China's domestic CNC machine tools break through the monopoly pattern of foreign machine tools

Recently, Tsinghua University and Nanjing Sikai Electronic Enterprise Co., Ltd. jointly developed a five-axis linkage laser processing machine tool to successfully overcome this problem: put a metal molybdenum sphere into the processing head of the machine tool, just 5 minutes, a delicate spherical surface The grid is formed.

“It has a processing accuracy of μ, which is equivalent to 1/70 of the hair. Its biggest highlight is the five-axis linkage CNC and fiber laser.” According to the company's technicians, this machine with a cash register size can also process Medical devices such as cardiac stents with extremely high precision requirements can be used in aerospace, medical and other fields.

In the development of high-precision radar, a core micro-device is needed - a spherical grid made of metal molybdenum with a diameter of only 12 mm, and 72 trapezoidal grids in the grid. The "ribs" connected between the small grids are only 0.12. Millimeter.

Don't underestimate this insignificant 12mm. Since the melting point of molybdenum is as high as 2000 °C, there is no processing equipment in China, and the foreign technology is blocked. The spherical grid processing technology has become a bottleneck restricting the improvement of high-end products in China.

Machine tools are the foundation of manufacturing, and CNC systems are more called "brains" in machine tools. It represents the level of industrial development of a country and is also the embodiment of the country's comprehensive strength. The development of CNC machine tools in China has experienced 30 years of ups and downs, has entered the mature period from the growth period, and has repeatedly innovated in the high-end field, constantly breaking through the monopoly of foreign countries.

Develop your own "brains"

At present, China has become the world's largest machine tool consumer and CNC machine tool importing country, and CNC system is an important part of CNC machine tools, its cost accounts for 30% to 50% of the total machine tool cost.

Statistics show that about 70% of the domestic high-end CNC system is occupied by overseas CNC companies, and some high-end CNC machine tools are still regarded as strategic materials in the international market subject to embargo restrictions. The five-axis (coordinate) linkage CNC machine tool is one of the high-point markings of CNC machine tool technology. The five-axis linkage milling machine for large-scale propeller space surface machining has caused a sensational US and Japanese sanctions against the former Toshiba incident of the Soviet Union; 10 years ago The US Congress also imported the so-called "Cox Report" for so-called sanctions because it imported 16 sets of such multi-axis old machine tools for aircraft manufacturing. (Note: On May 25, 1999, the US House of Representatives was a Republican The investigation committee led by Cox published an investigation report that smeared China's self-reliant and independent development of cutting-edge technology and major science and technology related to the development of the national economy as "stealing" or illegally "acquiring" from the United States.

According to industry insiders, in this major technical equipment with completely independent intellectual property rights, Wuzhong Group has achieved three major technological breakthroughs: First, the equipment's ultra-heavy-duty high-precision headstock has a large weight, high strength and rigidity requirements. It has reached the limit of the current world headstock manufacturing; secondly, the research and precision of the ultra-long bed manufacturing process has reached the domestic leading level. The length of the machine bed is 45 meters, the error of the guide rail reaches any length of 1 meter is less than 0.015 mm, the error within any length of 20 meters is less than 0.16 mm, and the error within 45 meters of the length is not more than 0.27 mm. The third is the first domestic double working group. Three-channel CNC technology and three-axis synchronization technology.

"Compared with developed countries, we are accelerating to catch up. Some products have been successfully developed and even panicked by foreign counterparts, which not only broke their long-term monopoly in the domestic market, but also forced them to lower the price of their products." Yu Chengting, executive vice president of the Tool Industry Association, said.

Grasping the gap
Although domestic high-end CNC machine tools have made major breakthroughs in many fields, in the opinion of industry experts, there is still a big gap between China's CNC machine tool technology and the world's advanced level.

The first is that the accuracy is generally not enough. Only a few products have achieved European standard positioning accuracy. The accuracy gap is only a superficial phenomenon. Its essence is the reflection of the gap in basic technology. For example, finite element analysis is generally not performed, and no stiffness test is performed; most of them do not use positioning accuracy software compensation technology, temperature deformation compensation technology, and dynamic balance technology of high-speed spindle system;

Secondly, the gap in the development of basic materials has not spread the high-strength densely-cast cast iron. In Europe and America, a number of advanced products have been made of polymer concrete, but China is still blank;

Thirdly, the gap between the high-motion and static-stiffness mainframe structure and the performance development of the whole machine, the design direction of the high-speed machine tool mainframe structure is to enhance the rigidity and reduce the weight of the moving parts. For example, the internationally adopted gantry type, frame type, O-type overall structure, box-box Structure, L-shaped bed, three-axis moving out of the fuselage, side-hung box horizontal machining center.

Most of us are not developed; another important gap is the application technology gap. For example, remote service technology that has begun to spread in foreign countries, we have yet to develop; turnkey project - from machine tool selection, process equipment (knives, clamps, attachments, inspection tools) configuration and provision to the determination of cutting amount, still to be developed; High-speed machine tools are generally not able to do hard cutting, dry cutting performance, high-speed cutting mechanism and cutting database research in China almost blank; can not provide high-speed cutting software packages and so on. The key components, especially the emerging components such as electric spindle, high-speed ball screw pair, linear motor, high-speed high-precision digital CNC system, high-precision high-frequency sound position detection system and so on.

Lu Qijian, general manager of Nanjing Sikai Electronic Enterprise Co., Ltd. told reporters that the five-axis linkage CNC of the machine tool control part is the most difficult and widely used technology in numerical control technology. It is mainly used for efficient, precise and automated machining of complex surfaces.

In June and July of this year, the Industry Development and Reform Commission Industry Department commissioned the China Machine Tool Industry Association to organize 30 industry experts to conduct special research on 61 enterprises and institutes in the aviation, shipbuilding, automobile, power generation equipment and machine tool industries. "By investigating the manufacturing process and equipment of the main key components of aircraft and aerospace engines, we believe that the aviation industry is complex in process, and the required machine tools are high-precision machine tools such as five-axis linkage." According to the China Machine Tool Industry Association, The engine processing uses a large number of high-precision machine tools. The machining requires multi-function, high-precision CNC machine tools, such as CNC vertical lathes, CNC precision boring machines and five-axis machining centers. The CNC system must have advanced programming functions.

"China's CNC companies have the confidence and ability to break the monopoly and technical barriers of foreign companies, use the Chinese 'brains' we developed to equip our country's equipment and break through foreign blockades," said the head of Wuhan Huazhong CNC Co., Ltd. Huazhong CNC took the technical route of the general industrial microcomputer as the hardware platform, and realized the breakthrough of the numerical control system technology through the innovation of software technology. With the use of general industrial computers and electronic devices, the company has independently developed a 4-channel, 9-axis linkage "Huazhong 1" high-performance CNC system that has broken the foreign blockade, reaching the international advanced level.

The tentacles continue to extend
Not only that, China's CNC machine tool products have been extended to complete sets and composite areas: Zhongjie Machine Tool Plant has delivered 4 production lines with CNC boring and milling machine as the main part of the Shanghai Maglev Train Project according to the 7-month delivery date, which is the embodiment of China's machine tool industry. An outstanding representative of the ability to provide complete equipment.

CNC super heavy-duty machine tools are key equipment for major equipment manufacturing and heavy weapons manufacturing in water, fire, nuclear power plant equipment manufacturing, shipbuilding, metallurgical mining, etc. China has become one of the few suppliers of super heavy-duty machine tools. The DL250 5-meter CNC super-heavy horizontal boring lathe is a new product independently developed and manufactured by Wuzhong Group. It is the world's largest ultra-heavy-duty CNC horizontal lathe. The total weight of the machine is up to 1,450 tons. 177 tons, the spindle end face bounce and radial runout are within 0.008 mm.