CNC machining is to use the automatic control system to install digital program flow commands to control the automatic start and stop, reversing and speed change of the CNC machine tool bearings. You can choose the CNC blade, you can change the drilling amount and walking motion trajectory of the CNC blade, and perform various auxiliary postures required for life-long machining. CNC machining can greatly reduce the number of work clothes, and produce parts with complex machining methods, and only need to change the process flow. CNC machining is relatively stable and will not cause machining errors. So what are the reasons that affect the accuracy of CNC machining? Let us understand together:
It can be seen from the long-term data analysis and actual operation of parts machining that the machining accuracy error caused by the positioning of the CNC machining machine tool. The positioning of the machine tool has a great influence on the machining accuracy of the CNC machine tool. From the structural point of view, the machining error of CNC machine tools is mainly caused by the accuracy level, and the machine tool feed system is the key stage that affects the accuracy level. The feed system of a CNC machine tool is generally composed of a mechanical transmission system and an electrical control system. In the overall design, the accuracy level is related to the mechanical transmission system. In the closed-loop control system, CNC machine tools can generally avoid the position error of key components in the feed system (such as ball screws and other components) based on the positioning inspection equipment. As everyone knows, for the open-loop system, because of many influencing factors and complex conditions, it is impossible to carry out positioning detection, so the machining accuracy of CNC machine tools is greatly affected.
The influence of CNC machining position error on machining accuracy. Position error refers to the transition or offset level of the specific surface, centerline or symmetry face of the processed part relative to its idealized position, such as flatness, symmetry, symmetry, etc. The position error in CNC machining generally refers to the overcurrent protection error. The key reason for the position error is the machining error caused by the gap and elastic deformation caused by the transmission system in the whole process of the machine tool parts machining, and the position error caused by the sliding friction force that the special tool head needs to get rid of during the production process. In the open-loop system, the position accuracy is greatly affected, while in the closed-loop control headlight system, the key to the position accuracy lies in the offset inspection.
The machining accuracy error caused by the geometric figure error of CNC machining. In the machining of CNC machine tools, due to the influence of external forces such as external forces and heat generated during machining, the geometric precision of the machine tool is affected. The geometric deformation of the parts processed on the machine tool will cause geometric errors. According to scientific research, there are two key reasons for the geometric error of CNC machine tools: internal factors and external factors. The internal elements that cause machine tool geometric errors refer to the geometric errors caused by the machine tool itself, such as the flatness of the machine tool table, the flatness and parallelism of the machine tool rails, the geometric accuracy of the machine tools and fixtures. The key to external factors refers to the geometric error caused by environmental factors and thermal deformation in the production process. For example, the geometric error caused by the thermal deformation and deformation of the CNC blade or part during the whole drilling process will affect the machining accuracy of the machine tool and the part.