6D108 Diesel Engine Piston SA6D108E-2A PC300-6 PC340-6 PC350-6 PC380-6 6222-33-2110 For KOMATSU

Editing and broadcasting of working conditions

The piston operates under conditions of high temperature, high pressure, high speed, and poor lubrication. The piston is in direct 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 temperature of the piston during operation is very high, up to 600~700K at the top, and the temperature distribution is very 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.

With the continuous improvement of diesel engine output power, the thermal and mechanical stresses borne by the piston also increase accordingly, leading to cracking and erosion of the combustion chamber wall at the piston top. Due to the effective improvement of the heat resistance of the aluminum piston top surface by the hard oxidized oxide film, it has an extremely good inhibitory effect on thermal cracking, especially on the tendency of thermal cracking at the combustion chamber edge of direct injection diesel engines. Therefore, High power pistons generally require anodizing treatment.