| The die for automobile panel has the characteristics of large size,complex surface shape and high processing accuracy,and has special hardness requirements in local position.Therefore,it is necessary to use different hardness curved surface inserts according to the force on different parts of the die and the complex shape characteristics.Ball-end milling cutter is the most commonly used tool in automobile panel surface splicing die processing.Under the special processing conditions of multi-hardness splicing and curved surface,if the strength of the ball-end milling cutter is insufficient,cracks or micro-cracks will occur in the key parts of the cutter edge,which significantly reduces the sharpness of the cutter,resulting in tool breakage loss,which not only leads to the increase of processing costs,but also makes the die table.The quality of flour deteriorated.Based on the above problems,this paper mainly focuses on the structural optimization of ball-end milling cutters used in processing convex surface splicing dies(Cr12MoV hardened steel,high and low hardness 60 HRC and 45 HRC respectively).The main contents are as follows:Firstly,based on ABAQUS software,rapid tool change and rapid modeling of splicing die milling simulation process are redeveloped to solve the problems of low efficiency and low precision caused by manual repeated modeling.This part lays the foundation for subsequent tool optimization finite element simulation.Secondly,the processing characteristics and tool structure of the convex surface splicing die are studied.The processing characteristics of the convex surface splicing die are studied from two aspects: convex surface splicing and multi-hardness splicing.In the part of tool structure analysis,firstly,the tool structure is numerically analyzed by numerical method,and then the influence of different tool angles on the milling process of convex surface splicing die is analyzed,which provides a theoretical basis for tool optimization finite element simulation.Then,the simulation of the splicing die for different structure cutter milling convex surface is carried out,and the thermo-mechanical coupling model of milling process is established by using ABAQUS finite element simulation software.The simulation results of milling force and tool temperature during milling process are extracted to provide optimization data for subsequent tool structure optimization.Finally,the genetic algorithm is used to optimize the tool structure,and the optimized tool is milled by a four-axis machining center.The experimental results of the optimized tool are compared with those of traditional tool milling,and the effectiveness of the optimization is verified.The research results provide strong support for improving the processing quality of convex surface splicing die and reducing the processing cost. |
