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Near net forming technology refers to the forming technology that can be used as a mechanical component after parts are formed and only a small amount of processing or no processing is needed.It is based on new materials, new energy, electromechanical integration, precision mold technologycomputer technology, automation technology, numerical analysis, simulation technology and other multi-disciplinary high-tech achievements, the traditional blank forming technology has been transformed from rough forming to high-quality, efficient, high-precision, lightweight, low-cost forming technology.
Chinese name
Near net shape technology
Features
Accurate shape and high dimensional accuracy
Advantages
Efficient, high-precision, lightweight and low-cost
It makes the formed mechanical components have accurate shape, high dimensional accuracy, shape and position accuracy and goodSurface roughness。This technology includes near net shape casting forming, precise plastic forming, precise connection, precise heat treatment modification, surface modification, high-precision mold and other professional fields, and is a comprehensive integration technology of new processes, new equipment, new materials and various new technological achievements.
Development trend
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Since the 1970s, governments and industrial circles in developed countries have invested a lot of money and manpower in near net forming technology, which has developed rapidly. Because of its outstanding contribution to market competitiveness, this technology has been listed as a key technology by the U.S. and Japanese governments and enterprises that affected competitiveness in the 1990s,The growth rate of its output value is also much higher than that of the manufacturing industry.The main development trends are:
Continuous development of new near net shape forming technology
Industrial developed countries have been committed to developing new near net shape forming technologies, and have made great progress in all parts involved in this topic, so the proportion of near net shape forming, the precision of formed parts, and the complexity of formed parts have been greatly improved.For example, the wall thickness of automobile cylinder castings has reached 3-4 mm, many car gears can be produced by cold extrusion, and the tooth profile is no longer processed.SedanConstant velocity universal jointParts are very complex parts, which can be produced by precise plastic forming technology.Car connecting rod not only has high dimensional accuracy, but also has small weight deviation. The weight accuracy of car connecting rod can be controlled below 3-4%. These technologies have promoted the reduction of car dead weight and the improvement of car performance. With the improvement of forming accuracy, a large number of near net forming technologies have been developed.The development of new materials has promoted the research and development of new forming technologies, the development of high-density energy (laser, plasma beam, electron beam, etc.) and its application in near net forming, and also introduced a number of new near net forming processes.All these make this technology form a colorful and competitive development situation.In China, the proportion of near net forming technology in the whole forming manufacturing production is still relatively low. The overall level of precision of formed parts is 1-2 levels lower than that of developed countries on average. Some new technologies are only adopted by a few enterprises. Many complex and difficult to form parts cannot be produced in China, and some advanced forming equipment, mechanical operators,A large part of high-level automated production lines cannot be provided in complete sets at home, so the overall level is 15-25 years behind that of foreign countries.
Applying process simulation technology to optimize net forming process parameters
The traditional forming technology is based on experience and experimental data. To develop a new part forming process, a large number of modifications and adjustments are often required during production.The development of computer and computing technology, especially the development of computing technology for nonlinear problems, has made it possible to simulate, analyze and optimize the forming process. Many commercial software such as casting, forging, panel stamping, mold CAD/CAM and so on have been formed through a lot of work abroad, which has strongly promoted the development of near net forming technology. China has done a lot of work in simulation analysis research,However, the power is scattered, the investment of each unit is insufficient, and there are many individual studies, so there are few commercial software. Now foreign forming software has entered the domestic market one after another, which also exposes problems such as high cost and unsuitability to national conditions.How to organize domestic forces.Starting from the national conditions, it is a problem that should be solved at present to organize superior units, carry out process simulation and optimization, and develop advanced and applicable software.
Continuously develop robots and manipulators suitable for near net shape production
Near net forming is usually mass production, which requires the construction of automatic production lines and corresponding manipulators and robots. Due to the diversity of working environments, near net forming manipulators and robots usually work at high temperatures, so near net forming manipulators and robots have different characteristics from ordinary robots for cold processing and assembly,Through years of work, we have mastered a series of design and manufacturing technologies for forming robots and robots. In addition to introducing, digesting and developing some of the forming robots and robots for production in China, which can meet the needs of enterprises, most of the products also need to be researched and developed or absorbed through the introduction, digestion and absorption of development to gradually form a series.
Develop and use new technologies to improve productivity
Most of the near net shape of mass production in foreign countries are produced by automatic lines, which has the advantages of high productivity, stable quality, good working conditions, etc. The research and construction of such production lines in the industrial developed countries have been decades of history, and with the demand for product personalization, some flexible production lines have emerged.
Some key enterprises in China successively established some near net forming production lines relying on imported equipment in the early 1970s and 1980s (for example, in the late 1970s, FAW purchased 12000 tons of German OMCOHot die forging pressAutomatic production line).Since then, through the introduction and independent development, China has been able to rely on domestic technology and equipment to build a hot die forging production line in the early 1990s.There are still many production line construction technologies that have not been mastered in China. These technologies must be mastered in the early decade of the next century to build production lines and flexible production lines with different degrees of automation according to the needs of domestic enterprises.
Attach importance to quality control and improve quality consistency
In order to ensure product quality, foreign enterprises, on the one hand, strengthen management and do a good job in the quality control of the whole production process, on the other hand, ensure the stability of near net shape production quality through automation and intelligent control in the production process, and develop various online testing and nondestructive testing technologies and instruments, and conduct research and application of statistical process control technology,Thus, the quality and precision of the formed parts are reliable.There is still a big gap in the above key technologies in China, and they also need to be mastered as soon as possible to ensure the quality of the final formed parts.
Virtual Manufacturing and Network Manufacturing for Developing Near Net Shaping Technology
With the development of computer and network technology, virtual manufacturing and network manufacturing have begun to receive attention and development abroad in recent years. China's near net shape enterprises are generally small in scale, lack of technical strength, and lack of information.Due to the rapid development of China's network information industry in recent years, a number of scientific research institutions and schools in China have accumulated a number of research results and software. If enterprises, research institutions and schools are organized through associations, societies and productivity promotion centers to carry out virtual manufacturing and network manufacturing, and provide paid services, it may be an effective way to commercialize scientific research results,It will also be an effective way to improve the overall technical level of the industry.
Objectives of the Tenth Five Year Plan
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target
Through scientific and technological research and industrialization, the near net forming technology can catch up with or approach the international advanced level in major aspects, and some technologies are innovative;Through the maturity, industrialization and integration of key technologies, we can not only provide advanced complete technologies to enterprises, but also provide individual technologies to meet the needs of enterprises. We will strive to achieve that domestic technologies can meet 85 - 90% of the needs of enterprises, and can basically block the import of complete sets of technical equipment in most directions.
Main research contents
New near net forming technology and its industrialization: including "near net forming casting", "precision plastic forming", "high-quality and efficient precise connection", "precision heat treatment modification", "high-quality and efficient surface modification and coating", "complex and high-precision mold" and other technologies and their comprehensive applications. Research is carried out on new technologies and common technologies urgently needed by enterprises in the above direction and covering a wide range of areas,Provide new process, new method and new equipment, accumulate perfect technical data and achieve practicality.
Simulation analysis and optimization of near net forming process: research and solve the key technology of forming process simulation, make 3D simulation software perfect, mature and commercialized, and provide optimized process parameters for near net forming.
Manipulators and robots for near net forming production line: study the typical manipulators and robots (forging, stamping, die-casting, welding, etc.) required for near net forming production line to make them serialized, mature and meet the needs of production line construction.
Near net shape forming automatic production line and flexible production line construction technology: take process technology as the core to study and master the near net shape forming automatic production line construction technology, focus on the research of production line control and online detection technology, so as to build production lines with different mechanization and automation levels according to the enterprise's production program and possible funds, and also according to the development needs,Build some flexible production lines.
Quality control technology in the production process: through the research and application of online intelligent control technology, nondestructive testing technology and statistical process control technology, the whole process quality control of near net formation is achieved, thus ensuring the final product quality.
Virtual manufacturing and network manufacturing technology of near net forming technology: in view of the characteristics of many small and medium-sized enterprises in the industry and low technical level of domestic enterprisesProductivity Promotion CenterClosely combine to establish virtual manufacturing and network manufacturing system.
