Influencing Factors Of CNC Machining Accuracy
In the precision machining industry, accuracy is an important criterion for measuring quality. So what are the factors that affect the accuracy of CNC machining? Let's take a look at the following points:
1. The first is the error of position influence: it usually refers to the change or deviation degree of the actual surface, axis or symmetry plane of the processed part relative to its ideal position, such as verticality, position degree, symmetry degree, etc.
2. Machine tool error: The error of the machine tool usually refers to the dead angle error. The main reason for the position error is the machining error caused by the clearance and elastic deformation caused by the transmission of the machine tool parts during the machining process, and the position error caused by factors such as the friction force that the tool head needs to overcome during the machining process. In the open-loop system, the position accuracy is greatly affected, while in the closed-loop servo system, the position accuracy mainly depends on the displacement detection.
3. Geometric error: The machining accuracy error caused by the geometric error of CNC machining. In the process of CNC machining, due to the influence of external factors such as external force and heat generated during machining, the geometric accuracy of the machine tool is affected, and the geometric deformation of the parts processed on the machine tool will cause geometric errors. According to research, there are two main reasons for the geometric error of CNC machine tools: internal factors and external factors. The internal factors that cause the geometric error of the machine tool refer to the geometric error caused by the machine tool itself, such as the levelness of the machine tool table, the levelness and straightness of the machine tool guide rail, the geometric accuracy of the machine tools and fixtures, etc. External factors mainly refer to geometric errors caused by the external environment and thermal deformation during processing. For example, geometric errors caused by thermal expansion and deformation of tools or parts during cutting can affect the machining accuracy of machine tools and parts.
4. Cumulative error: From the long-term data analysis and actual operation of part processing, it can be seen 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 positioning accuracy, and the machine tool feed system is the main link that affects the positioning accuracy. The feed system of CNC machine tools usually consists of a mechanical transmission system and an electrical control system. In structural design, the positioning accuracy is related to the mechanical transmission system. In the closed-loop system, the CNC machine tool can usually prevent the position deviation of the main components (such as ball screw and other components) in the feed system through the positioning detection device. However, for an open-loop system, due to many influencing factors and complex conditions, positioning monitoring cannot be performed, so the machining accuracy of CNC machine tools is greatly affected.
The above explanation is the reason for the influence of CNC machining accuracy. I hope it will be helpful to you after reading it. If you want to know more about CNC machining, welcome to read more of our articles!