Method and die for back-pressure deep drawing of metal plate

Abstract

Disclosed is a die for deep drawing of a metal plate. The lower end of a concave die of the die is fixed onto a worktable of a press, a back-pressure head is disposed on the lower portion of a cavity of the concave die, the shape of the back-pressure head corresponds to that of a formed part, a blank holder is disposed on the concave die, the upper portion of the blank holder is a feeding barrel for containing solid granular media, and a punch is disposed on the granular media in the feeding barrel. During deep drawing, the metal plate is placed on the upper surface of the concave die, the lower surface of the plate simultaneously contacts with the back-pressure head, bland pressing force is applied to the blank holder, the solid granular media are added into the barrel, the punch moves downwards so that the solid granular media generate forming pressure, back pressure is simultaneously applied to the back-pressure head below the metal plate, the back pressure is lower than the pressure of the punch, and the process is carried out until the plate deforms to have a required forming height; and then the punch and the blank holder return, the back-pressure head is jacked up, and a workpiece is unloaded. The die is simple in structure, the wall thickness difference of the formed part is obviously reduced, the plate part can be deeply drawn at one step, sealing is omitted, pollution is prevented, and the granular media can be recycled.

Description

technical field [0001] The invention relates to a forming method and a mold of a metal plate. Background technique [0002] Although the ordinary rigid die deep drawing method for metal sheets is widely used, it needs to be drawn many times for the sheet metal forming with a large aspect ratio, the cost of the mold is high, and the dimensional accuracy and surface roughness of the drawn parts are not high. Local thinning makes it difficult to form parts with complex shapes, and cannot adapt to the production of multiple varieties and small batches. [0003] At present, in view of the deficiency of traditional punch and concave die deep drawing for forming low plasticity and large deformation sheet metal parts, sheet metal soft die forming is proposed. The soft mold forming of the plate is a process of using a force-transmitting medium as a punch (concave) and then using a rigid die (convex) to shape the plate under the action of a pressure-transmitting medium. Now there ha...

AI Technical Summary

Problems solved by technology

However, these techniques have their own shortcomings

[0004] In the hydroforming of sheet metal, sealing rings must be used to force the liquid to be sealed, which restricts the flow of sheet metal and is not conducive to the forming of sheet metal

Moreover, in the forming process, once the plate becomes unstable and wrinkled, the oil splashes and pollutes the environment.

In addition, in hydroforming, a complex control system must be equipped, and the mold structure is complex

[0005] In order to solve the problem of difficult sealing in hydroforming, the forming of viscous medium has made up for the shortcomings of hydroforming to a certain extent, but the forming of viscous medium still needs to be sealed, and the mold also needs to be equipped with a separate control system. The workpiece is cleaned after forming. difficulty

These shortcomings of viscous media forming also limit the application of viscous media forming process

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