EP 3225321 A4 20171227 - METHOD FOR MANUFACTURING STEEL PIPE AND PRESS MOLD USED IN SAID METHOD
Title (en)
METHOD FOR MANUFACTURING STEEL PIPE AND PRESS MOLD USED IN SAID METHOD
Title (de)
VERFAHREN ZUR HERSTELLUNG EINES STAHLROHRS UND IN DIESEM VERFAHREN VERWENDETE PRESSFORM
Title (fr)
PROCÉDÉ DE FABRICATION DE TUYAU EN ACIER ET MOULE DE PRESSE UTILISÉ DANS LEDIT PROCÉDÉ
Publication
Application
Priority
- JP 2014237608 A 20141125
- JP 2015081818 W 20151112
Abstract (en)
[origin: EP3225321A1] Provided are a method of producing a steel pipe by performing bending on a plate material, and a press die used in the method. A method of producing a steel pipe in which a plate material having an end bending portion is subjected to at least one bending along its widthwise direction to form a preformed body having a U-shaped cross-section, an open pipe with a gap portion in a longitudinal direction is formed by adding a bending force to the preformed body to press the preformed body, and end surfaces of the gap portion of the open pipe are butt-joined to each other to form a steel pipe, the method including: providing a lightly-bent portion to which very slight curvature is applied as compared to other regions, or providing a non-bent portion in which the bending is omitted, in at least a part of the plate material, in performing bending on the plate material; and applying the bending force to a part spaced apart at least from the center of the lightly-bent portion or the non-bent portion in a width end portion direction of the plate material by amount of W/4 (where, W is a width size of the plate material), without constraining the lightly-bent portion or the non-bent portion, in pressing the preformed body into the open pipe.
IPC 8 full level
B21D 5/01 (2006.01)
CPC (source: EP KR RU)
B21D 5/01 (2013.01 - EP KR RU); B21D 5/015 (2013.01 - EP)
Citation (search report)
- [XDI] JP 2012250285 A 20121220 - SMS MEER GMBH
- [XAI] JP S53112260 A 19780930 - NIPPON KOKAN KK
- See also references of WO 2016084607A1
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
EP 3225321 A1 20171004; EP 3225321 A4 20171227; EP 3225321 B1 20230830; BR 112017010436 A2 20171226; BR 112017010436 B1 20211026; CA 2967914 A1 20160602; CA 2967914 C 20200324; CN 107000012 A 20170801; CN 107000012 B 20190827; JP 6015997 B1 20161026; JP WO2016084607 A1 20170427; KR 20170070155 A 20170621; RU 2663674 C1 20180808; WO 2016084607 A1 20160602
DOCDB simple family (application)
EP 15863977 A 20151112; BR 112017010436 A 20151112; CA 2967914 A 20151112; CN 201580063275 A 20151112; JP 2015081818 W 20151112; JP 2016518784 A 20151112; KR 20177012910 A 20151112; RU 2017118946 A 20151112