JP2023126991A - Pump and fluid control device - Google Patents

Abstract

To provide a pump having a structure in which suction capacity is hardly decreased even if it is downsized, and a fluid control device.SOLUTION: A pump comprises an actuator element 30 comprising a first principal surface 32a and a second principal surface 32b opposed to each other, a first plate 40 comprising an opposed part including a first surface 41a opposed to the second principal surface 32b of the actuator element 30 via a space E1, a housing 20 internally housing the actuator element 30 and the opposed part of the first plate 40, and a protrusion part 26 protruding from the housing 20 toward the inside of the housing 20. The protrusion part 26 is connected to the actuator element 30 at a position closer to a center of the actuator element 30 than a node part N generated when the actuator element 30 vibrates at a natural frequency.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD This disclosure relates to pumps and fluid control devices.

2. Description of the Related Art As a small pump for transporting fluid such as gas or liquid, a pump is known that includes a housing having a fluid inlet and a fluid outlet, and an actuator element disposed inside the housing. Further, a fluid control device that combines this small pump and a container that can temporarily store fluid sent from the small pump is used, for example, as a blood pressure monitor (see, for example, Patent Document 1).

In the above-mentioned small pump, due to the bending movement of the actuator element, the fluid introduced into the housing from the fluid inlet flows along the surface of the actuator element and is discharged to the outside from the fluid outlet.

International Publication No. 2016/063710

In the technique disclosed in Patent Document 1, the diaphragm has a structure in which the diaphragm is elastically supported at two points on the frame plate by two connecting portions. That is, the peripheral portion of the piezoelectric actuator is not substantially restrained. As a result, the gap between the piezoelectric actuator and the fixed part cannot be accurately controlled, and pump performance may deteriorate in some cases.

The technology according to the present disclosure was made in consideration of such circumstances, and aims to provide a pump and a fluid control device that achieve high pump performance.

In one aspect of the present disclosure, the pump includes an actuator element having a first main surface and a second main surface facing each other, and a first surface facing the second main surface of the actuator element with a space therebetween. a first plate having a facing portion; a housing that accommodates the actuator element and the facing portion of the first plate; and a protrusion projecting inward from the housing, the protrusion It is connected to the actuator element at a position closer to the center of the actuator element than a node portion that occurs when the element vibrates at its natural frequency.

According to the technology according to the present disclosure, it is possible to provide a pump and a fluid control device that achieve high pump performance.

FIG. 1 is a sectional view showing a fluid control device including a pump according to a first embodiment of the present disclosure. 2 is a sectional view taken along line II-II in FIG. 1. FIG. 3 is a sectional view taken along line III-III in FIG. 2. FIG. 3 is a sectional view taken along the line IV-IV in FIG. 2. FIG. 3 is a sectional view taken along the line VV in FIG. 2. FIG. 2 is an explanatory diagram illustrating the operating state of the actuator element shown in FIG. 1. FIG. FIG. 2 is a sectional view showing a fluid control device including a pump according to a second embodiment of the present disclosure. FIG. 7 is a sectional view showing a fluid control device including a pump according to a third embodiment of the present disclosure. FIG. 9 is a partial cross-sectional view of FIG. 8;

DESCRIPTION OF THE PREFERRED EMBODIMENTS A pump and a fluid control device equipped with the same, which are embodiments to which the present disclosure is applied, will be described below with reference to the drawings. Note that the embodiments shown below are specifically described in order to better understand the gist of the invention, and do not limit the present disclosure unless otherwise specified. In addition, the drawings used in the following explanation may show important parts enlarged for convenience in order to make it easier to understand the features of the present disclosure, and the dimensional ratio of each component may be the same as the actual one. Not necessarily.

(First embodiment)
FIG. 1 is a perspective view of a fluid control device according to a first embodiment. FIG. 2 is a sectional view taken along the line II--II in FIG. 3 is a sectional view taken along line III-III in FIG. 2, FIG. 4 is a sectional view taken along line IV-IV in FIG. 2, and FIG. 5 is a sectional view taken along line V-V in FIG. FIG. 6 is an explanatory diagram illustrating the positional relationship between the node portion of the actuator element shown in FIG. 1 and the protrusion portion formed on the third housing member.

A fluid control device 1A according to the first embodiment includes a pump 11A and a container (tank) 2 that temporarily stores fluid sent from the pump 11A.
The pump 11A includes a housing 20, an actuator element 30, a flow path plate (first plate) 40, and a support member 50 that supports the actuator element 30.

The housing 20 is an exterior body of the pump 11A, and contains the actuator element 30 and the flow path plate 40 therein.
The housing 20 includes a first housing member 20A having a rectangular cylindrical shape and having a rectangular outer cross section and a rectangular inner cross section and extending along the thickness direction t.

Further, the housing 20 includes a second housing member 20B that is formed to close one open end of the first housing member 20A and is a bottomed cylindrical body having a rectangular outer cross section and a rectangular inner cross section. The second housing member 20B is connected to the first housing member 20A. Further, the housing 20 is formed so as to partially close the other open end of the first housing member 20A, and is a third housing member (position regulating member) has 20C. The third housing member (position regulating member) 20C is connected to the first housing member 20A.

The first housing member 20A, the second housing member 20B, and the third housing member (position regulating member) 20C that constitute the housing 20 may be integrally formed, for example.
Note that the housing 20 is not limited to the shape described above, and can be formed into any cylindrical shape.

A first opening portion (first opening) 21 is formed in the third housing member (position regulating member) 20C that constitutes the housing 20. Further, the second housing member 20B constituting the housing 20 is formed with a second opening portion (second opening) 22 that passes through the inner surface 20B1 facing the flow path plate 40 and the opposite surface 20B2. There is. When storing fluid in the container 2, the first opening 21 serves as a fluid inlet, and the second opening 22 serves as a fluid outlet. Moreover, when the fluid stored in the container 2 is discharged to the outside, the first opening 21 becomes a fluid discharge port, and the second opening 22 becomes a fluid introduction port.

A channel plate 40 is arranged between the second housing member 20B and the first housing member 20A of the housing 20. Thereby, the channel plate 40 is fixed to the housing 20. Further, a support member 50 is arranged between the first housing member 20A and the third housing member 20C. That is, the support member 50 is held between the first housing member 20A and the third housing member 20C. As a result, the support member 50 is supported inside the first housing member 20A and fixed to the housing 20.

In the present embodiment, in the housing 20, the second housing member 20B is connected to the first housing member 20A via the channel plate 40, and the third housing member 20C is connected to the first housing member 20A via the support member 50. is connected to.

Note that the method for fixing the channel plate 40 to the housing 20 is not limited to this. For example, the channel plate 40 may be fixed to the inner wall of the first housing member 20A of the housing 20 using an adhesive or the like.

The housing 20 has a rectangular outer cross section and an inner cross section. However, the shape of the housing 20 is not limited to this. For example, the housing 20 may have a square outer cross section and a circular inner cross section, a circular outer cross section and a circular inner cross section, or a circular outer cross section and a square inner cross section. You can leave it there. As a constituent material of the housing 20, for example, an insulating material such as resin or ceramics can be used.

It is preferable that the actuator element 30 vibrates (bending motion) at a predetermined frequency. Preferably, the actuator element 30 has a resonant frequency (natural frequency). The resonant frequency (natural frequency) of the actuator element 30 is, for example, in a range of 20 kHz or more.

In this embodiment, the actuator element 30 has a through hole 31 formed therein. The through hole 31 communicates with the first opening 21 of the housing 20. In this embodiment, the actuator element 30 is disc-shaped, and the through hole 31 is arranged at the center of the disc-shaped actuator element 30. Note that the shape of the actuator element 30 is not limited to a disk shape. The actuator element 30 may have a rectangular plate shape or a polygonal plate shape, for example. However, the shape of the actuator element 30 is preferably a disk shape from the viewpoint of suppressing the appearance of unnecessary resonance frequencies.

The actuator element 30 of this embodiment is composed of a vibration element 36. The vibrating element 36 is a piezoelectric vibrator that includes a piezoelectric plate 37 and electrodes 38a and 38b arranged on the upper and lower surfaces of the piezoelectric plate 37. The plate-shaped piezoelectric body 37 is made up of, for example, two piezoelectric bodies whose polarization directions are opposite to each other joined together. As a constituent material of the plate-shaped piezoelectric body 37, for example, a PZT-based piezoelectric vibrating material using lead zirconate titanate-based ceramics can be used. The plate-shaped piezoelectric body 37 in this embodiment is a combination of two bulk-type PZT-based piezoelectric vibrating materials whose polarization directions are opposite to each other.
Note that an electrostrictive vibrator may be used as the vibrating element 36 instead of a piezoelectric vibrator.

Actuator element 30 is joined to support member 50 by joint 53 .
The lower surface of the actuator element 30 is in contact with the protrusion (position regulating part) 26 via the support member 50. That is, the support member 50 contacts the protrusion (position regulating portion) 26 on the opposite surface (lower surface) to the surface (upper surface) on which the joint portion 53 is formed. Further, the through hole 31 of the actuator element 30 is arranged at a position communicating with the first opening 21 of the third housing member 20C.

The protruding part (position regulating part) 26 is arranged around the first opening part (first opening) 21 of the third housing member (position regulating member) 20C, and is arranged around the first opening part (first opening) 21 of the third housing member (position regulating member) 20C. , protrudes toward the inside of the housing 20. This protrusion (position regulating member) 26 is connected to a third housing member (position regulating member) 20C. In the present embodiment, the protrusion (position regulating part) 26 is integrally formed with the third housing member (position regulating member) 20C, as a structure included in the third housing member (position regulating member) 20C. Note that the protruding portion (position regulating portion) 26 may be configured as a separate member from the third housing member (position regulating member) 20C.

The protrusion (position regulating part) 26 is formed inside the node N that occurs when the actuator element 30 is vibrated, that is, closer to the center of the actuator element 30 . That is, the protrusion (position regulating part) 26 is connected to the actuator element 30 at a position closer to the center of the actuator element 30 than the node N that occurs when the actuator element 30 vibrates at its natural frequency. More specifically, the protrusion (position regulating part) 26 is connected to the actuator element 30 via the support member 50, and the support member 50 is connected to the actuator element 30 at a position closer to the center of the actuator element 30 than the node N. The surface to be joined to the actuator element 30 is in contact with the opposite surface.

Note that although the protrusion (position regulating portion) 26 is in contact with the surface of the support member 50 closer to the center of the actuator element 30 than the node N, which is opposite to the surface to be joined to the actuator element 30, The node N and the peripheral edge portion of the node N are not in contact with the surface of the support member 50 opposite to the surface to be joined to the actuator element 30 . That is, the protrusion (position regulating part) 26 is spaced apart from the support member 50 at the node N and closer to the periphery than the node N.

In the actuator element 30 of this embodiment, when a voltage is applied to the electrodes 38a and 38b via the wirings 51a and 51b, the vibration element 36 vibrates. The vibration of the vibration element 36 causes the actuator element 30 to vibrate (bending motion) at a predetermined frequency.

As shown in FIG. 6(a), when the vibrating element 36 is vibrated with nothing in contact with the vibrating element 36, there is no vibration at all within the plane of the vibrating element 36, and the amplitude is 0 at a node (node) N. Then, an antinode AN occurs where the amplitude is maximum and the displacement is the most oscillating. In this embodiment, when the vibration element 36 vibrates, the anti-node AN occurs at the center of the vibration element 36, and the node (node) N occurs inside the periphery of the vibration element 36.

As an example, when a vibrating element 36 including a vibrating element with a diameter D of 12 mm formed by forming a 10 μm thick PZT (lead zirconate titanate) film on a 260 μm thick Si single crystal film is vibrated (vibration resonance (gain 40 dB), the amplitude V1 of the anti-node AN is approximately 15 μm, and the amplitude V2 of the peripheral portion is approximately 11 μm.

As shown in FIG. 6(b), in this embodiment, at a circular position where the amplitude V1 of the antinode AN and the amplitude V2 of the peripheral edge when the vibration element 36 vibrates are the same, The protrusions (position regulating parts) 26 are provided so as to overlap. In this position, when e is the diameter of the cross-sectional center of the protrusion (position regulating part) 26 and c is the diameter of the node N, the relationship is such that c>e, that is, the protrusion (position regulating part) 26 is at the node It will be inside N. That is, the protrusion (position regulating part) 26 contacts the actuator element 30 inside the node N via the support member 50.

In the present embodiment, the actuator element 30 is in contact with the protrusion (position regulation part) 26 via the support member 50, and is pressed against the protrusion (position regulation part) 26 by the elastic force of the support member 50. They are configured so that they are not separated from each other.

The joint portion 53 where the actuator element 30 is joined to the support member 50 is formed closer to the center of the actuator element 30 than the node N mentioned above. That is, the actuator element 30 is supported by the support member 50 inside the node N (see FIGS. 2 and 5).

The support member 50 is formed of a flexible resin sheet so as not to hinder the vibration (bending motion) of the actuator element 30. Further, the flexible resin sheet may have insulation properties. An example of the flexible resin sheet having insulation properties is a polyimide sheet.

The support member 50 is bent in a crank shape toward the third housing member (position regulating member) 20C on the peripheral edge side of the joint portion 53. As a result, at the position of the node N of the actuator element 30, the supporting member 50 has a spaced apart portion 50a spaced apart from the actuator element 30 in the thickness direction t.

Further, the support member 50 is further bent into a crank shape on the peripheral edge side than the separation portion 50a, and a pull-out portion 50b extending to the outside of the housing 20 is formed from between the first housing member 20A and the third housing member 20C. ing.

The pull-out portion 50b of the support member 50 is formed at the same position in the thickness direction t with respect to the joint portion 53 of the support member 50. That is, the upper surface of the pull-out portion 50b of the support member 50 and the upper surface of the joint portion 53 of the support member 50 are on the same plane in the surface spreading direction f perpendicular to the thickness direction t. In this way, by forming the support member 50 into a bellows structure, the vibration of the actuator element 30 is not hindered, the amount of displacement is increased, and the pump performance can be improved.

Further, the support member 50 is disposed so as to cover the entire area between the actuator element 30 and the first housing member 20A when the support member 50 is viewed from the flow path plate 40 in plan. As a result, fluid flows from the first opening 21 only through the through hole 31. The other paths are blocked by the support member 50. Therefore, the support member 50 not only supports the actuator element 30 but also plays a role of blocking the fluid inflow path, so that the structure can be simplified.

As shown in FIG. 5, a power supply wiring 51 for supplying power to the actuator element 30 is formed in the support member 50. The power supply wiring 51 includes wirings 51a and 51b. The wiring 51a and the wiring 51b extend in mutually opposite directions along the surface spreading direction f. Therefore, the support member 50 not only supports the actuator element 30 but also plays the role of electrical wiring, making it possible to simplify the structure and reduce costs.

Wiring lines 51a and 51b connect electrodes 38a and 38b of vibration element 36 and a power source (not shown). The wiring 51a and the electrode 38a are connected through a through hole 52 formed in the plate-shaped piezoelectric body 37. The electrode 38b is formed so as to avoid the area around the through hole 52 so that the wiring 51a and the electrode 38b do not come into contact with each other. The wiring 51b is connected to the electrode 38b. The electrical connection T1 between the wiring 51a and the electrode 38a and the electrical connection T2 between the wiring 51b and the electrode 38b are each formed at a position inside the node N.

Hereinafter, in this embodiment, the surface of the actuator element 30 on the side connected to the protrusion (position regulating part) 26 via the support member 50 is the first main surface 32a, and the surface on the opposite side is the second main surface. 32b.
In this embodiment, the first main surface 32a of the actuator element 30 is one surface of the plate-shaped piezoelectric body 37, and the second main surface 32b is the other surface of the plate-shaped piezoelectric body 37.

The flow path plate 40 is arranged at a position facing the second main surface 32b of the actuator element 30 with a space E1 in between. The space E1 constitutes a part of the flow path of the fluid introduced into the interior of the housing 20, and the surface of the flow path plate 40 facing the space E1 is a first flow path surface 41a. The flow path plate 40 has a facing portion including a first flow path surface 41a facing the second main surface 32b of the actuator element 30. Note that the inner surface of the second housing member 20B extends so as to face a second flow path surface 41b (second surface) that is an opposite surface to the first flow path surface 41a of the flow path plate 40.

In this embodiment, a recess 42 is formed in the first flow path surface 41a of the flow path plate 40. The recess 42 is, for example, formed in an annular shape centered on the through hole 31 of the actuator element 30. This recess 42 forms in the space E1 an expanded portion E2 whose cross-sectional area along the thickness direction t is expanded. As a result, even if the size of the actuator element 30 of the pump 11A is reduced, Helmholtz resonance is likely to occur at low frequencies of 20 kHz or higher. Therefore, even when the size of the pump 11A is reduced, it is possible to increase the suction capacity of the pump 11A. The recess 42 may have a curved surface having an arc-shaped cross section. In this case, the fluid tends to flow more smoothly to the expanded portion E2.

The outer region of the flow path plate 40 that does not face the actuator element 30 is a connecting portion 40a, and a through hole 43 is formed in this connecting portion 40a. In this embodiment, the through-hole 43 has a rectangular shape when the flow path plate 40 is viewed from above, and the peripheral edge on the center side of the pump 11A overlaps with the peripheral edge of the actuator element 30, and the outer peripheral edge of the pump 11A overlaps with the peripheral edge of the actuator element 30. It is located at a distance from the first housing member 20A. That is, the connecting portion 40a is connected to the opposing portion including the first flow path surface 41a at a portion excluding the region where the through hole 43 is formed. That is, the connecting portion 40a is arranged around the opposing portion.

Further, the flow path plate 40 is connected to the first housing member 20A (and the second housing member 20B) by the connecting portion 40a except for the area where the through hole 43 is formed. Note that the channel plate 40 may be a single plate-shaped member in which the connecting portion 40a is integrally formed.

The through hole 43 becomes a channel through which fluid flows. That is, the through hole 43 communicates the space E1 facing the first flow path surface 41a with the space E3 facing the second flow path surface 41b forming the opposite surface to the first flow path surface 41a.

A plurality of through holes 43 may be arranged concentrically with the actuator element 30 at equal intervals. Although the through hole 43 has a substantially rectangular shape in plan view in this embodiment, it is not limited to this, and may have various shapes such as circular, elliptical, semicircular, etc. in plan view. can be formed. Further, as the material of the channel plate 40 including the connecting portion 40a, for example, resin, metal, etc. can be used.

The pump 11A of this embodiment configured as described above transports fluid as follows.
A voltage is applied to the electrodes 38a, 38b of the vibration element 36 via the wirings 51a, 51b. This causes the vibration element 36 to vibrate. The vibration of the vibration element 36 causes the actuator element 30 to vibrate (bending motion).

When the actuator element 30 vibrates, fluid flows from the first opening 21 through the through hole 31 of the actuator element 30 and is introduced into the housing 20 . The fluid flows through the space E1 between the second main surface 32b of the actuator element 30 and the first flow path surface 41a of the flow path plate 40. The fluid that has passed through the expanded portion E2 of the space E1 then flows from the through hole 43 of the flow path plate 40 through the space E3 between the second flow path surface 41b and the inner surface 20B1 of the second housing member 20B, and flows through the second opening. It is supplied to the container 2 through the hole 22.

Due to such a fluid flow, the fluid in the expanded portion E2 of the space E1 causes Helmholtz resonance. By matching the Helmholtz resonance frequency with the operating frequency of the vibration element, it becomes possible to improve the suction capacity of the pump 11A.

After the container 2 is filled with fluid, when the actuator element 30 stops vibrating, the fluid stored in the container 2 flows back into the pump 11A and is discharged from the through hole 31. At this time, the actuator element 30 receives a force in the direction of pushing the support member 50 toward the protrusion (position regulating part) 26 due to the pressure of the fluid, and the distance (space) between the actuator element 30 and the channel plate 40 E1 and extension E2) do not change, allowing rapid evacuation of fluid.

In the fluid control device 1A of this embodiment configured as described above, the actuator element 30 of the pump 11A is connected to the protrusion (position regulating portion) 26. That is, in this embodiment, the actuator element 30 is connected to the protrusion (position regulating part) 26 via the support member 50, and the through hole 31 faces the first opening 21 of the third housing member 20C. Further, the channel plate 40 is disposed at a position facing the second main surface 32b of the actuator element 30 with a space E1 in between.

Further, in the fluid control device 1A of the present embodiment, the protrusion (position regulating portion) 26 of the pump 11A is located inside the node N that occurs when the actuator element 30 vibrates at its natural frequency, that is, at the center of the actuator element 30. At the closer position, the supporting member 50 is in contact with a surface opposite to the surface joined to the actuator element 30 and is connected to the actuator element 30 .

In the pump 11A having such a configuration, when the actuator element 30 vibrates at the operating frequency (bending vibration), the amount of displacement near the center of the actuator element 30 is approximately the same as the amount of displacement near the periphery of the actuator element 30. It can be made into Therefore, the accuracy of the gap between the actuator element 30 and the flow path plate 40 when the actuator element 30 vibrates (bending vibration) increases, and high pump performance can be achieved.

Further, in the fluid control device 1A of the present embodiment, the protrusion (position regulating portion) 26 is spaced apart from the support member 50 at the node N and closer to the periphery than the node N. Therefore, since the displacement of the actuator element 30 on the periphery side from the node N is suppressed from being restricted, the amount of displacement near the center of the actuator element 30 and the amount of displacement near the periphery of the actuator element 30 can be more reliably made to be approximately the same. It can be made into

(Second embodiment)
FIG. 7 is a sectional view of a fluid control device according to a second embodiment.
In addition, in the following description, the same numbers are attached to the same components as in the first embodiment described above, and redundant description will be omitted.
A pump 11B constituting a fluid control device 1B according to the second embodiment has an actuator element 60 formed inside a housing 20.

The actuator element 60 of this embodiment includes an elastic substrate (substrate) 65 and a vibration element 66 arranged on the surface (lower surface) of the elastic substrate 65. The elastic substrate 65 is preferably made of a material that is capable of bending vibration due to the vibration of the vibration element 66 and is difficult to attenuate the vibration energy of the vibration element 66. Examples of the material of the elastic substrate 65 include silicon, iron, Phosphor bronze or the like can be used. The vibrating element 66 is a piezoelectric vibrator including a thin film piezoelectric material 67 and electrodes 68a and 68b arranged on the upper and lower surfaces of the thin film piezoelectric material 67. Note that the vibrating element 66 may be a piezoelectric vibrator laminate in which two or more piezoelectric vibrators are laminated.

In this embodiment, the outer edge of the vibrating element 66 is formed inside the outer edge of the elastic substrate 65 in the surface spreading direction f perpendicular to the thickness direction t. That is, the outer edge of the vibration element 66 is located inside the outer edge of the elastic substrate 65 when viewed from the opposing direction of the first main surface 32a and the second main surface 32b of the actuator element 30 (thickness direction t in FIG. 7). Specifically, the elastic substrate 65 is formed to have a larger diameter than the vibration element 66.

In such an actuator element 60, the surface (lower surface) of the vibration element 66 connected to the protrusion (position regulating part) 26 via the support member 50 is the first main surface 62a, and the surface on the opposite side thereof is the first main surface 62a. The surface (upper surface) of a certain elastic substrate 65 forms the second main surface 62b.

A through hole 61 is formed in the actuator element 60, passing through between the first main surface 62a and the second main surface 62b. The through hole 61 is composed of a first aperture region 65A formed in the vibration element 66 and a second aperture region 65B continuous with the first aperture region 65A and formed in the elastic substrate 65. . Such a through hole 61 is formed such that the opening diameter of the first opening area 65A formed in the vibration element 66 is larger than the opening diameter of the second opening area 65B formed in the elastic substrate 65. ing.

Further, in the flow path plate 70 of this embodiment, the first flow path surface 71a facing the actuator element 60 is a flat surface, and no recesses are formed as in the first embodiment. Therefore, no expanded portion or the like is formed between the actuator element 60 and the first flow path surface 71a.

Also in this embodiment, the joint portion 53 where the actuator element 60 is joined to the support member 50 is formed closer to the center of the actuator element 60 than the node N. That is, the actuator element 60 is supported by the support member 50 on the inner side of the node N. Also in this embodiment, the protrusion (position regulating part) 26 is located inside the node N, that is, at a position near the center of the actuator element 30, opposite to the surface of the support member 50 that is joined to the actuator element 30. The actuator element 30 is connected to the actuator element 30 .

Even if the actuator element 60 is composed of a bonded elastic substrate 65 and vibration element 66 as in the present embodiment, the actuator element 30 vibrates at the operating frequency (flexural vibration) as in the first embodiment. When the actuator element 30 vibrates (bending vibration), the displacement amount near the center of the actuator element 30 and the displacement amount near the periphery of the actuator element 30 can be made almost the same. The accuracy of the gap between the channel plate 30 and the channel plate 40 is increased, and high pump performance can be achieved.

By configuring the actuator element 60 by joining the vibration element 66 and the elastic substrate 65 as in this embodiment, even if a thin film-like piezoelectric material 67 is used as the vibration element 66, the actuator element 60 can be Able to maintain physical strength. Further, by using the thin film piezoelectric body 67, it is possible to cope with high frequency vibrations, and the actuator element 60 can be driven more efficiently.

Further, as in this embodiment, the outer edge of the vibration element 66 is located inside the outer edge of the elastic substrate 65 when viewed from the opposing direction of the first main surface 32 a and the second main surface 32 b of the actuator element 30 . Therefore, since the vibration element 66 is reliably fixed to the elastic substrate 65, reliability can be improved.

(Third embodiment)
FIG. 8 is a sectional view of a fluid control device according to a third embodiment. 9(A) is a cross-sectional view taken along the line AA in FIG. 8, (B) is a cross-sectional view taken along the line B-B in FIG. 8, and (C) is a cross-sectional view taken along the line CC in FIG. be.
In addition, in the following description, the same numbers are attached to the same components as in the first embodiment described above, and redundant description will be omitted.
A fluid control device 1C according to the third embodiment includes a pump 11A, a container 2, and a valve 3 disposed between the pump 11A and the container 2. The second embodiment is the same as the first embodiment except that the valve 3 is provided.

The valve 3 includes a cylindrical tube 81 that is open in the vertical direction, and a valve body 83 and a ball 86 that are arranged inside the cylindrical tube 81. The cylindrical tube 81 has an outlet 82 connected to the outside. The valve body 83 has a first passage hole 84 that is closed in the vertical direction, and a second passage hole 85 that is open downward at one end and connected to the outlet 82 at the other end. have The ball 86 is arranged below the valve body 83.

In the valve 3 having such a configuration, when the pump 11A is driven to store fluid in the container 2, the ball 86 is pushed by the fluid sent from the pump 11A and moves upward to the second channel hole. By closing the lower gate 85 , fluid is sent to the container 2 through the first channel hole 84 .

On the other hand, when the pump 11A is stationary and the fluid stored in the container 2 is taken out, the ball 86 moves downward and closes the second opening 22 of the pump 11A. As a result, the fluid flows below the valve body 83 through the first passage hole 84 , and the fluid that flows below the valve body 83 passes through the second passage hole 85 and flows through the outlet 82 . and then taken out to the outside.

According to the fluid control device 1C of the present embodiment configured as described above, the valve 3 connecting the pump 11A and the container 2 is provided. It can be taken out.

(Configuration example)
As one configuration example, a pump includes an actuator element having a first main surface and a second main surface facing each other, and a facing portion including a first surface facing the second main surface of the actuator element with a space therebetween. a housing that accommodates the actuator element and the facing portion of the first plate inside, and a protrusion protruding from the housing toward the inside of the housing, the protrusion is connected to the actuator element at a position closer to the center of the actuator element than a node portion that occurs when the actuator element vibrates at a natural frequency.

As one configuration example, in the pump, the protruding portion may be spaced apart from the actuator element at the node portion.

As one configuration example, in the pump, the actuator element may have a through hole that penetrates between the first main surface and the second main surface.

As a configuration example, in a pump, the actuator element may include a substrate forming the second main surface, and a vibration element forming the first main surface and bonded to the substrate. .

As a configuration example, in the pump, the outer edge of the vibrating element may be located inside the outer edge of the substrate when viewed from a direction in which the first main surface and the second main surface face each other.

As one configuration example, in the pump, the first plate has a connecting part connected to the opposing part, and the housing has a cylindrical first housing member connected to the connecting part. Good too.

As one configuration example, in a pump, the housing includes a third housing member that has a first opening and is connected to the first housing member, and the protrusion portion is connected to the third housing member. May be connected.

As one configuration example, the pump further includes a support member that supports the actuator element, the support member is connected to the first housing member, and the protrusion is connected to the actuator element through the support member. The support member may be connected to an actuator element, and may be in contact with a surface of the support member opposite to a surface to be joined to the actuator element at a position closer to the center of the actuator element than the node portion.

As one configuration example, in the pump, the support member has a drawer portion extending to the outside of the first housing member, the support member is spaced apart from the actuator element at the node portion, and the support member The joint portion where the member and the actuator element are joined and the pull-out portion may be located on the same plane.

As one configuration example, in a pump, the support member may have power supply wiring that supplies power to the actuator element.

As one configuration example, in the pump, the power supply wiring may be electrically connected to the actuator element closer to the center of the actuator element than the node portion.

As one configuration example, in the pump, the housing is connected to the first housing member and has a second housing that has an inner surface that extends so as to face a second surface that is opposite to the first surface of the first plate. The second housing member may have a second aperture extending between the inner surface and the opposite surface.

As one configuration example, the fluid control device may include the pump described above, and may include a container into which fluid flows in and out through the second opening.

As one configuration example, in the fluid control device, a valve may be formed between the pump and the container.

Although one embodiment of the technology according to the present disclosure has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. This embodiment and its modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

1A, 1B, 1C Fluid control device 2 Container (tank)
3 Valve 11A, 11B, 11C Pump 20 Housing 20A First housing member 20B Second housing member 20C Third housing member 21 First opening (first opening)
22 Second opening part (second opening)
26 Projection (position regulating part)
30 Actuator element 31 Through hole 32a First main surface 32b Second main surface 36 Vibration element 37 Plate piezoelectric body 38a, 38b Electrode 40 Channel plate 41a First channel surface 41b Second channel surface 42 Recess 50 Support member 51a, 51b Wiring 52 Through hole 53 Joint part E1 Space E2 Extension part N Node (node part)

Claims (14)

an actuator element having a first main surface and a second main surface facing each other;
a first plate having a facing portion including a first surface facing the second main surface of the actuator element with a space therebetween;
a housing that accommodates the actuator element and the facing portion of the first plate therein;
a protrusion protruding from the housing toward the inside of the housing,
The pump is characterized in that the protruding portion is connected to the actuator element at a position closer to the center of the actuator element than a node portion that occurs when the actuator element vibrates at a natural frequency. The pump according to claim 1, wherein the protruding portion is spaced apart from the actuator element at the node portion. The pump according to claim 1 or 2, wherein the actuator element has a through hole passing through between the first main surface and the second main surface. 4. The actuator element includes a substrate forming the second main surface and a vibration element forming the first main surface and bonded to the substrate. The pump described in paragraph 1. The pump according to claim 4, wherein an outer edge of the vibrating element is located inside an outer edge of the substrate when viewed from a direction in which the first main surface and the second main surface face each other. The first plate has a connecting part connected to the opposing part,
The pump according to any one of claims 1 to 5, wherein the housing has a cylindrical first housing member connected to the connecting portion. The housing includes a third housing member having a first opening and connected to the first housing member;
7. The pump according to claim 6, wherein the protrusion is connected to the third housing member. further comprising a support member that supports the actuator element,
the support member is connected to the first housing member,
The protrusion is connected to the actuator element via the support member, and is connected to a surface of the support member to be joined to the actuator element at a position closer to the center of the actuator element than the node part. 8. The pump according to claim 6, wherein the pump is in contact with opposite surfaces. The support member has a drawer portion extending to the outside of the first housing member,
The support member is spaced apart from the actuator element at the node portion,
9. The pump according to claim 8, wherein a joint portion where the support member and the actuator element are joined and the draw-out portion are located on the same plane. The pump according to claim 8 or 9, wherein the support member has a power supply wiring that supplies power to the actuator element. The pump according to claim 10, wherein the power supply wiring is electrically connected to the actuator element closer to the center of the actuator element than the node portion. The housing has a second housing member connected to the first housing member and having an inner surface that extends to face a second surface opposite to the first surface of the first plate,
12. A pump according to any one of claims 6 to 11, wherein the second housing member has a second aperture extending between the inner surface and the opposite surface. A fluid control device comprising the pump according to claim 12,
A fluid control device comprising a container into which fluid flows in and out through the second opening. 14. The fluid control device according to claim 13, wherein a valve is formed between the pump and the container.

Images