The present invention provides a valve including: an inlet unit IL; an outlet unit OL perpendicular to the inlet unit; and an opening/closing unit. The opening/closing unit includes: a rod to open or close the discharge port while extending or retracting in the discharge port in a flow direction of the fluid, having a poppet to open or close the discharge port, and having a piston to be pressed by a pilot gas; a body having a guide to accommodate the rod and guide the extension and retraction of the rod, and pressing spaces into which the pilot gas is introduced; and a solenoid valve to supply the pilot gas into the pressing spaces, in which the opening/closing unit has no spring, and in which a diameter of a seat, which comes into contact with the poppet in the outlet unit, is greater than a diameter of the guide.

A bypass for an air dryer having an inlet, a prefiltration stage having a drain valve to purge contaminants, a pair of inlet valves in communication with the prefiltration stage to control the flow of compressed air through the desiccant towers, and an outlet coupled to the pair of desiccant towers. The bypass may be a bypass valve that is normally open to the outlet when the air dryer is unpowered and pilotable to be a closed to allow air to flow to the prefiltration stage when the air dryer is powered. The bypass may be a three-way valve that is normally coupled to the outlet and that may be piloted to connect to the prefiltration stage when the dryer is powered. The bypass may also be a check valve that opens in response to pressure in the inlet to allow compressed air to flow directly to the outlet.

A sleeve includes: a supply port communicated with a hydraulic oil supply source; a primary control port communicated with a retard chamber, a secondary control port communicated with an advance chamber; and a drain port communicated with an outside of a valve timing adjustment device. A spool includes: a pressure accumulation space formed at an inside of the spool; a supply passage configured to connect between the pressure accumulation space and the supply port; a primary control passage configured to connect between the pressure accumulation space and the primary control port; a secondary control passage configured to connect between the pressure accumulation space and the secondary control port; and a recycle passage configured to connect between the primary control port or the secondary control port and the pressure accumulation space. The recycle passage and the drain port are connected with each other at the inside of the sleeve.

It is made possible to suppress variations of the speed of an actuator into which a regeneration flow rate flows, regardless of variations of the regeneration flow rate caused by posture changes of the front part and to enhance the operability when the front part moves in the free fall direction, and hydraulic fluid discharged from an actuator driving the front part is regenerated. Accordingly, a controller 19 of a hydraulic system is provided with a regeneration control calculation section 19b, and a pump flow rate control calculation section 19c, and when the regeneration control calculation section controls a regeneration valve 12 to perform regeneration, the pump flow rate control calculation section controls a pump flow rate regulation device 20 to increase the delivery flow rate of a hydraulic pump 1 as the angle of an arm 16 approaches the vertically downward direction based on posture information about the arm 16 acquired by an inertial measurement unit 31.

A servo actuator is provided which may comprise a controller configured to control a plurality of solenoid valves based upon an output signal. The plurality of solenoid valves may be used to control the position of the object. For example, a set of solenoid valves, of the plurality of solenoid valves, may be configured to conduct fluid from a tank into a first chamber of the cylinder, conduct fluid from the tank into a second chamber of the cylinder, conduct fluid from the second chamber of the cylinder into a first solenoid valve and/or conduct fluid from the first chamber of the cylinder into the first solenoid valve. The first solenoid valve, of the plurality of solenoid valves, may be configured to conduct fluid from the set of solenoid valves into a vent valve based upon a pulse width modulation (PWM) signal received from the controller.

A method and control system operable to control movement of a work implement of a work vehicle. The control system includes a reservoir that retains fluid, a pump in fluid communication with the reservoir, and an actuator in fluid communication with the pump. The actuator has a first side and a second side. A control valve is fluidly positioned between the pump and the actuator, a first proportional relief valve is fluidly positioned between the pump and the first side of the actuator, and a second proportional relief valve is fluidly positioned between the pump and the second side of the actuator. The first proportional relief valve is configured to permit flow of fluid from the first side of the actuator to the reservoir when a pressure at the first side of the actuator exceeds a pressure set point.

A valve system for use with a cylinder having an extensible rod, includes first and second valve assemblies, each including an inlet/outlet port configured to selectively be coupled with a source of pressurized gas, a check valve biased toward a closed state and having a check valve body at least partially receivable within a first port of the cylinder, a flow control valve positioned in series between the inlet/outlet port and the check valve, and an inlet pilot port connected with the check valve for opening the check valve when supplied with pressurized gas. First and second pilot lines extend to the respective inlet pilot ports from respective outlet pilot ports of the opposite ones of the first and second valve assemblies. When pressurized gas is supplied to the inlet/outlet port of a valve assembly, pressurized gas is also supplied to the opposite inlet pilot port.

A valve system for use with a cylinder having an extensible rod, includes first and second valve assemblies, each including an inlet/outlet port configured to selectively be coupled with a source of pressurized gas, a check valve biased toward a closed state and having a check valve body at least partially receivable within a first port of the cylinder, a flow control valve positioned in series between the inlet/outlet port and the check valve, and an inlet pilot port connected with the check valve for opening the check valve when supplied with pressurized gas. First and second pilot lines extend to the respective inlet pilot ports from respective outlet pilot ports of the opposite ones of the first and second valve assemblies. When pressurized gas is supplied to the inlet/outlet port of a valve assembly, pressurized gas is also supplied to the opposite inlet pilot port.

An electro-hydrostatic actuating drive has a variable-volume and/or variable-speed hydraulic machine, which is driven by an electric motor, for the provision of a volumetric flow of a hydraulic fluid. Furthermore, the actuating drive comprises a cylinder with a piston, a piston rod and a first piston chamber, a valve with a first position and a second position, which valve can be moved by a first hydraulic actuator into the first position and by a second hydraulic actuator into the second position, wherein the second position controls a greater volumetric flow of the hydraulic fluid than the first position, a sink, a main line which connects a first piston chamber of the cylinder to the sink and in which the hydraulic machine is arranged, an auxiliary line which connects the first piston chamber to the sink and in which the valve is arranged, a first control line to the first hydraulic actuator, and a second control line to the second hydraulic actuator. A hydraulic resistor is arranged in the main line in series with the hydraulic machine, the first control line is connected to the main line, and the second control line is connected between the hydraulic resistor and the first piston chamber.

A compressed-air feed system for operating a pneumatic system includes a compressed-air supply, a compressed-air connection to the pneumatic system, at least one ventilation connection to surroundings, and a pneumatic main line between the compressed-air supply and the compressed-air connection. The pneumatic main line has an air dryer and a regeneration throttle. The compressed-air feed system further includes a first ventilation line between the pneumatic main line and the at least one ventilation connection. The first ventilation line has a first ventilation valve and a ventilation throttle. The compressed-air feed system additionally includes a second ventilation line between the compressed-air connection and the at least one ventilation connection. The second ventilation line has a second ventilation valve formed as a 2/2 directional valve. The compressed-air feed system is designed to provide an operating mode in which the second ventilation valve is open over a predetermined time period.