The machining accuracy of the outer profile of the piston has a decisive influence on the running performance, fuel consumption and exhaust emissions of the internal combustion engine. The piston works in the harsh environment of high temperature, high pressure and periodic impact, and the force deformation and thermal deformation are very serious and uneven. In order to adapt the outer shape of the piston to the cylindrical cylinder in the working state, the outer shape of the piston at normal temperature is usually designed as a special-shaped surface. The shape of the section along its own axis is approximately waist drum shape, and the shape of the section perpendicular to its own axis is approximately ellipse. In order to meet the requirements of use, the machining method of the outer circle of the piston is generally turning. To turn a piston with a special-shaped section, a mechanical imitation method is traditionally used. However, it is difficult to manufacture by mold, easy to wear, low frequency response, and difficult to replace the piston, which seriously restricts the improvement of processing accuracy and processing efficiency. In recent years, both at home and abroad have been studying the application of numerical control technology to the machining of the outer circle of the piston, and great progress has been made. The PTC series piston cylindrical CNC turning system developed by us has been used by nearly 30 domestic enterprises and has achieved good economic benefits.
