METHOD AND BENDING TOOL FOR BENDING PIPES OVER A MANDREL WITH AN ADJUSTABLE MANDREL RETAINER MEANS BEADING TOOL AND ROTATING BENDING TOOL WITH SUCH A BEADING TOOL

Title:

METHOD AND BENDING TOOL FOR BENDING PIPES OVER A MANDREL WITH AN ADJUSTABLE MANDREL RETAINER MEANS BEADING TOOL AND ROTATING BENDING TOOL WITH SUCH A BEADING TOOL

Document Type and Number:

WIPO Patent Application WO/2010/025883

Kind Code:

A3

Abstract:

The invention relates to a method and a device for bending pipes (3) over a mandrel (6), in particular pipes having thin walls, on a rotary draw bending tool (1), which comprises a bending template (2), a slide rail (4) which is arranged above the pipe and which holds the pipe and the mandrel in position, and at least one upper, outer clamping jaw (7), which, rotating by a bending angle, presses the pipe (3) against the bending template (2). The invention also relates to a bending tool (1) and to a beading tool suitable for the method or for the bending tool. According to the method, in order to prevent the formation of folds, a tensile force applied to the pipe (3) during the bending process and therefore the trailing of pipe material in the bending zone on the inside (3b) of the pipe bend (3a) are retarded by at least one mandrel retaining means which can be placed against the mandrel shaft, wherein tensile stress is introduced at the pipe bend inner radius and the critical compressive stress leading to fold formation is no longer met.

Inventors:

ENGEL BERND (DE)
CORDES STEFAN (DE)
MATHES CHRISTIAN (DE)

Application Number:

PCT/EP2009/006301

Publication Date:

June 17, 2010

Filing Date:

September 01, 2009

Export Citation:

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Assignee:

UNI SIEGEN (DE)
ENGEL BERND (DE)
CORDES STEFAN (DE)
MATHES CHRISTIAN (DE)

International Classes:

B21D7/02; B21D7/022; B21D9/07

Domestic Patent References:

WO2009083609A2

2009-07-09

Foreign References:

US20040011106A1	2004-01-22
EP1086760A2	2001-03-28
US20050150268A1	2005-07-14
US4009601A	1977-03-01
JP2002263738A	2002-09-17
JPS5739037A	1982-03-04
US1238941A	1917-09-04
DE9107234U1	1992-01-23
US5950482A	1999-09-14
DE29708498U1	1998-05-07
US6164113A	2000-12-26

Attorney, Agent or Firm:

GROSSE, Wolf-Dietrich (Gihske Grosse, Klüppe, Hammerstrasse 3 Siegen, DE)

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