Research On Surface Tribological Behavior Control And Engineering Application Of Automotive Muffler Half Shell Mould

During the drawing process,the friction characteristics of the mold surface are closely related to the material flow behavior of the workpiece.Our research group proposes the laser composite texture technology of the mold surface,by processing the convex body friction increasing and the concave body friction reducing texture,to realize the active control and optimization of the friction characteristics of the complex mold surface.In this paper,the automobile muffler half-shell mold is the research object,combined with numerical simulation analysis and forming experiment,aiming at reducing the maximum thinning rate of the formed part and improving the uniformity of the plate thickness,the zoning optimization design of the friction coefficient of the mold surface is carried out.Fristly,the theoretical analysis of the stress-strain relationship in the sheet metal stamping process is carried out,and the main forming characteristics,forming defects and solutions of automobile panels are introduced.In view of the complexity and diversity of the structural features of automotive panel molds,it is proposed to use the "decomposition-comprehensive method" to classify and summarize them,and specifically analyze the influence of different structural feature elements on the deep drawing formability,which lays a theoretical foundation for the judgment and division of the friction sensitive area on the mold surface.Secondly,the finite element software of ABAQUS is used to numerically simulate the drawing and forming process of the automobile muffler half shell.According to the preliminary simulation results,an optimized path is defined for the most severely wrinkled and thinned areas of the formed part.Divide the mold surface area,and find the area where mold surface friction has a greater influence on the thickness of the formed part through single factor analysis.With the goal of reducing the maximum thinning rate of the formed part and improving the uniformity of the plate thickness,the friction coefficient of the key area of the mold is optimized.After optimization,the maximum thinning rate of the formed part is reduced by 13.03%,and the variation of plate thickness is reduced by 6.68%.Thirdly,using ROBOGUIDE software to simulate and test the manufacturing process of laser micro bulges of the FANUC robot.First,select the robot model:M-10 i A/8L,set up a simulation working environment,set and calibrate the TCP(tool coordinate system origin)point of the laser head.Then,establish the appropriate user coordinate system and tool coordinate system,and complete the industrial robot I/O signal configuration.Finally,a virtual teaching device is used to write a robot laser texturing array processing simulation program and verify it in practice.Finally,according to the simulation and optimization results above,laser texturing is performed on the friction-sensitive area h on the surface of the automobile muffler half-shell mold.The laser texturing process test and analysis of SKD11 die steel were carried out to determine the laser process parameters of the optimal texturing morphology of the mold surface processing.The texture processing and forming test of the automobile muffler half shell mold are carried out,and compared with the original mold stamping parts.The test results show that the residual stress distribution of the automobile muffler half shell has been significantly improved.Compared with the untextured mold deep-drawn parts,the maximum thinning rate of the texturized mold deep-drawn parts is reduced by 23.53%,and the plate thickness uniformity is improved by 13.24%.