Principle and structure of internal combustion engine

Working principle of internal combustion engine:

1. The cylinder head is provided with an intake passage and an exhaust passage, and exhaust valves are arranged in the intake passage and the exhaust passage. Fresh charge (air or combustible air and fuel mixture) is charged into the cylinder through the air cleaner, intake pipe, intake passage and intake valve. The expanded gas passes through the exhaust valve, exhaust pipe and exhaust pipe, and finally is discharged into the atmosphere through the exhaust muffler.

2. The opening and closing of the intake and exhaust valves are controlled by the intake and exhaust cams on the camshaft through transmission parts such as tappets, push rods, rocker arms and valve springs. This group of parts is called the valve mechanism of internal combustion engine. Usually, the air intake and exhaust system consists of air filter, air intake pipe, exhaust pipe and exhaust muffler.

Structure diagram of internal combustion engine:

1. In a broad sense, internal combustion engines include not only reciprocating piston internal combustion engines, rotary piston engines and free piston engines, but also rotary impeller jet engines, but internal combustion engines usually refer to piston internal combustion engines.

2. Reciprocating piston is the most common internal combustion engine. Piston internal combustion engine mixes fuel with air and burns it in its cylinder. The released heat energy makes the cylinder produce high temperature and high pressure gas. The gas expands to push the piston to do work, and then outputs mechanical work through crank-connecting rod mechanism or other mechanisms to drive the driven machinery to do work.

3. Diesel engines and gasoline engines are very common. Convert internal energy into mechanical energy and change internal energy by doing work.