A hydraulic system for a working machine includes a first electric machine connected to a first hydraulic machine; a second electric machine connected to a second hydraulic machine, an output side of the second hydraulic machine being connected to an input side of the first hydraulic machine; at least one hydraulic consumer hydraulically coupled to an output side of the first hydraulic machine via a supply line and configured to be powered by the first hydraulic machine; and a valve arrangement arranged between the hydraulic consumer and the first and second hydraulic machines, wherein the valve arrangement is configured to control a return flow of hydraulic fluid from the hydraulic consumer to either the input side of the first hydraulic machine or an input side of the second hydraulic machine based on a requested output pressure from the first hydraulic machine.

A throttle check valve includes: a poppet valve body that has an orifice formed at one end and has a hole portion formed at a side portion; a plug that has a tubular shape to surround the poppet valve body, and functions as a valve seat to come into contact with the poppet valve body; and a spring that biases the poppet valve body and the plug functioning as the valve seat in directions to come into contact with each other. When the spool is at the second position, the plug forming the distal end portion of the spool and the plug arranged in the housing come into contact with each other. The plug is provided with a protruding portion that comes into contact with the poppet valve body.

A throttle check valve includes: a poppet valve body that has an orifice formed at one end and has a hole portion formed at a side portion; a plug that has a tubular shape to surround the poppet valve body, and functions as a valve seat to come into contact with the poppet valve body; and a spring that biases the poppet valve body and the plug functioning as the valve seat in directions to come into contact with each other. When the spool is at the second position, the plug forming the distal end portion of the spool and the plug arranged in the housing come into contact with each other. The plug is provided with a protruding portion that comes into contact with the poppet valve body.

The present application provides a full hydraulic synchronous steering system for a low-speed heavy-load vehicle, where the system includes: a steering control mechanism and a steering actuator; by determining a desired steering curve between a steering wheel angle and a rear wheel angle, when a steering error exceeds an allowable error, a controller controls the opening and closing of an oil replenishment solenoid valve (5) and an oil discharge solenoid valve (4) to adjust a flow rate of the oil flowing into a steering cylinder (7), so as to ensure that the steering error is within an allowable error range, thereby implementing synchronous steering. A method for manipulating the full hydraulic synchronous steering system is further provided. The full hydraulic synchronous steering system and the method can improve synchronous steering capability of the low-speed heavy-load vehicle and change a steering ratio, thereby improving safety and direction feeling of a driver.

The present application provides a full hydraulic synchronous steering system for a low-speed heavy-load vehicle, where the system includes: a steering control mechanism and a steering actuator; by determining a desired steering curve between a steering wheel angle and a rear wheel angle, when a steering error exceeds an allowable error, a controller controls the opening and closing of an oil replenishment solenoid valve (5) and an oil discharge solenoid valve (4) to adjust a flow rate of the oil flowing into a steering cylinder (7), so as to ensure that the steering error is within an allowable error range, thereby implementing synchronous steering. A method for manipulating the full hydraulic synchronous steering system is further provided. The full hydraulic synchronous steering system and the method can improve synchronous steering capability of the low-speed heavy-load vehicle and change a steering ratio, thereby improving safety and direction feeling of a driver.

The present disclosure relates to a hydraulic steering device of an agricultural work vehicle comprising a steering pump for supplying a working fluid; an automatic steering unit which uses the working fluid to change the traveling direction of the agricultural work vehicle when automatic steering is performed by a control unit; a manual steering unit which uses the working fluid to change the traveling direction of the agricultural work vehicle when manual steering is performed by operating a steering handle; and an automatic cut-off unit which is for selectively cutting off the supply of the working fluid for the automatic steering to a steering cylinder of the agricultural work vehicle according to whether the manual steering is performed.

The present disclosure relates to a hydraulic steering device of an agricultural work vehicle comprising a steering pump for supplying a working fluid; an automatic steering unit which uses the working fluid to change the traveling direction of the agricultural work vehicle when automatic steering is performed by a control unit; a manual steering unit which uses the working fluid to change the traveling direction of the agricultural work vehicle when manual steering is performed by operating a steering handle; and an automatic cut-off unit which is for selectively cutting off the supply of the working fluid for the automatic steering to a steering cylinder of the agricultural work vehicle according to whether the manual steering is performed.

A work vehicle includes a wheel supporting member 11 that is supported by a vehicle body frame 1 that includes left and right side members 80; left and right steerable wheels that are supported by the wheel supporting member 11 so as to be steerable; and a steering mechanism 25 that includes a power steering unit 24 and steers the left and right steerable wheels. The power steering unit 24 is located near the wheel supporting member 11 such that at least a portion of the power steering unit 24 is located between the left and right side members 80.

A work vehicle includes a wheel supporting member 11 that is supported by a vehicle body frame 1 that includes left and right side members 80; left and right steerable wheels that are supported by the wheel supporting member 11 so as to be steerable; and a steering mechanism 25 that includes a power steering unit 24 and steers the left and right steerable wheels. The power steering unit 24 is located near the wheel supporting member 11 such that at least a portion of the power steering unit 24 is located between the left and right side members 80.

The present invention is to provide a vehicle-mounted apparatus having a biasing structure using a coil spring capable of reducing a lateral force of a coil spring that is applied to a biasing target member. When N1, n1, N0, and n0 represent the number of effective turns when the relief valve spring 37 is set in a valve hole 34 of a spool 29 in a compressed state, a value of an integer of N1, the number of effective turns when a length of the relief valve spring 37 is a natural length, and a value of an integer of N0, respectively, the spring 37 satisfies an equation 1: 0≤N1−n1≤0.25 or an equation 2: 0.75≤N1−n1<1.