China CNC milling machine development trend

my country's CNC milling machine has made great progress in terms of product type, technical level, quality and output, and has also made major breakthroughs in some key technologies. According to statistics, there are currently 1500 kinds of CNC machine tools available in the market in my country, covering almost the entire variety of metal cutting machine tools and the main forging machinery. It has a wide field and can keep pace with Japan, Germany and the United States. This indicates that the domestic CNC machine tool has entered a period of rapid development.

　　The development trend of CNC milling machine is relatively slow

　　 In recent years, my country's machine tool industry has continuously undertaken the task of providing high-level CNC equipment for national key projects and national defense military construction. For example, the domestic XNZD2415 CNC gantry hybrid machine tool fully absorbs the advantages of the flexible configuration and diversity of the parallel machine tool and the large processing range of the traditional machine tool. The basic gantry is formed by a two-degree-of-freedom parallelogram parallel mechanism, and a two-degree of freedom series structure is added to the parallel platform The A and C axis swing angle milling heads, combined with the longitudinal movement of the table, can complete five degrees of freedom. This configuration is the first in the world. The NC system developed based on RT-Linux has real-time and reliability, can be connected with multiple PLCs in the same network, can control the five-axis linkage of the machine tool, and realize human-machine dialogue. The working space of the machine tool is 4.5mx1.6mx1.2m, the A-axis rotation angle is ±1050, the C-axis continuous rotation angle is 0-4000, the spindle speed (stepless) is up to 10000r/min, and the repeated positioning accuracy is ±0.01mm. Five-axis linkage high-speed cutting of hydraulic turbine blades and guide vanes.

　　The development of my country's machine tool industry has already had a relatively sound industry foundation. The development time of CNC milling machines in my country is relatively short, and the start is much behind that of developed countries. As an indispensable important equipment for modern industrial production, CNC machine tools have become an important strategic equipment of the country, and its technical level can reflect the comprehensive national strength of a country. In the past, when our country could not produce CNC machine tools independently, it imported products from abroad at high prices, but the technology was still in the hands of developed countries. The world's machine tool industry is mainly concentrated in Asia, the European Union, the Americas and other regions, with output value accounting for about 90% of the world. Among them, Japan, Germany and China are the main machine tool producing countries. From the perspective of its own situation, my country's machine tool industry ranks first in the world, but it faces many challenges such as irrational industrial structure and insufficient independent innovation capabilities. In the process of the development of the machine tool industry, China must accelerate to make up for the shortcomings in reality, and under the guidance of clear industrial development goals and development priorities, systematically promote the development of the machine tool industry with a view to achieving The transformation of a production power.

　　The current industrial pattern of CNC machine tools in my country is very obvious. In Zhejiang, Shandong, Beijing, Hebei and Sichuan regions, a relatively complete industrial system has been formed. On the one hand, it is because these regions have a relatively fast economic development rate and a high level of openness, which is conducive to the introduction of foreign advanced technology. On the other hand, because these regions have a wide market, such as Sichuan, the economic level is obviously not as good as that of the east coast. However, in the southwest region, the market for Sichuan CNC machine tools is broad, and with the support of the state, it has developed rapidly.

　　 From the perspective of my country's CNC machine tool industry, the regional characteristics of my country's CNC machine tool development are very obvious. The obvious regionality also reflects the unbalanced development of CNC machine tools in my country. For example, in some old industrial production bases in my country, the development speed of CNC machine tools is relatively slow. It is hoped that with the support of technology and policies, my country's CNC machine tool innovation ability is getting stronger and stronger, and the enterprise's own development is getting better and better.

  Speed and accuracy are two important indicators of CNC machine tools, which are directly related to product quality and grade, product production cycle and competitiveness in the market.

         In terms of processing accuracy, in the past 10 years, the processing accuracy of ordinary grade CNC machine tools has been increased from 10μm to 5μm, and the precision-grade machining centers have been improved from 3~5μm to 1~1.5μm. 0.001μm). The improvement of machining accuracy is not only the use of ball screw pairs, static pressure guides, linear rolling guides, magnetic suspension guides and other components, which improves the control accuracy of the CNC system, the application of high-resolution position detection devices, but also the use of various Error compensation technology, such as screw pitch error compensation, tool error compensation, thermal deformation error compensation, space error comprehensive compensation, etc.

        In terms of processing speed, high-speed processing originated in the early 1990s. It is characterized by the application of electric spindles and linear motors, which greatly improves the spindle speed. The feed speed is more than 60m/min, and the feed acceleration and deceleration reach 1~ Above 2g, the spindle speed is above 100000r/min. High-speed feed requires the CNC system to have a fast calculation speed and a short sampling period. It also requires the CNC system to have sufficient advance path plus (decrease) speed to optimize the preprocessing capability (forward processing). Some systems can process 5000 blocks in advance. In order to ensure the processing speed, the high-end CNC system can change the feed speed from 2000 to 10000 times per second.