An articulated work vehicle includes a hydraulic actuator, a control valve, a joystick lever, and a first link mechanism. A front frame is linked to a rear frame. The hydraulic actuator is configured to be driven by hydraulic pressure and configured to change a steering angle of the front frame with respect to the rear frame. The control valve is configured to control flow of fluid supplied to the hydraulic actuator. The joystick lever is disposed in a cab provided on the rear frame. The joystick lever is configured to be operated by an operator. The first link mechanism is disposed below the cab. The first link mechanism is configured to transmit an operation of the joystick lever to the control valve.

An articulated work vehicle includes a hydraulic actuator, a control valve, a joystick lever, and a first link mechanism. A front frame is linked to a rear frame. The hydraulic actuator is configured to be driven by hydraulic pressure and configured to change a steering angle of the front frame with respect to the rear frame. The control valve is configured to control flow of fluid supplied to the hydraulic actuator. The joystick lever is disposed in a cab provided on the rear frame. The joystick lever is configured to be operated by an operator. The first link mechanism is disposed below the cab. The first link mechanism is configured to transmit an operation of the joystick lever to the control valve.

A work vehicle includes a hydraulic actuator, a hydraulic pump, an operation member, a control valve, an angular velocity corresponding value sensing unit, a notification component, and a controller. The actuator changes a steering angle based on a supplied fluid. The pump supplies fluid to the actuator. The operation member is operated by an operator when the steering angle is changed. The valve controls flow of fluid supplied from the pump to the actuator based on an amount the operation member is operated. The sensing unit senses a corresponding value corresponding to a steering angular velocity changed based on the flow of fluid. The notification component notifies that the corresponding value has reached a threshold value preset based on an upper limit of the steering angular velocity. The controller causes the notification component to perform a notification when it is detected that the corresponding value has reached the threshold value.

A work vehicle includes a hydraulic actuator, a hydraulic pump, an operation member, a control valve, an angular velocity corresponding value sensing unit, a notification component, and a controller. The actuator changes a steering angle based on a supplied fluid. The pump supplies fluid to the actuator. The operation member is operated by an operator when the steering angle is changed. The valve controls flow of fluid supplied from the pump to the actuator based on an amount the operation member is operated. The sensing unit senses a corresponding value corresponding to a steering angular velocity changed based on the flow of fluid. The notification component notifies that the corresponding value has reached a threshold value preset based on an upper limit of the steering angular velocity. The controller causes the notification component to perform a notification when it is detected that the corresponding value has reached the threshold value.

A hydraulic driving device of an industrial vehicle includes: a tank which stores hydraulic oil; a hydraulic pump which includes a suction port sucking the hydraulic oil and a discharge port discharging the hydraulic oil; a hydraulic cylinder which is driven by the hydraulic oil discharged from the discharge port of the hydraulic pump; a direction switching valve which is disposed among the hydraulic pump, the tank, and the hydraulic cylinder and switches a hydraulic oil flow direction in response to an operation state of operation means for driving the hydraulic cylinder; in which the direction switching valve includes a main spool which moves in response to the operation state of the operation means and a flow regulator which is disposed inside the main spool to control a flow rate of the hydraulic oil flowing from the hydraulic cylinder to the tank.

A hydraulic driving device of an industrial vehicle includes: a tank which stores hydraulic oil; a hydraulic pump which includes a suction port sucking the hydraulic oil and a discharge port discharging the hydraulic oil; a hydraulic cylinder which is driven by the hydraulic oil discharged from the discharge port of the hydraulic pump; a direction switching valve which is disposed among the hydraulic pump, the tank, and the hydraulic cylinder and switches a hydraulic oil flow direction in response to an operation state of operation means for driving the hydraulic cylinder; in which the direction switching valve includes a main spool which moves in response to the operation state of the operation means and a flow regulator which is disposed inside the main spool to control a flow rate of the hydraulic oil flowing from the hydraulic cylinder to the tank.

An autonomous steering control unit for a hydraulic steering control system has a pilot selector valve, primary and secondary electro-hydraulic (EH) steering valves, and an output selector valve. In a primary autonomous steering mode, the primary EH steering valve operates to output pilot fluid from the pilot selector valve through the output selector valve to the steering control system to control steering of a work machine while the pilot selector valve and the output selector valve isolate the secondary EH steering valve from the steering control system. In a secondary autonomous steering mode, the secondary EH steering valve operates to output pilot fluid through the output selector valve to the steering control system while the primary EH steering valve is isolated from the steering control system. In alternative embodiments, a load sense selector valve alternately connects an dynamic load sense line to the operative steering valve.

An autonomous steering control unit for a hydraulic steering control system has a pilot selector valve, primary and secondary electro-hydraulic (EH) steering valves, and an output selector valve. In a primary autonomous steering mode, the primary EH steering valve operates to output pilot fluid from the pilot selector valve through the output selector valve to the steering control system to control steering of a work machine while the pilot selector valve and the output selector valve isolate the secondary EH steering valve from the steering control system. In a secondary autonomous steering mode, the secondary EH steering valve operates to output pilot fluid through the output selector valve to the steering control system while the primary EH steering valve is isolated from the steering control system. In alternative embodiments, a load sense selector valve alternately connects an dynamic load sense line to the operative steering valve.

A fluid controller (1), in particular as part of a hydraulic steering unit, is described said controller (1) comprising a housing (2) having a supply port arrangement, a sleeve (4) arranged rotatably in a bore of the housing (2), a spool (3) arranged rotatably in the sleeve (4), and a measuring motor, wherein the measuring motor comprises a plurality of working chambers, each working chamber being connected to the bore, wherein the sleeve (4) comprises a commutation geometry (7) having a first partition and controlling together with a housing geometry (5) of the housing (2) a flow of hydraulic fluid into and out of the working chambers and the spool (3) comprises a spool geometry (14) controlling together with a valve geometry (10, 11) of the sleeve (4) a flow of hydraulic fluid between the supply port arrangement and the commutation geometry. Such a fluid controller should have a stable control behavior. To this end the valve geometry (10,11) comprises a second partition different from the first partition.

A fluid controller (1), in particular as part of a hydraulic steering unit, is described said controller (1) comprising a housing (2) having a supply port arrangement, a sleeve (4) arranged rotatably in a bore of the housing (2), a spool (3) arranged rotatably in the sleeve (4), and a measuring motor, wherein the measuring motor comprises a plurality of working chambers, each working chamber being connected to the bore, wherein the sleeve (4) comprises a commutation geometry (7) having a first partition and controlling together with a housing geometry (5) of the housing (2) a flow of hydraulic fluid into and out of the working chambers and the spool (3) comprises a spool geometry (14) controlling together with a valve geometry (10, 11) of the sleeve (4) a flow of hydraulic fluid between the supply port arrangement and the commutation geometry. Such a fluid controller should have a stable control behavior. To this end the valve geometry (10,11) comprises a second partition different from the first partition.