Domestic automotive mold production technology development trend

The core technology of automotive mold design and manufacturing is stamping process technology. Stamping process technology includes process design, molding surface design, cutting edge design, and all other technologies that involve the molding part of the product. Therefore, the level of stamping technology determines the level of mold design and manufacturing.

At present, the biggest gap between the level of domestic mold manufacturing and the international advanced level is reflected in the gap in the level of stamping technology. In the past, our stamping process technology mainly relied on human experience. With the shortening of the domestic high-quality body production cycle, it is impossible to rely on past experience to complete the stamping process.

I. The maturity and application of CAE software

CAE technology represented by finite element simulation analysis software has been applied in the international community for nearly 30 years. In the past 10 years, the plastic deformation theory has made great progress in the application of sheet metal forming technology, which has made the application of CAE technology in automotive mold manufacturing mature. Applying CAE to stamping process design can reduce the test mold by 50 %the above. At present, CAE technology has become an indispensable tool for foreign large-scale automobile and mold enterprises. The extensive application of CAE should be attributed to the vigorous development of CAE commercial software, among which the representative software includes: LS-DYNA3D software from Lawrence Livemore National Materials Laboratory of the United States; PAM-STAMP software from French ESI; OPTRIS software from French DYNAMICSOFTWARE; USA ETA's Dynaform software; Autoform's Autoform software from Switzerland.

These softwares have their own strengths and are very professional and practical in the analysis of sheet metal forming. At present, domestic first-class automotive mold companies have applied CAE software, and most of them are Autoform software applications. Tianjin Automotive Mold Co., Ltd. passed 2 years of hard work. The CAE application rate has reached 100%, which significantly shortens the mold debugging cycle.

Second, auxiliary stamping process design

Traditional CAE software can do analysis of formability, and require professionals to do a lot of pre-treatment, if the analysis results are not satisfactory, you need to start all over again. Because traditional CAE software is only a means of verification, it is mainly used for comparison of solutions and cannot be used as a process aid, thus causing CAE technology to be detached from the production process for a long time. Now CAE software has been developed to not only perform simple molding analysis but also participate in the entire process of stamping process. We call it computer-aided stamping process.

At present, CAE software has become an integral part of the mold design process. It is highly oriented to the end user, and the operator does not need deep CAE knowledge, nor does he need to use too much actual debugging experience to conveniently use it.

Third, the physical design and application

At present, domestic automotive mold companies have applied 2D CAD to structural design. Some companies apply 3D solid design to the design of some molds. Only a few companies can achieve 100% physical design. It should be said that physical design instead of 2D CAD is an inevitable trend of development.

The biggest advantage of the physical design is that the design process is very intuitive. It can describe the structure in detail and ensure the rationality of the design. It has obvious advantages in static and dynamic interference inspection of the mold, mold strength analysis and so on. Especially in the case of a large number of currently experienced designers, the newly engaged personnel of mold design can get started from physical design and can receive short-term training. After 3 or 4 months, they can successfully complete the mold entity under the guidance of others. design. In the past, a naturalist reached the same level, at least 1-2 years.

Fourth, the development of mold processing technology is the development of CNC machining technology

CNC machining progresses from simple surface machining to full CNC machining; from die processing to dovetail service to real CNC machining; from low-speed machining to high-speed, high-precision machining; and from manual processing, drawing processing to no-character, little-person or no-processing. Humanized processing. The currently focused processing technologies mainly include:

High-speed and high-precision machining; insert casting and high-efficiency machining; full CNC machining; few people unmanned processing; fitter manufacturing only unqualified repair.

(A) high-speed high-precision machining

At present, high-speed and high-precision machining has been widely adopted by international advanced companies, and the country is gradually becoming popular and mature. The purpose of high-speed machining is not simply to improve machining efficiency, but more importantly, high-precision machining with small steps and low residuals is realized at high speed.

The actual processing speed and accuracy of high-speed and high-precision machining programming surfaces are determined by the performance of the machine tool. Under certain conditions, the actual processing speed and precision are more dependent on the machining process and numerical control programming technology. We should pay attention to and study the influence of NC programming technology on machining accuracy and efficiency. For example, the instantaneous feed rate of the tool and the radius of curvature of the tool path are directly related. When the surface variation is very large, regardless of the set F value, the actual average feed speed will be very low. Moreover, if the F value is set too large, over-cutting and wiping will occur, which will seriously reduce the accuracy of the profile.

NC programming with high-speed and high-precision machining is much more troublesome than ordinary machining. Only a large amount of programming man-hours and programmers can complete the programming work, but this investment will be doubled in return for improvement of machining efficiency and precision.

(2) The processing of insert castings and high-efficiency processing of inserts occupies a large proportion of the total processing volume of the mold, and it is of great significance to effectively reduce this part of the working hours. The best processing methods are less cutting and no cutting. The current development is focused on the casting of inserts and the rational design to minimize the processing surface.

(3) Little People's Unmanned Processing Along with the proceduralization of mold processing and the centralization of machine tool processing, little people and unmanned processing are inevitable development trends. Unmanned increase can minimize labor costs and human error, and can achieve continuous production for 24 hours. In the current situation of higher and higher labor protection conditions and more holidays, fewer people and unattended processing technologies have become a natural choice.

(four) fitter manufacturing does not deserve little repair

One of the main purposes and important performances of improving the level of machining is to make the fitter's manufacturing only unqualified. The eradication of fitters is an ideal and slogan proposed by some foreign mold companies. It represents the development direction of mold manufacturing technologies in a concentrated manner; it realizes all-digital manufacturing and little-person unmanned processing through the improvement of CAD technology; it is realized through the improvement of CAM technology. The efficiency of the pliers industry such as assembly, grinding, and grinding has been improved. The success of mold debugging has been achieved through the improvement of CAE technology. The application of high-tech technologies such as computers and other automotive mold manufacturing technologies has reached a new stage.

The technologies that should be emphasized and developed at present are different from one company to another, but the summing up is nothing less than the three aspects of stamping process, structural design, and manufacturing technology, which correspond to the improvement of CAD/CAM/CAE technology. In the automotive mold manufacturing industry, computer application technology and numerical control processing technology are increasingly showing the role of their core technologies.