An electro-hydraulic actuator includes: a motor output rotative power; an external gear pump activated by the motor; a hydraulic actuator operated by a pressurized working fluid supplied by the external gear pump; a manifold block in which a flow channel forming a working fluid circuit of the hydraulic actuator is incorporated; a first portion to store the motor; a second portion to store the external gear pump, the hydraulic actuator, and a reservoir; and a coupling portion to couple the first portion and the second portion in a liquid-tight state. The coupling portion includes a communication hole through which the first portion and the second portion communicate, a rotational shaft of the motor and a driving shaft of the external gear pump are joined to each other, and the external gear pump is attached to the coupling portion while being stored in the manifold block.

A hydraulic system for controlling an implement on a work machine may include a hydraulic reservoir, a hydraulic pump in fluid communication with the reservoir, a central valve in fluid communication with the pump and configured for controlling the implement, a pressure relief system arranged in fluid communication with the hydraulic pump and the central valve, and a controller. The controller may be configured for controlling the hydraulic pump, the central valve and the pressure relief system and selecting between operating the hydraulic system at a first pressure and a second pressure based on a factor relating to implement position.

An exemplary valve bank and/or modular control valve having a valve body, a valve member movable in a fluid flow of the valve body to control flow of fluid, and an onboard electronic controller that is operably mounted to the valve bank or valve body. The onboard controller is operably connected to at least one actuator of the valve, which is configured to control movement of the valve member in response to commands from the onboard controller. The onboard controller may provide diagnostics, feedback and/or control of the control valve, such as via inputs from one or more sensors that may be included in the valve. The modular control valve may be used with conventional non-intelligent valve banks to thereby impart smart diagnostics and/or feedback into the valve bank in a plug-and-play manner. A communications interface may be provided in the control valve to interface and communicate with an upper-level PLC controller.

Provided is a work machine which can achieve both of excellent operability when an operator manually operates a machine body or a work device and an accuracy of control of the machine body or the work device when a controller performs automatic control. The controller is configured to, in a case where the automatic control function selector switch gives an instruction to disable the automatic control function, adjust an opening amount of a bleed-off valve to a maximum opening amount or an opening amount corresponding to input amounts of control levers, and in a case where the automatic control function selector switch gives the instruction to enable the automatic control function, adjust the opening amount of the bleed-off valve, in at least part of an operation region of the control levers, so as to be smaller than the opening amount with the instruction to disable the automatic control function being given.

Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.

An agricultural vehicle having a chassis, wheels, a power unit, and a header. The header has a center section, at least one wing section extending laterally from the center section, and a wing section support. The center section is movable relative to the chassis, the wing section is movable relative to the center section, and the wing support is movable relative to the wing section. The combine has a control system that is configured to determine that the combine is configured to drive at a road-driving speed, and in response to such determination: operate a center section actuator to move the center section to a raised center section position, operate a wing section actuator to move the wing section to a raised wing section position, and operate a wing support actuator to move the wing support to a raised wing support position.

A work machine comprises: a work implement; a hydraulic cylinder; a hydraulic pump that supplies the hydraulic oil to the hydraulic cylinder via a hydraulic circuit; a relief valve that can set a relief pressure of the hydraulic circuit to either a first set pressure or a second set pressure higher than the first set pressure; a detection unit that detects at least one of a pressure of the hydraulic oil in the hydraulic circuit and a speed of the work implement; and a relief pressure changing unit that changes a relief pressure of the relief valve from the first set pressure to the second set pressure based on a detection value of at least one of the pressure of the hydraulic oil in the hydraulic circuit and the speed of the work implement when the controlled state of the work implement is the excavation state.

A digital positioner for a valve includes a valve controller configured to obtain a set point value for a valve travel of a valve, and generate a pulse-width modulated current signal based on the set point value. The digital positioner also includes a current-to-pressure converter configured to receive the pulse-width modulated current signal from the valve controller, convert the pulse-width modulated current signal to a pulse-width modulated pressure signal, and provide the pulse-width modulated pressure signal to a pneumatic actuator in the valve to adjust a position of the valve.

Provided is a work machine that can operate a front work implement at a speed according to an operator's lever operation while securing the accuracy of work by machine control. A hydraulic excavator 1 includes a controller 20 that sets a target surface for a bucket 10 and controls the operation of a front work implement 1B in such a manner that the bucket does not penetrate to below the target surface. The controller sets a speed correction region on an upper side of the target surface, varies a width R of the speed correction region in accordance with an operation amount of an operation device 15A or 15C, and controls the operation of the front work implement in such a manner that the work tool does not penetrate into the speed correction region.

A hydropneumatic suspension system for vehicles, at least consisting of an axle suspension (10) and a cabin suspension (12), which for supplying them with pressurized fluid, can be connected to a pressure supply source, is characterized in that both the axle suspension (10) and the cabin suspension (12) can be actuated jointly by means of an control device (14), and in that, by means of a priority detection system (16) involving a sensor device (18) for the respective suspension (10, 12), the supply with pressurized fluid of the one suspension (10, 12) takes precedence depending on demand over the other suspension (12, 10).