Since the 20th century, the appearance of transmission gears has fundamentally changed the structure and performance of machine tools. With the emergence of electrical control, hydraulic transmission and other scientific technologies and their widespread application in machine tools, machine tool technology has developed rapidly; In recent years, the development and application of electronic technology, computer technology, information technology and laser technology in machine tools have made machine tools develop rapidly. The rapid development of new technology and the diversity of objective requirements determine that machine tools must be diversified. Therefore, modern machine tools must not only ensure accuracy, efficiency and high automation, but also have certain flexibility, which is flexibility, so that they can easily adapt to changes in processing.
In recent years, CNC machine tools have been paid more and more attention for their high precision, high productivity and high flexibility to adapt to small and medium-sized batch production. As a CNC machine tool that needs manual operation, the cycle is completed by a CNC machining program, which is convenient to adjust and adapts to the flexibility of products, making it possible for small and medium-sized automatic batch production.
CNC machine tool technology has also changed the structure of weight. The main transmission system is adjusted by DC or AC motor, and the spindle realizes stepless speed regulation and simplifies the transmission chain. Using AC frequency conversion technology, the speed range can reach more than 1: 10, and the spindle speed can reach 75000 rpm. The feed system of machine tool is usually realized by ball screw driven by AC servo motor to simplify the structure. In order to improve work efficiency, the current fast-forward speed can reach 60m/min. The cutting feed rate has reached 6 ~ 10m/ min. The ultra-precision CNC lathe developed in Japan has a resolution of 0.065438±0um and a roundness error of 0.03um. At present, the positioning accuracy of the machine tool machining center can reach 65438±0.5um, and the control accuracy of the numerical control turntable is one ten thousandth of a degree. In recent years, the reliability of CNC machine tools has been continuously improved, and the average time between failures of CNC devices has reached 10000 hours. This shows that numerical control technology has developed rapidly. Applying CNC machine tools to improve the skill level of machinery manufacturing industry.
The gap between skill level and performance is also obvious. Foreign countries can achieve the resolution of 15- 19 axis at 0.1-0.0/um, while China can only achieve the resolution of 5-6 axis at 1um. The quality, reliability and stability of CNC machine tools are not enough, especially the development of advanced CNC systems needs further efforts. The basic theory and application of machine tool technology have obviously failed, and the technical quality of employees can't keep up with the needs of the rapid development of modern machine tool technology.
The demand for CNC machine tools in China is increasing, so the machine tool enterprises in China must strive to expand the technical team, improve the technical quality, learn and introduce foreign advanced science and technology, so as to drive the world advanced level as soon as possible.
Keywords: CAD/CAM technology, development trend, equipment manufacturing, spindle and triaxial machine tools, CNC machining technology, CNC machining center milling machine.