The precision problem in the machining of CNC lathe parts

u200b01. The influence of position error of CNC lathe parts on machining accuracy Position error refers to the amount of change or deviation between the actual surface, axis or symmetry plane of the part after machining relative to its ideal position, such as verticality, position Degree, symmetry, etc. The position error in CNC machine tool processing usually refers to the dead zone error. The cause of the position error is mainly due to the gap and elastic deformation generated during the transmission of the machine tool parts during the processing, and the tool head of the machine tool needs to overcome the friction force during processing. Factors such as lead to position error. In the open-loop system, the position accuracy is greatly affected, while in the closed-loop follow-up system, it mainly depends on the displacement detection. u200b02. Machining accuracy errors caused by geometric errors In CNC machine tool processing, due to the influence of external forces and heat generated during processing on the tool and fixture, the geometric accuracy of the machine tool is affected, and the parts processed on the machine tool produce geometry Deformation, resulting in geometric errors. According to research, the main reasons for the geometric errors of CNC machine tools are nothing more than the following two: internal factors and external factors. The internal factors of the machine tool's geometric errors refer to the geometric errors caused by the machine's own factors, such as the levelness of the machine table, the levelness and straightness of the machine tool guide rails, and the geometric accuracy of the machine tools and fixtures. External factors mainly refer to the geometric errors generated under the influence of factors such as the external environment and thermal deformation during processing. For example, during the cutting process of tools or parts, due to thermal expansion and deformation, geometric errors occur, which affect the processing of machine tools. Precision and machining precision of parts. 03. Machining accuracy errors caused by machine tool positioning Through long-term data analysis and practical operation of parts processing, it can be seen that machine tool positioning has a greater impact on the machining accuracy of CNC machine tools. From the structural point of view, the machining errors of CNC machine tools are mostly caused by positioning accuracy. Among them, the feed system of the machine tool is the main link that affects the positioning accuracy. The feed system of a CNC machine tool usually consists of two parts: a mechanical transmission system and an electrical control system. The positioning accuracy is related to the mechanical transmission system in the structural design. In a closed-loop system, CNC machine tools can usually prevent the main components in the feed system from generating position deviations, such as ball screws and other components, through positioning detection devices. As for the open-loop system, due to many influencing factors and complicated conditions, positioning monitoring cannot be carried out, so it has a greater impact on the machining accuracy of CNC machine tools.