Method and apparatus for manufacturing a hollow body from a tubular blank by internal high-pressure shaping
US6112567A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 1999 |
| Grant date | Sep 5, 2000 |
| Priority date | — |
| Expiry date | Mar 25, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D26/033
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The invention relates to a method for shaping a hollow body from a tubular blank inserted into a shaping tool that can be opened and closed, by internal high pressure introduced into the interior of the blank. The cross section of the blank, prior to the internal high-pressure shaping, can be changed and pre-shaped from a round or rectangular shape, depending on the workpiece. In order to be able to produce workpieces with a circumference that varies considerably over the length without overstretching the material, according to the invention, for pre-shaping the blank, a dent that differs in depth over its length is formed in the blank. During the internal high-pressure shaping of the pre-shaped blank to form a hollow body, a U-shaped fold is formed from the dent that projects into the interior of the hollow body, with the walls of the fold abutting one another directly and merging at the periphery with the circumferential wall of the hollow body. The two walls of the fold are permanently connected to one another and the two walls of the fold are preferably permanently welded together in the vicinity of the circumference of the hollow body.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.