EP 0312808 A3 19891018 - PRESS FOR DRAWING SHEET COMPONENTS
Title (en)
PRESS FOR DRAWING SHEET COMPONENTS
Publication
Application
Priority
DE 3735581 A 19871021
Abstract (en)
[origin: EP0312808A2] The invention relates to a press for drawing sheet components, in which the hold-down force during the drawing operation is applied to the hold down of the tool by a drawing apparatus of the forming machine. In order to be able to set the hold-down force individually, preferably zone by zone, with accuracy of reproduction and low inertia and hold it at the preset value, the drawing apparatus (es) is (are) designed in such a way that a hydraulically controlled die cushion is used during the drawing operation. A hydraulic hold-down force control is provided for the (each) die cushion of a press. Via a pressure or force sensor assigned to each die cushion, it is possible to measure the associated hold-down force. Via a forward path formed by a controller and a throttle valve under electrohydraulic pilot control, the force-determining pressure space of the die cushion can in each case be adjusted individually to the required pressure. This forward path operates with a low inertia and substantially without hysteresis, allowing the desired value for the hold-down force to be changed in accordance with a recurring functional sequence, even during a pressing cycle. <IMAGE>
IPC 1-7
IPC 8 full level
B21D 24/04 (2006.01); B21D 22/26 (2006.01); B21D 24/08 (2006.01); B21D 24/10 (2006.01); B21D 24/14 (2006.01); B30B 15/22 (2006.01); B30B 15/28 (2006.01)
CPC (source: EP)
B21D 22/26 (2013.01); B21D 24/14 (2013.01)
Citation (search report)
- [AD] DE 2407864 B2 19760219
- [A] EP 0173755 A1 19860312 - SCHULER GMBH L [DE]
- [A] DE 2609916 A1 19770915 - ETSCHEID OHG HERMANN
- [A] DE 3406526 A1 19850912 - MUELLER WEINGARTEN MASCHF [DE]
- [A] US 4635466 A 19870113 - SEKI SEIJI [JP], et al
- [A] PATENT ABSTRACTS OF JAPAN
Designated contracting state (EPC)
DE ES FR GB IT SE
DOCDB simple family (publication)
DE 3735581 C1 19880511; DD 283086 A5 19901003; EP 0312808 A2 19890426; EP 0312808 A3 19891018; JP H01127118 A 19890519
DOCDB simple family (application)
DE 3735581 A 19871021; DD 32086788 A 19881018; EP 88115855 A 19880927; JP 26426488 A 19881021