Machine tool processing and mechanical processing

In China's modern mechanical equipment and its workpiece manufacturing enterprises, CNC machine tools have ample space for technical application, bringing significant economic benefits to China's mechanical production and processing technology. In the process of applying CNC lathe equipment to carry out the production and processing of mechanical equipment workpieces, the precision level of the processing technology that the CNC lathe equipment itself possesses has a significant impact on the actual technical quality and performance status of the mechanical equipment workpieces. Therefore, enhancing the precision of CNC lathes in the production and processing of mechanical parts is of great significance for improving the quality of the production and processing of mechanical and electrical parts in our country. This article thus discusses the influencing factors of the machining accuracy of CNC lathes and their optimization strategies.

I. Influencing Factors of Machining Accuracy of CNC Lathes

The influence of positional errors in CNC machine tool processing on machining accuracy

Positional error refers to the variation or deviation degree of the actual surface, axis or symmetry plane of the processed part from its ideal position, such as perpendicularity, positional accuracy, symmetry, etc. Positional errors in CNC machine tool processing usually refer to dead zone errors. The main causes of positional errors are processing errors due to the clearance and elastic deformation generated during transmission of machine tool parts, as well as positional errors caused by factors such as the need for the tool head of the machine tool to overcome friction during processing. In the process of applying modern CNC lathe equipment to carry out mechanical workpiece processing operations, usually, if processing technicians want to achieve precise control of the spatial movement position of mechanical workpieces, they must rely on servo motor equipment to apply driving force to the ball screw technical components in the CNC lathe processing system. If the ball screw components have transmission errors, it will be direct

It has a significant adverse impact on the precision level of mechanical workpiece processing operations. The existence of this phenomenon is also the main objective cause of the positioning accuracy error in CNC lathe equipment.

2. Machining accuracy errors caused by geometric errors in CNC machine tool processing

In the processing of CNC machine tools, due to the influence of external forces and heat generated during processing on the cutting tools and fixtures, the geometric accuracy of the machine tool will be affected to a certain extent. The parts processed on the machine tool will undergo geometric deformation, thereby generating geometric errors. According to relevant research and analysis, the geometric errors produced by CNC machine tools are caused by both internal and external factors. Internal factors refer to geometric errors caused by the machine tool itself, such as the levelness of the machine tool's worktable surface, the levelness and straightness of the machine tool's guide rails, and the geometric accuracy of the machine tool's cutting tools and fixtures, etc. External factors mainly refer to several kinds of errors generated under the influence of external environment and thermal deformation during the processing. For instance, during the cutting process of tools or components, due to thermal expansion and deformation, geometric errors occur, which affect the processing accuracy of machine tools and components.

3. Machining accuracy errors caused by machine positioning in CNC machine tool processing

Through the analysis of long-term component processing data and practical operations, it can be known that machine tool positioning has a significant impact on the processing accuracy of CNC machine tools. The machining errors of CNC machine tools, from a structural perspective, are mostly caused by positioning accuracy. Among them, the feed system of the machine tool is the main link affecting positioning accuracy. The feed system of a CNC machine tool is usually composed of two parts: the mechanical transmission system and the 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 having positional deviations, such as ball screws and other components, through positioning detection devices. For open-loop systems, due to the numerous influencing factors and complex situations, it is difficult to conduct positioning and monitoring, thus having a significant impact on the machining accuracy of CNC machine tools.

Ii. Optimization Strategies for the Machining Accuracy of CNC Lathes

1. Improve processing accuracy by controlling the original error of CNC machine tools

To enhance the machining accuracy of CNC machine tools, controlling the original error of CNC machine tools is an important countermeasure. A systematic analysis should be conducted on the possibility of generating original errors, and corresponding improvement measures should be formulated based on the causes and types of errors. During the processing, the position accuracy and geometric accuracy of CNC machine tools have a significant impact on the processing accuracy of components. It is necessary to reduce the influence of position errors and geometric errors on parts through position control and geometric accuracy control. At the same time, for the deformation errors generated during the processing, methods such as air cooling and water cooling should be used to control the thermal deformation during the processing and reduce the impact of thermal deformation errors on processing accuracy.

2. Design the core components of the machine tool reasonably to avoid positioning errors

The positioning accuracy of machine tools has a significant impact on the accuracy of components. The straightness and levelness of core components that affect the positioning accuracy of machine tools, such as the feed system, guide rails, and worktable surface, etc. When designing CNC machine tools, it is necessary to rationally select core components. For instance, when choosing ball screws that are widely used in machine tools at present, the precision of the ball screws should be fully considered, and relatively mature ball screw technologies should be selected and installed. The support of the ball screw cannot be ignored either. The support of the ball screw is closely related to the transmission accuracy of the system. The support of the ball screw is mainly determined by the axial load and the rotational speed, which has an important impact on the processing accuracy of the CNC lathe. Usually, high-precision fixing and support methods are selected.