Projects in Automobile Engineering

Published on January 2017 | Categories: Documents | Downloads: 38 | Comments: 0 | Views: 264
of 134
Download PDF   Embed   Report

Comments

Content

GURU TEGH BAHADUR POLYTECHNIC INSTITUTE

PROJECTS IN AUTOMOBILE ENGINEERING

PREPARED AND SUBMITTED BY: VINAYA C.MATHAD (LECTURER) GOPAL KUMAR (LAB ATTENDENT)

INDEX
1. HYBRID MOTORCYCLE……………………………….PAGE 02 2. KINETIC ENERGY RECOVERY SYSTEM…………………………………..PAGE 11 3. VARIABLE VALVE TIMING…………………………..PAGE 31 4. VARIABLE GEOMETRY INTAKE MANIFOLD…………………………………….PAGE 54 5. AUTOMATIC DIFFERENTIAL LOCKING SYSTEM……………………………………..PAGE 64 6. SEMI-AUTOMATIC ELECTRIC GEAR SHIFTIG APPARATUS FOR MOTORCYCLES…………………………………..PAGE 76 7. ELECTROMAGNETIC SHOCK ABSORBER………………………………………………..PAGE 83 8. ELECTRICALLY POWERED STEERING MECHANISM…………………………….PAGE 96 9. AUTOMATIC WINDOW WIPER CONTROL …………………………………….PAGE 104 10. PARKING AIR CONDITIONING

SYSTEM………………………………………………..PAGE 115
1

11
HYBRID MOTORCYCLE

ABSTRACT In recent years, hybrid motor vehicles configured to travel by using a driving force generated by an electric motor in addition to an engine power have been developed. Such hybrid vehicles have been commonly applied to four-wheeled motor vehicles and are now expected to be applied to two-wheeled motor vehicles. A motorcycle in which an engine is disposed between a front wheel and a rear wheel and an exhaust pipe for guiding exhaust gas emitted from the engine is extended forward relative to the engine, including an electric motor that is disposed behind a cylinder portion of the engine and is configured to apply a torque to a power transmission system including a crankshaft of the engine. The project relates to a hybrid motorcycle that is equipped with an engine mounted between a front wheel and a rear wheel and an electric motor configured to propel the motorcycle, and includes an exhaust pipe that is coupled to the engine and is extended forward relative to the engine. When an electric motor is incorporated into a motorcycle, it is desirable to dispose the electric motor in a location where the electric motor is less susceptible to disturbances in the environment for the purpose of stable operation, because the electric motor operates on electric power. Furthermore, it is necessary to mount the electric motor efficiently in a limited space of the motorcycle so as not to increase the size of a vehicle body of the motorcycle.

SUMMARY The project addresses the above described conditions, and an object of the present invention is to provide a hybrid motorcycle configured to be driven by an engine and an electric motor suitably disposed therein. In such a construction, the exhaust pipe, elevated in temperature because of high-temperature exhaust gas emitted from the engine and flowing therein, is extended forward relative to the engine, whereas the electric motor is disposed behind the cylinder portion of the engine on the opposite side of the exhaust pipe. Therefore, the electric motor is less susceptible to heat radiation from the exhaust pipe. As a result, the electric motor can operate stably.

2

The engine may include a cylinder block forming the cylinder portion and a crankcase disposed at a lower portion of the cylinder block. The exhaust pipe may be extended rearward from a region forward of the cylinder block through a region below the crankcase. The electric motor may be disposed in a space formed behind the cylinder block and above the crankcase. In such a construction, since the electric motor is disposed in the space behind the cylinder block and above the crankcase, the size of the vehicle body is not substantially increased. In addition, since the exhaust pipe elevated in temperature is extended through the region below the crankcase whereas the electric motor is disposed above the crankcase, the electric motor is less susceptible to heat radiation from the exhaust pipe. As a result, the electric motor can operate more stably. The electric motor and the crankshaft may be coupled to each other laterally of the crankcase via a chain and sprocket mechanism. A frame member may be extended rearward from a head pipe for supporting the front wheel, a swing arm extending substantially forward and rearward may be pivoted at a front portion thereof to the frame member, and the rear wheel is rotatably mounted to a rear portion of the swing arm. The electric motor may be disposed forward relative to the connecting point where the swing arm and the frame member are coupled to each other. In such a construction, since the electric motor is disposed between the connecting point where the front portion of the swing arm is coupled to the frame member and the cylinder portion of the engine so that the heavy weight of the electric motor is positioned near the center of gravity of the motorcycle. Therefore, weight of the motorcycle is well-balanced. The motorcycle may further comprise a starter motor configured to apply a torque to the crankshaft to start the engine, a first electric power supplying unit configured to supply an electric power to the starter motor, and a second electric power supplying unit configured to supply the electric power to the electric motor and to have a voltage higher than a voltage of the first electric power supplying unit. The first electric power supplying unit may be configured to be able to be charged with the electric power supplied from the second electric power supplying unit. In such a construction, since the first electric power supplying unit configured to supply the electric power to the starter motor is charged with the electric power supplied from the second electric power supplying unit configured to supply the electric power to the electric motor, there is no need for an electric generator for charging the first electric power supplying unit. As a result, the size of the vehicle body is not substantially increased.

3

DETAILED DESCRIPTION

As shown in FIG. 1, the motorcycle 1 includes a front wheel 2 and a rear wheel 3. The front wheel 2 is rotatably mounted to a lower end portion of a front fork 4 extending substantially vertically. The front fork 4 is mounted on a steering shaft (not shown) by an upper bracket (not shown) attached to an upper end portion thereof, and an under bracket located below the upper bracket. The steering shaft is rotatably supported by a head pipe 5 externally attached to the steering shaft. A bar-type steering handle 6 extending rightward and leftward is attached to the upper bracket. When the rider rotates the steering handle 6 clockwise or counterclockwise, the front wheel 2 is turned to a desired direction with the steering shaft. A fuel tank 7 is disposed behind the steering handle 4. A straddle-type seat 8 is disposed behind the fuel tank 7. A pair of right and left main frame members 9 (only left main frame member 9 is illustrated in FIG 1 ) forming a frame of a vehicle body extend to be tilted slightly downward and rearward from the head pipe 5. A pair of right and left pivot frame members (left pivot frame member is illustrated in FIG. 1) 10 are coupled to rear portions of the main frame members 9. A swing arm 11 extending substantially forward and rearward is pivotally mounted at a front end portion thereof to each pivot frame member 10. The rear wheel 3 which is a drive wheel is rotatably mounted to a rear end portion of the swing arm 11. An engine E is mounted on the right and left main frame members 9 and the pivot frame members 10 in such a manner that the engine E is disposed below the main frame members 9 and forward of the pivot frame members 10. A cowling 17 extends from a front portion to side portions of the vehicle body to cover the engine E and other components.

4

The engine E is an in-line four-cylinder engine. The engine E includes a cylinder block 44 that extends substantially vertically and has four cylinder portions aligned rightward and leftward, and a crankcase 15 that extends substantially horizontally rearward from a lower portion of the cylinder block 44 and accommodates the crankshaft 16 therein. In the engine E, the cylinder block 44, which is tilted slightly forward, and the crankcase 15 form a substantially L-shape in a side view. The cylinder block 44 includes a cylinder block body 12 for slidably accommodating a piston 24 therein, a cylinder head 13 that is coupled to an upper portion of the cylinder block body 12, forms a combustion chamber with the cylinder block body 12, and accommodates a DOHC valve system, and a cylinder head cover 14 covering an upper portion of the cylinder head 13 from above. An electric motor M for propelling the motorcycle 1 is disposed in a space formed behind the cylinder block 12 and above the crankcase 15 in a location forward of a connecting point A where the swing arm 11 and the pivot frame member 10 are coupled to each other. A first sprocket 46 is mounted on a left end portion of an output shah Mc of the electric motor M. A second sprocket 47 is mounted on a left end portion of the crankshaft 16. An inverted tooth chain referred to as a silent chain 33 is wound around the first sprocket 46 and the second sprocket 47 to transmit a rotational force from the electric motor M to the crankshaft 16. An intake port 18 opens in a rear portion of the cylinder head 13 of the engine E. A throttle device 19 is disposed inside the main frame members 9 and is coupled to the intake port 18. The electric motor M is positioned below a connecting point where the intake port 18 and the throttle device 19 are coupled to each other. An air cleaner box 20 is disposed below the fuel tank 7 and is coupled to an upstream portion of the throttle device 19 in an intake-air flow direction. The air cleaner box 20 takes in the air from outside by utilizing wind blowing from forward (ram pressure). An exhaust port 21 opens forward and downward at a front portion of the cylinder head 13. An upstream end of an exhaust pipe 22 is coupled to the exhaust port 21. The exhaust pipe 22 is extended forward from the exhaust port 21 of the engine E and then downward, and is further extended rearward through a region below the crankcase 15 of the engine E to a muffler 23 located behind. At desired locations below the seat 8, a large second electric power supplying unit 34, an inverter 35, a motorcontroller36, a small first electric power supplying unit 42, and a DC/DC converter 43 are mounted.

5

FIG. 2 is a block diagram of the motorcycle 1. As shown in FIG. 2, the crankcase 15 accommodates the crankshaft 16 coupled to connecting rods 25 of the pistons 24 of the engine E, and a first clutch gear 26 is mounted on the crankshaft 16. A second clutch gear 28 is rotatably externally fitted to a main shah 27 and is enmeshed with the first clutch gear 26. In a state where a main clutch 29 fixedly mounted on an end portion of the main shah 27 is engaged with the second clutch gear 28, the main shaft 27 is rotatable in association with the crankshaft 16. A counter shah 31 is coupled to the main shaft 27 via a gear train 30 so that the counter shah 31 can change its rotational speed. The counter shaft 31 is coupled to the rear wheel 3 via the chain 32. A path extending from the crankshaft 16 to the rear wheel 3 via the main shaft 27, the countershaft 31, and other components is a power transmission system. Torque from the electric motor M is transmitted to the crankshaft 16 via the first sprocket 46, the silent chain 33, and the second sprocket 47. Electric power is supplied from the second electric power supplying unit (e.g., battery of 144 voltage) 34 to the electric motor M via the inverter 35. A motor controller 36 is coupled to the inverter 35. The motor controller 36 controls driving timing and the torque of the electric motor M. A crank angle sensor 37 configured to detect a rotational angle of the crankshaft 16, a throttle valve opening degree sensor 38 configured to detect an opening degree of a throttle valve (not shown) disposed within the throttle device 19 (FIG. 1), a vehicle speed sensor 39 configured to detect a traveling speed of the motorcycle 1, a gear position sensor 40 configured to detect a gear position of the gear train 30 in the crankcase 15, are communicatively coupled to the motor controller 36. Torque from a starter motor 41 of the engine E is transmitted to the crankshaft 16. The starter motor 41 is configured to have a power output that is smaller than a power output of the electric motor M. The starter motor 41 is configured to be driven upon the rider turning on a starter switch (not shown) at the start of the engine E. The starter motor 41 is supplied with electric power from the first electric power supplying unit 42 (e.g., battery of 14 voltage) for supplying the electric power to an electric system of the motorcycle. The first electric power supplying unit 42 is coupled to the second electric power supplying unit 34 through a DC/DC converter 43. When the electric motor M is used as an electric generator, the generated electric power can be supplied to the second electric power supplying unit 34 and the electric power accumulated in the second electric power supplying unit 34 is decreased in voltage in the DC/DC converter 43 and is supplied to the first electric power supplying unit 42. FIG. 3 is a perspective view of the electric motor M mounted in the motorcycle 1. As shown in FIG. 3, the electric motor M includes a cylindrical motor body Ma and a flange portion Mb provided at a left end portion of the motor body Ma. Bolt holes Md and Me are formed at desired locations on a periphery of the flange portion Mb. An output shaft Mc protrudes leftward from a center of the flange portion Mb. Plate-shaped mounting portions Mf and Mg having bolt holes protrude forward and backward from a peripheral surface of the motor body Ma. A plate-shaped mounting portion Ml having a bolt hole protrudes rightward from a right end surface of the motor body Ma.

6

FIG. 4 is a side view schematically showing a state in which the electric motor M is mounted to the vehicle body of the motorcycle 1. FIG. 5 is a rear view taken in the direction of an arrow V of FIG. 4. In FIG. 4, for easier understanding, a cover 4X shown in FIG. 5 is omitted. As shown in FIGS. 4 and 5, the electric motor M is disposed in a space formed behind the cylinder block body 12 and above the crankcase 15. A bracket 45, which is a metal plate, is mounted to a left side surface of the crankcase 15 of the engine E so as to protrude to a left end surface of the electric motor M. Bolt holes 45a to 45^f are formed on the bracket 45 in locations corresponding to the le^n side surface of the crankcase 15 of the engine E and in locations corresponding to the bolt holes Md and Me of the electric motor M. As shown in FIG. 5, a penetrating hole 45g into which the output shah Mc of the electric motor M is inserted and a penetrating hole 45h into which the crankshaft 16 is inserted are formed on the bracket 45. The first sprocket 46 mounted on a left end portion of the output shaft Mc and the second sprocket 47 mounted on the le^n end portion of the crankshaft 16 are disposed on the left side ofthe bracket 45. The cover48 in which the first sprocket 46, the second sprocket 47 and the silent chain 33 wound around the first sprocket 46 and the second sprocket 47 are accommodated is mounted on the left side surface of the bracket 45. The cover 4X includes an accommodating portion 48a having a concave cross-section, and flange

7

portions 48b and 48c that protrude in flange shape from a peripheral edge of the accommodating portion 48a and having bolt holes (not shown). As shown in FIGS. 4 and 5, bolts B1 are inserted into the bolt hole (not shown) of the flange portion 48b of the cover 48, the bolt holes 45a to 45d of the bracket 45, and the bolt holes (not shown) of the left side surface of the crankcase 15 of the engine E to fasten the cover 48, the bracket 45, and the engine E to each other. Bolts B2 are inserted into the bolt hole (not shown) of the flange portion 48c of the cover 48, the bolt holes 45e and 45f of he bracket 45, and the bolt holes Md and Me (FIG. 3) of the flange portion Mb of the electric motor M to fasten the cover 48, the bracket 45, and the electric motor M to each other. As shown in FIG. 4, the rear mounting portion Mf of the electric motor M is placed on an upper surface 15a of a rear portion of the crankcase 15 of the engine E and is fastened to the upper surface 15a by a bolt B3. The front mounting portion Mg of the electric motor M is placed on an upper surface 12a formed on a back surface of the cylinder block body 12 of the engine E and is fastened to the upper surface 12a by a bolt B4. As shown in FIG. 5, the right mounting portion Ml^l of the electric motor M is placed on an upper surface 15bofarightportionofthe crankcase 15 ofthe engine E and is fastened to the upper surface 15b by a bolt B5. In the above construction, as shown in FIG. 1, the exhaust pipe 22, elevated in temperature because of exhaust gas emitted from the engine E and flowing therein, is extended from the cylinder block 12 forward relative to the engine E, whereas the electric motor M is disposed behind the cylinder block 12 of the engine E on the opposite side of the exhaust pipe 22. So, the electric motor M is less susceptible to heat radiation from the exhaust pipe 22. In addition, the exhaust pipe 22 extends through a region below the crankcase 15, whereas the electric motor M is disposed above the crankcase 15. So, the electric motor M is less susceptible to heat radiation from the exhaust pipe 22. Thus, the electric motor M is not substantially affected by disturbances such as heat. As a result, stable operation of the electric motor M can be achieved. Furthermore, since the electric motor M is disposed in the space formed behind the cylinder block 12 and above the crankcase 15 in the engine E in which the cylinder block 12 and the crankcase 15 form the substantially L-shape in the side view, space efficiency improves, and increase in the size of the vehicle body can be suppressed.The electric motor M is disposed forward relative to the connecting point A where the front portion of the swing arm 11 is coupled to the pivot frame member 10, and behind the cylinder block 12 of the engine E so that the heavy weight of the electric motor M is mounted at a location near the center of gravity of the motorcycle 1. As a result, stability of the motorcycle 1 is improved. As shown in FIG. 2, the first electric power supplying unit 42 for supplying the electric power to the starter motor 41 is charged with the electric power from the second electric power supplying unit 34 for supplying the electric power to the electric motor M. This eliminates a need for an electric generator for charging the first electric power supplying unit 42. As a result, increase in the size of the vehicle body can be further suppressed. As shown in FIGS. 4 and 5, since the electric motor M is fixedly mounted to the engine E side, a distance between the output shaft Mc of the electric motor M and the crankshaft 16 is constant regardless of occurrence of great vibration through the vehicle body. As a result, the silent chain 33 operates stably as compared to the construction in which the electric motor M is fixedly mounted to the vehicle body frame side.
8

Whereas the bracket 45 for mounting the electric motor M is mounted between the electric motor M and the engine E separately from the electric motor M and the engine E, it may alternatively be integral with an outer wall of the engine E. In further alternative, the electric motor M may be mounted to the vehicle frame side instead of the engine E side. Whereas batteries for converting electric energy to chemical energy through a chemical reaction and accumulating the chemical energy therein are used as the first electric power supplying unit 41 and the second electric power supplying unit 34 in this embodiment, capacitors or the like for accumulating electricity as electric charges may be used. Any other electric power accumulating devices may be used so long as they can accumulate and supply the electric power. Whereas the DC/DC converter 43 is disposed between the first electric power supplying unit 42 and the second electric power supplying unit 34 in this embodiment, it may be omitted if the first electric power supplying unit 42 can be charged with the electric power from the second electric power supplying unit 34 without a need for the DC/DC converter. Moreover, the number of cylinders equipped in the motorcycle of the present invention is not intended to be limited.

CONCLUSION 1. A motorcycle in which an engine is disposed between a front wheel and a rear wheel and an exhaust pipe for guiding an exhaust gas emitted from the engine is extended forward relative to the engine, the motorcycle comprising: an electric motor that is configured to apply a torque to a crankshaft of the engine; wherein the engine includes a cylinder block that extends substantially vertically and a crankcase that extends substantially horizontally rearward from a lower portion of the cylinder block, and the cylinder block and the crankcase form a substantially L-shape in a side view; wherein the exhaust pipe is extended rearward from a region forward of the cylinder block through a region below the crankcase; wherein a frame member is extended rearward from a head pipe for supporting the front wheel, a swing arm extending substantially forward and rearward is pivoted at a front portion thereof to the frame member, and the rear wheel is rotatably mounted to a rear portion of the swing arm; wherein the electric motor is disposed forward relative to a connecting point where the swing arm and the frame member are coupled to each other, and is disposed in a space formed behind the cylinder block and above the crankcase; and wherein the electric motor is fastened to the engine, and torque from the electric motor is transmitted to the cranksha^n. 2. The motorcycle according to claim 1, further comprising: a starter motor configured to apply a torque to the cranksha^n to start the engine; a first electric power supplying unit configured to supply an electric power to the starter motor; and a second electric power supplying unit configured to supply the electric power to the electric motor and to have a voltage higher than a voltage of the first electric power supplying unit; wherein the first electric power supplying unit is configured to be able to be charged with the electric power supplied from the second electric power supplying unit. 3. The motorcycle according to claim 1, wherein the electric motor is positioned below a connecting point where an intake port of the engine and a throttle device are coupled to each other.
9

4. The motorcycle according to claim 1, wherein a bracket is mounted to a left side surface of the crankcase so as to protrude to a le^n end surface of the electric motor, and the bracket is fastened to the left end surface of the electric motor by a bolt. 5. The motorcycle according to claim 4, wherein the bracket is a metal plate. 6. The motorcycle according to claim 4, wherein a penetrating hole into which the output shaft of the electric motor is inserted and a penetrating hole into which the crankshaft is inserted are formed on the bracket. 7. The motorcycle according to claim 4, wherein a first sprocket mounted on a le^n end portion of the output shaft and a second sprocket mounted on a le^n end portion of the crankshaft are disposed on a left side of the bracket. 8. The motorcycle according to claim 7, wherein a cover in which the first sprocket, the second sprocket and a chain wound around the first sprocket and the second sprocket are accommodated is mounted on a left side surface of the bracket. 9. The motorcycle according to claim 8, wherein the cover, the bracket and the crankcase are fastened to each other by a bolt, and the cover, the bracket and the electric motor are fastened to each other by a bolt. 10. The motorcycle according to claim 1, wherein the electric motor is fastened to an upper surface of a rear portion of the crankcase by a bolt and is fastened to a back surface of the cylinder block by a bolt.

**************

10

KINETIC ENERGY RECOVERY SYSTEM

ABSTRACT A motor vehicle kinetic energy recovery system uses one or more cylinders of an internal combustion engine as the first or primary stage in a multi-stage high pressure air compression system, a compressed air storage system, compressed air operated drive train boosters and vehicle management electronics to provide cooperation between the air compression, storage and booster systems. The multi-stage, high pressure air compressor system is operable through engine compression braking allowing kinetic energy of a vehicle to be recaptured during retardation of vehicle speed.

OBJECTIVE 1. To improve the efficiency of motor vehicles equipped with internal combustion engines. 2. To provide recovery ol kinetic energy of a vehicle during driver or speed control system initiated vehicle speed retardation. 3. To utilize compressed air to provide supplemental torque for an internal combustion engine. 4. To combine vehicle operational data to identify efficient opportunities for capture of kinetic energy for storage and reuse for vehicle speed boosting.

11

SUMMARY

Most motor vehicles equipped with internal combustion engines dissipate kinetic energy during stopping through use of friction brakes and engine compression braking, rather than capturing and storing the energy for reuse. It is widely recognized that this arrangement is highly wasteful of energy and that recapture of the energy for use in moving the vehicle from standing starts is desirable. However, prior attempts to provide for recapture of the energy for reuse, as represented by hybrid gasoline/electric vehicles, have been difficult to justify economically at low energy prices. These vehicles use both an internal combustion engine and electric motors to move the vehicle. During braking the motors operate as generators to retard the vehicle and convert the vehicle's kinetic energy to electricity which is stored in batteries. This power can then be used to power the motors and move the vehicle. Such vehicles are highly efficient. However, they are also very complex and as a result cost substantially more to design and build than conventional vehicles. They also have high maintenance costs associated with periodically replacing the battery plant. An effective energy recovery system for a vehicle using an internal combustion engine must provide for the efficient storage of the recaptured energy. Alternatives to battery storage include fly wheels and compressed air. Implementation of systems based on these alternative modes of energy storage have been hobbled by the limitations of the recapture and utilization mechanisms. Considering compressed air systems in particular, designers have typically looked to clutching the wheels to air pumps to provide vehicle speed retardation and a source of high pressure air. This has been done notwithstanding the fact that the engine itself is a pump, is connected to some of the wheels by the vehicle's drive line and can be used for engine compression braking. Unfortunately, even diesel engines, when operated as pumps, operate at too low of a pressure to provide an efficient and compact kinetic energy capture and utilization system. Engine compression braking is implemented by operating an internal combustion engine as an air compressor and then dissipating the energy stored compressing the air through the vehicle's exhaust. In order to run a diesel as a compressor, fuel flow is cut off to one or more the engine's cylinders. The vehicle's momentum is coupled back to the engine crankshaft by the vehicle drive train causing the pistons in the non-firing cylinders to continue to cycle. The cylinders' intake valves operate to allow air to be drawn for compression strokes, but the cylinders' exhaust valves are opened at or just before top dead center (TDC) of the pistons' compression cycles to exhaust the air, releasing the energy potential of the compressed gas air. The energy is dissipated in friction upon release to the open atmosphere. Internal combustion engines operate as relatively low compression pumps. A diesel may generate approximately a 25 to 1 compression ration, meaning that air drawn into the cylinder at close to ambient pressure is compressed to no greater than about 375 psi. In practice only about 300 psi is achieved due to a partial vacuum in the intake manifold and frictional losses. Absent some modification of a cylinder to operate as a higher compression pump, which
12

complicates the engine and may compromise its performance, the compressed air must be recovered from the exhaust manifold, which entails storage at a still lower pressure. Assuming that air of sufficient pressure can be made available to propel the vehicle on taking of from a standing start, a question has also remained of how, and when, to make use of the compressed air. Also of interest is when and how to run the engine for air compression to optimize vehicle operation and reduce pollution. What is needed is a way of boosting pump operation of an internal combustion engine on a vehicle to sufficiently high pressures to be used for moving the vehicle, all while minimizing changes to the vehicles drive train and engine to produce a system both economical and reliable. The project provides a vehicle with a multi-cylinder diesel engine which can be operated in a split mode with one or more cylinders diverted to operation as air compressor stages or adapted for use for engine compression braking. Valves are incorporated into the exhaust pipes for selected cylinders which may be closed to prevent or delay exhaust venting from the exhaust pipes. Fluid amplifiers communicate with these exhaust pipes to operate as second stage high compression pumps. Compressed air from the second stage compressors is delivered to a high pressure storage tank for later use to meet high transient torque demand. In the preferred embodiment, high pressure air is used to drive a hydraulic motor coupled to an automatic or semi-automatic transmission and thereby displace torque demands on the engine, especially at takeoff from a standing start. Alternatively, the air may be delivered to an exhaust turbine in a turbo-compounding arrangement to provide additional torque to the engine output shaft. Air may also be forced into the intake manifold of the engines for take offs from a standing start by released compressed air to the drive turbine of a turbosupercharger.

DETAILED DESCRIPTION FIG. 1 illustrates in a perspective view a truck tractor 10 comprising a cab 11 mounted on a chassis 12. A plurality of wheels 13 depend from the chassis. Tractor 10 includes conventional major systems for a vehicle, including a drive train having a diesel engine and a transmission. Tractor 10 also includes air powered drive train boosters as described below. The invention is preferably applied to medium and large trucks which have compressed air systems for brake operation or for starting. These vehicles are typically equipped with a multi-cylinder diesel, which is often adapted for engine compression braking, and compressed air tanks. It will be understood that while the invention is preferably applied to diesels, it would also work, with modification, on internal combustion engines using spark initiated combustion. It may also be advantageously applied to delivery trucks and other vehicles used heavily for stop and go driving.

13

Referring now to FIG. 2 an engine air compression and diversion system 18 is illustrated. Compression system 18 uses one or more of the cylinders 32 of a bank 24 of cylinders of a multi-cylinder diesel engine as first stage pumps. In normal operation a piston 102 moves in a conventional, reciprocating fashion within a cylinder 32 with the result that space 104
14

between the piston and valves 106 and 110 varies in volume. A diesel is conventionally operated as a four cycle engine. Initially intake valve 106 and exhaust valve 110 may be assumed closed. The first cycle is initiated with piston 102 at the top of its travel in cylinder 32 (referred to conventionally as top dead center ("TDC"). Intake valve 106 is opened and air is drawn into cylinder 32 with the following downstroke of piston 102 through the opened intake valve 106 from an intake manifold 108. Intake valve 106 is closed when piston 102 reaches the bottom of its travel in the piston and the air is compressed by the subsequent upward movement of piston 102. This compression stroke of piston 102 develops an approximately 25 to 1 compression ratio of air in the cylinder, raising the temperature of the air above the ignition point of the fuel. Compression ignition of the fuel results upon fuel being injected into cylinder 32 as the piston approaches TDC. The burning air fuel mixture substantially raises pressure in cylinder 32 substantially increasing the downward force on piston 102. This produces a downward power stroke of piston 104. An upward exhaust stroke of piston 102 follows for which exhaust valve 110 is opened. During the exhaust stroke the combustion byproduct is exhausted through exhaust valve 110 into a cylinder exhaust chamber 112. Exhaust chamber 112 can pass air or combustion byproducts from cylinder 32 to an exhaust manifold 17, which collects exhaust gas from bank 24 of cylinders, or retain the air for use of the fluidic amplifier 83. Exhaust valve 110 closes as piston 102 finishes the exhaust stroke. The four cycles repeat as long as the cylinder is firing. Contemporary practice provides for computer based control of many vehicle and engine functions, usually organized by systems. An engine controller 20 is representative of such a computer used to monitor and control the operation of diesel 16. Engine controller 20 times fuel injection to each cylinder 32 by control of a fuel injection controller 48. A camshaft rotates in synchronous with a crank shaft, which in turn is coupled to the pistons in cylinders 32. Thus camshaft position is related to the phase of each piston relative to TDC. Fuel injection is timed in relation to the cam phase position, provided by a cam phase (engine position) sensor 42. Fuel injection is handled by an injector controller 48. The timing of closing and opening of the intake valve 106 and an exhaust valve 110 are effected by engine controller 20 through valve actuators 124 and 126, respectively. Engine controller 20 is also used to operate a starter 50, which may be an air starter using compressed air from a compressed air tank 70. Where an air starter, or some other device using compressed air at the request of engine control module 20 is used, the engine control module is connected to control a solenoid 87 for positioning a valve 85. Air valve 85 connects compressed air tank 70 to the device, here an air starter 50, or as described hereinafter, a torque output booster. The pistons of an engine are connected to a rotatable crankshaft (not shown) which is in turn connected to an output shaft and transmission which continue to move the pistons absent fuel flow to the cylinders, as long as the vehicle retains momentum. The intake and exhaust valves 106, 110 may be hydraulically actuated using pressurized engine oil, with the camshaft used to operate hydraulic valves controlling intake and exhaust valve operation. Hydraulic valve control may then be overridden by engine controller 20 through valve controllers 124 and 126. For future camless engines, crankshaft phase position may be substituted for cam phase position to the same effect in coordinating the injection of fuel with piston phase and valve timing. In a camless engine, hydraulic valve control uses pressurized engine oil and remains under the control of valve controllers 124 and 126. The position of an exhaust collection shutter valve 34 is coordinated by engine controller 20 using a solenoid 35 as described below.

15

Engine operation as an air pump requires coordination of the operation of fuel injectors, intake valves, exhaust valves and the exhaust diversion valves. Engine cylinders are operated as pumps in split mode operation, or during engine compression braking. Pump operation entails fuel flow cut off to one or more cylinders 32. Cylinder 32 operates as an air pump when at least some of the remaining cylinders of the engine continue to fire to keep the engine turning over, or when vehicle momentum is coupled to the engine crankshaft from the transmission. After fuel is cut off to a pumping cylinder, the cam actuated lifters can continue to operate intake and exhaust valves 106 and 110, however, for more efficient engine compression braking, the intake valve is open during every down stroke and the exhaust valve is briefly opened as the piston 102 approaches TDC with every up stroke. Under conditions where some engine power is required, but air pressure status indicates a need for air, valve operation may be altered, and still allow operation of the high pressure air compression system 18. It is not usually necessary under these conditions to draw air to a pumping cylinder 32 and it is preferable not to draw air away from the firing cylinders, or to impose as large a load on the engine as would occur if the non-firing cylinder of the engine were operating, in effect, as a compression brake. For a preferred embodiment of a fluidic amplifier 83, the intake valve 106 may be left closed and the exhaust valve 110 left open after an initial air charge is drawn into cylinder 32 and the fluidic amplifier 83 will continue to supply high pressure air, at least as long as the charge does not leak away. To compensate for such leakage the charge in the pumping cylinder 32 may be occasionally refreshed by opening intake valve 106 during a cycle. Cylinder 32 operates as the first, or low pressure stage, of a two stage pump. Compressed air from cylinder 32 is used to drive a second or high pressure stage pump. In order to avoid modification of the cylinder 32, some modification of the exhaust manifold 17, or to the exhaust chamber 112 from an individual cylinder, is required to divert the air to drive the high pressure pumps. Shutter valve 34 is located in the wall of exhaust chamber 112 and connects the chamber with exhaust manifold 17. A fluidic amplifier 83, which provides the high pressure stage, communicates with the exhaust chamber 112. Modification of the exhaust system for one cylinder 32 to accommodate one shutter valve 34 and fluidic amplifier 83 is illustrated, but it will be understood that an exhaust system can be modified allowing more than one of cylinders 32 to operate as first stage air pumps. It will also be understood that cylinders may have more than one intake or exhaust valve and that illustration of and reference to the cylinders as having a single valve for exhaust and a single valve for intake has been done for the sake of simplicity in illustration only. Retention of air pumped from cylinder 32 is controlled by opening and closing shutter valve 34. A control solenoid 40, under the control of engine controller 20, positions valve 34. When valve 34 is closed, and fuel cut off from cylinder 32, air is pumped from cylinder 32 during an up stroke into fluidic or pneumatic amplifier 83. Pneumatic amplifier draws air from the environment through an intake 183, compresses the air and exhausts the compressed air through a check valve 120 into a high pressure air tank 70. Fluid amplifier 83 should have a pressure gain of about 20 to 1 and thus be able to deliver air to compressed air tank at pressures in excess of 2000 psi or twenty times the expected pressure of air from cylinder 32. Shutter valve 34 also operates to release air from the input side of pneumatic amplifier 83 upon opening, which can occur after a brief delay or during engine compression braking or only after pumping is discontinued, as may be preferred for split mode operation. Fluid amplifier 83 could in theory be run from combustion by product exhaust gas from cylinder 32 at substantially higher pressures, however, such an arrangement would substantially increase
16

back pressure from the exhaust system and thereby reduce the efficiency of the engine. The 2000 psi pressure level is chosen as the contemporary practical economic limit for a motor vehicle compressed air storage system. A higher pressure could be used given progress in seals and tank strength at affordable prices for a mass produced vehicle. Air compression occurs in response to a need for compressed air and availability of engine power to provide energy for pumping. A need for air is indicated by a downward variance from the maximum pressure limit for air tank 70. To provide air tank 70 pressure readings, a pressure sensor 91 is provided in fluid communication with air tank 70. Pressure sensor 91 reports air pressure in tank 70 to a computer, preferably body controller 30, or to engine control module 20, depending upon the particular control arrangements provided on a given vehicle. When air pressure in air tank 70 is below the maximum allowed a request for operating air compression system 18 is issued by body controller 30. The degree to which the air pressure falls below the maximum allowed may also be used as an indication of the priority of the request. In order to avoid frequent cycling of the system on and off, air pressure in tank 70 may be required to fall a certain minimum amount below the maximum limit before air compression system 18 is engaged. A number of control regimens may be implemented and which regimen is used at a given time may depend upon the pressure level short fall. Described here are the mechanisms useful in implementing the regimens. The regimens are executed by body controller 30. This computer may also be referred to in the art as a chassis controller or system controller. The functions are implemented on International Truck & Engine vehicles by an electrical system controller. Finding the preferred periods for operation of the air compression system 18 also requires determining engine load or some other related factor indicative of spare engine capacity. If engine load is low, or better still negative, air compression system 18 can be run at little penalty, and more usually allows energy to be recaptured. Periods of engine compression braking are an ideal opportunity for air compression system 18 operation. Bodycontroller 30 estimates engine load from engine speed, derived from the output of the engine (or cam phase) position sensor 42 and the fuel flow output which are passed to it from engine control module 20. Body controller 30 also receives inputs, either directly or from other system controllers, which indicate the status or condition of an accelerator pedal/torque request input 54, a starter button 56, an ignition switch 58, a brake pedal position switch 58 and a vehicle speed indication source 59, all of which may be used to determine other opportunities to initiate air pumping or the need to use air. Under cruising conditions where air tank 70 is fully pressurized, and no demands for air power occur, body controller 30 may determine leakage rates for air tank 70 from periodic sampling of readings from pressure sensor 91. A preferred embodiment of the invention will now be described with reference particularly to FIGS. 3A-D where a schematic of the pneumatic amplifier 83 and shutter valve 34 are illustrated. Pneumatic amplifier 83 comprises an exhaust chamber 112 which functions as a pneumatic amplifier input chamber. Exhaust chamber 112 is exposed to a working surface 308 of a shuttle piston 304. Shuttle piston 304 is positioned between chamber 112 and pumping chamber 320. Shuttle piston 304 is mounted to reciprocate in the directions indicated by the double headed arrow "C" allowing air in a pumping chamber 320 to be compressed. A working surface 310 of piston 312 is exposed to pumping chamber 320. Working surface 308 has approximately 20 times the exposed surface area of working surface 310 meaning that the pressure in pumping chamber 320 balances the pressure in chamber 302
17

when it is about 20 times as great, less the rebound force generated by a compression spring 312. Spring 312 is disposed to urge shuttle piston 304 in the direction "D" up to a limit of the shuttle piston's travel. An intake 183 is provided to the pumping chamber 320, which admits air to the chamber through a one way check valve 314. The air drawn into the chamber is preferably dried ambient air. The spring constant of compression spring 312 is selected to substantially prevent movement of shuttle piston 304 during the relatively low transient pressures occurring during the exhaust of combustion gases.

FIG. 3A-3D, Shows the operation of a two stage high pressure air compressor system using an engine cylinder at first low pressure stage of the pump.

18

19

Shutter valve 34 is located in the wall of exhaust chamber 112 and is positioned to control pressurization of the chamber and operation of fluidic amplifier 83. Exhaust chamber 112 should be made as small as practical to minimize the pressure drop occurring in gas exhausted from cylinder 32 when shutter valve 34 is closed. As illustrated in FIG. 3A, valve 34 is in its opened position, allowing combustion by-products to escape from cylinder 32. With valves 32 and 34 open, reciprocating piston 102 can force exhaust gas from cylinder 32 through the opened exhaust valve 110 as indicated by arrow "A" into cylinder exhaust chamber 112 and out of exhaust chamber 112 through valve 34 as indicated by the arrow "B" to an exhaust manifold 17. In FIG. 3B pumping of compressed air into compressed air tank 70 is illustrated. Following cessation of fuel injection to cylinder 32 and having drawn a charge of air into cylinder 32, concurrent with compression stroke of piston 102, exhaust valve 110 opens to allow air to be forced from cylinder 32 indicated by arrow "A". Shutter valve 34 closes access to exhaust manifold 17 preventing the flow of air into the exhaust manifold. As pressure in exhaust chamber 112 increases, the resistance of spring 312 is overcome and shuttle piston 304 is forced in the direction indicated by the arrow "E", compressing the air in pumping chamber 320 until check valve 120 admits (in the direction indicated by arrow "G") the air to compressed air tank 70. Again the gain provided by the difference in exposed surface areas of the two ends of the pistons results in a gain of about 20 to 1 in pressurization. The relative areas may be varied to obtain almost any desired gain though. The relative volumes of the exhaust chamber 302 and the pumping chamber 320 and the travel of shuttle piston 304 are chosen so that shuttle piston 304 does not bottom against spring 312 before pressure in the chamber 320 increases sufficiently to balance the pressure in input chamber 302.

20

In FIG. 3C a pumping stroke of shuttle piston 304 has completed. Fluid amplifier 83 may be operated without drawing fresh air with each cycle into cylinder 32. Once a charge of air is drawn into cylinder 32, valves 106 and 34 are kept closed, and valve 110 left open. For subsequent pumping steps, as piston 104 moves downwardly, air is drawn from chamber 112 through exhaust valve 110 back into cylinder 32, pulling shuttle piston 304 back into chamber 302, and thereby drawing air in pumping chamber 320 by a now open check valve 314 as indicated by the arrow "I". Piston 102 reciprocates in cylinder 32 resulting in the same charge of air being forced in and out of exhaust chamber 112. Using this operational sequence it may be possible to eliminate compression spring 312, simplifying pneumatic amplifier 83. The effectiveness of such an arrangement will depend upon the quality of the seal formed by valve 34 and some leakage from exhaust chamber 112 is to be expected. Pumping in this manner may require pressure monitoring in chamber 112 and occasionally opening intake valve 106 may be done to replenish the charge. A pressurized first stage system might be employed where, rather than drawing a fresh air charge, pumping begins with a charge of combustion by product from cylinder 32. Again the intake valve 106 and shutter valve 34 remain closed and valve 110 would remain open while piston 102 reciprocates. Pumping with valve 106 held closed and valve 110 held open is preferably employed when the engine is under a positive load and it is undesirable that pumping mimic a compression brake or draw air from the intake manifold and thus divert it from the firing cylinders. FIG. 3D reflects the configuration of pumping system 18 for recharging fluidic amplifier 83 or for an intake stroke when the engine is being used for compression braking. Exhaust valve 110 to cylinder 32 has closed and intake valve 106 has opened as piston 102 begins an intake stroke, drawing air from intake manifold 108 into chamber 104. Shutter valve 34 opens allowing air in exhaust chamber 112 and exhaust pipe 118 to escape to the exhaust manifold 17. This results in a pressure drop in chamber 112 which allows a combination of air pressure in pumping chamber 320 and spring 312 to return shuttle piston 304 in the direction indicated by the letter "F" to a neutral position. With movement of the shuttle piston 304, air pressure drops below ambient pressure in pumping chamber 320 and air is drawn through intake 183 and check valve 314 into the pumping chamber. Referring now to FIGS. 4, 5 and 6, the preferred embodiments of the invention are illustrated. Diesel engine 16 is a simplified representation of the engine described above in connection with FIG. 2. The invention is employed to best effect when the various vehicle systems are monitored and data related to operating variables are exchanged between system control processes. This arrangement allows determination of advantageous times to compress air and further determines when there is a demand for air and the capacity to provide it. Compressed air may be applied to vehicle systems such as an air brake system 95 used by a trailer or by an air starter 50 used for starting a diesel engine. Compressed air at the high pressures efficiently recovered by the two stage air compression system described here can also be employed to provide supplemental torque on demand. Utilization of the air also depends upon vehicle operating conditions. In contemporary vehicles major vehicle systems, e.g. the drive train, the engine, the brake system, and so on, are increasingly under the control of system controllers. The system controllers, including an engine controller 20, a transmission controller 130, an anti-lock brake system (ABS) controller 99, a gauge controller 14, and body controller 30, communicate with one another over a controller area bus (CAN) 19, which in the preferred
21

embodiment conforms to the SAE J1939 protocol. CAN bus 19 provides the necessary means to distribute data on vehicle operating conditions and control vehicle operation to support implementation of the invention. CAN networks allow controllers to place non-addressed data on a bus, in standard formats which identify the character and priority of the data and which still other controllers coupled to the bus can be programmed to recognize and operate on. The different embodiments of the invention provide alternative means to utilize the available high pressure air, which are implemented using slightly different control arrangements. In a typical application the vehicle will incorporate an air brake system 95 which makes competing demands for compressed air. Requests of brake system 95 for air, which are initiated from the gauge controller 14, which monitors brake pedal position sensor 81, are afforded a higher priority than other demands for compressed air. Requests for air and determinations of when to pressurize air are determined only when the vehicle is on, as indicated by the position of an on/off switch 58, which may be monitored by gauge controller 14 or by body controller 30. ABS controller 99 may, in some vehicles, be utilized to determine vehicle speed from the wheel rotational speed sensors 97 or from transmission tachometer 170. Vehicle speed is used for determining when to use compressed air. A transmission controller 130 is provided on vehicles equipped with automatic or semiautomatic transmissions and provides gear selection for the transmission 150 based on engine speed, vehicle speed, available torque and torque demand. Engine controller 20 typically communicates with a tachometer 170 coupled to an output shaft from a transmission 150 to determine vehicle speed.

22

In the embodiment of FIG. 4 a hydrostatic motor 160 provides drive train boost on demand. Hydrostatic motor 160 is used to boost a transmission 150 normally driven by the output
23

shaft 152 from engine 16. Operation of hydrostatic motor 160 is supported by compressed air from a high pressure air tank 77. Air passes from air tank 70 through a check valve 130 and a valve 85 to hydrostatic motor 170. Valve 85 is positioned by a solenoid controller in response to a control signal from engine control module 20. Hydrostatic motor 160 directly boosts transmission 150 to meet part of the torque demand received by the engine controller 20 from body controller 30, which in turn determines torque demand from the position of an accelerator pedal 54 and torque availability for the engine by subtracting a load estimate from engine capacity (stored in look up tables). Engine controller 20 allocates the response between the hydrostatic motor 160 and engine 16 as a function of engine rpms (determined from cam phase sensor 42), the availability of compressed air in air tank 70, provided by a pressure sensor 91 through body controller 30, and vehicle speed. Engine 16 has a torque output curve as a function in engine rpm's and load which is low at low rpm's and climbs to a peak as rpm's increase. Supplemental torque is of greatest value for taking off from a standing start where no gear choice is available allowing for operation of the engine in an advantageous portion of the engine torque curve. Boost from hydrostatic motor 160 may also be used to limit loading on output shaft 152 from engine 16 to transmission 150, allowing the use of a lower weight crankshaft. Vehicles equipped with on board estimation of vehicle load can advantageously adjust the amount of boost to provide the desired acceleration while limiting the load on output shaft 52. Reducing torque loads on diesel engines also reduces piston blow-by, extending engine oil life and reducing particulate emissions. Exhaust from exhaust manifold 17 is handled conventionally being routed through an exhaust turbine 300 for a turbo-supercharger. Boost is tapered off as engine speed increases and more engine torque becomes available by progressively restricting flow through valve 85. Referring to FIG. 5, application of the invention in a turbo-compounded engine is illustrated. An exhaust turbine 250 is connected to exhaust manifold 17 and mechanically coupled to output shaft 152 in conventional fashion to boost the output to a transmission 150 from the crankshaft. Compressed air can be fed to the turbine 250 as a substitute for engine exhaust or mixed with the engine exhaust to boost the turbine's mechanical output. Back pressure in power turbine 250 is monitored using a turbine pressure sensor 207 which is connected to engine controller 20 for reporting readings. Providing boost to the output shaft through a power turbine is useful for vehicles for starting the vehicle from a standing start when exhaust back pressure is low. Air release here can be triggered by coincidence of a high torque request from body controller 30, low speed and by engine load increasing with the vehicle in gear. Referring to FIG. 6, a vehicle is equipped with a turbo-supercharger (comprising turbine 300 and supercharger 261, which forces air by way of a pressure regulator 262 to an engine intake manifold 108. Compressed air tank 70 is connected by check valve 130 and valve 85 to feed air to turbine 300 resulting in increased boost from supercharger 261 by way of pressure regulator 262 to intake manifold 108. Air pressure in intake manifold 108 is monitored by a pressure sensor 279 which feeds pressure readings to an engine controller 20. Air is forced into the intake manifold 108 upon occurrence of torque request, low vehicle speed, low engine speed and falling or low intake manifold pressure sensed by pressure sensor 279. Here, rather than supplying a direct torque boost, the invention promotes good combustion and reduces the intake pumping burden on engine 16 during starts thus providing an indirect boost to torque. Pressure sensor 279 provides feedback limiting for the amount of air released to the intake manifold. While compressed air could in theory be directed directly from the air tank 70 to intake manifold 108 it is considerably simpler from a design perspective to utilize existing supercharger boost arrangements and provide an alternative drive system for the
24

supercharger. Supercharger lag time may also be reduced by using compressed air to spin up the power turbine ahead of exhaust gas availability. For any of the embodiments, engine 16 load can be estimated by engine controller 20. Engine control module 20 determines fuel flow for injector controller 48 in response to torque requests from body controller 30. Engine load is related to brake mean effective pressure which
in turn can be estimated as the fuel flow divided by engine speed. Comparison of the result to a look up table keyed to engine rpm's allows determination of the amount of spare capacity available from a diesel. Referring to FIG. 7, a simplified flow chart illustrating operation of the invention is depicted. Vehicle braking has a priority claim on air and accordingly the initial step 700 is a determination if the brake system is engaged. If the brakes are engaged engine 16 may be used to help slow the vehicle and at step 702 engine compression braking is started. Next, at step 704, tank pressure is read and if it low, step 706 is executed to initiate two stage high pressure air compression. In order to maintain compression braking efficiency, air will be exhausted from the intermediate plenum of the two stage pumps rather than returned to the engine cylinders. If tank pressure does not require adding air, engine pumping may be omitted. Following the NO branch from step 704, or following step 706 the process loops to continue monitoring brake position. If the brakes are determined at step 700 to be disengaged, step 708 is executed to determine if air pressure is too low to permit use of air pressure to permit recovery of energy from the air. If may be noted that the tank pressure limit here may or may not be the same as that measured at step 704. Making the limit for step 708 lower than the limit for step 704 promotes air compression occurring during periods of braking rather than during any period when spare engine capacity is available. If air tank 70 pressure falls below the minimum required by step 708 the YES branch from the decision block is taken to step 710 where it is determined if the engine has a margin of spare capacity. If YES, split mode operation of engine 16 may be initiated at step 712 to allow some of the cylinders to be used to restore air pressure to a minimum desired level. Following the NO branch from step 710 or step 712 processing loops back through step 700 to determine brake position.

25

Following the YES branch from step 708 processing is advanced to the torque boost utilization steps using compressed air. It is preferred that use of compressed air for driving a hydrostatic motor or to feed the turbine of a turbo compound engine be implemented with over pressure recovered from vehicle braking and not from running the engine in a split mode under circumstances where engine compression braking is not required. This preference is implemented by limiting operation of the hydrostatic motor and turbocompounding boost to periods when tank pressure reflects pressure added by engine compression braking. However, for vehicles used as delivery vehicles in urban or suburban areas where there is a great deal idle time, another loop may be added following the NO branch from step 708 to allow split mode pressure operation during idle periods of the vehicle's engine. This air pressure is available for non-brake devices to reduce variability in engine rpm's. This type of operation can be energy efficient because the engine is allowed to operate at a constant rpm and it should be effective in reducing emissions.
26

Where the idle option is included, step 714 is executed following a NO decision at step 708 to determine if the transmission is in gear or out of gear. This information is supplied by the transmission controller 130. If the transmission is out of gear, split mode operation of the engine is permitted to boost tank 70 air pressure to the maximum allowed level. Following the "out of gear" determination, step 725 is executed to determine if tank pressure is at the maximum allowed level. If it is the process returns to the step 700. If not, split mode operation of the engine to add air is initiated at step 777 and processing returns to brake position determination step 700. Following determination that the transmission is reported to be in gear at step 714, step 716 is executed to determine if engine rpm's are falling. If YES, then step 720 is executed to determine if torque is being requested by the body controller 30. If this determination is also affirmative, then air is released to boost torque output at step 722. Following step 722 or the NO branch of step 720 process execution is returned to brake position determination at step 700. Following the NO branch from step 716, step 718 is executed to determine if vehicle speed is low, or stopped. If YES, step 720 follows. If NO, processing returns to the brake position determination step 700. If will be understood that the steps 716 and 718 could be rearranged, or that a step determining whether intake manifold pressure was low could be substituted if measuring for declining engine rpm's. Allocation of the load between the internal combustion engine and the pressurized air output boost system is determined by the engine controller 20 which varies the position of valve 85 to control flow of compressed air. Available torque from compressed air is readily determined empirically and stored in look up tables. The invention provides for recapturing and reusing kinetic energy otherwise lost during braking by employing temporarily unused or unneeded cylinders in a diesel engine as first stages in high pressure two stage air pumps. The energy is recycled in a number of ways to boost drive train output, such as deploying compressed air supply torque to the transmission using a hydrostatic motor, delivering the air to the turbine of an turbo-compound engine, or increasing intake manifold pressure by driving the power turbine for a turbo-supercharger. The consequential reduction in load on the engine during take off from a standing start or during periods climbing an upgrade which require low engine speed operation can reduce pollutant production otherwise characteristic of diesels at low rpms.

27

CONCLUSIONS 1. A motor vehicle comprising: an air storage tank mounted on the motor vehicle; a drive train including a transmission and an internal combustion engine having a plurality of cylinders, an exhaust pipe from each cylinder and a crank shaft for turning the a transmission; a multi-stage compressor including at least a first cylinder of the internal combustion engine for operation as a low pressure compression stage to pump air to the exhaust pipe for the first cylinder and a high pressure stage coupled to the exhaust pipe for the first cylinder for actuation and an outlet from the high pressure stage connected to supply high pressure air to the air storage tank; a controllable discharge valve from the air storage tank; and a drive train booster connected by the controllable discharge valve to the air storage tank for receiving pressurized air. 2. A motor vehicle as set forth in claim 1, further compnsing: a controller area network; an engine controller communicating with the controller area network and for determining engine load and engine torque capacity information and for implementing engine compression braking and split mode operation of the engine; a braking system for retarding vehicle velocity including through requests for engine compression braking placed on the controller area network; a pressure sensor associated with the air storage tank for generating pressure signals for the engine controller; and the engine controller being further responsive to a first minimum pressure sensor reading below the maximum allowed pressure for initiating operation of the multistage compressor during engine compression braking and still further responsive to pressure sensor readings below a second greater minimum threshold for initiating split mode operation engine and concurrently initiating operation of the multi-stage compressor during periods when the engine has excess capacity. 3. A motor vehicle as set forth in claim 2, wherein the drive train booster comprises a compressed air powered hydrostatic motor coupled to the transmission. 4. A motor vehicle as set forth in claim 2, wherein the drive train booster comprises a power
turbine coupled to the crankshaft.

5. A motor vehicle as set forth in claim 2, wherein the drive train booster comprises: a supercharger having an exhaust driven power turbine; and an intake manifold for the internal combustion engine coupled for boost from the supercharger. 6. A motor vehicle as set forth in claim 1, further comprising: a pressure sensor for the air storage tank; a body controller for estimating load on the internal combustion engine and for receiving pressure readings from the pressure sensor; the body controller being responsive to an estimate of a negative load on the internal combustion engine and a pressure reading below a maximum allowed level for the air storage tank for initiating pump operation of the at least first cylinder; and the body controller being further responsive to an estimate of a non-negative load on the internal combustion engine which leaves spare load capacity and a pressure reading for the air storage tank below a minimum limit for initiating split mode operation of the internal combustion engine and pump operation of the at least first cylinder.
28

7. A motor vehicle as set forth in claim 6, further comprising: a torque request input coupled to the body controller; and the body controller being responsive to a request for torque and an air pressure reading from the pressure sensor exceeding a boost threshold minimum for directing the opening of the controllable discharge valve to the drive train booster. 8. A motor vehicle as set forth in claim 6, further comprising a brake pedal position sensor wherein a negative load on the internal combustion engine is indicated by a brake pedal position sensor signals. 9. A vehicle comprising: an engine controller a drive train including a transmission, an engine having a plurality of cylinders, and an output shaft from the engine, the engine having one or more cylinders which can be operated as non-firing air pumps under the control of the engine controller; exhaust pipes from the cylinders; a shutter valve located in the exhaust pipe for at least one cylinder which can be diverted to operation as an air pump, the shutter valve being positionable to retard exhaust of air pumped from the cylinder; a fluid amplifier having an input communicating with the exhaust pipe between the cylinder and the shutter valve to operate as second stage high compression fluid pump; a high pressure storage tank connected to the fluid amplifier to receive compressed fluid; and a drive train booster connected to the high pressure storage tank to receive compressed fluid.
10. A motor vehicle as set forth in claim 9, further comprising: a controller area network; controller means for generating a vehicle speed signal for broadcast on the controller area network; the engine controller communicating with the controller area network for providing engine load and engine torque capacity information and for implementing engine compression braking and split mode operation of the engine during which one or more cylinders operate as non-firing air pumps; a braking system for retarding vehicle velocity including through requests for engine compression braking placed on the controller area network; a pressure sensor associated with the high pressure fluid storage tank for generating pressure signals and placing the signals on the controller area network; and the engine controller being further responsive to pressure sensor readings below the maximum allowed pressure for operating the shutter valve to cause the fluid amplifier to pump fluid into the high pressure storage tank during engine compression braking and still further responsive to pressure sensor readings below a second greater minimum threshold for initiating split mode operation of the engine and concurrently operating the shutter valve to actuate the fluid amplifier to pump fluid into the high pressure storage tank when internal combustion engine capacity is available.

11. A motor vehicle as set forth in claim 10, further comprising: a body controller connected to the controller area network for generating requests for torque from the internal combustion engine through the engine controller; a boost valve actuated by an engine controller for providing pressurized fluid from the high pressure tank to the drive train booster; and the engine controller being responsive to high transient torque requests and available pressure in the high pressure storage tank for opening the boost valve. 12. A motor vehicle as set forth in claim 11, wherein the drive train booster is a hydraulic motor coupled to drive an automatic or semi-automatic transmission. 13. A motor vehicle as set forth in claim 11, wherein the drive train booster is a hydraulic motor coupled to drive an automatic or semi-automatic transmission.
29

14. A motor vehicle as set forth in claim 11, wherein the drive train booster is a turbosupercharger. 15. A kinetic energy recovery system for a vehicle, comprising: an internal combustion engine having a plurality of combustion cylinders and exhaust ports from the combustion cylinders; a vehicle drive train connected to the internal combustion engine as prime mover for the vehicle drive train; a multi-stage air compression system; One or more cylinders of the internal combustion engine being available as a a low pressure stages in the multi-stage air compression system; a high pressure stage for the multi-stage compression system actuated by operation of the low pressure stage for pumping air; compressed air storage coupled to receive air pumped from the high pressure stage; a compressed air operated drive train booster coupled by a pressure regulating valve to the compressed air storage; a controller area network; sensors distributed about the vehicle providing vehicle information for distribution on the controller area network; and a body controller and an engine controller coupled to receive information on the controller area network and responsive thereto for coordinating operation of the multi-stage air compression system, the compressed air storage and the drive train booster.

**************

30

VARIABLE VALVE TIMING (VVT)

ABSTRACT A variable valve timing apparatus is employed in an engine that includes a crankshaft, an intake camshaft for driving intake valves, an exhaust camshaft for driving exhaust valves, and a transmission for transmitting rotation between the crankshaft, the intake camshaft, and the exhaust camshaft. The variable valve timing apparatus varies the valve timing of the intake valves or the exhaust valves. A first actuator is incorporated in the transmission to adjust the rotational phase of the intake camshaft or the exhaust camshaft relative to the crankshaft. A second actuator is arranged on the intake camshaft or the exhaust camshaft to adjust the valve lift of the associated valves. The result is a compact engine that avoids interference with other parts in the engine compartment.

OBJECTIVE To provide a variable valve timing apparatus employing a phase adjustor and a lift adjustor that enables unlimited control of the valve timing without occupying additional space in the engine compartment.

31

SUMMARY

The projects relates to variable valve timing apparatuses that are employed in engines. More particularly, the present invention relates to a variable timing apparatus that includes a phase adjustor and a lift adjustor for controlling the valve timing of intake valves and exhaust valves with cams. Engine variable valve timing apparatuses control the valve timing of intake valves and exhaust valves in accordance with the operating state of the engine. A variable valve timing apparatus generally includes a timing pulley and a sprocket, which synchronously rotate a camshaft with a crankshaft. The variable valve timing apparatus includes a phase adjustor, or first actuator, arranged on one end of a camshaft 1202. FIG. 18 is a cross-sectional view taken along line 18—18 in FIG. 19, while FIG. 19 is a cross-sectional view taken along line 19—19 in FIG. 18. FIG. 20 is a cross-sectional view taken along line 20—20 in FIG. 19. A sprocket 1204, which is driven by a crankshaft (not shown), is integrally coupled with a housing 1206. A vane rotor 1208 is arranged in the center of the housing 1206 and secured to the end of the camshaft 1202 to rotate integrally with the camshaft 1202. Vanes 1210 project outward from the hub of the vane rotor 1208 to contact the inner wall of the housing 1206. Partitions 1212 project inward from the housing 1206 to contact the hub surface of the vane rotor 1208. Cavities 1214 are defined between the partitions 1212. A first pressure chamber 1216 and a second pressure chamber 1218 are defined in each cavity 1214 between each vane 1210 and the partitions 1212. Hydraulic fluid is delivered to the first and second pressure chambers 1216, 1218 to rotate the vane rotor 1208 relative to the housing 1206. As a result, the rotational phase of the vane rotor 1208 relative to the housing 1206 is adjusted. This, in turn, adjusts the rotational phase of the camshaft 2102 relative to the crankshaft and varies the valve timing of the intake valves or exhaust valves. The camshaft 1202 has a journal 1224, which is supported by a bearing 1222 formed in a cylinder head of the engine. An oil channel, which is connected with a hydraulic unit 1220, extends through the cylinder head and connects to an oil groove 1226 extending along the peripheral surface of the camshaft journal 1224. The oil groove 1226 is connected to oil conduits 1227, 1228, which extend through the camshaft 1202. The oil conduit 1228 is further connected to oil conduits 1230, 1232, which extend through the vane rotor 1208 and lead into the first pressure chambers 1216. Accordingly, hydraulic fluid is forced from the hydraulic unit 1220 to the first pressure chambers 1216 through the oil channel, the oil groove 1226 and the oil conduits 1227, 1228, 1230, 1232. A further oil channel, which is connected with the hydraulic unit 1220, extends through the cylinder head and connects to an oil groove 1236, which extends along peripheral surface of the journal 1224. The oil groove 1236 is connected to an oil conduit 1238, which extends through the camshaft 1202. The oil conduit 1238 is further connected to oil conduits 1240, 1242, 1244, which extend through the vane rotor 1208 and lead into the second pressure chambers 1218. Accordingly, hydraulic pressure is communicated between the hydraulic unit 1220 and the second pressure chambers 1218 through the oil channel, the oil groove 1236, and the oil conduits 1238, 1240, 1242, 1244.

32

In addition to the first actuator, a lift adjustor, or second actuator, employed in a variable valve timing apparatus to change the lift amount and timing of intake or exhaust valves with a three-dimensional cam, is also known in the prior art. In FIG. 21, Three-dimensional cams 1302 are arranged on a camshaft 1304. A timing pulley 1306 is arranged on one end of the camshaft 1304. The timing pulley 1306 is supported such that it slides axially along and rotates integrally with the camshaft 1304. A cylinder 1308 is arranged on one side of the timing pulley 1306. A piston 1310, secured to the end of the camshaft 1304, is fitted into the cylinder 1308. A pressure chamber 1312 is defined between one side of the piston 1310 and the inner wall of the cylinder 1308. A compressed spring 1314 is arranged between the other side of the piston 1310 and the timing pulley 1306. When the pressure in the pressure chamber 1312 is high, the piston 1310 urges the camshaft 304 against the force of the spring 1314 toward the right (as viewed in FIG. 21). When the pressure in the pressure chamber 1312 is low, the spring 1314 pushes the piston 1310 and forces the camshaft 1304 toward the left. Hydraulic fluid is delivered to the pressure chamber 1312 from an oil control valve 1318 through oil conduits 1322, 1324, which extend through a bearing 1320, oil conduits 1326,1328, which extend through the camshaft 1304, and an oil conduit 1332, which extends through a bolt 1330. The bolt 1330 fastens the piston 1310 to the camshaft 1304. A microcomputer 1316 controls the oil control valve 1318 to adjust the hydraulic pressure in the pressure chamber 1312 and change the axial position of the camshaft 1304. Accordingly, the position of contact between each threedimensional cam 1302 and the associated valve lift mechanism is adjusted to vary the opening duration of a corresponding intake valve or exhaust valve in accordance with the profile of the cam 1302. This varies the valve timing.When changing the rotational phase of a camshaft relative to a crankshaft with the prior art first actuator to vary the valve timing, the opening and closing timing of the valves are both varied in the same manner. That is, if the opening timing is advanced, the closing timing is advanced accordingly, and if the opening timing is retarded, the closing timing is retarded accordingly. On the other hand, when changing the lift amount of the valves with the prior art second actuator to vary the valve timing, the opening timing and closing timing of the valves vary inversely at the same rate. That is, if the opening timing is retarded by a certain rate, the closing timing is advanced by the same rate, and if the opening timing is advanced by a certain rate, the closing timing is retarded by the same rate. Therefore, the opening and closing timing of the valves cannot be independently varied. This limits the control of the valve timing. To solve this problem, the first actuator and the second actuator can be arranged together on a camshaft to adjust both the rotational phase of a camshaft relative to a crankshaft and the lift amount of the valves. This would reduce the limitations on the opening and closing timing control. For example, as shown in FIG. 22, which illustrates an intake camshaft 1402 and an exhaust camshaft 1404, a first actuator 1408 may be arranged on one end of the intake camshaft 1402, and a second actuator 1410 may be arranged on the other end of the intake camshaft 1402. The first actuator 1408 includes a timing sprocket 1406. However, the structure formed by installing the first actuator 1408 and the second actuator 1410 on the same intake camshaft 1402 results in a longer camshaft 1402. This would also increase the size of the engine and occupy more space in the engine compartment, and space is very limited.

33

34

35

36

37

DETAILED DESCRIPTION

A first embodiment according to the present invention will now be described with reference to FIGS. 1 to 8. In the first embodiment, a variable valve timing apparatus 10 is arranged on an intake camshaft and an exhaust camshaft of an engine. FIG. 1 shows an in-line four-cylinder gasoline engine 11 mounted in an automobile. The engine 11 includes a cylinder block 13 housing pistons 12 (only one shown), an oil pan 13a located below the cylinder block 13, and a cylinder head 14 covering the cylinder block 13. A crankshaft 15 is rotatably supported in the lower portion of the engine 11. Each piston 12 is connected to the crankshaft 15 by a connecting rod 16. The connecting rod 16 converts the reciprocal movement of the piston 12 to rotation of the crankshaft. A combustion chamber 17 is defined above the piston 12. An intake manifold 18 and an exhaust manifold 19 are connected to the combustion chamber 17. Each combustion chamber 17 and the intake manifold 18 are selectively connected to and disconnected from each other by intake valves 20. Each combustion chamber 17 and the exhaust manifold 19 are selectively connected to and disconnected from each other by exhaust valves 21. An intake camshaft 22 and a parallel exhaust camshaft 23 extend through the cylinder head 14. The intake camshaft 22 is supported such that it is rotatable, though axially fixed, in the cylinder head 14. The exhaust camshaft 23 is supported such that it is rotatable and axially movable in the cylinder head 14. A phase adjustor, or first actuator 24, including an intake timing pulley 24a, is arranged on one end of the camshaft 22. The first actuator 24 rotates the intake camshaft 22 relative to the timing pulley 24a and adjusts the rotational phase of the intake camshaft 22 relative to the crankshaft 15. A lift adjustor, or second actuator 25, including an exhaust timing pulley 25a, is arranged on an end of the exhaust camshaft 23 that corresponds with the first actuator 24. The second actuator 25 moves the exhaust camshaft 23 axially to adjust the lift amount and opening duration of the exhaust valves 21. The intake timing pulley 24a and the exhaust timing pulley 25 are connected to a crank timing pulley 15a, which is secured to a crankshaft 15, by a timing belt 26. The timing belt 26 transmits the rotation of the crankshaft 15, serving as a drive shaft, to the intake camshaft 22 and the exhaust camshaft 23, which serve as driven shafts. Thus, the intake camshaft 22 and the exhaust camshaft 23 are rotated synchronously with the crankshaft 25. An intake cam 27 is arranged on the intake camshaft 22 in correspondence with each intake valve 20. Each intake cam 27 contacts the top of the associated intake valve 20. An exhaust cam 28 is arranged on the exhaust camshaft 23 in correspondence with each exhaust valve 21. Each exhaust cam 28 contacts the top of the associated exhaust valve 21. Rotation of the intake camshaft 22 opens and closes the intake valves 20 with the associated intake cams 27, while rotation of the exhaust camshaft 23 opens and closes the exhaust valves 21 with the associated exhaust cams 28.The profiles of the intake cams 27 do not very in the axial direction of the intake camshaft 22. However, as shown in FIG. 2, the profiles of the exhaust cams 28 vary continuously in the axial direction of the exhaust camshaft 23. Accordingly, each exhaust cam 27 functions as a three dimensional cam.
38

Movement of the exhaust camshaft 23 in the direction of arrow A, as viewed in FIGS. 1 and 2, causes each exhaust cam 27 to gradually increase the lift amount of the associated exhaust valve 21. This gradually advances the opening timing of the exhaust valves 21 and retards the closing timing of the exhaust valves 21. Thus, the opening duration of the exhaust valves 21 gradually increases. Movement of the exhaust camshaft 23 in the direction opposite to that indicated by arrow A causes each exhaust cam 28 to gradually decrease the lift amount of the associated exhaust valves 21. This gradually retards the opening timing of the exhaust valves 21 and advances the closing timing of the exhaust valves 21. Thus, the opening duration of the exhaust valve 21 gradually decreases. Accordingly, axial movement of the exhaust camshaft 23 adjusts the lift amount and opening duration of the exhaust valves 21. The first actuator 24 and its hydraulic drive structure will now be described in detail with reference to FIGS. 3 to 6. As shown in FIG. 3, the intake camshaft 22 has a journal 22a. The cylinder head 14 has a bearing 14a and a bearing cap 30. The journal 22a is supported between the bearing 14a and the bearing cap 30 such that the intake camshaft 22 is rotatable. A vane rotor 34 is fastened to one end of the intake camshaft 22 by a bolt 32. A knock pin (not shown) fixes the vane rotor 34 to the intake camshaft 22. This rotates the vane rotor 34 integrally with the intake camshaft 22. Vanes 36 extend from the vane rotor 34. The intake timing pulley 24a, which is arranged on the end of the intake camshaft 22 and rotatable relative to the intake camshaft 22, has a plurality of outer teeth 24b. An end plate 38, a housing body 40, and a cover 42, which define a housing, are fastened to the intake timing pulley 24a by a bolt 44 to rotate integrally with the intake timing pulley 24a. The cover 42 covers the housing body 40 with the vane rotor 34 accommodated therein. A plurality of projections 46 project from the inner wall of the housing body 40. A bore 48 extends in the axial direction of the intake camshaft 22 in one of the vanes 36. A movable lock pin 50 is accommodated in the bore 48. The lock pin 50 has a hole 50a in which a spring 54 is retained to urge the lock pin 50 toward the end plate 38. A socket 52 is provided in the end plate 38. When the lock pin 50 is aligned with the socket 52, the spring 54 forces the lock pin 73 to enter the socket 52. In this state, the end plate 38 and the vane rotor 34 are locked to each other such that their relative positions are fixed. This prohibits relative rotation between the housing body 40 and the vane rotor 34 and rotates the intake camshaft 22 integrally with the intake timing pulley 24a. An oil groove 56 extends along the front surface of the vane rotor 34. The oil groove 56 connects the lock pin bore 48 with an accurate opening 58, which extends through the cover 42. The oil groove 56 and the accurate opening 58 function to externally discharge air or oil that resides between the cover 42 and the lock pin 50 in the bore 48. As shown in FIG. 4, a cylindrical hub 60 is provided at the central portion of the vane rotor 34. Equally spaced vanes 36 extend radially from the hub 60. For example, four vanes 36, spaced 90 degrees apart from one another, extend from the hub 60 in the preferred and illustrated embodiment. Four projections 46, equally spaced like the vanes 36, project from the inner wall of the housing body 40. A cavity 62 is defined between each pair of adjacent projections 46. One of the vanes 36 extends into each cavity 62. Each vane 36 contacts the inner wall of the housing body 40 in the associated cavity 62. Each projection 46 contacts the cylindrical surface of the
39

hub 60. A first pressure chamber 64 is defined on one side of the vane 36 and a second pressure chamber 66 is defined on the other side of the vane 36 in each cavity 62. The vanes 36 are movable between the associated pair of projections 46. Therefore, contact between the vanes 36 and the associated projections 46 restricts the rotation of the vane rotor 34 relative to the housing body 40 between two positions. In other words, rotation of the vane rotor 34 relative to the housing body 40 is restricted to a range defined between the two positions. The arrow in FIG. 4 shows the rotating direction of the intake timing pulley 24a. Each second pressure chamber 66 is located on the leading side of the associated vane 36, while each first pressure chamber 64 is located on the trailing side of the associated vane 36. The rotating direction corresponds to an advancement direction for advancing the valve timing. The direction opposite of the rotating direction corresponds to a retardation direction for retarding the valve timing. Hydraulic oil is forced into the first pressure chambers 64 to advance the valve timing, while hydraulic oil is forced into the second pressure chambers 66 to retard the valve timing. A vane groove 68 extends in the axial direction along the outer surface of each vane 36. Likewise, a projection groove 70 extends along the inner surface of each projection 46. A seal member 72 and a leaf spring 74 for urging the seal member 72 radially outward are arranged in each vane groove 68. In the same manner, a seal member 76 and a leaf spring 78 for urging the seal member 76 radially inward are arranged in each projection groove 70. The operation of the lock pin 50 will now be described with reference to FIGS. 5 and 6. FIG. 5 shows the vane rotor 34 at the most retarded position, in which each vane 36 is abutted against the associated retarding side projection 46. In this state, the lock pin 50 is misaligned with the socket 50. That is, the distal end 50b of the lock pin 50 is located outside of the socket 52. The hydraulic pressure in the first pressure chambers 64 is null or insufficient when starting the engine 11 or before an electronic control unit (ECU) 180 commences hydraulic pressure control. In this state, cranking of the engine 11 produces counter torque, which rotates the vane rotor 34 relative to the housing body 40 in the advancement direction. Thus, the lock pin 50 is moved until it aligns and enters the socket 52 as shown in FIG. 6. This prohibits relative rotation between the vane rotor 34 and the housing body 40. In other words, the vane rotor 34 and the housing body 40 rotate integrally with each other during cranking. As shown in FIGS. 5 and 6, an oil conduit 80 extends through the vane 36 from the associated second pressure chamber 66 to an annular space 82 defined in the bore 48. The hydraulic pressure in the annular space 82 is increased through the oil conduit 80 to move the lock pin 50 out of the socket 52 against the urging force of the spring 54 to release the lock pin 50. A further oil conduit 84 extends through the vane 36 from the associated first pressure chamber 64 to provide the socket 52 with hydraulic pressure when the lock pin 50 is released from the socket 52. This maintains the lock pin 50 in the released state. Relative rotation between the housing body 40 and the vane rotor 34 is permitted when the lock pin 50 is released. In this state, the rotational phase of the vane rotor 34 relative to the housing body 40 is adjusted in accordance with the hydraulic pressure of the first and second pressure chambers 64, 66. A structure for delivering hydraulic oil to the first and second pressure chambers 64, 66 will now be described with reference to FIG. 3. A first oil conduit 86 and a second oil conduit 86
40

extend through the cylinder head 14. The first oil conduit 86 is connected to an oil conduit 94, which extends through the intake camshaft 22, by an oil groove 90, which extends along the peripheral surface of the intake camshaft 22, and an oil hole 92, which extends through the journal 22a. The oil conduit 94 leads into an annular space 96 defined in the vane rotor hub 60. Four oil conduits 98 extend radially from the annular space 96. Each oil conduit 98 is connected to one of the first chambers 64. Thus, the hydraulic oil delivered to the annular space 96 is sent into the first pressure chambers 64 through the associated oil conduits 98. The second oil conduit 88 is connected with an oil groove 100, which extends along the peripheral surface of the intake camshaft 22. The intake camshaft 22 has an oil hole 102, an oil conduit 104, and oil hole 106, and an oil groove 108. The oil groove 108 is connected with oil notches 110, which are formed in the end face of the intake timing pulley 24a. As shown in FIGS. 3 and 4, four oil holes 112 extend through the end plate 38 to open at a location near the projections 46, respectively. Each oil hole 112 is connected with one of the oil notches 110 and leads into a corresponding second pressure chamber 66. Thus, the hydraulic oil in the oil notches 110 is delivered to the second pressure chamber 66 through the oil hole 112. The first oil conduit 86, the oil groove 90, the oil hole 92, the oil conduit 94, the annular space 96, and the oil holes 98 define a first oil passage P1 for delivering hydraulic oil to the first pressure chambers 64. The second oil conduit 88, the oil groove 102, the oil conduit 104, the oil hole 106, the oil groove 108, the oil notches 110, and the oil holes 112 define a second oil passage P2 for delivering hydraulic oil to the second pressure chambers 66. The ECU 180 drives a first oil control valve 114 to control the flows of hydraulic oil to and the pressures of the first and second pressure chambers 64, 66 through the associated first and second oil passages P1, P2. The vane 36 that has the lock pin bore 48 has an oil conduit 84, as shown in FIGS. 4 and 5. The oil conduit 84 connects the associated first pressure chamber 64 with the socket 52 to communicate the hydraulic pressure of the first pressure chamber 64 to the socket 52. An annular oil space 82 is also defined in the lock pin bore 48 between the lock pin 50 and the vane 36. As shown in FIGS. 4 and 5, the annular oil space 82 is connected to the associated second pressure chamber 66 through an oil conduit 80. Thus, the hydraulic pressure of the second pressure chamber 66 is communicated to the annular oil space 82. The first oil control valve 114 includes a casing 116. The casing 116 has a first supply/discharge port 118, a second supply/discharge port 120, a first discharge port 122, a second discharge port 124, and a supply port 126. The first supply/discharge port 118 is connected to the first oil passage P1, while the second supply/discharge port 120 is connected to the second oil passage P2. The supply port 126 is connected to a supply channel 128, through which hydraulic oil is delivered by an oil pump P. The first and second discharge ports 122, 124 are connected to a discharge channel 130. A spool 138 having four valve elements 132 is accommodated in the casing 116. A coil spring 134 and an electromagnetic solenoid 136 urge the spool 138 in opposite directions, respectively. When the electromagnetic solenoid 136 is de-excited, the spool 138 is moved to one side of the casing 116 (to the right side as viewed in FIG. 3) by the force of the coil spring 134. This connects the first supply/discharge port 118 to the first discharge port 122 and the second supply/discharge port 120 to the supply port 126. In this state, the hydraulic oil contained in
41

the oil pan 13ais sent to the second pressure chambers 66 through the supply channel 128, the first oil control valve 114, and the second oil passage P2. In addition, the hydraulic oil in the first pressure chambers 64 is returned to the oil pan 13a through the first oil passage P1, the first oil control valve 114, and the discharge channel 130. As a result, the vane rotor 34 and the intake camshaft 22 rotate relative to the timing pulley 24a in a direction opposite to the rotating direction of the timing pulley 24a. Thus, the intake camshaft 22 is retarded. When the electromagnetic solenoid 136 is excited, the spool 138 is moved to the other side of the casing 116 (to the left side as viewed in FIG. 3), countering the force of the coil spring 134. This connects the second supply/discharge port 120 to the second discharge port 124 and the first supply/ discharge port 118 to the supply port 126. In this state, the hydraulic oil contained in the oil pan 13a is sent to the first pressure chambers 64 through the supply channel 128, the first oil control valve 114, and the first oil passage P1. In addition, the hydraulic oil in the second pressure chambers 66 is returned to the oil pan 13athrough the second oil passage P1, the first oil control valve 114, and the discharge channel 130. As a result, the vane rotor 34 and the intake camshaft 22 rotate relative to the timing pulley 24a in the rotating direction of the timing pulley 24a. Thus, the intake camshaft 22 is advanced. For example, the intake camshaft 22 may be advanced from the state shown in FIG. 4 to the state shown in FIG. 7. By further controlling the current fed to the electromagnetic solenoid 136 to arrange the spool 138 at an intermediate position in the casing 116, the first and second supply/ discharge ports 118, 120 are closed. Thus, the flow of hydraulic oil through each supply/discharge port 118, 120 is prohibited. In this state, hydraulic oil is neither supplied to nor discharged from the first and second pressure chambers 64, 66. This holds the hydraulic oil residing in each pressure chamber 64, 65. Thus, the intake camshaft 22 is rotated by the crankshaft 15 with the vane rotor 34 and the intake camshaft 22 locked to each other in a fixed relationship, for example, in the position shown in FIG. 4 or that of FIG. 7. The intake camshaft 22 is normally retarded to retard the valve timing of the intake valves 20 when the engine 11 is running in a low speed range and when the engine 11 is running in a high speed range with a high load applied. This stabilizes operation of the engine 11 by decreasing the valve overlap (the time during which the intake valves 20 and exhaust valves 21 are both opened) when the engine 11 is running in the low speed range. Retardation of the closing timing of the intake valves 20 when the engine 11 is running in a high speed range with a high load applied improves the intake efliciency of the air-fuel mixture drawn into each combustion chamber 17. Furthermore, the intake camshaft 22 is normally advanced to advance the valve timing of the intake valves 20 when the engine 11 is running in a low or intermediate load state. Advancement of the valve timing of the intake valves 20 increases the valve overlap and reduces pumping loss, which in turn, improves fuel efficiency. The second actuator 25 and its hydraulic drive structure will now be described in detail with reference to FIG. 8. As shown in FIG. 8, the second actuator 25 includes the exhaust timing pulley 25a. The exhaust timing pulley 25 has a sleeve 151, through which the exhaust camshaft 23 extends, a circular plate 152 extending from the peripheral surface of the sleeve 151, and outer teeth 153 extending from the periphery of the circular plate 152. The bearing 14a of the cylinder head 14 rotatably supports the sleeve 151 of the exhaust timing pulley 25a. The exhaust camshaft 23 is supported such that it slides axially through the sleeve 151.

42

A pulley cover 154 is fastened to the exhaust timing pulley 25a by bolts 155. Straight inner teeth 157 extending in the axial direction of the exhaust camshaft 23 are arranged along the inner surface of the pulley cover 154 in association with the end portion of the exhaust camshaft 23.A hollow ring gear 162 is fastened to the end of the exhaust camshaft 23 by a hollow bolt 158 and a pin 159. Straight teeth 163, which mesh with the inner teeth 157 of the pulley cover 154, extend along the peripheral surface of the ring gear 162. The straight teeth 163 extend in the axial direction of the exhaust camshaft 23. Therefore, the ring gear 162 moves in the axial direction of the exhaust camshaft 23 together with the exhaust camshaft 23. In the second actuator 25, when the engine 11 rotates the crankshaft 15, the rotation of the crankshaft 15 is transmitted to the exhaust timing pulley 25a by the timing belt 26. This rotates the exhaust camshaft 23 integrally with the exhaust timing pulley 25a and drives the exhaust valves 21. Movement of the ring gear 162 toward the exhaust timing pulley 25a (in the direction indicated by arrow A in FIG. 8) integrally moves the exhaust camshaft 23 in the same direction. Each exhaust valve 21 has a cam follower 21a that follows the profile of the associated three-dimensional cam 28. When the exhaust camshaft 23 moves in the direction of arrow A, contact between each exhaust cam 28 and the cam follower 21a of the associated exhaust valve 21 increases the lift amount and the opening duration of the exhaust valve 21. In other words, the opening timing of the exhaust valves 21 is advanced, and the closing timing of the exhaust valves 21 is retarded. Movement of the ring gear 162 toward the pulley cover 154 (in the direction opposite to that indicated by arrow A in FIG. 8) integrally moves the exhaust camshaft 23 in the same direction. This causes contact between each exhaust cam 28 and the cam follower 21a of the associated exhaust valve 21 that decreases the lift amount and the opening duration of the exhaust valve 21. In other words, the opening timing of the exhaust valves 21 is retarded, and the closing timing of the exhaust valves 21 is advanced. The structure in the second actuator 25 for controlling the movement of the ring gear 162 will now be described. The ring gear 162 has a flange 162a. The peripheral surface of the flange 162 slides axially along the inner wall of the pulley cover 154 during movement of the ring gear 162. Additionally, the flange 162 serves as a partition to separate a first oil chamber 165 from a second oil chamber 166 in the pulley cover 154. A first control conduit 167, which is connected to the first oil chamber 165, and a second control conduit 168, which is connected to the second oil chamber 166, extends through the exhaust camshaft 23. The first control conduit 167 is connected to the first oil chamber 165 through the interior of the hollow bolt 158. Further, the first control conduit 167 is connected to a second oil control valve 170 through a channel extending through the cylinder head 14. The second control conduit 168 is connected to the second oil chamber 166 through an oil conduit 172 extending through the sleeve 151 of the exhaust timing pulley 25a. Further, the second control conduit 168 is connected to the second oil control valve 170 through another channel extending through the cylinder head 14. A supply channel 174 and a discharge channel 176 are connected to the second oil control valve 170. The supply channel 174 is connected to the oil pan 13a by way of the oil pump P.

43

which is also used by the first actuator 24. The discharge channel 176 is directly connected to the oil pan 13a. The second oil control valve 170 has a structure similar to that of the first oil control valve 114. More specifically, the second oil control valve 170 includes an electromagnetic solenoid 170a and ports. When the electromagnetic solenoid 170a is excited, the ports are connected to deliver the hydraulic oil in the oil pan 13a to the second oil chamber 166 through the supply channel 174, the second oil control valve 170, and the second control conduit 168. In addition, the hydraulic oil in the first oil chamber 165 is returned to the oil pan 13a through the first control conduit 167, the second oil control valve 170, and the discharge channel 176. As a result, the ring gear 162 is moved toward the first oil chamber 165 to decrease the lift amount and opening duration of the exhaust valves 21. FIG. 8 shows a minimum lift amount state. When the electromagnetic solenoid 170a is de-excited, the ports are connected to deliver the hydraulic oil in the oil pan 13a to the first oil chamber 165 through the supply channel 174, the second oil control valve 170, and the first control conduit 167. In addition, the hydraulic oil in the second oil chamber 166 is returned to the oil pan 13athrough the second control conduit 168, the second oil control valve 170, and the discharge channel 176. As a result, the ring gear 162 is moved toward the second oil chamber 166 to increase the lift amount and opening duration of the exhaust valves 21. By further controlling the current fed to the electromagnetic solenoid 170a to prohibit the flow of hydraulic oil between the ports, hydraulic oil is neither supplied to nor discharged from the first and second oil chambers 165, 166. This holds the hydraulic oil residing in each oil chamber 165,166 and locks the ring gear 162. Thus, the axial position of the ring gear 162 is fixed. The lift amount and opening duration of the exhaust valves 21 remains constant as long as the ring gear 162 is locked. As shown in FIG. 1, the first and second oil control valves 114, 170 are controlled by the ECU 180. The ECU 180 includes a central processing unit (CPU) 182, a read only memory (ROM) 183, a random access memory (RAM) 184, and a backup RAM 185. The ROM 183 stores various types of control programs and maps. The maps are referred to during execution of the control programs. The CPU 182 executes the necessary computations based on the control programs stored in the ROM 183. The RAM 184 temporarily stores the results of the computations executed by the CPU 182 and data sent from various sensors. The backup RAM 185 is a nonvolatile memory that keeps the necessary data stored when the engine 11 is not running. The CPU 182, the ROM 183, the RAM 184, and the backup RAM 185 are connected to one another by a bus 186. The bus 186 also connects the CPU 182, the ROM 183, the RAM 184, and the backup RAM 185 to an external input circuit 187 and an external output circuit 188. The external input circuit 187 is connected to an engine speed sensor, an intake pressure sensor, a throttle sensor, and other sensors (these sensors are not shown in the drawings) employed to detect the operating state of the engine 11. The external input circuit 187 is also connected to a electromagnetic crankshaft pickup 190, an electromagnetic intake camshaft pickup 192, and an electromagnetic exhaust camshaft pickup 194. The crankshaft pickup 190 detects the rotational phase and rotating speed of the crankshaft 15. The intake camshaft pickup 192 detects the rotational phase and rotating speed of the intake camshaft 22. The exhaust camshaft pickup 194 detects the rotational phase, the rotating speed, and axial position of the exhaust camshaft 23. The external output circuit 188 is connected to the first and second oil control valves 114, 170. In the first embodiment, the operation of the intake and exhaust valves 20, 21 is controlled by the ECU 180. More specifically, the ECU 180
44

controls the first oil control valve 114 when it is necessary to vary the valve timing of the intake valves 20. The first oil control valve 114 is controlled based on the signals sent from the sensors that detect the operating state of the engine 11. The ECU 180 also controls the second oil control valve 170 when the lift amount and opening duration of the exhaust valves 21 must be altered so that the engine 11 runs in an optimal manner. The ECU 180 receives signals from the crankshaft pickup 190, the intake camshaft pickup 192, and the exhaust camshaft pickup 194 to control the first and second oil control valves 114, 170. The ECU 180 obtains the rotational phase of the intake camshaft 22 relative to the crankshaft 15 based on these signals. Afterward, the ECU 180 feedback controls the first actuator 24 with the first oil control valve 114 to change the rotational phase of the intake camshaft 22 so that the valve timing of the intake valves 20 is varied to a target timing. The ECU 180 also obtains the axial position of the exhaust camshaft 23. Afterward, the ECU 180 feedback controls the second actuator 25 with the second oil control valve 170 to adjust the lift amount and opening duration of the exhaust valves 21 to a target lift amount and target opening duration. The advantages of the first embodiment will now be described. In the variable valve timing apparatus 10 according to the first embodiment, the first actuator 24, which adjusts the rotational phase of the intake camshaft 22 relative to the crankshaft 15, is incorporated in the intake timing pulley 24a. Furthermore, the second actuator 25, which adjusts the lift amount of the exhaust valves 21 with three-dimensional cams, is incorporated in the exhaust timing pulley 25a. In other words, the first and second actuators 24, 25 are arranged on different, separate camshafts. Thus, the camshaft need not be elongated. This avoids the enlargement of the engine 11. Accordingly, the engine 11 is installed in an engine compartment without occupying more space than a prior art engine. Further, the valve overlap of the intake and exhaust valves 20, 21 and the closing timing of the intake valves 20 are controlled in the same manner and without the additional limitations that result when the first and second actuators 24, 25 are incorporated on the same camshaft. For example, the closing timing of the intake valves 20 is varied by the first actuator 24, which is arranged on the intake camshaft 22, in accordance with the operating state of the engine 11. The valve overlap is also adjusted by cooperation between the first actuator 24 and the second actuator 25, which is arranged on the exhaust camshaft 23, in accordance with the operating state of the engine 11. Additionally, since the two actuators 24, 25 are arranged on different shafts, neither the intake camshaft 22 or the exhaust camshaft 23 is required to support more than one actuator. Therefore, neither shaft is excessively heavy. Thus, the occurrence of problems concerning the durability of the journals supporting the shafts are avoided. A second embodiment according to the present invention will now be described with reference to FIG. 9. The second embodiment differs from the first embodiment in that a lift adjustor, or second actuator 225, is incorporated in a timing pulley 225a of an intake camshaft 222 to adjust the lift amount of intake valves 220. Furthermore, a phase adjustor, or first actuator 224, is incorporated in a timing pulley 224a of an exhaust camshaft 223 to change the rotational phase of the exhaust camshaft 223 relative to a crankshaft 215. The intake camshaft 222, which extends through a cylinder head, is supported such that it is rotatable and axially movable (in the directions indicated by arrow B). The intake camshaft 222 includes three-dimensional cams, or intake cams 227. The exhaust camshaft 223 is
45

supported such that it is rotatable, though axially fixed, in the cylinder head. Normal exhaust cams 228 are arranged along the exhaust camshaft 223. That is, the profiles of the exhaust cams 228 do not vary in the axial direction of the exhaust camshaft 223. The crankshaft 215 is identical to that employed in the first embodiment. The axial position of the intake camshaft 222 is controlled by a second oil control valve to adjust the lift amount and opening duration of the intake valves 220 in accordance with the operating state of the engine. The rotational phase of the exhaust camshaft 223 relative to the crankshaft 215 is controlled by a first oil control valve to vary the valve timing of the exhaust valves 221 in accordance with the operating state of the engine. The second embodiment has the same advantages as the first embodiment. The cooperation between the first actuator 224, which is arranged on the exhaust camshaft 223, and the second actuator 225, which is arranged on the intake camshaft 222, adjusts the valve overlap. Furthermore, the second actuator 225 varies the closing timing of the intake valves 220. A third embodiment according to the present invention will now be described with reference to FIG. 10. The third embodiment differs from the first embodiment in that neither a first actuator nor a second actuator is incorporated in a timing pulley 323a of an exhaust camshaft 323. A phase adjustor, or first actuator 324, is incorporated in a timing pulley 324a of a crankshaft 315. A lift adjustor, or second actuator 325, is incorporated in a timing pulley 325a of an intake camshaft 322. The intake camshaft 322, which extends through a cylinder head, is supported such that it is rotatable and axially movable (in the directions indicated by arrow C). The intake camshaft 322 includes three-dimensional intake cams 327. The exhaust camshaft 323 is supported such that it is rotatable, though axially fixed, in the cylinder head. Normal exhaust cams 328 are arranged along the exhaust camshaft 323. That is, the profiles of the exhaust cams 328 do not vary in the axial direction of the exhaust camshaft 323. The crankshaft 315 is supported such that it is rotatable, though axially fixed. The axial position of the intake camshaft 322 is controlled by a second oil control valve to adjust the lift amount and opening duration of the intake valves 320 in accordance with the operating state of the engine. The rotational phase of the crankshaft 315 relative to the intake camshaft 322 and the exhaust camshaft 323 is controlled by a first oil control valve to vary the valve timing of the intake and exhaust valves 320, 321 in accordance with the operating state of the engine. The third embodiment has the same advantages as the first embodiment. Additionally, the cooperation between the first actuator 324, which is incorporated in the crank timing pulley 324a, and the second actuator 325, which is incorporated in the intake timing pulley 324a, varies the closing timing of the intake valves 320 and the valve overlap. A fourth embodiment according to the present invention will now be described with reference to FIG. 11. The fourth embodiment differs from the first embodiment in that neither a first actuator nor a second actuator is incorporated in a timing pulley 422 of an intake camshaft 422. A phase adjustor, or first actuator 424, is incorporated in a timing pulley 424a of a crankshaft 415. In the same manner as the first embodiment, a lift adjustor, or second actuator 425, is incorporated in a timing pulley 425a of an exhaust camshaft 422, which has three46

dimensional cams 428. Like the first embodiment, the profiles of the intake cams 427 do not vary in the axial direction of the intake camshaft 422. The axial position of the exhaust camshaft 423 (the movement indicated by arrow D) is controlled by a second oil control valve to adjust the lift amount and opening duration of exhaust valves 421 in accordance with the operating state of the engine. The rotational phase of the crankshaft 415 relative to the intake camshaft 422 and the exhaust camshaft 423 is controlled by a first oil control valve to vary the valve timing of the intake and exhaust valves 420, 421 in accordance with the operating state of the engine. The fourth embodiment has the same advantages as the first embodiment. Additionally, the first actuator 424 arranged on the crankshaft 415 varies the closing timing of the intake valves 420. The cooperation between the first actuator 424 and the second actuator 425, which is arranged on the exhaust camshaft 423, changes the valve overlap. A fifth embodiment according to the present invention will now be described with reference to FIG. 12. The fifth embodiment differs from the first embodiment in that a lift adjustor, or second actuator 526 is incorporated in a timing pulley 526a of an intake camshaft 522. The intake camshaft 522 has three-dimensional cams 527, and is rotatable and axially movable (in the directions indicated by arrow El). In addition, a phase adjustor, or first actuator 524, is incorporated in a timing pulley 524a of a crankshaft 515. A further second actuator 525, like that of the first embodiment, is incorporated in a timing pulley 525a of an exhaust camshaft 523, which has three-dimensional cams 528. The axial position of the exhaust camshaft 523 (the movement indicated by arrow E2) is controlled by a second oil control valve to adjust the lift amount and opening duration of exhaust valves 521 in accordance with the operating state of the engine. Furthermore, the axial position of the intake camshaft 522 is controlled by another second oil control valve to adjust the lift amount and opening duration of intake valves 520 in accordance with the operating state of the engine. The rotational phase of the crankshaft 515 relative to the intake camshaft 522 and the exhaust camshaft 523 is controlled by a first oil control valve to vary the valve timing of the intake and exhaust valves 520, 521 in accordance with the operating state of the engine. The fifth embodiment has the same advantages as the first embodiment. Additionally, the cooperation between the first actuator 524, which is incorporated in the crank timing pulley 524a, and the two second actuators 525, 526, which are incorporated in the intake and exhaust timing pulleys 525a, 526a, adjusts the valve overlap and varies the closing timing of the intake valves 420. A sixth embodiment according to the present invention will now be described with reference to FIG. 13. This embodiment employs a crankshaft identical to that of the first embodiment. An intake camshaft 622, an exhaust camshaft 623, and a crankshaft (not shown) are arranged parallel to one another. A first transmission train 690 is arranged at the left ends of the shafts (as viewed in FIG. 13). The first transmission train 690 includes a timing pulley (not shown) coupled to the crankshaft, an exhaust timing pulley 624a coupled to the exhaust camshaft 623, and a timing belt (not shown) connecting the crank timing pulley and the exhaust timing pulley 624a. The torque of the crankshaft, which is applied to the crank timing pulley, is
47

directly transmitted to the exhaust timing pulley 624a by the timing belt, but is not directly transmitted to the intake camshaft 622. A second transmission train 692 is arranged at the right ends of the shafts 622, 623. The second transmission train 692 includes an intake gear 625b, which is coupled to the intake camshaft 622, and an exhaust gear 624b, which is coupled to the exhaust camshaft 623. The exhaust and intake gears 624b, 625b mesh with each other. Thus, torque is directly transmitted from the exhaust camshaft 623 to the intake camshaft 622 by the second transmission train 692. A phase adjustor, or first actuator 624, is incorporated in the exhaust gear 624b of the second transmission train 692. A lift adjustor, or second actuator 625, is incorporated in the intake gear 625b of the second transmission train 692. The structures of the first and second actuators 624, 625 are the same as that of the first embodiment. The intake camshaft 622 has three-dimensional cams 627, and is rotatable and axially movable in a cylinder head. The exhaust camshaft 623 is supported such that it is rotatable, though axially fixed. Normal exhaust cams 628 are arranged along the exhaust camshaft 623. That is, the profiles of the exhaust cams 628 do not vary in the axial direction of the exhaust camshaft 623. The sixth embodiment has the same advantages as the first embodiment. Additionally, since the first and second actuators 624, 625 are arranged on ends of the intake and exhaust camshafts 623, 622, respectively, and the first transmission gear 690 is arranged on the other end, the length of the engine can be shortened. Thus, the sixth embodiment provides more layout space in the engine compartment, especially where the first transmission train 690 is located. This side is normally located near a suspension member 694, which includes a coil spring and a shock absorber. Accordingly, interference between the engine and parts such as the suspension member 694 is avoided. A seventh embodiment according to the present invention will now be described with reference to FIG. 14. An intake camshaft 722, an exhaust camshaft 723, and a crankshaft (not shown) are arranged parallel to one another. A first transmission train 790 is arranged at the left ends of the shafts (as viewed in FIG. 14). The first transmission train 790 includes a timing pulley (not shown) coupled to the crankshaft, an exhaust timing pulley 724a coupled to the exhaust camshaft 723, and a timing belt (not shown) connecting the crank timing pulley and the exhaust timing pulley 724a. The torque of the crankshaft, which is applied to the crank timing pulley, is directly transmitted to the exhaust timing pulley 7a by the timing belt, but is not directly transmitted to the intake camshaft 722. A second transmission train 792 is arranged at the right ends of the shafts 722, 723. The second transmission train 792 includes an intake gear 725b, which is coupled to the intake camshaft 722, and an exhaust gear 724b, which is coupled to the exhaust camshaft 723. The exhaust and intake gears 724b, 725b mesh with each other. Thus, torque is directly transmitted from the exhaust camshaft 723 to the intake camshaft 722 by the second transmission train 792. In the same manner as the sixth embodiment, a phase adjustor, or first actuator 724, is incorporated in the exhaust gear 724b of the second transmission train 792. The seventh embodiment differs from the sixth embodiment in that a lift adjustor, or second actuator 725, is arranged on the intake camshaft 722 on the end that is opposite to the second transmission train 792. The second actuator 725 is fixed to a cylinder head 714.

48

An eighth embodiment according to the present invention will now be described with reference to FIGS. 15 and 16. The structure of the variable valve timing apparatus is the same as the seventh embodiment of FIG. 14. However, the eighth embodiment employs a phase adjustor, or second actuator 825, that differs from that of the preceding embodiments. The second actuator 825 has a housing 830. A cylinder head 814 has an opening 814c to receive the housing 830. Bolts 832 fasten the housing 830 to the cylinder head 814. The housing 830 has a hollow interior that is sealed by a cover 836. The cover 836 is fastened to the housing 830 by bolts 834. A piston 838 is accommodated in the housing 830 and is movable in the axial direction of an intake camshaft 822. The piston 838 serves to partition the interior of the housing 830 into a first oil chamber 840 and a second oil chamber 842. An end of the intake camshaft 822 is rotatably supported by a bearing 846 in the central portion of the piston 833. A bolt 844 secures the end of the intake camshaft 822 to the piston 838. A cap 848 is screwed into the piston 838 to cover the bolt 844 and the bearing 846. The hydraulic pressure in the first oil chamber 840 is controlled by a second oil control valve 854 through a control conduit 850, which extends through the cylinder head 814, and a control conduit 852, which extends through the housing 830. The hydraulic pressure in the second oil chamber 842 is controlled by the second oil control valve 854 through a control conduit 856, which extends through the cylinder head 814, and a control conduit 858, which extends through the housing 830. An oil pump P supplies the second oil control valve 854 with hydraulic oil by way of supply channels 860, 862, which extend though the cylinder head 814. The cylinder head 814 has a bearing 814e to support the intake camshaft 822. The hydraulic oil is also supplied to the bearing 814e through an oil conduit 864, which extends through the bearing 814e. This lubricates the intake camshaft 822, which rotates and moves axially on the bearing 814e. A discharge channel connecting the second oil control valve 854 to an oil pan is not shown in FIG. 15. The intake camshaft 822 has three-dimensional intake cams 827. Each intake cam 827 is arranged in association with an intake valve 820 having a cam follower 820a. When hydraulic oil is sent into the first oil chamber 840 by the second oil control valve 854 and hydraulic oil is forced out of the second oil chamber 842, the piston 838 moves axially toward the second oil chamber 842, as shown in FIG. 15. The intake camshaft 822 moves integrally with the piston 838. As a result, the cam followers 820afollowing the profiles of the associated intake cams 827 increase the lift amount and opening duration of the intake valves 820. This advances the opening timing and retards the closing timing of the intake valves 820. When hydraulic oil is sent into the second oil chamber 842 by the second oil control valve 854 and hydraulic oil is sent out of the first oil chamber 840, the piston 838 moves axially toward the first oil chamber 840, as shown in FIG. 16. As a result, the cam followers 820a following the profiles of the associated intake cams 827 decrease the lift amount and opening duration of the intake valves 820. This retards the opening timing and advances the closing timing of the intake valves 820.

49

The seventh and eighth embodiments have the same advantages as the first embodiment. Additionally, since the second actuator 725 (825) and the first transmission train 790 are arranged at one end of the intake and exhaust camshafts 722 (822), 723, while the first actuator 724 is arranged on the other end, the length of the engine can be shortened. Furthermore, the second actuator 725 (825) is independent from the first and second transmission trains 790, 792. Thus, the whole second actuator 725 (825) is substantially accommodated in the cylinder head 714, as shown in FIG. 14. This provides more layout space in the engine compartment, especially near the first transmission train 790. A suspension member 794 is normally located near the first transmission train 790. Accordingly, interference between the engine and parts such as the suspension member 794 is avoided. A ninth embodiment according to the present invention will now be described with reference to FIG. 17. This embodiment differs from the above embodiments in that the first and second actuators are arranged on the same camshaft. As shown in FIG. 17, in the ninth embodiment, an intake camshaft 922, and exhaust camshaft 923 are arranged parallel to one another and transversely in an engine compartment. A crankshaft, though not shown, is also parallel to the camshafts 922, 923. The intake camshaft 922 is indirectly driven by the crankshaft. The exhaust camshaft 923 is directly driven by the crankshaft. The exhaust camshaft 923 is arranged at the front side of the vehicle, while the intake camshaft 922 is arranged at the rear side of the vehicle.

A phase actuator, or first actuator 924, is arranged on the left end of the exhaust camshaft 923 (as viewed in FIG. 17) to adjust the phase of the exhaust camshaft 923 relative to the crankshaft. A lift actuator, or second actuator 925, is arranged on the right end of the exhaust camshaft 923 (as viewed in FIG. 17) to adjust the lift amount of corresponding exhaust valves with three-dimensional exhaust cams 928. Accordingly, the first actuator 924 and the second actuator 925 are both on the same exhaust camshaft 923. Neither a first actuator nor a second actuator is arranged on the intake camshaft 922. In other words, among the two camshafts 922, 923, the first and second actuators 924, 925 are arranged on the shaft located furthest from a suspension member 994. The transmission mechanism includes a first transmission train for transmitting the rotation of the crankshaft to the exhaust camshaft 923, and a second transmission train for transmitting the rotation of the exhaust camshaft 923 to the intake camshaft 922. The first train includes a crank timing pulley (not shown), a timing belt (not shown), and an exhaust timing pulley 924a, which is coupled to one end of the exhaust camshaft 923. The second train includes an exhaust cam gear 925b and an intake cam gear 926b. The first actuator 924 is incorporated in the timing pulley 924a, while the second actuator 925 is incorporated in the gear 925b. The advantages of the ninth embodiment will now be described. The suspension member 994 often limits the layout of an engine. However, an engine employing a variable valve timing apparatus according to the ninth embodiment has the first and second actuators 924, 925 arranged on the exhaust camshaft 923, which is located farther from the suspension member 994. Therefore, although the first and second actuators 924, 925 are arranged on the same camshaft, unlike the preceding embodiments, the engine is installed without interference with

50

the suspension member 994. Accordingly, the engine is installed in the engine compartment with fewer limitations on its location. Furthermore, the first and second actuators 924, 925 are both arranged on the same shaft (exhaust camshaft 923). Thus, the valve timing is varied more easily in comparison with an apparatus having the first and second actuators 924, 925 arranged on different shafts, like in the preceding embodiments. It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. For example, the present invention may be embodied as described below. The first actuator in each of the above embodiments employs a vane type rotor. However, a helical spline type rotor may be employed in lieu of the vane type rotor. In the sixth and seventh embodiments, the second actuators 625, 725 are arranged on the intake camshafts 622, 722, respectively, while the first actuators 624, 724 are arranged on the exhaust camshafts 623, 723, respectively. Instead, the first actuators 624, 724 may be arranged on intake camshafts 622, 722, respectively, and the second actuators 625, 725 may be arranged on the exhaust camshafts 623, 723, respectively. In the ninth embodiment, the intake camshaft 922 is located closer to the suspension member 994. Thus, the first and second actuators 924, 925 are both arranged on the exhaust camshaft 923. However, if the exhaust camshaft 923 is arranged closer to the suspension member 994 or if the exhaust camshaft 923 interferes with other equipment in the engine compartment, the first and second actuators 924, 925 may both be arranged on the intake camshaft 922. In the ninth embodiment, the first actuator 924 is incorporated in the exhaust timing pulley 924a, and the second actuator 925 is incorporated in the exhaust cam gear 925b. However, the first actuator 924 may be incorporated in the exhaust cam gear 925 and the second actuator 925 may be incorporated in the exhaust timing pulley 924a. In the ninth embodiment, the valve transmission formed by the first transmission train, which includes the crank timing pulley, the timing belt, and the exhaust timing pulley 924a, and the second transmission train, which includes the exhaust and intake cam gears 925b, 926b. However, the valve transmission may be a simple structure, which only includes a crank timing pulley, a timing belt, an exhaust timing pulley, and an intake timing pulley, like the valve transmission of FIG. 1. In each of the above embodiments, torque is transmitted from the crankshaft by timing belts and timing pulleys. However, other elements may be used to transmit the torque. For example, timing chains and timing sprockets or timing gears may be employed. In each of the above embodiments, three-dimensional cams (FIG. 2) are employed to change the lift amount and opening duration of the corresponding valves when driven by a second actuator. However, three-dimensional cams that have profiles for changing the opening duration of the valves, but not the lift amount, may be employed instead. Further, threedimensional cams that have profiles for changing only the closing valve timing or only the opening valve timing may also be employed.

51

In the first, second, sixth, seventh, and ninth embodiments, another first actuator may be arranged on the crankshaft. In this case, the additional first actuator facilitates valve timing control. CONCLUSION 1. A variable valve timing apparatus employed in an engine to vary the valve timing of intake valves or exhaust valves, wherein the engine includes a crankshaft, an intake camshaft for driving the intake valves, an exhaust camshaft for driving the exhaust valves, and a transmission for transmitting rotation between the crankshaft, the intake camshaft, and the exhaust camshaft, wherein the variable valve timing apparatus comprises: a first actuator arranged on only one of the intake camshaft and the exhaust camshaft, wherein the first actuator only adjusts the rotational phase of the camshaft on which the first actuator is arranged relative to the crankshaft; and a second actuator arranged on only the other of the intake camshaft and the exhaust camshaft, wherein the second actuator only adjusts the axial position of the other of the intake camshaft and the exhaust camshaft to adjust the valve lift of the valves driven by the camshaft on which the second actuator is arranged. 2. The variable valve timing apparatus according to claim 1, wherein the transmission includes a timing belt for transmitting the torque of the crankshaft to the intake camshaft and the exhaust camshaft. 3. The variable valve timing apparatus according to claim 1, wherein the transmission includes: a first transmission train for transmitting the torque of the crankshaft to the intake camshaft or the exhaust camshaft, the first transmission train being formed by a combination of a timing belt and timing pulley; and a second transmission train for transmitting torque between the intake camshaft and the exhaust camshaft, the second transmission train being formed by timing gears. 4. The variable valve timing apparatus according to claim 1, wherein the first actuator is arranged on the intake camshaft and the second actuator is arranged on the exhaust camshaft. 5. The variable valve timing apparatus according to claim 1, wherein the first actuator is arranged on the exhaust camshaft and the second actuator is arranged on the intake camshaft. 6. The variable valve timing apparatus according to claim 3, wherein the crankshaft, the intake camshaft, and the exhaust camshaft are parallel to one another, each shaft having a first end and an opposite second end, wherein the first transmission train is arranged at the first ends of the shafts, and the second transmission train is arranged at the second ends of the shafts. 7. The variable valve timing apparatus according to claim 6, wherein each of the first and second actuator is incorporated in a separate timing gear of the second train transmission and each actuator is arranged on a different one of the camshafts. 8. The variable valve timing apparatus according to claim 1, wherein the engine is installed in an automobile. 9. An engine installed in an automobile, wherein the engine comprises: a crankshaft; intake valves; an intake camshaft for driving the intake valves; exhaust valves; an exhaust camshaft
52

for driving the exhaust valves, the crankshaft, the intake camshaft, and the exhaust camshaft being parallel to one another; a transmission for transmitting rotation between the crankshaft, the intake camshaft, and the exhaust camshaft, wherein the valve timing of the intake valves or the exhaust valves is variable; a first actuator arranged on only one of the intake camshaft and the exhaust camshaft, wherein the first actuator only adjusts the rotational phase of the camshaft on which the first actuator is arranged relative to the crankshaft; and a second actuator arranged on only the other of the intake camshaft and the exhaust camshaft, wherein the second actuator only adjusts the axial position of the camshaft on which it is arranged, and wherein the camshaft that is moved axially by the second actuator includes threedimensional cams to adjust the lift amount of the corresponding valves in accordance with axial movement of the camshaft. 10. The engine according to claim 9, wherein the automobile has an engine compartment and a suspension member extending into the engine compartment, and wherein the first and second actuators are arranged on a camshaft that is furthest from the suspension member. 11. The engine according to claim 9, wherein the transmission includes a timing belt for transmitting the torque of the crankshaft to the intake camshaft and the exhaust camshaft. 12. The engine according to claim 9, wherein the transmission includes: a first transmission train for transmitting the torque of the crankshaft to the intake camshaft or the exhaust camshaft, the first transmission train being formed by a combination of a timing belt and a timing pulley; and a second transmission train for transmitting torque between the intake camshaft and the exhaust camshaft, the second transmission train being formed by timing gears. 13. The engine according to claim 9, wherein the first actuator is arranged on the intake camshaft and the second actuator is arranged on the exhaust camshaft. 14. The engine according to claim 9, wherein the first actuator is arranged on the exhaust camshaft and the second actuator is arranged on the intake camshaft.

**************

53

VARIABLE GEOMETRY INTAKE MANIFOLD

ABSTRACT A variable geometry intake manifold characterized by a variable cross-section bladder disposed within the engine's intake manifold. The degree of inflation of the bladder, and consequently the degree of occlusion of the crosssectional flow path available for the fuel/air mixture within the manifold, is controlled by a pressure or vacuum device connected to a control unit. The control unit is adapted to receive status signals relating to the engine temperature, the throttle conditions, the engine speed in revolutions per minute (RPM) and manifold vacuum. These signals are processed by the control unit and result in various signals being delivered to the pressure-vacuum providing mechanisms which modify the degree of inflation of the bladder in accordance with the parameter status conditions.

OBJECTIVES 1. It is a primary objective to provide a method for maintaining maximum vaporization of the fuel/air mixture and the delivery speed in response to a plurality of engine parameters. 2. To provide a device which is easily adapted to existing engines for maximizing their fuel usage efficiency. 3. To increase the available power output of an engine by decreasing reversion into the intake manifold thereby avoiding dilution of the fuel charge, and also being fully controllable regardless of the vacuum within the intake manifold. 4. To provide a variable control mechanism. which can be modified to adapt to specified conditions, for controlling the fuel utilization optimization components.

54

SUMMARY

The project relates to internal combustion engines and more particularly to devices for modifying and improving the delivery of the fuel/air mixture to the combustion chambers of cylinders. In recent times much attention has been focused on maximizing the efficiency of internal combustion engines in regard to the rapid decline of fossil fuel resources. Improvements have been made in the aerodynamic design of automobiles, the lessening of the total weight and also in the field of improving the engine design itself. One of the areas which has been explored in improving the efficiency of engine performance is related to the fuel/air mixture delivery systems. Since a mixture of fuel and air is delivered into the combustion chamber, it is desirable to optimize the mixture composition and the efficiency of delivery to provide for most efficient burning in the combustion chamber. Generally, as is well known in the art, intake manifolds for passenger cars and commercial vehicles such as racing cars, are made of either cast aluminum or built up of aluminum tubing. Thus the cross-sectional areas of these intake manifolds are essentially constant and generally invariable under all engine operating conditions. The fixed cross-sectional area of such manifolds contributes to inefficient engine operation and the concomitant pollution from exhaust emissions, such as carbon monoxide, carbon dioxide, oxides of nitrogen, sulphur dioxide, and various hydrocarbons. Heretofore a wide variety of intake manifolds have been proposed and implemented for internal combustion engines A variable intake manifold system for maintaining proper vaporization of the fuel/air mixture and the velocity of delivery of the mixture to an internal combustion engine cylinder by way of modifying a crosssectional flow-path of the fuel/air mixture from the throttle body to the cylinder. The system includes a variable cross-section bladder extending along a substantial portion of the intake manifold (and the cylinder port if desired). The degree of inflation of the bladder, and consequently the degree of occlusion of the cross-sectional flow path available for the fuel/air mixture within the manifold, is controlled by a pressure or vacuum sensitive device connected to a control unit. The control unit is designed to receive status signals relating to the engine temperature, the throttle position, the engine speed in revolutions per minute (RPM) and manifold vacuum. These signals are processed by the control board and result in specific signals being delivered to the pressure providing mechanisms which modify the degree of inflation of the bladder in accordance with the parameter status conditions. ADVANTAGES 1. An advantage of this apparatus is that it permits optimal modification of the flowpath in response to a plurality of engine parameters, in particular, temperature, throttle position, RPM's and vacuum, resulting in greater engine efficiency and power. 2. It may be installed in the form of a self-sufficient module on existing engines.

55

3. The control board may be reprogrammed or replaced with a different control board in the event that the user wishes to utilize different or a greater number of engine parameters to modify the flow path . 4. Exhaust emissions of the engine are reduced since the fuel-air mixture is optimized over a large range of conditions. DETAILED DESCRIPTION
The preferred embodiment of the present invention is a variable intake manifold system for varying the cross sectional flow path in the intake manifold of an internal combustion engine in a manner designed to maintain optimum vaporization and delivery speed of the fuel/air mixture provided to the combustion chambers of the cylinders. The system includes a manifold module with an inflatable bladder situated therein, pressure control elements for physically controlling the degree of inflation of the bladder, and electronic control components.

56

The intake manifold module and bladder elements of the invention are illustrated in FIG. 1 as installed in the flue flow path of a typical internal combustion engine. The fuel flow path includes a carburetion element 12, an intake manifold module 13 which includes an intake manifold 14 and a bladder 16, and an intake valve 18 into the combustion chamber of cylinder 20, the compression in which is provided by a piston 22. The bladder 16 is installed within the module 13 so as to be situated in the interior of the intake manifold 14. The bladder 16 extends over a significant portion of the length of the module 13 so as to, at least partially, occlude the mixture flow path therethrough. In FIG. 1 the bladder is shown as partially inflated. At a preselected point on the intake manifold 14 the bladder is provided with a bladder connector 24 which extends through the wall of the intake manifold 14 and provides an access point for delivery and relief of pressure within the bladder 16. Air, or any other suitable fluid (gaseous or liquid) is pumped into or out of the bladder 16 through the bladder connector 24, as controlled by the control elements of the invention. The amount of fluid within bladder 16 controls the degree of inflation and therefore modifies the cross-sectional area of the flow path of the fuel/air mixture as it passes through the intake manifold 14. The modification of the cross sectional area of the flow path maintains the vaporization of the fuel/air mixture and the speed of delivery to the intake valve 18, and consequently to the combustion chamber of cylinder 20. The manner in which the inflation of the bladder 16 affects the manifold flow path is illustrated in FIGS. 2, 3, and 4. In FIG. 2 the intake manifold 4 is shown as being circular in cross section with a semi-circular cross-section bladder 16. In FIG. 3, the intake manifold 14 is shown to be triangular in cross-section with a triangular cross-section bladder 16 and in FIG. 4, the typical case with most internal combustion engines, the intake manifold 14 is

57

shown as having a rectangular cross-section, in which case a rectangular cross-section bladder 16 is utilized.

Referring now to FIG. 5, the physical operational elements of the variable intake manifold system are illustrated in schematic fashion. This figure illustrates a typical rectangular crosssection intake manifold 14 shown in cross section. A essentially rectangular crosssection bladder 16 is shown installed flush against one wall of the manifold 14 according to the preferred embodiment. The bladder 16 is connected by way of the bladder connector 24 to pressure lines 26 extending outside of the manifold 14. One branch of the pressure line 26 is connected to a fluid source may be either a pressure source or a vacuum source, depending on the preferred manner of inflating or deflating the bladder 16. In the preferred embodiment, the fluid selected is ordinary air and the fluid source 28 is a pressure source in the form of an air compressor. The air compressor 28 is connected to the pressure line 26 leading to the bladder 16 by a pressure valve 30 interposed therein. The pressure valve 30 is a variable opening valve which may be electrically controlled by the controlling mechanism of the system to allow varying amounts of pressurized air to the bladder 16. An additional branch of the pressure line 26, interposed between the pressure valve 30 and the bladder 16, extends to a bleeder valve 32. The bleeder valve 32 allows the fluid to escape from the bladder 16, thus allowing the bladder 16 to deflate. Since the bladder 16 is ordinarily selected to be somewhat elastic, the pressure created by the elasticity of the bladder 16 forces the fluid out through the bleed valve 32 and deflates the bladder 16. FIG. 5 also illustrates a vacuum sensor element 34 which is attached to the intake manifold 14. In the preferred embodiment, the vacuum sensor element 34 is a variable resistor which provides a signal which is directly proportional to the vacuum level inside the manifold 14.

58

FIG. 6 illustrates the logical and control components of the invention. A series of sensor components deliver analogs of various engine parameter status conditions to the analyzing and control components. The analog delivery components include a temperature sensor 36, a throttle status sensor 38, an engine speed (RPM) status sensor 40, and the vacuum sensor 34. In the preferred embodiment, the temperature sensing element 36 is a thermocouple type device placed in contact with the engine coolant. Since the engine coolant temperature is directly related to the temperature conditions in the cylinders, this sensor delivers information directly related to the cylinder temperature, a factor important in determining the appropriate mixture richness and delivery speed for maximum efficiency. The throttle status sensor 38 is typically a mechanical sensor attached to the throttle arm near the point where the throttle arm attaches to the carburetor. The throttle status sensor 38 senses the throttle status, such as extreme open position or extreme closed position, and relays the imformation to the analyzing and control components. The engine speed or RPM status sensor 40 is typically an electrical sensor connected to the ignition system. The information delivered by the RPM status sensor 40 is analogous to the rate at which the cylinders 20 are firing. Each of the status sensors delivers a separate analog signal to a control board 42 which includes the analyzing and control components of the invention. The control board 42 includes a plurality of electrical and electronic components for analyzing and processing the signals generated by the sensor components. The electrical power for the components on the control board 42 is delivered through a power supply input 43. Each of the sensor inputs is separately processed in the control board 42. The temperature sensor 36 delivers a temperature analog signal 44, the throttle status sensor 38 delivers a throttle status analog signal 46, the RPM status sensor 40 delivers an RPM signal 48 and the vacuum sensor 34 delivers a vacuum analog signal 50. Each of the analog signals is then analyzed and processed within the control board 42, the output of which controls the opening of the pressure valve 30 and the bleeder valve 32. The temperature analog signal, upon entering the control board 40, passes through a threshold switch 52. Threshold switch 52 is active until the temperature signal reaches a preselected value. In the preferred embodiment it is desired that the bladder be inflated additionally when the coolant temperature is below approximately 82a C. (180° F.) so that the mixture velocity within the manifold is increased. Therefore, the threshold switch 52 remains closed and allows the passage of a signal as long as the incoming temperature analog signal 44 corresponds to the coolant temperature of less than 82° C. (180° F.). From the threshold switch 52, the temperature analog signal 44 continues through a first buffer 54. The first buffer 54 is typically an operational amplifier which modifies and shapes the signal for appropriate delivery. From the first buffer 54, the signal continues to a first signal weighting network 56. The first signal weighting network 56 is illustrated as being a variable resistor. The variable resistor 56 is necessary to provide appropriate weighting of the temperature, throttle, RPM and vacuum status analog signals, 44, 46, 48, and 50 respectively, for appropriate modification of the bladder inflation in response to changes in the parameters.

59

After passing through the first variable resistor 56, the temperature analog signal 44 is delivered to a first adder element 58. The first adder 58 combines the weighted signals from each of the sensor elements and delivers an appropriate output signal to the pressure valve 30. The net result is that during low start up temperature conditions the pressure valve 30 opens and the mixture richness and velocity are increased. Then normal operating temperatures are achieved the pressure valve 30 remains unaffected by this parameter. The throttle status analog signal 46 enters the control board 42 from the throttle status sensor 38. It then passes through a differentiator 60 which weights the signal for rate of change of status as well as for actual status. After the differentiator 60 the throttle status signal 46 divides. One branch is delivered through a first inverter 62 and a second signal weighting network 64 to the first adder 58. The remainder of the signal branches through a third signal weighting network 66 and into a second adder 68. In second adder 68, it is combined with signals from other factors to generate a signal to the bleeder valve 32. First inverter 62, on the signal path for the throttle status signal 46 to first adder 58. causes the pressure delivered to the bladder to be significantly lessened when the throttle is wide open or is increasing rapidly. Concurrently, the remaining branch of the throttle status analog signal 46 is not inverted and thus delivers a signal to second adder 68 which results in more rapid deflation of the bladder 16 and thus increasing the flow path. The RPM analog signal 48 is delivered from the RPM status sensor 40 to the control board 42. Within the control board 42, it passes through a second inverter 70 and a fourth signal weighting network 72 and is delivered to first adder 58. The RPM status signal 48 is inverted with respect to increasing RPM's since it is desirable that the degree of bladder inflation be decreased as engine speed increases. The vacuum analog signal 50 is delivered from the vacuum sensor 34 into the control board 42. The vacuum analog signal 50 enters a third inverter 74 and then branches. One arm of the signal path then passes through a fourth inverter 76 and a fifth signal w eighting network 78 to enter first adder 58. The remaining branch is delivered through a sixth signal weighting network 80 to second adder 68. The net result is that a high vacuum condition, which corresponds to low engine loading, results in a doubly inverted, or original polarity signal being delivered to the first adder 58 while an inverted signal is delivered to second adder 68. The net result of this is that during vacuum conditions the bladder inflation is increased. Conversely, when the vacuum status is low, corresponding to heavy engine loading, a smaller magnitude signal is delivered to first adder 58 when a greater signal is delivered to second adder 68. This leads to decreased bladder inflation and increased mixture flow path. The net output signal of the first adder 58 is the weighted combination of the direct temperature analog signal 44 and the direct vacuum analog signal 50 with the inverted throttle status analog signal 46 and the inverted RPM analog signal 48. This net output is in the form of a pressure valve control output 82. Pressure valve control output 82 is delivered to the pressure valve 30. The pressure control output 82 modifies the degree of opening of pressure valve 30. The output of second adder 68 is the weighted combination of the direct differentiated throttle status analog signal 46 and the inverted vacuum analog signal SO. The combined output forms a bleeder valve control output 84 which is then delivered to control the degree of opening in the bleeder valve 32.
60

The present invention is installed on an engine by inserting a manifold module 13 in place of a standard intake manifold. It is also possible, although more difficult, to modify an existing manifold to mount a bladder 16 therein. At the present time, the preferred shape of the intake manifold 14 in the module 13 is a triangular cross section manifold such as is shown in FIG. 3. Alternative shapes, however, are within the scope of the invention, for example, a rectangular cross section configuration of the intake manifold 14 in module 13. The control board 42 is then mounted at some convenient position. The power supply input 43 is connected to the automobile electrical system, or if desired, to a separate power supply. The vacuum sensor 34, temperature sensor 36, throttle status sensor 38 and RPM status sensor 40 are then appropriately connected. At this point, the variable intake manifold system is ready for operation. The system responds to variations in engine parameters as shown in Table A below.

The degree of weighting of the signals for each of the parameters provided by the first through sixth signal weighting networks is determined for the conditions of the particular engine. Generally, the temperature and RPM analog signals 44 and 48, respectively, will be weighted more highly than the throttle analog signal 46 with the vacuum analog signal 50 receiving the least weighting. Those skilled in the art will be able to adjust the variable resistors or other variable signal weighting network components to optimize the response of a particular internal combustion engine. As is discussed above, various types of intake manifold configurations and corresponding bladder configurations may be utilized with the present invention. The shape is largely a matter of choice of the user. Common materials are used for the intake manifold 14 while the bladder 16 must be of a flexible, fluid-tight material which is resistant to degradation in the presence of gasoline or other fuel components. Although it is preferred that the bladder 16 be elastic, this is not a necessary restriction.

61

The pressure valve 30 and the bleeder valve 32 may be selected from any of a number of types of valves which have variable openings which may be electrically controlled. Since the bleeder valve 32 is intended to be at least partially open at all times, it must be adjusted in such a manner that it always allows some fluid flow. The fluid selected is also a matter of choice although ordinary air appears to be the most economical and is sufficient for most purposes. Various types of parameter sensors, other than those described above, may be utilized with the present invention. The control board 42 may be modified or adjusted in accordance with differing types of signals delivered. Furthermore, in the event that a user wishes to incorporate additional or different parameters than those discussed herein, this may be accomplished by modifying the sensors and the control board to incorporate such additional factors. The precise figuration of the components within the control board is also largely a matter of choice, as long as the desired net pressure valve control output 82 and the bleeder valve control output 84 are achieved. CONCLUSION 1. An inflatable bladder installed within the intake manifold so as to partially cross sectionally occlude a fuel/air mixture flow path; means for inflating and deflating the bladder so as to occlude a cross-section of said flow path; and means for controlling the inflating and deflating means in response to preselected engine parameter conditions. 2. The system of claim 1 wherein: said bladder is similar in inflated cross-section To cross-section of said intake manifold and extends along at least a portion of flow path of said manifold. 3. The system of claim 1 wherein said means for inflating and deflating includes: a valve controlled pressure supply means for delivering fluid into said bladder in order to inflate said bladder; and a valve controlled fluid outlet for allowing fluid to escape said bladder and allowing said bladder to deflate. 4. The system of claim 1 wherein said means for controlling includes: sensing means for sensing said preselected parameters and producing analog signals of said parameters; delivery means for transporting electrical signals within said variable intake manifold system; analyzing means for comparing, weighting, and combining said analog signals to produce control signals; and flow control means for receiving said control signals and modifying the inflating and deflating means in response thereto. 5. The system of claim 3 wherein the means for controlling includes: sensing means for sensing said preselected parameters and producing analog signals of said parameters; delivery means for transporting electrical signals within the system; analyzing means for comparing, weighting and combining said analog signals to produce control signals; and flow control means receiving said control signals and modifying the inflating and deflating means in response thereto.

62

6. The system of claim 5 wherein: said preselected parameters include engine temperature, throttle status, engine speed and intake manifold vacuum. 7. The system of claim 5 wherein said analyzing means comprises a control board including: separate inputs for independently receiving each of said analog signals; a first adder for combining preselected, processed analog signals into a pressure valve control output signal, which signal controls the degree of opening of said pressure valve; a second adder for combining preselected, processed analog signals into an outlet valve control output signal, which signal controls the degree of opening of said outlet valve; and separate signal processing networks for receiving each of said analog signals at said inputs, processing said signals and delivering said processed signals to said first adder and said second adder. 8. The system of claim 7 wherein: said separate signal processing networks includes signal shaping components and variable signal weighting components. 9. The system of claim 2 wherein: said intake manifold is selected to have a triangular cross-section.

**************

63

AUTOMATIC DIFFERENTIAL LOCKING SYSTEM

ABSTRACT When a working vehicle travels on a inclined ground or on an unlevelled ground, slipping causes a difference in revolution between right and left wheel impairing straight running of the vehicle.it is therefore conventional practice to equip a working vehicle such as a lawn mower or a garden tractor which needs to be run in a straight manner with a differential locking mechanism to forcibly stop the differential revolution of the wheels. If the differential lock remained on during all time then it may leave scratches on the ground. Hence an automatic differential locking system has to be designed to eliminate the above disadvantage. This system permits the differential to be locked only when the steering angle is below a predetermined value and release the lockup when the steering angle exceeds it. In this report we will be developing an automatic differential locking system for a vehicle with having a 4 wheel drive and with both front and rear wheels steerable selectively. An actuator will actuate the differential lock in response to the signal provided by the gate from the selector mechanisms and sensors.

OBJECTIVE Primary objective of the project is to provide an automatic differential locking adapted to constantly maintain the differential lockup at times of parallel steering mode for improved running performance on an inclined ground or an unlevelled surface. Another objective of the invention is to provide a working vehicle equipped with above differential locking system to be capable of reliable straight running and excellent working performance. Also it aims in providing differential locking safety mechanism to release differential locking when an excessive load is encountered, thereby to save gears and other elements of differential from damage.
64

DETAILED DESCRIPTION OF THE EMOBIMENT A Four wheel drive mower vehicle comprises of a vehicle body (V) including a frame(1) at the lower portion. The frame carries the driver’s seat (2) , a steering handle (H) and a transmission case (M) at a rear portion and an engine (E) at the front. Below the frame are the ground wheels (3) namely front drive wheels (3F) and rear drive wheels(3R).

Fig. 1

Fig. 2

Referring to fig. 3, output of the engine E is transmitted to a hydraulic step less transmission (HST) mounted in the transmission case M. The engine output then goes through a change speed operation effected by change speed pedal (9) or a decelerator motor(10) acting as automatic speed control actuator. The reduced power is applied to the mower (4) as well as respective differential (3a) and (3b) 0f the front and rear wheels, to drive the front and rear wheels and mower simultaneously.

65

Fig. 3

As shown in fig.4, the pedal (9) and an auxiliary plate (9a) are attached to the support shaft (9b) to be pivotable in the union and a link (11) is also attached to the support shaft. This link is operatively connected through a push pull rod (12) to one end of a pivot arm (13). The pivot arm has the other end connected to an automatic speed control motor (10) through a push pull rod, a first arm (10a) and a multidisc type frictional device (D). A plate member (13a) is attached to the pivot arm (13) to be pivotable in unison. The plate member (13a) defines a centrally recessed cam surface Q. cam member (14a) acting on this cam surface Q is attached to a second arm (14b) extending from the control shaft (14) of the hydraulic stepless transmission HST. The second arm 14b carries a tension spring 14c at the extreme end thereof to maintain the cam surface Q and the cam member 14a in constant engagement. Thus, the further forwardly the pedal 9 or the auxiliary plate 9a is depressed from neutral N, the faster the vehicle travels forward and the further backwardly the pedal or the auxiliary pedal 9a is depressed, the faster the vehicle travels backwards. When the driver removes his foot from the pedal 9 or the plate 9a, the second arm 14b automatically returns to an initial change speed position by a biasing force 25 of the spring 14c. since the motor 10 is connected to the pivot arm 13 through the multi plate type frictional transmission device D, the pivot arm 13 is constantly maintained pivotable by the pedal operation. Therefore the travelling speed of the vehicle is manually changeable by operating the pedal 9 even when the motor 10 is operating to effect automatic speed control.

Fig. 4

66

The change speed position of the pedal 9 and the motor 10 are detected by potentiometer R3 operable with rotation of control shafts 14 of the hydraulic stepless transmission HST, and are fed back to the control mechanism I. The front and rear wheel 3F and 3R are not only drive wheels but are steerable wheel operable by power steering. These wheels are steerable by the driver by the means of the steering handle H, by remote control such as by the means of radio signal or automatically by pre-set control parameters. The steering handle H is vertically extendeble and retractable relative to the vehicle body, and is lowered when out of use at times of remote control or automatic steering control in order to be out of the way while the vehicle is running. A steering amount of the handle H is detected by a potentiometer Ro operatively connected thereto. The mower 4 carries frame 8 having sensors 5 attached to extreme ends such that the sensor 5 is distributed in the 4 corners of the vehicle body V. the sensor 5 act as a working area detector means and detect a boundary L between an untreated area B and a treated area C which serves as a running course guide at times of automatic steering control. The working vehicle further includes a follower wheel 6A at the rear end of the vehicle body V. The follower wheel 6A constitutes a photo-interrupter type distance sensor 6 for putting out a pulse signal Po including a certain number of pulse per unit running distance. A detected running distance is used as a control parameter for initiating a turn control during automatic running of the vehicle to bring the vehicle from a completed course to a next course to run. The vehicle further carries an orientation sensor 7 comprising a geomagnetic sensor to sense geomagnetic variations in order to detect the orientation of a vehicle while running. The detected orientation is used as control parameters for maintaining the straight running of the vehicle and determining the running direction of the vehicle under remote control or automatic steering control. The front and rear wheel 3F and 3R are steerable as already noted and accordingly three steering modes are available for selection. One of them is parallel steering mode which permits the vehicle to move sideways by turning the front and rear wheel in the same direction. Another is a turn steering mode which permits the vehicle to make a small sharp turn by steering the front wheel and the rear wheel in opposite directions. The third mode is an ordinary two wheel steering mode for steering only the front wheels 3F as in the case of ordinary automobiles.

67

Fig. 5

Referring to fig. 5, the frame 1 carries double acting cylinders 15F and 15R at the front and the rear position thereof respectively. The cylinders 15F and 15R are operatively connected to the front wheels 3F and the rear wheels 3R through steering tie rods 16, respectively. The cylinders 15F and 15R are controlled by ON/OFF operation of electromagnetic valves 17F and 17R The electromagnetic valves 17F and 17R. The electromagnetic valves 17F and 17R are operated under a feedback control which brings the steering angles detected by the potentiometers R1 and R2 respectively provided for the front and rear wheels into agreement with the required steering amounts by an operation of the handle H or by radio control. The differential 3b of the rear wheel 3R is provided with a differential locking mechanism as shown in fig. 6 and 7. In fig. 6 and 7 the differential 3b is supported by a transmission case M through bearings 18. The differential 3b includes a differential gear case 19, a left differential shaft 20 and a right differential shaft 21. The differential locking mechanism F includes a differential locking sleeve 22 splined to the left differential shaft 20 inside the transmission case M to be slided axially of the left differential shaft 20. The sleeve 22 and the differential gear case 19 defines a clutch device 22k, 19k there between which is engageable to lock the differential 3b. The transmission case M carries a member 23 containing a piston 24 operatively connected to the sleeve 22 through a control arm 25. The member 23 defines an oil port 26 in communication with a hydraulic device through an electromagnetic locking valve 27. As the piston 24 is vertically moved by an ON/OFF operation of the electromagnetic valve 27, the sleeve 22 is caused by means of the control arm 25 to slide rightward or leftward along the
68

left differential shaft 20. As a result the clutch is operated to bring the differential locking mechanism F should desirably include a safety device to safeguard the gears and other parts of the differential from damage due to overloads. For this purpose the sleeve 22 is constantly biased by spring 28 towards a position to engage the clutch, and the clutch has an inclined engagement structure which comes out of engagement when acted on by a torque exceeding a predetermined value acts on the clutch, the differential locking mechanism F is released to unlock the differential. The control arm 25 has a tip end 22 abutting on the sleve 22 towards a differential lock release position. The piston 24 has a stroke allowance to carry out the differential lock release reliability in spite of wear at the tip end of the control arm 25. The member 23 contains pistons 29 at the right and left lateral sides thereof above the differential shaft 20 and 21, respectively , the piston 29 being extendible laterally outwardly of the member 23. There is provided a member 30 attached to each lateral sides of the member 23 and disposed outwardly of and opposed to the piston 29. The member 23 and member 30 have pads 31, respectively. Disk 32 are splined to bosses of the right and left differential shaft 20 and 21 outside the transmission case M, respectively, each disk 32 extending into a space between the pad 31 on the member 23 and the pad 31 on the member 30. These elements constitute hydraulic disks brakes DB. Reference number 33 in fig. 7 denotes a brake applying electromagnetic valve. The electromagnetic valves 27 and 33 are arranged longitudinally of the vehicle body. Therefore fig. 6 shows valve 27 only whereas fig. 7 shows the valve 33 only. Each of the boundary sensors 5 mounted on the frame 8 fixed to the mower 4 comprises a combination of two photosensors S. each photosensor include a light transmitter and a light receiver opposed to each other across a slit. Weather the photosensor S is on the untreated area B or on the treated area C is determined by detecting the presence or absence of lawn passing between the light emitter and light receiver . A combination of results of lawn presence or absence detection by the two photosensor S form the basis of determining the right and left position of the vehicle body with respect to the boundary L. more particularly the vehicle is judged to be travelling along the boundary when the photosensor S is disposed laterally outward of the vehicle body both detect the treated area C and the other photosensor S is detecting the untreated area B. when the right and left boundary sensors 5 at the front of the vehicle body both detect the treated area C and the running distance detected by the distance sensor 6 reaches a preset reference distance corresponding to one course, the detection is used as a control parameters for initiating a vehicle turning control to move the vehicle to a next course.

69

Fig. 6

Fig. 7

Since the lawn passes intermittently, a working site condition detection signal obtained from the photosensor S is in the form of a signal comprising of broken pulses. Therefore the signal input to the control mechanism I after being integrated by a waveform processing circuit 33 as shown in fig 8. An integration time constant of the waveform processing circuit 33 is set by the pulse signal Po output by the distance sensor 6, to be an optimal value in accordance with a travelling speed of the vehicle. The above is a digital processing function as a digital filter. Details of the control mechanism I will be described herein after with reference to circuit diagram shown in fig. 8. The control mechanism I includes a central processing unit (CPU) 34 for receiving the pulse signal Po from the distance sensor through a counter timer circuit CTC, and the working area condition signals from the photosensors S through the waveform processing circuit 33 and a parallel input port (PIO) 35. The signals from the photosensors S are processed by means of the signal from the distance sensors 6 which generates an interrupt signal at every unit distance run by the vehicle, a position of the vehicle relative to the boundary L is determined and a control signal for steering the front and rear wheels 3F and 3R is output from a parallel I/O port 35 at an output side. Similarly, the CPU 34 recieves also a signal from an operational mode selector switch SW3 and a signal from the started switch SW4 is for starting the control mechanism I. the signal from the operational mode selector switch SW3 is for selecting is for selecting one of the three modes according to which the control mechanism I is to operate. The three operational mode comprises a manual mode, a teaching mode and a playback mode. The manual mode is that in which the vehicle is steered by the driver by means of a steering handle H. In the teaching mode, the vehicle is manually driven along peripherels of the site to be treated to form the treated area C preperatory to the automatic running control, and a working range is thought to the system by sampling distances travcelled and orientation detected by the orientation sensor 7 during the drive along the peripheries. In the playback mode, the vehicle is driven under radio control or automatically travels within the working range determined through the above teaching mode. The signal output by the orientation sensor 7 si passed through a banned filter 36 and a baffer Ao , and is then fed together with the signals from the potentiometers R0-R3 to a multiplexer 37. The signals are digitalised by an A/D converter 38to be fed to the CPU 34.
70

Fig. 8

The control mechanism 1 further includes a steering mode selector switch SW1 for selecting the parallel steering mode, the turn steering mode or the two wheel steering mode at times of manual driving, and a remote control switch SW2 for switching from manual driving to remote control mode in which vehicle is controlled according to the guide signal transmitted from a signal transmitter to a receiver 39. The signal output by the receiver 39 onto a first steering mode selector channel CH2 and a third , change speed channel CH3 are converted into voltage signals by a frequency/voltage converter 40 and only the remote control switch SW2 is turned on, are coupled to the interior of the control mechanism I through analog switches Go. On the other hand when the switch SW@ is turned on output lines from the steering mode selector switch are disabled by the analog switch Go. The steering amount detected by the potentiometer Ro at times of manual control or the steering amount fed to the second channel CH2 at times of remote control is inout to the drive circuits 41F and 41R for the electromagnetic valves 17F and 17R connected to the front and rear wheels 3F and 3R. the electromagnetic valves 17 F and 17R are then driven until steering angles of the front and rear wheels 3F and 3R detected by the potentiometers R1 and R2 corresponds to the input steering amount.
71

In the case of turn steering mode the front and rear wheels 3F and 3R are steered in opposite directions. For this purpose, when in the manual mode the turn steering mode is selected by the steering mode selector switch SW1, the output signal of the potentiometer Ro which detects the steering amount of the handle H is passed through an inverting amplifier A2 to invert its polarity and is then fed to the drive circuit 41R for the electromagnetic valve connected to the rear wheels 3R. Also when the turn steering mode is selected in the remote control mode, a required steering amount signal transmitted through the second channel is passed through the inverter amplifier A2 prior to input to the electromagnetic valve drive circuit 41R. The signal sent through the third, change speed channel CH3 is passed through the analog switch Go to a drive circuit 42 for driving the automatic speed control motor 10 only when the remote control switch SW2 is turned on. Then the hydraulic stepless transmission HST is driven until the detection value of the change speed position detecting potentiometer R3 corresponds to the signal input from the third channel CH3. The electromagnetic valve 27 of the differential locking mechanism F is maintained in action to automatically lock the differential for the rear wheels 3R when the parallel steering mode is selected by the steering mode selector switch SW1, when the parallel steering mode is selected by the signal fed through the first channel CH1 at times of remote control mode, and when the vehicle is automatically controlled in the parallel steering mode by CPU 34 in response to detection of the boundary L by the boundary sensors 5. In the steering modes other than the parallel steering mode, the differential is automatically locked when the steering amount is small. To achieve this automatic differential lockup, the output of the potentiometer R1 for detecting the steering angle of the front wheels 3F is checked by comparators A1 of like construction and, when the output is within a predetermined range of voltage, a signal is sent out to turn on the electromagnetic valve 27. Thus, the differential locking mechanism F is released only when the vehicle is turned with a steering angle exceeding a predetermined value. When the electromagnetic valve 27 is turned on, oil is not supplied to the oil port 26. Therefore the differential locking mechanism F is maintained in operation by the clutch 19K, 22K maintained in engagement by the biasing force of the spring. For adjusting a position of the vehicle with respect to the boundary, the parallel steering mode is preferable which permits the vehicle to move sideways without turning since the vehicle then hardly moves zigzag and leave lawn uncut. Therefore, the detection signal from the boundary sensors S is used as control parameter for parallel steering under automatic control by CPU 34. In other words the positional adjustment is carried out by moving the vehicle sideways until the boundary sensors 5 detect the boundary L. However, when the vehicle turns inadvertently during the parallel steering mode, the vehicle cannot be brought back to face a proper direction. On such an occasion the turn steering mode utilizing orientation variations detected by the orientation sensor 7 is employed to turn the vehicle until the orientation deviation is reduced to a permissible value. After the orientation of the vehicle is adjusted, the mode is switched to the parallel steering to effect a positional ajustment on the vehicle with respect to the boundary. Thus, a suitable steering mode is automatically selected to adjust a facing direction of the vehicle and permit the vehicle to travel straight along the boundary L.

72

In FIG. 1, reference A3 denotes differential amplifiers, and reference G1 denotes three state baffers for changing the control signals for the differential locking electromagnetic valve 27, the drive circuits 41F and 41R for driving the electromagnetic valves connected to the front and rear wheels, and the drive circuit 42 for the speed control motor 10, from the manual control or the remote control to the control by the CPU 34. In the described embodiment the differential locking mechanism is provided for the rear wheels 3R, but it will be apparent that the same effect is produced by providing a differential locking for the front wheels instead. Further, in the described embodiment, in order to incorporate the safety device into the differential locking mechanism, the clutch is constantly placed in engagement by the biasing force of the spring and is released by an OFF signal sent from the electromagnetic valve 27. Where the safety device is not required, the clutch may be constantly placed in a disengaged position and be brought into engagement by an ON signal from the electromagnetic valve 27. In this case the OR gate acting as the gate means for outputting signals to the electromagnetic valve 27 in FIG. 1 may be added with an inverter. In short, it is essential to release the differential locking to permit the differential to work only when the vehicle is turned with a steering angle exceeding a predetermined value. CONCLUSION 1. An automatic differential locking system for a working vehicle having steerable front and rear wheels, comprising a differential locking mechanism situated in at least one of the front and rear wheels, selector means for selecting a steering mode of the vehicle actuator means for actuating and releasing the differential locking mechanism, and gate means for controlling the actuator means in response to a signal received from the selector means, said gate means, when the selector means is in a parallel steering mode, sending a signal to the actuator means always to actuate the differential locking mechanism, and when the selector means is in a mode other than the parallel steering mode, sending a signal to the actuator means to actuate the differential locking mechanism unless the steering amount exceeds a predetermined level. 2. An automatic differential locking system as claimed in claim 1 further comprising OR means for sending an output signal in response to a turning signal and a two-wheel steering mode signal received from the selector means steering angle detector means for detecting a steering angle of the front wheels and, when the steering angle is within a predetermined range, sending an output signal, and AND means for sending an output signal in response to the output signals received from the OR means and the steering angle detector means, said gate means being adapted to send a signal to the actuator means to actuate the differential locking mechanism in response to the signal received from the AND means. 3. An automatic differential locking system as claimed in claim 2 wherein the steering angle detector means comprises a combination of potentiometer means for detecting the steering angle and comparator means. 4. An automatic differential locking system as claimed in claim 3 wherein the comparator means includes a first and a second comparator operational amplifiers having a common input, the amplifiers being adapted to set an upper limit and a lower limit of the predetermined range of steering angle, respectively.
73

5. A working vehicle having an automatic differential locking system, comprising a vehicle body including steerable front and rear wheels, a steering mechanism for determining a steering amount for the front and rear wheels, selector means for selecting a steering mode of the vehicle, steering control means for steering the front and rear wheels in response to the steering amount determined by the steering mechanism and to the steering mode selected by the selector means, a differential locking mechanism for limiting differential revolutions of the wheels, actuator means for actuating and releasing the differential locking mechanism, and gate means for sending a control signal to the actuator means in response to a signal received from the selector means, said gate means, when the selector means is in a parallel steering mode, sending a signal to the actuator means always to actuate the differential locking mechanism, and when the selector means is in a mode other than the parallel steering mode, sending a signal to the actuator means to actuate the differential locking mechanism unless the steering amount exceeds a predetermined level. 6. A working vehicle as claimed in claim 5 further comprising receiver means mounted on the vehicle body to receive a control signal from a radio transmitter, the receiver means including a first channel and a second channel for sending signals to the gate means and the steering control means, respectively, the first channel sending a steering mode signal and the second channel sending a steering amount signal. 7. A working vehicle as claimed in claim 6 further comprising a radio control changeover switch for enabling the first and second channels, and at the same time disabling a coupling of the steering mechanism and the selector means to the steering control means and the gate means. 8. A working vehicle as claimed in claim 7 wherein the differential locking mechanism comprises a differential locking sleeve slidably mounted on a differential shaft of a differential mechanism to be engageable with a differential gear case of the differential mechanism, the differential locking sleeve being operable by the actuator means to couple with and uncouple from the differential gear case. 9. A working vehicle as claimed in claim 8 further comprising a differential locking safety device, the safety device including spring means for biasing the differential locking sleeve to a position to couple with the differential gear case, and a safety clutch for uncoupling the differential locking sleeve from the differential gear case against a biasing force of the spring means when a torque transmission between the differential locking sleeve and the differential gear case exceeds a predetermined value. 10. A working vehicle as claimed in claim 6 further comprising boundary sensor means for detecting a boundary between a treated area and an untreated area of the ground and detecting a position of the boundary, and control means for connecting the boundary sensor means to the steering control means and the actuator means, said control means being adapted to actuate the steering control means, in response to detection of the position of the boundary by the boundary sensor means, to cause a parallel movement of the vehicle toward the boundary until the boundary sensor means detects the boundary, and at the same time send a control signal to the actuator means to actuate the differential locking mechanism. 11. A working vehicle as claimed in claim 10 further comprising an orientation sensor for detecting a running orientation of the vehicle, wherein the control means is adapted to measure a deviation from a reference orientation of the orientation detected by the orientation
74

sensor, to actuate the steering control means, when the deviation exceeds a tolerance value, to turn the vehicle until the deviation is reduced to the tolerance value, and to actuate the steering control means, when the deviation is reduced to the tolerance value, to cause the parallel movement of the vehicle toward the boundary until the boundary sensor detects the boundary. 12. A working vehicle having an automatic differential locking system, comprising a vehicle body including a pair of front wheels and a pair of rear wheels steerable in a plurality of steering modes including a parallel steering mode, a steering mechanism for determining the steering amount for the front and rear wheels, selector means for selecting one of the steering modes, steering control means for steering the front and rear wheels in response to the steering amount determined by the steering mechanism and to the steering mode selected by the selector means, a differential locking mechanism for at least one of the front wheel pair and the rear wheel pair for limiting differential revolutions of the wheels, actuator means for actuating and releasing the differential locking mechanism, and gate means for sending a control signal to the actuator means in response to a signal received from the selector means, wherein the actuator means maintains the differential locking mechanism in operation in all steering modes when the steering amount is below a predetermined level, and the gate means sends a signal to the actuator means to release the differential locking mechanism only when the selector means is in a mode other than the parallel steering mode and the steering amount exceeds the predetermined level. 13. A working vehicle as claimed in claim 12 wherein the differential locking mechanism comprises a differential locking sleeve slidably mounted on a differential shaft of a differential mechanism to be engageable with a differential gear case of the differential mechanism, the differential locking sleeve being operable by the actuator means to be coupled to and uncoupled from the differential gear case. 14. A working vehicle as claimed in claim 13 wherein the actuator means comprises bias means for biasing the differential locking sleeve to a position to actuate the differential locking mechanism, and a hydraulic piston device for sliding the differential locking sleeve against a biasing force of the bias means to a position to release the differential locking mechanism 15. A working vehicle as claimed in claim 14 wherein the differential locking sleeve and the differential mechanism define there between an inclined engagement structure for interconnecting the differential locking sleeve and the differential mechanism, the inclined engagement structure being disengageable by a torque acting thereon that exceeds a value determined by the bias means. 16. A working vehicle as claimed in claim 15 wherein the bias means comprises a spring. 17. A working vehicle as claimed in claim 14 further comprising receiver means mounted on the vehicle body to receive a control signal from a radio transmitter, the receiver means including a first channel and a second channel for sending signals to the gate means and the steering control means, respectively, the first channel sending a steering mode signal and the second channel sending a steering amount signal.

**************
75

SEMI-AUTOMATIC ELECTRIC GEAR SHIFTING APPARATUS FOR A MOTORCYCLE

ABSTRACT A semi-automatic electric gear shifting apparatus for use in shifting gears in gear boxes of motorcycles and the like gear boxes wherein gears are shifted by rotating a spindle operably connected to a ratchet type gear shifting means. The said gear shifting apparatus comprises a lever arm connected at one end thereof to said spindle and connected at its other end to a toe pedal means. An actuating rod is operatively connected to said toe pedal, and the rod is reciprocated to move said lever arm and thus said spindle by a solenoid which is actuated selectively by a pair of push button switches mounted on the handle bar of the motorcycle.

OBJECTIVE 1. To provide a novel and useful means for electrically shifting gears in a gear box having a ratchet type gear shifting means. 2. To provide a semiautomatic electrical gear shifting apparatus for gear boxes wherein the gear shifting lever may be moved in the same plane of movement of the driven member or actuating rod of the electrical drive means. 3. To provide a semiautomatic electrical gear shifting apparatus for use on motorcycles having ratchet type gear shifting means.

76

SUMMARY

The project relates to semi-automatic electric gear shifting apparatus for use in shifting gears in gear boxes of motorcycles and the like, wherein gears are shifted by rotating a spindle operably connected to a ratchet type gear shifting means, said spindle being rotated through a relatively small arc, the number of degrees of the arc being determined by the distance the ratchet means is required to move in effecting a change in the gears in the gear box. The spindle is thereafter returned to an original neutral position, said ratchet means being disengaged from the gear changing means during said return of said spindle to said original neutral position. In accordance with the present invention, the gear shifting apparatus comprises, in combination, a shifting lever arm operably connected at one end thereof to the spindle and connected at its opposite end to a cylindrical toe pedal means parallel to said lever arm. An electric drive means is provided for moving the lever arm and spindle and includes a connecting rod connected to said toe pedal means, switching means mounted on the handle bar of the motorcycle, and a solenoid electrically connected to a power source through said switches. The electric gear shifting apparatus when energized selectively through said switches imparts a rotational force to the spindle and thereby operates the ratchet gear shifting means in the gear box. Each time the apparatus is energized, one gear shifting cycle is completed and upon this apparatus being de-energized the lever arm is returned to the neutral position, being ready for the next shifting cycle. The manual operation of the gear shift lever arm of a motorcycle by providing a precise movement of the lever arm in a predetermined manner and through a precise arc, thus providing a more uniform and reliable means of shifting gears. Furthermore, the mere selective pressing of the electrical switching means on the handle bar is all that is required to effect the gear change, without the use of the gear disengaging clutch because the movement of the gear shifting arm is sufficiently rapid so as to not damage the gears while effecting the gear shift. The use of this equipment makes possible the adaptation of motors of this type, namely ratchet type gear shifting means gear boxes to a variety of uses not heretofore possible wherein manual operation of the shifting mechanism is not possible or is prohibitively complicated in that all that is required is a source of electrical power carried by flexible wires from the switching means to the electrical drive means. DETAILED DESCRIPTION A preferred embodiment of the semi-automatic electric gear shifting apparatus for motor cycles is shown in FIGS. 1-8, wherein an electric drive means 10, shown in FIGS. 2, 3, and 4, comprises a double acting electric solenoid. The mechanical details of said preferred embodiment are illustrated in FIGS. 1 through 7, and the electrical schematic circuit is shown in FIG. 8. The embodiment herein comprises in combination an electrical switching means generally indicated at 11 electrically operably connected to an electrical power source 12. The double acting electrical solenoid 10 is mounted on the motorcycle engine by means of a mounting bracket 13 shown in FIG. 6, said solenoid being operable by the switching means 11. A solenoid connecting rod 14 is operably connected to a solenoid core 15 of said solenoid, said rod being operably connected at its opposite end to the toe pedal 16 of a motorcycle shifting lever arm 17.

77

78

The switching means is generally indicated at 20 and comprises an upper momentary contact push-button switch 18 and a lower momentary push-button switch 19 of the type wherein an electrical circuit is closed when the push-buttons 18 or 19 are depressed and opened when the push-buttons are not depressed. A switch mounting bracket 21 is mounted on a motorcycle handle bar 22 adjacent ot an inward terminating portion 23 of the bar which is generally indicated at 24. Each of the switches 18 and 19 has a power source lead wire 25 electrically attached thereto and connected to the power source 12, and each of the switches has a solenoid connecting lead wire 26. The double acting electrical solenoid 10 is shown in detail in the cross-sectional view of FIG. 4 and comprises a cylindrical casing 27, an upper end piece 28 and a lower end piece 29 having a rod opening 30 there through and centrally located therein. The end pieces enclose and partially define a cylindrical casing, within which is mounted a cylindrical solenoid core guide 31 substantially smaller in diameter than said casing and having wound thereon an upper solenoid winding 32 and a lower solenoid winding 33, which windings are insulated from the casing and core guide, the core guide including a spacer 34 between the windings. The windings each have a ground lead wire 35 connected in common with each other and having a single lead wire 36 exiting through a wire exit port 37 located at about the mid-point of the casing. The upper winding has an upper switch connecting lead wire 38 and the lower winding has a lower switch connecting lead wire 39, both of which are insulated from each other and exit through said wire exit port. The solenoid core guide has a solenoid core 15 there within which is movable within the core guide along the direction of the major axis thereof, said core being normally located adjacent the spacer 34 and being of such di nension as to provide the desire travel when a winding is energized. The core 15 has an upper end 40 and lower end 41, both being conical in shape and of such dimension as to fit into cone shaped sockets 42 in the end pieces. The core is formed with a central opening 43 in which is inserted a solenoid connecting rod 14, said rod being affixed to said core by means of a pin 44 inserted into the core through hole 45. The pin 44 extends through an opening 46 in the rod 14 in alignment with said hole 45. The solenoid connecting rod exits through the rod opening 30 in the lower end piece 29. The rod has a core end 47, a lower rod end 48, and a shank portion 49 there between. The lower rod end has attached thereto a toe pedal bracket 50, said bracket being operably connected to a toe pedal 16 of a gear shifting lever arm 17, said lever arm being operably connected to a gear shifting spindle 51. The electrical connections are made by connecting the upper switch solenoid connecting lead wire to the upper winding upper switch connecting lead wire, connecting the lower switch solenoid connecting lead wire to the lower winding lower switch connecting lead wire, connecting the solenoid winding ground lead to the power source ground lead 52, and connecting the switch power source lead wire to the power source "hot" terminal 53. Depressing the upper push-button 18 will then impart a clockwise rotation to the gear shifting spindle, the length of arc being determined by the length of the travel of the core within the solenoid. Depressing the lower push-button 19 will impart a counter clockwise rotation to the gear shifting spindle, the length of arc determined as aforesaid. Releasing either push-button causes the spindle to return to its neutral position. The appropriate push-button is operated alternately until the desired gear ratio is achieved on the motorcycle. Other embodiments of the electrical drive means are shown in FIGS. 9-10, and FIG. 11. In FIG. 9, the electrical drive means comprises a double acting relay type solenoid shown schematically at 54 wherein a gear shifting lever arm 55 is so constructed that it is directly
79

acted upon by the energized solenoid coil. The lever arm 55 has a forward end 56 being located in a neutral position 57 intermediate between a lower solenoid pole piece 58 and an upper solenoid pole piece 59. The forward end of the arm has secured thereto a highly magnetically permeable metal means 60 shaped to match the said pole pieces as to dimensions of mating surfaces 61 thereof. The arm 55 has a rearward end spindle clamping means 62 thereon clamped to a gear shifting spindle 63. Opposing spring means 65 engage opposite sides of shank portion 64 of the lever arm 55 approximately mid-point thereon, said spring means providing the force to maintain the arm 55 in a neutral position mid-way between said pole pieces when the solenoid coils are not energized. FIG. 10 shows the schematic circuit and a diagram of the F^TG. 9 embodiment. As can be observed, when one of the respective pole piece windings is energized, the magnetically permeable metal plate means 60 on the lever arm is drawn there toward thereby imparting a rotational motion to the gear shifting spindle. Upon de-energizing the solenoid coil, the spring means causes the lever arm to return to its neutral position. Each time the coil is energized, the shift in gear ratio is accomplished within the design parameters of the gear mechanism of the motorcycle. A third embodiment is shown in FIG. 11 wherein a reversible motor means 66 has operably connected thereto a rotatable eccentric wheel gear 67 positioned in a channel member 68. The latter is operably connected to a connecting rod 69 operably connected to a gear shifting lever arm 70 which in turn is operably connected to the gear shifting spindle 71. Energizing the motor to operate in a clockwise direction causes the peak 72 of the eccentric wheel gear to rotate in the channel 68 resulting in upward movement of the channel and rod 69 connected thereto, thereby causing the spindle to rotate in a clockwise direction. Reversing the motor causes the spindle to rotate in a counter clockwise direction as a result of the peak 72 of the eccentric gear engaging the lower surface 73 of said channel, thereby effecting rotation of the spindle in a counter clockwise direction. CONCLUSION 1. A semi-automatic electrical gear shifting apparatus for a motorcycle for shifting gears of a ratchet type gear shifting means comprising in combination: a. an electrical switching means comprising a pair of switches mounted on the handle bar of the motorcycle, said switching means being electrically operably connected to b. an electrical power source, c. electrical drive means electrically connected to said power source through said switches, said electrical drive means including a solenoid, an actuating rod operatively connected to said solenoid, said actuating rod in turn being connected to a gear shifting lever arm through a toe pedal of the motorcycle, said lever arm being connected to a gear shifting spindle of the motorcycle gear mechanism, the connection between said lever arm and said spindle being such that when one of said switches is actuated said lever arm is moved by said solenoid to rotate said spindle in a first direction to change gears and when the other of said switches is activated said lever arm is moved by said solenoid to rotate said spindle in a second direction to change gears.
80

2. A semi-automatic electrical gear shifting apparatus as set forth in claim 1 wherein said switching means is mounted on a clamp mounted near an inward terminating end of the handle bar handle, said drive means comprising a double ended electrical solenoid, said solenoid having an upper winding electrically operably connected to one of said switches, and a lower winding electrically operably connected to the other of said switches, the electrical operation of said windings being independent of each other, said solenoid being mounted on a bracket mounted on the motorcycle engine above said toe pedal, said solenoid including a core movably located within said solenoid and operably connected to said actuating rod, said actuating rod having a toe pedal clamp means connected thereto at its lower end, with said toe pedal clamp means in turn being secured to said toe pedal. 3. A semi-automatic electrical gear shifting apparatus for a motorcycle for shifting gears of a ratchet type gear shifting means comprising in combination: a. an electrical switching means comprising a pair of switches mounted on the handlebar of the motorcycle, said switching means being electrically operably connected to b. an electrical power source, c. electrical drive means electrically connected to said power source through said switches, said electrical drive means comprising a double-acting relay type solenoid having an upper pole piece and a lower pole piece, a gear shifting lever arm positioned between said pole pieces, said lever arm having mounted at its forward end a magnetically permeable metal plate means, said plate means having upper and lower surfaces shaped to mate with said upper and lower pole pieces, the rearward end of said lever arm being clamped to a gear shifting spindle, spring means engaging both sides of said lever arm intermediate the ends thereof, said spring means providing a force to maintain said lever arm in a neutral position located intermediate between said solenoid pole pieces, said switches when alternately actuated moving said lever arm toward one or the other of said pole pieces thereby rotating said spindle in the corresponding direction. 4. A semi-automatic electrical gear shifting apparatus for a motorcycle for shifting gears of a ratchet type gear shifting means comprising in combination: a. an electrical switching means comprising a pair of switches mounted on the handle bar of the motorcycle, said switching means being electrically operably connected to, b. an electrical power source,

81

c. electrical drive means electrically connected to said power source through said switches, said electrical drive means comprising a reversible electric motor, a rotatable eccentric wheel gear driven by said motor, a channel member within which said wheel gear is mounted, said channel member being rigidly connected to a shifting lever arm through a connecting rod, said lever arm in turn being connected to a gear shifting spindle, whereby actuation of one of said switches results in rotation of said eccentric wheel gear in one direction to correspondingly rotate said spindle, and actuation of the other of said switches rotates said eccentric wheel gear in the opposite direction for corresponding reverse rotation of said spindle.

**************

82

ELECTROMAGNETIC SHOCK ABSORBER

ABSTRACT An electromagnetic shock absorber for dampening the vertical physical movement transferred from the wheel assembly of a vehicle to the frame assembly of the vehicle. The electromagnetic shock absorber includes a housing with a perimeter wall extending between a first end portion and a second end portion, a first electromagnetic assembly positioned within the housing and coupled to the first end portion of the housing, a second electromagnetic assembly positioned within the housing and coupled to the second end portion of the housing, a rod assembly with a first portion being slideably positionable in the housing, and a moving electromagnetic assembly coupled to a first end of the first portion and positioned between the first electromagnetic assembly and the second electromagnetic assembly within the housing.

SUMMARY This project relates to shock absorbers and more particularly pertains to a new electromagnetic shock absorber for dampening the vertical physical movement transferred from the wheel assembly of a vehicle to the frame assembly of the vehicle. The use of shock absorbers is known in the prior art. More specifically, shock absorbers heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements. The electromagnetic shock-absorber includes a housing with a perimeter wall extending between a first end portion and a second end portion, a first electromagnetic assembly positioned within the housing and coupled to the first end portion of the housing, a second electromagnetic assembly positioned within the housing and coupled to the second end portion of the housing, a rod assembly with a first portion being slideably positionable in the housing, and a moving electromagnetic assembly coupled to a first end of the first portion and positioned between the first electromagnetic assembly and the second electromagnetic assembly within the housing. In these respects, the electromagnetic shock absorber according to the present invention substantially departs from the conventional concepts and designs of
83

the prior art, and in so doing provides an apparatus primarily developed for the purpose of dampening the vertical physical movement transferred from the wheel assembly of a vehicle to the frame assembly of the vehicle. OBJECTIVE 1. To provide a new electromagnetic shock absorber apparatus and method which has many of the advantages of the shock absorbers mentioned heretofore and many novel features that result in a new electromagnetic shock absorber which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art shock absorbers, either alone or in any combination thereof. 2. To provide a new electromagnetic shock absorber which may be easily and efficiently manufactured and marketed. 3. To provide a new electromagnetic shock absorber which is of a durable and reliable construction. 4. To provide a new electromagnetic shock absorber which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such electromagnetic shock absorber economically available to the buying public. 5. To provide a new electromagnetic shock absorber which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith. 6. To provide a new electromagnetic shock absorber for dampening the vertical physical movement transferred from the wheel assembly of a vehicle to the frame assembly of the vehicle. 7. To provide a new electromagnetic shock absorber which includes a housing with a perimeter wall extending between a first end portion and a second end portion, a first electromagnetic assembly positioned within the housing and coupled to the first end portion of the housing, a second electromagnetic assembly positioned within the housing and coupled to the second end portion of the housing, a rod assembly with a first portion being slideably positionable in the housing, and a moving electromagnetic assembly coupled to a first end of the first portion and positioned between the first electromagnetic assembly and the second electromagnetic assembly within the housing. 8. To provide a new electromagnetic shock absorber that can be retrofitted to existing vehicles. 9. To provide a new electromagnetic shock absorber that provides enhanced performance over conventional shock absorbers.

84

DETAILED DESCRIPTION

85

With reference now to the drawings, and in particular to FIG. 1 through 4 thereof, a new electromagnetic shock absorber embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described. As best illustrated in FIGS. 1 through 4, the electromagnetic shock absorber 10 generally comprises an housing 20, a first electromagnet assembly 30, a second electromagnet assembly 40, a moving electromagnet assembly 50, and a rod assembly 60. The housing 20 includes a first end portion 21 and a second end portion 23. The housing 20 includes a perimeter wall 27, which extends from the first end portion 21 to the second end portion 23. The second end portion 23 includes a rod aperture 24, which extends through the second end portion 23.The first electromagnet assembly 30 is positioned within an interior of the housing 20 defined by the first 21 and second end portions 23 and the perimeter wall 27 of the housing 20. The first electromagnet assembly 30 is positioned adjacent the first end portion 21 of the housing 20. The second electromagnet assembly 40 is positioned within an interior of the housing 20 defined by the first 21 and second end portions 23 and the perimeter wall 27 of the housing 20. The second electromagnet assembly 40 is positioned adjacent the second end portion 23 of the housing 20. The rod assembly 60 includes a rod member with a rod member first portion 62 and a rod member second portion 64. The rod member first portion 62 extends into the housing 20 through the rod aperture 24. The moving electromagnet assembly 50 is coupled to the rod member first portion 62. The moving electromagnet assembly 50 is positioned within the housing 20. The first electromagnet assembly 30 comprises an upper plate member 31, a lower plate member 33, a shaft portion 35, a conductive member 36, and a pair of conductive terminals 38. The upper plate 31 is coupled to the first end portion 21 of the housing 20. The upper plate 31 and the lower plate 33 are in a substantially parallel spaced relationship. The shaft portion 35 extends between the upper plate 31 and the lower plate 33. The shaft portion 35 includes an upper end and a lower end. The upper end is coupled to a medial portion of the upper plate member 31. The lower end is coupled to a medial portion of the lower plate member 33 such that the first electromagnet assembly 30 is fixedly positioned adjacent to the first end portion 21 of the housing 20. The first end portion 21 of the housing 20 includes a pair of connecting apertures. The connecting apertures extend through the perimeter wall 27. Each of the pair of conductive terminals 38 extends through an associated one of the pair of connecting apertures such that a first end of each of the pair of conductive terminals 38 is positioned within the interior of the housing 20, and a second end of each one of the pair of conductive terminals is positioned without the housing 20. The conductive member 36 includes a conductive member first end and a conductive member second end. The conductive member first end is coupled with an associated first end of a first one of the pair of conductive terminals 38. The conductive member second end is coupled with an associated first end of a second one of the pair of conductive terminals 38 such that the first one of the pair of conductive terminals 38 is in electrical communication with the second one of the pair of conductive terminals 38. The second electromagnet assembly 40 comprising an upper plate member 41, a lower plate member 43, a shaft portion 45, a conductive member 46, and a pair of conductive terminals 48. The lower plate 43 is coupled to the second end portion 23 of the housing 20. The upper
86

plate 41 and the lower plate 43 are in a substantially parallel spaced relationship. The shaft portion 45 extends between the upper plate 41 and the lower plate 43. The shaft portion 45 includes an upper end and a lower end. The upper end is coupled to a, medial portion of the upper plate member 41. The lower end is coupled to a medial portion of the lower plate member 43 such that the second electromagnet assembly 40 is fixedly positioned adjacent to the second end portion 23 of the housing 20. The second end portion 23 of the housing 20 includes a pair of connecting apertures. The connecting apertures extend through the perimeter wall 27. Each of the pair of conductive terminals 48 extends through an associated one of the pair of connecting apertures such that a first end of each of the pair of conductive terminals 48 is positioned within the interior of the housing 20, and a second end of each one of the pair of conductive terminals 48 is positioned without the housing 20.The conductive member 46 includes a conductive member first end and a conductive member second end. The conductive member first end is coupled with an associated first end of a first one of the pair of conductive terminals 48. The conductive member second end is coupled with an associated first end of a second one of the pair of conductive terminals 48 such that the first one of the pair of conductive terminals 48 is in electrical communication with the second one of the pair of conductive terminals 48. The lower plate member 43 of the second electromagnet assembly 40 includes a lower rod aperture 44. The upper plate member 41 of the second electromagnet assembly 40 includes an upper rod aperture 42. The shaft portion 45 of the second electromagnet assembly 40 includes a shaft aperture. The lower rod aperture 44, the upper rod aperture 42, and the shaft aperture each are aligned with the rod aperture 24 of the second end portion 23 of the housing 30 such that the rod member first portion 62 is slidably insertable into the interior of the housing 20. The conductive member 36 of the first electromagnet assembly 30 includes a length wrapped around, an outside surface of the shaft portion 35. The conductive member 36 is for conducting an electrical current. The length of the conductive member 36 is wrapped around the shaft portion 35 such that a magnet flux is generated by the electrical current passing through the conductive member 36. The conductive member 46 of the second electromagnet assembly 40 includes a length wrapped around an outside surface of the shaft portion 45. The conductive member 46 is for conducting an electrical current. The length of the conductive member 46 is wrapped around the shaft portion 45 such that a magnet flux is generated by the electrical current passing through the conductive member 46. The upper 31 and lower plates 33 of the first electromagnet assembly 30 comprise a substantially ferrous material such that the upper 31 and lower plates 33 conduct a magnetic flux. The upper 41 and lower plates 43 of the second electromagnet assembly 40 comprise a substantially ferrous material such that the upper 41 and lower plates 43 conduct a magnetic flux. The current is conducted through the conductive member 36 of the first electromagnet assembly 30 is biased such that the lower plate 33 is magnetically charged to a first polarity. The current is conducted through the conductive member 46 of the second electromagnet assembly 40 is biased such that the upper plate 41 is magnetically charged to a polarity opposite the first polarity of the lower plate 33 of the first electromagnet assembly 30.
87

In an embodiment the lower plate 33 of the first electromagnet assembly 30 is magnetically positively charged and the upper plate 41 of the second electromagnet assembly 40 is negatively charged. The moving electromagnet assembly 50 includes an upper plate 51, a lower plate 53, a shaft portion 55, a conductive member 56, and a pair of connecting leads 57. The upper plate 51 and the lower plate 53 are in a substantially parallel spaced relationship. The shaft portion 45 extends between the upper 51 and lower plates 53. The shaft portion 55 includes an interior cavity defined by a perimeter wall. The shaft member 55 includes a connecting lead aperture. Each of the upper 51 and lower plates 53 and the shaft portion 55 is coupled to the rod member first portion 62 such that sliding the rod member first portion 62 into and out of the interior of the housing 20 through the rod aperture 24 moves the moving electromagnet assembly 50 between the lower plate 33 of the first electromagnet assembly 30 and the upper plate 41 of the second electromagnet assembly 40. The conductive member 56 of the moving electromagnet assembly 50 includes a first end, a second end, and a length. The length of the conductive member 56 is wrapped around the shaft portion 55. The first and second ends of the conductive member 56 are positioned through the connecting lead aperture. The first end is coupled to a first one of the connecting leads 57. The second end is coupled to a second one of the connecting leads 57 such that the connecting leads 57 are in electrical communication through the conductive member 56. The conductive member 56 of the moving electromagnet assembly 50 includes a length wrapped around an outside surface of the shaft portion 55. The conductive member 56 is for conducting an electrical current. The length of the conductive member 56 is wrapped around the shaft portion 55 such that a magnet flux is generated by the electrical current passing through the conductive member 56. The upper 51 and lower plates 53 of the moving electromagnet assembly 50 comprise a substantially ferrous material such that the upper 51 and lower plates 53 conduct a magnetic flux. A housing connector flange 25 has an aperture 26. The housing connector flange 25 is substantially cylindrical. The housing 20 includes a protrusion 22 extending from a top surface of the housing 20. The housing connector flange 25 is coupled to the protrusion 22 such that a longitudinal axis of the housing connector flange 25 is substantially perpendicular with a longitudinal axis of the housing 20. The housing connector flange 25 is designed for coupling the housing 20 to a frame of a vehicle. The rod member second portion 64 is a rod flange. The rod flange 64 has an aperture 66. The rod flange 64 is substantially cylindrical. The rod flange 64 is coupled to the rod member first portion 62 such that a longitudinal axis of the rod flange 64 is substantially perpendicular with a longitudinal axis of the rod member first portion 62. The rod flange 64 is designed for coupling the rod assembly 60 to a control arm of a vehicle. The rod flange 64 includes a pair of conductive terminals 58. Each of the conductive terminals 58 is electrically coupled to an associated one of a pair of connecting lead 57. The rod member first portion 62 is substantially hollow. Each of the pair of connecting leads 57 is positioned in the rod member first portion 62. The conductive members 36,46,56 of
88

each of the first electromagnet assembly 30, second electromagnet assembly 40, and moving electromagnet assembly 50 are in electrical electromagnet assembly 30 is magnetically charged to a first polarity. The upper plate 51 of the moving electromagnetic assembly 50 is magnetically charged to the same first polarity. The upper plate 41 of the second electromagnetic assembly 40 is magnetically charged to a polarity opposed to the polarity of the lower plate 33 of the first electromagnet assembly 30. The lower plate 53 of the moving electromagnet assembly 50 is magnetically charged to the same polarity as the upper plate 41 of the second electromagnet 40. Thus the moving electromagnet assembly 50 is repelled by the lower plate 33 of the first electromagnet assembly 30 and the moving electromagnet assembly 50 is repelled by the upper plate 41 of the second electromagnet assembly 40 such that a sliding motion of the rod assembly 60 is damped by the magnetic flux of the electromagnet assemblies 30, 40, 50. As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. CONCLUSION 1. An electromagnetic shock absorber comprising: an housing, said housing having a first end portion and a second end portion, said housing having a perimeter wall extending from said first end portion to said second end portion, said second end portion having a rod aperture extending there through; a first electromagnet assembly, said first electromagnet assembly being positioned within an interior of said housing defined by said first and second end portions and said perimeter wall of said housing, said first electromagnet assembly being positioned adjacent said first end portion of said housing; a second electromagnet assembly, said second electromagnet assembly being positioned within an interior of said housing defined by said first and second end portions and said perimeter wall of said housing, said second electromagnet assembly being positioned adjacent said second end portion of said housing; a rod assembly, said rod assembly having a rod member including an rod member first portion and a rod member second portion, said rod member first portion extending into said housing through said rod aperture; a moving electromagnet assembly, said moving electromagnet assembly being coupled to said rod member first portion, said moving electromagnet assembly being positioned within said housing; said moving electromagnet assembly having an upper plate, a lower plate, a shaft portion, a conductive member, and a pair of connecting leads; said upper plate and said lower plate being in a fixed substantially parallel spaced relationship with respect to each other, said shaft portion extending between said upper and lower plates for holding said upper and lower plates in said fixed relationship; said shaft portion having an interior cavity defined by a perimeter wall, said shaft member having a connecting lead aperture; each of said upper and lower plates and said shaft portion being coupled to said rod member such that sliding said rod member into and out of said interior of said housing through said rod aperture moves said moving electromagnet assembly between a lower plate of said first electromagnet assembly and an upper plate of said second electromagnet assembly.
89

2. The electromagnetic shock absorber of claim 1, further Comprising: said first electromagnet assembly comprising an upper plate member, said lower plate member, a shaft portion, a conductive member, and a pair of conductive terminals; said upper plate being coupled to said first end portion of said housing, said upper plate and said lower plate being in a substantially parallel spaced relationship, said shaft portion extending between said upper plate and said lower plate; said shaft portion having an upper end and a lower end, said upper end being coupled to a medial portion of said upper plate member, said lower end being coupled to a medial portion of said lower plate member such that said first electromagnet assembly being fixedly positioned adjacent to said first end portion of said housing; said first end portion of said housing having a pair of connecting apertures, said connecting apertures extending through said perimeter wall; each of said pair of conductive terminals extending through an associated one of said pair of connecting apertures such that a first end of each of said pair of conductive terminals being positioned within said interior of said housing and a second end of each one of said pair of conductive terminals being positioned without said housing; said conductive member having a conductive member first end and a conductive member second end, said conductive member first end being coupled with an associated first end of a first one of said pair of conductive terminals, said conductive member second end being coupled with an associated first end of a second one of said pair of conductive terminals such that said first one of said pair of conductive terminals being in electrical communication with said second one of said pair of conductive terminals. 3. The electromagnetic shock absorber of claim 2, further comprising: said second electromagnet assembly comprising said upper plate member, a lower plate member, a shaft portion, a conductive member, and a pair of conductive terminals; said lower plate being coupled to said second end portion of said housing, said upper plate and said lower plate being in a substantially parallel spaced relationship, said shaft portion extending between said upper plate and said lower plate; said shaft portion having an upper end and a lower end, said upper end being coupled to a medial portion of said upper plate member, said lower end being coupled to a medial portion of said lower plate member such that said second electromagnet assembly being fixedly positioned adjacent to said second end portion of said housing; said second end portion of said housing having a pair of connecting apertures, said connecting apertures extending through said perimeter wall; each of said pair of conductive terminals extending through an associated one of said pair of connecting apertures such that a first end of each of said pair of conductive terminals being positioned within said interior of said housing and a second end of each one of said pair of conductive terminals being positioned without said housing; said conductive member having a conductive member first end and a conductive member second end, said conductive member first end being coupled with an associated first end of a first one of said pair of conductive terminals, said conductive member second end being coupled with an associated first end of a second one of said pair of conductive terminals such that said first one of said pair of conductive terminals being in electrical communication with said second one of said pair of conductive terminals. 4. The electromagnetic shock absorber of claim 3, further comprising: said lower plate member of said second electromagnet assembly having a lower rod aperture extending there through; said upper plate member of said second electromagnet assembly having an upper
90

rod aperture extending there through; said shaft portion of said second electromagnet assembly having a shaft aperture extending there through; said lower rod aperture, said upper rod aperture, and said shaft aperture each being aligned with said rod aperture of said second end portion of said housing such that said rod member is slidably insertable into said interior of said housing. 5. The electromagnetic shock absorber of claim 3, further comprising: said conductive member of said first electromagnet assembly having a length wrapped around an outside surface of said shaft portion, said conductive member being for conducting an electrical current, said length of said conductive member being wrapped around said shaft portion such that a magnet flux is generated by said the electrical current passing through said conductive member; said conductive member of said second electromagnet assembly having a length wrapped around an outside surface of said shaft portion, said conductive member being for conducting an electrical current, said length of said conductive member being wrapped around said shaft portion such that a magnet flux is generated by said the electrical current passing through said conductive member. 6. The electromagnetic shock absorber of claim 5, further comprising: said upper and lower plates of said first electromagnet assembly comprising substantially ferrous material such that said upper and lower plates conduct a magnetic flux; said upper and lower plates of said second electromagnet assembly comprising substantially ferrous material such that said upper and lower plates conduct a magnetic flux. 7. The electromagnetic shock absorber of claim 6, further comprising: the current being conducted through said conductive member of said first electromagnet assembly is biased such that said lower plate being magnetically charged to a first polarity; the current being conducted through said conductive member of said second electromagnet assembly is biased such that said upper plate being magnetically charged to a polarity opposite the first polarity of the lower plate of said first electromagnet assembly. 8. The electromagnetic shock absorber of claim 7, further comprising: wherein said lower plate of said first electromagnet assembly being magnetically positively charged and said upper plate of said second electromagnet assembly being negatively charged. 9. The electromagnetic shock absorber of claim 1, further comprising: said conductive member of said moving electromagnet assembly having a first end, a second end, and a length, said length of said conductive member being wrapped around said shaft portion; said first and second ends of said conductive member being positioned through said connecting lead aperture, said first end being coupled to a first one of said connecting leads, said second end being coupled to a second one of said connecting leads such that said connecting leads being in electrical communication through said conductive member. 10. The electromagnetic shock absorber of claim 9, further comprising: said conductive member of said moving electromagnet assembly having a length wrapped around an outside surface of said shaft portion, said conductive member being for conducting an electrical current, said length of said conductive member being wrapped around said shaft portion such that a magnet flux is generated by said the electrical current passing through said conductive member.

91

11. The electromagnetic shock absorber of claim 10, further comprising: said upper and lower plates of said moving electromagnet assembly comprising substantially ferrous material such that said upper and lower plates conduct a magnetic flux. 12. The electromagnetic shock absorber of claim 1, further comprising: a housing connector flange; said housing connector flange having an aperture extending therethrough, said housing connector flange being substantially cylindrical; said housing having a protrusion extending from a top surface of said housing, said housing connector flange being coupled to said protrusion such that a longitudinal axis of said housing connector flange being substantially perpendicular with a longitudinal axis of said housing; said housing connector flange being adapted for coupling said housing to a frame of a vehicle. 13. The electromagnetic shock absorber of claim 1, further comprising: said rod member second portion comprising a rod flange, said rod flange having an aperture extending there through, said rod flange being substantially cylindrical, said rod flange being coupled to said rod first member first portion such that a longitudinal axis of said rod flange being substantially perpendicular with a longitudinal axis of said rod member first portion; said rod flange being adapted for coupling said rod member to a control arm of a vehicle. 14. The electromagnetic shock absorber of claim 13, further comprising: said rod flange having a pair of conductive terminals, each of said conductive terminals being electrically coupled to an associated one of a pair of connecting lead; said rod member first portion being substantially hollow, each of said pair of connecting leads being positioned in said rod member first portion. 15. An electromagnetic shock absorber comprising: an housing, said housing having a first end portion and a second end portion, said housing having a perimeter wall extending from said first end portion to said second end portion, said second end portion having a rod aperture extending there through; first electromagnet assembly, said first electromagnet assembly being positioned within an interior of said housing defined by said first and second end portions and said perimeter wall of said housing, said first electromagnet assembly being positioned adjacent said first end portion of said housing; a second electromagnet assembly, said second electromagnet assembly being positioned within an interior of said housing defined by said first and second end portions and said perimeter wall of said housing, said second electromagnet assembly being positioned adjacent said second end portion of said housing; a rod assembly, said rod assembly having a rod member including an rod member first portion and a rod member second portion, said rod member extending into said housing through said rod aperture; a moving electromagnet assembly, said moving electromagnet assembly being coupled to said rod member first portion, said moving electromagnet assembly being positioned within said housing; said first electromagnet assembly comprising an upper plate member, a lower plate member, a shaft portion, a conductive member, and a pair of conductive terminals; said upper plate being coupled to said first end portion of said housing, said upper plate and said lower plate being in a substantially parallel spaced relationship, said shaft portion extending between said upper plate and said lower plate; said shaft portion having an upper end and a lower end, said upper end being coupled to a medial portion of said upper plate member, said lower end being coupled to a medial portion of said lower plate member such that said first electromagnet assembly being fixedly positioned adjacent to said first end portion of said housing; said first end portion of said housing having
92

a pair of connecting apertures, said connecting apertures extending through said perimeter wall; each of said pair of conductive terminals extending through an associated one of said pair of connecting apertures such that a first end of each of said pair of conductive terminals being positioned within said interior of said housing and a second end of each one of said pair of conductive terminals being positioned without said housing; said conductive member having a conductive member first end and a conductive member second end, said conductive member first end being coupled with an associated first end of a first one of said pair of conductive terminals, said conductive member second end being coupled with an associated first end of a second one of said pair of conductive terminals such that said first one of said pair of conductive terminals being in electrical communication with said second one of said pair of conductive terminals; said second electromagnet assembly comprising an upper plate member, a lower plate member, a shaft portion, a conductive member, and a pair of conductive terminals; said lower plate being coupled to said second end portion of said housing, said upper plate and said lower plate being in a substantially parallel spaced relationship, said shaft portion extending between said upper plate and said lower plate; said shaft portion having an upper end and a lower end, said upper end being coupled to a medial portion of said upper plate member, said lower end being coupled to a medial portion of said lower plate member such that said second electromagnet assembly being fixedly positioned adjacent to said second end portion of said housing; said second end portion of said housing having a pair of connecting apertures, said connecting apertures extending through said perimeter wall; each of said pair of conductive terminals extending through an associated one of said pair of connecting apertures such that a first end of each of said pair of conductive terminals being positioned within said interior of said housing and a second end of each one of said pair of conductive terminals being positioned without said housing; said conductive member having a conductive member first end and a conductive member second end, said conductive member first end being coupled with an associated first end of a first one of said pair of conductive terminals, said conductive member second end being coupled with an associated first end of a second one of said pair of conductive terminals such that said first one of said pair of conductive terminals being in electrical communication with said second one of said pair of conductive terminals; said lower plate member of said second electromagnet assembly having a lower rod aperture extending therethrough; said upper plate member of said second electromagnet assembly having an upper rod aperture extending there through; said shaft portion of said second electromagnet assembly having a shaft aperture extending there through; said lower rod aperture, said upper rod aperture, and said shaft aperture each being aligned with said rod aperture of said second end portion of said housing such that said rod member is slidably insertable into said interior of said housing; said conductive member of said first electromagnet assembly having a length wrapped around an outside surface of said shaft portion, said conductive member being for conducting an electrical current, said length of said conductive member being wrapped around said shaft portion such that a magnet flux is generated by said the electrical current passing through said conductive member; said conductive member of said second electromagnet assembly having a length wrapped around an outside surface of said shaft portion, said conductive member being for conducting an electrical current, said length of said conductive member being wrapped around said shaft portion such that a magnet flux is generated by said the electrical current passing through said conductive member; said upper and lower plates of said first electromagnet assembly comprising substantially ferrous material such that said upper and lower plates conduct a magnetic flux; said upper and lower plates of said second electromagnet assembly comprising substantially ferrous material such that said upper and lower plates conduct a magnetic flux; the current being conducted through said conductive member of said first electromagnet assembly is biased such that said lower plate being
93

magnetically charged to a first polarity; the current being conducted through said conductive member of said second electromagnet assembly is biased such that said upper plate being magnetically charged to a polarity opposite the first polarity of the lower plate of said first electromagnet assembly; wherein said lower plate of said first electromagnet assembly being magnetically positively charged and said upper plate of said second electromagnet assembly being negatively charged; said moving electromagnet assembly having an upper plate, a lower plate, a shaft portion, a conductive member, and a pair of connecting leads; said upper plate and said lower plate being in a fixed substantially parallel spaced relationship with respect to each other, said shaft portion extending between said upper and lower plates for holding said upper and lower plates in said fixed relationship; said shaft portion having an interior cavity defined by a perimeter wall, said shaft member having a connecting lead aperture; each of said upper and lower plates and said shaft portion being coupled to said rod member such that sliding said rod member into and out of said interior of said housing through said rod aperture moves said moving electromagnet assembly between said lower plate of said first electromagnet assembly and said upper plate of said second electromagnet assembly; said conductive member of said moving electromagnet assembly having a first end, a second end, and a length, said length of said conductive member being wrapped around said shaft portion; said first and second ends of said conductive member being positioned through said connecting lead aperture, said first end being coupled to a first one of said connecting leads, said second end being coupled to a second one of said connecting leads such that said connecting leads being in electrical communication through said conductive member; said conductive member of said moving electromagnet assembly having a length wrapped around an outside surface of said shaft portion, said conductive member being for conducting an electrical current, said length of said conductive member being wrapped around said shaft portion such that a magnet flux is generated by said the electrical current passing through said conductive member; said upper and lower plates of said moving electromagnet assembly comprising substantially ferrous material such that said upper and lower plates conduct a magnetic flux; a housing connector flange; said housing connector flange having an aperture extending there through, said housing connector flange being substantially cylindrical; said housing having a protrusion extending from a top surface of said housing, said housing connector flange being coupled to said protrusion such that a longitudinal axis of said housing connector flange being substantially perpendicular with a longitudinal axis of said housing; said housing connector flange being adapted for coupling said housing to a frame of a vehicle; said rod member second portion comprising a rod flange, said rod flange having an aperture extending there through, said rod flange being substantially cylindrical, said rod flange being coupled to said rod first member first portion such that a longitudinal axis of said rod flange being substantially perpendicular with a longitudinal axis of said rod member first portion; said rod flange being adapted for coupling said rod member to a control arm of a vehicle; said rod flange having a pair of conductive terminals, each of said conductive terminals being electrically coupled to an associated one of a pair of connecting lead; said rod member first portion being substantially hollow, each of said pair of connecting leads being positioned in said rod member first portion. 16. The electromagnetic shock absorber of claim 15 further comprising: said conductive members of each of said first electromagnet assembly, second electromagnet assembly, and moving electromagnet assembly being in electrical communication with a current source such that said lower plate of said first electromagnet assembly being magnetically charged to a first polarity, said upper plate of said moving electromagnetic assembly being magnetically charged to the same first polarity; said upper plate of said second electromagnetic assembly being magnetically charged to a polarity opposed to the polarity of said lower plate of said
94

first electromagnet assembly, said lower plate of said moving electromagnet assembly being magnetically charged to the same polarity as said upper plate of said second electromagnet, whereby said moving electromagnet being repelled by said lower plate of said first electromagnet assembly and said moving electromagnet being repelled by said upper plate of said second electromagnet assembly such that a sliding motion of said rod assembly being damped by the magnetic flux of said electromagnet assemblies.

**************

95

ELECTRICALLY POWERED STEERING MECHANISM

ABSTRACT An electrically powered drive mechanism for providing assistance to a vehicle steering mechanism. The drive mechanism includes a clutch responsive to drivingly isolate the motor from an output shaft coupling when torque in excess of a selected level is transmitted through a clutch SUMMARY

This project relates to an electrically powered drive mechanism for providing powered assistance to a vehicle steering mechanism. According to one aspect of the project, there is provided an electrically powered driven mechanism for providing powered assistance to a vehicle steering mechanism having a manually rotatable member for operating the steering mechanism, the drive mechanism including a torque sensor operable to sense torque being manually applied to the rotatable member, an electrically powered drive motor drivingly connected to the rotatable member and a controller which is arranged to control the speed and direction of rotation of the drive motor in response to signals received from the torque sensor, the torque sensor including a sensor shaft adapted for connection to the rotatable member to form an extension thereof so that torque is transmitted through said sensor shaft when the rotatable member is manually rotated and a strain gauge mounted on the sensor shaft for producing a signal indicative of the amount of torque being transmitted through said shaft. Preferably the sensor shaft is non-rotatably mounted at one axial end in a first coupling member and is non-rotatably mounted at its opposite axial end in a second coupling member, the first and second coupling members being inter-engaged to permit limited rotation there between so that torque under a predetermined limit is transmitted by the sensor shaft only and so that torque above said predetermined limit is transmitted through the first and second coupling members. The first and second coupling members are preferably arranged to act as a bridge for drivingly connecting first and second portions of the rotating member to one another. The sensor shaft is of generally rectangular cross-section throughout the majority of its length. The strain gauge includes one or more SAW resonators secured to the sensor shaft. The

96

motor is drivingly connected to the rotatable member via a clutch. The motor includes a gear box and is concentrically arranged relative to the rotatable member.
DETAILED DESCRIPTION

Referring initially to FIG. 1, there is shown a vehicle steering mechanism 10 drivingly connected to a pair of steerable road wheels 12. The steering mechanism 10 shown includes a rack and pinion assembly 14 connected to the road wheels 12 via joints 15. The pinion (not shown) of assembly 14 is rotatably driven by a manually rotatable member in the form of a steering column 18 which is manually rotated by a steering wheel 19. The steering column 18 includes an electric powered drive mechanism 30 which includes an electric drive motor (not shown in FIG. 1) for driving the pinion in response to torque loadings in the steering column 18 in order to provide power assistance for the operative when rotating the steering wheel 19.

97

As schematically illustrated in FIG. 2, the electric powered drive mechanism includes a torque sensor 20 which measures the torque applied by the steering column 18 when driving the pinion and supplies a signal to a controller 40. The controller 40 is connected to a drive motor 50 and controls the electric current supplied to the motor 50 to control the amount of torque generated by the motor 50 and the direction of its rotation. The motor 50 is drivingly connected to the steering column 18 preferably via a gear box 60, preferably an epicyclic gear box, and a clutch 70. The clutch 70 is preferably permanently engaged during normal operation and is operative under certain conditions to isolate drive from the motor 50 to enable the pinion to be driven manually through the drive mechanism 30. This is a safety feature to enable the mechanism to function in the event of the motor 50 attempting to drive the steering column too fast and/or in the wrong direction or in the case where the motor and/or gear box have seized. The torque sensor 20 is preferably an assembly including a short sensor shaft on which is mounted a strain gauge capable of accurately measuring strain in the sensor shaft brought about by the application of torque within a predetermined range. Preferably the predetermined range of torque which is measured is 0-10 Nm; more preferably is about 1-5 Nm. Preferably the range of measured torque corresponds to about 0-1000 microstrain and the construction of the sensor shaft is chosen such that a torque of 5 Nm will result in a twist of less than 2° in the shaft, more preferably less than 1°. Preferably the strain gauge is a SAW resonator, a suitable SAW resonator being described in W 0 91/13832. Preferably a configuration similar to that shown in FIG. 3 of WO91/ 13832 is utilised wherein two SAW resonators are arranged at 45° to the shaft axis and at 90° to one another. Preferably the resonators operate with a resonance frequency of between 200 400 MHz and are arranged to produce a signal to the controller 40 of 1 MHz+500 KHz depending upon the direction of rotation of the sensor shaft. Thus, when the sensor shaft is not being twisted due to the absence of torque, it produces a 1 MHz signal. When the sensor shaft is twisted in one direction it produces a signal between 1.0 to 1.5 MHz. When the sensor shaft is twisted in the opposite direction it produces a signal between 1.0 to 0.5 MHz. Thus the same sensor is able to produce a signal indicative of the degree of torque and also the direction of rotation of the sensor shaft.

98

Preferably the amount of torque generated by the motor in response to a measured torque of between 0-10 Nm is 0 40 Nm and for a measured torque of between 1-5 Nm is 0-25 Nm. Preferably a feed back circuit is provided whereby the electric current being used by the motor is measured and compared by the controller 40 to ensure that the motor is running in the correct direction and providing the desired amount of power assistance. Preferably the controller acts to reduce the measured torque to zero and so controls the motor to increase its torque output to reduce the measured torque.

A vehicle speed sensor (not shown) is preferably provided which sends a signal indicative of vehicle speed to the controller. The controller uses this signal to modify the degree of power assistance provided in response to the measured torque. Thus at low vehicle speeds maximum power assistance will be provided and a high vehicle speeds minimum power assistance will be provided. The controller is preferably a logic sequencer having a field programmable gate array for example a XC 4005 as supplied by Xilinx. Such a controller does not rely upon
99

software and so is able to function more reliably in a car vehicle environment. It is envisaged that a logic sequence not having a field programmable array may be used. A specific construction of an electric power drive mechanism 10 is illustrated in FIG. 3. The mechanism 11 includes a housing 21 of generally cylindrical form having an input shaft coupling 22 at one axial end and an output shaft coupling 23 at the opposite axial end. A shaft assembly 25 extends between the input and output shaft couplings 22, 23, respectively, to provide a direct mechanical drive connection there between so that rotation of coupling 22 causes coupling 23 to rotate in unison therewith. The shaft assembly 25 includes a main shaft 26 of round cross-section which is connected at one axial to the output coupling 23 and at its opposite axial end to a sensor shaft 36 of the torque sensor 20. As seen in FIGS. 3 and 4, the sensor shaft 36 is of generally rectangular cross-section having circular sections at each end and is in turn connected to the input coupling 22. The shaft 36 is preferably of rectangular section
as this enables shafts having the same resistance to twist to be accurately produced by mass production techniques. The shaft may be machined or cast.

The input coupling 22 is more clearly shown in FIG. 5. The coupling 22 includes a first coupling member 122 which is secured by bolts 121 to a second coupling member 123. The bolts 121 pass through elongated slots 125 in the first coupling member 122 so that the first and second members 122, 123 can rotate relative to one another over a limited arc. The amount of relative angular displacement between the coupling members 122, 123 is determined by stop blocks 126 mounted on dowels 127 which co-operate with a recess (not shown) formed in coupling member 122. The coupling member 122 has a recess 128 for receiving the upper end of the sensor shaft 36. The upper axial end of the sensor shaft has a flat 36a formed thereon and a wedge 129 is provided for positively locking the upper end of

100

the sensor shaft in recess 128 by passing through a bore 129a. A grub screw 129b is preferably provided for insertion in bore 129a to prevent axial withdrawal of the wedge. The lower axial end of the sensor shaft 36 is located within a recess 130 of the second coupling member 123 and is fixedly secured thereto by grub screws 131 passing through threaded bores 132 formed about the periphery of member 123. A bearing 135 is located between the coupling members 122, 123 to provide a rotary connection there between. The size and shape and material used to construct sensor shaft 36 is chosen to provide a predetermined small amount of twist in the shaft when transmitting the maximum desired torque required to be input manually. In a typical arrangement for transmitting up to 5 Nm torque, the shaft 36 is about 50 mm and the diameter of the circular end portions is about 16 mm and the cross-section dimensions of the rectangular section are about 16x5 mm. With such a shaft mode from KE805 steel the measured strain at 5 Nm torque is about 500 microstrain and the angle of twist is less than 0.3°. The coupling members 122, 123 are arranged to permit unimpeded twist in the sensor shaft when transmitting torques below the predetermined value (typically 5 Nm) but rotatably engage to transmit torques in excess of the predetermined value. According, the sensor shaft is isolated from transmitting more than the predetermined torque value and so cannot be over strained. The sensor shaft 36 has mounted thereon a strain gauge 37 which is arranged to determine the amount of strain in sensor shaft 36 which is caused when the input coupling 32 is rotated. The strain gauge 37 is electrically coupled to the controller 40 (not shown in FIG. 3) via a capacitative coupling 42 defined by a pair of printed circuit boards 43, 44. The upper board 43 is connected to the input coupling member 123 to be rotated therewith and the lower board 44 is secured to the housing 21. The lower printed circuit board 44 contains a circuit for converting the 200 400 MHz signals produced by the resonators to the desired 1 MHz signal for transmission to the controller. It will be appreciated that the gauge 37 may be coupled to the controller through alternative means of coupling, as for example an inductive coupling. The motor 50 is preferably a brushless DC motor which is preferably a low speed, high torque, low torque ripple motor. The motor 50 is preferably a concentric motor surrounding the main shaft 26 and has an outer staler 51 secured to the housing 21 and an inner rotor 52 which drives a sun gear 53 of an epicyclic gear box 60. The gear box 60 has a stationary outer ring gear 55 mounted on the housing 21 so that output drive from the gear box is via the planetary gear carrier 57.

101

The planetary gear carrier 57 has a series of pins 58 which transmit drive to the main shaft 26 via the clutch 70. The clutch 70 is shown in greater detail in FIG. 6. The clutch 70 includes a drive disc assembly 170 comprising a pair of discs 171, 172 and compression springs 174 mounted on compression bolts 175 which are screw threadedly attached to disc 172. The springs 174 enable discs 171, 172 to move apart axially. The discs 171, 172 are driven by pins 58 on the gear carrier 57. The clutch 70 further includes a driven disc 176 having a tubular extension 177. The driven disc 176 is located within a recess 180 formed in disc 171 and is held in axial compression against disc 172 by a shoulder 183. Located between discs 176 and 172 is a series of balls 185 housed in pockets 186. Whilst balls 185 remain in pockets 186 drive is transmitted from disc 172 to disc 176. If torque in excess of a predetermined amount is transmitted between discs 172, 176, the discs are caused to separate axially and so drive there between is lost. The tubular extension 177 has an internal bore 179 which receives a tubular extension 123a of coupling member 123. Tubular extensions 123a and 177 are secured to one another and main shaft 26. Accordingly rotary drive to the main shaft 26 is provided by coupling member 123 and/or clutch 70. In the event of motor failure, clutch 70 will operate on manual rotation of column 18 to isolate the motor and so permit rotary drive to shaft 26 via the coupling member 123 only. The above described mechanism 30 provides a compact unit including both torque sensor and motor combined into a single housing. Typically the housing 21 is about 130 mm diameter and about 210 mm long. It is envisaged that the torque sensor 20 comprising coupling 22 in combination with the sensor shaft 36 and gauge 37 may be used as a separate assembly for incorporation into any rotating member for measuring torque being transmitted thereby. Such a sensor 20 may be used to control a separate motor which may or may not be concentric with the rotating member.
102

CONCLUSION 1. An electrically powered drive mechanism for providing powered assistance to a vehicle steering mechanism having a manually rotatable member for operating the steering mechanism, the drive mechanism including a housing of generally cylindrical form having an impact shaft coupling at one axial end for driving connection with the rotatable member and an output shaft coupling at its opposite axial end for driving connection with the vehicle steering mechanism, a shaft assembly extending between the input and output shaft couplings to provide a direct mechanical drive connection therebetween so that torque is transmitted through the shaft assembly when the rotatable member is rotated, the drive mechanism including a torque sensor operable to sense torque being manually applied to the rotatable member, an electrically powered drive motor housed within said housing and being concentrically arranged relative to said shaft assembly and a controller which is arranged to control the speed and direction of rotation of the drive motor in response to signals received from the torque sensor, the torque sensor including a sensor shaft which forms part of said shaft assembly so that torque transmitted through the shaft assembly is transmitted through said sensor shaft and a strain gauge mounted on the sensor shaft for producing a signal indicative of the amount of torque being transmitted through said sensor shaft, the motor being drivingly connected to an epicyclic gear assembly housed within said housing, the epicyclic gear assembly being drivingly connected to the output shaft coupling via a normally permanently engaged clutch, the clutch being responsive to drivingly isolate the motor from the output shaft coupling when torque in excess of a predetermined value is transmitted in one of two directions through the clutch. 2. A mechanism according to claim 1 wherein the sensor shaft is non-rotatably mounted at one axial end in a first coupling member and is non-rotatably mounted at its opposite axial end in a second coupling member, the first and second coupling members being interengaged to permit limited rotation therebetween so that torque under a predetermined limit is transmitted by the sensor shaft only and so that torque above said predetermined limit is transmitted through the first and second coupling members. 3. A mechanism according to claim 2 wherein the first and second coupling members are arranged to act as a bridge for drivingly connecting first and second portions of the rotating member to one another. 4. A mechanism according to any preceding claim wherein the sensor shaft is of generally rectangular crosssection throughout the majority of its length. 5. A mechanism according to claim 1, wherein the sensor shaft is constructed such that a torque of 5 N^m results in a twist of less than 2° about the axis of the shaft. 6. A mechanism according to claim 1, wherein the strain gauge includes one or more SAW resonators secured to the sensor shaft. 7. A mechanism according to claim 6 wherein the one or more resonators operate with a resonance frequency of between 200~00 MHz and are arranged to produce a signal to the controller of between 1.0 to 1.5 MHz when the sensor shaft is twisted in one direction and between 1.0 to 0.5 MHz when the sensor shaft is twisted in an opposite direction. **************
103

AUTOMATIC WINDOW WIPER CONTROL

ABSTRACT The project is directed to an automatic wiper control circuit for operating window wipers automatically when moisture is sensed. The control circuit additionally provides for increasing the
speed of a dual speed wiper motor when a high level of moisture is detected. The system comprises a moisture sensor which senses moisture thereon. A circuit associated with the moisture sensor converts the moisture level to DC voltage. At a preselected level of this DC voltage the wiper motor operates in one of its two different speeds. A lack of a predetermined amount of moisture terminates the wiper motor operation. If the control circuit terminates the wiper motor action during wiper sweep, the normal homing circuit of the wiper motor continues to operate the motor until the wiper blade or blades reach the wiper blade home position. Sequential illumination of a plurality of light emitting diodes (LEDS) occur during a wiping cycle when the circuit is operating normally. A switch is provided to remove the automatic wiper control circuit from the conventional automotive wiper motor circuit. A separate LED provides a visual indication of automatic wiper control circuit disconnection from the conventional automotive wiper motor circuit.

OBJECTIVE 1. To provide an automatic control for a windshield wiper motor which is responsive to moisture or rain deposited on the exterior surface of the windshield. 2. To provide a sensor comprised of a plurality of side-by-side conduction strips, pairs of which are multiplexed for sequential moisture sensing thereacross. 3. To provide means for automatically changing the speed of the wiper motor with changing moisture conditions. 4. To provide a wiper blade position sensor for sensing moisture conditions on the moisture sensor during the wiper blade sweep across the wiper blade position sensor. 5. To utilize the home-park switch of the wiper motor to return the wiper blade or blades to the home or stowed position after wiper motor termination by the automatic wiper motor control. 6. To provide LEDS for visually monitoring the operating sequence of the multiplexer circuits.

104

SUMMARY

The present invention relates generally to a wiper motor control system for clearing windows including, but not limited to, an automotive windshield or rear window wiper blade or blades, which automatically operates and controls the operating speed of a wiper blade or blades according to rain or moisture conditions. More particularly, the invention relates to a wiper motor control system having an exterior sensor which continually monitors moisture conditions on the windshield or rear window and is influenced thereby to remain inoperative or to operate the wiper motor in one of two speeds according to this influence. The sensor is positioned within an area swept by the wiper blades. This project is directed to the automatic control of window wiper motor including the windshield wiper motor of an automotive vehicle and a control which operates under all moisture or rain conditions to keep the window clear of moisture or rain. An automatic windshield wiper motor control of this nature allows the operator of an automotive vehicle to concentrate on driving when under adverse weather conditions and not break concentration directed to the automotive operation by continually adjusting the speed or operation of the windshield wiper blade or blades or adjusting existing time delay circuitry. Applicants provide an automotive windshield or rear window wiper motor control system which includes a novel sensor means comprised of a plurality of side-by side exposed conductive strips positioned on the external surface of the windshield or rear window in the path of a wiper blade sweep. A multiplexer circuit continues to select adjacent pairs of the conductive strips and connects a DC voltage to one end of one of a selected strip and connects one end of the other selected strip to the control circuit input. When moisture or water is present between adjacent strips simultaneously connected by the multiplexer circuit, the DC voltage conducts between the normally open circuit selected strips to the control circuit. The DC voltage level present at the control circuit input will depend on the amount of moisture or rain between the strips and the conductivity of that moisture or rain. When a selected level of DC voltage is present at the input of the control circuit the wiper motor will become operative. A slight amount of moisture or rain present, above a minimum preselected level, will operate the wiper motor at a first slow speed and an amount of moisture or rain exceeding a range for the selected level for low speed wiper motor operation will cause the wiper motor to operate at a second or faster speed when the motor is equipped for a multispeed operation. Additional circuits could be added to accomodate additional available wiper motor speeds greater than two. Most modern automotive vehicles are factory equipped with a standard two speed wiper motor and the explanation herein is directed to such a motor, but the invention should not be considered limited to two speed motors or to the application to automatic windshields or rear windows as the invention can be employed for use with single or multi-speed wiper motors which are used on any type of window, windshield and the like. The motor control circuit of the invention includes a wiper blade position sensor which when influenced by wiper blade passing there across initiates the control circuit to determine whether or not the wiper motor will be operated for an additional wiper blade sweep. The wiper blade position sensor terminates wiper motor operation in the absence of moisture or a level of moisture below a pre-set level on adjacent strips of the sensor. The wiper motor park switch present in modern conventional wiper motors continues to operate the wiper motor after the wiper blade position sensor has instructed the circuit of the invention to terminate
105

wiper motor operation until the wiper blade(s) have reached their home or normally stowed position(s). The sequencing of the multiplexer is monitored by light emitting diodes (LEDS) of the same or mixed different colors. The operation of these LEDS provide a pleasant "light show" as well as monitoring system operation and therefore are positioned within the view of the automobile operator and passengers. The presence of the LEDS illumination and failure of wiper action would indicate that the blade is frozen to the window or otherwise prevented from movement. A local control switch convenient to the operator allows the switching of the automatic wiper motor control system in or out of the normal wiper motor circuit, as selected by the operator. An LED associated with the local control switch illuminates when the automatic wiper motor system of the invention has been disconnected. DETAILED DISCRIPTION

Referring now to FIG. 1, there is shown a block diagram of the automatic wiper motor control system 10 of the present invention. The system comprises a sensor 12, a scanning circuit 14, an oscillator 16, a scan select circuit 18, a wiper blade position sensor 20, a filter 22, a high speed comparator 24^7 a control logic circuit 26, an adjustable reference voltage 28, a low/high speed wiper motor speed select circuit 30, and a wiper motor energize circuit 32. These circuits which are hereinafter described in greater detail are electrially interconnected as shown by the various connecting lines therebetween. The arrow heads on the interconnecting lines denote direction of signal or current flow there between.

106

Referring now also to FIG. 2 which shows, in partial cutaway, the forward portion of an automobile 34 incorporating the present invention. The automobile 34 typically includes a hood 36, top 38, dash 40, windshield 42, wiper motor 44, wiper motor to wipe blade linkage 46 and a pair of wiper blades 48. Shown centrally located on windshield 42 is the system moisture sensor 12. The moisture sensor is electrically connected to circuit components (hereinafter discussed in detail) contained within housing portions 15A and 15B which in turn are interconnected to the wiper blade position sensor 20. Wiper motor 44 is connected to 15A. Portion 15A of the housing portion is positioned out of view of the automobile operator generally under the hood 36 while portion 15B is mounted on the dash 40, for example, in view of the automobile operator. The wiper motor 44 is interconnected to the wiper blades 48, through conventionally known linkage 46 and therefore, no detailed explanation of the linkage is included herein.

107

Referring now specifically to FIGS. 3 and 4, a schematic diagram of the inter-connections of the various elements of an automobile wiper motor control system 10 is shown in FIG. 3 and a typical printed circuit type sensor 12 is shown in FIG. 4. The moisture sensor 12 is comprised of a plurality of side-by-side positioned exposed conductive elements 50. The spacing of these elements can be varied according the the moisture anticipated, or the amount of impurities within the expected moisture. The elements 50 have a width for example of from 1.0 to 100 mils. Typically the elements will be from 15 to 62 mils in width and spaced from 15 to 62 mils apart. The width of the conductive elements and their spacing is not critical and can be varied and still be utilized successfully to practice this invention. The elements 50 are generally partially disposed within an insulation
108

medium such as flexible plastic and the like. Typically flat strap harness material well known by the electronic art is satisfactory. The sensor 12 is adhered to the outer surface of the windshield with the exposed conductive elements 50 being positioned for encountering a wiper blade 48 during its normal to-and-fro sweep. Although, it is anticipated that only one wiper blade of a two wiper blade conventional automobile windshield wiping system will encounter the sensor 12 in its pass, both wipers' blades could encounter the sensor 12 in their sweep path without altering the operation of the automatic wiper motor control system of this invention. Each element 50 of the sensor 12, nine shown for the purpose of explanation, more or less could be employed, is connected to a separate output of a multiplexer 52. A second multiplexer 54 is connected to each elements 50 in the same manner as multiplexer 52. The multiplexers 52 and 54 are interconnected according to the manufacturers specifications so that one of the adjacent pairs of elements 50 are connected through a 100K ohm resistor 51 to a positive DC voltage source 56 to multiplexer 52 and the other one of the adjacent pair is connected to the output of multiplexer 54. It should be understood that the adjacent elements in a normal dry condition appear as an open circuit between the two multiplexers, preventing voltage from source 56 from being present on the output of the multiplexer 54. The amount of moisture on adjacent elements 50 and the amount of impurities in that moisture present determine the level of voltage present at the output of the multiplexer 54 for any given moisture condition. As the moisture accumulates on the sensor, each pair of adjacent elements 50 in turn provide a voltage level at the output of the multiplexer 54. This voltage level is stored in a capacitor 57 of 10 micro farads. This stored voltage in capacitor 57 is continually bleed to ground through a resistor 58 of 470K ohms. The theory is that when sufficient moisture accumulates on the sensor 12 between wiper blade sweeps, the capacitor will be sufficiently charged to overcome the bleed off through the resistor 58 and provide a voltage level at the inverting input of a voltage comparator 60. The voltage comparator 60 has its non-inverting input connected to the DC voltage source 56 through a 22K ohm resistor 62, a 3.3K resistor 63, and a 100K ohm potentiometer 64 to ground. The potentiometer 64 adjusts the desired level of DC voltage at the non-inverting positive input of the voltage comparator 60 in comparison to the DC voltage at the inverting input. The operation of the system sensitivity control will be hereinafter explained. A second voltage comparator 66 which also has its inverting input connected to the output of the multiplexer 54 and its non-inverting positive input connected to the common connection between resistors 62 and 63. The output of the voltage comparator 60 is connected to the DC voltage source 56 through a resistor 68 of 100K ohms as is comparator 66 through a resistor 70 of 100K ohms. Oscillator 16 comprises a pair of buffer inverters 72, a resistor 74 of 10K ohms, a resistor 76 of 27K ohms, and a capacitor 78 of 0.22 micro farads. The oscillator output is connected to clock terminal A of one portion of a dual up counter 80. The three outputs of this portion of the dual up-down counter 80 are connected to the sequence control of the multiplexers 52 and 54. The reset terminal of this portion of the dual up-down counter 80 is connected to ground potential. The enable of the second or other portion of the dual up counter 80 is connected to the DC voltage source 56. The clock terminal B of the up counter 80 is connected to a fourth
109

output terminal of the first section of the dual up counter which also provides a clock input to a flip-flop circuit 82. The output of the voltage comparator 60 is also connected to a terminal of an And gate 84 and an And gate 82 and the other inputs to the last mentioned And gates are provided from the DC voltage source 56 and the output of the wiper blade position sensor 20. The wiper blade position sensor output is also connected to the DC voltage source through a resistor 88 of 10 Kohms. Outputs from the other half of the up counter 80 are each connected to one input of four inverters 90-96. The outputs of each of these inverters are connected to the cathodes of light emitting diodes (LEDS) 98-104 respectively through associated resistors 106-112 of 680 ohms. The anodes of the LEDs are connected to the DC voltage source 56. The reset terminal of the flip-flop circuit 82 is connected to one end of a resistor 114 of 470K ohms and to one side of a capacitor 116 of I micro farad. The other end of resistor 114 is connected to ground and the opposite side of capacitor 116 is connected to the DC voltage source 56. The inverted output of the flip-flop circuit 82 is connected to the reset terminal of one of the counter sections of the dual up counter. The non-inverted output of the flip-flop circuit 82 is connected to the base of a transistor 118 through a resistor 120 of 1.8K ohms. The set terminal of the flip-flop circuit 82 is connected to ground. The output of the And gate 84 is connected to the "J" input and the output of the And gate 86 is connected to the "K" input of the flip-flop circuit 82. The output of the voltage comparator 66 is also connected to the base of transistor 122 through resistor 124 of 2.2K ohms. The emitter of transistor 122 is connected to the DC voltage source 56 and the collector is connected through the wiper motor speed relay coil 126 to ground. A diode 128 is connected across the coil 126. The relay coil operates to close a normally open relay switch 130 when the transistor 122 conducts. The relay switch 130 provides voltage to the high speed winding of the dual speed wiper motor 44. Dual speed wiper motors of this type are commonly employed on modern automobiles. The emitter of the transistor 118 is connected to ground and the collector is connected to one side of relay switch activating coil 132 and a diode 134. The other end of the coil and diode are connected to the DC voltage source 56. A relay switch 136 provides operating voltage to the low speed winding of wiper motor 44 through a two pole/two throw switch 138 which is manually positionable in either the auto position wherein the automatic wiper motor system is in control of the wiper motor or in the manual position wherein the normal vehicle wiper motor control controls the wiper motor. When in a manual operation mode, DC voltage is applied through a 680 ohm resistor 142 and a series LED 144. The term DC voltage or DC voltage source 56 throughout the discussion refer to the vehicle battery which can be 6 or 12 volts DC the negative pole of which is referred to as ground. The multiplexer 52 and 54 shown are cos/mos analog multiplexers typically of the type CD 4051 or an equivalent thereto. The inverter buffers 72 and 90-96 are type CD 4049 or equivalent. The dual up counter 80 is an CD 4520 or equivalent. And gates 84 and 86 and flip-flop circuit 82 are a CD 4096 or equivalent. The voltage comparators 60 and 66 are single dual voltage comparator circuit's CA 3290 or are two single equivalents or an equivalent dual unit. Transistor 118 is a 2N3569 or equivalent. Transistor 122 is a 2N3638 or equivalent. The wiper blade position sensor 20 can be an optical device, hall effect transistor,
110

magnetic switch, reed switch, waterproof switch, or the like which is activated by wiper contact or sensing. The various solid state circuits mentioned above have terminals or connections identified in the same manner as those specific circuits noted above and shown in the various drawing figures. It should be understood that equivalent circuits may have differently identified terminals or connections and would be connected to equivalent circuit connections in accordance with the circuit manufacturer's specifications. The resistors used throughout are typically one quarter watt carbon resistors of approximate value as noted. The potentiometer 64 is a one watt carbon type. The capacitors are chosen to operate safely at 12 volts DC. The LEDS operate on DC voltage and may have any desirable color or colors. BRIEF DESCRIPTION OF THE CIRCUIT OPERATION The multiplexer 52 and 54 are analog type multiplexers. The eight channels of each multiplexer are selected by a binary 0 through binary 7. The binary code is produced by the dual binary counter 80. The half of the binary counter that selects the multiplexer channels is clocked by the oscillator made up from inverters 72, the resistor 74; 76 and capacitor 78. If, for example, a water droplet is deposited across two adjacent conductive sensor strips 50, the multiplexer in its sequencing will select these conductive sensor strips. For the brief moment that these conductive sensor strips 50 are selected, there is a current pattern there between from the DC voltage source through resistor 51, through the multiplexers to the high side of capacitor 57 thereby charging capacitor 57. As the multiplexers switch, other pairs of conductive sensor strips 50 which have rain or moisture there between conduct there between in the same manner. Each current path thereby provided will increase the charge on capacitor 57. As the amount of rain or moisture intensity diminish the voltage applied to the capacitor 57 will further diminish due to the constant discharge through resistor 58 until a voltage level below the pre-selected voltage level required to operate the wiper motor will result. The voltage charge on capacitor 57 is continually compared with a preset voltage level on the positive inputs of voltage comparators 60 and 66. The type CA 3290 comparators shown are open-collector devices and require pull up resistors 68 and 70. Two threshold voltage levels for comparison are provided by the voltage divider comprising resistors 62, 63 and potentiometer resistor 64. When the voltage level at the inverting input of comparator 60 is more positive than the voltage level on its non-inverting input, its output becomes a logic "0". A logic "0" at the output indicates water present across sensor strips 50 sufficient to require wiper blade action. For the circuit to now produce a signal that activates the wiper motor 44, flip-flop circuit 82 must have proper inputs. The output from voltage comparator 60 provides an inputs. The output from voltage comparator 60 provides an input to the inverting input of the And gate 84 which must be a binary "0" and the other two inputs to the And gate 84 must be a binary " 1 ". One of the two inputs is always "1" since it is connected directly to the DC voltage source 56 and the other is initially a binary "1" until the wiper blades reach the wiper blade sensor position. The output of the And gate 84 is now binary 6'1'~ Under these conditions a binary "1" will appear at the non-inverting output Q of flip-flop 82 if the clock input to the flip-flop makes a transition from binary "0" to binary " 1" when the the Q3 output
111

of the first half of dual binary counter 80 makes a binary "09~ to binary " I " transition and if the output of And gate 86 is a binary "0". When the non-inverted output Q of flip-flop 82 is a binary "1" the transistor 118 will be biased on. Transistor 118 will conduct from emitter to collector and provide a return path for the relay switch activating coil 132. The diode 134 across the coil 132 is used to squelch the reverse electro motive force (EMF) produced by the coil field collapsing when the relay is de-energized. When the contacts of the relay switch make or close, the wiper motor 44 is activated. When the non-inverted output Q of flip-flop 82 is a binary "1" the inverted output thereof is a binary 66099, This inverted output removes the reset pulse from half of the dual binary counter 80 and the clock pulse is now provided from the other half of the same dual up counter. The outputs from one half of the binary counter supply inputs to buffer inverters through their associated resistor sequentially illuminating LEDs 98-104. This provides indication that the multiplexer is operative and a pleasurable light show for the vehicle occupants will be displayed on control portion 15B. When the wiper motor is activated, the wiper blade or blades will continually wipe across the sensor strips 50, removing the rain drop or drops that caused the prior wiper activation. The wiper action termination sequence is as follows. When the wiper blade or blades reach the wiper position sensor 20, the position sensor will produce a binary 64093 at its connection to the And gates 84 and 86. This is the only position of the wiper blade or blades that the automatic wiper motor control activation can make a decision to de-activate the wiper motor or not. This decision depends on the moisture level between the sensor strips 50 of the sensor 12 and the binary voltage level present at the output of the voltage comparator 60. If the output or voltage level of comparator 60 remains a binary "0" and a binary "0" to " I'd transition occurs at the clock input of the flip-flop 82, operation of the wiper motor will continue. If, on the other hand, drops have not reaccumulated across the sensor strips, the output of the voltage comparator 60 will change from a binary "0" to a binary " I " causing the output of the And gates 84 and 86 to provide a binary "0" to the input to flip-flop 82. Also under these conditions, the output of And gate 86 will be a binary "1" causing the noninverted output of flip-flop 82 to change from a binary "1" to a binary "0" when a binary "0" to "1" transition occurs at the clock input to flip-flop 82. At this time transistor 118, will be turned off which terminates the operating voltage to the wiper motor, ie. switch 136 returns to its normally open condition. The wiper motor will not normally stop when the wiper blade or blades are positioned in the middle of a sweep as the park switch associated with a conventional wiper motor will maintain motor operation until the wiper blade home position is reached. Once the wiper blade or blades start moving toward its home position, the wiper position sensor 20 will change from a binary "0" to a binary " I ". This binary "1" forces the output of And gate 86 to switch from a binary "1" to a binary "0" at the same time the other two inputs of And gate 84 are at a binary "1" causing the output of binary "0" at And gate 84. So now the output of the voltage comparator 60 depends on whether or not moisture has reaccumulated between the sensor strips 50 of sensor 12. If moisture re-accumulates after the decision to terminate wiper motor action has been made, the voltage comparator 60's output will change from a binary "1" to a binary "0" and with the conditions above being conductive, wiper motor action resumes in the hereinbefore explained manner. No interruption of wiper action will be observed under these conditions because of the action of the home-park switch. When the automatic controls of the invention terminate wiper motor action the inverted output of the flip-flop 82 will cause the dual up counter to reset, terminating the output to buffer/inverters 90-96 and thereby terminating the sequential illumination of LEDS 98-104.
112

When the voltage at the inverting input of the voltage comparator 66 is more positive than the voltage level from the DC voltage source through resistor 62, as set by potentiometer resistor 64 and resistor 63, the output of the voltage comparator 66 will change from a binary "1" to a binary "0". The presence of the binary "0" indicates that a high accumulation of moisture or water is present on sensor 12. This condition will cause transistor 122 to conduct from emitter to collector. This conduction provides a return path for the second wiper motor speed relay coil 126, closing the relay switch 130 associated therewith activating the conventional high speed windings of the wiper motor 44. Diode 128 serves the same purpose as the other diode 134 hereinbefore mentioned. The capacitor 116 and resistor 114 form a power-onreset for flip-flop 82 so that the wiper motor is off upon initial power up of the automotive wiper motor circuit. The power-on-reset occurs when the vehicle is started (ignition on) if the manual/automatic switch 138 (a dual pole double throw type) has previously been moved from the manual to automatic position shown. If the vehicle has previously been started with switch 138 in the manual position, selecting the automatic mode of switch 138 will cause a power-on-reset to occur. The switch removes the DC voltage source 56 from the wiper motor circuit when the switch 138 is in the manual mode and also when the manual mode is selected the automatic portion of the switch 138 opens causing the current path to the wiper motor to be open. The automatic wiper control circuit is now removed from the wiper motor's normal circuit. Moving the switch 138 from auto to manual causes LED 144 to illuminate. Throughout the above discussion an automobile windshield wiper motor system has been used to describe an embodiment of this invention. It should be understood that the automobile environment is not intended to limit the use of the invention as obviously, the invention can be employed in conjunction with any window wiper system employing a motor, linkage and blade(s). CONCLUSIONS 1. An automatic wiper motor control system for oper- . ating a window wiper motor which operates at least one wiper blade to and fro across window for removing moisture from the area which it sweeps, said motor having a park circuit means for returning said wiper blade to a home location when said wiper motor action, is terminated at other than the wiper blade home location comprising: a voltage source; a moisture sensor, said moisture sensor comprising a plurality of spaced apart exposed conductive strips: positioned within an area of the sweep of said at least one wiper blade; a voltage storage means; a scanning circuit for sequentially connecting adjacent pairs of said conductive strips, one of said pair to said voltage source and the other of said pair to said voltage storage means; a wiper motor operating circuit; a voltage sensing means connected between said voltage storage means and said wiper motor operating circuit, said voltage sensing means activates said wiper motor operating circuit when the voltage level of said voltage storage means exceeds a preselected voltage level; and a wiper position sensor means positioned along the sweep of said wiper blade and influenced by the blade passing there across for activating the operation of said voltage sensing means, whereby a determination is made by said automotive wiper motor control system to operate said wiper motor or terminate said operation.

113

2. The invention as defined in claim 1 wherein said wiper motor is multi-speed. 3. The invention as defined in claim 1 wherein said voltage source is a storage battery. 4. The invention as defined in claim 1 wherein said scanning circuit comprises a pair of multiplexer circuits each of which is operated at a common frequency. 5. The invention as defined in claim 1 wherein said voltage sensing means comprises a means to constantly remove a portion of the voltage stored therein. 6. The invention as defined in claim 2 wherein said voltage sensing means comprises means for operating said multi-speed wiper motor at one speed when the voltage in said voltage storage means is above a first preset level and at an increased speed when the voltage in said voltage storage means exceeds a second preset level. 7. The invention as defined in claim 6 wherein the first preset level of voltage which operates said multispeed wiper motor at said one speed is adjustable. 8. The invention as defined in claim 6 wherein the second preset level of voltage which operates said multi-speed wiper motor at said increased speed is adjustable. 9. The invention as defined in claim 1 additionally comprising visual means for providing indication of operation of said scanning circuit. 10. The invention as defined in claim 9 wherein said visual means includes a plurality of LEDS. 11. The invention as defined in claim 10 wherein said LEDS all illuminate in the same color. 12. The invention as defined in claim 10 wherein some of said LEDS illuminate in different colors than others thereof. 13. The invention as defined in claim 2 additionally comprises a switch for removing said automatic wiper motor control system from control of said multi speed wiper motor and an LED connected in conjunction therewith for a visual indication of the removal of said automatic wiper motor control system from control of said multi-speed wiper motor. 14. The invention as defined in claim 1 wherein said park circuit means continues to operate said wiper motor when said wiper blade across said position sensor causes said automatic wiper motor control to terminate operation of said wiper motor.

**************

114

PARKING AIR CONDITIONING SYSTEM

ABSTRACT An automobile air conditioning system for controlling the inside temperature of an automobile to maintain the inside temperature in a comfortable range or to protect the contents of the automobile from becoming overheated on excessively hot days or to prevent freezing on cold days when the automobile is parked or not in use is disclosed. This project relates generally to automobile air conditioning systems and specifically to systems for controlling the inside temperature of an automobile to maintain the inside temperature in a comfortable range or to protect the contents of the automobile from becoming overheated on excessively hot days or to prevent freezing on cold days. Automobile operators and passengers in warmer climates and on unusually hot summer days in most climates experience considerable discomfort when they enter an automobile which has been parked in the hot sun or in an uncooled garage during hot weather. Air conditioning technology for automobiles during operation is a well-developed art, and automobile air conditioners are very common. The most common automobile air conditioners are driven directly from the automobile engine by means of a belt and pulley or some other mechanical linkage. Some automobile air conditioners are driven by an electric motor, although electrically driven units are not suitable for prolonged use except when the automobile engine is running because of the high energy consumption of such units. Automobile air conditioners of the conventional type may be described as "brute force" systems, because little or no effort is made to prevent heat transfer in or out of the automobile, the emphasis being on large and powerful air conditioning units.Various efforts have been made to use solar energy, \ but such units have not gained general acceptance. There are many types of sunshades, reflection devices, etc., to control or prevent the sun from shining through a window, or to provide for entry of light with some degree of thermal insulation Temperature control devices for automobile and aircraft compartments, etc., are in common use. An air conditioner powered by compressed air which could operate for a period independently of the automobile engine, and which includes a retractable shade over the windshield and tinted windows to reduce solar heat in the car. It is common practice in warmer climates to leave a small opening at the top of the windows to permit some circulation of air and the escape of heated air from an automobile parked in a hot location.
115

This practice is of little value and introduces some security risk as it is possible to open most automobile doors with a wire if access can be gained through a window.

SUMMARY A system is provided for maintaining a reasonably low inside temperature in an automobile parked in the full sun and at the same time is in a hot ambient atmosphere, for a period of 6 or more hours. In most instances, it is sufficient that the system operate for from about 2 to about 8 hours, the precise operating time is not, however, a critical factor. The invention comprises a combination of insulation means, solar reflection means, and battery powered refrigeration means. The insulation means prevents viewing of objects left inside car, and thus provides for greater security. Indicia, such as the owners name, telephone number, etc., a family coat of arms, advertisements, etc., may be placed on the insulation means to be viewed by those who pass by the parked automobile. The areas to be insulated include top, sides, doors, bottom, and all windows as well as the fire wall and trunk wall. All non-window areas will require a thermal insulation about 15 to 20 mm thick. The front and rear windows will be insulated with 15 mm thick pads which are stored in the roof compartment of the car. These pads may be pulled down by and or driven by motors to slide down in place over the windows when the car is locked and a command to do so has been given by the driver prior to or after exiting the car. The outside surface of the pads would be highly reflective to sunlight. The side window insulating pads are preferably stored in the doors and slid upwards in a manner similar to the windows but inside the windows. Mechanical or electrical drives for moving the window insulating pads to cover the windows may be provided, or the pads may be moved by hand. For example, these pads may be moved by motors set in motion when the doors were locked and by permission of the driver's command given to the automobile's computer upon leaving the car. A small auxiliary compressor driven by a battery operated motor supplies the refrigeration to make up for the heat leakage through the insulation. In cold climates, a reverse-cycle heat pump may be used to make up for heat loss through the pads when the car is parked. Preferably, all temperature control functions are under the control of the automobile operating computer, which is standard on larger automobiles, or from a special microprocessor, having an input from a thermal transducer inside the car and, if desired, a thermal transducer which measures the exterior of the car. This project is an improvement in automobiles which comprise a body defining a passenger compartment, window openings and door openings, doors covering the door openings defining window openings in the doors, windows covering the window openings in the body, and an electric storage battery. The improvement is embodied in a thermal control system for controlling the temperature inside the body during periods of parking. The thermal control system comprises: insulating means comprising a plurality of insulating pads, the insulating pads being moveable, respectively, from a position covering the respective windows in the body and the doors to a position revealing said windows to permit vision there through from the passenger compartment; refrigeration and/or heating means for selectively cooling or heating the passenger compartment during periods of periods of parking, and control means for connecting the refrigeration and/or heating means to the storage battery for powering and
116

operating the refrigeration and/or heating means in accordance with predetermined control criteria. The insulating means is so constructed and disposed over the windows as to limit the heat flow into and out of the passenger compartment to the exterior of the automobile to no greater than a predetermined rate when the exterior of the car is at temperatures above about 80° F. and no greater than about 130° F. The refrigeration and/or heating means is so constructed and designed as to be capable, when connected to the battery means, of introducing cooling or heating into the passenger compartment at about said predetermined rate. The insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration and/or heating means are, respectively, such that the refrigeration and/or heating means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80° F. to about 90° F. when the temperature outside the automobile is from above 90° C. and up to about 130° C. for a period of from about two to about eight hours without using more than about one-half of the electric energy capable of being stored in the battery, and of rnaintaining the temperature in the passenger compartment at a temperature of from about 32° F. to about 50° F. when the temperature outside the automobile is from below 30° F. and above about—30° F. for a period of from about two to about eight hours without using more than about one-half of the electric energy capable of being stored in the battery. Preferably, the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration and/or heating means being, respectively, such that the refrigeration and/or heating means is capable of maintaining the temperature in the passenger compartmene at a temperature of from about 80° F. to about 90° F. when the temperature outside the automobile is from above 90° C. and up to about 110° C. for a period of from about two to about eight hours without using more than about one-fourth of the electric energy capable of being stored in the battery and of maintaining the temperature in the passenger compartment at a temperature of from about 35° F. to about 50° F. when the temperature outside the automobile is from below 30° F.,and above about—30° F. for a period of from about two to about eight hours without using more than about one/fourth of the electric energy capable of being stored in the battery. In an even more preferred embodiment, the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration and/or heating means being, respectively, such that the refrigeration and/or heating means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80° F. to about 90° F. when the temperature outside the automobile is from above 90° C. and up to about 110° C. for a period of from about two to about eight hours without using more than about one-tenth of the electric energy capable of being stored in the battery and of maintaining the temperature in the passenger compartment at a temperature of from about 35° F. to about 50° F. when the temperature outside the automobile is from below 30° F. and above about—30° F. for a period of from about two to about eight hours without using more than about one-tenth of the electric energy capable of being stored in the battery.

117

DETAILED DISCRIPTION

FIG. 1 is a generalized schematic depiction of an automobile incorporating the fundamental features of this invention. It is to be recognized that the invention has universal applicability to all automobiles, and that the particular style of the automobile, the number and size of the windows, etc., are not particularly significant with respect to the applicability of the invention, since the invention can be adapted to virtually any automobile style by those having ordinary skill in the design of automobiles, based upon the disclosure herein.
118

The automobile 100 is depicted as being exemplary and that it has a windshield 102, back window 104, and two side windows 106 and 108. The automobile is shown in partial cutaway, and partial cross-section, and, therefore, does not shown the two windows opposite to the reader's side of the automobile which, of course, would be treated in exactly the same way as described hereinby the user and pulled down in suitable tracks or other supports, or simply held by its own rigidity, to cover the windshield. When the insulating pad 112 is in its down position covering the windshield, the dead-air space it leaves behind will still serve to insulate the roof in that area. Similarly, the insulating pad 114 may be grasped and pulled down to cover the back window. Insulating pads 116 and 118 may be moved by way of handles 126 and 128 to the closed position where they cover, respectively, windows 106 and 108. In this embodiment, the panels extend slightly above the edge of the window opening, and the user simply graspsOne of the features of this invention is the provision of an insulating pad 112, the features of which will be described in greater detail, which is movable between two of more positions, one position of which is to cover the windshield to reduce the amount of energy flow in or out of the passenger compartment through the windshield. A comparable insulating pad 114 is also movable at least from a position covering the back window to a position not covering the back window, for reducing the heat of energy in or out of the automobile passenger compartment through the back window. Insulating pads 116 and 118, respectively, are movable from a position covering window 106 and, respectively, 108. The pads 116 and 118 are shown partially covering the respective windows. Smaller windows, such as shown at 117, may be formed of double-pane dark glass with an air space between the panes. The recessed location (now an insulating dead-air space) of the insulating panel 112 is shown at 122, and a comparable dead air space for storing the insulating pad 114 is shown at 124. Insulation, such as shown at 123, may be provided where a dead air space is not provided. The insulating pads or panels 112 and 114 will, in a simplified embodiment, extend a short distance, approximately one inch, above the floor of the roof compartment, the roof compartment being defined by the outer roof and the inner lining of the car. In this manner, the insulating pad 112 can be grasped the protuberances which form the handles 126 and 128 and slide the panels in the up position or in the down position. The panels may be held in the up position simply by friction in the slide or by some other mechanism. Since the precise structure and method of supporting the insulating panels is not critical to this invention, and because the method of moving the insulating pangs to a position closing the windows or to a position wherein the panels are recessed and the windows are exposed is not critical, the mode described is simplified to show the simple manual moving of these insulating panels from one position to the other. There are, of course, great many moving mechanisms which may be used to move a panel from one position to another. With respect to the side windows, for example, a duplicate of the mechanism by which the windows are rolled up and down, as attached to and applied to the movable insulating panels, could conveniently be used. Similarly, an electrical, hydraulic or mechanical drive can be provided to move the panels to cover the windshield and the back window, as desired. The automobile with will, as is conventional, have a door lock, indicated at 132, and, in accordance with this invention, will be provided with an auxiliary lockswitch 134 for setting the automobile thermal control system into operation after locking the car. In systems in
119

which motor, air or hydraulic drives are provided for moving the panels, or equivalent films, etc., the lockswitch will actuate these drive mechanisms and the compressor system either instantaneously or on a timed schedule. Referring now to FIGS. 1A, 1B, and 1C, alternative and equivalent panels or panel equivalents are depicted. Inside the conventional safety glass 136, held in place by the window frame 148, the panel may comprise a polymeric foam or other flexible insulation 138, as shown in FIG. 1A, a spaced-layer structure 142 which has two, or more, layers held in spaced apart relationship with dead air between them, as shown in FIG. 1B, or a membrane 144 which may be rolled or otherwise retracted and may be hod in position spaced from the glass to confine a dead air space between the membrane and the window. Polycarbonate films and Mylar films, which may be darkened and/or coated with a thin layer of reflective material, e.g. aluminum or chromium, to reflect or absorb light may be used as the membrane 144.

FIG. 2-A diagrammatically shows how the system operates in summer as a cooler, and FIG. 2B diagrammatically shows operation in winter as a heater of the passenger compartment. The alternator ALT, rectifier R. voltage regulator R. and storage battery B. are shown as in any standard American car. The alternator is, of course, on only when the engine is running and drives it. T is a timer, and C is an electronic or electromechanical controller, including thermocouples or thermistors T1 and T2, which senses the temperatures at T1 inside the passenger compartment, and at T2 in the ambient air. The timer and controller, according to setting determined by the operator, the electric motor M is turned on, is powered by the battery B. and drives the compressor COMP of the refrigerator/heat-pump system. Refrigeration fluid flow directions are shown by the arrows. Electromechanical actuators (not shown) turn the valves V to the directions indicated for either cooling the passenger compartment as shown in FIG. 2A, summer operation, or heating it as shown in FIG. 2B, winter operation. In summer operation, the hot compressed fluid is cooled by the outside air and then throttled through the expansion valve EV so as to evaporate in the coils inside the passenger compartment. The gas is returned to the compressor as in any normal refrigeration system. The amount of heat removed from the passenger compartment is equal to the mechanical energy supplied to the compressor by the motor times the "coefficient of performance" (C.O.P.) of the refrigerator. In winter operation, the valves V are turned the other direction as shown in FIG. 2-B. In this case, the hot fluid from the compressor is cooled inside the passenger compartment and so heats it. The fluid is then expanded through the expansion valve EV where it evaporates in the cold outside heat exchanger and absorbs heat from the outside air around it. It is this heat
120

which is pumped into the passenger compartment. Again, the heat pumped is the mechanical energy times the C.O.P. For typical refrigerants and refrigeration cycles the C.O.P. is between 4 and 5, and is dependent on the temperature differences involved. The operation of the system may be varied considerably to meet particular needs; however, the following is a typical pattern of operation in a warmer climate where cooling of the interior of the automobile is desired. The placement of the components of the system depicted in FIG. 2 is not critical, except that the evaporator of the air conditioner or condenser of the heat-pump must be in or in thermal communication with the passenger compartment of an automobile. The temperature sensor T1 must also be in or in thermal communication with the passenger compartment of an automobile and, if used, the temperature sensor T2 must be outside the car or in thermal communication with the temperature outside the car. The other components may be placed anywhere it is convenient. Typically, of course, the conventional alternator and voltage regulator and battery system would be used. The motor and compressor for the air conditioner may be located in the engine compartment, in the luggage compartment, or elsewhere as may be desired. When the operator desires to park the car and leave it in a hot place, for example, in bright sun or in a hot garage, etc., in a warmer climate, the operator may elect to use the invention to great advantage. The operator would cover the windows with the insulating pane^ls^9 whereas the panels 112 and 114 would be moved, manually or by suitable drive means, to cover the windshield 102 and the back window 104, respectively. Similarly, either manually or by suitable mechanical or electrical or other drive mechanism, the panels 116 and 118 are moved upwardly to cover the windows 106 and 108 respectively. As will be discussed in considerable detail hereinafter, this feature of the invention is absolutely essential for the success of the invention, as it is irnpractical, in a hot climate, to provide a battery-operated air conditioner of sufficient capacity to cool a car without insulating the windows and walls to prevent the excessive transfer of thermal energy through the windows and walls. The controller may be the car's main computer, which is now standard in most larger automobiles, or the controller may be a special microprocessor. The design and constructions of microprocessors and computers for turning circuits on and off, etc., is well known and not, per se, pare of the invention. Through a suitable controller, the operator may choose to maintain the temperature of the interior of the automobile between prescribed limits, or at a prescribed temperature. Alternatively, the operator may select a particular time for the air conditioner to turn on and cool the car before the operator's return. If, for example, the operator plarmed to be away from the car for seven or eight hours, it would not be necessary, in many instances, to maintain the interior temperature of the automobile at a comfortable level for the entire period. In that case, at an appropriate time before the expected return of the operator, the controller would turn the air conditioner on and bring the temperature of the interior of the passenger compartment down to a comfortable level by the time the operator returned. If, however, there are perishables or other materials, such as vegetables or candy, etc., in the car which might be damaged by very high temperatures, the temperature in the passenger compartment may be maintained at a single temperature during the entire absence of the operator.

121

In colder climates, the mode of operation is essentially the same, except that instead of turning an air conditioner on to cool the car, the system is automatically changed to reversecycle heat-pump to warm the car, either at a preset time to warm the car for the operator's return, or to maintain the temperature in the car above a certain preset temperature at all times during the operator's absence. There are certain important criteria which must be met in order for the invention to function and have practical utility. The overriding consideration is that the energy consumed by the air conditioner or the reverse-cycle heater must not exceed the reasonable capacity of the automobile battery, either a conventional battery or an expandedcapacity battery, leaving ample reserves for starting and operating the automobile at the end of the expected period of absence of the operator. As the cycle-life of a storage battery is a strong function of the depth to which it is discharged, it is important to limit the discharge amount. Also, certain battery constructions are better than others if deep-discharges are necessary. This overriding requirement cannot be met without providing suitable insulation over the windows of the automobile through which much of thermal energy flows. It is presumed, and necessary, that the automobile compartment be suitable insulated; however, the provision of suitable insulation throughout the remainder of the car, excluding the windows, is a conventional and easily achieved goal. There is a particularly critical relationship between the amounts of the insulation provided over the windows, the size of the air conditioner or heater, and the capacity of the battery which must be met. These considerations have been studied, and the data are depicted in FIGS. 3 through 10.

122

Referring first to FIG. 3, the temperature inside an automobile passenger compartment as a function of time is plotted, using the following constants and criteria. The outside temperature is 110° F. The initial inside temperature in the automobile passenger compartment is 70° F. The data in FIGS. 3, 4 and 5 are also based upon a covering of urethane insulation having a thickness of 20 mm, as will be described, over the windows. The four curves indicate the inside temperature as a function of time for four different sizes of automobiles, having different inside thermal mass values of, respectively, 50 kilograms per degree C (kg/°C.), 100 kg/°C., 150 kg/°C. and 200 kg/°C. FIG. 4 depicts the tempcrature as a function of time in a passenger car as described with respect to FIG. 3, but with the addition of varying amounts of refrigeration, the respective curves depicting, from the top, zero refrigeration, 50 watts of refrigeration energy input to the passenger compartment, 100, 150, 200 and 250 watts of refrigeration input to the passenger compartment, respectively for the curves shown in FIG. 4. It may not be economical or necessary that the air conditioner input to the passenger compartment be sufficient to maintain the temperature at the starting
123

temperature, i.e. 70° C., as indicated by the 250-watt refrigeration input line, and the use of this amount of power would be prohibitive with conventional battery capacity. Using suitable insulation, and suitably efficient air conditioning units, however, it is entirely feasible to maintain the temperature at under 90° F. and even possible to maintain the temperature under 80° F., assuming an outside temperature of l 10° F., for a long period of time. In FIG. 4, as the curves clearly depict, the maintenance air conditioner of this invention is turned on, and of course the insulation is in place, at the time the operator leaves the car and operates for a period of 6 hours, the assumed return time of the operator.In FIG. 5, a more efficient mode of operation is depicted, where it is not necessary to maintain the temperature of the car during the entire period of a long absence. The initial curve I in FIG. 5 depicts the increase in temperature inside the passenger compartment for a period of 4 hours at which time the timer T. as shown in FIG. 2, turned the air conditioner on. The curves after the initial curve I depict the cooling of the temperature assuming levels of 50 through 250 watts of refrigeration input to the passenger compartment. Clearly, unless constant maintenance of the interior temperature is vital, this mode of operation is far more efficient if the expected time of return is reasonably certain.

FIGS. 6, 7 and 8 are analogous to FIGS. 3, 4 and 5, except that in FIGS. 6, 7 and 8, the data result from an initial temperature of 70' F. and an outside temperature of O' F. with the addition of heat to the passenger compartment, rather than air conditioning u was the case in the data depicted in the graphs of FIGS. 3, 4 and S.

124

As we described previously, the automobile windows are insulated with 20 mm of urethane insulation, the nature of which will be described hereinafter. The curves in FIG. 6 depict the thermal mass of the inside of the automobile in kilojoules per degree centigrade (Icg/'C.), at levels of 50, 100, 150 and 200 kg/'C. The curves in FIG. 7 depict the inside temperature of the automobile with differing levels of heat input, from zero through 300 watts of heat introduced into the passenger compartment, being depicted by the various curves, starting at the bottom at zero watts of heat input with curves showing the input of 60, 120, 180, 240 and 300 watts. It should be noted that any insulating panels of generally comparable insulating value, such as, for example, hollow or expanded polystyrene-filled panels sealed at the edges to prevent convection may be used in place of the closed-pore urethane which hue been described as preferred. The exact composition or construction of the insulation is not critical, so long as it functions in the manner described. As in FIG. 4, the introduction of heat into the passenger compartment was begun at zero time, at the time the operator left the car, with a presumed return of 6 hours later. FIG. 8, as in FIG. 5. depicts the operation of the system in a more efficient manner, the initial curve I being the temperature drop of the passenger compartment for the first 3 hours at which time the heater is turned on resulting in the temperatures shown by the plurality of curves on the right-hand portion of the graph, the respective curves depicting introduction of 60', 120', 180~, 2406 and 300' watts of heat energy introduced into the passenger compartment. The data set forth in graphical form in FIG. 3 through 9 were bused upon the following foundational data and values. A foam polyurethane insulating pad was talcen as a buis for calculating the insulting value of the insulating pads over the windows, windshiels, and the rear window. The particular foam urethane referred to was manufactured by the Upjohn Company and had a thermal conductivity of 0.022 watt per meter degree centigrade, or 2.02X 10-4 watt/cm'C. Now obviously the particular lain of insulation is not critical, so long as it has a thermal conductivity low enough to provide the necessary insulation for preventing excess thermal flow through the windows of the car. Polystyrene has a lower thermal conductivity, but is not structurally as strong and easily handled as polyurethane foamed insulation. As a model for the calculations, a four-door passenger sedan, having a window surface area of 4,257 square inches was taken for reference. The surface of the top, the two sides, the engine fire wall, the rear and the bottom were totalled to 17,963 square inches. A maximum temperature differential for which compensation would be made was selected at a AT of 40° F. Or 22° C. Using average efficiency of conversion from electric energy to cooling energy, and assuming an automobile battery storage capacity of 150 ampere hours, it was determined that thermal energy input to or extraction from the passenger compartment of the automobile could be as high as 300 thermal watts without unduly discharging the battery over a period of up to 6 to 8 hours of absence of the operator. The calculations resulted in the data which are shown graphically in FIGS. 3 through 9 which establish that it was theoretically possible to achieve the desired goal, namely maintaining a reasonably comfortable temperature inside the passenger compartment of the automobile at either maximum expected or minimum expected reasonable exterior temperatures. As the data in the figures show, it would not be practical to compensate for all possible maximum and minimum temperatures and maintain the passenger compartment at a temperature of a
125

comfortable 70° F.; however, the desired comfortable temperature can be approached within reasonable limits using up to 300 thermal watts of energy. If auxiliary storage capacity for electrical energy is provided by way of large industrial batteries or auxiliary batteries and generating power, it would be possible to achieve a 70°passenger compartment temperature after a reasonable period of time under virtually any possible climatic conditions. It was not considered necessary, however, to design for the most extreme possible circumstances. In order to determine whether the calculations previously described were sufficiently valid as applied to an actual automobile, an experiment was performed using a 1982 Oldsmobile Delta 88 as the test object. A 225watt heater (two flood lamps) was mounted inside the car so as to shine on the roof. The automobile was parked in a closed garage, and the temperature inside the car and inside the garage were measured as a function of time. In one case the automobile was as manufactured (nothing added). In the second case, one inch of polyurethane foam insulation was mounted on the inside surface of all of the windows. The areas of various automobile surfaces are as follows:

Air-solid interfaces: h=0.0012+0.00014 V watt/cm^2deg. C.; where V is the wind velocity in MPH.

The overall thermal resistance of the compartment walls "as is" equals 0.0346 deg. C/watt. This number is simply the temperature difference generated in steadystate divided by the heat power employed. With foam on all windows, the thermal resistance was increased to 0.0617 deg. C/watt, which is a 78% increase and indicates that 44% of the heat conduction involved, flows through the windows. FIG. 9 is a time-plot. The curve marked by x's depicts the inside temperature of the garage. The curve marked by closed squares depicts the inside temperature of the Oldsmobile when a 225-watt heater lamp was placed inside with the windows closed. The sharp break in the curve at 382 minutes occurred when the power was turned off.The thermal time constant for this case is 55 minutes. FIG. 10 is a similar plot with one inch of foam pad added to the inside surface of all the window areas. At the time indicated by the letter A, an additional one inch of foam pad was placed over the entire top of the car. At time B. the heater was turned off. The thermal time constant for this case is 130 minutes.

126

Wl=Glass thickness=0.4 cm W2=Polyurethane foam thickness=2.54 cm W3=Plastic thickness inside safety glass=0.085 cm h = Air-film coefficient =0.00124 watts/cm^2deg. C. k2=Foam conductivity=0.00025 watts/cm deg. C. kl=Glass conductivity=0.0105 k3 = Plastic conductivity = 0.002 R=Thermal resistance for an area of A square centimeters. AXR=2(1/h)+W1/kl+W2A~2+W3/k3 deg. C/watt C=Conduction= I/R (Note that for no foam, W2=0.) Measured total automobile compartment wall conduction including uninsulated windows: CO=28.9 watts/deg. C. Measured with insulated windows: Cl = 16.2 watts/deg. C. Calculated uninsulated window conduction= 14.8 watts/deg. C. Calculated insulated window conduction=2 watts/deg. C.

127

The body thermal conductance is defined here as the conductance exclusive of window areas. Heat Balance: Body thermal conductance 28.9 - 14.8=14.1 watts/deg. C. Body thermal conductance from 16.2 - 2=14.2 watts/deg. C. This agreement shows how well the actual results agree with the theory. RESULTS For an outside temperature of 110 deg. F., and an inside temperature of 80 deg. F., the heat flow with no foam is calculated as 497 watts. With foam on the windows alone it would be 270 watts. This could be reduced to 200 watts if a bit more insulation was added to the body areas. In the case of the Oldsmobile, the roof already is insulated with a foam pad which is about 8 mm thick. This should be increased to at least 15 mm, and an insulating pad should be added to the floor, under the carpet, example, or on the underside of the floor as an insulating and rust preventing layer, or in any other convenient manner. The air-space created by adding retractable window insulators to the doors will suffice as additional door insulation. With these criteria met, a refrigeration power of 200 watts derived from 40 watts of electric power and a refrigeration coefficient of performance (C.O.P.) of 5 will be sufficient for even the most rigorous outside conditions. Battery Power Considerations Forty watts at 12 volts is a drain of 3.33 amps. For a total elapsed time of 2 hours, this would drain 6.7 amphours. For a fully charged battery, this is less than 10%. To replace it would require a driving time of about 15 minutes. There is no good reason to keep the car cool for long periods if the time of departure is approximately known. In this case the automobile computer would be told of the desired departure time, and it would turn on the auxiliary refrigeration compressor at the proper time to get the car ready for occupancy. The panels are, preferably formed of closed-pore foamed polymer, such as^9 for example a polyurethane. The panels are preferably opaque, thereby preventing persons outside the automobile from seeing articles in the automobile passenger compartment. The panels may of any suitable insulating construction and material and may, for example, comprise spaced apart, rigid, rugged surface sheets and an edge seal defining dead air insulating space there between or of spaced apart, rigid, rugged surface sheets and an edge seal and a very high insulating value expanded polymer insulating layer there between such as, for example, expanded polystyrene. A thin layer of a tough polymer such as a polycarbonate sandwiching expanded polystyrene is an example of the latter type of panel construction. With suitable panels of sufficient insulating value, in most cases which will be encountered by drivers, no refrigeration will probably be needed, as the sun-blockage alone together with the insulation will suffice to keep the car cool or hot enough for the normal passenger.

128

CONCLUSION 1. In an automobile which comprises a body defining a passenger compartment, window openings and door openings, doors covering the door openings defining window openings in the doors, windows covering the window openings in the body, and an electric storage battery, the improvement where in the automobile further comprises a thermal control system for controlling the temperature inside the body during periods of parking, the thermal control system comprising: (a) Insulating means comprising a plurality of insulating means, the insulating means being moveable, respectively, from a position covering the respective windows in the body and the doors to a posit tion revealing said windows to permit vision there through from the passenger compartment; (b) Refrigeration means for cooling the passenger compartment during periods of parking; (c) control means for connecting the refrigeration means to the storage battery for powering and operating the refrigeration means in accordance with predetermined control criteria; the insulating means being so constructed and disposed over the windows as to limit the heat flow into and out of the passenger compartment to the exterior of the automobile to no greater than a predetermined rate when the exterior of the car is at temperatures above about 80~ F. and no greater than about 130~ F.; the refrigeration means being so constructed and designed as to be capable, when connected to the battery means, of introducing refrigeration cooling into the passenger compartment at about said predetermined rate; the insulation value of the insulating means, the dectrical storage capacity of the storage battery and the coefficient of performance of the refrigeration means being, respectively, such that the refrigeration means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80' F. to about 906 F. when the temperature outside the automobile is from above 90~ F. and up to about 130~ F. for a period of from about two to about eight hours without wing more than about one-half of the electric energy capable of being stored in the battery. 2. The thermal control system of claim 1 wherein the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration means being, respectively, such that the refrigeration means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80° F. to about 90~ P. when the temperature outside the automobile is from above 90~ F. and up to about 110~ F. for a period of from about two to about eight hours without using more than about one-fourth of the electric energy capable of being stored in the battery. 3. The thermal control system of claim 1 wherein the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration means being, respectively, such that the refrigeration means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80~ F. to about 90' F. when the temperature outside the automobile is from above 90' F. and up to about 110~ F. for a period of up to about six hours without using more than about one-tenth of the electric energy capable of being stored in the battery.

129

4. The system of claim 1 wherein a second door-lock on the front doors of the vehicle enables the operation of the insulation means to be set into motion. 5. The system of claim 4 wherein the insulating means automatically retract when the doorlock is opened with a key, or an inside switch. 6. The system of claim 1 wherein the insulating means are easily retracted manually in case of system failure. 7. The system of claim 1 wherein the insulating-hiding from view means are partially deployed at the command of the operator. 8. The system of claim 1 wherein automatic deployment of the front-window insulating means is prevented by a fail-safe system when the automobile is in motion. 9. In an automobile which comprises a body defining a passenger compartment, window openings and door openings, doors covering the door openings defining window openings in the doors, windows covering the window openings in the body, and an electric storage battery, the improvement where in the automobile further comprises a thermal control system for controlling the temperature inside the body during periods of parking, the thermal control system comprising: (a) insulating means comprising a plurality of insulating pads, the insulating pads being moveable, respectively, from a position covering the respective windows in the body and the doors to a position revealing said windows to permit vision therethrough from the passenger compartment; (b) heating means for heating the passenger compartment during periods of periods of parking; and (c) control means for connecting the heating means to the storage battery for powering and operating the heating means in accordance with predetermined control criteria; the insulating means being so constructed and disposed over the windows as to limit the heat flow into and out of the passenger compartment to the exterior of the automobile to no greater than a predetermined rate when the exterior of the car is at temperatures below about 30° F. and no lower than about—30~ F.; the heating means being so constructed and designed as to be capable, when connected to the battery means, of introducing heat into the passenger compartment at about said predetermined rate; the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the heating means being, respectively, such that the heating means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 32~ F. to about 50° F. when the temperature outside the automobile is from below 30° F. and above about—30° P. for a period of from about two to about eight hours without using more than about one-half of the electric energy capable of being stored in the battery. 10. The thermal control system of claim 9 wherein the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration means being, respectively, such that the refrigeration means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 35° F. to about 50~ F. when the temperature outside the automobile is from below
130

30° F. and down to about—30° F. for a period of from about two to about eight hours without using more than about one-fourth of the electric energy capable of being stored in the battery. 11. The thermal control system of claim 9 wherein the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration means being, respectively, such that the refrigeration means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 35° F. to about 50° F. when the temperature outside the automobile is from below about 30° F. and down to about—30° F. for a period of up to about six hours without using more than about one-tenth of the electric energy capable of being stored in the battery. 12. In an automobile which comprises a body defining a passenger compartment, window openings and door openings, doors covering the door openings defining window openings in the doors, windows covering the window openings in the body, and an electric storage battery, the improvement where in the automobile further comprises a thermal control system for controlling the temperature inside the body during periods of parking, the thermal control system comprising: (a) insulating means comprising a plurality of insulating pads, the insulating pads being moveable, respectively, from a position covering the respective windows in the body and the doors to a position revealing said windows to permit vision therethrough from the passenger compartment; (b) refrigeration and heating means for selectively cooling or heating the passenger compartment during periods of periods of parking; and (c) control means for connecting the refrigeration and heating means to the storage battery for powering and operating the refrigeration and heating means in accordance with predetermined control criteria; the insulating means being so constructed and disposed over the windows as to limit the heat flow into and out of the passenger compartment to the exterior of the automobile to no greater than a predetermined rate when the exterior of the car is at temperatures above about 80° F. and no greater than about 130° F.; the refrigeration and heating means being so constructed and designed as to be capable, when connected to the battery means, of introducing cooling or heat into the passenger compartment at about said predetermined rate; the insulation value of the insulating means^9 the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration and heating means being, respectively such that the refrigeration and heating means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80° F. to about 90° F. when the temperature outside the automobile is from above 90° C. and up to about 130° C. for a period of from about two to about eight hours without using more than about one-half of the electric energy capable of being stored in the battery and of maintaining the temperature in the passenger compartment at a temperature of from about 32° F. to about 50° F. when the temperature outside the automobile is from below 30° F. and above about— 30° F. for a period of from about two to about eight hours without using more than about onehalf of the electric energy capable of being stored in the battery. 13. The thermal control system of claim 12 wherein the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration and heating means being, respectively, such that the
131

refrigeration and heating means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80° F. to about 90° F. when the temperature outside the automobile is from above 90° C. and up to about 110° C. for a period of from about two to about eight hours without using more than about one-fourth of the electric energy capable of being stored in the battery and of maintaining the temperature in the passenger compartment at a temperature of from about 35° F. to about 50° F. when the temperature outside the automobile is from below 30° F. and above about—30° F. for a period of from about two to about eight hours without using more than about one-fourth of the electric energy capable of being stored in the battery. 14. The thermal control system of claim 12 wherein the insulation value of the insulating means, the electrical storage capacity of the storage battery and the coefficient of performance of the refrigeration and heating means being, respectively, such that the refrigeration and heating means is capable of maintaining the temperature in the passenger compartment at a temperature of from about 80° F. to about 90° F. when the temperature outside the automobile is from above 90° C. and up to about 110° C. for a period of up to about six hours without using more than about one-tenth of the electric energy capable of being stored in the battery and of maintaining the temperature in the passenger compartment at a temperature of from about 35° F. to about 50° F. when the temperature outside the automobile is from below 30° F. and above about—30° F. for a period of up to about six hours without using more than about one-tenth of the electric energy capable of being stored in the battery. 15. The system of claim 12 wherein the pads are formed of closed-pore foamed polymer. 16. The system of claim 15 wherein the polymer is a polyurethane. 17. The system of claim 12 wherein the pads include indicia which relate to the identity of the owner. 18. The system of claim 12 wherein the pads are opaque^9 thereby preventing persons outside the automobile from seeing articles in the automobile passenger compartment. 19. The system of claim 12 wherein the pads comprise spaced apart, rigid, rugged surface sheets and an edge seal defining dead air insulating space there between. 20. The system of claim 12 wherein the pads comprise spaced apart, rigid, rugged surface sheets and an edge seal and a very high insulating value expanded polymer insulating layer there between. 21. The system of claim 20 wherein the expanded polymer is expanded polystyrene. 22. The system of claim 12 wherein the pads are formed by stretching and positioning tight, thin opaques but highly light-reflecting sheets of suitable material over all window areas so as to provide thermal insulating dead-air spaces inside all window areas.

**************

132

133

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close