INTRODUCTION OF AUTOMOTIVE ENGINEERING :
IC ENGINE : The piston engine is known as an internal-combustion heat-engine. The concept of the piston engine is that a supply of air-and-fuel mixture is fed to the inside of the cylinder where it is compressed and then burnt. This internal combustion releases heat energy which is then
converted into useful mechanical work as the high gas pressures generated force the piston to move along its stroke in the cylinder. It can be said, therefore, that a heat-engine is merely an energy transformer.
To enable the piston movement to be harnessed, the driving thrust on the piston is transmitted by means of a connecting-rod to a crankshaft whose function is to convert the linear piston motion in the cylinder to a rotary crankshaft movement . The piston can thus be made to repeat its movement to and fro, due to the constraints of the crankshaft crankpin’s circular path and the guiding cylinder.AUTOMOTIVE ENGINEERING
The backward-and-forward displacement of the piston is generally referred to as the reciprocating motion of the piston, so these power units are also known as reciprocating engines.AUTOMOTIVE ENGINEERING
FOUR STOKE ENGINE :
The first internal-combustion engine to operate successfully on the four-stroke cycle used gas as a fuel and was built in 1876 by Nicolaus August Otto, a self-taught German engineer at the Gas-motoreufabrik Deutz
factory near Cologne, for many years the largest manufacturer of internal-combustion engines in the world. It was one of Otto’s associates – Gottlieb Daimler – who later developed an engine to run on petrol which was
described in patent number 4315 of 1885. He also pioneered its application to the motor vehicle.
Petrol engines take in a flammable mixture of air and petrol which is ignited by a timed spark when the charge is compressed. These engines are therefore sometimes called spark-ignition (S.I.) engines. These engines require four piston strokes to complete one cycle: an air-and-fuel intake stroke moving outward from the cylinder head, an inward movement towards the cylinder head compressing the charge, an outward
power stroke, and an inward exhaust stroke.AUTOMOTIVE ENGINEERING