The number of textbooks available on ‘Automobile Engineering’ is not very large. The field and scope of automobile engineering is enormous. Every manufacturer of automobile has his own resources and is trying to improve the product in his own manner. Number of automobile manufacturers being very large, the development in this field is very quick. The present book attempts to explain different aspects of automobile engineering in a simple way. The diagrams that have been included in the text are simple and can be followed easily. Every attempt has been made to include the latest development in this field. It is hoped that the book would prove useful to the undergraduate/post graduate engineering students particularly those studying mechanical engineering. It is very much possible that some mistakes have been left in the text of the book though every effort has been made to remove them. Author would feel oblige if the mistakes are brought to notice. Author would also welcome the comments and suggestions by experts in this field, particularly those in the industrial organisations, to improve the book in forthcoming editions.
Additional Info
  • Publisher: Laxmi Publications
  • Language: English
  • Chapter 1

    INTRODUCTION Price 2.99  |  2.99 Rewards Points

    a. .u'to mo bile' " −− −− (or a to mo' bil . .− −− − ), n. [auto-, and L. mobils, movable.] a car, usually four-wheeled, propelled by an engine or motor that is a part of it, and meant for travelling on streets or roads; a motor car.
  • Chapter 2

    INTERNAL COMBUSTION ENGINES Price 2.99  |  2.99 Rewards Points

    An internal combustion engine is the source of ‘power’ in an automobile. Internal combustion engines can be broadly classified on the basis of their working, number of cylinders and fuel used. On the basis of their working the engine can be two stroke or four stroke. In two stroke engines the working cycle is completed in one revolution (360°) of crankshaft. In four stroke engine the working cycle is completed in two revolutions (720°) of crankshaft. In automobiles four stroke engines are used. As far as the classification of the basis of number of cylinders is concerned the engines can be single cylinder or multicylinder. A multi-cylinder engine is more suitable for automobiles. Conventionally the engines used petrol or diesel as fuel and accordingly these are classified as petrol engine or diesel engine. Lately, some alternate fuels such as compressed natural gas, hydrogen etc. have also been used. Few hybrid cars with twin engines are also being developed. These cars are equipped with electric motor running with battery alongwith conventional engine.
  • Chapter 3

    FUEL INJECTION SYSTEMS Price 2.99  |  2.99 Rewards Points

    Fuel injection has been utilised in compression ignition engines since beginning but has been introduced in spark ignition engine lately. These are developed for more efficient use of fuel. To make them more dependable electronic control systems were introduced in the eighties. Fuel injection system supplies the engine with a combustible air-fuel mixture. The richness of the mixture varies depending upon various operating conditions. When cold started, the engine needs very rich mixture with higher fuel contents. Afterwards, as engine warms up lean mixture with less fuel is sufficient. During acceleration and at high speeds again the increased quantity of fuel is needed.
  • Chapter 4

    MULTICYLINDER INTERNAL COMBUSTION ENGINES Price 2.99  |  2.99 Rewards Points

    Internal combustion engines are the source of power in an automobile. Automobiles became more usable with introduction of internal combustion engine. An automobile requires good amount of power to move efficiently. There are certain problems in employing a single cylinder engine. One of these being that a single cylinder engine will become too heavy. It will also have problem of mechanical balance. Therefore, multicylinder engines are better option.
  • Chapter 5

    PERFORMANCE OF INTERNAL COMBUSTION ENGINES Price 2.99  |  2.99 Rewards Points

    Internal Combustion engine is the source of power in an automobile. The performance of automobile is dependent upon the performance of its other components to a large extent. It depends upon the performance of engine. The performance of engine is measured on the basis of input which is given to engine and output that is obtained from the engine. The input to engine is in the form of fuel which is due to its properties containing chemical energy. The combustion of fuel, which is a form of chemical reaction, causes the conversion of chemical energy into thermal energy. As a product of combustion, hot gases are obtained at high pressure which force the piston to move downwards. Thus the thermal energy is converted into work. This motion is transferred to crankshaft and can be considered output of the engine.
  • Chapter 6

    COOLING AND LUBRICATION Price 2.99  |  2.99 Rewards Points

    Upon combustion, the chemical energy contained in the fuel is converted into thermal energy. Thermal energy in the form of hot gases exerting pressure on piston causes its movement. This way the thermal energy is converted into mechanical energy. The conversion from thermal to mechanical energy is not efficient. Only a part of thermal energy is converted into mechanical energy. The unused thermal energy causes a rise in temperature. At high temperature the viscosity of the lubricant is reduced. The change in viscosity deforms the lubricant layer and there may be direct contact between metal parts causing damage to them. The remaining excessive thermal energy is transferred to the adjoining engine parts such as piston, liner, cylinder and cylinder head. The heat may get accumulated in these parts causing a continuous rise in the temperature of these parts. This may cause deformation of the parts such as piston and liner. Due to this, the piston may seize and engine may stop working. The high temperature also causes excessive stress in parts reducing their life. Some heat may be carried away by lubricating oil and some may get lost to the surroundings through radiation. But heat taken by lubricating oil and that lost to surroundings is only about 12% of total heat supplied. A part of heat is taken away by exhaust gases. This may be about 30% in case of four stroke engine. Useful conversion into mechanical energy is about 28%. Hence about 30% of unused heat remains inside the engine. To avoid accumulation of this heat in the different parts it becomes essential to dissipate it efficiently and continuously. To achieve this, an engine cooling system is employed.
  • Chapter 7

    ENGINE FUELS Price 2.99  |  2.99 Rewards Points

    The energy input in an internal combustion engine is the chemical energy possessed in the fuel. This is naturally provided in the fuel. Combustibility is another property naturally provided to fuels. Combustion of fuel causes conversion of chemical energy into thermal energy. Thermal energy is available which is further converted into mechanical energy that is the output from the internal combustion engine. Almost all of the fuels for internal combustion engine are derived from petroleum, which is a complex combination of hydro carbon compounds. Petroleum is available from beneath the surface of the earth and is a product of process that has undergone beneath the surface of the earth for several hundred years. Unfortunately, it is not available uniformly throughout the earth. It is accumulated in some parts of the earth and some parts are totally deprived of it. Another important thing is that the quantity of fuel available from beneath the surface of the earth is limited.
  • Chapter 8

    TRANSMISSION SYSTEM Price 2.99  |  2.99 Rewards Points

    The internal combustion engine generates power which is transmitted to the road wheels. The output from engine is available in the form of rotation of crankshaft. This rotary motion is transmitted to the road wheels. The friction between road and the surface of the wheel makes possible the movement of automobile. Transmission system performs this function. The transmission system consists of a number of components. These components work together to transmit the rotary motion at the crankshaft smoothly and efficiently to the road wheels.
  • Chapter 9

    THE CLUTCH Price 2.99  |  2.99 Rewards Points

    The clutch enables the rotary motion of crankshaft to be transmitted to driven shaft when desired and gradually. These can be classified as: 1. Positive Clutch 2. Gradual Engagement Clutch 1. Positive Clutch: In this type of clutch there are two positions. Either it is ‘in’ when the two shafts are rigidly connected and revolve at the same speed or it is ‘out’ when the shafts are entirely disconnected and there is no transfer of motion and the driven shaft is not moving. This type of clutch is not suitable for use between the engine and the gear box as the motion will be suddenly transferred. Also the transfer of motion will suddenly stop. This means sudden movement of vehicle from rest and sudden stoppage of the movement. Both the situations are not desirable as sudden change of state from rest to motion or vice versa will be highly uncomfortable or even injurious to the user of the vehicle. 2. Gradual Engagement Clutch: In this type of clutch it is possible that driving shaft is rotating and the other shaft, driven shaft, is stationary. As the engagement of clutch proceeds the speed of the two shafts gradually becomes almost equal. When the clutch is fully engaged both the shafts rotate almost at the same speed. This type of clutch is used between the engine and the gear box. In this type of clutch the transfer of motion between the two shafts depends upon the friction between the surfaces of the two shafts when these come in contact with each other. Therefore, these are also known as friction clutch.
  • Chapter 10

    GEAR BOX Price 2.99  |  2.99 Rewards Points

    Gear box provides the required leverage between the engine and the road wheels. The output from the engine can be considered almost constant but the resistance to motion experienced by a vehicle may be different in different situations. A vehicle may be moving on a level road and moving upwards on hilly road, in both cases the resistance experienced by it will be different and vehicle should be capable of overcoming resistance in both the situations. When a vehicle is moving at a uniform speed, there are various forces opposing its motion. In order to keep it moving, a driving force or tractive effort equal to the sum of all the opposing forces has to be provided to it. If this tractive effort is more than the sum of resistive forces the vehicle will accelerate and if its less the vehicle will deaccelerate. The forces opposing the motion can be divided as:
  • Chapter 11

    PROPELLER SHAFT, DIFFERENTIAL AND AXLE Price 2.99  |  2.99 Rewards Points

    The motion from gear box is transferred to differential which is the next component of the transmission system. The differential is located in the middle of the rear axle and the vehicle is rear wheel drive. Alternatively, the vehicle may be front wheel drive or in some cases, motion from the engine may be transferred to both-front and rear axles. In case of rear wheel drive vehicle the distance between the gear box and differential may be considerable and the propeller shaft connecting the two has considerable length. In case of front wheel drive the distance between the two may be small and so small propeller shaft would be required. To study the propeller shaft, it is proper to consider vehicle with rear wheel drive.
  • Chapter 12

    WHEELS Price 2.99  |  2.99 Rewards Points

    Wheels, together with tyres and tubes, form a single unit to provide motion to an automobile. These support the automobile on road and take up its load. Generally there are four wheels but often to enhance the load carrying capacity the number of wheels may be more than four. Tyres and tubes are made of soft rubber. The tubes are inflated and provide flexible support to the automobile.
  • Chapter 13

    BRAKES Price 2.99  |  2.99 Rewards Points

    The primary function of an automobile is to move from one place to another. As the automobile moves from one place to another, it is very important to keep control on its movement. The driver must have complete control on the movement. He/she should be able to reduce its speed whenever needed and also the automobile must stop when desired. Brakes are the control mechanism in an automobile. These are used to control the movement of the automobile. These provide frictional resistance to the motion of the wheel thus causing reduction in the speed or stopping of the automobile. Due to frictional resistance, the kinetic energy of the wheel is converted into heat which is dissipated to the atmosphere suitably.
  • Chapter 14

    ANTILOCK BRAKE SYSTEM Price 2.99  |  2.99 Rewards Points

    Brakes are an essential controlling device in modern day’s automobiles. Automobiles today can run at very high speed and controlling motion at high speed, particularly when brakes are applied, could cause instability. At high speed when brakes are applied, the wheels become stationary and these start sliding instead of rolling on the road surface. As the wheel starts sliding, the steering control is also lost and the vehicle cannot be kept straight. The force of friction is reduced and that also causes instability. It becomes difficult for the driver to keep the vehicle straight and the vehicle skids and goes out of control. This situation is dangerous and an accident can occur. It becomes essential to keep the vehicle under control when brakes are applied. This is achieved by antilock brake system (ABS).
  • Chapter 15

    STEERING SYSTEM Price 2.99  |  2.99 Rewards Points

    Steering system in an automobile controls the direction of motion. It also changes the direction of motion. While moving on the road, there may be a turn or a curve. The automobile must traverse this turn or curve precisely. The change in the direction of motion should occur very accurately. If that does not happen it may cause a collision. Therefore a steering system must provide accurate control on the motion of the automobile when it is taking a turn or when it is moving on a curved path. The turning of the automobile is usually affected by turning the front wheels. The front axle accommodates this turning of wheel through stub axles. The front axle also accommodates the different components of steering mechanism. Because of this, in case of front wheel drive automobiles, the design of the front wheel becomes quite complicated.
  • Chapter 16

    SUSPENSION SYSTEM Price 2.99  |  2.99 Rewards Points

    Irregularities in the road surface cause shocks and vibrations. If these were transmitted directly to the chassis, the structure would be subjected to excessive vibrations. This would cause discomfort to the occupants of the vehicle, if it is a passenger vehicle and damage the goods, if it is a goods carrying vehicle. The suspension system isolates the structure, as far as possible, from shocks and vibrations due to irregularities in the road surface. Also, it must be achieved without affecting the stability, steering control and general handling qualities of the vehicle. The first requirement is met by using the flexible elements and dampers, while the second is achieved by controlling the relative motions between the unsprung mass and the sprung mass. The unsprung mass is wheel-and-axle assemblies which does not get the benefit of spring action. The rest of the vehicle, above the wheel and axle, is the sprung mass as it gets the benefit of spring action.
  • Chapter 17

    IGNITION SYSTEM Price 2.99  |  2.99 Rewards Points

    The ignition system is responsible for the flow of current across the two electrodes of the spark plug. This is essential to create spark. The spark, thus produced, causes the ignition of fuel. This ignition is converted into flame and causes the combustion of fuel in the cylinder. The process becomes quite complicated as, in automobiles, multi-cylinder engines are used. Considering a four strokes, four cylinder engine (that is very common in an automobile) and say it is running at 4000 revolutions per minute. This means 2000 cycles per minute. Four cylinders mean total 8000 cycles per minute. Therefore, the ignition system is required to produce 8000 sparks per minute. The spark in each plug is required to be produced at right time. It must generate correct amount of heat. Also, the variations in engine operating conditions make the function of ignition system more complex. The improper functioning of ignition system would mean poor fuel economy and engine performance.
  • Chapter 18

    ELECTRICAL AND ELECTRONICS SYSTEMS Price 2.99  |  2.99 Rewards Points

    The electrical system in an automobile produces, stores and delivers the electrical energy for different requirements. The electricity is produced by the alternator. The alternator is a generator that gets mechanical energy in the form of rotation of shaft from the engine. It then transforms it into electrical energy. The electrical energy is stored in a chargeable battery in the form of chemical energy. It is delivered to other components whenever required.
  • Chapter 19

    BATTERY AND CHARGING SYSTEM Price 2.99  |  2.99 Rewards Points

    Battery in an automobile is the source of electric current. The current is needed for so many purposes including energizing the lights, audio/video systems, starting motor, and ignition system. It also supplies required electrical energy to electronic control module (ECM).
  • Chapter 20

    STARTING SYSTEM 232 Price 2.99  |  2.99 Rewards Points

    In an automobile, starting system cranks the engine initially. It has replaced manual effort to crank the engine with the help of cranking rod that was used in ancient days. Initially, the engine requires cranking but once the cycle is completed it starts and runs on its own. In two wheelers, it is common to ‘kick start’ the engine but in recent times a number of manufacturers have introduced ‘button start’. For initial cranking an electric motor is provided that gets electric current as input from battery. The mechanical energy, in the form of rotation of shaft, is transmitted to engine. This provides initial movement of crankshaft, connecting rod and piston. As soon as spark occurs the fuel is ignited and output becomes available from engine. No more cranking is needed and starting system stops working and engine runs on its own. The starting system makes starting of vehicle convenient.
  • Chapter 21

    LIGHTING SYSTEM, ELECTRICAL INSTRUMENTS AND ACCESSORIES Price 2.99  |  2.99 Rewards Points

    Lighting system in an automobile plays a vital role. It is not possible to drive a vehicle in dark hours during night without headlamps, tail lamps and other lights. Apart from head lights and tail lights, indicator lights are required to indicate when vehicle is taking a turn. In case of emergency, flashers are provided. All the indicators flash and convey emergency. Horn, safety devices like air bags, power windows, and adjustable seats are other accessories provided in the modern car. Lights are also provided in engine compartment, glove box and luggage compartment.
  • Chapter 22

    THE CARRIAGE UNIT Price 2.99  |  2.99 Rewards Points

    The carriage unit is required in an automobile to carry all the components including its body. The body is needed to accommodate the passengers. In case of goods carrying vehicle body is used to store the goods to be transported. This is the basic structure that should have enough strength to take up the load of different components and the passengers or goods.
  • Chapter 23

    PASSENGER COMFORT Price 2.99  |  2.99 Rewards Points

    Even a few years back, air-conditioned cars were considered to be luxury and only few could afford them. But as the time passes, more and more cars are equipped with airconditioning and heating systems. These systems make journey very comfortable in any season. In an air-conditioning system, refrigerants carry heat from inside to outside the vehicle. The boiling point of refrigerant depends upon the pressure. If the pressure is high the boiling point is also high. R-134a and R-12 are the commonly used refrigerants. Refrigerant R-134a evaporates at 18°C at a pressure of 476kPa and at 49°C at a pressure of 1214kPa. Similarly, refrigerant R-12 evaporates at 18°C at a pressure of 510 k Pa and at 47°C at a pressure of 1078 k Pa. The temperature and pressure of refrigerant is kept low for absorption of heat and high for dissipation of heat. The heat absorption means conversion of phase from liquid to vapor and heat dissipation means conversion of state from vapor to liquid. Heat absorption means cooling. The absorption process occurs inside the vehicle and dissipation occurs outside the vehicle. Both the processes occur continuously and refrigerant is used in cyclic manner.
  • Chapter 24

    SAFETY AND SECURITY Price 2.99  |  2.99 Rewards Points

    Safety in the title indicates the safety of passenger while security indicates the security of automobile. Safety of passenger is most important. Nothing is lost if passenger comes out safe in an accident. The emphasis while designing, particularly the body of the vehicle, is that body should take the maximum impact of collision. For the extra safety of passenger, the modern automobiles are provided with seat belts, air bags, antilock brakes and traction control. Some of the features are available as standard features and these include seat belts. Other features are available only in high end cars.
  • Chapter 25

    SAFETY AND SECURITY Price 2.99  |  2.99 Rewards Points

    Safety in the title indicates the safety of passenger while security indicates the security of automobile. Safety of passenger is most important. Nothing is lost if passenger comes out safe in an accident. The emphasis while designing, particularly the body of the vehicle, is that body should take the maximum impact of collision. For the extra safety of passenger, the modern automobiles are provided with seat belts, air bags, antilock brakes and traction control. Some of the features are available as standard features and these include seat belts. Other features are available only in high end cars.
  • Chapter 26

    HYBRID CARS Price 2.99  |  2.99 Rewards Points

    The realization that conventional fossil fuel is available in limited quantity and its rising price has produced so many innovations. Small cars were produced to use the available fuel as economically as possible. Similarly, work was undertaken to replace the conventional fuel by non-conventional fuel. The attempts were also made to run the cars on two or more sources of power. These cars that had two or more sources of power were termed as ‘hybrid’.
  • Chapter 27

    THE MOTOR VEHICLE ACT Price 2.99  |  2.99 Rewards Points

    This chapter does not provide any technical information rather it provides the legal aspects of automobiles in India. The chapter finds its place in the book because legal information regarding the automobiles in India is quite relevant. The Motor Vehicle Act has been reproduced here as it is without any comments from the author for the benefit of readers. The attempt has been made to include all the amendments made in the act from time to time but still readers can update their information from the different sites of Government of India available on net.

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