Causes of unstable machining accuracy during CNC machining
CNC machining technology has been widely used in modern manufacturing due to its high efficiency and precision. However, in the actual production process, instability of machining accuracy often leads to deterioration of product quality and reduction of production efficiency. Therefore, an in-depth study of the causes of unstable machining accuracy in CNC machining and its solution is of great significance to improving production efficiency and product quality.
Causes of unstable machining accuracy.
Precision of mechanical equipment
The mechanical structure and moving parts of CNC machines are key factors affecting machining accuracy. Insufficient rigidity of the machine, wear of guideways, aging of bearings, etc. will cause vibration during machining, affecting the trajectory and machining accuracy. In addition, thermal deformation of the machine is an important factor. After long-term operation, the increase in the temperature of the machine will cause the expansion of the metal material, which will affect the relative position of the tool. and the workpiece.
Tool selection and wear
The tool is the tool that is directly involved in cutting in CNC machining, and its selection and condition directly affect the machining accuracy. The material, geometry and coating of the tool will affect the cutting performance. If the tool is severely worn, the geometry of the cutting edge will change, causing the cutting force to increase and the cutting temperature to rise, which will affect the machining accuracy. Therefore, regular inspection and replacement of tools are important measures to ensure the machining accuracy.
Setting the machining parameters
Setting the machining parameters such as cutting speed, feed rate and cutting depth in CNC machining also affects the machining accuracy. Unreasonable parameter setting may cause poor contact between the tool and the workpiece, resulting in machining defects. For example, too high a cutting speed may cause the tool to overheat, and too low a feed rate may cause insufficient cutting, which will affect the surface quality and dimensional accuracy. Therefore, reasonable setting of the machining parameters is the key to ensuring the machining accuracy.
Fixture and workpiece fixture design.
The workpiece must remain in a stable fixed state during the machining process. Incorrect fixture design or poor workpiece fixation will cause the workpiece to move during machining, which will affect the machining accuracy, especially for workpieces that are processed multiple times. Complex shapes, fixture design, and workpiece fixation method are even more important. Using high-precision fixtures and reasonable fixation methods can effectively reduce the workpiece displacement and improve the machining accuracy.
Technical level of operators
In CNC machining, not only the productivity of equipment and materials, but also the technical level of operators plays an important role. Operators need to have certain professional knowledge and practical experience, be able to set machining parameters reasonably, select suitable tools, and promptly detect and solve problems that arise during the machining process. Training and improving the technical level of operators can effectively reduce the instability of machining accuracy caused by human factors.
Environmental factors
Finally, environmental factors can also affect the accuracy of CNC machining. For example, changes in temperature and humidity can cause thermal expansion of machines and workpieces, which in turn affects the machining accuracy. In addition, the cleanliness of the workshop, air flow, etc. can also affect the stability during machining. Therefore, maintaining a good machining environment is an important guarantee for ensuring machining accuracy.
