Title:
HYDRAULIC CONTROL ASSEMBLY COMPRISING A DIRECTIONAL CONTROL VALVE FOR CONTROLLING THE DIRECTION AND SPEED OF A SINGLE-ACTION HYDRAULIC CONSUMER
Document Type and Number:
WIPO Patent Application WO2002090778
Kind Code:
A3
Abstract:
The aim of the invention is to improve a hydraulic control assembly comprising a directional control valve that can be proportionally adjusted, in such a way that even for a single-action hydraulic cylinder a significant increase in the lowering speed of the hydraulic consumer is prevented as the load pressure accumulates, in a simple manner. To achieve this, a measuring piston (82) can be subjected to a pressure prevailing in a first consumer chamber (38) during a displacement of a control piston (32) in the second direction. During the lowering operation, the load pressure prevailing in the first consumer chamber thus impinges on the measuring piston. The compensatory force thus created increases with the accumulating load pressure and displaces the control piston to reduce the flow rate cross-section between the first consumer chamber and the outlet chamber (44). A pressure differential, which increases by means of an accumulating load pressure can therefore be partially or wholly compensated, or even overcompensated by the reduction of the flow rate cross-section, thus limiting the lowering speed.
Inventors:
BUETTNER PETER (DE)
MIIKKULAINEN TATU (FI)
MIIKKULAINEN TATU (FI)
Application Number:
PCT/EP2002/004022
Publication Date:
February 20, 2003
Filing Date:
April 11, 2002
Export Citation:
Assignee:
BOSCH REXROTH AG (DE)
BUETTNER PETER (DE)
MIIKKULAINEN TATU (FI)
BUETTNER PETER (DE)
MIIKKULAINEN TATU (FI)
International Classes:
F15B13/04; F15B13/00; (IPC1-7): F15B13/04
Foreign References:
| DE19631803A1 | 1998-02-12 |
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