A steering system for an agricultural vehicle that includes a steering wheel, a steering wheel sensor operably connected to the steering wheel, a drive selector having a forward position, a neutral position, and a reverse position, an actuating device configured for being operably connected to the steerable wheels of the agricultural vehicle, and an electronic control unit operably connected to the steering wheel sensor, the drive selector, and the actuating device. The electronic control unit is configured for selectively preventing a rotation of the steering wheel from steering the steerable wheels in the neutral position of the drive selector.

Provided is a working vehicle capable of increasing lifting operation speed of a working device without increasing cost, even when provided with a circuit configuration that prioritizes a steering operation over a working device operation.

A wheel loader 1 comprises a priority valve 451 configured to allow hydraulic oil discharged from a hydraulic pump 41 to flow into a steering drive circuit 43 preferentially over a working device drive circuit 44, and further comprises: an electric steering lever 30; a pair of solenoid control valves 34A, 34B configured to control a steering directional control valve 33; and a controller 5. The controller 5 is configured to control the pair of solenoid control valves 34A, 34B so as to limit operation speed of a steering 3 when determining that an engine 40 is in a low idle state and a lift arm 21 is performing a lifting operation.

The invention relates to a hydraulic steering device that hydraulically connects a steering cylinder to a supply system, whereby the supply system is hydraulically operatively connectable to the steering cylinder via a steering valve to form a main flow connection and the supply system is hydraulically operatively connectable to the steering cylinder via a flow regulation valve arrangement to form a branch flow connection that circumvents the main flow connection, whereby the flow regulation valve arrangement is triggerable by an electric control unit and the flow regulation valve arrangement comprises valve groups that are triggerable individually, which are respectively connected in the forward flow and return flow of the branch flow connection and a release-shutoff valve is assigned to the flow regulation valve arrangement. It is provided that the release-shutoff valve is connected between the flow regulation valve arrangement and the steering cylinder.

A valve for hydraulic parallel work systems is provided. The valve includes a first pair of ports, a second pair of ports, a first connection, and a second connection. The first connection is between the first pair of ports when the valve is in a load reaction-enabling state. The first connection transmits a load reaction from a load at a steering actuator to a steering device of a hydrostatic steering circuit. The second connection is between the second pair of ports when the valve is in an electro-hydraulic steering enabling state. The second connection fluidly connects a fluid source to an electro-hydraulic steering circuit.

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 hydraulic steering device which hydraulically connects a steering cylinder to a supply system. The supply system is hydraulically operatively connectable to the steering cylinder via a steering assembly for the purposes of forming a main flow connection, and the supply system is furthermore hydraulically operatively connectable to the steering cylinder via a flow regulating valve arrangement, such that a secondary flow connection can be formed which bypasses the main flow connection and via which at least one first working chamber and one second working chamber of the steering cylinder can be supplied independently of one another with hydraulic fluid.

A steer by wire steering system includes a steering wheel selectively coupled to a steering shaft, the steering wheel and steering shaft axially movable between a deployed position and a retracted position; an advanced driver assist system configured to steer the steerable wheels of a vehicle that is in communication with the steering wheel and steering shaft, the ADAS configured to selectively control the steering of the steerable wheels in an autonomous driving mode and a manual driving mode; and a steering system controller in communication with the ADAS, the steering system controller programmed to, while the steering wheel is in the retracted position, move the steering wheel to the deployed position and operatively couple the steering wheel to the steering shaft, in response to a vehicle operator request to deactivate a portion of the ADAS and transition from the autonomous driving mode to the manual driving mode.

A work vehicle includes a hydraulic actuator that changes an actual steering angle, an actual steering angle detecting part, an operating unit that performs a steering operation, a position adjusting control part that controls the position adjusting part based on the actual steering angle, and a steering control part that controls the hydraulic actuator. The operating unit includes a support part, a rotating part supported rotatably by the support part, an operating part supported rotatably by the support part or the rotating part, a biasing part that biases the operating part to a predetermined position with respect to the rotating part, a position adjusting part that adjusts a rotation angle of the rotating part with respect to the support part, and a rotation angle detecting part configured to detect the rotation angle of the operating part with respect to the support part or the rotating part.

A steering system and method is described for a vehicle having steerable front and rear wheels, and a steering input device for receiving manual steering input. Front and rear hydraulic steering devices may be coupled, respectively, to the front and rear wheels. Front and rear valve assemblies may be configured, respectively, to steer the front and rear wheels. In a manual steering mode, the front valve assembly may be disabled with respect to the front steering device, and the front hydraulic steering device may steer the front wheels based upon the manual steering input. In a rear steering assist mode, a rear steering command may be determined based upon the manual steering input, and the rear wheels steered based upon the rear steering command. In an automated steering mode, the front and rear wheels may be automatically steered based upon a target path of travel for the vehicle.

An electronic control unit (ECU) may receive, from an autonomous vehicle controller, an instruction to set a hydraulic steering actuator, of a vehicle, to a particular machine steering angle setting. The ECU may provide, to a steering controller torque device, a current to set a steering controller, of the vehicle, to a particular steering controller angle that corresponds to the particular machine steering angle setting. The ECU may provide, to a hydraulic control system, a current to set the hydraulic steering actuator to the particular machine steering angle setting.