In the process of machining and cutting, CNC lathe suffers from elastic deformation in the direction of force due to the action of cutting force, which is the phenomenon of knife yielding as we often say. Corresponding methods should be adopted to deal with this kind of deformation on the cutter. When finishing, the cutter should be sharp. On the one hand, it can reduce the resistance caused by the conflict between the cutter and the workpiece, on the other hand, it can improve the heat dissipation ability of the cutter when cutting the workpiece.

     Then reduce the residual internal stress on the workpiece. With the rapid development of science and technology, the society has higher and higher requirements on the structure, function, accuracy, power and types of mechanical products, and the proportion of single and small batch products is increasing. The traditional general and special machine tools and process equipments can not meet the requirements of high quality, high power and diversified processing.

     Because of its high power, high precision and high flexibility, CNC lathe has been widely used in the mechanical manufacturing industry. It has become one of the most widely used CNC machine tools. It is difficult to process thin-walled CNC lathe, especially the inner hole, because it is in the cutting process.

     The thin wall is simply deformed by cutting force. Then it leads to the phenomenon of "waist shape" with small ellipse or center and big two ends. Other thin-walled sleeves are prone to thermal deformation due to poor heat dissipation during processing, resulting in errors in standard and shape and position. How to reduce the influence of cutting force on workpiece deformation is an important problem to be dealt with, which can not meet the requirements of drawings.