A system for controlling a hydraulic component. The system includes a control system configured to carry out a health check routine having steps of (A) fluidly connecting one of the hydraulic supply systems with the component until (i) a predetermined pressure is reached on the hydraulic supply side and/or the hydraulic return side, and/or (ii) a predetermined amount of time has passed; then (B) isolating the pressurised hydraulic fluid within the hydraulic supply side and the hydraulic return side so that hydraulic fluid leaks from the hydraulic supply side to the hydraulic return side via the controlled leakage; (C) monitoring the pressure of hydraulic fluid within the hydraulic supply side (50S) and/or the hydraulic return side over time; and then (D) determining if the pressure of hydraulic fluid within the hydraulic supply side and/or the hydraulic return side follows a predetermined or expected pattern.

A hydraulic system of a working machine includes a hydraulic pump to output a hydraulic fluid, at least one proportional valve to deliver the hydraulic fluid to a supply target, a valve body including the proportional valve, a heat-up fluid passage in the valve body and into which the hydraulic fluid flows, a switching valve switchable between an open position in which the hydraulic fluid passing through the heat-up fluid passage is supplied to a hydraulic device and a closed position in which the hydraulic fluid is not supplied thereto and the hydraulic fluid from the hydraulic device is to be returned, a controller to operate the switching and proportional valves, and a return circuit through which the hydraulic fluid flowing into the heat-up fluid passage is returned as a result of at least one of the switching and proportional valves being operated by the controller.

A work machine control system includes: a pump; a cylinder operating a working equipment element in a movable range based on hydraulic oil supplied from the pump; a first path connected to the pump; a second path branching from the first path; a control valve adjusting the flow rate of the oil supplied to the cylinder via the first path; a bleed valve adjusting the flow rate of the oil discharged to a tank via the second path; a sensor detecting a posture of the element in the range; and a control device outputting a first command for adjusting the flow rate of the oil supplied to the cylinder and a second command for adjusting the flow rate of the oil discharged to the tank when element is determined to be present in an end section of the range based on detection data of the sensor.

A closed-circuit, self-contained hydraulic axis includes an electric motor, a hydraulic cylinder configured to be connected to a load and a main pump driven by the electric motor to pump hydraulic fluid through the circuit. Pressure connections of the pump are connected to the respective chambers of the cylinder such that the cylinder rod is configured to extend and retract depending on a direction of flow of the hydraulic fluid through the main pump. The hydraulic axis includes a main accumulator connected to the pump via first control valve, an energy storage accumulator connected to the pump via a second control valve, and a charge pump. The hydraulic axis is switchable between a first operating mode that is free of energy storage in the energy storage accumulator, and a second operating mode in which energy is stored in the energy storage accumulator.

A method for controlling a control surface multirod actuator arrangement and the arrangement including: a first and a second multirod actuator configured to move or clamp around a first set of piston rods; a third multirod actuator configured to move or clamp around a second set of piston rods; a control unit configured to control motion of the first set of piston rods in a first motion mode and to control motion of the second set of piston rods in a second motion mode. Steps are moving at least one piston rod of first set of piston rods and/or clamping in parked position at least one piston rod of the second set of piston rods.

A hydraulic system includes: a slewing motor; a mechanical brake; and a slewing control valve interposed between a main pump and the slewing motor. A first pilot port of the slewing control valve is connected to a first solenoid proportional valve by a pilot line. A second pilot port of the slewing control valve is connected to a second solenoid proportional valve by a second pilot line. The first solenoid proportional valve and the second solenoid proportional valve are connected to an auxiliary pump by a primary pressure line. A switching valve is interposed between the auxiliary pump and the mechanical brake. The switching valve includes a pilot port that is connected to the first pilot line by a switching pilot line. The valve switches from a closed to an open position when a pilot pressure led to the pilot port becomes higher than or equal to a setting value.

A construction machine that makes it possible for an operator to linearly push a bucket simply by operating an arm in a pushing direction is provided. A controller 50 is configured to, in a case where a straight locus is selected by a bucket locus selecting device 52, calculate a constant flow rate ratio α according to a boom initial angle that is an angle of a boom 2 sensed by a boom angle sensor 33 at a time point when an arm 4 is operated in a pushing direction by an operation device 51, and control the delivery flow rate of a first hydraulic pump 12 such that a hydraulic fluid is discharged from a cap chamber 1a of a boom cylinder 1 at a flow rate Qb obtained by multiplying a flow rate Qa of a flow supplied to a cap chamber 3a of an arm cylinder 3 by the flow rate ratio α while the arm 4 is operated in the pushing direction by the operation device 51 and there is not an instruction for operation of the boom 2.

To be capable of dealing with a machine body lifting operation or a sudden operation, while improving energy efficiency, during a boom-lowering operation, and achieving the reduction of the number of parts, in a construction machine equipped with a boom. It is configured such that a first region Y1 at which a recovery valve passage 16e is opened and a supply valve passage 16f is closed and a second region Y2 at which the recovery valve passage 16e and the supply valve passage 16f are opened, are provided at an operating position of a first boom control valve 16 during the boom lowering operation, and the first boom control valve 16 is positioned at the first region Y1 when neither a machine body lifting operation nor the sudden operation is performed during the boom-lowering operation, and at the region Y2 when the machine body lifting operation or the sudden operation is performed.

Provided is a construction vehicle including: a rolling-use hydraulic pump coupled to an output shaft of an engine and supplying hydraulic oil to a rolling-use hydraulic circuit; a task-use hydraulic pump coupled to the output shaft of the engine and supplying the hydraulic oil to a task-use hydraulic circuit; and an overspeed suppression mechanism configured to activate the task-use hydraulic pump to suppress overspeed of the engine when a load equal to or greater than allowable rotation speed is applied from the rolling-use hydraulic pump to the output shaft of the engine.

Provided is a construction machine. The construction machine includes a boom cylinder driving a boom, a rotation motor rotating a rotary body, an arm cylinder driving an arm, a bucket cylinder driving a bucket, a first main pump supplying working fluid to the boom cylinder and discharging the working fluid in opposite directions, a second main pump supplying working fluid to the rotation motor and discharging the working fluid in opposite directions, and a third main pump supplying working fluid to the arm cylinder or the bucket cylinder.