Press die
US6807838B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 2001 |
| Grant date | Oct 26, 2004 |
| Priority date | — |
| Expiry date | Dec 3, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D11/18
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A press die composed of an upper die having a concave part (with the peripheral surface of the opening of said concave part functioning as a first blank pressing face), a lower die having a convex part (to form the blank into a desired form in cooperation with said concave part), and a blank holder (which has a second blank pressing face), said press die working in such a way that said first blank pressing face and said second blank pressing face hold a blank between them while permitting it to flow into said concave part during pressing, characterized in that at least either of said first blank pressing face and said second blank pressing face has a roughened surface with a plurality of striated projections which are formed in the direction inclined in a range of −25° to +25° (preferably approximately parallel) toward the circumferential direction of the edge of the opening of said concave part.The press die permits the blank to slide easily and hence prevents the blank from decreasing in thickness during press forming.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.