The rapid development of mold manufacturing technology has become an important part of modern manufacturing technology. Such as mold CAD/CAM technology, mold laser rapid prototyping technology, mold precision forming technology, mold ultra-precision machining technology, mold design using finite element method, boundary element method for flow, cooling, heat transfer process dynamic simulation technology, mold CIMS technology, has developed mold DNM technology and numerical control technology, covering almost all modern manufacturing technology.
Modern mold manufacturing technology is developing in the direction of accelerating information-driven, improving manufacturing flexibility, agile manufacturing and systematic integration.
High-speed 1. milling: the third generation of molding technology
High-speed milling not only has high processing speed and good surface quality of machining accuracy, but also has low temperature rise (the workpiece is only increased by 3 ℃) and small thermal deformation compared with traditional cutting, so it is suitable for processing temperature and thermal deformation sensitive materials (such as magnesium alloy, etc.). Due to the small cutting force, it can be applied to the processing of thin-walled and rigid parts. Reasonable selection of cutting tool amount, A series of advantages such as hard material (HRC60) processing can be realized. Therefore, high-speed milling technology is still a hot topic, it has to a higher agile, intelligent, integrated direction, become the third generation of molding technology.
2. EDM Milling "Green" Product Technology
From the perspective of foreign EDM machines, the performance, process index, intelligence and automation have reached a fairly high level. At present, the new trend abroad is to research and develop EDM machining technology (EDM machining technology). This new technology replaces the traditional cavity machining technology with forming electrodes. It uses high-speed rotating simple tubular electrodes for three-dimensional or two-dimensional contour machining (like CNC milling), so it is no longer necessary to manufacture complex forming electrodes, this is clearly a significant development in the field of EDM forming.
EDM technology progress at the same time, EDM safety protection technology more and more attention, many EDM machine tools have considered the safety protection technology. At present, the European Community has stipulated that machine tools without the "CE" mark cannot enter the European Community market, and the international market is paying more and more attention to the technical requirements of safety protection.
At present, the main problem of EDM machine tool radiation harassment, because it has a greater impact on safety and environmental protection, the international market is paying more and more attention to "green" products, as the leading equipment for mold processing EDM machine tool "green" product technology, will be the future must solve the problem.
3. a new generation of mold CAD/CAM software technology
At present, the United Kingdom, the United States, Germany and other countries and some institutions of higher learning research institutes to develop mold software, with a new generation of mold CAD/CAM software intelligence, integration, mold manufacturability evaluation and so on.
A new generation of mold software should be established from the mold design practice summarized a lot of knowledge. This knowledge has been systematically and scientifically organized to store the engineering knowledge base in a specific form and can be easily called by the mold. With the support of intelligent software, mold CAD no longer imitates the traditional design and calculation methods, and under the guidance of advanced design theory, the design results must be reasonable and advanced by making full use of the rich knowledge and successful experience of experts in this field.
The new generation of mold software designs the mold structure with three-dimensional ideas and intuitive feeling, and the generated three-dimensional structure information can be easily used for the evaluation of mold manufacturability CNC machining, which requires the mold software three-dimensional parametric feature modeling, molding process simulation, CNC machining process simulation and information exchange organization and management to achieve a considerable degree of perfection and a high level of integration. To measure the degree of software integration, it depends not only on whether the functional modules are complete, but also on whether these functional modules share the same data model and whether they form a global dynamic database in a unified way to realize comprehensive management and sharing of information to support the whole process of mold design, manufacturing, assembly, inspection, testing and production.
Mold manufacturability evaluation function A new generation of mold software is very important, not only to screen multiple programs, but also to evaluate the rationality and economy of the mold design process, and to provide a basis for modification of the mold designer.
A new generation of mold software, manufacturability evaluation mainly includes mold design and manufacturing cost estimation, mold assembly evaluation, mold parts manufacturing process evaluation, mold structure and forming performance evaluation. The new generation of software should also have assembly-oriented functions, because the mold function can only be reflected through its assembly structure. After adopting the assembly-oriented design method, the mold assembly is no longer a simple assembly of parts one by one, and its data structure can not only describe the mold function, but also define the relationship between the mold components and assembly characteristics, and realize the association of components, thus effectively ensuring the quality of the mold.
4. advanced rapid mold manufacturing technology
1, laser rapid prototyping technology (RPM) development speed, China has reached the international level, and gradually realize the commercialization. The world has been commercialized rapid prototyping process mainly SLA (stereolithography), LOM (layered split manufacturing), SLS (selective laser sintering), 3D-P (three-dimensional printing).
Tsinghua University was the first to introduce the equipment and technology of SLA250 (stereolithography or laser curing of photosensitive resin) from an American 3D company and carry out development and research. After several years of efforts, it has improved many times and launched the "M- RPMS-type multi-functional rapid prototype manufacturing system" (with layered solid manufacturing-SSM, melt extrusion molding-MEM), this is China's independent intellectual property rights in the world only has two kinds of rapid prototyping process system (national patent), has a good performance price ratio.
2, no mold multi-point forming technology with a highly adjustable punch group instead of the traditional mold for plate surface forming is another advanced manufacturing technology, no mold multi-point forming system to CAD/CAM/CAT technology as the main means, fast and economical to achieve three-dimensional surface automatic forming. Jilin University of Technology has undertaken the national key scientific and technological projects related to non-mold forming, and has independently designed and manufactured non-mold multi-point forming equipment with international leading level.
Compared with the Massachusetts Institute of Technology in the United States, the University of Tokyo in Japan, and the Tokyo Institute of Technology in Japan, this technology in my country is in a leading position in theoretical research and practical application, and is currently developing towards promotion and application.
3, resin stamping mold for the first time domestic car trial production has been successfully applied. FAW Mould Manufacturing Co., Ltd. has designed and manufactured 12 sets of resin moulds for the trial production of the new small red flag car. These 12 sets of moulds are respectively large and complex inner and outer covering parts such as trunk, engine hood, front, rear, left and right fenders. Its main characteristics are that the mould surface is based on the CAD/CAM processing main model, and is formed by pouring Swiss steam refined high-strength resin. The gap between convex and concave moulds is accurately controlled by imported special wax sheets, the manufacturing cycle can be shortened by 1/2 to 2/3, and the manufacturing cost can be saved by about 10 million yuan (12 sets of molds). It has opened up a new way for the trial production of small batch production of cars in China, which is the first in China. Swiss Ciba refinement experts believe that it can reach the international level in the 1990 s.
5. on-site mold detection technology
Precision mold development, the measurement requirements are getting higher and higher. Precision three coordinate measuring machine, for a long time by environmental constraints, rarely used in the production site. The new generation of three-coordinate measuring machine basically has temperature compensation and the use of anti-vibration materials, improve dust-proof measures, improve the reliability of environmental adaptability, so that it can be easily installed in the workshop to achieve the characteristics of the measurement site.
6. Mirror Polishing Mold Surface Engineering Technology
Mold polishing technology An important part of mold surface engineering, mold manufacturing process after processing an important process. At present, the domestic mold polishing to Ra0.05μm polishing equipment, abrasive and process, can basically meet the needs, and to throw to Ra0.025μm mirror polishing equipment, abrasive and process is still in the exploratory stage. With the large-scale application of mirror injection mold production, mold polishing technology has become a key issue in mold production. As there are still some problems in domestic polishing technology and materials, a large part of injection molds such as fool camera lens injection molds, CD, VCD discs and tools with high transparency requirements still rely on imports.
It is worth noting that the polishing of the mold surface is not only affected by the polishing equipment technology, but also by the mirror surface of the mold material, which has not attracted enough attention, that is, the polishing itself is restricted by the mold material. For example, when 45# carbon steel is used as an injection mold, when polished to Ra0.2μm, obvious defects can be seen by naked eyes. Continued throwing can only increase the brightness, while the roughness is hopeless to be improved. Therefore, imported mold materials are often used for domestic mirror mold production, such as Sweden's Yisheng Bai136 and Japan's Datong PD555, which can obtain satisfactory mirror quality.
The mirror mold material is not only a chemical composition problem, but also requires a series of advanced technologies such as vacuum degassing, argon protected ingot casting, vertical continuous casting and rolling, flexible forging, etc. during smelting, so that the mirror mold steel has a series of advantages such as less internal defects, fine impurity particle size, high dispersion degree, fine metal grain size, good uniformity, etc., so as to meet the requirements of polishing to mirror mold steel.
