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Post on 12-Sep-2014
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Introduction to Automobile
Components of an Automobile• The basic structure
• The power unit
• The transmission system
• The auxiliaries
• The controls
• The superstructure
The Basic Structure (Chassis)• This is the unit on which the other units are
mounted.
• It consists of:-– Frame– The Suspension system– Axles– Wheels – Tyres
1. Frame• There consists of two distinct forms
construction in common use:
1. The conventional pressed steel frame to which all units are mounted
2. The integral or frameless construction, in which the body structure is so designed so as to combine the functions of body and frame.
Frameless - Advantages• Reduced weight and consequent saving in fuel
consumption
• Lower manufacturing costs
• Safety to passengers
• Increased stability of the automobile
Disadvantages • Reduction in strength and durability
• Economical only if it is adopted in mass production
• Increased cost or repairs
• Convertible cars are difficult to design in frameless construction
2. Suspension System• The objects of the suspension are:– To prevent the road shocks from being
transmitted to the vehicle components
– To safeguard the occupants from road shocks
– To preserve the stability of the vehicle while in motion
Leaf Springs
Suspension system
Suspension system• There are two distinct types of suspension
systems:– The conventional system, in which the road
springs are attached to a rigid beam axle.
– The independent system, in which there is no rigid axle beam and each wheel is free to move vertically
Suspension system
3. Axles• It is the wait carrying members, may be on the
rear or front, are beams supported at ends.
• Axles are subjects to different kin of loads:– Vertical load due to self weight– A fore and aft load due to driving and braking– Torque reactions due to drive and brake– Side thrust due to centrifugal force during conference
Axles• There are three different types live rear axles
a) Fully floating type
b) Three quarter floating type
c) Semi-floating type
4. Wheels • Different types of wheels have been used in
automobiles over generations according to the requirement
Wire-spoked wheels
Pressed steel wheels
Light alloy wheels
The Power Plant (Engine)• The engine provides the power to move the
vehicle
• It generally consists of an IC engine, either SI or CI
• Gas turbines also have been used in vehicles
• Now, electric batteries for propelling the vehicle
The Transmission System• The transmission system consists of a– Clutch,
– Gear box,
– Propeller shaft, and
– Differential
Layout of the transmission system
The Transmission System• The functions of a transmission system are:– To disconnect the engine from road wheel when
desired
– To connect the engine to the driving wheels without shock
– To vary the leverage between the engine and the driving wheels
The Transmission System
– To reduce the engine speed permanently in a fixed ratio
– To turn the drive through a right angle
– To make provision for the flexing of the road springs
The Transmission System• The various components which perform the
above mentioned functions are:– Clutch:- To disengage the system from the engine
and to engage without shock to road wheels
– Gear box:- Provides the necessary leverage variation between the engine and road wheels
The Transmission System– Bevel pinion and crown wheels:- They turn the drive
round through 90° and also provide permanent reduction in speed
– Universal joints:- Provide for the relative movement between the engine and the driving wheels due to flexing of road springs.
– Differential:- Helps to attain different speeds at different wheels while taking a turn
The different types of the arrangement of transmission could be
• Front engine and front wheel drive
• Rear engine and rear wheel drive
• Front engine and four wheel drive
Different types of arrangements
Front engine FWD• The power is transmitted to front axles, from
the front engine (Front Wheel Drive)• A few advantages are:
i. The propeller shaft is eliminated. This permits low chassis height
ii. The pulls the car than pushing it, avoiding skidding tendency.
iii. Better road adhesion.
FWD
Layout of FWD
FWD• A few disadvantages are:
i. The whole arrangement over front wheels is complicated.
ii. Constant velocity joints have to be used instead of universal joints
iii. Decrease of tractive forces when the vehicle is up the grade.
Rear engine RWD• The engine is placed at the rear and the rear
wheels are the driven wheels• Advantages are:
i. Better tractive forces up the gradeii. Front axle construction is simplifiediii. Absence of propeller shaft allows decrease in
chassis height
RWD• The disadvantages are:
i. May lose balance at high speeds.
ii. Complicated linkage is required between the engine, clutch and gearbox.
iii. Rear position of engine, cooling effect is reduced.
Front engine four wheel drive• Vehicles which operate on rough roads and
unexpected road profiles, all the four wheels are the driving wheels
• It has got an extra transfer box, which divides the torque between front and rear wheels.
• Also there is a provision for disengaging the front wheels when not required.
4WD
4WD
Transfer Box in 4WD
4WD• The main advantage of the 4WD is that when
any wheels fall into a ditch or a hole, they can be driven out with the help of other wheels or power being delivered to the same wheel
• But this advantage can only at the cost of extra fuel consumption.
Classification
Automobiles can be classified in different in ways according to:-
1.Use i. Mopedsii. Motor cycles, scootersiii. Cars, jeepsiv. Buses and trucks
Classifications2. Capacity
i. Heavy transportii. Light weight transport
3. Make and modeli. Honda, Bajaj, TVS, etc.ii. Maruti Suzuki, Tata, Mahindra etc.iii. BMW, Audi, Ford, Mitsubishi etc.
Classifications4. Fuel Used
i. Petrol vehiclesii. Diesel vehicles
5. Body stylei. Closed cars e.g., sedan, coupe etc.ii. Open cars e.g., convertibleiii. Special styles e.g., estate cars, station wagons etc.
Classifications6. Transmission
i. Manual
ii. Semi-automatic
iii. Fully-automatic
iv. Continuously variable transmission
v. Automated manual
Car Body Styles
I. Closed cars:a. Sedan – has two or four doors, single
compartment with two rows of seats.
b. Hatchback – A sedan with a door at the back
c. Coupe – only one row of seats for two persons. Only two doors are provided.
Different Closed Cars
Honda Sedan
Different Closed Cars
Suzuki SX4
Different Closed Cars
Ford Fiesta 5 door hatchback
Different Closed Cars
Honda Civic Hatchback
Different Closed Cars
Honda Genesis Coupe
Different Closed Cars
Honda Accord Coupe
Different Closed Cars
BMW X Coupe
Car Body Styles
II. Open carsa) Sports – Has two doors or less, provided with a
collapsible hood, a fold-flat windscreen and removable side-screen.
b) Convertible – Roof in this is of folding type. So the car roof can be closed or opened.
Different Open Cars
Peugeot 9009 Sports Car
Different Open Cars
Dodge Viper Sports Car
Different Open Cars
Audi Sports Car
Different Open Cars
Ford Mustang Convertible
Different Open Cars
BMW M3 Convertible
Different Open Cars
BMW M6 Convertible
Different Open Cars
Chevrolet Camaro Convertible
Car Body Styles
III. Special stylesa) Estate car – A sedan with the passenger roof
extended up to rear end. Rear seats are usually collapsible for loading.
b) Station wagon – Rear doors and four or five person seating capacity.
Special Style Cars
Mercedes AMG Estate
Audi RS 6 Estate Car
Special Style Cars
Special Style Cars
Renault Clio Estate
Ford Mustang Station Wagon
Special Style Cars
Special Style Cars
Station Wagon
Special Style Cars
Station Wagon
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