Patent ID: 6370874
Filing Date: 2002-04-16
Classification: E02F

Abstract:
A hydraulic control arrangement for a mobile working machine, comprising at least one hydraulic cylinder (12) with aid of which a working tool can be moved, a directional control valve (11) for controlling the pressure-fluid channels between a pressure chamber (15) of the hydraulic cylinder (12), a pressure-fluid source and a tank (27), a hydraulic accumulator (21) which is connectable to the pressure-fluid source via a filling line (20), anda control valve (42) with aid of which a connection between the hydraulic accumulator (21) and the pressure chamber (15) of the hydraulic cylinder (12) can be controlled to open and close, a pilot-operated shutoff valve (50) which is connected upstream of the pressure chamber (15) and opens toward it, wherein the pilot-operated shutoff valve (50) is arranged between the directional control valve (11) and the pressure chamber (15) of the hydraulic cylinder (12) and is controllable to open when the directional control valve (11) is actuated to allow pressure fluid to flow off from the pressure chamber (15) to the tank (27) and when the control valve (42) is actuated to establish a fluid connection between the pressure chamber (15) and the hydraulic accumulator (21).