CNC machining is a production technology in the field of production and processing, which is relatively complex, strict in operation and exquisite in technology. Under high speed and high feed speed, it can complete various requirements of rough machining and finish machining.
CNC machining is very strict in machine tool performance, tool selection, cutting way, processing technology, parameter design and intelligent programming. Moreover, CNC machining for mold cavity is difficult, time-consuming and requires more attention.
For the NC machining of die cavity, how to improve the quality and efficiency of machining, the author will analyze from the following five aspects.
1. Performance of CNC machine tools
Machine tool is the most basic operating part of NC machining, and it is the working platform supporting a series of NC machining processes. The performance of machine tool is directly related to the quality of NC machining. Efficient NC machining often depends on good performance CNC machine tools to implement. To ensure that the performance of CNC machine tools can meet the needs of efficient CNC machining, the following should be done:
One is to observe whether the physical structure of the machine tool, that is, accuracy and rigidity meet the standards. Because the raw material itself has high hardness, it needs to use milling cutter with a certain elongation to process mold cavity, which requires the anti-seismic ability and machining accuracy of the machine tool to meet the standard requirements. Therefore, high rigidity and high accuracy are the most basic requirements for efficient CNC machining machine tools;
Second, the speed and power of the machine tool must be high, so that the speed of the spindle associated with the tool can be fast enough. At the same time, the coordinated operation of the cavity and other parts needs to be completed to ensure the consistency and tightness of the machining;
Thirdly, the machine tool should have the ability of multi axis linkage and deep cavity comprehensive cutting. Multi axis linkage can support the continuous rotary feed of the machine tool table. The deep cavity with complex structure needs multi axis linkage to process various curved mold parts;
Fourth, the control system of machine tools must be advanced. The control system of CNC machine tools in China has been continuously upgraded and improved. At present, it has the functions of self-adjusting cutting feed speed, thermal deformation compensation of machine tools and high-speed transmission of CNC machining data.
2. Tool system
The efficient NC machining of die cavity also needs to be improved in the aspect of tool system. The following factors need to be considered in the selection of machining tools:
First of all, high rigidity and wear-resistant tool material should be selected to ensure that it is not easy to deform or damage during machining, so as to effectively avoid knife edge damage or other tool failure in high-speed machining, so as to avoid reducing machining efficiency and surface quality problems of processed products. At the same time, in the tool system management, it is necessary to set the relevant cutting parameters of the tool system to ensure the high accuracy of machining;
Secondly, in the connection of different cutting edges, it is better to use the chamfering tool tip to avoid damaging the tool due to excessive thermal friction. At the same time, in the actual operation, it is necessary to select different types and shapes of machining tools according to the specific situation, so as to improve the machining accuracy and efficiency according to different machining requirements. At the same time, in the actual machining, it should be noted that the tool used must be consistent with the tool parameters selected by the programming, so as to prevent the machining accuracy of the die from being affected by the error;
Thirdly, high-precision blade and dense tooth cutter should be selected. In this way, the performance of high-speed machining can be exerted and the efficiency of material cutting can be improved;
Finally, the automatic tool change system should be adopted. This is to automatically change the tool to compress the time and improve the positioning accuracy.
3. Cutting mode
How to cut is an important index to test the level of NC machining, and also an important embodiment to test the professional ability of NC programmers. Because the cutting is directly related to the efficiency and quality of NC machining, NC programmers must choose a reasonable way according to the actual situation of NC machining. If the cutting way is not selected properly, the time and progress of NC machining will be delayed, and the machining quality may also be affected. Therefore, NC programmers often need to go through precise thinking and calculation to determine the best way to cut, save time, ensure quality and improve efficiency as much as possible.
At present, most of the CNC programming tool cutting methods in our country use CAM software. For the rough machining of mold cavity, most of the time is spent in the rough machining of complex parts. Because there are many methods to generate tool path, the processing time that we choose different tool cutting methods, i.e. the length of tool path, will be very different. For the problem of low machining quality, it is often because of the wrong choice of the cutting way. Therefore, the cutting way is also an important parameter to measure the level of NC machining, which puts forward very high requirements for the relevant NC programming and technical personnel. It is necessary to choose the most reasonable cutting way, and constantly improve the technology, so as to promote the level of NC machining Break up.
4. Processing technology and parameters
Intuitively judging the strength of NC machining ability is largely reflected in the cutting efficiency, that is to say, it is necessary to make an article from the aspects of rotation speed, cutting amount and feed speed, so as to promote the improvement of NC machining ability by improving the cutting efficiency. Therefore, in the process of NC machining, it is necessary to ensure the effective cutting parameters and give full play to the cutting performance of the tool.
In addition, for the optimization of machining parameters, it is necessary to establish an effective instantaneous cutting force model, which requires more technicians
