Explore the development trend of automobile die processing technology in China

In the development of automobile mold industry at home and abroad, the production and marketing demand, transformation and upgrading prospect of China’s automobile mold industry, mold technology presents the following major development trends.

1. The position of 3D mold design has been consolidated

The three-dimensional design of mold is an important content of digital mold technology and the basis of realizing the integration of mold design, manufacturing and inspection. Japanese Toyota and American general motors have realized the three-dimensional design of the die and achieved good application results. Some practices adopted in die 3D design abroad are worth learning from. In addition to realizing integrated manufacturing, another advantage of die three-dimensional design is that it is convenient for interference inspection and motion interference analysis, which solves a difficult problem in two-dimensional design.

2. The role of stamping process simulation (CAE) is more prominent

In recent years, with the rapid development of computer software and hardware, the simulation technology (CAE) of stamping process is playing a more and more important role. In developed countries such as the United States, Japan and Germany, CAE technology has become a necessary link in the process of die design and manufacturing. It is widely used to predict forming defects, optimize stamping process and die structure, improve the reliability of die design and reduce die test time. Many domestic automobile mould enterprises have also made remarkable progress in the application of CAE and achieved good results. The application of CAE technology can greatly save the cost of die test and shorten the development cycle of stamping die. It has become an important means to ensure the quality of die. CAE technology is gradually transforming die design from empirical design to scientific design.

3. Digital die technology has become the mainstream direction

In recent years, the rapid development of digital die technology is an effective way to solve many problems in the development of automobile die. The so-called digital mold technology is the application of computer technology or computer aided technology (CAX) in the process of mold design and manufacturing. The successful experience of applying computer-aided technology in automobile mold enterprises at home and abroad is summarized. The digital automobile mold technology mainly includes the following aspects: ① design for manufacturability (DFM), that is, considering and analyzing manufacturability in design to ensure the success of process. ② The auxiliary technology of mold surface design and the development of intelligent surface design technology. ③ CAE assists in analyzing and simulating the stamping process, predicting and solving possible defects and forming problems. ④ The traditional two-dimensional design is replaced by three-dimensional mold structure design. ⑤ CAPP, cam and CAT technology are used in the manufacturing process of die. ⑥ Under the guidance of digital technology, deal with and solve the problems in the process of die test and stamping production.

4. Rapid development of mold processing automation

Advanced processing technology and equipment is an important basis for improving productivity and ensuring product quality. In advanced automobile mould enterprises, CNC machine tools equipped with double worktables, automatic tool change device (ATC), photoelectric control system for automatic machining, workpiece online measurement system and so on are not uncommon. NC machining has developed from simple profile machining to comprehensive machining of profile and structural surface, and from medium and low speed machining to high-speed machining. Machining automation technology has developed very rapidly.

5. High strength steel sheet stamping technology is the future development direction

High strength steel is increasingly used in automobiles because of its excellent characteristics in yield ratio, strain hardening characteristics, strain distribution capacity and collision energy absorption. At present, the high-strength steels used in automotive stamping parts mainly include paint hardening steel (BH steel), dual phase steel (DP steel), transformation induced plastic steel (TRIP steel), etc. The ultra light body project (ULSAB) predicts that 97% of the advanced concept vehicle (ulsab-avc) launched in 2010 will be made of high-strength steel, and the proportion of advanced high-strength steel plate in the whole vehicle will exceed 60%, among which the proportion of dual-phase steel will account for 74% of the vehicle steel plate.

Now the mild steel series dominated by if steel will be replaced by high-strength steel plate series, and high-strength low-alloy steel will be replaced by dual phase steel and ultra-high-strength steel plate. At present, the application of high-strength steel plates for domestic automobile parts is mostly limited to structural parts and beam parts, and the tensile strength of the materials used is mostly below 500MPa. Therefore, quickly mastering the stamping technology of high-strength steel plate is an important problem to be solved in China’s automobile die industry.

6. New mold products are launched in time

With the development of automotive stamping production and automation, progressive die will be more widely used in the production of automotive stamping parts. Progressive die is a high-tech die product with great technical difficulty, high manufacturing accuracy requirements and long production cycle. Multi station progressive die will be one of the key die products developed in China. Progressive die forming is increasingly used for stamping parts with complex shape, especially for small and medium-sized complex stamping parts that need multiple pairs of dies according to traditional process.

7. Mold materials and surface treatment technology will be reused

The quality and performance of die materials are important factors affecting die quality, service life and cost. In recent years, in addition to the continuous introduction of a variety of high toughness and high wear resistance cold working die steels, flame quenched cold working die steels and powder metallurgy cold working die steels, the selection of cast iron materials for large and medium-sized stamping dies abroad is a development trend worthy of attention. Nodular cast iron has good strength, toughness and wear resistance, its welding performance, machinability and surface quenching performance are also good, and the cost is lower than that of alloy cast iron, so it is widely used in automobile stamping dies.