What kinds of molds are there? What is the main work of mold design? Does the mold design need to open CNC machine tools such as machining centers? Or a single pre-computer design?

Mold manufacturing technology has developed rapidly and has become an important part of modern manufacturing technology. Such as CAD/CAM technology, laser rapid prototyping technology, precision forming technology, ultra-precision machining technology, finite element method and boundary element method, dynamic simulation technology of flow, cooling and heat transfer process, CIMS technology, DNM technology, numerical control technology, etc., which 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. ?

1. high-speed milling: the third generation forming technology?

High-speed milling not only has high machining speed, good machining accuracy and surface quality, but also has low temperature rise (the workpiece is only 3℃) and small thermal deformation compared with traditional cutting, so it is suitable for machining materials sensitive to temperature and thermal deformation (such as magnesium alloy). Because of the small cutting force, it can be applied to the processing of thin-walled and rigid parts; A series of advantages, such as machining hard materials (HRC60), can be realized by reasonably selecting tools and cutting parameters. Therefore, high-speed milling technology is still a research hotspot at present, and it is developing in the direction of higher agility, intelligence and integration, becoming the third generation modeling technology. ?

Second, EDM milling and "green" product technology?

From the point of view of foreign electric machining machine tools, the performance, process index, intelligence and automation have reached a high level. At present, the new trend abroad is to develop EDM generating machining technology, which is a new technology to replace the traditional cavity machining with special-shaped electrodes. It uses a simple tubular electrode rotating at high speed to process three-dimensional or two-dimensional contours (like CNC milling), so it is no longer necessary to manufacture electrodes with complex shapes. ?

Recently, Mitsubishi Corporation of Japan launched EDSCAN8E EDM machine tool and made new progress. This machine can automatically compensate for electrode loss. The special CAM system developed for this machine on Windows95 can be linked with general CAD such as AutoCAD, and can be used for on-line precision measurement to ensure high-precision machining. In order to confirm whether the machining shape is abnormal or incomplete, the CAM system can also realize simulation of machining. ?

With the development of EDM technology, people pay more and more attention to the safety and protection technology of EDM, and many electric machining machines have considered the safety protection technology. At present, the European Union has stipulated that machine tools without the "CE" mark cannot enter the EU market, and at the same time, the international market is paying more and more attention to the requirements of safety protection technology. ?

At present, the main problem of EDM machine tools is radiation interference, because radiation interference has great influence on safety and environmental protection. With the international market paying more and more attention to "green" products, the "green" product technology of EDM machine tool, as the leading equipment for mold processing, will be a difficult problem to be solved in the future. ?

Third, the new generation of mold CAD/CAM software technology?

At present, the mold software developed by Britain, America, Germany and some universities and research institutes in China has the characteristics of intelligence, integration and evaluation of mold manufacturability of the new generation of mold CAD/CAM software. ?

The new generation of mold software should be based on a lot of knowledge summarized from mold design practice. After systematic and scientific arrangement, this knowledge is stored in the engineering knowledge base in a specific form and can be easily called by molds. With the support of intelligent software, mold CAD is no longer an imitation of traditional design and calculation methods, but under the guidance of advanced design theory, making full use of the rich knowledge and successful experience of experts in this field, and its design results are bound to be reasonable and advanced. ?

The new generation of mold software designs the mold structure with three-dimensional thoughts and intuitive feelings, and the generated three-dimensional structure information can be easily used for mold manufacturability evaluation and NC machining, which requires the mold software to achieve a perfect degree and high degree of integration in three-dimensional parametric feature modeling, molding process simulation, NC machining process simulation, information exchange, organization management and so on. The degree of software integration depends not only on whether the functional modules are complete, but also on whether these functional modules use the same data model and form a global dynamic database in a unified way to realize the comprehensive management and sharing of information to support the whole process of mold design, manufacturing, assembly, inspection, testing and production. ?

The evaluation function of mold manufacturability is very important in the new generation of mold software. It is necessary to screen several schemes, evaluate the rationality and economy in the process of mold design, and provide a basis for mold designers to modify. ?

In the new generation of mold software, manufacturability evaluation mainly includes the estimation of mold design and manufacturing cost, the evaluation of mold assembly, the evaluation of mold parts manufacturing manufacturability, the evaluation of mold structure and formability, etc. ? The new generation of software should also have the function of assembly-oriented, because the function of mold can only be reflected by its assembly structure. After adopting the assembly-oriented design method, the die assembly is no longer a simple one-by-one assembly, and its data structure can not only describe the function of the die, but also define the assembly characteristics of the relationship between die parts, thus realizing the association of parts and effectively ensuring the quality of the die. ?

Advanced rapid tooling manufacturing technology?

1, with the rapid development of laser rapid prototyping technology (RPM), China has reached the international level and gradually realized commercialization. The commercialized rapid prototyping technologies in the world mainly include SLA (light curing rapid prototyping), LOM (layered separation manufacturing), SLS (selective laser sintering) and 3D-P (three-dimensional printing). ?

Tsinghua University took the lead in introducing SLA250 (light curing rapid prototyping or photosensitive resin laser curing) equipment and technology from American 3D company, and carried out research and development. After several years' efforts, the "M-RPMS Multifunctional Rapid Prototyping Manufacturing System" (-SSM, -MEM) has been perfected and introduced, which is the only system in the world with independent intellectual property rights in China and two rapid prototyping processes (national patents). ?

2. Die-less multi-point forming technology is another advanced manufacturing technology, which uses the height-adjustable punch group to form the surface of sheet metal instead of the traditional die. The dieless multi-point forming system takes CAD/CAM/CAT technology as the main means to realize the automatic forming of three-dimensional surfaces quickly and economically. Jilin University of Technology undertook the national key scientific and technological project of dieless forming, and independently designed and manufactured the dieless multi-point forming equipment with international leading level. ?

Compared with MIT, Tokyo University and tokyo institute of technology, this technology in China is in a leading position in theoretical research and practical application, and is now developing in the direction of popularization and application. ? 3. The resin stamping die was successfully applied to the trial production of domestic cars for the first time. FAW Mold Manufacturing Co., Ltd. designed and manufactured 12 sets of resin molds for the trial production of the brand-new small red flag car. This 12 set of dies is a drawing die for large-scale complex inner and outer covering parts such as luggage, hood, front, rear, left and right fender. Its main feature is that the mold surface is based on the main model of CAD/CAM processing, and the high-strength resin extracted from Swiss Ciba is used for casting. The gap between the convex and concave dies is precisely controlled by the imported special wax sheet, so the die size accuracy is high, the manufacturing cycle can be shortened by one-half to two-thirds, and the manufacturing cost can be saved by about100000 yuan (12 sets of dies). It has opened up a new road for the trial production and small batch production of cars in China and is the first in China. Experts in Ciba Specialization in Switzerland believe that it can reach the international level in the 1990s. ?

5. On-site mold inspection technology?

With the development of precision molds, the requirements for measurement are getting higher and higher. Precise CMM, limited by the environment for a long time, is rarely used in the production site. The new generation of CMM basically has the characteristics of temperature compensation, using vibration-proof materials, improving dust-proof measures, improving environmental adaptability and reliability, etc., which is convenient for installation and use in the workshop and realizes on-site measurement. ?

Six, mirror polishing mold surface engineering technology?

Mold polishing technology is an important part of mold surface engineering and an important post-treatment process in mold manufacturing. At present, the polishing equipment, abrasives and technology for polishing molds to Ra0.05μm in China can basically meet the needs, while the mirror polishing equipment, abrasives and technology for polishing molds to Ra0.025μm are still in the exploration stage. With the large-scale application of mirror injection mold in production, mold polishing technology has become a key issue in mold production. Because there are still some problems in domestic polishing technology and materials, a large part of injection molds, such as injection molds for camera lenses, CDs, VCD discs and tools with high transparency requirements, still rely on imports. ?

It is worth noting that mold surface polishing is not only affected by polishing equipment and technology, but also by the mirror degree of mold materials, which has not been paid enough attention to, that is to say, polishing itself is restricted by mold materials. For example, when 45# carbon steel is used as an injection mold and polished to Ra0.2μm, obvious defects can be seen by naked eyes. If you throw it down, it will only increase the brightness, and roughness is hopeless. Therefore, at present, imported mold materials are often used in mirror mold production in China, such as Sweden's Yishengbai 136 and Japan's Datong PD555. And a satisfactory mirror degree can be obtained. ?

The material of mirror die steel is not only a matter of chemical composition, but also a series of advanced technologies, such as vacuum degassing, argon shielded ingot casting, vertical continuous casting and rolling, and flexible forging, are needed in smelting, so that mirror die steel has a series of advantages, such as less internal defects, fine impurity particle size, high dispersion, fine metal grains and good uniformity, to meet the requirements of polishing mirror die steel.