The function of the piston is to bear the gas pressure and pass it to the connecting rod through the piston pin to drive the crankshaft to rotate. The top of the piston is also a part of the combustion chamber.
Function of piston:
1. The piston ring plays a sealing role in the cylinder. The linkage connecting rod makes the crankshaft rotate in one direction to achieve the purpose of continuous piston work.
2. During the intake stroke, the piston moves downward, the intake valve opens, and the suspected mixture of gasoline and air is sucked into the cylinder.
3. During the compression stroke, the intake valve is closed, the piston moves upward, and the combustible mixture is compressed.
4. During the working stroke (or power stroke, burst stroke), the piston compresses to the top, and the spark is generated by high voltage current in the spark plug. The spark causes the combustible mixture to ignite, and the temperature is as high as 20001, which makes all the gases expand rapidly and produce extremely high pressure (about 30-40 kg / cm2), which pushes the piston downward and makes the crankshaft rotate by the action of the connecting rod.
5. During the exhaust stroke, the piston moves upward and the exhaust valve opens. The exhaust gas after combustion is squeezed by the piston and discharged by the exhaust valve.
6. It can be seen that the piston of the engine transmits the work done by the engine through the continuous cycle of exhaust, intake, compression and explosion.