Mold manufacturing technology has developed rapidly, has become an important part of modern manufacturing technology. Such as mold CAD / CAM technology, mold laser rapid prototyping technology, mold precision molding technology, mold ultra-precision machining technology, mold design using the finite element method, the boundary element method for flow, cooling, heat transfer process dynamic simulation technology, mold CIMS technology, has been developed mold DNM technology, as well as numerical control technology, etc., covering almost all modern manufacturing technology.
Modern mold manufacturing technology toward accelerating information-driven, improve manufacturing flexibility, agile manufacturing and systematic integration direction.
First, high-speed milling: the third generation of mold technology
High-speed milling processing not only has a high processing speed and good processing accuracy surface quality, and compared with traditional cutting processing has a low temperature rise (processing workpiece only 3 ℃), thermal deformation is small, and thus suitable for temperature and thermal deformation sensitive materials (such as magnesium alloys, etc.) processing; but also due to the cutting force is small, it can be applied to the processing of thin-walled and rigidity of poor parts; the reasonable choice of cutting tool cutting dosage, you can realize the hard material ( HRC60) processing and a series of advantages. Therefore, high-speed milling processing technology is still the current hot topic, it has been to more sensitive, intelligent, integrated direction, become the third generation of mold making technology.
Second, EDM milling “green” product technology
From the point of view of foreign electric processing machine tools, whether from the performance, process indicators, intelligence, automation has reached a fairly high level, the current new trend in foreign countries to carry out EDM milling technology (EDM processing technology) research and development, which is an alternative to the traditional molding electrodes for cavity processing of new technologies, it is a high-speed rotating simple tubular electrode for three-dimensional or two-dimensional contouring process (like CNC milling), therefore It is no longer necessary to manufacture complex molding electrodes, which is obviously a major development in the field of EDM machining.
EDM technology advances at the same time, EDM safety protection technology is increasingly being emphasized, many EDM machine tools are considered safety protection technology. At present, the European Community has stipulated that no “CE” mark machine tools can not enter the European Community market, while the international market is also paying more and more attention to the safety protection technology requirements.
At present, EDM machine tools, the main problem of radiation harassment, because it is on the safety, environmental protection has a greater impact on the international market is paying more and more attention to the “green” products, as the leading equipment for mold processing EDM machine tools, “green” product technology, will be the future! Must solve the problem.
Third, a new generation of mold CAD / CAM software technology
At present, Britain, the United States, Germany and other countries and some of China's institutions of higher learning and research institutes to develop mold software, with a new generation of mold CAD / CAM software intelligence, integration, mold manufacturability evaluation and other characteristics.
A new generation of mold software should be built from the mold design practice summarizes a large amount of knowledge. This knowledge has been systematized scientific organization, in a specific form of storage engineering knowledge base and can be easily called by the mold. Intelligent software support, mold CAD is no longer on the traditional design and calculation methods to imitate, and advanced design theory under the guidance of the full use of the rich knowledge of experts in the field of successful experience, the design results will inevitably have the rationality of the advanced.
A new generation of mold software to three-dimensional thinking, intuitive feeling to design the mold structure, generated by the three-dimensional structure of the information can be easily used for mold manufacturability evaluation of CNC processing, which requires mold software three-dimensional parametric features modeling, molding process simulation, CNC machining process simulation and information exchange organization and management to reach a fairly perfect degree and have a high level of integration. Measure the degree of software integration, not only to see whether the functional modules are complete, but also to see whether these functional modules share the same data model, whether the formation of a global dynamic database in a unified manner to achieve integrated management and sharing of information in order to support the mold design, manufacturing, assembly, inspection, testing and commissioning of the whole process.
Mold manufacturability evaluation function of a new generation of mold software plays a very important role, both for the screening of multiple programs, but also to assess the rationality of the mold design process economy, and provide mold designers to modify the basis.
A new generation of mold software, manufacturability evaluation mainly includes mold design and manufacturing cost estimates, mold assembly evaluation, mold parts manufacturing process evaluation, mold structure and forming performance evaluation. A new generation of software should also be assembly-oriented function, because the mold function only through its assembly structure can be reflected. After the use of assembly-oriented design methods, mold assembly is no longer a part by part simple assembly, its data structure can not only describe the function of the mold, but also define the relationship between the mold parts assembly characteristics, parts and components to achieve the association, and thus can effectively ensure the quality of the mold.
Fourth, advanced rapid mold manufacturing technology
1, laser rapid prototyping technology (RPM) development speed, China has reached the international level, and gradually commercialized. The world has been commercialized rapid prototyping process mainly SLA (stereo lithography), LOM (layering and manufacturing), SLS (selective laser sintering), 3D-P (three-dimensional printing).
Tsinghua University was the first to introduce the U.S. 3D company SLA250 (stereolithography or photosensitive resin laser curing) equipment and technology and development and research, after several years of hard work, many times to improve, improve, and launch the “M-RPMS-type multi-functional rapid prototyping system” (with a layered solid manufacturing-SSM, melt extrusion molding-MEM), and the “M-P” (three-dimensional printing). (with layered solid manufacturing - SSM, melt extrusion molding - MEM), which is China's own intellectual property rights the world's only two rapid prototyping process system (national patent), with a good performance-price ratio.
2, moldless multi-point forming technology with highly adjustable punch group instead of the traditional mold for plate surface forming and an advanced manufacturing technology, moldless multi-point forming system to CAD / CAM / CAT technology as the main means to quickly and economically realize the three-dimensional surface of the automatic forming. Jilin University of Technology has undertaken the national key scientific and technological research projects on moldless forming, has independently designed and manufactured with the international leading level of moldless multi-point forming equipment.
This technology in China and the United States Massachusetts Institute of Technology, Japan, Tokyo University, Tokyo Institute of Technology, Japan, compared to the theoretical research and practical applications are in a leading position, is now moving towards the promotion and application of the development.
3, resin stamping die for the first time in the domestic car trial production was successfully applied. FAW Mould Manufacturing Co., Ltd. designed and manufactured 12 sets of resin molds for the new small red flag sedan modified trial production, the 12 sets of molds were luggage, engine cover, front and rear left and right wing panels and other large complex internal and external coverings stretching molds, and its main features of the mold surface to CAD / CAM machining of the main model as a benchmark, the use of Switzerland, Ciba refinement of high-strength resin casting, the convex-concave die gap using imported special The gap between convex and concave molds is accurately controlled by imported special wax sheet, the mold has high dimensional accuracy, the manufacturing cycle can be shortened by one-half to two-thirds, and the manufacturing cost can be saved about 10 million yuan (12 sets of molds). It opens up a new way for the trial production of small batch production of cars in China, which is the first one in China. The relevant experts of Swiss Ciba Precision believe that it can reach the international level in the 1990s.
Fifth, on-site mold testing technology
Precision mold development, more and more high requirements for measurement. Precision three-coordinate measuring machine, for a long time by the environmental restrictions, few production site use. A new generation of three-coordinate measuring machine basically have temperature compensation and the use of vibration-resistant materials, improve dust measures, improve environmental adaptability using reliability, so that it can be conveniently installed workshop use, in order to achieve the characteristics of the measurement site.
Six, mirror polishing mold surface engineering technology
Mold polishing technology mold surface engineering is an important part of the mold manufacturing process after treatment of important processes. At present, the domestic mold polishing to Ra0.05μm polishing equipment, abrasives and technology, can basically meet the needs, and to throw to Ra0.025μm mirror polishing equipment, abrasives and technology is still in the groping stage. With the large-scale application of mirror injection mold production, mold polishing technology has become a key issue in mold production. Because of the domestic polishing technology and materials and other aspects of the problem still exists, so such as stupid camera lens injection mold, CD, VCD discs and tools with high transparency requirements of the injection mold is still a large part of the dependence on imports.
It is worth noting that the mold surface polishing is not only affected by the polishing equipment technology, but also by the mold material mirror degree of influence, which has not yet attracted sufficient attention, that is to say, polishing itself by the mold material constraints. For example, with 45 # carbon steel to do injection mold, polishing to Ra0.2μm, the naked eye visible obvious defects, continue to throw down can only increase the brightness, and the roughness has no hope of improvement, so the current domestic production of mirror surface molds are often used in imported mold materials, such as Sweden Shengbay 136, Japan, such as Tatung PD555 can be satisfied with the degree of mirror.
Mirror mold material is not only the chemical composition of the problem, but also the main smelting requirements using vacuum degassing, argon protection ingot, vertical continuous casting and rolling, soft forging, and a series of advanced technology, so that the mirror mold steel with fewer internal defects, impurities fine particle size, high dispersion, metal grain size, uniformity, and so on a series of advantages to achieve the polished to the mirror surface of the mold steel requirements.