Piezoelectric Valve

Abstract

To provide a piezoelectric valve capable of forming gas discharge ports in a row in a width direction at a front face of the valve.SOLUTION: A piezoelectric valve includes: a plurality of actuators for individually driving a plurality of valve elements; a valve seat plate having a plurality of valve seats and discharge passages individually kept into contact with and separated from each valve element; and a main body case for housing the valve seat plate. Each actuator is fixed to a side face of the valve seat plate so that each valve element is opposed to each valve seat, and detachably attached to fluid equipment through a connector portion disposed on a front face of the main body case. The valve seats are paired and disposed on both faces of the valve seat portion in a manner of being overlapped in a width direction, discharge passages formed on the paired valve seats are formed on the valve seat plate in a manner of at least partially overlapped in the width direction, a plurality of gas discharge ports are formed on the front face of the main body case not in a row in the width direction, and discharge ports of the plurality of discharge passages are formed on a front face of the connector portion in a row in the width direction.SELECTED DRAWING: Figure 1

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 a valve and eject compressed gas are well known (see Patent Documents 1 to 3).

[0003] The piezoelectric valves described in Patent Documents 1 to 3 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] When the piezoelectric valve is used as an ejector valve of the optical sorting machine, for example, as described in Patent Document 3, it is directly and continuously attached to a manifold having an internal space to which compressed air is supplied from a compressed air source, and a large number of nozzle holes are opened at the tip of the ejector.

[0006] Incidentally, the present inventors previously proposed a piezoelectric valve in which the actuator is provided with a displacement magnifying mechanism having a simple structure (see Patent Document 4). The piezoelectric valve described in Patent Document 4 has a valve seat portion in which a valve seat and a discharge passage are formed, and is equipped with a valve seat plate on both the front and back sides of the valve seat portion, with the valve seat provided on each side, and multiple actuators are fixed to both sides of the valve seat portion of the valve seat plate so that each valve body faces each valve seat.

[0007] The piezoelectric valve described in Patent Document 4 has the valve seat plate, to which the actuator is fixed, housed within a case of the valve body, and compared to the piezoelectric valves described in Patent Documents 1 to 3, the widthwise dimension when viewed from the front can be made smaller, which makes it possible to reduce the widthwise pitch of the air discharge ports opening on the front surface of the valve body.

[0008] However, in the piezoelectric valve described in Patent Document 4, when the exhaust channels opening to the valve seats on both sides of the valve seat portion of the valve seat plate are formed so as to overlap in the width direction, the exhaust channels cannot be made to open in a row in the width direction on the front surface of the valve seat plate, making it difficult to open the air exhaust ports in a row in the width direction on the front surface of the valve body. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 5764049 [Patent Document 2] Patent Publication No. 2021-8892 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-137664 [Patent Document 4] Patent application No. 2020-154308 Summary of the Invention [Problem to be solved by the invention]

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a piezoelectric valve that can open gas outlets aligned in a single row in the width direction on the front surface of the valve. [Means for solving the problem]

[0011] 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, Each of the plurality of actuators 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 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, the valve seat plate has a valve seat portion in which the valve seat and the discharge path are formed, the plurality of valve seats being provided on both the front side and the back side of the valve seat portion, the plurality of actuators are fixed to side surfaces of the valve seat plate so that the valve bodies face the respective valve seats, The main body case includes: a gas supply port through which compressed gas is supplied; a plurality of gas discharge ports that individually discharge the compressed gas supplied from the gas supply port through the plurality of discharge paths of the valve seat plate by separating the plurality of valve bodies from the plurality of valve seats, The piezoelectric valve is detachable from a fluid device via a connector provided on the front surface of the main body case, the connector portion has an intake passage, one end of which communicates with the gas supply port opening at the front surface of the main body case and the other end of which can communicate with an air supply passage formed in the fluid device, and a plurality of exhaust passages, one end of which communicates with each of the plurality of gas exhaust ports opening at the front surface of the main body case and the other end of which can communicate with each of a plurality of exhaust passages formed in the fluid device, the valve seats of the valve seat plate are provided in pairs on both surfaces of the valve seat portion so as to overlap at least partially in the width direction in a front view, the discharge passages, one end of which opens into the valve seats provided in pairs on both surfaces of the valve seat portion, are formed in the valve seat plate so as to overlap at least partially in the width direction; The other ends of the plurality of discharge channels are open on the front surface of the valve seat plate in a non-aligned manner in the width direction, The plurality of gas discharge ports are open on the front surface of the main body case in a non-linear manner in the width direction, The discharge ports of the plurality of discharge passages are open in a row in the width direction on the front surface of the connector portion.

[0012] Here, in the present invention, the "width direction" means the width direction when the piezoelectric valve is viewed from the front, unless otherwise specified.

[0013] The present invention provides It is preferable that the plurality of discharge passages of the connector portion each have a space of the same volume, and have openings of the same opening area on the front surface of the connector portion.

[0014] The present invention provides It is preferable that the plurality of gas discharge ports provided in the main body case have openings with the same opening area on the front surface of the main body case.

[0015] The present invention provides It is preferable that the multiple exhaust passages of the connector portion have an elongated hole-shaped opening on the rear surface of the connector portion, with the openings of the multiple gas exhaust ports opening on the front surface of the main body case and the exhaust ports of the multiple exhaust passages opening on the front surface of the connector portion projected onto the rear surface of the connector portion, connecting the two openings.

[0016] The present invention provides It is preferable that the fluid device is a manifold, and compressed gas supplied from a compressed gas source is supplied from the supply passage to the inside of the main body case through the intake passage of the connector portion, while compressed gas discharged from the inside of the main body case is discharged from the multiple exhaust passages through the multiple exhaust passages of the connector portion. [Effects of the Invention]

[0017] In the piezoelectric valve of the present invention, the valve seats of the valve seat plate are arranged in pairs on both sides of the valve seat portion so as to overlap at least partially in the width direction when viewed from the front, and each of the exhaust channels, one end of which opens into each of the valve seats arranged in pairs on both sides of the valve seat portion, is formed in the valve seat plate so as to overlap at least partially in the width direction, and the other ends of the multiple exhaust channels open non-aligned in the width direction on the front surface of the valve seat plate, and the multiple gas exhaust ports open non-aligned in the width direction on the front surface of the main body case, while the exhaust ports of the multiple exhaust passages open in a line in the width direction on the front surface of the connector portion.Therefore, even if the multiple gas exhaust ports do not open in a line in the width direction on the front surface of the main body case, the gas exhaust ports can be opened in a line in the width direction on the front surface of the valve.

[0018] In the piezoelectric valve of the present invention, if the multiple exhaust passages of the connector portion each have the same space volume and have openings on the front surface of the connector portion with the same opening area, various characteristics such as the amount of gas ejected from the front surface of the valve, the ejection speed, and responsiveness can be made to be approximately the same among the multiple exhaust passages, resulting in a good condition that is comparable to that when the connector portion is not provided.

[0019] The piezoelectric valve of the present invention can be used, for example, as an ejector in an optical sorting machine by being attached to the manifold, if the fluid device is a manifold in which compressed gas supplied from a compressed gas source is supplied from the supply passage to the inside of the main body case via the suction passage of the connector portion, while compressed gas discharged from the inside of the main body case is exhausted from the multiple exhaust passages via the multiple exhaust passages of the connector portion. [Brief explanation of the drawings]

[0020] [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. 2 is a plan view of the piezoelectric valve of FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 7 is a front view of the valve seat plate of FIG. 6. [Figure 8] FIG. 7 is a side view of the valve seat plate of FIG. 6. [Figure 9] FIG. 10 is a perspective view of the valve seat plate with the actuator fixed thereto. [Figure 10] FIG. 10 is a front view of the valve seat plate of FIG. [Figure 11] FIG. 10 is a side view of the valve seat plate of FIG. [Figure 12] FIG. 10 is a bottom view of the valve seat plate of FIG. [Figure 13] FIG. 2 is an explanatory diagram of the ejector as viewed from the front side. [Figure 14] FIG. 14 is a cross-sectional view of FIG. 13 FF. [Figure 15] FIG. [Figure 16] FIG. [Figure 17] FIG. [Figure 18] FIG. 1 is an exploded view of a piezoelectric valve. DETAILED DESCRIPTION OF THE INVENTION

[0021] 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 plan view of the piezoelectric valve of Figure 1. Figure 4 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.

[0022] The valve body 2 is a case with an open rear surface (bottom surface in FIG. 4), 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). Furthermore, a connector portion 5 is provided on the front surface (top surface in FIG. 4) 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, as shown in FIG.

[0023] An intake port 51 for drawing compressed gas into the valve body 2 and a plurality of exhaust ports 52 for discharging the compressed gas are opened on the front surface (top surface in FIG. 1) of the connector portion 5. In addition, a gas supply port 21 communicating with the intake port 51 of the connector portion 5, and a plurality of gas exhaust ports 22 communicating with each of the exhaust ports 52 of the connector portion 5 are opened on the front surface of the valve body 2.

[0024] As shown in Figures 1 and 2, a cover body 6 is attached to the rear surface of the valve body 2, and a cable (not shown) for supplying power to a piezoelectric element 32, which will be described later, extends from an opening formed on the front side of the cover body 6.

[0025] In the embodiments of the present invention, unless otherwise specified, the "width direction" refers to the width direction W of the piezoelectric valve when viewed from the front, as shown in, for example, FIGS.

[0026] FIG. 5 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The actuator 3 includes the support portion 33 and the action portion 34 as a displacement magnification 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 action 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.

[0031] 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.

[0032] 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 .

[0033] 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 .

[0034] 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.

[0035] 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.

[0036] Figure 6 shows a perspective view of the valve seat plate. Figure 7 shows a front view of the valve seat plate of Figure 6. Figure 8 shows a side view of the valve seat plate of Figure 6. 6 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 abuts, are provided on each of the opposing front and rear sides of the valve seat portion 41. Here, the valve seats 42 are provided in pairs on both surfaces of the valve seat portion 41 so as to face each other and overlap in the width direction when viewed from the front.

[0037] 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 side 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.

[0038] As shown in Figure 8, 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 6 to 8). 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.

[0039] Here, the discharge channels 45, one end of which opens into each of the valve seats 42 provided in pairs on both surfaces of the valve seat portion 41 so as to face each other, are formed in the valve seat plate 4 so as to overlap in the width direction. Therefore, as shown in FIG. 6, the other ends of the plurality of discharge paths 45 open at the front surface of the valve seat plate 4 in a non-aligned manner in the width direction (do not open in a line in the width direction). As shown in FIG. 4, the plurality of gas discharge ports 22 are opened in a non-linear fashion in the width direction on the front surface of the valve body 2 in which the valve seat plate 4 is housed.

[0040] In addition, each of the valve seats 42 of the valve seat plate 4 is provided in pairs on both sides of the valve seat 41 portion so as to overlap at least partially in the width direction when viewed from the front, and each of the discharge channels 45, one end of which opens into each of the valve seats 42 provided in pairs on both sides of the valve seat portion 41, may be formed on the valve seat plate 4 so as to overlap at least partially in the width direction.

[0041] Figure 9 shows a perspective view of the valve seat plate with the actuator fixed. Figure 10 shows a front view of the valve seat plate of Figure 9. Figure 11 shows a side view of the valve seat plate of Figure 9. Figure 12 shows a bottom view of the valve seat plate of Figure 9. 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.

[0042] 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. 9 to 11) 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 on 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 lower surface in Figures 9 to 11) and is connected to a cable (not shown) for supplying power to the piezoelectric element 32.

[0043] 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.

[0044] 13 and 14 are explanatory diagrams of an ejector in an optical sorting machine, with FIG. 13 being an explanatory diagram of the ejector seen from the front side, and FIG. 14 being an FF cross-sectional view of FIG. 13 and showing the ejector seen from the side. The ejector 7 shown in FIGS. 13 and 14 includes a manifold 71 having an air space 711 therein to which compressed air is supplied from a compressed air supply source (not shown), the piezoelectric valve 1 attached to the manifold 71 via the connector portion 5, and a nozzle member 72 attached to the manifold 71.

[0045] The manifold 71 has a number of air supply passages 712 and a number of exhaust passages 713 in the longitudinal direction that communicate with the air space 711, and each of the air supply passages 712 and each of the exhaust passages 713 open in a straight line in the longitudinal direction, and each of the multiple exhaust passages 713 is provided in communication with a nozzle hole 721 of the nozzle member 72.

[0046] The piezoelectric valve 1 is attached to the manifold 71, the intake port 51 of the connector portion 5 is connected to the air supply passage 712 of the manifold 71, and the multiple exhaust ports 52 of the connector portion 5 are connected to the multiple exhaust passages 713 of the manifold 71.

[0047] The manifold 71 is formed with one intake passage 712 and four exhaust passages 713 as a pair, and the pairs of intake passages 712 and exhaust passages 713 are formed along the longitudinal direction in the same number as the number of piezoelectric valves 1 attached to the manifold 71.

[0048] Figure 15 shows a left side view of the connector section, Figure 16 shows a plan view of the connector section, and Figure 17 shows a bottom view of the connector section. The connector portion 5 has an intake passage formed on its rear surface, one end of which is connected to the gas supply port 21 that opens to the front of the valve body 2, and the other end of which is connected to the air supply passage 712 formed in the manifold 71 on its front surface. In addition, the connector portion 5 is formed with a plurality of exhaust passages at its rear surface, one end of which is connected to each of the plurality of gas exhaust ports 22 that open to the front surface of the valve body 2, and the other end of which is connected to each of the plurality of exhaust passages 713 that open to the lower surface of the manifold 71 at its front surface.

[0049] The exhaust ports 52 (other end openings 521) of the multiple exhaust passages open in a row in the width direction on the front surface of the connector portion 5, and each of the exhaust passages communicates with each of the exhaust passages 713 that open in a straight line in the longitudinal direction on the underside of the manifold 71.

[0050] Furthermore, on the rear surface of the connector portion 5, the multiple exhaust passages open in an elongated hole shape (one end side opening 522) that connects the openings of the multiple gas exhaust ports 22 that open on the front surface of the valve body 2 and the multiple exhaust ports 52 that open on the front surface of the connector portion 5, and each of the exhaust passages is connected to the multiple gas exhaust ports 22 that open non-linearly in the width direction on the front surface of the valve body 2.

[0051] The plurality of discharge passages formed in the connector portion 5 each have a space with approximately the same spatial volume, and each have openings (discharge ports 52) on the front surface of the connector portion 5 with approximately the same opening area. Moreover, the plurality of gas discharge ports 22 opening on the front surface of the valve body 2 have approximately the same opening area.

[0052] Figure 18 shows an exploded view of the piezoelectric valve. The piezoelectric valve 1 can be assembled by inserting the valve seat plate 4, to which the four actuators 3 are 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 material 46 provided on the valve seat plate 4, fixing the cover body 6 to the rear surface of the lid material 46, and attaching the connector part 5 to the front surface of the valve body 2.

[0053] The valve seat plate 4 is fixed to the valve body 2 from the front with screws 81, 81 at the front part on the side having the respective discharge channels 45, where the front surface where the respective discharge channels 45 open within the case of the valve body 2, and the respective discharge channels 45 communicate with the respective gas discharge ports 22 that open on the front surface of the valve body 2.

[0054] In addition, the valve seat plate 4 has the cover member 46 fixed to the valve body 2 from the rear by screws 82, 82 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.

[0055] In this case, the portion where the front surface of the valve seat plate 4 is fixed to the front inner surface of the valve body 2 and where the discharge path 45 of the valve seat plate 4 communicates with the gas discharge port 22 of the valve body 2 is sealed with a packing 85, 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 86, thereby preventing gas leakage from the valve body 2.

[0056] The cover body 6 is fixed to the rear surface of the cover material 46 of the valve seat plate 4 with screws 84 or the like, and the cable 49 connected to the wiring pin 48 extending rearward from the rear surface of the cover material 46 and for supplying power to the piezoelectric element 32 extends from an opening on the front side.

[0057] The connector portion 5 is fixed to the front surface of the valve body 2 by screws 53, 53 from the front. At this time, the portion where each gas exhaust port 22 opening on the front surface of the valve body 2 communicates with the openings of the multiple exhaust passages (one end side openings 522) opening on the rear surface of the connector portion 5 is sealed with a gasket 25.

[0058] Furthermore, a gasket 55 is provided on the front surface of the connector portion 5 where the multiple exhaust ports 52 (other end openings 521) open, and seals the portion where each exhaust port 52 of the connector portion 5 communicates with each exhaust passage of the manifold 71 when the piezoelectric valve 1 is attached to the manifold 71.

[0059] In the piezoelectric valve 1, the valve seat plate 4 is fixed to the valve body 2 at the front part on the side having the discharge passage 45 and at the rear part on the side on which the actuator 3 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, with the piezoelectric valve, it is possible to 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 to prevent malfunction due to such contact.

[0060] Furthermore, in the piezoelectric valve 1, the valve seat plate 4 is fixed from the front to the valve body 2 with screws 81, 81 at the front part on the side having the discharge channel 45, where the front surface where the discharge channel 45 opens inside the case of the valve body 2, and the cover material 46 is fixed from the rear to the valve body 2 with screws 82, 82 at the rear part on the side where the actuator 3 is fixed. Therefore, the valve can be disassembled by removing the screws, and it is possible to investigate the cause of a malfunction and to carry out repairs.

[0061] Furthermore, as shown in FIG. 18, the valve seat plate 4 can be fixed at both side surfaces to the valve body 2 by screws 83, 83 from both sides at the rear portion on the side where the actuator 3 is fixed. If the valve seat plate 4 is fixed to the valve body 2 on both sides with screws 83, 83 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.

[0062] When electricity is applied to the piezoelectric element 32 of the actuator 3 in the piezoelectric valve 1 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 21 to the valve body 2 is discharged from the discharge path 45 formed in the valve seat portion 41 of the valve seat plate 4 through the gas discharge port 22 opening to the front surface of the valve body 2 and out the discharge port 52 opening to the front surface of the connector portion 5. 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.

[0063] In the piezoelectric valve 1 according to the embodiment of the present invention, the valve seats 42 of the valve seat plate 4 are provided in pairs on both sides of the valve seat portion 41 so as to overlap at least partially in the width direction in a front view, and each of the exhaust channels 45, one end of which opens into each of the valve seats 42 provided in pairs on both sides of the valve seat portion 41 so as to overlap at least partially in the width direction, is formed in the valve seat plate 4, and the other ends of the plurality of exhaust channels 45 open non-aligned in the width direction on the front surface of the valve seat plate 4, and the plurality of gas exhaust ports 22 open non-aligned in the width direction on the front surface of the valve body 2 in which the valve seat plate 4 is housed, while the exhaust ports 52 of the plurality of exhaust passages open in a line in the width direction on the front surface of the connector portion 5. Therefore, even if the plurality of gas exhaust ports 22 do not open in a line in the width direction on the front surface of the valve body 2, the gas exhaust ports can be opened in a line in the width direction on the front surface of the valve.

[0064] In the piezoelectric valve 1 according to the embodiment of the present invention, the multiple exhaust passages formed in the connector portion 5 each have a space of approximately the same spatial volume, and have openings (exhaust ports 52) with approximately the same opening area on the front surface of the connector portion 5. Since the multiple gas exhaust ports 22 opening on the front surface of the valve body 2 have approximately the same opening area, various characteristics such as the amount of gas ejected from the front surface of the valve, the ejection speed, and responsiveness can be made to be approximately the same among the multiple exhaust passages, and can be maintained in a good condition comparable to that when the connector portion 5 is not provided.

[0065] 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.

[0066] In the above embodiment of the present invention, the piezoelectric valve 1 has two actuators 3 fixed to each side of the valve seat plate 4, and four gas discharge ports 22 opening on the front surface of the valve body 2, but this is not limited to this. For example, two actuators 3 can be fixed to only one side of the valve seat plate 4, or one actuator can be fixed to each side of the valve seat plate 4, and two gas discharge ports 22 can be opened on the front surface of the valve body 2.

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

[0068] The piezoelectric valve of the present invention can reduce the widthwise dimension when viewed from the front compared to conventional valves, and even in cases where it is not possible to open multiple gas exhaust ports in a line in the widthwise direction on the front surface of the valve body, it is possible to open the gas exhaust ports in a line in the widthwise direction on the front surface of the valve, making it highly convenient. [Explanation of symbols]

[0069] 1 Piezoelectric valve 2 Valve body (body case) 21 Gas supply port 22 Gas outlet 25 Gasket 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 49 Cable 5 Connector part 51 Intake port 52 Outlet 521 Other end opening 522 One end opening 53 screws 55 Gasket 6 Cover body 7 Ejector 71 Manifold (fluid equipment) 711 Air Space 712 Air supply passage 713 Exhaust passage 72 Nozzle member 721 Nozzle hole 81 screws 82 screws 83 screws 84 screws 85 Gasket 86 O-ring

Claims

1. 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, Each of the plurality of actuators 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 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, the valve seat plate has a valve seat portion in which the valve seat and the discharge path are formed, the plurality of valve seats being provided on both the front side and the back side of the valve seat portion, the plurality of actuators are fixed to side surfaces of the valve seat plate so that the valve bodies face the respective valve seats, The main body case includes: a gas supply port through which compressed gas is supplied; a plurality of gas discharge ports that individually discharge the compressed gas supplied from the gas supply port through the plurality of discharge paths of the valve seat plate by separating the plurality of valve bodies from the plurality of valve seats, The piezoelectric valve is detachable from a fluid device via a connector provided on the front surface of the main body case, the connector portion has an intake passage, one end of which communicates with the gas supply port opening at the front surface of the main body case and the other end of which can communicate with an air supply passage formed in the fluid device, and a plurality of exhaust passages, one end of which communicates with each of the plurality of gas exhaust ports opening at the front surface of the main body case and the other end of which can communicate with each of a plurality of exhaust passages formed in the fluid device, the valve seats of the valve seat plate are provided in pairs on both surfaces of the valve seat portion so as to overlap at least partially in the width direction in a front view, the discharge passages, one end of which opens into the valve seats provided in pairs on both surfaces of the valve seat portion, are formed in the valve seat plate so as to overlap at least partially in the width direction; The other ends of the plurality of discharge channels are open on the front surface of the valve seat plate in a non-aligned manner in the width direction, The plurality of gas discharge ports are open on the front surface of the main body case in a non-linear manner in the width direction, A piezoelectric valve characterized in that the outlets of the plurality of exhaust passages are open in a row in the width direction on the front surface of the connector portion.

2. 2. The piezoelectric valve according to claim 1, wherein the plurality of discharge passages of the connector portion each have a space of the same volume and have openings of the same opening area on the front surface of the connector portion.

3. The piezoelectric valve according to claim 2 , wherein the plurality of gas discharge ports provided in the main body case have openings with the same opening area on the front surface of the main body case.

4. A piezoelectric valve as described in any one of claims 1 to 3, wherein the fluid device is a manifold, in which compressed gas supplied from a compressed gas source is supplied from the supply passage to the inside of the main body case through the intake passage of the connector portion, while compressed gas discharged from the inside of the main body case is exhausted from the multiple exhaust passages through the multiple exhaust passages of the connector portion.

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