Global Patent Index - EP 0773076 B1

EP 0773076 B1 2000-04-05 - Apparatus for controlling the pressure in hydraulic cushion devices of presses

Title (en)

Apparatus for controlling the pressure in hydraulic cushion devices of presses

Title (de)

Einrichtung zur Steuerung und Regelung des Druckes in hydraulischen Ziehkissen von Pressen

Title (fr)

Dispositif de commande de la pression dans des serre-flans hydrauliques des presses à emboutir

Publication

EP 0773076 B1 (DE)

Application

EP 96117676 A

Priority

DE 19541693 A

Abstract (en)

[origin: EP0773076A1] The device has a cushion plate (8) guided in the press table (6) which interacts via a pressure bolt (7) with the sheet holder (4) and also interacts with a controllable central cylinder and at least one draw cushion cylinder (11), or the cylinder's piston rod directly interacts with sheet holder. The oil in the cylinder chamber communicates with a biassed tank (130) via a line (28). A proportional valve in the line is subjected to a counter pressure compensated by mass forces acting on the piston. The line (28) between the cylinder chamber and valve (12) is connected to the tank (13) so that a non-return valve (18), a controlled switching valve (19), a pressure source (20), further non-return valve (21) and pump are connected in series. The piston rod is limited by a fixed or adjustable stop (29) and the proportional valve is controlled by a force regulator (23).

IPC 1-7 (main, further and additional classification)

B21D 24/14

IPC 8 full level (invention and additional information)

B21D 24/14 (2006.01)

CPC (invention and additional information)

B21D 24/14 (2013.01)

Designated contracting state (EPC)

DE ES FR GB IT SE

DOCDB simple family

EP 0773076 A1 19970514; EP 0773076 B1 20000405; DE 19541693 A1 19970515; ES 2145362 T3 20000701