China needs to vigorously develop ultra-precision CNC machine tools

“The R&D and manufacturing technology of ultra-precision machine tools is a cutting-edge technology that will lead the machine tool's machining accuracy to continue to move further into the technical fields that humans have never covered.” Liu Bingye, director of the Beijing Machine Tool Research Institute, recently held the China Machine Tool 2014 The development of high-end forums pointed out that "ultra-precision machine tools are the tools that developed countries attach great importance to and take measures to control, and it embodies the competitiveness of a national precision technology."

Liu Bingye emphasized that in the past 30 years, the world-wide machine tool technology has developed to a great extent, and the development trend of machine tool technology has also exhibited diversified features, but high-precision is the mainstream development trend of CNC machine tools, and ultra-precision The precision of machining is more than an order of magnitude higher than that of precision machining.

In fact, the technical field involved in ultra-precision machining technology is very rich. In the course of more than 30 years of research in the Beijing Institute of Machine Tools, Liu Bingye systematically summed up 36 key frontier studies and 11 leading core technologies for the related technologies involved in ultra-precision machining technologies. Among them, the key frontier research includes six aspects of design, moving parts, measurement analysis, process technology, host manufacturing technology and machine tool application condition technology. Leading core technologies include: manufacturing technologies for key structures of precision ultra-precision spindles, manufacturing technologies for key structures of precision and ultra-precision linear motion components, high-resolution motion-driven technologies, machining process manufacturing techniques for key machine parts of machines, and feature technologies for components to withstand external disturbances The structure and manufacturing technology of high-stability and rapid linear motion, the nested structure design technology of multi-axis machine tools, and the integrated manufacturing technology of machine tools for target parts manufacturing.

"There are three key technologies that cannot be avoided in the development process of machine tools from micron to nanometer precision. These three technologies are also the research threshold for nano-precision machine tools." Liu Bingye said that one of the technologies is a bearing technology without hysteresis. Hysteresis phenomenon exists in a large number in mechanical systems. Hysteresis not only seriously affects the accuracy of the positioning accuracy and repeatability of the machine slides, but also affects the high resolution of the movements. It also affects the precision and surface roughness of precision parts. . The hydrostatic bearing technology can solve the phenomenon of mechanical hysteresis well, and can homogenize the geometric error, and get a lot of applications in ultra-precision machine tools. Hydrostatic technology has made significant progress in the past decade, and self-compensation feedback technology has become more mature. The flow control throttling technology has greatly improved the stiffness of hydrostatic bearings, and the hardness of materials processed by ultra-precision machine tools has been continuously improved.

The other two key technologies are high-resolution drive technology and micro-vibration processing technology in mechanical systems. Nano-scale resolution is a feature of ultra-precision machine tool performance in the past decade or so. There are many factors that influence the motion. At the same time, a large number of experimental studies have found that vibration signals of the order of 10 nanometers are present in many mechanical actuators and cause disturbances in the execution and determination of mechanical sensitivities. Such vibrations are called microvibrations. "In-depth research on the mechanism of micro-vibration and the search for solutions are the only way for ultra-precision machine tools to reach nano-precision," said Liu Bing-ye.