Six knowledge points of CNC machining

CNC machining (generally CNC machining usually refers to computer digital control precision machining, CNC machining lathe, CNC machining milling machine, CNC machining boring and milling machine, etc.) In the machining process of the center, one thing is very important, and that is in the preparation [biān zhì] During procedures and operations, we must avoid [bì miǎn] causing the CNC machining center to bump [kē pengr, kē pèng]. Because the price of a CNC machining center is very expensive, ranging from several hundred thousand yuan to as many as one million yuan, repairing is difficult and expensive. However, the onset of bumps has certain rules to follow and can be avoided, mainly as follows.

　　1, use computer to imitate (copy) simulation system

　　 With the development of computer technology and the continuous expansion of CNC machining education, there are more and more CNC machining imitating simulation systems, and their functions are becoming more and more perfect. Therefore, it can be used to start to view the program and observe the movement of the tool to determine whether there is a possibility of collision.

　 2. Utilize the imitation display function of CNC machining center (function)

　　 Generally, more advanced CNC machining centers have graphics display functions. After inputting the program, you can call the graphic simulation display function to observe the tool's motion track (called trajectory) specifically to check whether the tool may collide with the workpiece or fixture.

　　3. Use the dry run function of CNC machining center

　　Using the dry run function of the CNC machining center, you can check whether the tool path is correct. After the program is input to the CNC machining center, you can install the tool or workpiece, and then press the dry run button (button). At this moment, the spindle does not rotate, and the worktable automatically runs according to the program track. At this moment, you can find out whether the tool may be with the workpiece or fixture collide. However, in this case, it is necessary to ensure that the tool cannot be installed when the workpiece is installed; when the tool is installed, the workpiece cannot be installed, or bumps will occur.

　　4. Use the lock function of CNC machining center

　　The general CNC machining center has a lock function (full lock or single-axis lock). After inputting the program, lock the Z-axis, and judge whether there will be any bumps through the coordinate value of the Z-axis. The use of this function should avoid operations such as tool change, otherwise the program cannot be passed through.

　　5. The coordinate system and tool offset settings (set up) must be correct

　 When starting the CNC machining center, the CNC machining center reference point must be set. The working coordinate system of the CNC machining center should be consistent with the programming, especially the Z-axis direction. If you make a mistake, the possibility of the milling cutter colliding with the workpiece is very high. In addition, the setting of tool length compensation must be correct, otherwise, it is either empty machining or collision.

　　6, improve programming skills (technique)

　　 Programming is a crucial part of CNC machining. Improving programming skills can avoid unnecessary bumps to a large extent.

For example, milling [xǐ xiāo metal cutting with a milling machine] workpiece cavity, when the milling is completed, the milling cutter needs to be quickly retracted to 100mm above the workpiece, if programming with N50 G00 X0 Y0 Z100, then the CNC machining center will move the three-axis linkage , The milling cutter may collide with the workpiece, causing damage to the tool and the workpiece, which will seriously affect the accuracy of the CNC machining center. At this time, the following program can be used: N40 G00 Z100; N50 X0 Y0; that is, the tool first retracts 100mm above the workpiece Place, and then come back to program the zero point so that there is no bump.

　　 In short, mastering the programming skills of machining centers can better improve machining efficiency and machining quality, and avoid unnecessary errors in machining. This requires us to continue to sum up experience in practice (experience), continuous improvement, so as to further strengthen and improve the programming and processing capabilities.