A hydraulic steering system, comprising a steering pump and a plurality of digital steering cylinder assemblies Each digital steering cylinder assembly includes a steering cylinder and a digital hydraulic valve configured to selectively communicate a rodless cavity of the steering cylinder with one of the steering pump and a return oil circuit, and communicate a rod cavity of the steering cylinder with the other of the steering pump and the return oil circuit.A controller can be configured to emit a digital pulse signal to a motorand cause the digital hydraulic valve to move towards a first working position or a second working position andA mechanical feedback structure can be configured to be driven by a piston rod of the steering cylinder when the valve core of the digital hydraulic valve moves towards the first working position or the second working position, so as to drive the digital hydraulic valve to return to a neutral position. The system can improve the control precision and the response speed of the steering system.

A hydraulic steering system, comprising a steering pump and a plurality of digital steering cylinder assemblies Each digital steering cylinder assembly includes a steering cylinder and a digital hydraulic valve configured to selectively communicate a rodless cavity of the steering cylinder with one of the steering pump and a return oil circuit, and communicate a rod cavity of the steering cylinder with the other of the steering pump and the return oil circuit.A controller can be configured to emit a digital pulse signal to a motorand cause the digital hydraulic valve to move towards a first working position or a second working position andA mechanical feedback structure can be configured to be driven by a piston rod of the steering cylinder when the valve core of the digital hydraulic valve moves towards the first working position or the second working position, so as to drive the digital hydraulic valve to return to a neutral position. The system can improve the control precision and the response speed of the steering system.

A method of controlling a work vehicle including a steering cylinder operating a steering wheel by hydraulic oil supplied thereto, a steering member receiving an input for operating the steering wheel, and a steering valve unit which is connected to the steering member and supplies the hydraulic oil to the steering cylinder, the method includes: obtaining a speed of the work vehicle and a steering angle of the steering wheel; and decreasing a correction factor for correcting a deviation amount of actual steering angle information of the steering wheel with respect to target information as information on a target steering angle of the steering wheel with respect to an operation amount of the steering member when the speed of the work vehicle increases in a case where the steering angle of the steering wheel obtained based on the steering angle is in a predetermined range from a neutral position.

A method of controlling a work vehicle including a steering cylinder operating a steering wheel by hydraulic oil supplied thereto, a steering member receiving an input for operating the steering wheel, and a steering valve unit which is connected to the steering member and supplies the hydraulic oil to the steering cylinder, the method includes: obtaining a speed of the work vehicle and a steering angle of the steering wheel; and decreasing a correction factor for correcting a deviation amount of actual steering angle information of the steering wheel with respect to target information as information on a target steering angle of the steering wheel with respect to an operation amount of the steering member when the speed of the work vehicle increases in a case where the steering angle of the steering wheel obtained based on the steering angle is in a predetermined range from a neutral position.

The present invention discloses a drive-by-wire electro-hydraulic steering system based on a double-winding motor and a hybrid control method. The steering system includes a steering wheel (1), a steering column assembly, a road sense assembly, an electro-hydraulic power-assisted module, a double-winding motor power-assisted module (28), a steering control unit, an electromagnetic clutch (8), a steering tie rod (17), a steering trapezoid (13) and steering wheels (12). The steering system can be switched among various steering work modes according to work conditions of a vehicle, meets steering requirements under various work conditions, uses a work mode that two sets of windings of the double-winding motor work at the same time, and has a motor winding redundancy function. When one set of windings fails, the other set of windings can drive the motor to provide power-assisted torque.

A steering system for an articulated truck. The articulated truck is formed of a tractor and a trailer and an articulation joint. The steering system includes a hydraulic cylinder, with a cylinder barrel and a piston. The steering system provides for changes in angle between the tractor and the trailer. The hydraulic cylinder includes a snubbing tube projecting into the cylinder barrel. A hydraulic fluid passage opens into the cylinder barrel within the snubbing tube. The snubbing tube includes a main slot and a plurality of channels each extending between an interior and an exterior of the snubbing tube. The plurality of channels have a cross sectional area smaller than a cross sectional area of the main slot. When the articulated truck is steered, the piston moves in the cylinder barrel and the snubbing tube dampens the movement to prevent forces generated by the piston damaging the articulated truck.

A steering system for an articulated truck. The articulated truck is formed of a tractor and a trailer and an articulation joint. The steering system includes a hydraulic cylinder, with a cylinder barrel and a piston. The steering system provides for changes in angle between the tractor and the trailer. The hydraulic cylinder includes a snubbing tube projecting into the cylinder barrel. A hydraulic fluid passage opens into the cylinder barrel within the snubbing tube. The snubbing tube includes a main slot and a plurality of channels each extending between an interior and an exterior of the snubbing tube. The plurality of channels have a cross sectional area smaller than a cross sectional area of the main slot. When the articulated truck is steered, the piston moves in the cylinder barrel and the snubbing tube dampens the movement to prevent forces generated by the piston damaging the articulated truck.

The present invention provides a work machine including a steering device that is very responsive to switching operations. The work machine includes: a proportional solenoid valve for outputting a first pilot pressure oil with a pressure responding to a steering signal; a solenoid valve for outputting a second pilot pressure oil with a predetermined pressure while the steering signal is outputted from the steering device; a switching valve capable of switching to a first state of outputting the first pilot pressure oil to a directional control valve and a second state of outputting the second pilot pressure oil to the directional control valve, while the first pilot pressure oil is outputted from the proportional solenoid valve and the second pilot pressure oil is outputted from the solenoid valve in parallel; and a controller to switch the switching valve from the first state to the second state in a case where a malfunction is detected in a main circuit ranging from the steering device to the directional control valve via the proportional solenoid valve and the switching valve of the first state.

The present invention provides a work machine including a steering device that is very responsive to switching operations. The work machine includes: a proportional solenoid valve for outputting a first pilot pressure oil with a pressure responding to a steering signal; a solenoid valve for outputting a second pilot pressure oil with a predetermined pressure while the steering signal is outputted from the steering device; a switching valve capable of switching to a first state of outputting the first pilot pressure oil to a directional control valve and a second state of outputting the second pilot pressure oil to the directional control valve, while the first pilot pressure oil is outputted from the proportional solenoid valve and the second pilot pressure oil is outputted from the solenoid valve in parallel; and a controller to switch the switching valve from the first state to the second state in a case where a malfunction is detected in a main circuit ranging from the steering device to the directional control valve via the proportional solenoid valve and the switching valve of the first state.

Hydraulic steering (1) is disclosed comprising a high pressure port (P), a low pressure port (T), two working ports (CL, CR), a manual steering section (3), and a steering valve section having a steering valve 5 and a hydraulic driving arrangement (6) adjusting hydraulically a position of said steering valve. A change from automatic steering to manual steering should be reliably ensured when the manual steering section is directly influenced by a driver. To this end, a switching valve (11) is provided, which is actuatable between a first position in which said driving arrangement (6) is supplied with hydraulic fluid under pressure, and a second position in which a supply of hydraulic fluid to said driving arrangement (6) is interrupted, wherein said switching valve (11) is hydraulically actuated into said second position by a pressure generated upon actuating of said manual steering section (3).