A pressure control valve has: a passageway having a flow opening; an member displaceable relative to the opening for obstructing the opening by differing amounts; a piezo actuator; and a linkage mechanism adapted to amplify a dimensional change in the piezo actuator and to use the amplified dimensional change to displace the member relative to the opening, wherein the linkage mechanism comprises a frame attached to a wall and fixed at a first end in relation to the passageway, a portion of the frame moveable in a first direction while being substantially restrained in a second direction orthogonal to the first direction, the piezo actuator extending between the wall and the movable portion such that an expansion of the piezo actuator results in movement of the movable portion in the first direction by an amount greater than the expansion of the piezo actuator, the moveable portion connected to the member.

A servo valve comprising: a fluid transfer valve assembly includes: a housing having channel therethrough fluidly connecting a supply port, a return port and a control port formed in the housing; a moveable valve spool located within the channel and arranged to regulate flow of fluid between the supply port, the return port and 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 valve spool comprises a first spool part and a second spool part and the drive assembly comprises a piezoelectric actuator positioned between the first and the second spool parts within the channel. Then when a control signal is applied to the piezoelectric actuator it causes extension or contraction of the first and second piezoelectric actuator elements.

A piezoelectric valve includes: a valve main part including a gas pressure chamber receiving compressed gas supplied from outside; a plate inside the valve main part, and an actuator fixed to the plate and inside the valve main part, which is a case with an opening on a front surface. The plate includes a gas discharge path and a valve seat coming into contact with a valve element of the actuator opening and closing the gas discharge path. A lid member that closes the opening of the case has a gas discharge opening communicating with the gas discharge path of the plate; is welded and fixed to a front surface of the plate, where the gas discharge path opens, on an annular welded part surrounding the gas discharge opening; and is welded and fixed to an end surface of the case on an annular welded part on the outer peripheral part.

A pressure control valve has: a passageway having a flow opening; an member displaceable relative to the opening for obstructing the opening by differing amounts; a piezo actuator; and a linkage mechanism adapted to amplify a dimensional change in the piezo actuator and to use the amplified dimensional change to displace the member relative to the opening, wherein the linkage mechanism comprises a frame attached to a wall and fixed at a first end in relation to the passageway, a portion of the frame moveable in a first direction while being substantially restrained in a second direction orthogonal to the first direction, the piezo actuator extending between the wall and the movable portion such that an expansion of the piezo actuator results in movement of the movable portion in the first direction by an amount greater than the expansion of the piezo actuator, the moveable portion connected to the member.

In accordance with at least one aspect of this disclosure, a flow control device can include, a first plate having one or more windows defining a flow path therethrough, a second plate configured to abut the first plate, and an actuator operatively connected to one or more of the first plate and/or the second plate. The actuator can be configured to drive the first plate and/or the second plate relative to one another to enlarge or reduce the flow path through the one or more windows in the first plate.

A servo valve comprises a first spool extending along a first spool axis, a second spool extending along a second spool axis, a first piezoelectric actuator, and a second piezoelectric actuator. The first piezoelectric actuator is operatively connected to the first spool for translating the first spool in response to a voltage applied thereto. The second piezoelectric actuator is operatively connected to the second spool for translating the second spool in response to a voltage applied thereto.

A metering valve has a closing member and a valve seat. The closing member is movable between a closed position on the valve seat sealing a material outlet, and an open position raised above the valve seat leaving the outlet clear. An actuating element rigidly connected to the closing member is arranged between first and second piezo-actuators at a distance from the first piezo-actuator in the closed position less than the maximum length change of the first piezo-actuator, or lies loosely thereon and at a distance from the second piezo-actuator longer than the maximum length change of the first piezo-actuator. The actuating element in the open position is arranged at a distance from the second piezo-actuator less than the maximum length change of the second piezo-actuator, or lies loosely thereon and at a distance from the first piezo-actuator greater than the maximum length change of the second piezo-actuator.

In an optical sorter that includes an optical detection unit to detect a to-be-sorted material at a detection position, a determining unit to determine a to-be-sorted material to be removed, based on a detection result by the optical detection unit, and an air-jetting unit to blow off and remove the to-be-sorted material to be removed using jet air of a compressed gas, based on a determination result by the determining unit, the air-jetting unit includes a piezoelectric valve to perform valve opening and closing by driving a valve disc utilizing displacement of a piezoelectric element, and a valve driving unit to apply a drive voltage to the piezoelectric element, and the valve driving unit controls the drive voltage applied to the piezoelectric element in accordance with the to-be-sorted material to be removed to thus control a jet-air pressure of the compressed gas for removing the to-be-sorted material.

A hydraulic servo valve comprising a pair of opposing receiving ports, a piston disposed between the pair of opposing receiving ports and an actuator in contact with the piston. The actuator is configured to provide axial movement of the piston in response to being actuated. The piston comprises a pair of opposed openings that are in operable fluid communication with a respective one of each of the receiving ports, and the axial movement of the piston is configured to vary the amount of a fluid pressure communicated between a respective one of the openings and receiving ports.

A metering valve has a closing member and a valve seat. The closing member is movable between a closed position on the valve seat sealing a material outlet, and an open position raised above the valve seat leaving the outlet clear. An actuating element rigidly connected to the closing member is arranged between first and second piezo-actuators at a distance from the first piezo-actuator in the closed position less than the maximum length change of the first piezo-actuator, or lies loosely thereon and at a distance from the second piezo-actuator longer than the maximum length change of the first piezo-actuator. The actuating element in the open position is arranged at a distance from the second piezo-actuator less than the maximum length change of the second piezo-actuator, or lies loosely thereon and at a distance from the first piezo-actuator greater than the maximum length change of the second piezo-actuator.