Method for producing a peripherally closed hollow profield element

Abstract

The invention relates to a method for producing a peripherally closed hollow profiled element by means of internal high-pressure forming, a hollow elongated blank (5) being inserted into an internal high-pressure forming tool (1), and the blank (5) located completely inside the forming tool (1) after the insertion being compressed in a region lying between its ends (9, 10) during the closing operation of the forming tool (1), after which the compressed blank (5) is expanded into the final shape of the hollow profiled element by means of fluidic internal high pressure. In order to permit reliable production of the hollow profiled element even during pronounced compression deformations of the blank (5) of the hollow profiled element, which are produced during the closing of the forming tool (1), it is proposed that the ends (9, 10) of the blank (5) be trimmed before the compression operation, with a respective beveled front face (12, 13) being formed, and that the trimming contour of the ends (9, 10) and the beveling angle (α) be selected in such a way that the ends (9, 10) are deformed by means of the compression operation in such a way that their front faces (12, 13) have an essentially plane form and assume a position which is as perpendicular as possible to the longitudinal extent of the blank (5).

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a national stage of PCT / EP2004 / 004301 filed Apr. 23, 2004 and based upon DE 103 23 738.0 filed May 24, 2003 under the International Convention.BACKGROUND OF THE INVENTION [0002] 1. Field of the invention [0003] The invention relates to a method for producing a peripherally closed hollow profiled element. [0004] 2. Related Art of the invention [0005] A method of the generic type has been disclosed by WO 98 / 43758 A1. In this case, a blank of a hollow profiled element of uniform cross section is inserted into an internal high-pressure forming tool, the die cavity of which has a reduced cross section relative to the blank in the region between its ends. As a result, the inserted blank of the hollow profiled element is compressed in this region during the closing operation of the forming tool. However, the drawing-in, resulting from this, of the blank of the hollow profiled element manifests itself in inclination or deform...

AI Technical Summary

Benefits of technology

[0006] The object of the invention is to develop a method of the generic type to the effect that reliable production of the hollow profiled element is made possible even during pronounced compression deformations of the blank of the hollow profiled element, which result during the closing of the forming tool.

Problems solved by technology

On account of the end contour changed by the compression and on account of the tilting of the front face, the axial plungers provided with a conical sealing region and subsequently docking with the ends of the blank can only seal off the blank inadequately relative to the internal high pressure subsequently to be produced.

The result of this is that the operation subsequently taking place for expanding the blank by means of the fluidic internal high pressure is not completely reliable and thus the hollow profiled element cannot be produced as desired.

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