Research On Key Technology Of Automatic Design For Trimming And Flanging Inserts Based On CATIA Platform

The massive work of design of trimming and flanging die inserts for automobile panel is extremely time-consuming,and affected by the marked high error rate,causing low efficiency.In order to solve these problems,some manufacturers have developed some design system custom to trimming and flanging die inserts,to optimize the design process.However there are still a series of issues in the application,such as cumbersome operation,low degree of automation,poor adaptability and stability.Especially when dealing with complex three-dimensional trimming and flanging curves,it needs a lot of manual processing on the dimensional curves,which reduces the efficiency and quality of mold design.Therefore,it has important theoretical research and practical application value to study the stability and high degree of automation.In this paper,the structure variety of the die block of the trimming and flanging inserts is analyzed in detail,then curve process and surface creation methods also are studied to improve the low efficiency of manual process.Combined with the project of “CATIA mold design assistant tools”,the block structure and automated design process are detailed designed taking advantage of modular and parametric design,and the corresponding system is achieved.In order to solve the problem of three-dimensional trimming curve in space offset,a offset method is proposed,which could handle the offset in the stamping direction and the datum plane.In the stamping direction,the 3D offset is transformed into a two-dimensional operation by using the offset of the curve on the supporting surface.On the datum plane,the rolling-circle method is used to simulate the characteristic of the circle rolling on the curve side,thus the fitting of the center trajectory achieves the 3D offset solving the problem of high error rate of CATIA manual operation.To fix the issue that the smoothing of trimming curve cause the non-fitting between the edge of the blade and the trim design,a specified smooth scheme is proposed,that is through the fitting of the tangent point in the rolling-circle method,which meets the design requirements.In order to solve the problem of poor quality of edge design and wave edge design,a segment-based method of creating edge surface is proposed.The method divides the points into multiple segments according to the angle change of the broken line contour after the disc is separated,and correspondingly divides the curve into multi-segment,so that the whole creation of the surface is transformed into local creation,which avoid the high requirement raised by the bridging method,making the surface bridge success.Then the integration of local bridging surface can be a smooth blade surface,solving the wrinkles or even failure when creating surface by CATIA general surface method.Finally,the design system of trimming and flanging insert is designed and implemented.A large number of examples prove that the system can automatically create a variety of trimming and flanging inserts,and verity that the system has a high degree of automation,can improve design efficiency,while reducing design difficulty and increase stability.Because of the simple process and short design cycle,the system is widely used by the cooperative enterprises,and achieved good practical results.