Design and manufacture The rapid development of mold ma […]
Design and manufacture
The rapid development of mold manufacturing technology has become an important part of modern manufacturing technology. Such as the CAD/CAM technology of the mold, the laser rapid prototyping technology of the mold, the precision forming technology of the mold, the ultra-precision processing technology of the mold, and the finite element method and the boundary element method are used for the dynamics of the flow, cooling and heat transfer process in the mold design. Simulation technology, mold CIMS technology, mold DNM technology and numerical control technology that have been developed cover almost all modern manufacturing technologies.
Modern mold manufacturing technology is developing in the direction of accelerating information drive, improving manufacturing flexibility, agile manufacturing and system integration.
The third generation of molding technology
High-speed milling processing not only has high processing speed and good processing accuracy and surface quality, but also has low temperature rise compared with traditional cutting processing (the workpiece is only increased by 3℃), and the thermal deformation is small, so it is suitable for temperature and thermal deformation Sensitive materials (such as magnesium alloy, etc.) are processed; because of the small cutting force, it can be applied to the processing of thin-walled and poorly rigid parts; the reasonable selection of tools and cutting parameters can achieve a series of advantages such as hard materials (HRC60) processing. Therefore, high-speed milling processing technology is still a hot topic at present, and it has developed in the direction of higher agility, intelligence, and integration, and has become the third generation of mold making technology.
From the perspective of foreign EDM machine tools, whether in terms of performance, process indicators, intelligence, and automation, they have reached a very high level. The new trend in foreign countries is to carry out EDM machining technology (EDM creation processing technology). Research and development. This is a new technology that replaces the traditional molding electrode machining cavity. It uses high-speed rotating simple tubular electrodes for three-dimensional or two-dimensional contour machining (like CNC milling), so there is no need for complex manufacturing. This is obviously a major development in the field of EDM machining.
Japan's Mitsubishi Corporation has launched the EDSCAN8E EDM machine tool and has made new progress. This machine can automatically compensate for electrode loss. The dedicated CAM system developed for this machine on Windows 95 can be linked with general-purpose CAD such as AutoCAD, and can perform online precision measurement to ensure high-precision machining. In order to confirm whether the processed shape is abnormal or incomplete, the CAM system can also realize simulation processing.
With the advancement of EDM technology, people pay more and more attention to the safety and protection technology of EDM, and many EDM machine tools have considered safety protection technology. The European Community has stipulated that machine tools without the "CE" mark cannot enter the European Community market. At the same time, the international market is paying more and more attention to the requirements of safety protection technology.
The main problem of EDM machine tools is radiation harassment, because it has a greater impact on safety and environmental protection. As the international market pays more and more attention to "green" products, the "green" of EDM machine tools is the leading equipment for mold processing. Product technology will be a problem that must be solved in the future.
Mold surface engineering
Mold polishing technology is an important part of mold surface engineering and an important process for post-processing in the mold manufacturing process. Domestic mold polishing equipment, abrasives and processes that can be polished to Ra0.05μm can basically meet the needs, but mirror polishing equipment, abrasives and processes that need to be polished to Ra0.025μm are still in the groping stage. With the large-scale application of mirror injection molds in production, mold polishing technology has become a key issue in mold production. As there are still certain problems in domestic polishing technology and materials, a large part of injection molds such as point-and-shoot camera lens injection molds, CD, VCD discs, and tools with high transparency requirements still rely on imports.
It is worth noting that the mold surface polishing is not only affected by the polishing equipment and process technology, but also by the mirror finish of the mold material. This 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 it is polished to Ra0.2μm, obvious defects can be seen with the naked eye. If it continues to be thrown, it can only increase the brightness, but the roughness is hopeless to improve. Therefore, the domestic production of mirror molds is often Using imported mold materials, such as Sweden's ASSAB 136, Japan's Datong PD555, etc. can obtain satisfactory mirror finish.
Mirror mold material is not only a problem of chemical composition, but more importantly, a series of advanced processes such as vacuum degassing, argon protection ingot, vertical continuous casting and rolling, and soft forging are required during smelting, so that there are fewer internal defects in the mirror mold steel. A series of advantages such as fine particle size of impurities, high degree of dispersion, fine metal grain size, good uniformity, etc., to meet the requirements of mold steel polished to mirror surface