Automatic Knife and Tool Wear Compensation Method for Computer Numerical Control Milling Machine
Computer numerical control (CNC) milling machines have become all-purpose tools in the field of machining due to their excellent accuracy, precision, and repeatability. With the development of machining technology, these machines have been equipped with automatic tool change systems, which not only improve the processing efficiency, but also reduce labor costs. Generally speaking, the automatic tool change system of CNC milling machines is mainly composed of tool magazines and tool holders. The tool magazines can store multiple tools at the same time and easily exchange between different tools. The tool holders can not only firmly clamp the tool, but also realize the automatic tool compensation function.
However, due to the frequent replacement of tools, the wear of the cutting edge of the tools will always be there. The tool wear will affect the accuracy of the machining, which will lead to poor machining surface finish. In order to solve this problem, the automatic tool wear compensation method of CNC milling machine has come out. This method can detect the tool wear automatically, and then compensate for the tool wear by suitable parameters, so as to maintain the accuracy of the cutting process.
The general principle of automatic tool wear compensation of CNC milling machines is to detect the tool edge wear degree by measuring instruments, and then adjust the tool compensation parameters according to the actual wear degree. At present, the common tools wear detection are mainly optical detection and touch detection. Optical detection means using optical instruments to check the wear degree of the tool, mainly using a displacement instrument. The displacement instrument can directly measure the knife edge wear degree, and then manually adjust the tool compensation parameters. This detection method is simple, but the adjustment is complicated and the accuracy is relatively low.
The touch detection means using a touch sensor to detect the tool edge wear. This method can realize automatic detection and control, which is beneficial to maintain the machining accuracy of the parts surface. First of all, the touch sensor should be properly arranged on the automatic tool compensation device. When the spindle moves and the tool approaches the touch sensor, the tool wear change can be detected in real time. If the wear degree reaches a certain value, the signal of the touch sensor will be sent to the CNC system. According to the signal, the CNC system can automatically adjust the parameters, thus achieving the effect of automatic tool wear compensation.
In addition, in order to realize the efficient and accurate automatic tool wear compensation, the CNC milling machine must be equipped with the corresponding automatic tool compensation device and the appropriate programming software. At present, the most widely used automatic tool compensation device is the tool wear auto compensation system. The device consists of a signal sampling device, a tool compensation control system, and a tool compensation operation panel. The device is connected to the CNC system and the spindle of the machine tool. When the machine tool is running, the signal sampling device can detect the tool wear degree in real time, and then the compensation system will automatically adjust the appropriate parameters according to the calculated tool wear degree to achieve the tool wear compensation.
In summary, the automatic tool wear compensation method of CNC milling machines is beneficial to reduce the labor intensity in the cutting process, and can maintain the accuracy of the machined parts more effectively. Therefore, although the initial investment is high, it will bring great economic benefits to the enterprise in the long run.
