Metal sheet forming process with hydraulic counterpressure
US4472955A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1983 |
| Grant date | Sep 25, 1984 |
| Priority date | — |
| Expiry date | Apr 20, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D22/205
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A punch is pressed on a blankpiece into a die. The die is filled with liquid therein, whereby hydraulic counterpressure is generated by said pressing. The pressed blankpiece is forcibly followed in shape around the punch by hydraulic counterpressure, while part of the hydraulic counterpressure is automatically supplied to an outer circumference of the blankpiece via bypath passage. In case, the blankpiece is a plate, said supplied hydraulic pressure serves as compression force from the outer circumference of the flange to the radius direction. In case, the blankpiece is a product formed by a first drawing, said pressure serves as pressing force toward axial direction of a side wall of the product. When the supplied hydraulic pressure flows out from a space between the punch and a blank holder, the liquid serves as lubrication on an upper and lower surfaces of the blankpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.