Piezoelectric Valve

Abstract

To provide a piezoelectric valve capable of preventing damage by shock in contact and operation failure because of contact without causing a valve seat plate to swing and abut on an inner surface of a body case.SOLUTION: A piezoelectric valve includes an actuator for driving a valve body, and a valve seat and a discharge path allowed to contact and separate from the valve body, and then a valve seat plate for fixing the actuator, and a body case for housing the valve seat plate. In the piezoelectric valve, the actuator includes: a valve body; a piezoelectric element for generating drive force required for operating the valve body as displacement; and a displacement enlargement mechanism for enlarging displacement of the piezoelectric element and allowing it to operate on the valve body. In the piezoelectric valve in which a body case has a gas supply port for supplying a compressed gas, and a gas discharge port for discharging the compressed gas supplied from the gas supply port via a discharge path of the valve seat plate by separation of the valve body and the valve seat, the valve seat plate is fixed to the body case in a front part in a side having the discharge path and in a rear part in a side for fixing the actuator.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a piezoelectric valve that opens and closes by utilizing the displacement of a piezoelectric element. [Background technology]

[0002] BACKGROUND ART Conventionally, piezoelectric valves that use the displacement of a piezoelectric element to open and close the valve and eject compressed gas are well known, as described in Patent Documents 1 and 2, for example.

[0003] The piezoelectric valves described in Patent Documents 1 and 2 are equipped with an actuator that utilizes the characteristics of a piezoelectric element, which has excellent high-speed response performance, and the actuator is equipped with a displacement amplification mechanism that amplifies the small displacement of the piezoelectric element based on the principle of leverage.

[0004] Because the piezoelectric valve has excellent responsiveness, when it is used as an ejector valve in an optical sorting machine for granular materials such as rice grains to remove defective products, it is less likely that good products will be removed as well, and it has been found from tests and experience that the rate of defective products mixed in with the removed defective products is higher than with electromagnetic valves.

[0005] Incidentally, the piezoelectric valves described in Patent Documents 1 and 2 are housed in a case with the valve seat plate, to which the actuator is fixed, fixed to the front surface of the valve body.

[0006] However, because the piezoelectric valve has a structure in which the valve seat plate is suspended from the front of the valve body, the valve seat plate may swing and come into contact with the inner surface of the case of the valve body, which may cause damage if a strong impact is applied due to the contact, and there is also concern that the valve seat plate may not function properly if operated while in contact with the inner surface of the case. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5764049 [Patent Document 2] Patent Publication No. 2021-8892 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, the present invention aims to provide a piezoelectric valve in which the valve seat plate does not swing and come into contact with the inner surface of the main body case, preventing damage due to impact upon contact and malfunction due to contact. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides an actuator that drives the valve body; a valve seat plate having a valve seat and a discharge passage that come into contact with and separate from the valve body, and that fixes the actuator; a main body case that houses the valve seat plate, The actuator is The valve body; a piezoelectric element that generates a driving force required for the operation of the valve body as a displacement; a displacement magnifying mechanism that magnifies the displacement of the piezoelectric element and applies it to the valve body, The main body case includes: a gas supply port through which compressed gas is supplied; a gas discharge port that discharges the compressed gas supplied from the gas supply port through the discharge path of the valve seat plate by separating the valve body from the valve seat, The valve seat plate has a front portion on the side having the discharge passage and a side on which the actuator is fixed. The longitudinal direction of the piezoelectric element The rear portion of the device is fixed to the main body case.

[0010] In order to achieve the above object, the present invention provides: a plurality of actuators that individually drive the plurality of valve bodies in parallel planes; a valve seat plate having a plurality of valve seats and discharge paths that are individually connected to and separated from the plurality of valve bodies, and that fixes the plurality of actuators; a main body case that houses the valve seat plate, The plurality of actuators include: The valve body; a piezoelectric element that generates a driving force required for the operation of the valve body as a displacement; a displacement magnifying mechanism that magnifies the displacement of the piezoelectric element and applies it to the valve body, The main body case includes: a gas supply port through which compressed gas is supplied; a plurality of gas exhaust ports that individually discharge the compressed gas supplied from the gas supply port through the plurality of exhaust paths of the valve seat plate as a result of separation between the plurality of valve bodies and the plurality of valve seats, The valve seat plate has a front portion on the side having the plurality of discharge passages and a side on which the plurality of actuators are fixed. The longitudinal direction of the piezoelectric element The rear portion of the device is fixed to the main body case.

[0011] The present invention provides the main body case is a case having an open rear surface and the gas exhaust port on a front surface, The valve seat plate is provided with a cover member that closes the opening on the rear surface of the main body case, The valve seat plate has a front portion on the side having the exhaust passage, the front surface of which opens into the main body case, and is fixed to the main body case from the front by screws, and the exhaust passage communicates with the gas exhaust port of the main body case, while the side on which the actuator is fixed is The longitudinal direction of the piezoelectric element Preferably, the cover member is fixed to the main body case from the rear by screws at the rear portion to close the opening at the rear surface of the main body case.

[0012] The present invention also provides The valve seat plate is fixed to the main body case by fitting at a front portion on the side having the exhaust passage, where the front surface where the exhaust passage opens in the main body case, and the exhaust passage communicates with the gas exhaust port of the main body case, while the side where the actuator is fixed The longitudinal direction of the piezoelectric element It is preferable that the cover member be fixed to the main body case by fitting at the rear portion thereof, and close the opening at the rear surface of the main body case.

[0013] The present invention provides the main body case is a case having an open rear surface and the gas exhaust port on a front surface, The valve seat plate is provided with a cover member that closes the opening on the rear surface of the main body case, The valve seat plate has a front portion on the side having the exhaust passage, the front surface of which opens into the main body case, and is fixed to the main body case from the front by screws, and the exhaust passage communicates with the gas exhaust port of the main body case, while the side on which the actuator is fixed is The longitudinal direction of the piezoelectric element Preferably, at the rear portion, the cover is fixed to the main case from the rear by screws to close the rear opening of the main case, and both side surfaces are fixed to the main case from both sides by screws.

[0014] The present invention provides The actuator a base secured to the valve seat plate; a piezoelectric element having one end connected to the mounting surface of the base and extending in a first longitudinal direction; a support portion that is integrally provided on the base portion and extends in a second longitudinal direction that intersects with the first longitudinal direction alongside the piezoelectric element; an action portion connected to the other end of the piezoelectric element and the tip end of the support portion, and displaced in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction in accordance with expansion and contraction of the piezoelectric element; the valve body is provided on the side of the action portion in the direction of displacement and is driven by the displacement of the action portion, It is preferable that the displacement magnifying mechanism includes the support portion and the action portion.

[0015] The present invention provides The valve seat plate is provided with electrodes for connecting lead wires of the piezoelectric element, and is molded with wiring pins for supplying power to the piezoelectric element, It is preferable that one end of the wiring pin is connected to the electrode and the other end extends rearward from the rear surface of the lid.

[0016] The present invention provides It is preferable that the electrode, in a state where it is connected to the lead wire of the piezoelectric element and the wiring pin, be covered with an insulating material together with one end of the wiring pin.

[0017] The present invention provides The insulating material is preferably an insulating resin material such as silicone.

[0018] The present invention provides A cover member is preferably fixed to the lid of the valve seat plate, surrounding the other end of the wiring pin extending rearward from the rear surface of the lid and constituting a wiring connector together with the other end of the wiring pin.

[0019] The present invention provides It is preferable that the cover member be fixed to the lid material of the valve seat plate by screws. The present invention also provides It is preferable that the cover member be fixed to the lid material of the valve seat plate by fitting. In the present invention, the cover member may be fixed to the lid material of the valve seat plate by screws or fitting.

[0020] The present invention provides It is preferable that nuts for fixing the valve seat plate to the main body case with screws, the electrodes, and the wiring pins are insert molded together with the valve seat plate.

[0021] The present invention provides The front surface of the valve seat plate is fixed to the front inner surface of the main body case, and the valve seat plate It is preferable that the portion where the exhaust path communicates with the gas exhaust port of the main body case is sealed with a packing, and the portion where the cover material of the valve seat plate closes the opening on the rear surface of the main body case is sealed with an O-ring. [Effects of the Invention]

[0022] The piezoelectric valve of the present invention is a piezoelectric valve comprising an actuator for driving a valve body, a valve seat plate having a valve seat and a discharge passage that are adapted to come into contact with and separate from the valve body and for fixing the actuator, and a main body case for accommodating the valve seat plate, wherein the valve seat plate has a front portion on the side having the discharge passage and a side on the side fixing the actuator. The longitudinal direction of the piezoelectric element Since the rear portion of the valve seat plate is fixed to the main body case, the valve seat plate does not swing and come into contact with the inner surface of the main body case. Therefore, the piezoelectric valve of the present invention can prevent damage caused by the impact when the valve seat plate comes into contact with the inner surface of the main body case, and can prevent malfunctions caused by such contact.

[0023] The piezoelectric valve of the present invention is a piezoelectric valve comprising: a plurality of actuators that drive a plurality of valve bodies individually within parallel planes; a valve seat plate that has a plurality of valve seats and discharge passages that individually come into contact with and separate from the plurality of valve bodies and that fixes the plurality of actuators; and a main body case that houses the valve seat plate, wherein the valve seat plate has a front portion on the side having the plurality of discharge passages and a side on which the plurality of actuators are fixed. The longitudinal direction of the piezoelectric element Since the rear portion of the valve seat plate is fixed to the main body case, the valve seat plate does not swing and come into contact with the inner surface of the main body case. Therefore, the piezoelectric valve of the present invention can prevent damage caused by the impact when the valve seat plate comes into contact with the inner surface of the main body case, and can prevent malfunctions caused by such contact.

[0024] In the piezoelectric valve of the present invention, the main body case is a case having an opening at the rear and the gas discharge port at the front, the valve seat plate is provided with a cover material that closes the opening at the rear of the main body case, the valve seat plate is fixed to the main body case from the front by screws at the front part on the side having the discharge path, the front face where the discharge path opens in the main body case, the discharge path communicates with the gas discharge port of the main body case, and the side on which the actuator is fixed The longitudinal direction of the piezoelectric element At the rear, the cover material is fixed to the main case from the rear with screws, closing the opening on the rear surface of the main case, making it possible to disassemble the case by removing the screws, and making it possible to investigate the cause of any malfunctions and to carry out repairs.

[0025] In the piezoelectric valve of the present invention, the main body case is a case having an opening at the rear and the gas discharge port at the front, the valve seat plate is provided with a cover material that closes the opening at the rear of the main body case, the valve seat plate is fixed to the main body case from the front by screws at the front part on the side having the discharge path, the front face where the discharge path opens in the main body case, the discharge path communicates with the gas discharge port of the main body case, and the side on which the actuator is fixed The longitudinal direction of the piezoelectric element At the rear, if the lid material is fixed to the main case from the rear with screws, closing the opening on the rear of the main case, and both side surfaces are fixed to the main case from both sides with screws, the case can be disassembled by removing the screws, making it possible to investigate the cause of a malfunction and to repair it, and by keeping the bulge in the width direction of the main case small, it becomes possible to prevent malfunctions when multiple piezoelectric valves are used in parallel as ejector valves of an optical sorting machine, etc.

[0026] In the piezoelectric valve of the present invention, an electrode for connecting the lead wire of the piezoelectric element is provided on the valve seat plate, and a wiring pin for supplying power to the piezoelectric element is molded into the valve seat plate.One end of the wiring pin is connected to the electrode and the other end extends rearward from the rear surface of the cover material, so that the wiring connector can be provided at the rear of the main body case, making it possible to make the valve smaller than conventional piezoelectric valves in which the wiring connector is provided at the side of the main body case.

[0027] In the piezoelectric valve of the present invention, if the electrode is covered with an insulating material along with one end of the wiring pin while connected to the lead wire of the piezoelectric element and the wiring pin, this, together with the wiring pin being molded into the valve seat plate, can prevent short circuits caused by water droplets, etc.

[0028] In the piezoelectric valve of the present invention, by fixing a cover member to the cover material of the valve seat plate, which surrounds the other end of the wiring pin extending rearward from the rear surface of the cover material and which, together with the other end of the wiring pin, forms a wiring connector, the wiring connector can be provided at the rear of the main body case, making it possible to make the valve smaller than conventional piezoelectric valves in which the wiring connector is provided at the side of the main body case.

[0029] The piezoelectric valve of the present invention can be easily assembled by insert molding the nuts for fixing the valve seat plate to the main body case with screws, the electrodes, and the wiring pins together with the valve seat plate.

[0030] In the piezoelectric valve of the present invention, the front surface of the valve seat plate is fixed to the front inner surface of the main body case, plate By sealing the portion where the exhaust path communicates with the gas exhaust port of the main body case with a packing, and sealing the portion where the cover material of the valve seat plate closes the opening on the rear surface of the main body case with an O-ring, gas leakage from the main body case can be prevented. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view of a piezoelectric valve. [Figure 2] FIG. 2 is a front view of the piezoelectric valve of FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 6 is a front view of the valve seat plate of FIG. 5. [Figure 7] FIG. 6 is a side view of the valve seat plate of FIG. 5. [Figure 8] FIG. 10 is a perspective view of the valve seat plate with the actuator fixed thereto. [Figure 9] FIG. 9 is a front view of the valve seat plate of FIG. 8. [Figure 10] FIG. 9 is a side view of the valve seat plate of FIG. 8. [Figure 11] FIG. 9 is a bottom view of the valve seat plate of FIG. 8. [Figure 12] FIG. 1 is an exploded view of a piezoelectric valve. DETAILED DESCRIPTION OF THE INVENTION

[0032] An embodiment of the present invention will be described with reference to the drawings. Figure 1 shows a perspective view of a piezoelectric valve. Figure 2 shows a front view of the piezoelectric valve of Figure 1. Figure 3 shows a perspective view of the valve body. In the embodiment of the present invention, the piezoelectric valve 1 comprises a valve body 2, an actuator 3 (described later), and a valve seat plate 4 (described later) disposed inside the valve body 2 with the actuator 3 fixed thereto.

[0033] The valve body 2 is a case with an open rear surface (bottom surface in Figures 1 to 3), and is provided with a gas pressure chamber inside that receives a supply of compressed gas from an external compressed gas supply source (not shown). In addition, a connector portion (not shown) is provided on the front surface (top surface in Figures 1 to 3) of the valve body 2 for attachment to a manifold (not shown) having a space inside to which compressed gas is supplied from a compressed gas source.

[0034] A gas inlet port for drawing compressed gas into the valve body 2 and a plurality of gas outlet ports for discharging the compressed gas are open on the front surface of the connector portion. Furthermore, a gas supply port 21 communicating with the gas inlet port of the connector portion, and a plurality of gas outlet ports 22 communicating with the gas outlet ports of the connector portion are opened on the front surface of the valve body 2. As shown in FIGS. 1 and 2, a cover body 6 is attached to the rear surface of the valve body 2, and a wiring connector for supplying power to a piezoelectric element 32 (described later) is formed on the rear surface of the cover body 6.

[0035] FIG. 4 shows a perspective view of the actuator. The actuator 3 includes a base 31 fixed to a valve seat plate 4 described later, a piezoelectric element 32 having one end connected to the mounting surface of the base 31 and extending in a first longitudinal direction, and a support part 33 formed integrally with the base 31 and extending alongside the piezoelectric element 32 in a second longitudinal direction intersecting the first longitudinal direction.

[0036] The actuator 3 includes an action portion 34 connected to the other end of the piezoelectric element 32 and the tip end of the support portion 33, and displaced in a direction different from each of the first longitudinal direction and the second longitudinal direction as the piezoelectric element 32 expands and contracts, and a valve body 35 provided on one side of the action portion 34 at the tip end thereof in the direction of displacement, and driven by the displacement of the action portion 34.

[0037] The base portion 31 is fixed to the valve seat plate 4 with a screw by utilizing the mounting hole 381 on at least the side where the support portion 33 is integrally provided.

[0038] In addition, the support portion 33 has a constricted portion 331 in the middle portion extending in the second longitudinal direction, and is fixed to the valve seat plate 4 with a screw using an attachment hole 382 provided on the base portion 31 side of the constricted portion 331.

[0039] The actuator 3 is the piezoelectric element 32 The piezoelectric element 32 includes the support portion 33 and the acting portion 34 as a displacement magnifying mechanism that magnifies the displacement of the piezoelectric element 32 and acts on the valve body 35, and as the piezoelectric element 32 expands and contracts, the acting portion 34 displaces in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction within a plane approximately parallel to a plane including the first longitudinal direction and the second longitudinal direction. In this case, by providing the constricted portion 331 in the middle portion of the support portion 33 extending in the second longitudinal direction, the displacement of the action portion 34 accompanying the expansion and contraction of the piezoelectric element 32 can be increased.

[0040] Here, the base portion 31 and the support portion 33 can be integrally formed by punching out a metal material such as stainless steel including Invar. If the base portion 31 and the support portion 33 are integrally formed by stamping out a metal material, the number of parts can be reduced, and the assembly of the actuator 3 becomes easier.

[0041] Furthermore, the base 31 and the support 33 may be formed as separate members, and the support 33 may be attached to the base 31 as a separate member, so that the support 33 is provided integrally with the base 31 .

[0042] A connecting member (not shown) made of, for example, an aluminum block can be attached to the mounting surface of the base 31 . By attaching a connecting member made of a material with a larger linear expansion coefficient than the support portion 33 to the mounting surface of the base portion 31 and attaching the piezoelectric element 32 to the base portion 31 via the connecting member, the effects of thermal expansion or thermal contraction of the piezoelectric element 32 due to temperature changes can be reduced or eliminated. The connecting member can also be attached between the piezoelectric element 32 and the action portion 34 instead of to the attachment surface of the base portion 31 .

[0043] The action portion 34 can be made of a lightweight material such as aluminum, etc. Making the action portion 34 of a lightweight material such as aluminum is preferable in terms of displacing the action portion 34. The valve body 35 is made of rubber, preferably a lubricating rubber.

[0044] The actuator 3 can be configured such that a compression member 36 connects the base portion 31 and the working portion 34 . Piezoelectric elements are easily damaged by loads in the tensile direction, but by connecting the base 31 and the acting portion 34 with the compression member 36, the piezoelectric element 32 can be compressed in the first longitudinal direction, thereby preventing damage to the piezoelectric element 32.

[0045] Figure 5 shows a perspective view of the valve seat plate. Figure 6 shows a front view of the valve seat plate of Figure 5. Figure 7 shows a side view of the valve seat plate of Figure 5. 5 is an example of a valve seat plate that can mount four actuators. The valve seat plate 4 has a valve seat portion 41 in the center, and two valve seats 42, against which the valve body 35 of the actuator 3 abut, are provided on each of the opposing sides of the valve seat portion 41.

[0046] On one side of the valve seat plate 4, mounting portions 43, 43 for the actuator 3 are formed at positions facing both sides of the valve seat portion 41, respectively. Also on the other surface of the valve seat plate 4, mounting portions 44 for the actuator 3 are formed at positions facing both surfaces of the valve seat portion 41, respectively.

[0047] As shown in Figure 7, the valve seat portion 41 is formed with a plurality of discharge passages 45, one end of which opens into the valve seat surface of each valve seat 42, and the other end of each discharge passage 45 opens into the front surface of the valve seat plate 4 (the upper surface in Figures 5 to 7). Furthermore, the valve seat plate 4 is integrally provided with a cover member 46 that closes the opening on the rear surface of the valve body 2.

[0048] Figure 8 shows a perspective view of the valve seat plate with the actuator fixed. Figure 9 shows a front view of the valve seat plate of Figure 8. Figure 10 shows a side view of the valve seat plate of Figure 8. Figure 11 shows a bottom view of the valve seat plate of Figure 8. In this embodiment of the present invention, the valve bodies 35 of the four actuators 3 are arranged to face the respective valve seats 42 relative to the respective mounting portions 43, 44 of the valve seat plate 4, and the respective actuators 3 are fixed to the valve seat plate 4 with screws.

[0049] An electrode 47 for connecting a lead wire (not shown) of the piezoelectric element 32 of the actuator 3 is provided at a rear position (lower position in FIGS. 8 to 10) of the valve seat plate 4. Furthermore, a wiring pin 48 for supplying power to the piezoelectric element 32 is molded at a rear position of the valve seat plate 4. The rear end of the valve seat plate 4 is integrally provided with the cover material 46 that closes the opening in the rear surface of the case of the valve body 2, and one end of the wiring pin 48 is connected to the electrode 47, and the other end extends rearward from the rear surface of the cover material 46 (the bottom surface in Figures 8 to 10).

[0050] Here, the electrode 47, while connected to the lead wire of the piezoelectric element 32 and the wiring pin 48, can be covered together with one end side of the wiring pin 48 with an insulating material, for example, an insulating resin material such as silicone. If the electrode 47 is covered with an insulating material together with one end of the wiring pin 48 while connected to the lead wire of the piezoelectric element 32 and the wiring pin 48, then, in addition to the wiring pin 48 being molded into the valve seat plate 4, it is possible to prevent short circuits caused by water droplets, etc.

[0051] Figure 12 shows an exploded view of the piezoelectric valve. In an embodiment of the present invention, the piezoelectric valve 1 can be assembled by inserting the valve seat plate 4, to which the actuator 3 is fixed, into the case through the opening on the rear surface of the valve body 2, closing the opening on the rear surface of the valve body 2 with the lid member 46 attached to the valve seat plate 4, and fixing the cover body 6 to the rear surface of the lid member 46.

[0052] The valve seat plate 4 is fixed to the valve body 2 from the front with screws 71, 71 at the front part on the side having the exhaust passage 45, where the exhaust passage 45 opens inside the case of the valve body 2, and the exhaust passage 45 communicates with the gas exhaust port 22 of the valve body 2.

[0053] In addition, the valve seat plate 4 has the cover member 46 fixed to the valve body 2 from the rear by screws 72, 72 at the rear portion on the side where the actuator 3 is fixed, thereby closing the opening on the rear surface of the valve body 2.

[0054] At this time, the front surface of the valve seat plate 4 is fixed to the front inner surface of the valve body 2, and the valve seat plate The portion where the exhaust path 45 of the valve seat plate 4 communicates with the gas exhaust port 22 of the valve body 2 is sealed with a packing 75, and the portion where the cover material 46 of the valve seat plate 4 closes the opening on the rear surface of the valve body 2 is sealed with an O-ring 76, thereby preventing gas leakage from the valve body 2.

[0055] Then, the cover body 6 that surrounds the other end of the wiring pin 48 extending rearward from the rear surface of the cover material 46 of the valve seat plate 4 and forms a wiring connector together with the other end of the wiring pin 48 is fixed to the rear surface of the cover material 46 of the valve seat plate 4 with screws 74 or the like.

[0056] In the piezoelectric valve 1 according to the embodiment of the present invention, when current is applied to the piezoelectric element 32 of the actuator 3 in the closed state, the piezoelectric element 32 expands, the action portion 34 is displaced, and the valve body 35 moves away from the valve seat 42 to open the valve, and the compressed gas supplied from the gas supply port to the valve body 2 is discharged from the gas discharge port 22 opening at the front surface of the valve body 2 via the discharge path 45 formed in the valve seat portion 41 of the valve seat plate 4. On the other hand, when the power supply to the piezoelectric element 32 of the actuator 3 is released, the piezoelectric valve 1 contracts, the operating part 34 is displaced in the opposite direction, and the valve body 35 seats on the valve seat 42 to close the valve.

[0057] In the piezoelectric valve 1 according to the embodiment of the present invention, the valve seat plate 4 is fixed to the valve body 2 at the front end on the side having the discharge passage and at the rear end on the side on which the actuator is fixed, so that the valve seat plate 4 does not swing and come into contact with the inner surface of the valve body 2. Therefore, the piezoelectric valve according to the embodiment of the present invention can prevent damage caused by the impact when the valve seat plate 4 comes into contact with the inner surface of the valve body 2, and can prevent malfunctions caused by such contact.

[0058] Furthermore, in the piezoelectric valve 1 according to the embodiment of the present invention, the valve seat plate 4 is fixed from the front to the valve body 2 with screws 71, 71 at the front part on the side having the discharge channel 45, where the front surface where the discharge channel 45 opens within the case of the valve body 2, and the cover material 46 is fixed from the rear to the valve body 2 with screws 72, 72 at the rear part on the side where the actuator is fixed. This makes it possible to disassemble the valve by removing the screws, making it possible to investigate the cause of a malfunction and to carry out repairs.

[0059] In the piezoelectric valve 1 according to the embodiment of the present invention, a cover body 6 which constitutes a wiring connector together with the other end of the wiring pin 48 is fixed to the rear surface of the lid member 46 of the valve seat plate 4, so that the wiring connector can be provided at the rear of the valve body 2. This makes it possible to make the piezoelectric valve 1 smaller than conventional piezoelectric valves in which the wiring connector is provided at the side of the valve body 2.

[0060] In the piezoelectric valve 1 according to the embodiment of the present invention, the valve seat plate 4 can be fixed at both sides to the valve body 2 by screws 73, 73 at the rear portion on the side where the actuator 3 is fixed, as shown in FIGS. 1 and 12. If the valve seat plate 4 is fixed to the valve body 2 on both sides with screws 73, 73 at the rear part on the side where the actuator 3 is fixed, the bulge in the width direction of the case of the valve body 2 can be kept small, thereby preventing malfunctions when multiple piezoelectric valves 1 are used in parallel as ejector valves of an optical sorting machine, etc.

[0061] In this embodiment of the present invention, the nuts for screwing the valve seat plate 4 to the valve body 2, the electrodes 47, and the wiring pins 48 can be insert molded together with the valve seat plate 4. If the nuts for screwing the valve seat plate 4 to the valve body 2, the electrodes 47, and the wiring pins 48 are insert molded together with the valve seat plate 4, assembly of the piezoelectric valve becomes easy.

[0062] In the above-described embodiment of the present invention, the valve seat plate 4 is fixed to the case of the valve body 2 from the front by screws 71, 71 at the front surface where the discharge passage 45 opens within the case of the valve body 2, and the cover material 46 is fixed to the case of the valve body 2 from the rear by screws 72, 72. However, by fixing the parts by fitting them together, they can be disassembled, which makes it possible to investigate the cause of a malfunction and to make repairs.

[0063] In the example shown in FIG. 1, the multiple gas discharge ports 22 opening on the front surface of the valve body 2 are not aligned in a row in the thickness-width direction of the valve body 2. However, by using, for example, an intermediate member or the like having multiple flow paths therein that communicate with the openings of the gas discharge ports 22 on one surface and open in a row on the other surface, the multiple gas discharge ports opening on the front surface of the connector portion (not shown) can be aligned in a horizontal row.

[0064] In the above embodiment of the present invention, the piezoelectric valve 1 is configured so that the valve body 35 is seated on the valve seat 42 when no voltage is applied to the piezoelectric element 32. However, by changing the polarity of the voltage supplied from the drive unit, the valve body 35 can also be spaced apart from the valve seat 42 when no voltage is applied to the piezoelectric element 32.

[0065] In the above embodiment of the present invention, the piezoelectric valve 1 has a valve seat plate 4 with four actuators 3 fixed inside the valve body 2, and four gas discharge ports 22 opening on the front surface of the valve body 2, but this is not limited to this, and a valve seat plate with one or more actuators fixed to the valve body 2 can be arranged.

[0066] In the above embodiment of the present invention, an example of a valve seat plate 4 capable of mounting four actuators 3 has been described, but this is not limited to this. For example, a valve seat plate capable of mounting two actuators 3 on only one side can also be used.

[0067] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the configuration can be appropriately modified without departing from the scope of the invention. [Industrial Applicability]

[0068] The piezoelectric valve of the present invention is extremely useful because the valve seat plate does not swing and come into contact with the inner surface of the valve body, preventing damage due to impact upon contact and malfunction due to contact. [Explanation of symbols]

[0069] 1 Piezoelectric valve 2 Valve body (body case) 21 Gas supply port 22 Gas outlet 3 Actuators 31 Base 32 Piezoelectric element 33 Support part 331 Waist 34 Acting part 35 Valve body 36 Compression member 381 mounting hole 382 mounting holes 4 Valve seat plate 41 Valve seat 42 Valve seat 43 Mounting part 44 Mounting part 45 Exhaust channel 46 Lid material 47 electrode 48 wiring pins 6 Cover body (cover member) 71 screws 72 screws 73 screws 74 screws 75 Gasket 76 O-ring

Claims

1. an actuator that drives the valve body; a valve seat plate having a valve seat and a discharge passage that come into contact with and separate from the valve body, and that fixes the actuator; a main body case that houses the valve seat plate, The actuator is The valve body; a piezoelectric element that generates a driving force required for the operation of the valve body as a displacement; a displacement magnifying mechanism that magnifies the displacement of the piezoelectric element and applies it to the valve body, The main body case includes: a gas supply port through which compressed gas is supplied; a gas discharge port that discharges the compressed gas supplied from the gas supply port through the discharge path of the valve seat plate by separating the valve body from the valve seat, The valve seat plate is fixed to the main body case at a front portion on the side having the discharge passage and at a rear portion in the longitudinal direction of the piezoelectric element on the side where the actuator is fixed.

2. a plurality of actuators that individually drive the plurality of valve bodies in parallel planes; a valve seat plate having a plurality of valve seats and discharge paths that are individually connected to and separated from the plurality of valve bodies, and that fixes the plurality of actuators; a main body case that houses the valve seat plate, The plurality of actuators include: The valve body; a piezoelectric element that generates a driving force required for the operation of the valve body as a displacement; a displacement magnifying mechanism that magnifies the displacement of the piezoelectric element and applies it to the valve body, The main body case includes: a gas supply port through which compressed gas is supplied; a plurality of gas exhaust ports that individually discharge the compressed gas supplied from the gas supply port through the plurality of exhaust paths of the valve seat plate as a result of separation between the plurality of valve bodies and the plurality of valve seats, The valve seat plate is fixed to the main body case at a front portion on the side having the plurality of discharge paths and at a rear portion in the longitudinal direction of the piezoelectric element on the side on which the plurality of actuators are fixed.

3. the main body case is a case that is open at the rear and has the gas exhaust port at the front, The valve seat plate is provided with a cover member that closes the opening on the rear surface of the main body case, 3. The piezoelectric valve according to claim 1, wherein the valve seat plate has a front portion on a side having the exhaust passage, the front surface where the exhaust passage opens inside the main case, is fixed to the main case from the front with screws, and the exhaust passage communicates with the gas exhaust port of the main case, while the cover material is fixed to the main case from the rear with screws at a rear portion in the longitudinal direction of the piezoelectric element on the side where the actuator is fixed, thereby closing the opening on the rear surface of the main case.

4. the main body case is a case that is open at the rear and has the gas exhaust port at the front, The valve seat plate is provided with a cover member that closes the opening on the rear surface of the main body case, 4. The piezoelectric valve according to claim 3, wherein the valve seat plate has a front portion on a side having the exhaust passage, the front surface where the exhaust passage opens into the main case, fixed to the main case from the front with screws, and the exhaust passage communicates with the gas exhaust port of the main case, while the cover material is fixed to the main case from the rear with screws at a rear portion in the longitudinal direction of the piezoelectric element on the side where the actuator is fixed, closing the opening on the rear surface of the main case, and both side surfaces are fixed to the main case from both sides with screws.

5. The valve seat plate is provided with electrodes for connecting lead wires of the piezoelectric element, and is molded with wiring pins for supplying power to the piezoelectric element, 5. The piezoelectric valve according to claim 3, wherein one end of the wiring pin is connected to the electrode and the other end extends rearward from the rear surface of the lid.

6. 6. The piezoelectric valve according to claim 5, wherein the electrode is covered with an insulating material together with one end of the wiring pin in a state where the electrode is connected to the lead wire of the piezoelectric element and the wiring pin.

7. 7. The piezoelectric valve according to claim 5, wherein a cover member that constitutes a wiring connector together with the other end of the wiring pin extending rearward from the rear surface of the lid member is fixed to the lid member of the valve seat plate.

8. 8. The piezoelectric valve according to claim 5, wherein a nut for fixing the valve seat plate to the main body case with a screw, the electrode, and the wiring pin are insert-molded together with the valve seat plate.

9. The actuator is a base secured to the valve seat plate; a piezoelectric element having one end connected to the mounting surface of the base and extending in a first longitudinal direction; a support portion that is integrally provided on the base portion and extends in a second longitudinal direction that intersects with the first longitudinal direction alongside the piezoelectric element; an action portion connected to the other end of the piezoelectric element and the tip end of the support portion, and displaced in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction in accordance with expansion and contraction of the piezoelectric element; the valve body is provided on the side of the action portion in the direction of displacement and is driven by the displacement of the action portion, 9. The piezoelectric valve according to claim 1, wherein the displacement magnifying mechanism includes the support portion and the action portion.

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