What is the structure of an automobile engine?

The engine consists of crank-connecting rod mechanism, valve train, cooling, lubrication, ignition, oil supply and starting system.

The main components are cylinder block, cylinder head, piston, piston pin, connecting rod, crankshaft and flywheel. The working cavity of reciprocating piston internal combustion engine is called cylinder, and the inner surface of cylinder is cylindrical. A piston reciprocating in the cylinder is hinged with one end of a connecting rod through a piston pin, and the other end of the connecting rod is connected with a crankshaft, which is supported by a bearing on the cylinder block and can rotate in the bearing to form a crank-connecting rod mechanism.

When the piston reciprocates in the cylinder, the connecting rod pushes the crankshaft to rotate. On the contrary, when the crankshaft rotates, the connecting rod journal moves circularly in the crankcase and drives the piston to move up and down in the cylinder through the connecting rod. Every time the crankshaft rotates and the piston moves up and down, the volume of the cylinder is constantly changing from small to large, and then from large to small, and so on.

The top of the cylinder is closed with a cylinder head. The cylinder head is equipped with an intake valve and an exhaust valve. Air is charged into the cylinder and discharged from the cylinder by opening and closing the intake valve and the exhaust valve. The opening and closing of the intake and exhaust valves are driven by the camshaft. Camshaft is driven by crankshaft through toothed belt or gear.

Extended data:

Engine classification:

I. Classification by fuel:

It can be divided into diesel engine, gasoline engine, natural gas engine and oil-electric mixer.

Second, according to the number of cycles:

1, two-stroke engine: the piston moves for two strokes or the crankshaft rotates once to complete a working cycle in the cylinder.

2. Four-stroke engine: the piston moves four strokes or the crankshaft rotates twice to complete a working cycle in the cylinder.

Both engines can be driven by various fuels (including electric oil, diesel oil and liquefied petroleum gas).

Third, according to the cooling mode:

1, water-cooled engine: using water as cooling medium.

2. Air-cooled engine: Air is used as cooling medium.

Four: according to the ignition mode:

1, compression ignition engine: use the high temperature generated by compressed air in the cylinder to make the fuel spontaneously ignite. Such as a diesel engine.

2. Ignition engine: The fuel is forcibly ignited by the electric spark from the spark plug, so that the fuel is forcibly ignited and burned. Such as gasoline engines and gas engines.

Baidu encyclopedia-automobile engine

Baidu Encyclopedia-Engine