The main function of the A-grade piston in the excavator engine is to withstand the combustion pressure in the cylinder and transmit this force to the connecting rod, thereby driving the rotation of the crankshaft and outputting power.

The piston is a key component of the excavator engine, and its structure and function are crucial to the performance and lifespan of the engine. The piston is mainly composed of the piston head, piston skirt, and piston pin seat. The piston head directly contacts the combustion chamber and is designed to evenly distribute stress, while the piston skirt is responsible for maintaining the piston in a vertical position during reciprocating motion, ensuring smooth engine operation. The piston pin seat is the supporting part that connects the piston to the connecting rod, achieving power output.

The working environment of the piston is extremely harsh, requiring it to operate under conditions of high temperature, high pressure, high speed, and poor lubrication. The piston, which directly contacts high-temperature gases, can have an instantaneous temperature exceeding 2500K, and the temperature during operation can reach 600-700K, with uneven temperature distribution. In addition, the piston is subjected to significant pressure impact and lateral pressure, especially during the power stroke, under the influence of upper gas pressure. These extreme conditions require the piston to have high precision, high quality, and long lifespan characteristics.

To meet these challenges, the A-grade piston of the excavator engine adopts high-precision machining processes, such as CNC machining, to ensure product accuracy. At the same time, special materials such as aluminum alloy 109, which contains metallic nickel, are used. This material greatly improves the hardness and stiffness of the piston, thereby extending its lifespan. In addition, the addition of wear-resistant rings and other processes effectively reduces wear and improves the product’s lifespan.