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 Company, Pro/Engineer of American Parametric Technology Company, CADS5 of American CV Company, DOCT5 of British DELCAM Company, CRADE and space-E of Japanese HZS Company, Cimatron of Israeli Company, AutoCAD and CATIA and Euclid-IS of French Marta-Daravision Company, etc. have also been introduced one after another. CAD/CAM technology is widely used by domestic automobile panel die manufacturers. Two-dimensional CAD has been realized in the design of DL drawing and die structure drawing, 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 also begun to move towards the technical development field of a few mold manufacturers.
In 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 production practice and produced good benefits.
Rapid prototyping technology (RP) is combined with traditional rapid and economical molds to rapidly manufacture large-scale automobile panel molds, which solves the problems of low mold precision, low parts precision and difficult sample making of the original low-melting-point alloy molds, realizes rapid mold manufacturing based on 3D CAD models, ensures the parts precision, and provides a guarantee for the development of new models in the automobile industry and the rapid trial production of automobile bodies. It marks the application of RPM technology in large automobile body.
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. 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.
Even so, 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, and the mold structure and function are close to the international level, which has made a big step forward in the localization process of automobile molds, there is still a certain gap compared with foreign countries in manufacturing quality, accuracy and manufacturing cycle.
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 bevel machining and ultra-precision 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. There are seven categories of stamping dies, some of which are called by their customers. At present, it is urgent to develop automobile panel dies, multi-functional multi-position progressive dies and fine blanking dies. There is a great contradiction between production and demand of these molds now, and their development prospects are very good.
The development focus of automobile panel dies is the medium and high-grade car panel dies with high technical requirements, especially the outer panel dies. Stamping dies, large-scale multi-position progressive dies and continuous dies for high-strength plates and unequal thick plates will develop rapidly in the future.
The development of multi-functional multi-station progressive die focuses on high precision, high efficiency and large-scale long-life progressive die.
The focus of fine blanking die development is the large-scale fine blanking die for thick plate, and its accuracy is constantly improving. In the future, the development trend of mold technology is mainly information, high speed and high precision. Therefore, in terms of design technology, the development focus is to vigorously promote the application of CAD/CAE/CAM technology to continuously improve efficiency, especially the computer simulation analysis technology of sheet metal forming process. Mould CAD/CAM technology should develop in the direction of humanization, integration, intelligence and networking, and improve the professional level of mould CAD/CAM system.
In order to improve the application level of CAD, CAE and CAM technology, it is very important to establish a complete mold database, develop an expert system and improve the practicability of the software. In terms of machining technology, the development focus is on high-speed machining and high-precision machining. At present, high-speed machining mainly develops high-speed milling, high-speed grinding and polishing, high-speed electrical machining and rapid die making technology. At present, high-precision machining is mainly to develop all kinds of precision machining of die parts with precision below 1μm and surface roughness ra≤0. 1 μm, so as to improve the standardization of dies and the production and supply of die standard parts, which is also one of the key points of stamping die technology development.
In order to improve the service life of stamping die, various technologies such as die surface strengthening and superhard treatment are also the focus of development.
It is the focus of stamping die technology development to form an all-round solution of digital die manufacturing, system integration, reverse engineering, rapid prototyping/die manufacturing and computer-aided application technology, provide die development and engineering services, and comprehensively improve the enterprise level and die quality. Other development priorities and prospects are very rich in connotation. Here we only analyze three aspects: management, specialization and standardization, and industry adjustment.
Enterprise management is a systematic project, a science and technology. Compared with mold enterprises in developed countries, in a sense, our management is even behind our technology. Therefore, it is very important to improve the management level and the task is heavy. At present, there are many management forms of mold enterprises, and each form has its own adaptive object. However, doing a good job in information construction and gradually realizing information management have become the development direction, and the industry has also recognized this. Due to historical and institutional reasons, the level of specialization and standardization of molds in China has been very low, and the degree of specialization of stamping molds is lower than that of plastic molds and die-casting molds. This has hindered the development of stamping die to some extent. According to the specialization degree of molds at home and abroad,
1) Mold production is independent of other products, specializing in the production of molds for external supply;
2) Specializing in the production of a certain type of mold (such as stamping mold) according to the mold type;
3) In a certain mold, according to its service object or mold technology and size, select a certain mold (such as automobile panel mold, multi-station progressive mold, fine blanking mold, etc.). ) professional production;
4) Specializing in the production of some parts in the mold (such as mold base, punch, elastic element, etc.). ) is a mold manufacturing enterprise;
5) Carry out specialization and cooperation according to the process. For example, at present, companies specializing in mold design, enterprises specializing in cavity machining or electro-machining cooperation, enterprises specializing in measurement or heat treatment and enterprises specializing in polishing business have promoted the development of mold industry. However, the road to specialization is still far away, and we must speed up the process to adapt to the situation. Therefore, this is also the focus of development.