Vehicle Design
Content
Ashok Leyland AL Standard Design Manual - Vehicle system
ALS.010.01 Issue No : 2 Date : 02.05.1999 Issued to :
Note: This is only for reference. For correctness and validity refer hardcopy standards. Vehicle Design - Design Manual Input Data Application Requirement 1) VEHICLE APLICATION a) Load Carrier : Haulage / Tractor / Tipper / Tanker / Special Application (specify) BUS - City / Intercity / Special application (Specify) b) COUNTRY OF OPERATION. Domestic / Export requirement. c) Operating Requirements Terrains - Highway / Mines / Cross country / Sand / Hill Load / overload / Payload Maintenance practice Chassis weight with FES / cabin / load body 2) DIMENSIONAL REQUIREMENT FOR TRUCKS
Loading span Cubic capacity of tipper Load span for special application (Ex). 118" for iron core carrying tipper 142" for coal carrying tipper Type of cab Overall length of truck Overall width Wheel base FOH ROH Front track Rear track Turning circle diameter Ground clearance Approach angle Departure angle Ramp break over angle FOR BUS No of seat
Seat pitch Saloon space No. of entrances required. Location & width of entrances Tyre and door required / door size Floor height Any other requirement 3) LEGISLATIVE REQUIREMENT (OTHER THAN INDIAN CMVR) 4) SPECIAL REQUIREMENT A/C or heater requirement 5) VEHICLE CONFIGURATION 6X2 / 6X4 / 6X6 / 4X4 / 4X2 / any other 6) COMPETTIION BENCH MARK PERFORMANCE REQUIREMENTS AT RATED LOAD
S. No.
Parameter
Accepted criterion
Standard 1 Max geared speed
Norm Compared with benchmark value of standard model / competition.
2 3
Max powered speed Reserve gradeability in top gear Min 1%
4 5 6
Max gradeability in 1st gear Restart gradeability Acceleration (in secs.) 0 - 40 kmph thro' gears 0 - 50 kmph thro' gears 0 - 60 kmph thro' gears 0 - max. achievable speed.
7
Acceleration (overtaking) in secs 30 - 50 30 - 60
8 9 10
Fuel consumption on highway (kmpl) Life expectancy Clutch disc (in km) 15 years City 60000 Intercity 120000 Mines 30000
11
Cover assy (in km)
City 120000 Intercity 240000 Mines 60000
12
Power to weight ratio.
6 to 8 for MDV (preferred 10) 8 to 12 for LCV min 5. For tractor trailer (preferred 6)
Check vehicle power demand at max. speed with reserve gradeability - as per SAE J688. Choose from the range of engines to give the required power Note RPM and max torque for the above engine. Check the power to weight ratio. Calculate axle load distribution for the wheel base, FOH and ROH selected. Select tyre to match the axle load capacity. Rear axle ratio = (2 II x Rolling radius x N x 60) / (1000 x max speed (kmph) x (GB top gear ratio) for over drive cases. N = engine sped in rpm Rolling radius in meters. Max. gradeability = [(Max engine torque x rear axle ratio x n) / Rolling radius ) - (rolling resistance)] / GVW Overall reduction ratio = GB 1st gear ratio x rear axle ratio Check constant speed fuel consumption for 40, 50, 60 kmph for this new axle for the rated load in top gear. Select clutch size appropriate to the engine and confirm that the clutch heat capacity is adequate as defined in clutch design manual. GEAR BOX SELECTION y y y y y Preferred synchromesh for Truck models. Choose gear box to match engine torque capacity and 1st gear ratio. Number of speeds can be 5 or 6. For passenger vehicle 5 speed gear box and for goods 6 speed gear box preferred. For tippers 5 speed gear box preferred
y
Plot the SAE tooth curve for engine rpm vs vehicle speed. Valley should be close to max torque speed. The connecting valley points should have upward slope. Mass movement of inertia and torsional stiffness of clutch to match the engine and gear box acceptance limit - refer respective design manual.
y
To meet the overall length and wheel base requirement, select the frame from available range (refer frame design manual for detailed selection) Decide centre bearing selection, its mounting and cross member, location of cross member and fastening. Centre bearing cross member should be mounted to match the engine transmission slope.
y
y
PROPELLER SHAFT SELECTION. Select the propeller shaft for wheel base, torque and installation aspects (ref prop. Shaft design manual). After deciding the prop. Shaft length, use rationalised shafts as far as possible and appropriately, select the cross member location and ensure that cross member location is within available span to use the existing frame. Marginally change the prop. Shaft length if required. Install the prop shaft, centre bearing location to meet the resultant angle requirement. If not, accordingly modify centre bearing cross member angular orientation and frame drilling at that location. Select the centre bearing from successful design. Slip joint is required in the last prop shaft in all cases. For the prop shafts with rubber mounted centre bearing, there is no need to have slip joint. If it is self aligning ball bearing, slip joint is required. The normal length selected should cater for the overall slip required for the series of prop shaft verified from layout. In addition for details, refer prop shaft design manual. STEERING SELECITON.
Go as per steering design manual. Mounting arrangement of steering onto the frame depends upon the cab and type of steering used based on customer requirement.' Choice of Mechanical or Power steering is based on steering effort requirement. Accessibility for oil filling and access for steering gear box filler plug should be provided. Reservoir bottom position should be above steering gear box filling level by 100 mm. Reservoir filter elements should be easily removable. Accessibility for Power steering pressure adjustment screw, check the turning circle values to meet the requirement. REAR AXLE. To check rear axle to match axle load, tyre size, wheel size, torque capacity, input flange size. Check ground clearance at bowl. FRONT AXLE. To choose from available range for meeting the axle load for detailed design refer front axle design manual. SUSPENSION. Select the required suspension from the available spring / air suspension. In case the available spring / air suspension does not meet the requirement, design the spring for required load values. Make sure it matches the chassis frame and axle for mounting point. Considering the roll stiffness, decide on the need for antiroll bar. AIR SUSPENSION. y y Calculate air supply requirement and match with the engine compressor. To meet the overall length and wheel base requirement, select the frame from available range (refer frame design manual for detailed selection)
CENTRE BEARING. 1) Rubber mounted centre bearing to be used with fixed type prop shaft without slip joint arrangement. 2) Self aligning type centre bearing to be used with slip joint type prop shaft 3) Greasing provision to be given for the centre bearing. 4) Max. allowable axial movement for rubber mounted centre bearing is s 5 mm. Centre bearing cross member should be mounted to match the engine transmission slope. BRAKE SYSTEM Choice of brake system For MDVs only dual line full air brake to be used. Option for vacuum assisted system for GVW below 6 T. Choice between 'S' cam and wedge brake is dictated by availability, cost comparison, compatibility to application. For passenger bus, 'S' cam brake is preferred. For detailed brake system design, refer brake system design manual. AIR TANK CAPACITY AND PIPING It should meet IS 11852 for charging time, depletion Vs pressure drop. VALVES Unloader valve, system protection valve, air filter, E2 valve, graduated hand control valve, Trailer control valve, PTO operating valve, load sensing valve. LOCATION AND MOUNTING OF VALVE. 1) Unloader valve : Preferred location is nearest to the primary tank.
2) System protection valve : Preferred to mount it through bracket to reduce vibration and liability for setting change. 3) Air filter : Location of filter should be easily accessible for servicing. 4) E2 valve : Choice is between pendent pedal and frame / cab mounted. If it is cab mounted, port accessibility to be ensured. Pedal mounting bracket should be sturdy enough to avoid deflection, brake pedal effort, mounting bolt should have lock nut or spring washer. If panel mounted or floor mounted, sufficient strengthening to be provided in the cab / floor structure. 5) Graduated hand control valve : Location should be accessible for right hand operation of the driver and position marking clearly visible to the driver. GENERAL All special valves mounting should be such that it should be easily accessible for operation and easily serviceable. BRAKE CHAMBER Under articulation, metal to metal minimum clearance between brake chamber and adjoining parts should be maintained. FUEL TANK. y Tank capacity - should be atleast for 500 km for highway running and based on market preference. y y y y y y y y y y y Location on RH side and LH side for LH drive for home market vehicles. Design of fuel tank mounting and bolt selection based on 3g bending load. Ensure the frame long member is stiff enough in the fuel tank mounting region. Filler neck location should not be in the way of body cross bearer. Fuel tank filler neck should be accessible after body building. Filler neck should not project beyond overall width of vehicle. Furl tank cap should not foul with body in fully opening condition. Breather position should be given in cap or filler. Provide sealing for cap and locking provision. Mounting should concide with fuel tank baffles. Fuel tank should meet CMVR requirements for strength, leak and pressure.
y y y
Ensure suction strainer is removable in a body built vehicle. Suction strainer to bottom of tank to be min 10 mm. Suction strainer to be provided at the rear of tank. Provision of drain plug should be in line with suction strainer. It is recommended to have blind hole screw mounting for the tank unit to fuel tank to avoid seepage. Tank unit and gauge to be matched for fuel tank calibration. Provision of return line at fuel tank neck as per current practice. Furl tank should be made of corrosion protection metal. Strap to tank must have insulation. Fuel tank mounting should have enough ground clearance and belly clearance. Water separator if provided should be as close to the fuel tank as possible.
y
y y y y y y
FUEL PIPING y y y y y y Follow same guideline as in air piping Should be away from heat source. Pipe should not project above frame level Effectiveness of clamping to be ensured. Use necessary flexible connection between frame and engine. Provision of rubber grommet if vibration can not be avoided.
SILENCER. y y y y Silencer should meet the engine back pressure, noise and emission standard as per CMVR. Location to meet CMVR. Silencer should be resiliant mounting. Ensure ground clearance. Ensure min clearance between.
Pipe to tyre (directly away from tyre Pipe to shock absorber Pipe to brake hose Pipe to prop shaft Pipe to battery
------
100 mm 100 mm 200 mm 100 mm 200 mm
Pipe to fuel tank Away from wiring harness, fuel pipe, air pipe min Largest unsupported length for the pipe.
----
50 mm 100 mm 2000 mm
At the change of direction of point, support must be given. y Change to silencer pipe length, size, bend radius should confirm validity, engine type approval certification. Whenever, there is a crossing from LH to RH maintain minimum clearance to prop shaft 25 mm from the worst articulated condition. It should not be above frame too. y y Approach departure angle and belly clearance to be ensured. Exhaust tail pipe should be inclined between 10 - 25 r to the horizontal.
AIR TANK AND PIPING. Capacity of tank selection is based on brake requirement and regulation for primary and secondary. It should meet IS 11852 for no of application vs depletion, changing time. In case of auxiliary tank, usage (pneumatic door operation) need for additional capacity to be checked. y y y Tank mounting can be on RH / LH cross member as per frame design / space availability. Check that location of tank does not come in way of door step position in case of bus. Air tank mounting should meet ramp brake over angle, angle of approach and departure and ground clearance requirement. y y y Ensure accessibility for water drain, pipe connections, mounting and ground clearance. Auxiliary tank location should meet requirement of reaction time aspect of regulation. (CMVR) Provision of air dryer, if required, as per regulations or marketing requirements. To be as near the main tank preferable to take support from the chassis. PIPING AND PIPE LAYOUT. Air pipe dia should be adequate to meet regulations in terms of delay / reaction time, charging time, corrosion resistance all the air pipes are to be treated both outside and inside for corrosion resistance. Pipe when laid out thro' long member, ie regions where it crosses outside the long member, there must be a min clearance of 25 mm in the frame to avoid possible fouling with body mounting U bolt. Provide sufficient clamps to avoid rattling.
When bracket mounted, keep the bracket overhang as low to avoid possible rattling. Ensure that the pipe does not touch any cross member, cross member gussets. Provide one flexible hose in the line from compressor to air tank. Where relative motion is possible, chassis mounted, cab mounted or engine mounted, flexible hose to be provided. Hose clip to be provided at accessible area. Hose overlap to pipe min 50 mm. Pipe layout should avoid pinches and kinks and twist in flexible pipe. In metallic pipes, min bend radius to be provided as per current practice. Where this radius can not be met, use an elbow. Parking brake and service brake connection to RH / LH brake chambers to be foot proof. No projections above the frame top level allowed. CONTROLS AND PEDALS.
Accelerator pedal travel
Initial Full pressed condition
-
35 r 17 r .
Provision of idling stop should be provided. Heel support should be provided. Accelerator pedal effort - 6 kg. Clutch pedal effort ICV /MDV - 20 kg. Clutch pedal travel - refer clutch design manual
For clutch, pedal clearance to floor - 25 mm (for floor mounted pedals.) Brake pedal effort - To satisfy the brake performance as per IS 11852 Brake pedal travel - To satisfy the brake performance as per IS 11852 ACCELERATOR LINKAGE. y y y y y y y y Accelerator linkage should meet CMVR regulation. Should not rattle during running and foul with any component thro full travel Provision of lock nut and provision for thread adjustment should be provided with linkage. Whenever ball joint is used, a reserve angle of 5 r should be maintained. Jaw end is used wherever 90 r linkage is used. Link rod strength should have adequate buckling strength under compression. Cable type of accelerator linkage is preferred for 4 cyl. Engine. Lubricated cable to be used.
GENERAL y y y Under rated load, the frame tope should be level There should not be a slope down towards rear under rated load condition. There should be no bowing of the long side members in ROH portion under unladen condition.
CHECK THE FOLLOWING UNDER RATED LOAD CONDITION. y y y Ground clearance. Belly clearance (Ramp break over angle) No part of the vehicle should project with the approach / departure / ramp break over angle areas.
CLERANACE AND ERGONOMIC REQUIREMENTS. Ensure the required clearances as per the validation manual under the vehicle validation procedure (vehicle appraisal) SPARE WHEEL CARRIER LOCATION CHOICE
Side mounted or between long members. If side mounted. a) Mount opposite to drive location b) No hindrance to door location. c) Preferably mount it opposite to fuel tank. d) Reinforce frame side member in mounting location, if necessary. e) Tyre or handle should not project beyond overall width. f) Not to fall within approach angle, departure angle and ramp break over angle. g) Use same size wheel nut for serviceability. If rear mounted. a) Spare wheel carrier should be within angle of departure. b) Should not protrude beyond ROH. AIR INTAKE. y y y To be as per guidelines from engine group to meet pressure drop, intake temp. Air inlet point should be away from water / dust entry zone. Access for service maintenance of air cleaner element hose clips, restriction indicator are to be ensured. y y y Mounting bracket for air cleaner should have adequate strength. In case of tilt cab, the joint or separation point before tilt should provide preloaded sealing. Recommended design values for pressure drop and circuit should be given in the coach builder drawing. y Pipe selection for size and material are to be decided by engine group.
ELECTRICALS. y Battery mounting should not be above top of frame.
y y y
Battery cable length should not exceed 60 r . Alternator location should be away from heat source. When alternator pulley is in max adjusting condition, 25 mm min clearance should be maintained to frame member. Battery cable voltage drop is allowed only upto 0.5 V. Cable 150 mm from heat zone. Adequate clamping to be provided to avoid rubbing against moving parts. Battery cover to be provided to prevent water entry.
y y y y
For special vehicle like Petroleum carrier, check applicable standards. WIRING HARNESS y y y y y Cable size and colour code should be as per electrical design group choice. Connector should be accessible Colour code with identification sleeves at both ends should be provided. Colour coding should conform to SI 13313. Where condur rubbing grommet should be provided. No hanging of wires permitted and should be neatly clamped. y y y y y Headlamp and tail lamp height should meet CMVR requirement. Horn and its mounting should have ground clearance and meet approach angle & water proof. Fuse box and its location should be accessible. Identification of use valves to be visible. Windscreen washer where provided, water filling should be accessible (level should be visible).
GENERAL SERVICEABILITY y y y y y All grease nipple, oil draining points should be accessible. Checking or filling points should be provided by removable lid in the body structure. Engine oil filling / checking to be at one location. Location of dipstick and oil filling preferably from one place. Hose clips must be accessible .
CMVR REQUIREMENT See enclosure.
9. CMV RULES
S. No. 1
Rule No. 93 93(1) 93(2)
Rule Description
Requirement.
OVERALL DIMENSION. a) Overall width b) Overall length (i) Rigid frame with 2 or more axles. (ii) Articulated vehicle. Tractor combination Not more than 11.25 m Not more than 16 m Not more than 18 m Not more than 2.7 m
93(4)
c) Overall height (i) Single decker (ii) Double decker (iii) Trailer with ISO container Not more than 3.8 m Not more than 4.75 m Not more than 4.2 m
93(5) 93(6) 93(7)
Rear overhang of Tractor Rear over hanging other than tractor Lateral projection (i) Beyond centre line of rear axle for single rear wheels. (ii) Beyond outer edge of outer tyre for double rear wheel.
Not more than 1.85 m Not more than 60% WB
Not more than 355 mm
Not more than 152 mm.
95
Size and ply rating of tyres
Max weight not to exceed values specified in CMVR.
2
96
BRAKES Brake performance
IS11852 parts 1 to 7.
3
98 98(1)
STEERING GEARS - Back slash in steering wheel - Protection for call joints Not more than 30 By rubber caps IS 12222 - 1987 IS 11948 - 1986
98(2) 98(3)
- Turning circle diameter - Steering effort.
4
100 100(2)
SAFETY GLASS : Light transmission through front wind screen and rear window Not less than 70%
100(3)
Laminated safety glass for wind screen.
IS 2553 - Part II
5
101 101(2)
WIND SCREEN WIPER. Wiping area and wiping system to confirm to ARAI/005/CMVR/101(2) 12/92 -
6
102
LAMPS Direction indicator - flashes per min colour Colour Illuminated area fir each DL. 60 - 120 Amber 60 cm, min.
Stop lamps : - Numbers and colour - To limit light 2 and red On actuation of services
brakes
7
103 103(1) 103(2)
POSITION OF THE INDICATOR Awareness of operation of D.I indicator to driver. Hazard warning device (flashing of all direction indicators) To be provided. Provision to be made.
8
104 104(1)
FITMENT OF REFLECTORS Reflectors at rear - Numbers and colours - Reflecting area Reflective tape or point of goods vehicle - Width 2 & red 28.5 Front and rear Not less than 20 mm
104(2)
Reflectors at front - Noose and colour - Reflecting area for each 2 and white 28.5 cm IS8339-1992
104(4) 104(5)
All reflector confirm to Reflectors on side (if length exceeds 6 M) - Colours - Height above the ground
Amber Not more than 1500 mm
- Area of reflector - Distance between reflectors
28.5 cm2 Not more than 3 m, with one each to be fitted close to front and rear.
9
105 105(1) 105(2)
LAMPS Front head lamps numbers and colour Rear lamps - number and colour Registration number plate lamp - colour 2 or 4 and white 2 and red White to be visible from 15 m. IS 8415-1977 Clause 4.1 & 4.1.1. 2 and red. Such that to illuminate
105(3)
Height of front head lamps Rear lamps (parking) Numbers and colour
105(5)
Height of rear lamps
registration mark. 105(7) Reverse lamp and audible warning. - Colour of lamp - Operation. White Automatic in reverse gear.
10
106
DEFLECTION OF LIGHTS. Head lamps beam deflection down wards. So as not to dazzle a person standing 8 m from the front & 0.5 m to RH side & 1.5 m front the ground.
11
107
TOP LIGHTS ON GOODS VEHICLE. Front : Number & colour Rear : Number & colour 2 and white 2 and red
12
108
USE OF RED OR WHITE LIGHTS Lights at front Lights at rear No red light No white light except reverse light umber plate light.
13
109
PARKING LIGHTS Front : Numbers & colours Rear : Numbers & colours (can be same as 105(2)) 2 and white 2 and red
14
112
EXHAUST GAS Discharge for non Petroleum vehicles Exhaust tail pipe downwards slope Towards rear on right side. Not more than 30
15
113
LOCATION Distance of exhaust pipes from the fuel lines. Not less than 35 mm
16
115
Engine emissions.
To comply with the norms ref. CMVR rules
17
117
Speedometer : To confirm to
IS 11806-1982
18
118
Speed Governor : To confirm to (type of transport vehicle to be notified by the Central Govt)
IS 10144-1982
19
119
HORNS To confirm to
IS 1884-1992
20 `
120 120(2)
SILENCER Permissible noise limits when tested as per IS 3028 1980 for motor vehicle - Between 4000 to 12000 kg GVW
21
122(1) 122(2)
Chassis and engine number punching Location of punching Height of chassis number
22
124
SAFETY STANDARDS OF COMPONENTS. Ensure availability of Test Reports / Certificates for
To confirm to :
1 2 3 7
Automotive lamps ** Hydraulic brake hoses ** Hydraulic fluid ** Fuel tanks *
IS 1606 - 1979 IS 7079 - 1979 IS 8654 - 4986 IS 12056 - 1987
8
Wheel rims ** Pneumatic compiling **
IS 9436 - 1980 IS 10792 - 1984 SS 2 SS 3 SS 4 SS 9 SS 12 SS 15 SS 29 SS 32 SS 33
10 13 14 15 16 12 17 19 20
Accelerator control systems * Door locks, retention and release ** Wheel nuts, discs and nut caps ** Hood latch systems ** Tell tales and controls * Lighting signalling and indicating device ** External projections * Retention and release of bus windows ** Devices used on motor vehicles **
23
125 125(2) 125(3)
Safety belt for driver and front seat Occupant Rear view mirror Auto dipper
To be provided. To confirm to : To confirm to :
Note :
* indicates self certification. ** indicates suppliers certification.
ALS.010.01 Issue No : 2 Date : 02.05.1999 Issued to :
Note: This is only for reference. For correctness and validity refer hardcopy standards. Vehicle Design - Design Manual Input Data Application Requirement 1) VEHICLE APLICATION a) Load Carrier : Haulage / Tractor / Tipper / Tanker / Special Application (specify) BUS - City / Intercity / Special application (Specify) b) COUNTRY OF OPERATION. Domestic / Export requirement. c) Operating Requirements Terrains - Highway / Mines / Cross country / Sand / Hill Load / overload / Payload Maintenance practice Chassis weight with FES / cabin / load body 2) DIMENSIONAL REQUIREMENT FOR TRUCKS
Loading span Cubic capacity of tipper Load span for special application (Ex). 118" for iron core carrying tipper 142" for coal carrying tipper Type of cab Overall length of truck Overall width Wheel base FOH ROH Front track Rear track Turning circle diameter Ground clearance Approach angle Departure angle Ramp break over angle FOR BUS No of seat
Seat pitch Saloon space No. of entrances required. Location & width of entrances Tyre and door required / door size Floor height Any other requirement 3) LEGISLATIVE REQUIREMENT (OTHER THAN INDIAN CMVR) 4) SPECIAL REQUIREMENT A/C or heater requirement 5) VEHICLE CONFIGURATION 6X2 / 6X4 / 6X6 / 4X4 / 4X2 / any other 6) COMPETTIION BENCH MARK PERFORMANCE REQUIREMENTS AT RATED LOAD
S. No.
Parameter
Accepted criterion
Standard 1 Max geared speed
Norm Compared with benchmark value of standard model / competition.
2 3
Max powered speed Reserve gradeability in top gear Min 1%
4 5 6
Max gradeability in 1st gear Restart gradeability Acceleration (in secs.) 0 - 40 kmph thro' gears 0 - 50 kmph thro' gears 0 - 60 kmph thro' gears 0 - max. achievable speed.
7
Acceleration (overtaking) in secs 30 - 50 30 - 60
8 9 10
Fuel consumption on highway (kmpl) Life expectancy Clutch disc (in km) 15 years City 60000 Intercity 120000 Mines 30000
11
Cover assy (in km)
City 120000 Intercity 240000 Mines 60000
12
Power to weight ratio.
6 to 8 for MDV (preferred 10) 8 to 12 for LCV min 5. For tractor trailer (preferred 6)
Check vehicle power demand at max. speed with reserve gradeability - as per SAE J688. Choose from the range of engines to give the required power Note RPM and max torque for the above engine. Check the power to weight ratio. Calculate axle load distribution for the wheel base, FOH and ROH selected. Select tyre to match the axle load capacity. Rear axle ratio = (2 II x Rolling radius x N x 60) / (1000 x max speed (kmph) x (GB top gear ratio) for over drive cases. N = engine sped in rpm Rolling radius in meters. Max. gradeability = [(Max engine torque x rear axle ratio x n) / Rolling radius ) - (rolling resistance)] / GVW Overall reduction ratio = GB 1st gear ratio x rear axle ratio Check constant speed fuel consumption for 40, 50, 60 kmph for this new axle for the rated load in top gear. Select clutch size appropriate to the engine and confirm that the clutch heat capacity is adequate as defined in clutch design manual. GEAR BOX SELECTION y y y y y Preferred synchromesh for Truck models. Choose gear box to match engine torque capacity and 1st gear ratio. Number of speeds can be 5 or 6. For passenger vehicle 5 speed gear box and for goods 6 speed gear box preferred. For tippers 5 speed gear box preferred
y
Plot the SAE tooth curve for engine rpm vs vehicle speed. Valley should be close to max torque speed. The connecting valley points should have upward slope. Mass movement of inertia and torsional stiffness of clutch to match the engine and gear box acceptance limit - refer respective design manual.
y
To meet the overall length and wheel base requirement, select the frame from available range (refer frame design manual for detailed selection) Decide centre bearing selection, its mounting and cross member, location of cross member and fastening. Centre bearing cross member should be mounted to match the engine transmission slope.
y
y
PROPELLER SHAFT SELECTION. Select the propeller shaft for wheel base, torque and installation aspects (ref prop. Shaft design manual). After deciding the prop. Shaft length, use rationalised shafts as far as possible and appropriately, select the cross member location and ensure that cross member location is within available span to use the existing frame. Marginally change the prop. Shaft length if required. Install the prop shaft, centre bearing location to meet the resultant angle requirement. If not, accordingly modify centre bearing cross member angular orientation and frame drilling at that location. Select the centre bearing from successful design. Slip joint is required in the last prop shaft in all cases. For the prop shafts with rubber mounted centre bearing, there is no need to have slip joint. If it is self aligning ball bearing, slip joint is required. The normal length selected should cater for the overall slip required for the series of prop shaft verified from layout. In addition for details, refer prop shaft design manual. STEERING SELECITON.
Go as per steering design manual. Mounting arrangement of steering onto the frame depends upon the cab and type of steering used based on customer requirement.' Choice of Mechanical or Power steering is based on steering effort requirement. Accessibility for oil filling and access for steering gear box filler plug should be provided. Reservoir bottom position should be above steering gear box filling level by 100 mm. Reservoir filter elements should be easily removable. Accessibility for Power steering pressure adjustment screw, check the turning circle values to meet the requirement. REAR AXLE. To check rear axle to match axle load, tyre size, wheel size, torque capacity, input flange size. Check ground clearance at bowl. FRONT AXLE. To choose from available range for meeting the axle load for detailed design refer front axle design manual. SUSPENSION. Select the required suspension from the available spring / air suspension. In case the available spring / air suspension does not meet the requirement, design the spring for required load values. Make sure it matches the chassis frame and axle for mounting point. Considering the roll stiffness, decide on the need for antiroll bar. AIR SUSPENSION. y y Calculate air supply requirement and match with the engine compressor. To meet the overall length and wheel base requirement, select the frame from available range (refer frame design manual for detailed selection)
CENTRE BEARING. 1) Rubber mounted centre bearing to be used with fixed type prop shaft without slip joint arrangement. 2) Self aligning type centre bearing to be used with slip joint type prop shaft 3) Greasing provision to be given for the centre bearing. 4) Max. allowable axial movement for rubber mounted centre bearing is s 5 mm. Centre bearing cross member should be mounted to match the engine transmission slope. BRAKE SYSTEM Choice of brake system For MDVs only dual line full air brake to be used. Option for vacuum assisted system for GVW below 6 T. Choice between 'S' cam and wedge brake is dictated by availability, cost comparison, compatibility to application. For passenger bus, 'S' cam brake is preferred. For detailed brake system design, refer brake system design manual. AIR TANK CAPACITY AND PIPING It should meet IS 11852 for charging time, depletion Vs pressure drop. VALVES Unloader valve, system protection valve, air filter, E2 valve, graduated hand control valve, Trailer control valve, PTO operating valve, load sensing valve. LOCATION AND MOUNTING OF VALVE. 1) Unloader valve : Preferred location is nearest to the primary tank.
2) System protection valve : Preferred to mount it through bracket to reduce vibration and liability for setting change. 3) Air filter : Location of filter should be easily accessible for servicing. 4) E2 valve : Choice is between pendent pedal and frame / cab mounted. If it is cab mounted, port accessibility to be ensured. Pedal mounting bracket should be sturdy enough to avoid deflection, brake pedal effort, mounting bolt should have lock nut or spring washer. If panel mounted or floor mounted, sufficient strengthening to be provided in the cab / floor structure. 5) Graduated hand control valve : Location should be accessible for right hand operation of the driver and position marking clearly visible to the driver. GENERAL All special valves mounting should be such that it should be easily accessible for operation and easily serviceable. BRAKE CHAMBER Under articulation, metal to metal minimum clearance between brake chamber and adjoining parts should be maintained. FUEL TANK. y Tank capacity - should be atleast for 500 km for highway running and based on market preference. y y y y y y y y y y y Location on RH side and LH side for LH drive for home market vehicles. Design of fuel tank mounting and bolt selection based on 3g bending load. Ensure the frame long member is stiff enough in the fuel tank mounting region. Filler neck location should not be in the way of body cross bearer. Fuel tank filler neck should be accessible after body building. Filler neck should not project beyond overall width of vehicle. Furl tank cap should not foul with body in fully opening condition. Breather position should be given in cap or filler. Provide sealing for cap and locking provision. Mounting should concide with fuel tank baffles. Fuel tank should meet CMVR requirements for strength, leak and pressure.
y y y
Ensure suction strainer is removable in a body built vehicle. Suction strainer to bottom of tank to be min 10 mm. Suction strainer to be provided at the rear of tank. Provision of drain plug should be in line with suction strainer. It is recommended to have blind hole screw mounting for the tank unit to fuel tank to avoid seepage. Tank unit and gauge to be matched for fuel tank calibration. Provision of return line at fuel tank neck as per current practice. Furl tank should be made of corrosion protection metal. Strap to tank must have insulation. Fuel tank mounting should have enough ground clearance and belly clearance. Water separator if provided should be as close to the fuel tank as possible.
y
y y y y y y
FUEL PIPING y y y y y y Follow same guideline as in air piping Should be away from heat source. Pipe should not project above frame level Effectiveness of clamping to be ensured. Use necessary flexible connection between frame and engine. Provision of rubber grommet if vibration can not be avoided.
SILENCER. y y y y Silencer should meet the engine back pressure, noise and emission standard as per CMVR. Location to meet CMVR. Silencer should be resiliant mounting. Ensure ground clearance. Ensure min clearance between.
Pipe to tyre (directly away from tyre Pipe to shock absorber Pipe to brake hose Pipe to prop shaft Pipe to battery
------
100 mm 100 mm 200 mm 100 mm 200 mm
Pipe to fuel tank Away from wiring harness, fuel pipe, air pipe min Largest unsupported length for the pipe.
----
50 mm 100 mm 2000 mm
At the change of direction of point, support must be given. y Change to silencer pipe length, size, bend radius should confirm validity, engine type approval certification. Whenever, there is a crossing from LH to RH maintain minimum clearance to prop shaft 25 mm from the worst articulated condition. It should not be above frame too. y y Approach departure angle and belly clearance to be ensured. Exhaust tail pipe should be inclined between 10 - 25 r to the horizontal.
AIR TANK AND PIPING. Capacity of tank selection is based on brake requirement and regulation for primary and secondary. It should meet IS 11852 for no of application vs depletion, changing time. In case of auxiliary tank, usage (pneumatic door operation) need for additional capacity to be checked. y y y Tank mounting can be on RH / LH cross member as per frame design / space availability. Check that location of tank does not come in way of door step position in case of bus. Air tank mounting should meet ramp brake over angle, angle of approach and departure and ground clearance requirement. y y y Ensure accessibility for water drain, pipe connections, mounting and ground clearance. Auxiliary tank location should meet requirement of reaction time aspect of regulation. (CMVR) Provision of air dryer, if required, as per regulations or marketing requirements. To be as near the main tank preferable to take support from the chassis. PIPING AND PIPE LAYOUT. Air pipe dia should be adequate to meet regulations in terms of delay / reaction time, charging time, corrosion resistance all the air pipes are to be treated both outside and inside for corrosion resistance. Pipe when laid out thro' long member, ie regions where it crosses outside the long member, there must be a min clearance of 25 mm in the frame to avoid possible fouling with body mounting U bolt. Provide sufficient clamps to avoid rattling.
When bracket mounted, keep the bracket overhang as low to avoid possible rattling. Ensure that the pipe does not touch any cross member, cross member gussets. Provide one flexible hose in the line from compressor to air tank. Where relative motion is possible, chassis mounted, cab mounted or engine mounted, flexible hose to be provided. Hose clip to be provided at accessible area. Hose overlap to pipe min 50 mm. Pipe layout should avoid pinches and kinks and twist in flexible pipe. In metallic pipes, min bend radius to be provided as per current practice. Where this radius can not be met, use an elbow. Parking brake and service brake connection to RH / LH brake chambers to be foot proof. No projections above the frame top level allowed. CONTROLS AND PEDALS.
Accelerator pedal travel
Initial Full pressed condition
-
35 r 17 r .
Provision of idling stop should be provided. Heel support should be provided. Accelerator pedal effort - 6 kg. Clutch pedal effort ICV /MDV - 20 kg. Clutch pedal travel - refer clutch design manual
For clutch, pedal clearance to floor - 25 mm (for floor mounted pedals.) Brake pedal effort - To satisfy the brake performance as per IS 11852 Brake pedal travel - To satisfy the brake performance as per IS 11852 ACCELERATOR LINKAGE. y y y y y y y y Accelerator linkage should meet CMVR regulation. Should not rattle during running and foul with any component thro full travel Provision of lock nut and provision for thread adjustment should be provided with linkage. Whenever ball joint is used, a reserve angle of 5 r should be maintained. Jaw end is used wherever 90 r linkage is used. Link rod strength should have adequate buckling strength under compression. Cable type of accelerator linkage is preferred for 4 cyl. Engine. Lubricated cable to be used.
GENERAL y y y Under rated load, the frame tope should be level There should not be a slope down towards rear under rated load condition. There should be no bowing of the long side members in ROH portion under unladen condition.
CHECK THE FOLLOWING UNDER RATED LOAD CONDITION. y y y Ground clearance. Belly clearance (Ramp break over angle) No part of the vehicle should project with the approach / departure / ramp break over angle areas.
CLERANACE AND ERGONOMIC REQUIREMENTS. Ensure the required clearances as per the validation manual under the vehicle validation procedure (vehicle appraisal) SPARE WHEEL CARRIER LOCATION CHOICE
Side mounted or between long members. If side mounted. a) Mount opposite to drive location b) No hindrance to door location. c) Preferably mount it opposite to fuel tank. d) Reinforce frame side member in mounting location, if necessary. e) Tyre or handle should not project beyond overall width. f) Not to fall within approach angle, departure angle and ramp break over angle. g) Use same size wheel nut for serviceability. If rear mounted. a) Spare wheel carrier should be within angle of departure. b) Should not protrude beyond ROH. AIR INTAKE. y y y To be as per guidelines from engine group to meet pressure drop, intake temp. Air inlet point should be away from water / dust entry zone. Access for service maintenance of air cleaner element hose clips, restriction indicator are to be ensured. y y y Mounting bracket for air cleaner should have adequate strength. In case of tilt cab, the joint or separation point before tilt should provide preloaded sealing. Recommended design values for pressure drop and circuit should be given in the coach builder drawing. y Pipe selection for size and material are to be decided by engine group.
ELECTRICALS. y Battery mounting should not be above top of frame.
y y y
Battery cable length should not exceed 60 r . Alternator location should be away from heat source. When alternator pulley is in max adjusting condition, 25 mm min clearance should be maintained to frame member. Battery cable voltage drop is allowed only upto 0.5 V. Cable 150 mm from heat zone. Adequate clamping to be provided to avoid rubbing against moving parts. Battery cover to be provided to prevent water entry.
y y y y
For special vehicle like Petroleum carrier, check applicable standards. WIRING HARNESS y y y y y Cable size and colour code should be as per electrical design group choice. Connector should be accessible Colour code with identification sleeves at both ends should be provided. Colour coding should conform to SI 13313. Where condur rubbing grommet should be provided. No hanging of wires permitted and should be neatly clamped. y y y y y Headlamp and tail lamp height should meet CMVR requirement. Horn and its mounting should have ground clearance and meet approach angle & water proof. Fuse box and its location should be accessible. Identification of use valves to be visible. Windscreen washer where provided, water filling should be accessible (level should be visible).
GENERAL SERVICEABILITY y y y y y All grease nipple, oil draining points should be accessible. Checking or filling points should be provided by removable lid in the body structure. Engine oil filling / checking to be at one location. Location of dipstick and oil filling preferably from one place. Hose clips must be accessible .
CMVR REQUIREMENT See enclosure.
9. CMV RULES
S. No. 1
Rule No. 93 93(1) 93(2)
Rule Description
Requirement.
OVERALL DIMENSION. a) Overall width b) Overall length (i) Rigid frame with 2 or more axles. (ii) Articulated vehicle. Tractor combination Not more than 11.25 m Not more than 16 m Not more than 18 m Not more than 2.7 m
93(4)
c) Overall height (i) Single decker (ii) Double decker (iii) Trailer with ISO container Not more than 3.8 m Not more than 4.75 m Not more than 4.2 m
93(5) 93(6) 93(7)
Rear overhang of Tractor Rear over hanging other than tractor Lateral projection (i) Beyond centre line of rear axle for single rear wheels. (ii) Beyond outer edge of outer tyre for double rear wheel.
Not more than 1.85 m Not more than 60% WB
Not more than 355 mm
Not more than 152 mm.
95
Size and ply rating of tyres
Max weight not to exceed values specified in CMVR.
2
96
BRAKES Brake performance
IS11852 parts 1 to 7.
3
98 98(1)
STEERING GEARS - Back slash in steering wheel - Protection for call joints Not more than 30 By rubber caps IS 12222 - 1987 IS 11948 - 1986
98(2) 98(3)
- Turning circle diameter - Steering effort.
4
100 100(2)
SAFETY GLASS : Light transmission through front wind screen and rear window Not less than 70%
100(3)
Laminated safety glass for wind screen.
IS 2553 - Part II
5
101 101(2)
WIND SCREEN WIPER. Wiping area and wiping system to confirm to ARAI/005/CMVR/101(2) 12/92 -
6
102
LAMPS Direction indicator - flashes per min colour Colour Illuminated area fir each DL. 60 - 120 Amber 60 cm, min.
Stop lamps : - Numbers and colour - To limit light 2 and red On actuation of services
brakes
7
103 103(1) 103(2)
POSITION OF THE INDICATOR Awareness of operation of D.I indicator to driver. Hazard warning device (flashing of all direction indicators) To be provided. Provision to be made.
8
104 104(1)
FITMENT OF REFLECTORS Reflectors at rear - Numbers and colours - Reflecting area Reflective tape or point of goods vehicle - Width 2 & red 28.5 Front and rear Not less than 20 mm
104(2)
Reflectors at front - Noose and colour - Reflecting area for each 2 and white 28.5 cm IS8339-1992
104(4) 104(5)
All reflector confirm to Reflectors on side (if length exceeds 6 M) - Colours - Height above the ground
Amber Not more than 1500 mm
- Area of reflector - Distance between reflectors
28.5 cm2 Not more than 3 m, with one each to be fitted close to front and rear.
9
105 105(1) 105(2)
LAMPS Front head lamps numbers and colour Rear lamps - number and colour Registration number plate lamp - colour 2 or 4 and white 2 and red White to be visible from 15 m. IS 8415-1977 Clause 4.1 & 4.1.1. 2 and red. Such that to illuminate
105(3)
Height of front head lamps Rear lamps (parking) Numbers and colour
105(5)
Height of rear lamps
registration mark. 105(7) Reverse lamp and audible warning. - Colour of lamp - Operation. White Automatic in reverse gear.
10
106
DEFLECTION OF LIGHTS. Head lamps beam deflection down wards. So as not to dazzle a person standing 8 m from the front & 0.5 m to RH side & 1.5 m front the ground.
11
107
TOP LIGHTS ON GOODS VEHICLE. Front : Number & colour Rear : Number & colour 2 and white 2 and red
12
108
USE OF RED OR WHITE LIGHTS Lights at front Lights at rear No red light No white light except reverse light umber plate light.
13
109
PARKING LIGHTS Front : Numbers & colours Rear : Numbers & colours (can be same as 105(2)) 2 and white 2 and red
14
112
EXHAUST GAS Discharge for non Petroleum vehicles Exhaust tail pipe downwards slope Towards rear on right side. Not more than 30
15
113
LOCATION Distance of exhaust pipes from the fuel lines. Not less than 35 mm
16
115
Engine emissions.
To comply with the norms ref. CMVR rules
17
117
Speedometer : To confirm to
IS 11806-1982
18
118
Speed Governor : To confirm to (type of transport vehicle to be notified by the Central Govt)
IS 10144-1982
19
119
HORNS To confirm to
IS 1884-1992
20 `
120 120(2)
SILENCER Permissible noise limits when tested as per IS 3028 1980 for motor vehicle - Between 4000 to 12000 kg GVW
21
122(1) 122(2)
Chassis and engine number punching Location of punching Height of chassis number
22
124
SAFETY STANDARDS OF COMPONENTS. Ensure availability of Test Reports / Certificates for
To confirm to :
1 2 3 7
Automotive lamps ** Hydraulic brake hoses ** Hydraulic fluid ** Fuel tanks *
IS 1606 - 1979 IS 7079 - 1979 IS 8654 - 4986 IS 12056 - 1987
8
Wheel rims ** Pneumatic compiling **
IS 9436 - 1980 IS 10792 - 1984 SS 2 SS 3 SS 4 SS 9 SS 12 SS 15 SS 29 SS 32 SS 33
10 13 14 15 16 12 17 19 20
Accelerator control systems * Door locks, retention and release ** Wheel nuts, discs and nut caps ** Hood latch systems ** Tell tales and controls * Lighting signalling and indicating device ** External projections * Retention and release of bus windows ** Devices used on motor vehicles **
23
125 125(2) 125(3)
Safety belt for driver and front seat Occupant Rear view mirror Auto dipper
To be provided. To confirm to : To confirm to :
Note :
* indicates self certification. ** indicates suppliers certification.
