Hydraulic control arrangement
What is disclosed is a hydraulic control arrangement for controlling a hydraulic consumer, comprising an adjustable supply measuring orifice and an adjustable drain measuring orifice as well as a pressure compensator arranged in a pressure medium delivery. The control arrangement moreover comprises a releasable cut-off block that acts as a check valve in the direction of supply and may be released in the direction of drain by means of a control pressure. In accordance with the invention, the pressure compensator is subjected to a constant force in the opening direction and to the lower one of the pressures downstream from the supply measuring orifice and upstream from the drain measuring orifice in the closing direction.
1. A hydraulic control arrangement for controlling a hydraulic consumer, comprising an adjustable supply measuring orifice and an adjustable drain measuring orifice, a pressure compensator arranged in a pressure medium delivery for controlling the pressure medium volume flow across the supply measuring orifice and comprising at least one releasable cut-off block that acts as a check valve in direction of supply and is releasable by means of a control pressure (p x ) in the direction of drain, characterized in that the pressure compensator is subjected to a constant force (p x ) in the opening direction and to the lower one of the pressures downstream from the supply measuring orifice and upstream from the drain measuring orifice.
2. The control arrangement in accordance with claim 1 , wherein a flow rate of a pump is adjustable in dependence on the higher one of the two pressures.
3. The control arrangement in accordance with claim 1 , wherein the drain measuring orifice and supply measuring orifice are formed by a continuously adjustable directional control valve.
4. The control arrangement in accordance with claim 3 , wherein the supply cross-section controlled open by a supply control edge is larger than the drain cross-section controlled open by a drain control edge.
5. The control arrangement in accordance with claim 1 , wherein the constant force is applied by a control pressure (p x ) acting on a control surface of the pressure compensator and/or by a spring.
6. The control arrangement in accordance with claim 5 , first alternative, wherein the constant pressure (p x ) may be varied or reduced to Zero.
7. The control arrangement in accordance with claim 1 , wherein in the supply and in the drain a respective releasable cut-off block is arranged which includes a topping piston adapted to be actuated by a control pressure.
8. The control arrangement in accordance with claim 7 , wherein the topping piston is subjected to the pressure in the drain in the direction opposite to the control pressure.
9. The control arrangement in accordance with claim 7 , wherein the control pressure corresponds to the constant control pressure (p x ).
10. The control arrangement in accordance with claim 1 , wherein the lower pressure is tapped via an inverse shuttle valve.