Press-forming method of tubular part having cross section of irregular shape, and tubular part having cross section of irregular shape formed by the press-forming method
US8894080B2 · kind B2 · utility
3Cited by
8References
3Claims
0Family size
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Key dates
| Filing date | May 12, 2009 |
| Grant date | Nov 25, 2014 |
| Priority date | — |
| Expiry date | Oct 2, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12299
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of press-forming a tubular part having a cross section of an irregular shape crushes a steel tube between an upper die and a lower die in order to form a V-shaped cross section. When the curvature radius of a tip of the upper die is defined as R1, the curvature radius of a bottom portion of the lower die corresponding to the tip of the upper die is defined as R2, and the wall thickness of the steel tube is defined as t; R1, R2, and t satisfy R1+2t=R2 and 1.5t≦R1≦3t.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.