3. • UNIT I VEHICLE STRUCTURE AND ENGINES
Types of automobiles, vehicle construction
and different layouts, chassis, frame and body,
Vehicle aerodynamics(various resistances and
moments involved), IC engines –components
functions and materials, variable valve timing
(VVT).
5. TYPES OF AUTOMOBILES
• (i) with respect to the purpose
• (a) Passenger vehicles. Ex. Car, bus, jeep, scooter, mopeds and motor
cycles
• (b) Goods carriers: ex. Trucks and lorries
• (ii) weight of the vehicles:
• - Heavy weight vehicle- buses, trucks and trailers
• - Light weight vehicles - cars, jeeps
• - Medium weigh vehicles – minibus and station wagon
• (iii) With respect to the fuel:
• - Petrol vehicles – scooters, cars motors cycles
• - Diesel vehicles - Buses , trucks
• Gas vehicles – Coal gas, LPG, CNG vehicles
• Electric vehicle – Heavy cranes, battery truck, cars and fork lifts
• Solar vehicles.
6. • (iv) with respect to capacity:
• Heavy transport vehicles – Bus lorries, trucks, tractors
• Light transport vehicles _ Car, scooter, mopeds, motor
cycles, jeeps
• (v) with respect to number of wheels:
• Two wheelers – Scooters, mopeds
• Four wheelers – car, jeep, buses, truckes
• Three wheelers – Auto, tempos
• Six wheelers - heavy trucks
• (vi) With respect to side of driver seat
• - Left hand drive- American, European and UAE
• -Right hand drive – Indian vehicles
7. • Bullock cart consists of
• (i) Frame (ii) wheels & axle
• (iii) Yoke (iv) Body or superstructure and
platform
• These pars can be divided into two main
portions
• (i) Machine portion (ii)carriage portion
11. Classification of chassis
• According to the fitting of engine
1.Full-forward – Cars, mahindra jeeps
2.Semi-forward – Tata series of vehicle
3. Bus chassis
4. Engine at back -volkswagen cars, layland bus of
england.
5. Engine at centre.-royal tiger world master buses of
Delhi transport.
• According to the number of wheels fitted in the wheels
1.4x2 drive chassis 2. 4x4 drive chassis
3. 6x2 drive chassis 4. 6x4 drive chassis
14. Characteristics of Good Chassis
• Fast pickup
• Strength
• Safety
• Durability
• Ease of control
• Speed
• Power accessibility
• Economy of operation
• Low centre of gravity
• Stability
• Load clearance
• Braking ability
• Simplicity of lubrication
15. FRAME
• Main part of the chassis
• Backbone of the vehicle.
Functions of the frame
• To form the base for mounting engine & transmission
systems
• To withstand the engine & transmission thrust & torque
stresses as well as accelerating and braking torque
• To accommodate suspension system
• To carry the other parts of the vehicle & its passengers
• To resist the effect of centrifugal forces when cornering
a curve
• To with stand bending and twisting stresses
21. RESISTANCES TO VEHICLE MOTION
1. Air resistance:
a. Size of vehicle b. Shape
c. Speed d. Wind velocity
2.Gradient resistances:
The component of the vehicle’s weight which is
parallel to the plane of the road. This component
remains constant but independent of the vehicle
speed.
3. Miscellaneous resistance:
a. Road characteristics b. Tyre characteristics
c. Vehicle weight d. Vehicle speed
28. PISTON RINGS
Cast iron, alloy cast iron containing silicon and manganese, alloy
steels etc.
•piston rings are generally coated with chromium or cadmium.
29. CRANK SHAFT
carbon steel, nickel-chromium and other heat treated alloy
steels.