Development history of punch press

Archaeological discoveries in China show that the existing stamping dies in China were used to make bronzes more than 2,000 years ago, which proves that China's achievements in ancient stamping and stamping dies are leading in the world. 1953 Changchun No.1 automobile factory set up a stamping die workshop for the first time in China, and the factory began to manufacture automobile panel dies in 1958. China began to produce fine blanking dies in 1960s. After a long road of development, China has now formed more than 30 billion yuan (excluding statistics from Hong Kong, Macao and Taiwan, the same below). ) the production capacity of various stamping dies.

I. Market Situation of Stamping Die

China's stamping dies have made great progress in quantity, quality, technology and ability, but there is still a big gap compared with China's economic demand and the world's advanced level. Every year, a large number of large-scale, precise, complex and long-life high-end molds are still imported, especially for the panel dies of mid-to high-end cars, which are still mainly imported. Some low-grade simple stamping dies have been oversupplied and the market competition is fierce.

The market situation of stamping dies in China in 2004 is briefly described as follows:

According to the statistical data released by China Mould Industry Association, the total output of stamping dies in China in 2004 was about 22 billion yuan, of which 75 million dollars was exported, about 620 million yuan.

According to the statistics of China Customs, in 2004, China imported 566,543.8+0 million yuan of stamping dies, about 4.66 billion yuan. From the above figures, it can be concluded that the total size of the stamping die market in China in 2004 was about 26.66 billion yuan, of which the domestic market demand was 26.04 billion yuan, the total supply was about 2 1.38 billion yuan, and the market satisfaction rate was 82%. There are several specific situations that must be explained: First, most imported molds are large precision molds with high technology content, while most export molds are middle and low-grade molds with low technology content, so the market satisfaction rate of middle and high-grade molds with high technology content is lower than that of stamping molds, and the development of these molds has lagged behind the production of stamping parts, while the market satisfaction rate of middle and low-grade molds with low technology content is higher than that of stamping molds; Second, because the price of molds in China is far lower than that in the international market, it has certain competitiveness, so it has a good prospect in the international market. In 2005, the export of stamping dies reached $65.438+0.46 billion, an increase of 94.7% over 2004. Thirdly, Hong Kong-funded, Taiwan-funded and foreign-funded enterprises have developed rapidly in China in recent years. There is no exact statistical data on a large number of stamping dies produced and used by these enterprises, so they cannot be included in the above figures.

Second, the level of stamping die

In recent years, the level of stamping dies in China has been greatly improved. Large stamping dies have been able to produce a set of dies weighing more than 50 tons. It can also be produced in mid-range automobile panel dies. Many domestic enterprises have produced multi-position progressive dies with accuracy of 1~2μm and service life of about 200 million times. Fine dies with surface roughness Ra≤ 1.5μm, large-size (φ≥300mm) fine dies and medium plate fine dies have also reached a fairly high level in China.

1. Present situation of mould CAD/CAM technology

The development of mould CAD/CAM technology in China has a history of more than 20 years. The metal mold CAD/CAM system completed by Huazhong University of Science and Technology and Wuhan 733 Factory on 1984 * * is the first self-developed mold CAD/CAM system in China. The cold stamping die CAD/CAM system, which was jointly completed by Huazhong University of Science and Technology and Beijing Mould Factory, is the first cold stamping die CAD/CAM system developed by China. The CAD/CAM system of cold stamping die developed by Shanghai Jiaotong University was also completed in the same year. Since 1990s, domestic automobile industry has started to adopt CAD/CAM technology to design and manufacture molds. The National Science and Technology Commission 863 plans to use Dongfeng Motor Company as a CIMS application demonstration factory and Huazhong University of Science and Technology as a technical support unit. The CAD/CAPP/CAM integrated system of automobile body panel dies passed the appraisal in early 1996. During this period, FAW and Cheng Fei Automobile Mold Center introduced workstations and CAD/CAM software systems, which were applied to mold design and manufacturing, and achieved remarkable benefits. 1997 faw introduced CAE software for computer simulation of sheet metal forming process and began to use it in production.

Since the 20th century, CAD/CAM technology has been gradually popularized, and now all stamping die enterprises with certain production capacity basically have CAD/CAM technology. Some key enterprises also have various CAE capabilities.

Mold CAD/CAM technology can significantly shorten the mold design and manufacturing cycle, reduce production costs and improve product quality, which has become the consensus of people. During the "Eighth Five-Year Plan" and "Ninth Five-Year Plan" period, a large number of mold enterprises popularized computer drawing technology, and the utilization rate of NC machining became higher and higher, and a considerable number of CAD/CAM systems were successively introduced. For example, UG of American EDS, Pro/Engineer of American Parametric Technology Company, CADSS of American CV Company, DOCT5 of British DELCAM Company, CRADE and space-E of Japanese HZS Company, Cimatron of Israeli Company also introduced AutoCAD CATIA of automobile and panel dies and Euclid-IS of French Marta-Daravision Company. CAD/CAM technology has been widely used by domestic automobile panel die manufacturers. Both the design of DL drawing and the design of mold structure drawing have realized two-dimensional CAD, and most enterprises have transitioned to three-dimensional, and the production of general drawing has gradually replaced the production of part drawing. Moreover, the parametric design of mold has begun to move towards the technical development field of a few mold manufacturers.

In the aspect of stamping CAE software, in addition to imported software, Huazhong University of Science and Technology, Jilin University and Hunan University have all developed advanced software with independent intellectual property rights, which has been successfully applied in practice and produced good benefits.

Rapid Prototyping (RP) combined with traditional rapid and economical molds can rapidly manufacture large-scale automobile panel molds, which solves the problems that the original low-melting-point alloy molds rely on sample casting molds, and the mold accuracy is low and everything is difficult to manufacture. The rapid mold manufacturing based on 3D CAD models is realized, which indicates that RPM has been successfully applied to the trial production of large-scale automobile body panel molds.

Around the trial production of automobile body and the rapid manufacturing of large panel dies, some new rapid prototyping methods have appeared in recent years, such as dieless multi-point forming, laser shock, electromagnetic forming and so on, which have been applied to production at present. Both show the advantages of reducing costs and improving efficiency.

2, mold design and manufacturing capacity

Under the correct guidance of the national industrial policy, after decades of efforts, the design and manufacturing capacity of stamping dies in China has reached a high level, and many modern design and manufacturing technologies, including information engineering and virtual technology, have been applied in many die enterprises.

Nevertheless, there is still a big gap between the design and manufacturing capacity of stamping dies in China and the market demand and the international advanced level. These are mainly manifested in high-end cars and large and medium-sized automobile panel dies and high-precision stamping dies, and there is a big gap in design, processing technology and ability. The automobile panel die has the characteristics of great difficulty in design and manufacture, high quality and high precision, and can represent the level of the panel die. Although the design and manufacturing methods and means have basically reached the international level, there is still a certain gap in the mold structure cycle compared with foreign countries.

Multi-station progressive die and multifunctional die are the key varieties in the development of precision die in China, which indicates the advanced level of stamping die technology. The representative is the multifunctional die for precise automatic valve plate of iron core, which basically reaches the international level.

However, compared with foreign multi-station progressive dies, there is still a certain gap in manufacturing accuracy, service life, die structure and function.

The manufacturing technology of automobile panel dies has been continuously improved and perfected, and the use of high-precision and efficient processing equipment has become more and more extensive. High-performance five-axis high-speed milling machines and three-axis high-speed milling machines have been used more and more. The application of NC and DNC technology is becoming more and more mature, which can be used for ultra-precision machining of inclined machining. All these have improved the machining accuracy of the mold surface, improved the mold quality and shortened the mold manufacturing cycle.

Die surface strengthening technology has also been widely used. The ion nitriding technology with mature technology, no pollution and moderate cost is more and more recognized, and carbide coating treatment (TD treatment) and many plating (coating) technologies are more and more used in stamping dies. Vacuum treatment technology, full mold casting technology and cutting edge surfacing technology are becoming more and more mature. Laser cutting and laser welding technology have also been applied.