With the increasingly strict requirements for the power, economy, environmental protection, and reliability of the engine in the entire vehicle, the piston has developed into a high-tech product that integrates multiple new technologies such as lightweight and high-strength materials, irregular cylindrical composite surfaces, and irregular pin holes. This ensures the heat resistance, wear resistance, stable guidance, and good sealing function of the piston, reduces the friction power loss of the engine, and reduces fuel consumption Noise and emissions. To meet the above functional requirements, the outer circle of the piston is usually designed as an irregular outer circle (convex to elliptical), that is, the transverse section perpendicular to the piston axis is an ellipse or a modified ellipse, and the ellipticity changes according to a certain pattern along the axis direction (as shown in Figure 1), with an accuracy of 0.005mm for ellipticity; The outer profile of the piston longitudinal profile is a fitting curve of a higher-order function, with a contour accuracy of 0.005-0.01mm; In order to improve the load-bearing capacity of the piston and increase the engine's power output, the pin hole of the high load piston is usually designed as a micro inner cone type or a normal stress curved surface type (irregular pin hole), with a pin hole size accuracy of IT4 level and a contour accuracy of 0.003mm.

As a typical key component of automobiles, pistons have strong technological characteristics in cutting processing. The domestic piston manufacturing industry usually consists of a machining production line composed of universal machine tools and specialized equipment that combines the characteristics of piston technology. Therefore, specialized equipment has become the key equipment for piston cutting processing, and its function and accuracy will directly affect the quality indicators of the key characteristics of the final product.