Abstract: A hydraulic valve control unit is for an open center hydraulic system including a pump, a shunt valve and one or more actuator valves coupled to the shunt valve. Each actuator valve controls a corresponding actuator's position. The hydraulic valve control unit has a processor and a memory, containing instructions executable by the processor, and is configured to obtain user input data indicative of a desired actuator's position, determining opening area values of the one or more actuator valves using a predetermined relation dependent on the user input data, determining an opening area value of the shunt valve using the predetermined relation dependent on the user input data, controlling the shunt valve based on the opening area value of the shunt valve, and controlling the one or more actuator valves based on the opening area values of the one or more actuator valves.

Abstract: An open center hydraulic system (100) includes a tank configured to hold hydraulic fluid, a pump configured to provide pressurized hydraulic fluid from the tank, and a shunt valve configured to adapt a first opening area between a first input port and a first output port of the shunt valve dependent on a first control signal. The first input port is coupled to the pump, and the first output port is coupled to the tank. A first actuator valve is coupled to the first input port and configured to adapt a second opening area of the first actuator valve dependent on a second control signal. A hydraulic valve control unit is configured to determine a first opening area value and a second opening area value based on user input data and a predetermined relation dependent on the user input data, sending the first control signal, indicative of the first opening area value and sending the second control signal indicative of the second opening area value.

Abstract: The invention relates to a hydraulic valve device (1) including a high pressure connection (P?) and a low pressure connection (T?); at least one motor port connection (A?) that is connectable to a motor port (A) on a hydraulic motor (M), preferably a hydraulic cylinder; a flow control valve (F), which is arranged between the high pressure connection (P?) and the motor port connection (A?) and which includes a flow opening (18) that is adjustable between a fully closed position and a fully open position; and a pressure regulator (R) that is arranged between the high pressure connection (P?) and the flow regulating valve (F), wherein a regulator pressure (PR) that acts at a first connection point (3) between the pressure regulator (R) and the flow regulating valve (F) acts on the pressure regulator (R) via a first control conduit (4) to close the same.

Abstract: A hydraulic valve device includes a first and a second engine port to a double acting hydraulic motor, a pump, a hand valve which has two open positions, wherein in the first open position the pump is fluidly connected to the first engine port and the tank is fluidly connected to the second engine port; and wherein in the second open position the pump is fluidly connected to the second engine port and the tank is fluidly connected to the first engine port, with a first nonreturn valve, arranged between the pump and second engine port. A piston which by way of the load pressure in the first engine port via a line governs the first nonreturn valve, and a second nonreturn valve arranged, as long as the hand valve is in its first open position, to connect the first engine port to the second engine port.

Abstract: A method and a device for controlling a load sensing hydraulic system, having a bypass valve (F), which is controlled by a pump pressure (P) and which when the hydraulic system is in operation diverts a pump flow of hydraulic fluid to a tank (E). The bypass valve (F) is pre-stressed towards a closed position and is put on load by the pump pressure (P) towards an open position against the action of the pre-stress. When the hydraulic system operates in a idling operation a first pre-stress element (I) limits the pre-stress to a first pressure and upon activation of the hydraulic system, a pressure regulator (10) increases the pre-stress to a second, substantially higher pressure by applying a hydraulic, constant second pre-stress force, that is added to the first pre-stress force and is substantially greater than this.

Abstract: A hydraulic load control valve (10) accommodated between a hand valve (H) and a hydraulic engine (D) has got at least one proportional load control valve (E), controlled by the pump pressure independent of the flow of hydraulic fluid to the engine. The flow to the engine (D) flows via a non-return valve (12), that is prestressed to open at a pump pressure above the upper limit before a given pressure interval, within which the load control valve (E) is adjusted between completely closed and completely open position of the pump pressure.

Abstract: A valve fastening element (1) for attaching a hydraulic valve (2) to a tractor (13). The valve fastening element (1) includes a tractor part (1a) adapted to be attached on the tractor and a valve part (1b adapted for direct assembly of the valve (2), wherein the valve (2) includes at least two screw holes (10,11,12), each adapted to receive a screw (3,4,5). The valve part (1b) of the valve fastening element (1) includes at least two slits (6,7,8), of which at least a first slit (6,8) includes an opening (6a,8a) adapted to let the head of the screw pass, and all slits include a groove (6b,7,8b,8c) that is sufficiently narrow to prevent the head of the screw (3,4,5) from passing but sufficiently wide to allow the thread of the screw (3,4,5) to pass.

Abstract: A Hydraulic valve device includes a first engine port and a second engine port to a double acting hydraulic motor, and a pump, a hand valve, which is arranged such that it connects the engine ports to the tank and the pump, and which hand valve has two open positions, wherein the pump in the first open position via a line is connected to the first engine port and the tank via a line is connected to the second engine port, and wherein the pump in the second open position via the line is connected to the second engine port and the tank via the line is connected to the first engine port, and a first nonreturn valve, arranged between the pump and the second engine port and opens towards the second engine port.

Abstract: A hydraulic valve device includes a first and a second engine port to a double acting hydraulic motor, a pump, a hand valve which has two open positions, wherein in the first open position the pump is fluidly connected to the first engine port and the tank is fluidly connected to the second engine port; and wherein in the second open position the pump is fluidly connected to the second engine port and the tank is fluidly connected to the first engine port, with a first nonreturn valve, arranged between the pump and second engine port. A piston which by way of the load pressure in the first engine port via a line governs the first nonreturn valve, and a second nonreturn valve arranged, as long as the hand valve is in its first open position, to connect the first engine port to the second engine port.

Abstract: For a hydraulic system of a work vehicle, a fixed connector part fixedly arranged thereon. A fixed connector part has a plurality of hydraulic couplings. A hydraulic work system of a work equipment has hydraulic couplings which are either a movable part having a plurality of hydraulic couplings or a plurality of individual hydraulic connections, each having a hydraulic coupling. The movable connector part is connectable to the fixed connector part by a locking device. The hydraulic couplings of the fixed connector part are constructed to be hydraulically coupled to the hydraulic couplings of the movable connector part and alternatively to the hydraulic couplings of the plurality of individual hydraulic couplings.

Abstract: A holding device to protect a movable connector part of a hydraulic system on work equipment, which mates with a fixed connector part of a hydraulic system on a work vehicle. The holding device is fixedly mounted on the work equipment and has recesses which receive and protect the hydraulic connections of the movable connector part when they are not engaged with the fixed connector part. The holding device may have a contact surface which mates with the hydraulic connectors of the movable part. The recess or recesses can receive a multipart hydraulic connector or a plurality of individual connectors. The holding device may include an electrical connector dummy for attachment to an electrical connector on the work equipment. A cover fits over the holding device when it is not engaged by a movable connector part; and it also mates with the fixed connector part when it is not engaged by the movable connector part.

Abstract: Wire attachment and attachment method for a sheathed wire including a wire and a sheath coaxially surrounding the wire, the wire attachment including: a housing; an axial bore inside the housing including an opening adapted to receive the sheathed wire; a spool slidably arranged inside the bore, the spool receiving the wire and including an engagement member for fixedly engaging the wire, such that any longitudinal movement of the wire will be transmitted to the spool; a sheath attachment member for fixing the sheath to the wire attachment inside the axial bore at a distance from the receiving bore, such that the spool and the wire are free to move axially with respect to the sheath. The sheath attachment member is arranged to exert a substantially radial pressure onto the surface of the sheath, such that it may be attached essentially without disturbing the axial position of the sheath.

Abstract: A valve fastening element (1) for attaching a hydraulic valve (2) to a tractor (13). The valve fastening element (1) includes a tractor part (1a) adapted to be attached on the tractor and a valve part (1b adapted for direct assembly of the valve (2), wherein the valve (2) includes at least two screw holes (10,11,12), each adapted to receive a screw (3,4,5). The valve part (1b) of the valve fastening element (1) includes at least two slits (6,7,8), of which at least a first slit (6,8) includes an opening (6a,8a) adapted to let the head of the screw pass, and all slits include a groove (6b,7,8b,8c) that is sufficiently narrow to prevent the head of the screw (3,4,5) from passing but sufficiently wide to allow the thread of the screw (3,4,5) to pass.

Abstract: A hydraulic load control valve (10) accommodated between a hand valve (H) and a hydraulic engine (D) has got at least one proportional load control valve (E), controlled by the pump pressure independent of the flow of hydraulic fluid to the engine. The flow to the engine (D) flows via a non-return valve (12), that is prestressed to open at a pump pressure above the upper limit before a given pressure interval, within which the load control valve (E) is adjusted between completely closed and completely open position of the pump pressure.

Abstract: A Hydraulic valve device includes a first engine port and a second engine port to a double acting hydraulic motor, and a pump, a hand valve, which is arranged such that it connects the engine ports to the tank and the pump, and which hand valve has two open positions, wherein the pump in the first open position via a line is connected to the first engine port and the tank via a line is connected to the second engine port, and wherein the pump in the second open position via the line is connected to the second engine port and the tank via the line is connected to the first engine port, and a first nonreturn valve, arranged between the pump and the second engine port and opens towards the second engine port.