Editing and broadcasting of working conditions

The piston operates under conditions of high temperature, high pressure, high speed, and poor lubrication. The piston is directly in contact with high-temperature gas, and the instantaneous temperature can reach more than 2500K. Therefore, the piston is seriously heated and the heat dissipation condition is poor, so the piston is at a high temperature when working, with the top up to 600-700K, and the temperature distribution is uneven; The top of the piston bears a large amount of gas pressure, especially the maximum working stroke pressure, which can reach as high as 3-5 MPa for gasoline engines and 6-9 MPa for diesel engines. This causes the piston to have an impact and bear the effect of lateral pressure; The piston moves back and forth in the cylinder at a high speed (8-12 m/s), and the speed is constantly changing, which generates a large inertial force, causing the piston to be subjected to a large additional load. When the piston operates under such harsh conditions, it will deform and accelerate wear, as well as generate additional loads and thermal stresses, while also being subjected to chemical corrosion from gas.

The entire piston can be mainly divided into three parts: piston crown, piston head, and piston skirt.

The main function of the piston is to withstand the combustion pressure in the cylinder and transmit this force to the crankshaft through the piston pin and connecting rod. In addition, the piston also forms a combustion chamber together with the cylinder head and cylinder wall.