Views:6 Author:Site Editor Publish Time: 2021-08-23 Origin:Site
When milling complex workpieces, the use of CNC milling cutters should pay attention to the following issues.
1. Clamping of the end mill
If water-insoluble cutting oil is used during cutting, a layer of misty oil film will be attached to the inner hole of the tool holder. When there is an oil film on both the tool holder and the tool holder, it is difficult for the tool holder to firmly clamp the tool holder. It is easy to loosen and fall. Therefore, before the end mill is installed, the shank of the end mill and the inner hole of the tool holder should be cleaned with cleaning fluid, and then the installation should be carried out after drying.
2. Vibration of the end mill
Due to the tiny gap between the end mill and the tool holder, the tool may vibrate during the machining process. Vibration will cause uneven cutting of the circumferential edge of the end mill, and the cutting and spreading amount will be larger than the original value, which will affect the machining accuracy and tool life. If the processing system resonates, it may be caused by factors such as excessive cutting speed, low feed rate, insufficient tool system rigidity, insufficient workpiece clamping force, workpiece shape or workpiece clamping method, etc. At this time, adjustments should be taken to cut Measures such as increasing the rigidity of the tool system and increasing the feed rate.
3. End cutting of end mills
In the numerical control milling of the cavity of a workpiece such as a mold, when the cut point is a concave part or a deep cavity, the extension of the end mill needs to be lengthened. If a long-edged end mill is used, due to the large deflection of the tool, it is easy to produce vibration and cause the tool to break. When using a large-diameter end mill on a horizontal CNC machine tool to process a workpiece, the deformation caused by the weight of the tool is relatively large, and more attention should be paid to the problems that are prone to edge cutting. In the case of a long-edged end mill must be used, the cutting speed and feed rate must be greatly reduced. Drilling and milling machine fixture
4. Selection of cutting parameters
Cutting speed and feed rate should be adjusted appropriately according to the actual situation. When the tool life is the priority factor, the cutting speed and feed speed can be appropriately reduced; when the chip leaving the edge condition is not good, the cutting speed can be appropriately increased.
5. Selection of cutting method
Climbing milling helps prevent damage to the cutting edge and can increase tool life. But there are two points to pay attention to: If you use ordinary machine tools to process, you should try to eliminate the gap of the feed mechanism; ②When the surface of the workpiece is left with the oxide film or other hardened layer formed by the casting and forging process, it is advisable to use up milling.
6. The use of cemented carbide end mills
The application range and application requirements of high-speed steel end mills are relatively wide. Even if the cutting conditions are slightly improperly selected, there will be no major problems.
Second, the fault diagnosis method of CNC milling machine:
Intuitive method: Intuitive method is a method of diagnosing faults through changes in appearance, sound, color, smell, etc. It has the following methods.
Check carefully with your eyes for problems such as blown fuse, burned device and open circuit, and observe whether the drive shaft of the mechanical part is bent or shaken.
3. Preparation before work of CNC drilling and milling machine:
The CNC drilling and milling machine needs to be strictly prepared before operation, so that it can work better. The preparation before work is as follows:
1. Before operation, you must be familiar with the general performance, structure, transmission principle and control program of the CNC drilling and milling machine, and master the functions and operating procedures of the operating buttons and indicator lights. Do not operate and adjust the machine tool until you understand the entire operation process.
2. Before starting the machine tool, check whether the electrical control system of the machine tool is normal and whether the lubrication system is normal or not.
3. After the program is debugged, it must be approved by the instructor to operate according to the steps, and it is not allowed to skip the steps.
4. Before machining parts, it is necessary to strictly check whether the machine origin and tool data are normal, and perform a simulation run without cutting trajectory.