An electrohydraulic control valve (1) comprising a control valve element (2) displaceable in a first direction by a pressure in a first pressure chamber (5) and in a second direction by a pressure in a second pressure chamber (6). Each pressure chamber (5, 6) is connected to a line between a high pressure port (PP) and a low pressure port (PT) via a magnetic valve (11, 12). Each magnetic valve (11, 12) is a three-way valve and comprises a first valve seat (17) and a second valve seat (18). A space (19) between the first valve seat (17) and the second valve seat (18) is connected to the pressure chamber (5, 6) and a first valve element (20) positioned outside the space (19) cooperates with the first valve seat (17) and a second valve element (21) positioned outside the space (19) cooperates with the second valve seat (18).

Embodiments of a directional valve assembly that provides a single device with functionality of a two-position design for automated operation and functionality of a three-position design for manual operation. The embodiments can include a housing with a piston chamber and a spool member that transits in the housing to regulate the flow of a working fluid to a cylinder. The embodiments can also have one or more pilot operators that regulate the flow of pilot air into the piston chamber to move the spool member between two positions, i.e., two open positions. The embodiments can also have a manual operator (e.g., a lever) that can move the spool to the open positions and to a closed position. In one embodiment, the spool member is configured to remain in either a first position, a second position, or a third position in the absence of an outside stimulus on the pilot operators.

An electromagnetic valve includes a valve casing, which has a valve hole, a spool valve in the valve hole, first and second output ports each communicating with the valve hole, first and second pressure introduction holes, which respectively communicate with the first and second output ports, first and second pressure sensors, which is respectively fitted in the first and second pressure introduction holes, sealing members, which are arranged between the respective pressure sensors and the pressure introduction holes, first and second substrates, on which the corresponding first and second pressure sensors are mounted, and a housing, which accommodates the first and second substrates, has the first and second pressure introduction holes, and is attached to the valve casing. The first and second substrates are arranged to be opposed to each other in a state of being upright in a direction perpendicular to the movement direction of the spool valve.

A servovalve includes: a fluid transfer valve assembly comprising a supply port and a control port; a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive assembly comprises a piezoelectric actuator configured to vary the flow of fluid to respective ends of the valve spool in response to the control signal.

A proportional valve is provided having a pilot control valve that can be controlled by means of a control signal and having a booster valve that can be actuated by means of the pilot control valve. The proportional valve has a compressed-air connection for connecting a compressed-air supply, a working connection, and an air-removal connection. The booster valve has three valve elements, which are arranged one after the other and can each be moved in an axial direction against a spring force.

A servovalve includes a fluid transfer valve assembly comprising a supply port and a control port and a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal. The servovalve also includes a jet pipe assembly configured to direct fluid to the ends of the spool to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The jet pipe assembly comprises a jet pipe a connector header fluidly connecting the jet pipe to a nozzle. The spool has one or more openings 28 is provided in the spool such that fluid from the supply port flows into the interior of the spool and into the jet pipe.

A hydraulic valve with electropneumatic activation includes an air inlet that receives pressurized air from an air compressor and directs it into a line of the cylinder. The line is connected to an extension line attached to a solenoid extension valve that allows or blocks the passage of pressurized air from the extension line to a rear line. The rear line is attached to the rear chamber of the cylinder and connected to a retraction line attached to a solenoid retraction valve that allows or blocks the passage of pressurized air from the retraction line to an anterior line, which is attached to the front chamber of the cylinder. Thus, the passage of pressurized air is managed according to the desired movement of the stem of the hydraulic actuator. The pneumatic tubes are eliminated and electropneumatic valves are replaced by solenoid valves incorporated into the cylinder of the hydraulic valve.

A main spool (24) has a throttle passage (30) that, when the main spool (24) moves to an axial other side against a first return spring (21) in a main spool insertion hole (13), communicates a pilot pressure chamber (25) with a first tank port (15) and limits a flow amount of hydraulic oil to be discharged to the first tank port (15) from the pilot pressure chamber (25). When the main spool (24) moves to the axial other side along the main spool insertion hole (13), the throttle passage (30) communicates the pilot pressure chamber (25) with the first tank port (15) before a state where a first pump port (17) is communicated with an output port (16) and a state where the output port (16) is blocked from the first tank port (15).

A control valve for an automatic transmission includes a valve body and a solenoid module. The body has a chamber, control pressure port, exhaust port, and reference surface. Metering edges are formed in the body at the control port. A spring transmits force between first and second spools in the chamber. The solenoid module has a pin for displacing the first spool and is located by contact with the reference surface. The solenoid module also has a first stop surface limiting pin movement and a second stop surface contacting the reference surface.

An electromagnetic valve includes a valve casing, which has a valve hole, a spool valve in the valve hole, first and second output ports each communicating with the valve hole, first and second pressure introduction holes, which respectively communicate with the first and second output ports, first and second pressure sensors, which is respectively fitted in the first and second pressure introduction holes, sealing members, which are arranged between the respective pressure sensors and the pressure introduction holes, first and second substrates, on which the corresponding first and second pressure sensors are mounted, and a housing, which accommodates the first and second substrates, has the first and second pressure introduction holes, and is attached to the valve casing. The first and second substrates are arranged to be opposed to each other in a state of being upright in a direction perpendicular to the movement direction of the spool valve.