Title:
MANUFACTURE OF THIN HEMISPHERE
Document Type and Number:
Japanese Patent JP3293962
Kind Code:
B2
Abstract:
PURPOSE: To enable a large scale formation without using a large scale pressing device by providing a fitting groove on the outer peripheral part of a lower die having the same material as a forming blank, seal-welding the lower die and the outer peripheral edge of the forming blank and gas-pressure-forming.
CONSTITUTION: The lower die 1 and the outer peripheral edge of the forming blank 3 are seal-welded. After executing the seal-welding, the surface of the forming blank 3 is roughened so as to fit to the fitting groove in the lower die 1. An upper die 2 is laid on the forming blank and set so as to match to the fitting groove. These dies and the forming blank are set into an electric furnace 6 and heated to a prescribed temp. and forming gas is supplied into a gap between the forming blank 3 and the lower die 1 from a gas piping 4. The forming blank 3 is gradually bulged upward till a hemisphere shape in the upper mold 2 and becomes the hemisphere forming body. The durability of the die can be raised because the large force with a press is not applied.
Inventors:
Shizuo Kawanami
Ryoji Kishikawa
Toshiaki Nishio
Ryoji Kishikawa
Toshiaki Nishio
Application Number:
JP18131593A
Publication Date:
June 17, 2002
Filing Date:
July 22, 1993
Export Citation:
Assignee:
MITSUBISHI HEAVY INDUSTRIES,LTD.
International Classes:
B21D26/021; B21D26/029; B21D26/055; B21D51/08; B21D51/18; (IPC1-7): B21D26/02; B21D51/08; B21D51/18
Domestic Patent References:
| JP6293034A | ||||
| JP1241330A | ||||
| JP550153A | ||||
| JP6304673A | ||||
| JP61273222A | ||||
| JP5329535A | ||||
| JP542338A | ||||
| JP62179822A | ||||
| JP6297723A | ||||
| JP62101630U |
Attorney, Agent or Firm:
Akira Uchida (2 outside)