FEM Analysis Research On Convex Surface Splicing Mold Milling Process

The rapid development of automobile manufacturing industry has made cars popular among the masses,and the demand for the appearance of cars is becoming higher and higher.Every year automobile manufacturer launch massive new product that in order to beauty appearance,for the purpose of this requires taking automobile covering parts mold as basic equipment.This is greater challenge that ensure the quality of surface in dealing with the complex mold surface,convex surface,concave surface,hardness splicing,grooves.Convex surface,multi-hardness splicing surface is a typical type of automobile covering parts surface.In the process of processing due to the high hardness of the material,multi-hardness splicing and other surface features resulting in splicing joints so extremely unstable load of tool that extremely easy to wear and tear on the surface quality has been affected.With the development of computer technology,using finite element software to simulate cutting machining has become an important auxiliary method.First,in this paper,a tool position system is established in the process of milling the convex surface,and the characteristics of the tool-workpiece contact and the parameters of the cutting layer are described.The influence mechanism of curvature and front rake on milling force in milling process provides theoretical basis for milling force analysis in multi hardness stitching milling process of convex surface.The influence of the angle and curvature on the milling force of the milling process is preliminarily simulated by the simulation method.Then,the finite element simulation software based on ABAQUS/Cae6.14,through the quasi-static test,Hopkinson pressure bar test fitted constitutive parameters,and then input software to establish a three-dimensional finite element model of convex surface multihardness splicing milling process based on finite element simulation technology.In the tool complex trajectory setting,the three-dimensional free curve trajectory is defined by the amplitude curve.The local refinement of the mesh of the cutting edge of a ball end milling cutter and the appropriate iterative analysis algorithm are all sufficient conditions to ensure the convergence of the simulation calculation in the milling process.After the post-processing of the model,the stress field distribution in the milling process of the convex surface splicing die is obtained,and the three-dimensional temperature field of the cutting heat on the downhill slope joint is analyzed.Finally,the effect of milling force mutation at different hardness stitching joints under different milling parameters is simulated.Finally,in four-axis machining center to carry out milling experiments and Swiss KISTLER(Kistler)rotary dynamometer to detect the milling force.Milling experiment is done that milling force of splicing gap under different milling parameters was measured and the milling force in three directions under a pass path was analyzed.The simulation value is compared with the experimental value to analyze the reason of the error.The research results provide a foundation for the establishment of the simulation model of the multi-hardness splicing process in the convex curved surface,and provide the ancillary support for the optimization of milling parameters and the design of the tool structure.