1. Control Device

2. A control device for controlling a hydraulic consumer (2), such as a working cylinder, consisting of at least one control valve (18) having a control spool (20), which is guided in a valve housing (22) in a longitudinally movable manner and which can be actuated by means of an electric motor (24) and which can be controlled by means of control electronics (MC), which receive input signals from a sensor device (58, 60, 62), which detects at least one operating state of the consumer (2).

A servo valve has a movable element disposed inside a body, and a drive unit to slide the movable element in the axial direction. A first elastic portion on one end portion side of the body has a first elastic force to press the movable element toward the drive unit connected to another end portion of the body; a second elastic portion on another end portion side of the body has a second elastic force to press the movable element toward the one end portion side of the body. A connecting portion is connected to the second elastic portion, wherein at a neutral position of the movable element, the connecting portion abuts against an inner peripheral surface of the body and against the movable element. An end of one of the first and second elastic portions is fixed directly to the movable element, and an end of the other of the first and second elastic portions is connected to the connecting portion.

A servo valve has a movable element disposed inside a body, and a drive unit to slide the movable element in the axial direction. A first elastic portion on one end portion side of the body has a first elastic force to press the movable element toward the drive unit connected to another end portion of the body; a second elastic portion on another end portion side of the body has a second elastic force to press the movable element toward the one end portion side of the body. A connecting portion is connected to the second elastic portion, wherein at a neutral position of the movable element, the connecting portion abuts against an inner peripheral surface of the body and against the movable element. An end of one of the first and second elastic portions is fixed directly to the movable element, and an end of the other of the first and second elastic portions is connected to the connecting portion.

Embodiments of the disclosure include a redundant control system for a vehicle. The redundant control system includes first and second actuator pistons mechanically coupled to one another and disposed in respective first and second fluid chambers. The first and second actuator pistons are movable by first and second primary stages. One of the primary stages includes a bypass valve with a pilot valve actuatable in response to movement of the first actuator piston.

A ram air turbine (RAT) restow system includes an actuator assembly with a piston interposed between an upper fluid compartment and a lower fluid compartment. The actuator assembly is configured to selectively move the piston between a deployed position and a stowed position. A hydraulic restow circuit is interposed between the actuator assembly and a hydraulic fluid system that is configured to output fluid. The hydraulic restow circuit includes a restow valve configured to operate in a first position that establishes a first fluid path to deliver the fluid to the upper fluid compartment and a second position that establishes a second fluid path to deliver the fluid to the lower fluid compartment.

The invention relates to a valve, which is characterized in that between a neutral position (38) of a control spool (STS) and one of its end positions (34, 42) a regeneration position (36) is provided, in which two utility ports (A, B) are interconnected in a fluid-conveying manner, or a floating position (40) is provided, in which these utility ports (A, B) are interconnected in a fluid-conveying manner. The invention relates to a further valve, which is characterized in that by a further motion of the control spool (STS) in the same direction, as that, in which a fluid connection is established between the utility ports (A, B) starting from the neutral position (38), this fluid connection is interrupted.

A work vehicle provided with a loading hydraulic circuit (A), including at least a main hydraulic pump (31), a lift aim cylinder (8) and a control valve (32), an auxiliary hydraulic pump (31), a negative parking brake device (PB), and a parking brake releasing hydraulic circuit (B2), in which the vehicle includes: a loading operation hydraulic circuit (B1) located upstream of the parking brake releasing hydraulic circuit; an emergency flow path (80) for supplying the pressure oil discharged from the auxiliary hydraulic pump to the parking brake device through the loading operation hydraulic circuit in an emergency; and a valve unit (81) located in the emergency flow path. If the pressure of the parking brake releasing hydraulic circuit is lower than the brake release pressure to release the braking state of the parking brake device, the valve unit is switched to the communicating position.

This hydraulic system is provided with: a hydraulic pump; a pilot-type control valve; an electromagnetic proportional valve; a controller; and a pilot pressure switching unit which is capable of switching the electromagnetic proportional valve supply pressure to a first pressure during a normal operation, or to a second pressure lower than the first pressure. The control valve is provided with a bleed-off passage, and is capable of controlling the operating oil pressure supplied to the actuator, according to the opening area thereof. During an emergency operation, the electromagnetic proportional valve supply pressure is switched from the first pressure to the second pressure, the electromagnetic proportional valve is brought into a fully opened state, and the operating oil discharge amount from the hydraulic pump increases and decreases, and the operating oil pressure increases and decreases, and thus the operating speed of the actuator is controlled.

Embodiments of the disclosure include a redundant control system for a vehicle. The redundant control system includes first and second actuator pistons mechanically coupled to one another and disposed in respective first and second fluid chambers. The first and second actuator pistons are movable by first and second primary stages. One of the primary stages includes a bypass valve with a pilot valve actuatable in response to movement of the first actuator piston.

The invention relates to a control device for a hydraulic consumer (22), susceptible to vibrations, comprising a valve (24) having a control spool (40), which can be controlled by means of an actuating device (46), wherein the valve (24) has a pressure supply port (P), to which a pressure compensator valve can be connected, which can be supplied with pressure fluid from a pressure supply device, wherein the actuating device (46) has a motor (74) and wherein a load-pressure-dependent force on the control spool (40) can be generated by means of a control device (66). In accordance with the invention, this force at the control spool (40) acts on an electronic motor controller (208) of the DC motor (74), which detects a change of the force and acts as a damping of the vibrations of the consumer (22) against this change of force.