BENDING METHOD FOR PIPE MATERIAL

Title:

BENDING METHOD FOR PIPE MATERIAL

Document Type and Number:

WIPO Patent Application WO/2000/043143

Kind Code:

A1

Abstract:

A bending method for pipe material using a conventional device such as press device, wherein, in order to prevent wall thinning and cracks, one side of a cylindrical pipe material (1) is firmly held by a first clamp (2) with the other side loosely held by a second clamp (3). The clamp (2) is moved downward in the drawing with respect to the clamp (3), with an axially pressing force applied to the pipe material (1) at the opposite ends thereof. The pipe material (1) is plastic-deformed by being guided by a 1/4 spherical surface (4a) of a core (4) and a 1/4 spherical surface (5a) of a core (5) to form linear portions at two bending portions and at an intermediate portion therebetween.

Inventors:

SEKIDO YUTAKA (JP)

Application Number:

PCT/JP2000/000252

Publication Date:

July 27, 2000

Filing Date:

January 20, 2000

Export Citation:

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Assignee:

SANGO CO LTD (JP)
SEKIDO YUTAKA (JP)

International Classes:

B21D7/06; B21D9/04; B21D9/05; (IPC1-7): B21D9/04; B21D9/05

Foreign References:

US5483809A	1996-01-16
JPS63192519A	1988-08-09
JPS5510328A	1980-01-24
JPS315068B1

Other References: