Process for producing hollow metal articles

Abstract

The invention concerns a process for producing a metallic hollow body (1), in which a hollow cast part (1′) is produced by metal casting, in which the cast part (1′) is deformed by means of internal high pressure deformation in the hollow body (1). In order to improve the quality of the hollow body (1), the cast part (1′) is so produced, that it has a wall thickness distribution supporting or simplifying the internal high pressure deformation.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention concerns a process for producing metallic hollow bodies of the type set forth in the pre-characterizing portion of the main claim. [0003] 2. Description of the Related Art [0004] DE 10244338A1 discloses a machining operation for hollow cast parts, wherein the cast part is acted upon with high pressure using an internal high pressure deforming tool. By internal high pressure deforming, the cast part is normed, in order to correct any warping produced during casting. [0005] DE10125121A1 discloses an exhaust pipe bender, of which the individual parts are produced using deep drawing techniques. [0006] DE19847876A1 discloses a shock absorber strut carrier or spring stit carrier, produced as a cast part. [0007] U.S. Pat. No. 4,571,969 discloses a process for autofretage of a thick wall hydraulic cylinder by means of internal high pressure deformation. [0008] EP0952067A2 discloses an automobile body c...

AI Technical Summary

Benefits of technology

[0010] The present invention is concerned with the problem of providing, for a manufacturing process of the above-described type, an improved embodiment, which in particular improves the quality of the hollow body produced as a result of the process.

[0013] According to one preferred embodiment, the cast part can, next to the deformation area, in which the cast part is deformed during internal high pressure deformation, exhibit at least one supply or reservoir zone, which exhibits a wall thickness which is greater relative to the adjacent neighboring area of the cast part. During internal high pressure deformation the material can flow out of the reservoir zone into the respective deformation area, whereby in the deformation area, relatively large wall thicknesses can be realized. Similarly, in the deformation area, as a result of the material flowing from the reservoir zone, a relatively strong bending or deforming can be realized.

[0014] In another embodiment, the cast pant can exhibit, adjacent to a deformation area, in which the cast part is deformed by internal high pressure deformation, at least one anchor zone, which is located at an external contour of the cast part and which cooperates during internal high pressure deformation with a matrix or die of an internal high pressure deformation tool for fixing the cast part in the matrix. In this design the cast part can be effectively fixed in the matrix during internal high pressure deformation, which improves the quality of the internal high pressure deformation and in particular, specifically limits the deformation to predetermined deformation areas. The invention here also takes advantage of the possibility of a quasi unrestricted shape for the cast part, in order to simplify or, as the case may be, improve, with a special design of the cast part, the internal high pressure deformation process.

Problems solved by technology

In this mariner, deformations can be carried out during the internal high pressure deformation, which could otherwise not be produced or realized due to reduced wall thickness and the danger of a formation of cracks.

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