CNC machining technology is based on traditional machining technology, through effective combination with computer numerical control technology, computer-aided design and auxiliary manufacturing technology, thus forming CNC machining technology. Compared with traditional processing technology, CNC processing technology has greater advantages and has become an indispensable important processing technology in the contemporary mechanical processing industry. The difference between CNC machining and traditional machining technology is elaborated in detail from the aspects of machining technology, fixtures, tools, machining methods, cutting parameters and thermal deformation.
Keywords: CNC machining technology; traditional machining process; fixture; cutting tool; cutting parameters; thermal deformation
On the basis of traditional processing technology, combined with various advanced technologies, major breakthroughs have been made in key technologies, forming a CNC processing technology. At present, CNC machining technology has also become the main development direction of the modern machining industry. In China’s processing industry, because the processing methods of ordinary machine tools are relatively mature in technology and methods, it not only continues the current ordinary hangar processing methods of CNC lathes and CNC milling machining centers, but also effectively absorbs the ordinary machine tools. Mature technology and processing methods fully combine the mature technology of ordinary machine tools with the processing characteristics of CNC machine tools, thereby effectively exerting the performance advantages of data machine tools. In the application process of current CNC machining methods, it also brings new technical problems, so it is necessary to effectively analyze the difference between data processing and traditional processing technology, so as to effectively play the advantages of CNC machining and ordinary machine tool processing.
1 Processing technology
In the ordinary machining process, whether it is positioning reference, clamping method, tool, cutting method, etc. can be simplified, but the data processing process is more complicated and needs to be fully considered. In addition, even if the same machining tasks are the same, the CNC machining process can have multiple solutions, and multiple machining parts and tools can be arranged as the main line in the process. The process has diverse characteristics, which is the most obvious difference between the CNC machining process and the traditional machining process.
2 Clamping and clamping
In the CNC machining process, not only to ensure that the coordinate direction of the fixture and the machine tool is relatively fixed, but also to coordinate the dimensional relationship between the parts and the machine tool coordinate system. In addition, the positioning and clamping steps need to be effectively controlled during the clamping process. In addition, under the traditional processing technology, due to the limited processing capacity of the machine tool itself, multiple clampings are required during the processing. In addition, special fixtures need to be used, which leads to higher fixture design and manufacturing costs, and actually increases the production cost of the product. However, the positioning of the CNC machining process can be debugged by instruments. In most cases, it is not necessary to design special fixtures, so the cost is relatively low.
During the processing of 3 kinds of tools, the choice of tools needs to be determined according to different processing techniques and methods. Especially in CNC machining, the use of high-speed cutting is not only beneficial to improve the processing efficiency, but also can guarantee the processing quality, effectively reduce the probability of cutting deformation, shorten the processing cycle, so the demand for tools under high-speed cutting further increases. At present, there is also a dry cutting method, that is, no cutting fluid is added or only a small amount of cutting fluid is used for cutting, so the tool must have good heat resistance. Compared with ordinary processing technology, CNC processing technology has higher requirements on the performance of cutting tools. Since the current CNC machining technology has become the main technology in the modern machining industry, this has also led to huge changes in the tool industry. It is no longer simply used to produce and supply cutting tools, but has begun to transform new cutting processes and related supporting technologies into product development. Tool manufacturers have also become important partners in the current machining industry to improve production efficiency and quality and reduce production costs.
4 processing methods
In the traditional processing process, some processing processes cannot be precisely controlled, so it is not easy to use. However, when machining with CNC machine tools, these carefully used addition methods become feasible. In addition, in the process of CNC machining, circular interpolation, post-processing and CNC trimming methods have replaced the filling method, empty tool method and trimming method in the traditional hole positioning processing. In addition, the hard cutting process has also begun to be used in processing, not only effectively ensuring the improvement of processing efficiency, but also greatly reducing processing costs and equipment investment. At the same time, compared with wet cutting, dry cutting can be said to be a green manufacturing process, with obvious cutting advantages. However, due to its large cutting force, there are problems of deformation and tool wear during the cutting process.
5 cutting parameters
In the traditional machining process, in the process of operating the machine tool, workers often rely on their own practical experience and technical experience to operate. From the perspective of human control ability and safety, it is generally more conservative, especially for complex curves and curved surfaces, workers are prone to errors during operation. In order to reduce the scrap rate, the choice of cutting parameters is always very cautious. CNC machine tools use a control system to control the movement of the machine tool. Regardless of the shape of the surface, the machining process can be conveniently controlled by the program. The movement path of the tool on the workpiece is fully automatic, flexible and uninterrupted. The most reasonable cutting amount can be set in the processing program, which will not cause waste and unnecessary loss of materials, and maximize the processing efficiency. This is unmatched by ordinary machine tools.
6 Thermal deformation
Whether in traditional machining or CNC machining, thermal deformation will inevitably occur during cutting. However, in the finishing stage, thermal deformation will directly affect the accuracy of the final workpiece. In the traditional processing process, due to the longer buffer time between the various processes, it is possible to clearly divide the various processing stages. Therefore, after the temperature rise generated in the previous processing process is restored, the finishing process stage can be started. It can be specifically divided into several working steps, which can effectively reduce the adverse effects caused by thermal deformation. However, the CNC machining process requires continuous addition of multiple surfaces and has high efficiency, which results in no time for heat transfer during the cutting process. Therefore, thermal deformation is a prominent problem in the CNC machining process. At present, in the machining process of CNC machine tools, cutting fluid is usually used to reduce the temperature and chip breaking, so as to ensure trouble-free production.
CNC machining technology is developed on the basis of traditional machining technology. Data processing technology is formed through effective combination with computer technology. Therefore, traditional processing technology is regarded as the technical guarantee and source of CNC processing technology. Through the comparative analysis of the two, the advantages and disadvantages of each can be clarified, so as to better ensure the scientific and reasonable processing program in the processing process and promote the healthy and orderly development of the processing industry.