Principal parts

THE INTERNAL COMBUSTION ENGINE.

TEXT A

THE INTERNAL COMBUSTION ENGINE

LESSON 1

TEXT A THE INTERNAL COMBUSTION ENGINE.

PRINCIPAL PARTS

TEXT B THE BASIC SYSTEMS OF THE INTERNAL

COMBUSTION ENGINE

TEXT C ENGINE SERVICING

GRAMMAR REVISION THE PASSIVE VOICE, PARTICIPLE I,

PARTICIPLE II

It is known¹ that for a long time scientists were looking for ways² to convert fuel directly into the power. As a result³ they invented the internal combustion engine in which the process of fuel combustion takes place. The fuel burns and provides the power that makes⁴ an automobile move.

The fuel is stored in a tank connected to the carburetor by a small diameter pipe. The carburetor is a device in which the fuel is mixed with air in the correct proportions. The carburetor is attached to the inlet pipe through⁵ which the air-fuel mixture moves into the intake valve of the cylinder. The explosive mixture is compressed by the piston, and then it is ignited by the electric spark in the combustion chamber. Heat and gases are produced during the process of combustion. The gases force the piston down⁶ and escape through the exhaust valve. The piston moves up and down in the cylinder. The extreme⁷ positions of the piston are called the top dead centre (TDC) and the bottom dead centre (BDC). The piston movement from TDC to BDC and from BDC to TDC is called the piston stroke.

There are two basic mechanisms in the internal combustion engine. The first one is the crank mechanism that takes the pressure of gases in the cylinder during the fuel combustion and changes the reciprocating motion of the piston into the rotary motion of the crankshaft. The crank mechanism consists of cylinder block, piston and piston rigs, connecting rod, crankshaft and flywheel and crankcase. The piston is connected to the crankshaft by means of⁸ the connecting rod. On the one end of the crankshaft there is a gear that drives the crankshaft of the engine. The function of the camshaft is to open and close the valves of the cylinder. At the opposite end of the crankshaft there is a flywheel that transmits power to the transmission system of the engine.

The crankshaft is carried⁹ on the main bearings. The crankcase forms the bottom of the cylinder block. It protects its parts and keeps¹⁰ the oil.

The other mechanism of the engine is the gas-distributive mechanism. It consists of a camshaft, a gear drive and valves. The main function of this mechanism is to force the air-fuel mixture into the cylinder and to exhaust the gases when the operating cycle is over.

There are 4 basic systems in the internal combustion engine. They are the cooling system, the lubricating system, the fuel system and the electrical system.

Дата добавления: 2014-10-17