How to make China's high-end CNC machine tools have their own technical discourse?

The “General R&D of Rolling Function Components of High-end CNC Machine Tools” project is a national science and technology major project led by Professor Feng Hutian of the School of Mechanical Engineering of Nanjing University of Science and Technology. It has now successfully passed the project acceptance of the expert group.

"For the first time in the domestic industry, the accelerated failure time model, test and evaluation method for the rolling function part A+A is proposed, which solves the technical problems of failure-free functional reliability test evaluation and long test time of rolling functional parts."

"For the first time, a total of six volumes of the "Optimized Design Selection Guide for Numerically-Controlled Machine Tool Components" are focused on the demonstration of special results, corporate and user docking demonstrations, and the development needs at home and abroad, and provide detailed and accurate information for CNC machine tools. Operational basis."

"For the first time, we have carried out the static stiffness evaluation of the products of the rolling functional components of key enterprises compared with overseas products, and have taken the lead in publishing the industry assessment report in the country."

One by one “first”, people can not help but wait for the national science and technology major project “common technical research and development of high-end CNC machine tools” led by Professor Feng Hutian of the School of Mechanical Engineering of Nanjing University of Science and Technology.

Fight for technical discourse power

“CNC machine tools are an important manufacturing method for various weaponry and equipment, and also an important guarantee for the modernization of national defense and military equipment. Its level, variety, and production capacity are a manifestation of a country’s overall national strength in technology and economy.” Feng Hutian’s phrase It is pointed out that at present, China's CNC machine tools manufacturing is still mainly based on low-end products, and high-end CNC machine tools and other major equipment still rely on imports.

how so?

The ball screw is the most commonly used precision transmission component on CNC machine tools. Its main function is to convert rotational motion into linear motion, or to convert torque into axial repetitive force, which directly determines the machining accuracy and accuracy of the machine tool. Sexuality and maintainability are key to the key functional components of CNC machine tools.

"If the key areas of technology are subject to long-term constraints, China's rapid growth in equipment manufacturing capabilities and capabilities can only be an empty phrase." Feng Hutian decided to focus his research on rolling common functional components.

In order to thoroughly solve the technical shortcomings of rolling functional components that restrict the localization of high-end equipment manufacturing, it is necessary to comprehensively understand and master the trend of the mainstream technology of foreign rolling functional components, and at the same time, lay a solid foundation for research and solidify relevant basic theories. The series has forward-looking and cutting-edge research.

Feng Hutian’s research team has a long way to go.

One level of improvement shows great strength

According to industry-related data, the localization rate of rolling-function components such as ball screws and rolling linear guides in domestic high-end CNC machine tools is less than 5%, while the localization rate of rolling function components used in mid-range CNC machine tools is only 30%. Feng Hutian analysis pointed out that "the reasons for this situation are many, but there are many deficiencies in the high rigidity design of domestically-made rolling functional parts, the optimization of the precision preloading mechanism of ball screws, and related processing technologies. Important factor."

In view of the current technological and technological bottlenecks in the development of high-end numerically-controlled machine tools in China, the research team has successively tackled problems in terms of precision, friction and wear, fatigue, rigidity, material selection, and reliability test methods for rolling elements.

During the course of the study, it is particularly worth mentioning that the research team has made great breakthroughs in the basic theory and key technologies of the precision forming of heavy thread screw heavy-duty cyclone milling, and realized a large-scale screw hard cyclone milling process and equipment. Comprehensive optimization of overall performance. More importantly, they also improved the accuracy of the processed ball screw pair by one grade. But do not underestimate this level of promotion, it greatly enhances the precision of CNC machine tools in China, which greatly enhance the competitiveness of China's CNC machine tools in the international competition.

However, research on mechanical transmission cannot be separated from a large number of accurate and accurate data verifications. To obtain accurate data, accurate and sensitive detection equipment is indispensable. However, due to the weak foundation of China's research in the field of rolling functional components, many important equipment in the domestic market is almost a blank, let alone purchase.

Without a standardized operating procedure, one has to explore the “darkness” in his own right. No related testing equipment is designed and manufactured on his own drawings. The hardships in this period were only in the heart of their own scientific research. “But no matter how difficult the difficulties are and no matter how many failures we have experienced, we never thought of giving up.” Feng Hutian said that based on the reference and drawing on a large amount of foreign technical literature, they are gradually measuring the rigidity, comprehensive performance testing, and modeling. The testing and other aspects have successfully designed and developed tests and testing equipment such as the screw rigid test stand, the guide Rigid Rigidity Test Bench, and the ball raceway profile error tester, which fill the gaps in related domestic fields.

According to statistics, the research team independently researched and developed 28 sets of testing equipment throughout the country’s major special projects, not only providing testing services in the laboratory, but also directly providing enterprises with multiple sets of test equipment, and has started to The aerospace and electronics industries provide services. The technical performance of some testing equipment has also reached the international advanced level. In addition, they also designed and built friction and wear testing machines, rolling contact fatigue testing machines, screw cooling lubricating test stands, precision materials and analysis equipment, which can provide test bench products, test and detection software and hardware for the industry, and serve manufacturers. And host users.

Extract high-end equipment manufacturing "Pearl"

In the ten years of “fighting against war”, the research team finally succeeded in taking the "Pearl" of China's high-end equipment manufacturing crown, and established a functional reliability, precision retention, life reliability test and evaluation system for functional components. Three "first-time" breakthroughs were achieved, which helped the transformation of China's domestic equipment from "Made in China" to "Created in China."

After listening to reports on related achievements and conducting on-site inspections, the experts of the key laboratory of the Department of Common Technologies and Informatization of the CNC Machine Tool Functional Parts gave a high degree of achievement to the project and a common technology research platform built in the industry. The evaluation also unanimously recommended that “the results should be radiated to more enterprises as soon as possible and a more extensive testing and technical service platform be established as soon as possible”.

Indeed, the study was done well and the application had the final say. Hanjiang Machine Tools and Nanjing Crafts, the leading companies involved in R&D, could not wait to experience the new technology products that the research group has successively launched, and commented: “Product indicators have indeed reached the international advanced level.”

In addition, the high-end products of the rolling function developed by the research group also set up three demonstration application bases for Shenyang high-grade CNC machine tools, Dalian Machine Tool and Baoji Machine Tool. The products are matched with the precision horizontal machining center of Ningjiang Machine Tool Co., Ltd. and domestic rolling is realized. The functional parts in small batches are used for high-end CNC machine tools and have successfully replaced imports.

Since then, China's high-end CNC machine tool industry has completely freed itself from foreign monopoly in technology and technology, and has its own technical voice.

But this does not mean that their mission in this area of ​​research is over. At present, the research group is actively preparing for the establishment of a national-level quality supervision and testing center for domestic CNC machine tools, providing the most authoritative technical services for the domestic industry.