Provided is a work machine with which responsiveness of a hydraulic actuator can be improved when driving the hydraulic actuator through an electric lever-type operation device. A controller 100 further includes: an operation direction determining section 116 configured to determine operation directions of operation devices 2a and 2b; and a standby pressure switching command section 117 configured to output a standby pressure switching command to a first target pilot pressure correction section 112 or a second target pilot pressure correction section 113 which corresponds to a solenoid proportional valve that does not correspond to the operation direction from among first solenoid proportional valves 41a, 42a, 42b, 43a, 43b, and 44a and second solenoid proportional valves 41b, 42c, 42d, 43c, 43d, and 44b. The first target pilot pressure correction section and the second target pilot pressure correction section are configured to switch a first standby pressure α to a second standby pressure β set lower than the first standby pressure in a case in which the standby pressure switching command has been inputted.

A work vehicle includes a lifting mechanism to control at least one of a height and a posture of a work machine connected to the work vehicle. The lifting mechanism is able to control at least one of the height and the posture by using a hydraulic drive. The work vehicle includes an oil-temperature acquirer to acquire an oil temperature to be used for the hydraulic drive, a maximum oil amount setter to set a maximum oil amount according to the oil temperature acquired by the oil-temperature acquirer, the maximum oil amount being a maximum value of a supply amount of oil used to drive the hydraulic drive, and a hydraulic drive controller to control the hydraulic drive below the maximum oil amount set by the maximum oil amount setter.

A hydraulic arrangement includes a working pump for conveying a hydraulic medium in a direction of a hydraulic working load, a hydraulic tank comprising a tank outlet hydraulically connected to an inlet side of the working pump, and an auxiliary pump mounted in the hydraulic tank. A hydraulic flow of the hydraulic medium flows in the direction of the tank outlet in dependence on a control system.

An exemplary method generally includes charging hydraulic fluid into or out of a cavity of an accumulator at a controlled flowrate, detecting movement of a machine component from a first position toward a second position, determining an idle time spanning from a start of the charging to detection of the movement of the machine component, and determining a pre-charge of the accumulator based upon the idle time and a flowrate value of the controlled flowrate.

A flow rate control valve includes a first flow line to connect to a first fluid line connected to a hydraulic actuator, a second flow line to connect to a second fluid line connected to the hydraulic actuator, a third flow line to connect to a third fluid line connected to a hydraulic pump, a fourth flow line to connect to an operation fluid tank or a fourth fluid line connected to a suction portion of the hydraulic pump, a fifth flow line to connect a first control valve and a second control valve, and a spool including a first connecting portion being configured to connect the first flow line and the third flow line at a first position and to connect the first flow line and the fifth flow line at a second position.

A hydraulic system for an electric working vehicle or hybrid working vehicle of the kind having an electric source of power and an alternative source of power, the hydraulic system comprising: one or more hydraulically actuated devices; and a hydraulic pump configured to supply hydraulic fluid to the one or more hydraulically actuated devices; wherein the hydraulic pump is configured to operate in a low output state when a flow of hydraulic fluid is not required by the one or more hydraulically actuated devices; and wherein the hydraulic system is configured to use hydraulic fluid supplied by the hydraulic pump in the low output state for one or more auxiliary functions of the hydraulic system.

A control device of a loading machine includes an adjustment determination unit and an operation signal output unit. The loading machine includes a swing motor and a swing body. The adjustment determination unit determines whether or not an angle formed by an azimuth direction of a swing body when the swing body stops and a target stop azimuth direction is less than an allowable angle based on an azimuth direction, a swing speed, and the target stop azimuth direction of the swing body during braking of the swing motor. The operation signal output unit outputs a swing control signal for driving the swing motor in a case in which it is determined that the angle formed by the azimuth direction of the swing body when the swing body stops and the target stop azimuth direction is equal to or greater than the allowable angle.

A work machine includes an operation intention determining section that determines whether or not an operator has an intention of operating an operation member based on a state change of the operation member, a current supply section that supplies a current to a solenoid valve device based on an operation of the operation member, and a current control section that permits supply of a standby current from the current supply section to the solenoid valve device when it has been determined by an operation position determining section that the operation member is disposed within a preset neutral range and it has been determined by the operation intention determining section that there is an intention of operating the operation member, the standby current being lower than a current of the time when a hydraulic actuator starts driving.

A hydraulic system of construction machinery includes: a boom cylinder divided; a first boom hydraulic line serving to supply a hydraulic oil to the boom cylinder during an ascending operation of a boom; a second boom hydraulic line serving to supply the hydraulic oil to the boom cylinder during a descending operation of the boom; a regeneration line serving so that the hydraulic oil discharged from the head side of the boom cylinder flows during the descending operation of the boom; a circulation line connected to the second boom hydraulic line; an accumulator connected to the regeneration line and serving to accumulate the hydraulic oil discharged from the boom cylinder; a boom regeneration valve including a first regeneration spool and a second regeneration spool; and a control unit serving to adjust opening areas of the first regeneration spool and the second regeneration spool during the descending operation of the boom.

In a vibration suppression control OFF state, a signal pressure supply control valve stops supplying a first signal pressure, a pressure-regulating valve is in first position where a supply/discharge port connects to a pump port, and an open/close signal pressure is not supplied to an open/close control valve, so an open/close valve is closed. When the OFF state switches to ON state, the signal pressure supply control valve allows supplying the first signal pressure, and the pressure-regulating valve is in second position where the supply/discharge port connects to a tank port, so the pressure of a pressure accumulator decreases. In the ON state, when the pressure of the pressure accumulator is equal to pressure of a pressure chamber, the pressure-regulating valve is in third position where the supply/discharge port is blocked, and the open/close signal pressure is supplied to the open/close control valve, so the open/close valve is opened.