Analysis And Simulation Of The Complete Process Chain Of Multi-position Progressive Stamping

The rapid development of automobile industry in our country provide a considerable market demand space for automobile components, more than95%of them need to be produced by mould. Now the manufacturing technology level of automotive stamping die is relatively backward in domestic, unable to cope with this market very well. The production efficiency can be increased several times and even dozens of times by using of multi-position progressive die, which signified advanced level of stamping die technology. The sheet thickness of automobile parts can be reduced while adopt high strength steel, which is an important way to realize vehicle lightweight. Based on finite element numerical simulation, the virtual simulation can reduce physical stamping trial, shortening the period of mould development. The research subject is supported by High-level Talents of Higher Education of Guangdong Province(No.x2jqN9101140)-"Research on Precise Design Technology of Multi-position Progressive Die of High Strength Steel Automotive Structural Parts", and Production, Teaching&Research Collaborative Project between Guangdong Province and Ministry of Education of China(No.2010B090400094)-"Virtual Manufacturing and Industrial Application of High Strength Steel Multi-position Progressive Die"The automotive soleplate component part researched in this paper is made by the high strength steel and difficult to be deformed. The progressive die stamping technology was studied by means of finite element numerical simulation. The numerical simulation of complete process chain of forward drawing, reverse drawing, bending and reforming involved in progressive die stamping were accomplished. The numerical simulation can forecast the shortcoming in drawing, such as cracking, wrinkling and obtain parameters to the benefit of progressive process.The research results were used for the practical production finally, and qualified soleplate component parts was produced. The main research contents and conclusions of this paper are summarized as follows:(1) The formability of this part was analyzed in detail by the one-step inverse forming analysis method. Then the single blank shape reverse was conducted combined with blank size engineering (BSE) module of Dynaform. To modify the shape of blank according to the key position forming simulation results can make the final stamping part achieve higher precision.(2) The deformation degree of reinforcing rib on the part is too large. The forward and reverse drawing are adopted to reduce thining phenomenon effectively, and to enhance forming quality. The material are stored after the preformation forward drawing. The trimming process is arranged after reverse drawing, and there is an empty position between them to avoid interference. The blanking and bending on different plane of the workpiece realized through changing the angle between workpiece and carrier. Then two bending and blanking process are arranged accordingly.(3) The strip layout with13positions was designed according to technology analysis.The single-row with unilateral carrier and double-row with intermediate carrier layout patterns was compared and analyzed, and the double-row layout with intermediate carrier was finally designed.The results show that the high production efficiency and material utilization of workpiece can be obtained by the double-row layout with intermediate carrier, which is more suitable for the mass production.(4) The localized distortion of strip layout after imported into Dynaform can be eliminated while use HyperMesh to proceed finite element mesh generation. The models are all built in UG. The whole progressive stamping was simulated based on the method of multi-position and multi-process. Especially the forward and reverse drawing of position3and position4, the key forming processes during13positions progressive stamping, were analyzed in detail. The satisfied simulation results was obtained after re-building the finite element model based on the modified shapes of blank and convex hull. The key technologies of numerical simulation during multi-position and multi-process progressive stamping were solved, such as historical information transferred between processes, finite element modeling and mould interference problems.(5) The progressive stamping trial was carried through. The sheet thickness of forward and reverse drawing of practical stamping complete process chain were measured. Comparison between numerical simulation and practical stamping was analyzed. The results are consistent with each other, the maximum relative error is8.4%, and the validity and rationality of using the method of multi-position and multi-process numerical simulation are verified.