The application and development of CNC milling machining
Milling is a metal cold machining method; CNC machines can process complex rotary body shapes. To improve a country’s comprehensive national strength and status needs to vigorously develop advanced manufacturing technology with CNC technology as the main core. CNC milling processing is one of the important parts. CNC milling processing is inseparable from the CNC milling machine, the core equipment of CNC milling processing. The main purpose of the CNC machining process design is to set up the machining process flow, which is also an important preparation work before CNC machining. With the development of society and the progress of science and technology, more and more fields need to apply to CNC milling technology. This paper focuses on the big picture, mainly from the main application of CNC milling processing technology and the future development trend of two aspects of the rough discussion; I hope that the future development of the industry to provide reference.
1. CNC milling machine application practice
1.1 The composition and principle of CNC machine tools
The core part of the CNC machine tool is the computer numerical control device, whose main function is to execute the input part machining program or operation command and then transmit the control command to the corresponding execution parts. A computer numerical control device, a CNC device, has a computer system, position control board, communication interface board, PLC interface board, extended function module, and the corresponding control software.
The servo drive unit comprises CNC machine tools, drive, and measurement devices, including spindle servo drive, spindle motor, and feed servo drive. The operation panel allows the operator and the CNC machine tool for information interaction, through which the operator operates the CNC machine tool for programming and debugging; the operator also uses the operation panel to understand the operation of the CNC machine tool window. Control media and program input and output devices are now mainly by the magnetic cartridge and disk drive to play; modern CNC systems usually use communication methods for information exchange; the main ways are serial communication, automatic control of special interfaces, and network technology. PLC consists of hardware and software, and its logic circuit consists of relays, solenoid valves, contactors, travel switches, etc., which collectively accept CNC MST commands, control panels, and the machine side of the control panel and debugging. It accepts I/0 signals from the control panel and the machine side and commands the machine’s working state and action after processing. The body of the machine tool is the control object of the CNC system and is the main part of the execution of machining parts. Its main components include the main moving parts, feed drive parts, support parts, and special devices.
CNC machine tool processing parts in the process are the first such as the spindle speed, loose clamping workpiece, tool feed and retraction, and other operations as well as the relative displacement between the workpiece will produce the corresponding digital code, and then use the NC program, the use of media or manually input to the NC storage unit, the NC device through the processing of these data and arithmetic, to issue a variety of drive instructions to drive the CNC machine tool servo system or other execution elements, so that the CNC machine tool to process all aspects of the requirements of the parts, so that their size and shape are in line with the expected results.
1.2 Classification of CNC machine tools
There are many types of CNC machine tools and different types according to different classification criteria. The control function can be divided into point control CNC machine tools, linear control CNC machine tools, and contour control CNC machine tools. The main difference between these types of CNC machine tools is the number of axes that the tool or table operation difference can control. According to the difference in the type of feed servo system, mainly with or without position measurement, feedback devices can be divided into open-loop CNC machine tools, semi-closed-loop CNC machine tools, and closed-loop CNC machine tools. The classification of processing technology can be divided into CNC machine tools, metal cutting class CNC machine tools, special processing class CNC machine tools, and plate class CNC processing machine tools.
2. CNC milling applications
2.1 CNC milling processing characteristics
CNC milling processing high precision, CNC machine tools are in computer numerical form to give instructions for processing, the pulse equivalent of the current CNC device generally reaches 0.001mm, CNC machine tool processing accuracy than before greatly improved, CNC machine tool processing mode avoids human interference factors, the same batch of parts consistency is very good, stable processing quality, product qualification rate is high. CNC machine tools on the adaptability of the processing object only need re-programming to be achieved in processing new parts. The high degree of automation and low labor intensity is another feature of CNC technology. CNC machine tools for parts processing are pre-programmed; the operator only needs to operate the control panel; the other machine tool action until the operation is completed is automated, which does not require repeated manual operation, labor intensity, and tension are smaller, the labor conditions have been improved accordingly. CNC milling processing of high productivity. CNC machine tool automation reduces manual time-consuming, adjusting the new processing parts when there is almost no need to adjust the machine tool, in addition to processing the high precision of the advantages of all aspects of the production of a significant reduction in the production of time, and effectively improve the production efficiency. In addition, the application of CNC milling is also conducive to the modernization of effective management and to improve the industry’s economic efficiency.
2.2 The scope of application of CNC milling processing
Due to the advantages of CNC machine tools (Figure 1) that other equipment does not have, the application of CNC machining is increasing. However, it can only partially replace ordinary machine tool processing, sometimes needing to consider the most economical way of production, and is still gradually becoming a highly efficient and advanced technology. CNC milling applicable industry scope includes these: multi-product type small batch production parts, complex shape and structure of the parts, high precision requirements and the need for frequent change of parts, high cost and high requirements for the product life of the key parts, short production cycle and the urgent need for parts and components, batch size and high precision requirements of the parts.
In the application of the CNC machining industry, first of all, the aviation industry cannot be separated from the CNC milling processing; aircraft fuselage, wings, tails, and aircraft engine parts processing need CNC milling processing technology, and these rely on high-speed five-axis machining centers, five-axis composite machining centers, five-axis CNC milling machine tools for advanced gear and thread processing CNC milling machine tools. Automobile manufacturing industry on the demand for CNC milling processing is also larger in the automobile manufacturing industry the total proportion of CNC milling machines reaching 40%; the automobile manufacturing industry requires specificity of the parts and components, so they need a large number of high-efficiency, high-performance CNC milling machines tools. The electronic information equipment manufacturing industry also needs CNC milling processing involving specific lathes, such as high-speed milling centers, high-speed machining centers, small fine-type milling machines, and small precision punching machines. CNC milling has gradually come into people’s daily lives; we now use cell phones for key precision parts and CNC milling technology for manufacturing production. More advanced medical equipment needs CNC milling technology in other medical equipment industries, such as CT diagnostic instruments based on vision-guided surgical robots. Military equipment in the automatic targeting control of artillery, radar, and missile automatic tracking control are many CNC technologies in the servo motion control technology.
Figure.1 Numerical Control Machine Tools
2.3 The application of CNC milling in machining technology
The application of CNC milling processing in machining technology is mainly divided into three aspects; the first is the application of CNC milling processing in machining equipment, the process of machining, its basic component is machining equipment, which plays a self-evidently important role in the machining process. The quality of mechanical equipment is also one of the key factors affecting the quality and productivity of machining products. The application of CNC milling technology in machining can effectively reduce the incidence of malfunctioning in the machining process, which in turn can guarantee the smooth progress of the machining process and provide reliable and stable technical support for the machining process. The second is the application of CNC milling processing in machining production; with the development of society and the progress of science and technology, CNC machining technology has become a major trend in industrial development. The basic mode of mechanized production, coupled with the application of CNC technology, effectively breaks through the short board of traditional machining in the design of parts, enhances the stability of machining, and greatly improves the quality of the finished workpiece and production efficiency. Third, CNC milling processing can also be applied in the detection process of parts; in the machining process, detecting processed parts is an effective means to improve the quality of processing and parts accuracy. The use of advanced testing instruments, parts of the cracks, breakage, and other places for high-precision inspection, but also corresponding to the parts of the overall all-round detection, scientific analysis of the entire processing workpiece, and the detection results proposed optimization measures, fully reflecting the advantages of CNC technology in automation and networking, to meet the demand for machining in a variety of industries under the premise of promoting machining in the development of innovative workpieces, but also to accelerate the application and development of CNC milling processing technology in machining technology.
3. The development of CNC milling processing
Since the birth of CNC technology in the middle of the last century, CNC milling machines have greatly changed the manufacturing industry. CNC machining of good flexibility, high productivity, high machining accuracy, and low labor intensity of workers, conducive to the modernization of management and improvement of the economic efficiency of enterprises. The CNC milling machine has also become a key equipment for developing the national economy and defense construction. Since entering this century, China’s economy and international full convergence, CNC milling and CNC milling machine manufacturing are faced with both the further development of the manufacturing industry brought about by the opportunity and the challenges of international trade and the impact of international technology, with the expanded application of CNC milling technology, related technology to develop further to meet the new needs and situation, which will be the future development of the CNC machining industry.
CNC machining high-speed development trend, accompanied by automotive, aviation, aerospace, and defense industries such as high-speed development, aluminum alloys, and other new materials, are highly demanding CNC machining Yu high. Now, the highest spindle speed of a CNC milling machine has reached 200000r/m, a feed rate in the resolution of 0.1μm, a maximum feed rate of 240m/min, and can obtain the accurate processing of complex surfaces. Microprocessor has developed a 32-bit and 64-bit CNC CPU; the frequency has been increased to thousands of megahertz, and the speed of tool change has generally reached about 1s, the fastest advanced foreign 0.5s.
The development of high-precision CNC machining and CNC milling machine precision has exceeded the previous static precision indicators. Now, more and more on movement accuracy, thermal deformation accuracy, and vibration detection put higher requirements. Now, the industry is mainly from improving the CNC system control accuracy and using error compensation technology to improve the high precision index of CNC milling processing technology in two aspects.
CNC milling has become an important part of machining, applied in more and more industries, plays a key role, and provides strong technical support. The future development trend is rapid and huge space for development; the future development trend of high degree of operation and high precision operation also puts forward higher requirements for the industry, which is also the future of the real industry 4.0 action.
Author: Huang Meifang