China's Efficient Precision Stamping Dies Reach International Advanced Level

Since it was invented in Europe in the 1920s, fine scouring technology has gone through more than 90 years. It is one of the most important precision plastic forming methods in the field of heavy plate manufacturing. It is economically producing high-volume, high-quality, versatile black metal. High-tech and economical methods for non-ferrous metal parts. The fine stamping press completes a stamping process. Through the processing of special fine stamping dies, one or more high precision parts that can be directly used for assembly are manufactured. They have been widely used in electronics, computers, electric power, and home appliances. , automotive and aerospace. According to Luo Baihui, head of the International Die & Mould and Plastics Industry Suppliers Association, 40 countries around the world currently use precision punching technology. There are about 4500 precision punching machines and about 10,000 production parts. For example, a car (car) includes transmission forks, seats and seat belt recliners, planetary gears, brake shoes and steel backs, and there are nearly 100 kinds of fine blanking parts.

China's fine stamping die technology has made great progress during the "Eleventh Five-Year Plan" period, and has made a series of scientific research achievements in fine stamping process, materials, fine stamping presses, die frames, molds and lubrication. As of the end of 2008, there are nearly 20 provinces and cities in China that have professional precision production equipment, a total of more than 80 precision presses (excluding hydraulic mold bases), more than 5,000 employees in precision punching, and about 2,000 fine stampings. And has formed a number of independent precision punch die development demonstration base. Metal material is expanded from non-ferrous metal stamping to ferrous metal stamping. The blanking thickness of low-carbon steel, low-alloy steel and stainless steel reaches 12mm; the blanking thickness of non-ferrous metals such as aluminum alloy and copper alloy reaches l8mm; with the progress of mold materials and processing methods, and the spheronization process of punched sheets is improved. With popularization, some harder high-carbon steels, high-alloy steels, and other low-toughness materials such as nickel-base or cobalt-base alloys have also begun to be used to produce precision-punched parts. In addition, the proportion of self-developed progressive dies, precision transfer dies, transfer dies, and modular dies in domestic precision dies have been significantly improved, especially for advanced composite precision dies for complex parts of automotive transmission systems, which have been basically realized in China. The research, development and application of finite element numerical simulation technology, precision punching die structure optimization technology, precision punching die intelligent design and knowledge base technology for the fine blanking forming process have enhanced and enriched the technical connotation of China's fine blanking die. However, currently fine-blown enterprises are generally small in scale, have scattered resources, have low production efficiency, have shortages of talents and are incompletely equipped. Although there is a certain amount of development ability in the development of fine stamping dies, there is still a lack of experience in the development of complex fine stamping dies, especially fine stamping compound forming dies, and imported dies still occupy a large proportion.

Recently, the major science and technology project of the national "high-grade CNC machine tools and basic manufacturing equipment" undertaken by the Jinan No. 2 Machine Tool Group - "large-scale rapid and efficient CNC automatic stamping production line" passed the expert appraisal organized by the China Machinery Industry Federation, and its main technical performance indicators To reach the international advanced level.

According to Luo Baihui, head of the International Mould and Hardware & Plastics Industry Suppliers Association, the large-scale, fast and efficient automatic stamping production line is a large-scale stamping machine integrating machine, electricity and hydraulics and represents the latest development trend of today's international stamping technology. For a long time, high-grade stamping equipment in the Chinese auto industry has mainly relied on imports from abroad. Jinan No. 2 Machine Tool Group developed a "large-scale rapid and efficient CNC automatic stamping production line" to create a new record of 15 large-scale car parts per minute, becoming the world's highest level of high-speed automated stamping production line.

The project successfully developed by Jinan No.2 Machine Tool was implemented by Shanghai General Motors (Yantai) Dongyue Automobile Co., Ltd. 42000KN fully automatic flexible and rapid stamping production line. The first synchronization control continuous operation production mode was adopted. The entire line changeover time was only 3 minutes. The performance index is better than the similar products of foreign enterprises. It is the world's highest level of high-speed automated stamping production line. It is also the stamping production line with the most complete functions, efficiency, performance and standards applied in the domestic automotive industry. It has been selected as the national ten major landmarks engineering.

China's rapid and efficient automatic stamping technology has reached the international advanced level, but the application of precision punching technology in the manufacturing industry is still not popular enough, the system design and manufacturing technology and theory of the mold, the relevant equipment for fine rushing, fine oil rushing, technology and measurement equipment, etc. There is still a certain gap with the international advanced level.

1, fine stamping die life The current domestic and international precision blanking die gap is the low life expectancy. The sharpness of a sharpening die of an advanced country is generally 40,000 times more than the life of a steel plate, and the total life of the die is several hundred thousand times. At home, only 50% of foreign countries. The outstanding problems affecting the life of the die are the quality of the die material and the heat treatment. The current precision die is too expensive due to the imported die steel. In the case where the output is not large, the majority still uses domestic die steel. However, the quality of the domestic die steel is not good, and the process control and quality instability such as forging and heat treatment lead to great differences in overall die life.

2. Fine blunt material Fine blunt material is one of the core elements of fine scouring technology. Fine scouring requires uniform materials and moderate hardness. In order to achieve this goal, ball annealing should be carried out before fine scouring, and the spheroidizing rate should reach 95% or more; while most of the domestic materials are difficult to meet the requirements, the spheroidizing rate for spheroidizing annealing can only reach 50%. -90%. For the mold material, the current mold material can reach the precision punching requirements in the punching, but for the extrusion molding, the high strength and high toughness of the mold material can not meet the requirements at the same time. The properties (chemical and mechanical properties) and tolerances of domestic fine-punched sheet metal materials are inferior to those of imported materials. In addition, because the amount of material purchased for production batches does not meet the “minimum volume” required by steel mills, it has to be purchased at high prices or imported from abroad for a long period of time. These factors led to the increase in the cost of fine stampings, forcing many companies to use ordinary metal plates or simple fine blunts instead of fine blunt products, affecting the market development of fine blunt products. In addition, the study of fine blanking materials in foreign advanced countries has been developed from ordinary materials to high-strength fine blanking materials. It has become possible to achieve fine finishing of high hardness materials with a tensile strength of 9OON/mm2.

3, precision punch die design In order to improve production efficiency, the international continuous fine die has already dominated, reaching more than 70%, the production efficiency has been as high as 100 / min, the quality of precision punched parts to achieve zero million defects. At present, China has already possessed certain fine punching die design and development capabilities. However, currently the domestic fine punching industry still lacks experience in the design and development of complex fine punching dies, especially fine punching compound forming dies. Some companies have certain technical accumulations for certain specific products, but overall still have advanced levels with foreign countries. There is a big gap. The self-provision rate in China is less than 80%, among which the supply of medium and low-grade molds is oversupply, and the self-equipment rate of middle-to-high-grade molds is less than 60%. In addition, compared with foreign countries, the domestic mold life is generally low, generally 1/3 of foreign countries. The reasons involve fine die design, fine blanking materials, fine blanking die materials, precision punching die manufacturing precision, precision punching machine precision, lubrication oil, and fine punching manufacturing processes.

4. Production of Fine Punching Dies The research on the manufacturing process of fine die has accumulated a great deal of know-how in the world, especially for the century-old factory, and the technology accumulation has reached the expert level. However, there is still a long way to go for domestic accumulation of proprietary technology in precision die dies. In addition, the surface quality of the precision die mold is critical to the work performance and service life of the die, especially for the complex and high-precision fine-punch parts of high-end car drive and transmission systems, and the surface treatment technology of the die cavity in China. Began to pay attention, but there is still a clear gap between this technology and foreign advanced countries.

5, mold design stamping analysis capabilities Foreign precision finite element numerical simulation technology for fine blanking process and fine punching die force analysis simulation simulation check technology has reached a higher level, and has been applied to fine punch die design check And design verification, optimization of mold structure and so on. Although some universities and research institutes in China have carried out basic research work in this area, there is also a certain gap in the application of these technologies.

6. Fundamental research team Since the introduction of precision punching technology, Jingchong has always attracted the attention of scholars with its unique plastic forming method. At present, some colleges and research institutes have maintained more comprehensive and in-depth research on fine scouring technology and mold technology, but there is still a big gap compared with the international advanced level. At the international level, the Fine-Focus Research University Alliance promoted by Switzerland-based FEINTOOL has united five research institutes: the Institute of Virtual Manufacturing Technology (ETHZurich) of the Swiss Polytechnic Institute in Switzerland, the Institute of Machine Tools (RWTHAachen) at the Aachen University of Technology (Germany), Munich, Germany. The TUMunich Institute of Metal Forming and Casting at the University of Technology, the Ohio State University (OSU) and Shanghai Jiaotong University in China are the most active academic research teams in the world.

7. Mold standardization The internationally-recognized standard for precision punching dies is the German Society of Engineers standard VDI3345 (Feinschneiden). Leading foreign companies, such as the Swiss company FEINTOOL (VDI3345), formed a corporate standard on the basis of VDI3345, and was partially publicized. At present, China's major fine-blown companies hate who are based on VDI3345 and the company's corporate standards. In order to improve the overall capability of China's fine stamping mold industry and promote the development of industry standards, it is particularly important to formulate national or industry standards for fine stamping molds in China in the context of comprehensive international fine stamping mold standards and China's fine stamping mold industry development.

8. Fine-punch equipment: The foreign fine-punch equipment and fine-punch technology have been developed synchronously for hundreds of years. In particular, the Finetoo1 company in Switzerland has always been at the forefront of the fine-punching industry. Its fine-punch equipment, technical and accessory process accessories, and fine oil etc. Leading the world in level. In recent years, Japan's fine stamping equipment has also gradually risen, and it has occupied a large part of the mid-market of precision stamping equipment. However, our country is almost blank in this respect.

China's future fine stamping mold development goal is to meet the needs of the domestic precision stamping parts market, starting from the continuous precision stamping die design and manufacturing, improving the size of the fine stamping die industry, and continuing to expand the manufacturing capacity, in the development of sophisticated fine stamping die independent development capabilities, digital precision We have made significant progress in the research level of the die, the development and rational application of the fine stamping die materials, and the surface treatment technology of the fine die punching. We are working hard to improve the precision die technology of the company, narrow the gap with the international advanced level, and make the domestic fine blanking parts more competitive. Wide range of applications.

The focus of future product and technology development and major issues 1. Complex parts connection precision die design and manufacturing key technologies Research on complex parts Continuous precision die is the cutting-edge basic technology of fine blanking technology, as a leader to start research, hoping to promote the entire fine blanking technology in China A substantial increase. With key technologies such as synchronizer ring, clutch plate and longitudinal composite continuous fine blanking process and die and other complex parts continuous fine punching die as the breakthrough, the key technology of precision punching die design and manufacturing is researched, and the rapid improvement of China's fine punching die technology is achieved, shortening with advanced countries as soon as possible. difference.

2. The improvement of the life of precision punch die and related key technologies The study of tool life is a comprehensive reflection of the level of mold materials, processes and supporting products. The life of precision punch die is used as a leader to carry out technical research, which can solve the current domestic urgent need for precision die life too Low problems can also promote the technological development of mold materials, fine blanking processes, and supporting tooling and other ancillary products.

3, fine punching - precision forging composite process technology research and development fine punching, precision forging is the parallel development of two advanced manufacturing technology, fine stamping parts are too thick and need for precision forging, fine forging parts must be fine thin punching, both mutual Related, close. The basic idea for the development of precision forging and fine blanking is to find the combination of these two processes (such as gear parts with hubs and cam parts with short shafts), while the precision forging in China has a long history, and the level is very high. High, and in order to improve the overall level of fine scouring technology in China is a good way.