Hydraulic control device for a mobile machine, especially for a wheel loader
First Claim
1. 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).
1 Assignment
0 Petitions
Accused Products
Abstract
A hydraulic control arrangement for a mobile working machine has at least one hydraulic cylinder with the aid of which a working tool is moved, a directional control valve for controlling pressure-fluid channels between chambers of the hydraulic cylinder, a pressure-fluid source and a tank, a hydraulic accumulator connected to the pressure-fluid source via a filling line, and a control valve to open and to close a connection between the hydraulic accumulator and a pressure chamber of the hydraulic cylinder. To achieve a damping of pitching movement of the machine, a pilot-operated shutoff valve is connected upstream of the pressure chamber of the hydraulic cylinder, and opens when the directional control valve is actuated to allow pressure fluid to flow off from the pressure chamber to the tank.
23 Citations
11 Claims
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1. 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), and
a 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).
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2. A hydraulic control arrangement for a mobile working machine, comprising at least one hydraulic cylinder (12) with aid of which a working tool is movable, 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), and
a control valve (42) with aid of which a connection between the hydraulic accumulator (21) and the pressure chamber (15) of the hydraulic cylinder (12) is controlable to open and close, a pilot-operated shutoff valve (50) which is connected upstream of the pressure chamber (15) and opens toward it 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), wherein, when the directional control valve (11) is actuated, the shutoff valve (50) is supplyable with a control signal via a first control line (54) and, when the control valve (42) is actuated, is supplyable with a control signal via a second control line (55), and wherein there are switch-over means (53, 75) which, as a function of the actuation of the control valve (42), connect a third control line (52) running therebetween and the release means (51) of the shutoff valve (50) of the first control line (54) or the second control line (55).
Specification