With the increasingly stringent requirements for engine power, economy, environmental protection, and reliability of the entire vehicle, Copeland Discus type Piston has developed into a collection of light-weight and high-strength new materials, special-shaped outer circular composite surfaces, and special-shaped pins. A high-tech product that integrates many new technologies such as holes to ensure the heat resistance, wear resistance, stable guidance and good sealing function of the Copeland Discus type Piston, reduce the frictional power loss of the engine, reduce fuel consumption, Noise and emissions.

In order to meet the above functional requirements, the outer circle of the Copeland Discus type Piston is usually designed as a special-shaped outer circle (convex to ellipse), that is, the cross section perpendicular to the axis of the piston is an ellipse or a modified ellipse, and the ellipticity is fixed along the axis. The ellipticity accuracy is 0.005mm; the outer contour of the piston longitudinal section is a high-order function fitting curve, and the contour accuracy is 0.005～0.01mm; in order to increase the bearing capacity of the piston and increase the engine’s power per liter, it is usually The pin hole of the high-load piston is designed into a micro-inner cone type or a normal stress curved surface type (special-shaped pin hole), the size accuracy of the pin hole reaches IT4 level, and the contour accuracy is 0.003mm.

Copeland Discus type Piston, as a typical automotive key component, has strong process characteristics in cutting. China's Copeland Discus type Piston manufacturing industry usually consists of general-purpose machine tools and special equipment combining piston process characteristics to form a machining production line. Therefore, special equipment has become the key equipment for Copeland Discus type Piston cutting processing, and its function and accuracy will directly affect the final product The key characteristics of the quality index.