Annular electromagnetic pulse progressive reverse drawing forming method and device for metal sheet

Abstract

The invention provides a metal plate annular electromagnetic pulse progressive reverse drawing forming method. The method includes the steps that a to-be-formed plate is placed between a female die and a male die; the periphery of the female die is provided with a clamping plate, and the periphery of the male die is provided with a supporting frame; pre-forming force is exerted on the to-be-formed plate; electromagnetic force is exerted to push the to-be-formed plate and the clamping plate downwards; electromagnetic force is exerted on the periphery of the to-be-formed plate, and the to-be-formed plate is pushed horizontally towards the center of the female die, so that the to-be-formed plate flows into the female die and reverse drawing forming is achieved; lower pressure is exerted to drive the female die to move downwards, and the to-be-formed plate at the bottom of the female die is squeezed into a gap between the female die and the male die, so that reverse drawing forming of the plate is achieved; reverse drawing and electromagnetic pulse drawing are repeatedly carried out on the female die and the male die until reverse drawing forming is finished. According to the method, forming limits can be substantially increased, and the forming depth of a cylindrical element is increased. The invention further provides a metal plate annular electromagnetic pulse progressive reverse drawing forming device.

Description

technical field

[0001] The invention belongs to the field of plastic forming of materials, and in particular relates to a ring-shaped electromagnetic pulse progressive reverse drawing forming method and device for metal plates. Background technique

[0002] In the traditional sheet metal deep drawing forming process, in order to avoid the wrinkling of the material, it is necessary to use a blank holder to assist in forming. Such as figure 1 Shown is the stress-strain state of the formed sheet during conventional deep drawing. The flange area is subjected to radial tensile stress and tangential (circumferential) compressive stress, and produces elongation and compression deformation in the radial and tangential directions respectively. The thickness of the plate increases slightly, and the thickness at the outer edge of the flange increases the most. At the rounded corner of the die, in addition to being drawn radially, the material also undergoes plastic bending to reduce ...

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