Method for accurately controlling trimming line of turned edge under complex curved surface

Abstract

The invention discloses a method for accurately controlling a trimming line of a turned edge under a complex curved surface. The method comprises the following steps of unfolding an edge-turned flange portion to a complex three-dimensional curved surface in an inverse manner according to the shape of a stamping part so as to obtain an approximate trimming line; trimming a plate which is formed and simulated by a previous working procedure to obtain an edge-turned blank; simulating forming of a turned edge by using a finite element incremental method; comparing a simulating result to an ideal shape; measuring deviation epsilon between grid nodes at the border of the turned edge and an ideal workpiece; performing proportional compensation on the nodes along the normal direction of the trimming line according to the comparison deviation epsilon; correcting the trimming line; and trimming the turned edge again and simulating forming of the turned edge again by using the corrected trimming line until the deviation of the simulating result is controlled within a set value delta. By the method, the trimming line of the turned edge can be accurately determined, the trimming line of the turned edge under the complex three-dimensional curved surface can be accurate and reliable, the quality of forming of the turned edge is effectively improved, and the mold manufacturing and producing cost is reduced.

Description

technical field [0001] The invention specifically relates to an accurate determination of a flanging and trimming line, in particular to a method for accurately determining a flanging and trimming line of a complex curved surface combined with three-dimensional space multi-curved surfaces, and belongs to the field of plastic forming of metal sheets. Background technique [0002] The design of the flanging and trimming line directly affects the quality of stamping forming. By accurately determining the flanging and trimming line, the shape of the flange after flanging can be guaranteed to meet the size requirements, and the occurrence of forming defects during flanging can be effectively reduced. Flange forming is a very complicated physical process. In production practice, in order to achieve the dimensional accuracy of the flange, it is often necessary to repeatedly correct the inserts of the trimming mold, which not only causes waste of materials and manpower, but also affe...

AI Technical Summary

Problems solved by technology

[0005] For workpieces with complex shapes and flanging under complex curved surfaces, usually multiple forming processes such as deep drawing are required before flanging, so it is necessary to consider the influence of the forming process before flanging on the formability of the sheet metal, and be able to It is relatively fast and accurate to determine the trimming line of the flanging process, but the current finite element analysis commercial software and methods have certain limitations in the design of the trimming line of this type of flanging, and it is difficult to obtain satisfactory results

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