EP 0347369 A3 19901017 - METHOD AND APPARATUS FOR HYDRAULICALLY ENLARGING HOLLOW PROFILES
Title (en)
METHOD AND APPARATUS FOR HYDRAULICALLY ENLARGING HOLLOW PROFILES
Publication
Application
Priority
DE 3820952 A 19880616
Abstract (en)
[origin: EP0347369A2] The invention relates to a method for enlarging metal, especially steel, hollow profiles essentially open at the end faces to a shape which is predetermined by a divided outer die surrounding the hollow profile, the end faces being sealed by means of sealing heads and a hydraulic internal pressure being applied inside the hollow profile for the purpose of deformation. In order to specify a method for hydraulically enlarging metal hollow profiles which can be carried out as simply as possible and in which, in particular, the hollow profile is sealed off without great outlay in terms of equipment, it is proposed that the rigid part of the sealing heads should in each case be sealed off from the hollow profile via a flexible hollow sealing ring by subjecting the interior of the sealing ring to a pressure P1 which is at all times greater than the particular pressure P2 used for deforming the hollow profile, and bringing it to rest against the inner or outer surface of the hollow profile, the enlargement of the hollow profile in the region of the sealing ring being limited from the outside to within the capability of the sealing ring to adapt to the surface of the hollow profile. <IMAGE>
IPC 1-7
IPC 8 full level
B21D 26/02 (2011.01); B21D 26/045 (2011.01)
CPC (source: EP KR US)
B21C 37/00 (2013.01 - KR); B21D 26/033 (2013.01 - KR); B21D 26/045 (2013.01 - EP KR US); B30B 5/02 (2013.01 - EP); B30B 7/04 (2013.01 - EP)
Citation (search report)
- [X] US 3625040 A 19711207 - GAIN WILLIAM J DE
- [X] GB 650333 A 19510221 - ROBERTSHAW FULTON CONTROLS CO
- [X] US 1930745 A 19331017 - FISHER JAMES P
- [A] FR 1245164 A 19601104
- [A] DE 1158934 B 19631212 - BALDWIN LIMA HAMILTON CORP
Designated contracting state (EPC)
BE CH DE ES FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0347369 A2 19891220; EP 0347369 A3 19901017; DE 3820952 A1 19891221; DE 3820952 C2 19910124; JP H0284219 A 19900326; KR 900000138 A 19900130; US 4951492 A 19900828
DOCDB simple family (application)
EP 89730141 A 19890612; DE 3820952 A 19880616; JP 15201089 A 19890614; KR 890008417 A 19890616; US 36718789 A 19890615