1.4.2 Development of CNC machine tools in China
Numerical control machine tool is a kind of product with high electromechanical integration. It introduces digital control on the basis of traditional machine tool, which changes the operation based on workers’ experience into digital and reproducible automatic operation. It has good processing flexibility, high processing accuracy, high productivity, reduces the labor intensity of operators, improves labor conditions, and is conducive to the modernization of production management and the improvement of economic benefits. The characteristics and application scope of CNC machine tools make them important equipment for the development of national economy and national defense construction. At present, the CNC proportion of the machine tool industry in developed countries is usually more than 60%, and more than 85% in Japan and Germany.
China’s real industrialization process began in the 1950s. For various reasons, we missed the great development period of new industrialization in the 1970s and 1980s, resulting in the machinery and equipment manufacturing industry in China still catching up with and surpassing the developed countries. Since the end of the 20th century, China began to introduce western technology on a large scale. At the same time, we absorbed, merged and created on the basis of the introduced technology, and finally developed our own CNC machine tool manufacturing industry. During this period, China’s overall manufacturing industry began to gradually move from a manufacturing power to a manufacturing power, and the machine tool manufacturing industry also achieved rapid growth of CNC machine tools. The development and innovation of machine tools can reflect the main trend of machining technology to a certain extent. In recent years, China’s joint ventures and cooperation with foreign countries in the CNC machine tool and machine tool industry have been further strengthened, and considerable achievements have been made in terms of accuracy, speed, performance and intelligence.
At present, CNC machine tools produced in China can be roughly divided into three types: economic machine tools, popular machine tools and high-end machine tools. The open-loop control technology is basically adopted for economical machine tools; The popular machine tool adopts semi closed loop control technology, and the resolution can reach 1μm; Table 1-8 describes in detail the use status of machine tools of different grades in China.
Table 1-8 use status of machine tools of different grades in China
|Serial number||Grade of machine tool||Usage status|
|1||Economical machine tool||Economical NC machine tool refers to the NC machine tool with targeted processing function but low function level and low price. It is mainly composed of mechanical and electrical control. Domestic economic CNC machine tools have been well applied in domestic machine tool manufacturers. Economic CNC machine tools are basically domestic products, which can meet the needs of most machine tool users in terms of quality and reliability|
|2||Universal machine tool||About 60% ~ 70% of domestic popular CNC machine tools are domestic products. However, it should be pointed out that about 80% of the CNC systems of these domestic CNC machine tools use foreign products, and domestic machine tool enterprises assemble the subsystems after importing them to form the final finished machine tools. Some of China’s mid-range popular CNC machine tools have strong market competitiveness in terms of function, performance and reliability|
|3||Medium and high grade machine tools||1.The high-grade machine tool adopts closed-loop control and realizes the whole process of unmanned control by computer program. It has various compensation functions, new control functions and automatic diagnosis. The resolution can reach 0.1 μm。
2.In terms of high-end products such as medium and high-end CNC machine tools such as four axis and five axis linkage machine tools, there is still a big gap between domestic products and foreign products. In terms of high-end machine tools, domestic products only account for about 10%, and most of them are imported. The core technology of CNC machine tools, the CNC system, is composed of display, servo controller, servo motor, various switches and sensors. In China, almost all of them need to be imported from abroad. At present, most of the CNC machine tool factories built in the developed coastal areas in China are foreign manufacturers, and most of the core technologies are mastered by foreign parties. Medium and high-end CNC machine tools that can be made in China are mostly in the assembly and manufacturing process, and generally do not master the core technology.