Analysis of the reasons affecting CNC machining accuracy

Hello, welcome to follow Ruiyimodel. What are the factors that affect the accuracy of CNC machining? What is it? Let us take a look at the following reasons:

 

The first is the position influence error: usually refers to the change or deviation of the mutual position between the actual surface, axis or symmetry plane of the processed part and its ideal position, such as perpendicularity, position, symmetry, etc.

 

Machine tool error: The machine tool error generally refers to the dead angle error. Machining errors due to transmission clearance and elastic deformation of machine tool parts during processing, as well as factors such as friction that the foreman needs to overcome during processing, are the main causes of position errors.

 

The open-loop system has a great influence on the position accuracy, while the position accuracy of the closed-loop follow-up system mainly depends on the displacement detection.

Geometrical error: the machining accuracy error caused by the geometrical error of CNC machining. In CNC machining, the geometric accuracy of the machine tool is affected due to the influence of external force, heat generated during machining and other external factors, and the geometric deformation of the processed workpiece will cause the geometric error of the machine tool. From a theoretical analysis, the reasons for the geometric errors of CNC machine tools are internal and external factors. The internal factors that lead to the geometric errors of the machine tool refer to the geometric errors caused by the factors of the machine tooling itself, such as the levelness of the tooling table, the level and straightness of the guide rail, and the geometric accuracy of the machine tools and fixtures. External factors mainly refer to the geometric errors caused by the external environment and thermal deformation during processing. In the cutting process, the geometric errors caused by the thermal expansion and contraction and deformation of the tool or parts will affect the machining accuracy of the machine tool and the parts.

 

Cumulative error: Through the analysis and actual operation of the long-term data of parts processing, it can be seen that the machining accuracy error caused by the positioning of the CNC machining machine tool. In CNC machine tools, the position of the machine tool has a great influence on machining accuracy. In terms of structure, the machining error of CNC machine tools mainly comes from positioning accuracy, and the machine tool feed system is its main link. CNC machine tool feed system generally consists of two parts: mechanical transmission and electrical control. In the mechanism design, the positioning accuracy mainly depends on the mechanical transmission system. Under normal circumstances, in a closed-loop system, the CNC machine tool can prevent the position deviation of the main components of the feed system such as the ball screw and other components through the positioning detection device. But for the open-loop system, due to many influencing factors and complex working conditions, it is impossible to locate and monitor it, which affects the machining accuracy of CNC machine tools.

The above is the reason for the influence of CNC machining accuracy. I hope it can help you. If you want to know more about CNC machining, please read this article.

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