A four-position switching valve includes first and second pistons for driving a spool in a valve body, and a spool moving mechanism part that moves the spool to first and second intermediate switching positions between one-end side and the other-end-side switching positions. The spool moving mechanism part includes a compression spring that moves the spool back in the opposite direction by moving to the switching position on one end side and the other end side of the spool. The compression spring moves the spool to the first intermediate switching position when the spool moves to one-end-side switching position and the pressure on the second piston is released, and moves the spool to the second intermediate switching position when the spool moves to the other-end-side switching position and the pressure on the first piston is released.

The disclosure relates to a sensor cleaning system for a vehicle having: at least one sensor cleaning module, wherein the sensor cleaning module has a valve unit, wherein the valve unit is configured for receiving compressed air via a module compressed air port and for selectively outputting the compressed air cleaning pulse via a cleaning compressed air port. The sensor cleaning module has a module reservoir and a pump mechanism, wherein the module reservoir is configured for receiving and storing the cleaning liquid provided via a module liquid port, and is connected to the pump mechanism for fluid transfer, and the pump mechanism is configured for providing the cleaning liquid in the form of a liquid cleaning pulse at a cleaning fluid port depending on a control signal.

A cleaning device for a vehicle provides a liquid cleaning pulse and/or a compressed air cleaning pulse for a cleaning nozzle. The cleaning device includes a module compressed air connection for receiving compressed air and a pressure cylinder with a cylinder volume. A movable separator divides the cylinder volume into a compressed air receiving chamber and a cleaning liquid receiving chamber in a fluid tight manner. The air chamber has an air chamber connection which can be supplied with compressed air. Contraction of the liquid chamber occurs when filling the air chamber by moving the separator against a restoring force. A switching valve establishes a pneumatic connection between the module compressed air connection and the air chamber connection. A bypass valve establishes a pneumatic connection between the module compressed air connection and the compressed air nozzle line while bypassing the switching valve for providing a bypass compressed air flow.

A cleaning device for a vehicle provides a liquid cleaning pulse and/or a compressed air cleaning pulse for a cleaning nozzle. The cleaning device includes a module compressed air connection for receiving compressed air and a pressure cylinder with a cylinder volume. A movable separator divides the cylinder volume into a compressed air receiving chamber and a cleaning liquid receiving chamber in a fluid tight manner. The air chamber has an air chamber connection which can be supplied with compressed air. Contraction of the liquid chamber occurs when filling the air chamber by moving the separator against a restoring force. A switching valve establishes a pneumatic connection between the module compressed air connection and the air chamber connection. A bypass valve establishes a pneumatic connection between the module compressed air connection and the compressed air nozzle line while bypassing the switching valve for providing a bypass compressed air flow.

An example valve assembly includes a first workport fluidly coupled to a first actuator; a second workport fluidly coupled to the first actuator; a third workport fluidly coupled to a second actuator, wherein the third workport is fluidly coupled to the first workport via a first fluid passage; a fourth workport fluidly coupled to the second actuator, wherein the fourth workport is fluidly coupled to the second workport via a second fluid passage; and a spool axially movable in a bore within the valve assembly, wherein when the spool is shifted axially in a first axial direction, pressurized fluid is provided to the first workport and to the third workport via the first fluid passage, and when the spool is shifted axially in a second axial direction opposite the first axial direction, pressurized fluid is provided to the second workport and to the fourth workport via the second fluid passage.

An example valve assembly includes a first workport fluidly coupled to a first actuator; a second workport fluidly coupled to the first actuator; a third workport fluidly coupled to a second actuator, wherein the third workport is fluidly coupled to the first workport via a first fluid passage; a fourth workport fluidly coupled to the second actuator, wherein the fourth workport is fluidly coupled to the second workport via a second fluid passage; and a spool axially movable in a bore within the valve assembly, wherein when the spool is shifted axially in a first axial direction, pressurized fluid is provided to the first workport and to the third workport via the first fluid passage, and when the spool is shifted axially in a second axial direction opposite the first axial direction, pressurized fluid is provided to the second workport and to the fourth workport via the second fluid passage.

A piezoelectric ring bender servo valve assembly reduces mechanical wear by removing mechanical components used in prior art servo valves. The assembly does not use torque motor, flapper, and feedback spring. In this manner, no moving parts are required, which reduces maintenance and costs. A pair of piezoelectric ring benders mount adjacently to a pair of nozzles. The piezoelectric ring benders independently regulate the flow of fluid through the nozzles by moving between an open position to enable flowage, and a closed position to restrict flowage. A linear position sensing device measures and provides feedback about the spool position to a valve controller. The valve controller allows the spool valve to move until valve position achieves command position and the force on the spool valve is in equilibrium with pressure difference across spool valve. An H-bridge operable to switch the polarity of a differential pressure applied across to a load.

A piezoelectric ring bender servo valve assembly reduces mechanical wear by removing mechanical components used in prior art servo valves. The assembly does not use torque motor, flapper, and feedback spring. In this manner, no moving parts are required, which reduces maintenance and costs. A pair of piezoelectric ring benders mount adjacently to a pair of nozzles. The piezoelectric ring benders independently regulate the flow of fluid through the nozzles by moving between an open position to enable flowage, and a closed position to restrict flowage. A linear position sensing device measures and provides feedback about the spool position to a valve controller. The valve controller allows the spool valve to move until valve position achieves command position and the force on the spool valve is in equilibrium with pressure difference across spool valve. An H-bridge operable to switch the polarity of a differential pressure applied across to a load.

Servo-valve that controls fluid discharged from a nozzle discharge port by displacing the nozzle, and that drives an actuator. The servo-valve includes a receiver having an inflow surface provided with a first inflow port, and a second inflow port into which fluid discharged from the discharge port flows. The nozzle includes a force generation portion having an end surface provided with the discharge port, and an outer circumferential surface formed on the periphery of the end surface. Displacing the nozzle from neutral position toward the first inflow port blows the fluid inside the second inflow port out toward the nozzle. The force generation portion collides with the fluid blown out from the second inflow port, causing assisting force in a direction matching the direction of nozzle displacement toward the first inflow port. The nozzle easily moves by the assisting force generated in the force generation portion, improving response speed.

Servo-valve that drives an actuator by using a fluid. The servo-valve includes a nozzle having a discharge edge forming an outline of a discharge port from which the fluid is discharged and a tapered inner wall growing narrower toward the discharge edge, and a receiver that is provided with a flow path into which the fluid discharged from the discharge port flows. The nozzle is displaced in a direction different from the fluid discharge direction. The flow path extension direction is inclined with respect to a direction orthogonal to an inflow surface facing the nozzle by an angle α. A taper angle determined by the tapered inner wall is larger than twice the angle α. With such a configuration, the component of flow force exerted from the fluid on the tapered inner wall decreases. Since the nozzle can be quickly displaced, response speed of the actuator is improved.