1. 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 processed part relative to its ideal position, such as perpendicularity, position, 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.
2. Machining accuracy error caused by geometric error
In CNC machine tool processing, the geometric accuracy of the machine tool is affected due to the influence of external forces and heat generated by the tool and fixture on the machine tool, and the parts processed on the machine tool are geometrically deformed, 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.
3. Machining accuracy error caused by machine 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 is usually composed 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 situations, positioning monitoring cannot be performed, so it has a greater impact on the machining accuracy of CNC machine tools.