Forging method for a hollow article
US4918969A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1989 |
| Grant date | Apr 24, 1990 |
| Priority date | — |
| Expiry date | Jun 9, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21K21/08
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A forging method comprises the following four steps: a first step of disposing a columnar material into a first die and extruding one end portion of the material with a first punch in a direction opposite to the advancing direction of the first punch, a second step of deepending a first blind hole in a second stepped die with a cavity having large and small internal diameter portions, and extruding the other end portion of the material into the inside of the small internal diameter portion of the cavity with a second punch which has been previously extended thereinto, a third step of fitting the first and second blind holes to third punches while exposing the small outer diameter portion from a third die and pressurizing, by means of a sleeve, only an end face portion of the small outer diameter portion formed with the second blind hole to expand the small outer diameter portion of the material toward an outer periphery, and a fourth step of punching out a blind portion of the material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.