Title:
BENT PIPE AND ITS MANUFACTURE
Document Type and Number:
Japanese Patent JP3373245
Kind Code:
B2
Abstract:
PURPOSE: To provide a bent pipe, in which the radius of curvature is the pipe diameter or smaller and the curvature is uniform and the roundness in the cross section of a passage is high, in a low cost and its manufacturing method.
CONSTITUTION: By bending the pipe 2, a bent pipe intermediate body 2' provided with a first and a second straight pipe parts 2a, 2b and a bent part 2c is manufactured. Successively, by using a first punch 8 and a first core metal 9, sprue working is applied to the first straight pipe part 2a side to form a flange part 11, and also the half part of the bent part 2c at the first straight pipe part side is formed. Successively, by using a second punch 13 and a second core metal 14, bulging work is applied to the second straight pipe part 2b to form a bead part 15, and also the half part of the bent part 2c at the second straight pipe part side is formed into the bent pipe part 2d having the radius of curvature in the pipe diameter or smaller. In such a way, the bent pipe P, in which the radius of curvature is the pipe diameter or smaller and the curvature is almost uniform and the roundness in the cross section of the passage is high, is manufactured from the simple straight pipe 2 at a low cost.
Inventors:
Arata Ohnishi
Mitsuhiro Okahara
Mitsuhiro Okahara
Application Number:
JP5560893A
Publication Date:
February 04, 2003
Filing Date:
March 16, 1993
Export Citation:
Assignee:
Matsumoto Heavy Industries Co., Ltd.
Mazda Corporation Inc
Mazda Corporation Inc
International Classes:
B21D51/16; B21D3/14; B21D7/00; F16L43/00; (IPC1-7): B21D51/16; B21D3/14; B21D7/00; F16L43/00
Domestic Patent References:
| JP2253088A | ||||
| JP54157181A | ||||
| JP56133192U | ||||
| JP121892U |
Attorney, Agent or Firm:
Aoyama Ryo (1 person outside)