Piston is a core component of the internal combustion engine , and its main functions can be summarized in the following aspects:

Sealing effect: Piston and cylinder wall and cylinder head together to form the combustion chamber, and withstand high temperature and high pressure gas action. The tight fit between the piston ring and the cylinder wall ensures the sealing of the combustion chamber, prevents the leakage of combustible mixture or high temperature and high pressure gas into the crankcase, and also prevents the oil from entering the combustion chamber.

Transfer power: During the working process of the engine, the top of the piston bears the gas pressure, and the force is transmitted to the connecting rod through the piston pin, which drives the crankshaft to rotate and realizes the conversion of heat energy to mechanical energy. This is a key part of the engine's power output.

Change the cylinder volume: the piston in the cylinder for reciprocating linear movement, thereby changing the volume of the cylinder, to achieve the engine intake, compression, work and exhaust four strokes. The continuous cycle of these four strokes is the basis for the operation of the engine.

Supporting role: The piston is connected with the big head of the connecting rod through the piston pin, which supports the connecting rod and bears the lateral force from the connecting rod. This support ensures stable movement of the piston in the cylinder and reduces vibration and wear caused by lateral forces.

In summary, the Piston is a vital component in the internal combustion engine, and its sealing, power transfer efficiency, and ability to change cylinder volume directly affect engine performance and efficiency. Therefore, when designing and manufacturing pistons, it is necessary to fully consider the choice of materials, the optimization of the structure and the improvement of the manufacturing process to ensure that the piston can meet the various working requirements of the engine.