JP6382658B2 - Piezoelectric valve - Google Patents

Description

The present invention relates to a piezoelectric valves that utilize the displacement of the multilayer piezoelectric element to open and close the valve.

  2. Description of the Related Art Conventionally, there is known a piezoelectric valve that opens and closes a valve using displacement of a multilayer piezoelectric element and ejects compressed gas (see Patent Document 1).

  The piezoelectric valve described in Patent Document 1 utilizes the characteristics of a multilayer piezoelectric element excellent in high-speed response performance, and has a displacement expansion mechanism that expands a small displacement of the multilayer piezoelectric element based on the lever principle. It is to be prepared.

When a voltage is applied to the multilayer piezoelectric element, the piezoelectric valve transmits a displacement in the extending direction of the multilayer piezoelectric element to the valve body via the displacement enlarging mechanism, and moves the valve body quickly. Open the valve.
Further, when the voltage application to the multilayer piezoelectric element is released, the piezoelectric valve transmits a return force accompanying the return of the original state of the multilayer piezoelectric element to the valve body via the displacement enlarging mechanism, and the valve body Is immediately brought into contact with the valve seat and closed.

By the way, the multilayer piezoelectric element has excellent features such as low energy consumption accompanying operation, suitable for high-speed operation, and small size.
However, since the laminated piezoelectric element has a piezoelectric ceramic layer, it is structurally fragile, and when using the piezoelectric valve, there is a possibility that broken pieces may be ejected together with the compressed gas.

  Further, since the multilayer piezoelectric element is vulnerable to a high humidity environment, when the piezoelectric valve is used in a high humidity environment, moisture penetrates into the multilayer piezoelectric element and the life of the piezoelectric valve is reduced. There is a problem of shortening.

  A resin-encased piezoelectric element in which the side surface of the laminated piezoelectric element is coated with an epoxy resin is commercially available. However, the resin-encased piezoelectric element does not sufficiently prevent scattering of broken pieces and has sufficient water resistance. It cannot be said.

  Increasing the thickness of the coating layer made of the epoxy resin can be expected to improve the scattering prevention effect and water resistance of the broken pieces in the resin-encased piezoelectric element. This increases the displacement of the piezoelectric element.

JP2013-124695A

Therefore, the present invention is a piezoelectric valve that opens and closes a valve by utilizing the displacement of a multilayer piezoelectric element, and there is no possibility that a broken piece of the multilayer piezoelectric element is ejected together with the compressed gas during use. An object of the present invention is to provide a piezoelectric valve in which moisture does not penetrate into the multilayer piezoelectric element even when used in an environment, and there is no risk of shortening its life .

In order to achieve the above object, the present invention provides:
A piezoelectric valve that opens and closes a valve using the displacement of a laminated piezoelectric element,
A valve body having a gas pressure chamber for receiving compressed gas supplied from the outside;
A valve body, a laminated piezoelectric element that generates a driving force necessary for the operation of the valve body as a displacement, a displacement enlarging mechanism that enlarges the displacement of the laminated piezoelectric element and acts on the valve body, An actuator disposed inside the piezoelectric valve,
The multilayer piezoelectric element has a surface covered with a polyolefin-based resin.

The piezoelectric valve of the present invention is
The laminated piezoelectric element is embedded in the polyolefin resin in a state of being integrated with the actuator .

The piezoelectric valve of the present invention is
The plate further includes a plate disposed inside the valve body, and the actuator is fixed to the plate, and is disposed inside the valve body together with the plate. It is preferable that the polyolefin resin is embedded in an actuator, and the actuator is fixed to the plate.

The piezoelectric valve of the present invention is
The laminated piezoelectric element is preferably integrated with the actuator, and the actuator is fixed to the plate and is embedded in the polyolefin-based resin in a state of being disposed inside the valve body together with the plate.

A laminated piezoelectric element suitable for use in the piezoelectric valve of the present invention is:
A laminated body in which piezoelectric ceramic layers and internal electrode layers are alternately laminated, and the laminated body includes external electrodes in which the internal electrode layers are exposed on opposite side surfaces and are electrically connected to the internal electrode layers;
The side surface from which the internal electrode layer is exposed is preferably covered with a polyolefin resin.
In addition, a laminated piezoelectric element suitable for use in the piezoelectric valve of the present invention is:
A laminated body in which piezoelectric ceramic layers and internal electrode layers are alternately laminated, wherein the laminated body has the internal electrode layers exposed on opposite side surfaces, and the exposed internal electrode layers are formed on each of the side surfaces; And an external electrode that covers the insulating layer and is electrically connected to the internal electrode layer that is not covered by the insulating layer.
The side surface from which the internal electrode layer is exposed is preferably covered with a polyolefin resin.

  The piezoelectric valve of the present invention is a polyolefin having a characteristic that the Young's modulus is small and excellent in flexibility as compared with a conventional epoxy resin, and the moisture permeability is small and the water resistance is excellent as compared with the epoxy resin. Since a laminated piezoelectric element covered with a resin is used, the laminated piezoelectric element is not spouted with a compressed gas when the piezoelectric valve is used, and the laminated piezoelectric element is used even in a high humidity environment. There is no risk of moisture entering the piezoelectric element and shortening its life.

Piezoelectric valve of the present invention, the laminated piezoelectric element, since it is embedded in the polyolefin resin in a state of being integrated in the actuator, it is assumed that the surface of the multilayer piezoelectric element is covered thicker the polyolefin resin Therefore, when the piezoelectric valve is used, a broken piece of the multilayer piezoelectric element is not ejected together with the compressed gas. Even when used in a high humidity environment, moisture penetrates into the multilayer piezoelectric element. There is no risk of shortening the service life.

  In the piezoelectric valve of the present invention, if the multilayer piezoelectric element is integrated with an actuator, and the actuator is fixed to a plate and embedded in a polyolefin-based resin, the surface of the multilayer piezoelectric element is Since it can be thickly covered with the polyolefin-based resin layer, when the piezoelectric valve is used, the broken piece of the laminated piezoelectric element is not ejected together with the compressed gas, and is used in a high humidity environment. However, there is no possibility that moisture will penetrate into the multilayer piezoelectric element and the lifetime will be shortened.

  In the piezoelectric valve according to the present invention, the laminated piezoelectric element is integrated with an actuator, and the actuator is fixed to a plate and embedded in the valve body together with the plate with a polyolefin resin. Then, since the surface of the multilayer piezoelectric element can be covered with the polyolefin resin layer thickly, a broken piece of the multilayer piezoelectric element is ejected together with the compressed gas when the piezoelectric valve is used. Even when used in a high-humidity environment, there is no possibility that moisture will penetrate into the multilayer piezoelectric element and the lifetime will be shortened.

The laminated piezoelectric element suitable for use in the piezoelectric valve of the present invention has a characteristic that the side surface where the internal electrode layer is exposed has a small Young's modulus and excellent flexibility as compared with a conventional epoxy resin, and Since it is covered with a polyolefin-based resin having small moisture permeability and excellent water resistance as compared with the epoxy resin, it is possible to prevent scattering of broken pieces without hindering displacement, and excellent water resistance.

Sectional drawing of a laminated piezoelectric element. The perspective view of a piezoelectric valve. The assembly exploded view of a piezoelectric valve. Explanatory drawing of an actuator. Explanatory drawing of the state which fixed the actuator to the valve seat plate. It is sectional drawing of a piezoelectric valve, Comprising: Explanatory drawing of the state which has arrange | positioned the valve seat plate inside the valve main body.

Embodiments of the present invention will be described with reference to the drawings.
<Laminated piezoelectric element>
FIG. 1 is a cross-sectional view of a typical example of a multilayer piezoelectric element.
In the embodiment of the present invention, the multilayer piezoelectric element 1 has a laminate 4 in which piezoelectric ceramic layers 2 and internal electrode layers 3 are alternately laminated. The laminated body 4 has the internal electrode layer 3 exposed on the opposite side surfaces, and the exposed internal electrode layers 3 are covered with an insulating layer 5 every other side surface, and the insulating layer 5 is further covered. An external electrode 6 is provided which is electrically connected to the internal electrode layer 3 which is covered and not covered by the insulating layer 5.
The laminated piezoelectric element 1 has a side surface from which the internal electrode layer 3 is exposed covered with a polyolefin resin 8 such as polyethylene or polypropylene.

  Here, it is sufficient that the multilayer piezoelectric element 1 has at least a side surface where the internal electrode layer 3 is exposed to be covered with the polyolefin resin 8, and preferably includes all the side surfaces where the internal electrode layer 3 is exposed. As long as the surface is covered with the polyolefin-based resin 8.

The polyolefin-based resin 8 has a characteristic that it has a small Young's modulus and excellent flexibility as compared with an epoxy resin that covers the side surface where the internal electrode layer is exposed in a conventional multilayer piezoelectric element.
Therefore, in the embodiment of the present invention, the multilayer piezoelectric element 1 has at least the side surface from which the internal electrode layer 3 is exposed, preferably the entire surface including the side surface from which the internal electrode layer 3 is exposed. Even when the resin is thickly covered with the resin 8, it is possible to prevent the broken pieces from being scattered without hindering the displacement.

In addition, the polyolefin resin 8 has a property of having a small moisture permeability and excellent water resistance as compared with the epoxy resin.
Therefore, in the embodiment of the present invention, the multilayer piezoelectric element 1 has at least the side surface where the internal electrode layer 3 is exposed, preferably all the surfaces including the side surface where the internal electrode layer 3 is exposed are polyolefin-based. Since it is covered with the resin 8, it is excellent in water resistance.

  In the embodiment of the present invention, the multilayer piezoelectric element has been described as a representative example of the type shown in FIG. 1, but at least the side surface where the internal electrode layer is exposed, preferably the internal electrode layer is exposed. As long as all the surfaces including the side surfaces to be covered are covered with a polyolefin resin such as polyethylene or polypropylene, other types of laminated piezoelectric elements may be used.

<Piezoelectric valve>
FIG. 2 shows a perspective view of the piezoelectric valve. FIG. 3 shows an exploded view of the piezoelectric valve. FIG. 4 is an explanatory diagram of the actuator. FIG. 5 is an explanatory view showing a state in which the actuator is fixed to the valve seat plate. FIG. 6 is a cross-sectional view of a piezoelectric valve, and shows an explanatory view of a state in which a valve seat plate is disposed inside the valve body.

  In the embodiment of the present invention, the piezoelectric valve 10 includes a valve body 20, a valve seat plate 25 that is disposed inside the valve body 20 and is fixed to the valve body 20, and both surfaces of the valve seat plate 25. And an actuator 30 fixed with screws.

The valve body 20 is a case having an open front surface, and includes a gas pressure chamber that receives compressed gas supplied from an external compressed gas supply source (not shown).
A connector 50 is provided on the front surface of the valve body 20. A gas suction port 51 for sucking compressed gas and a gas discharge port 52 for discharging the compressed gas are opened in the front surface of the connector part 50.

  The valve seat plate 25 has a valve seat 26 on which both sides of the actuator 30 are attached and a valve body 31 (to be described later) of the actuator 30 abuts. A lid member 28 for closing the opening of the case is attached to the front surface of the valve seat plate 25. The lid member 28 is formed with a gas discharge path that communicates from the valve seat surface of the valve seat 26 to the discharge port 52 that opens to the front surface of the connector portion 50. Further, the lid member 28 is formed with a gas suction path that communicates with the inside of the valve body 20 from a suction port 51 that opens to the front surface of the connector portion 50.

  As shown in FIG. 4, the actuator 30 is made of rubber, preferably slippery rubber valve body 31, laminated piezoelectric element 32 that generates a driving force required for the operation of valve body 31 as a displacement, and laminated piezoelectric element. A displacement magnifying mechanism 33 is provided for enlarging the displacement of the element 32 to act on the valve body 31.

  The displacement magnifying mechanism 33 includes a displacement magnifying unit 34 that magnifies the displacement of the multilayer piezoelectric element 32 and a displacement transmission unit 35 that transmits the displacement of the multilayer piezoelectric element 32 to the displacement magnifying unit 34. The valve body 31 is arranged symmetrically with respect to an axis of the operation direction, here, a straight line connecting the valve body 31 and the longitudinal axis of the multilayer piezoelectric element 32 (hereinafter referred to as “center line”).

  The displacement transmission unit 35 includes a U-shaped base substrate 36 to which one end of the multilayer piezoelectric element 32 is bonded, and a cap member 37 to which the other end of the multilayer piezoelectric element 32 is bonded. By disposing the multilayer piezoelectric element 32 in the space of the U-shaped base substrate 36, the displacement enlarging mechanism 33 is arranged symmetrically about the longitudinal axis of the multilayer piezoelectric element 32. The

  Here, the laminated piezoelectric element 32 is incorporated in the space of the U-shaped base substrate 36 and between the U-shaped bottom portion of the base substrate 36 and the cap member 37, and the base substrate 36. By plastically deforming the U-shaped bottom portion, the one end is joined to the U-shaped bottom portion of the base substrate 36 and the other end is joined to the cap member 37.

The displacement magnifying part 34 includes first and second displacement magnifying parts 34a and 34b that are symmetrically arranged with respect to the center line.
The first displacement enlarged portion 34 a includes first and second hinges 39 and 40, a first arm 41, and a first leaf spring 42. One end of the first hinge 39 is integrated with one end of the U-shaped base substrate 36, and one end of the second hinge 40 is integrated with the cap member 37. One end of the first leaf spring 42 is joined to the outer front end portion of the first arm 41, and one side end portion of the valve body 31 is joined to the other end of the first leaf spring 42. .

On the other hand, the second displacement enlarged portion 34 b includes third and fourth hinges 43 and 44, a second arm 45, and a second leaf spring 46. One end of the third hinge 43 is integrated with the other end of the U-shaped base substrate 36, and one end of the fourth hinge 44 is integrated with the cap member 37. One end of the second leaf spring 46 is joined to the outer front end portion of the second arm 45, and the other side end portion of the valve body 31 is joined to the other end of the second leaf spring 46. .
Here, the displacement magnifying mechanism 33 can be integrally formed by punching a metal material such as stainless steel.

  When the actuator 30 is energized to the multilayer piezoelectric element 32 in a valve-closed state, the multilayer piezoelectric element 32 expands. In the displacement magnifying mechanism 33, the displacement accompanying the extension of the multilayer piezoelectric element 32 is such that the first and third hinges 39 and 43 are fulcrums, the second and fourth hinges 40 and 44 are force points, The outside tips of the second arms 41 and 45 are enlarged by the lever principle with the point of action as the action point, and the outside tips of the first and second arms 41 and 45 are greatly displaced.

  Then, the displacement of the outer front ends of the first and second arms 41, 45 causes the valve body 31 to be separated from the valve seat 26 via the first and second leaf springs 42, 46, and the gas discharge. Open the road.

  On the other hand, when the actuator 30 is deenergized, the multilayer piezoelectric element 32 contracts, and the contraction causes the valve element 31 to move through the displacement enlarging mechanism 33. 26, and the gas discharge path is closed.

  In the embodiment of the present invention, the laminated piezoelectric element 32 of the piezoelectric valve 10 has at least a side surface from which the internal electrode layer is exposed, preferably all surfaces including the side surface from which the internal electrode layer is exposed. A laminated piezoelectric element covered with a polyolefin resin such as polypropylene or the like (for example, a laminated piezoelectric element 1 of the type shown in FIG. 1) can be used.

Even when the laminated piezoelectric element 32 is formed such that at least the side surface where the internal electrode layer is exposed, preferably all the surfaces including the side surface where the internal electrode layer is exposed, is thickly covered with the polyolefin-based resin. It is possible to prevent the broken pieces from scattering without hindering the displacement.
Therefore, in the piezoelectric valve 10, as the multilayer piezoelectric element 32, at least the side surface on which the internal electrode layer is exposed, preferably all surfaces including the side surface on which the internal electrode layer is exposed, are polyolefins such as polyethylene and polypropylene. If a laminated piezoelectric element covered with a resin is used, a broken piece of the laminated piezoelectric element 32 is not ejected from the discharge port 52 together with the compressed gas when used.

In the case where the laminated piezoelectric element 32 has at least the side surface where the internal electrode layer is exposed, preferably the entire surface including the side surface where the internal electrode layer is exposed, covered with a polyolefin resin. Excellent water resistance.
Therefore, in the piezoelectric valve 10, as the multilayer piezoelectric element 32, at least the side surface on which the internal electrode layer is exposed, preferably all surfaces including the side surface on which the internal electrode layer is exposed, are polyolefins such as polyethylene and polypropylene. If a laminated piezoelectric element covered with a resin is used, even when the piezoelectric valve 10 is used in a high humidity environment, moisture penetrates into the laminated piezoelectric element 32 and its life is shortened. There is no risk of becoming.

Here, FIGS. 4 to 6 show examples in which the laminated piezoelectric element 32 is embedded in the polyolefin resin 80.
As shown in FIG. 4, in the embodiment of the present invention, the stacked piezoelectric element 32 is integrated with the actuator 30 with one end joined to the base substrate 36 and the other end joined to the cap member 37. Thus, it can be embedded in the polyolefin-based resin 80.

  The multilayer piezoelectric element 32 may be embedded in the polyolefin-based resin 80 together with the displacement transmission unit 35 side except the displacement expansion unit 34 of the displacement expansion mechanism 33 in the actuator 30. 4 is embedded in the polyolefin resin 80 together with the U-shaped bottom portion of the base substrate 36 to which one end is joined and the cap member 37 to which the other end is joined.

  As shown in FIG. 5, in the embodiment of the present invention, the piezoelectric valve 10 includes a laminated piezoelectric element 32 integrated with the actuator 30, and the actuator 30 is fixed to the valve seat plate 25. Thus, the laminated piezoelectric element 32 can be embedded in the polyolefin resin 80.

The laminated piezoelectric element 32, by pouring the polyolefin resin melted state on the valve seat plate 25, it is sufficient and it is embedded in the polyolefin resin 100, for example, as shown in FIG. 5 The actuator 30 may be embedded in the polyolefin-based resin 80 together with the displacement transmission unit 35 side excluding the displacement expansion unit 34 of the displacement expansion mechanism 33. Further, as shown in FIG. 4, the multilayer piezoelectric element 32 is embedded in the polyolefin resin 80 together with the U-shaped bottom portion of the base substrate 36 to which one end is joined and the cap member 37 to which the other end is joined. It can also be done.

  Further, as shown in FIG. 6, in the embodiment of the present invention, the piezoelectric valve 10 integrates the laminated piezoelectric element 32 into the actuator 30, and fixes the actuator 30 to the valve seat plate 25. The laminated piezoelectric element 32 may be embedded in the polyolefin resin 80 in a state where the valve seat plate 25 is disposed inside the valve body 20.

  The multilayer piezoelectric element 32 may be embedded in the polyolefin resin 80 by pouring the polyolefin resin in a melted state into the valve body 20, for example, as shown in FIG. The actuator 30 may be embedded in the polyolefin-based resin 80 together with the displacement transmitting portion 35 side except for the displacement enlarging portion 34 of the displacement enlarging mechanism 33. Further, as shown in FIG. 4, the multilayer piezoelectric element 32 is embedded in the polyolefin resin 80 together with the U-shaped bottom portion of the base substrate 36 to which one end is joined and the cap member 37 to which the other end is joined. It can also be done.

  In each of the examples shown in FIGS. 4 to 6, the multilayer piezoelectric element 32 includes the polyolefin-based resin 80 together with the displacement transmission portion 35 side except the displacement enlargement portion 34 of the displacement enlargement mechanism 33 in the actuator 30. As shown in FIG. 4, it is preferably embedded in the polyolefin resin 80 together with the U-shaped bottom portion of the base substrate 36 to which one end is joined and the cap member 37 to which the other end is joined. Therefore, the actuator 30 is not likely to be hindered by the polyolefin resin 80.

  Also, in each of the examples shown in FIGS. 4 to 6, the piezoelectric valve 10 can be formed such that the surface of the multilayer piezoelectric element 32 is thickly covered with the polyolefin-based resin 80. There is no possibility that broken pieces of the laminated piezoelectric element 32 are ejected from the discharge port 41 together with the compressed gas, and even when used in a high humidity environment, moisture penetrates into the laminated piezoelectric element 32 and its life is shortened. There is no risk of becoming.

  In each of the examples shown in FIGS. 4 to 6, the laminated piezoelectric element 32 includes a laminated piezoelectric element (for example, the type shown in FIG. 1) in which at least the side surface where the internal electrode layer is exposed is covered with a polyolefin-based resin. In addition to the multilayer piezoelectric element 1), various types of multilayer piezoelectric elements having side surfaces from which the internal electrode layers are exposed can be used.

  When the laminated piezoelectric element 32 is a laminated piezoelectric element in which at least the side surface where the internal electrode layer is exposed is covered with a polyolefin resin, the laminated piezoelectric element 32 is integrated with the actuator. At this time, the polyolefin-based resin may drop off from the surface of the multilayer piezoelectric element 32 at each joint portion on the base substrate 36 side and the cap member 37 side, but the examples shown in FIGS. Then, since the multilayer piezoelectric element 32 is integrated with the actuator and then embedded in the polyolefin resin 80, the piezoelectric valve 10 is a multilayer piezoelectric element whose surface is covered with the polyolefin resin 80 thickly. 32 may be provided.

  The present invention is not limited to the above-described embodiment, and it goes without saying that the configuration can be appropriately changed without departing from the scope of the invention.

  The present invention is a piezoelectric valve that opens and closes a valve by using displacement of a multilayer piezoelectric element, and in use, a broken piece of the multilayer piezoelectric element is not ejected together with a compressed gas, so that it can be used in a high humidity environment. Even when used in the above, there is no possibility of moisture entering the multilayer piezoelectric element and shortening its life, so that it can be used in various applications and various situations.

DESCRIPTION OF SYMBOLS 1 Laminated piezoelectric element 2 Ceramic layer 3 Internal electrode layer 4 Laminated body 5 Insulating layer 6 External electrode 7 Lead wire 8 Polyolefin resin 10 Piezoelectric valve 20 Valve body 25 Valve seat plate 26 Valve seat 28 Lid material 30 Actuator 31 Valve body 32 Laminated piezoelectric element 33 Displacement enlarging mechanism 34 Displacement enlarging unit 35 Displacement transmitting unit 36 Base substrate 37 Cap unit 39 First hinge 40 Second hinge 41 First arm 42 First leaf spring 43 Third hinge 44 Fourth hinge 45 First 2 arms 46 2nd leaf spring 50 connector 51 gas inlet 52 gas outlet 80 polyolefin resin

Claims (3)

A piezoelectric valve that opens and closes a valve using the displacement of a laminated piezoelectric element,
A valve body having a gas pressure chamber for receiving compressed gas supplied from the outside;
A valve body, a laminated piezoelectric element that generates a driving force necessary for the operation of the valve body as a displacement, a displacement enlarging mechanism that enlarges the displacement of the laminated piezoelectric element and acts on the valve body, An actuator disposed inside the piezoelectric valve,
The multilayer piezoelectric element is covered with the surface of a polyolefin-based resin, piezoelectric valve, wherein Rukoto embedded in the polyolefin resin in the integrated state in the actuator. A plate disposed inside the valve body, and the actuator is fixed to the plate and is disposed inside the valve body together with the plate;
The multilayer piezoelectric element, the integrated actuator, piezoelectric valve according to claim 1 wherein said actuator is embedded in the polyolefin resin in a state of being fixed to said plate. 3. The piezoelectric valve according to claim 2, wherein the laminated piezoelectric element is embedded in the polyolefin resin in a state where the actuator is fixed to the plate and is disposed inside the valve body together with the plate.

Images