JP2023126989A - Pump and fluid control device - Google Patents

Abstract

To provide a pump and a fluid control device which are adaptable to downsizing.SOLUTION: The pump includes: an actuator element 30 having a first principal surface 32a and a second principal surface 32b opposed to each other, and a first through-hole 31 penetrating through between the first principal surface 32a and the second principal surface 32b; a first plate 40 having an opposed portion including a first surface 41a opposed to the second principal surface 32b of the actuator element 30 via a space E1, and a first plate 40a connected to the opposed portion and having a second through-hole 43; a cylindrical first housing member 20A connected to the connection portion 40a; and a support member 50 connecting the actuator element 30 and the first housing member 20A and supporting the actuator element 30 inside the first housing member 20A.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 technology disclosed in Patent Document 1, a piezoelectric pump has a structure in which a piezoelectric pump has a flexible plate provided with a suction hole on the bottom side of the piezoelectric actuator, and a lid plate provided with a discharge hole on the top side of the piezoelectric actuator. It becomes. The piezoelectric pump also has a valve that allows gas to be evacuated from the cuff. This valve fills the cuff with compressed air and then rapidly evacuates the air from the cuff. As a result, the cuff deflates rapidly, so that the next blood pressure measurement can be started immediately.

Here, further miniaturization of small pumps using actuator elements is desired. However, in the technology disclosed in Patent Document 1, when the cuff is directly connected to the discharge hole of the piezoelectric pump without using a valve to reduce the size (reducing the height), after filling the cuff with compressed air, the piezoelectric pump When the drive is stopped, air flows back into the piezoelectric pump and the piezoelectric actuator approaches the flexible plate. As a result, there was a possibility that the suction hole would be blocked by the piezoelectric actuator, making it impossible to exhaust the air.

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 can be made smaller.

In one aspect of the present disclosure, the pump has a first main surface and a second main surface facing each other, and has a first through hole that penetrates between the first main surface and the second main surface. A first plate having an actuator element, a facing part including a first surface facing the second main surface of the actuator element via space, and a connecting part connected to the facing part and having a second through hole. a cylindrical first housing member connected to the connecting portion; a support member connecting the actuator element and the first housing member and supporting the actuator element inside the first housing member; have.

According to the technology according to the present disclosure, it is possible to provide a pump and a fluid control device that can be made smaller.

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. FIG. 2 is a schematic cross-sectional view illustrating the operating state of the actuator element shown in FIG. 1. FIG. In the fluid control device of the first embodiment, it is a graph showing the relationship between the diameter of the second opening, the pressure inside the container, and the air flow rate of the pump. 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. 7 is a graph showing the relationship between the diameter of the diaphragm opening, the pressure in the lower valve chamber, and the air flow rate in a conventional fluid control device.

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 a schematic cross-sectional view illustrating the operating state of the actuator element shown in FIG. 1.

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.
Furthermore, the housing 20 is formed so as to partially close the other open end of the first housing member 20A, and has a third housing member (position regulating member) that is a bottomed cylindrical body with a rectangular outer cross section and a rectangular inner cross section. )20C.

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.

A first opening portion (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 22 that passes through an inner surface 20B1 facing the channel plate 40 and an opposite surface 20B2. Thereby, when storing fluid in the container 2, the first opening 21 becomes a fluid introduction hole, and the second opening 22 becomes a fluid discharge hole. Moreover, when the fluid stored in the container 2 is discharged to the outside, the first opening 21 becomes a fluid discharge hole, and the second opening 22 becomes a fluid introduction hole.

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.

The actuator element 30 has a through hole (first through hole) 31 . 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.

The support member 50 that supports the actuator element 30 has a surface opposite to the surface joined to the actuator element 30 that is in contact with the protrusion (position restriction part) 26 of the third housing member (position restriction member) 20C that constitutes the housing 20. , and the through hole 31 is arranged at a position communicating with the first opening 21 of the third housing member 20C.

The protruding part (position regulating part) 26 of the third housing member (position regulating member) 20C is arranged around the first opening part 21, and extends from the third housing member (position regulating member) 20C to the inside of the housing 20. protruding toward In addition. 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. The protruding part (position regulating part) 26 may be configured as a separate member from the third housing member (position regulating member) 20C.

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.

FIG. 6 shows a state in which the actuator element 30 is vibrating. The node N that occurs when the actuator element 30 vibrates at its natural frequency is in contact with the protrusion (position regulation part) 26 via the support member 50, or the node N is in contact with the protrusion (position regulation part) 26 via the support member 50. ) 26 is preferable.

In this embodiment, the actuator element 30 is in contact with the protrusion (position regulation part) 26 of the third housing member (position regulation member) 20C via the support member 50, and the elastic force of the support member 50 causes the actuator element 30 to be in contact with the protrusion (position regulation part) 26 of the third housing member (position regulation member) 20C. (position regulating part) 26, and are configured so as not to be separated from each other.

Hereinafter, in this embodiment, the surface of the actuator element 30 on the side that is in contact with the protrusion (position regulating part) 26 of the third housing member (position regulating member) 20C is the first main surface 32a, and the surface on the opposite side is the first main surface 32a. It may be referred to as the second principal 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 (first surface) 41a. There is. 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. The opposing portion of the channel plate 40 is housed inside the housing 20 .

It is preferable that 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 concave portion 42 forms an expanded portion E2 in the space E1 with an expanded cross-sectional area in a direction perpendicular to the direction in which the fluid flows.

With such a configuration, even when 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 (second 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 (see FIG. 3), and the periphery on the center side of the pump 11A overlaps the periphery of the actuator element 30, and the The outer periphery of 11A is located at a distance from 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 (second 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. For example, resin, metal, etc. can be used as the material of the channel plate 40 including the connecting portion 40a.

The support member 50 includes wiring lines 51a and 51b. The wiring 51a and the wiring 51b extend in opposite directions. The support member 50 may be 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.

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 piezoelectric plate 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 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.

Here, in the fluid control device 1A including the pump 11A of this embodiment, the effect of eliminating the need for a valve will be explained in detail.

First, the configuration of a conventional fluid control device including a valve will be described. In a conventional fluid control device, for example, the piezoelectric pump described in Patent Document 1, the top surface of the piezoelectric pump is joined to the bottom surface of the valve, so that the valve is connected to the piezoelectric pump, and the cuff is attached to the cuff connection port of the valve. The cuff is connected to the valve by being connected to the valve. The piezoelectric pump has a structure in which a flexible plate is provided with a suction hole on the bottom side of the piezoelectric actuator, and a cover plate is provided with a discharge hole on the top side of the piezoelectric actuator.

The valve includes a first ventilation hole communicating with the discharge hole of the piezoelectric pump, a second ventilation hole communicating with the internal space of the cuff, a third ventilation hole communicating with the outside, a first valve seat, and a third ventilation hole. The present invention includes a valve housing having a second valve seat protruding from around the pore, and a diaphragm fixed to the valve housing having an opening. The diaphragm forms a lower valve chamber communicating with the first vent hole and an upper valve chamber communicating with the second vent hole and the third vent hole.

In such conventional fluid control devices, when the piezoelectric pump is driven, air flows into the lower valve chamber through the first ventilation hole, the pressure in the lower valve chamber becomes higher than the pressure in the upper valve chamber, and the diaphragm closes. Contact with the second valve seat blocks the third vent hole, and movement away from the first valve seat allows air to be delivered to the cuff through the opening in the diaphragm. On the other hand, when the piezoelectric pump stops driving, the pressure in the lower valve chamber becomes lower than the pressure in the upper valve chamber, and the diaphragm separates from the second valve seat, opens the third vent hole, and passes through the first valve seat. The contact closes the opening in the diaphragm and air in the cuff is rapidly evacuated through the third vent.

FIG. 10 is a graph showing the relationship between the diameter of the opening of the diaphragm and the pressure in the lower valve chamber (solid line) and the relationship with the air flow rate (dashed line) in the piezoelectric pump described in Patent Document 1. In FIG. 10, the horizontal axis represents the diameter of the opening of the diaphragm (μm), the left vertical axis represents the pressure in the lower valve chamber (kPa), and the right vertical axis represents the flow rate during operation (ml/min). Note that the piezoelectric actuator was disk-shaped (diameter: 12 mm). The distance between the piezoelectric actuator and the flexible plate was 10 μm.

The graph of FIG. 10 shows that in the conventional fluid control device, as the diameter of the diaphragm opening increases, the flow rate increases, while the pressure in the lower valve chamber decreases. That is, in the conventional fluid control device, when trying to send air to the cuff, it is necessary to make the pressure in the lower valve chamber higher than the pressure in the upper valve chamber, and in order to avoid a drop in the pressure in the lower valve chamber, It can be seen that the diameter of the diaphragm opening cannot be increased and the flow rate cannot be increased.

This is because a valve is required that includes a diaphragm that forms a lower valve chamber communicating with the first vent and an upper valve chamber communicating with the second and third vents. If the valve is removed in a conventional fluid control device, when the piezoelectric pump stops driving after filling the cuff with compressed air, air flows back into the piezoelectric pump and the piezoelectric actuator approaches the flexible plate. As a result, the piezoelectric actuator may block the suction hole, making it impossible to exhaust the air. Therefore, a valve with an exhaust vent is required, the diameter of the diaphragm opening cannot be increased, and the flow rate cannot be increased.

FIG. 7 shows the relationship (solid line) between the diameter of the second opening 22 and the pressure inside the container (tank) 2, and the relationship (solid line) with the air flow rate of the pump 11A in the fluid control device 1A of the first embodiment. FIG. In FIG. 7, the horizontal axis is the diameter (μm) of the second opening 22, the left vertical axis is the pressure (kPa) in the pump container (tank), and the right vertical axis is the air flow rate (ml) during operation. /min). Note that the actuator element 30 had a disk shape (diameter: 12 mm). The opening height of the space E1 (the distance between the second main surface 32b of the actuator element 30 and the first channel surface 41a of the channel plate 40) was set to 10 μm. In addition, in this embodiment, the opening of the diaphragm of the conventional example corresponds to the second opening 22. Further, according to FIG. 7, when the diameter of the second opening is set to 200 μm or more, the pressure and flow rate converge to a constant value, and each becomes a high value.

From the graph of FIG. 7, the fluid control device 1A including the pump 11A of this embodiment does not require the valves in the conventional fluid control device by forming the through hole 31 in the actuator element 30. Therefore, the aperture diameter of the second aperture portion 22 can be expanded to increase the flow rate.

In the fluid control device 1A of this embodiment configured as described above, the actuator element 30 of the pump 11A has the through hole 31, and the flow path plate 40 is connected to the second main surface 32b of the actuator element 30 via the space E1. It has a facing part including a first surface facing each other, and a connecting part connected to the facing part and having a through hole 43. It also has a cylindrical first housing member 20A that is connected to the connecting portion of the flow path plate 40, and the support member 50 supports the actuator element 30 inside the first housing member 20A.

In addition, in the fluid control device 1A of the present embodiment, the support member 50 that supports the actuator element 30 of the pump 11A has a surface opposite to the surface joined to the actuator element 30, and a protrusion (position regulating portion) of the third housing member 20C. ) 26 and the through hole 31 is arranged at a position facing the first opening 21 of the third housing member 20C.

In the pump 11A having such a configuration, when the actuator element 30 vibrates, the center of the actuator element 30 near the through hole 31 that is close to or away from the flow path plate 40 and the flow path are in opposite phase to the center. The vicinity of the periphery of the actuator element 30 that is spaced from or close to the plate 40 functions as a valve. That is, the vicinity of the center and the vicinity of the periphery of the actuator element 30 form a valve structure that functions in conjunction with the resonance vibration of the actuator element 30. This provides a valve opening/closing function that operates reliably even at high vibration velocities above the audible range (20 kHz or above), making it possible to exhibit high pumping performance.

In addition, in the pump 11A having such a configuration, even if the pressure inside the pump 11A increases, the through hole 31 is not blocked by this pressure increase, so that the pump 11A does not pump into the container (tank) 2. It becomes possible to store the fluid and discharge the fluid in the container (tank) 2. That is, since the fluid control device 1A of this embodiment can eliminate the need for a valve, it can be made smaller, lower in cost, and higher in performance.

Furthermore, since the fluid control device 1A having such a configuration does not require a valve, the diameter of the second opening 22 can be increased without being restricted. As a result, it becomes possible to realize a fluid control device that generates a large flow rate at high pressure.

(Second embodiment)
FIG. 8 is a sectional view of the fluid control device according to the 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 such an actuator element 60, the surface (lower surface) of the vibration element 66 is the first main surface 62a, and the surface (upper surface) of the elastic substrate 65, which is the surface on the opposite side thereof, is the second main surface 62b. I will do it.

A through hole (first 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, the central axis of the first aperture region 65A and the central axis of the second aperture region 65B are formed to be on the same axis S.

Note that when the first aperture region 65A and the second aperture region 65B are holes with a circular cross section as in the present embodiment, the aperture diameter may be a diameter, but the first aperture region and the second aperture region When the region 65B is a hole with a rectangular or polygonal cross section, the opening diameter may be the maximum diameter (maximum opening diameter).

Even if the actuator element 60 is composed of an elastic substrate 65 and a vibrating element 66 bonded together as in the present embodiment, the high vibration speed above the audible band (20 kHz or above) can be achieved similarly to the pump of the first embodiment. Since it has a valve opening/closing function that works reliably even in the middle of the day, it can demonstrate high pumping capacity. In addition, it is possible to realize a pump 11C that can store fluid in the container (tank) 2 and discharge the fluid in the container (tank) 2, and eliminates the need for valves, resulting in smaller size, lower cost, and higher performance. can be achieved. Furthermore, since there is no need to provide a valve, the diameter of the second opening 22 can be increased without being restricted, making it possible to realize a fluid control device that generates a large flow rate at high pressure.

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.

Furthermore, as in the present embodiment, by making the opening diameter of the first opening region 65A formed in the vibration element 66 larger than the opening diameter of the second opening region 65B formed in the elastic substrate 65, Compared to the case where the openings are formed to have the same diameter, the vibration element 66 is firmly fixed to the elastic substrate 65, so that reliability can be improved.

Furthermore, in the actuator element 60, by making the opening diameter of the first opening area 65A, which is the suction side during suction, larger than the opening diameter of the second opening area 65B, when the fluid flows in the suction direction, In comparison, fluid resistance when fluid flows backward can be increased. This makes it possible to improve pump performance.

(Third embodiment)
FIG. 9 is a sectional view of a fluid control device according to a third 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 11C constituting a fluid control device 1C according to the third embodiment has an actuator element 70 formed inside a housing 20.

The actuator element 70 of this embodiment includes an elastic substrate (substrate) 75 and a vibration element 76 arranged on the surface (upper surface) of the elastic substrate 75. The elastic substrate 65 is preferably made of a conductive material that is capable of bending vibration due to the vibration of the vibration element 76 and is difficult to attenuate the vibration energy of the vibration element 76. Examples of the material of the elastic substrate 75 include iron, iron, Phosphor bronze or the like can be used. The vibrating element 76 is a piezoelectric vibrator including a thin film piezoelectric material 77 and electrodes 78a and 78b arranged on the upper and lower surfaces of the thin film piezoelectric material 77. In this embodiment, one electrode 78b of the vibrating element 76 is connected to the wiring 51a via an elastic substrate 75 made of a conductive material.

In such an actuator element 70, one surface (lower surface) of the elastic substrate 75 is the first main surface 72a, and the surface (upper surface) of the vibration element 76, which is the opposite surface, is the second main surface. 72b. That is, the actuator element of the second embodiment has a configuration in which the formation positions of the elastic substrate and the vibration element are reversed.

A through hole (first through hole) 71 is formed in the actuator element 70 and penetrates between the first main surface 72a and the second main surface 72b. The through hole 71 is composed of a first aperture region 75A formed in the vibration element 76 and a second aperture region 75B continuous with the first aperture region 75A and formed in the elastic substrate 75. .

In this embodiment, the opening diameter of the first opening region 75A and the opening diameter of the second opening region 75B formed in the elastic substrate 75 are formed to be the same size. Further, the central axis of the first aperture region 75A and the central axis of the second aperture region 75B are formed to be on the same axis S.

As in this embodiment, even if the actuator element 70 is composed of an elastic substrate 75 and a vibrating element 76 bonded together, and the vibrating element 76 is placed in a position facing the first flow path surface 41a of the flow path plate 40, Like the pump of the first embodiment, it has a valve opening/closing function that operates reliably even at high vibration speeds above the audible range (20 kHz or above), so it can exhibit high pumping performance. In addition, it is possible to realize a pump 11C that can store fluid in the container (tank) 2 and discharge the fluid in the container (tank) 2, and eliminates the need for valves, resulting in smaller size, lower cost, and higher performance. can be achieved. Furthermore, since there is no need to provide a valve, the diameter of the second opening 22 can be increased without being restricted, making it possible to realize a fluid control device that generates a large flow rate at high pressure.

(Configuration example)
As one configuration example, in a pump, an actuator element has a first main surface and a second main surface facing each other, and has a first through hole penetrating between the first main surface and the second main surface. a first plate having a facing portion including a first surface facing the second main surface of the actuator element with a space therebetween; and a connecting portion connected to the facing portion and having a second through hole; A cylindrical first housing member connected to the connecting portion, and a support member connecting the actuator element and the first housing member and supporting the actuator element inside the first housing member. are doing.

In one configuration example, the first through hole may be located at the center of the actuator element.

As one configuration example, 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 one configuration example, the first through hole may include a first aperture region of the vibrating element and a second aperture region of the substrate that is continuous with the first aperture region.

As one configuration example, the aperture diameter of the first aperture region may be larger than the aperture diameter of the second aperture region.

As one configuration example, the central axis of the first aperture region and the central axis of the second aperture region may be on the same axis.

As one configuration example, the support member may be arranged so as to cover the entire area between the actuator element and the first housing member when the support member is viewed from the first plate. .

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

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

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, 1D Fluid control device 2 Container (tank)
11A, 11B, 11C, 11D Pump 20 Housing 20A First housing member 20B Second housing member 20C Third housing member 21 First opening (opening)
22 Second opening portion 26 Projection portion (position regulating portion)
30 Actuator element 31 Through hole (first 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 43 Through hole (second through hole)
50 Support member 51a, 51b Wiring E1 Space E2 Expansion part

Claims (9)

an actuator element having a first main surface and a second main surface facing each other, and a first through hole penetrating between the first main surface and the second main surface;
a first plate having a facing portion including a first surface facing the second main surface of the actuator element with a space therebetween; and a connecting portion connected to the facing portion and having a second through hole;
a cylindrical first housing member connected to the connecting portion;
a support member that connects the actuator element and the first housing member and supports the actuator element inside the first housing member;
A pump characterized by having. The pump according to claim 1, wherein the first through hole is located at the center of the actuator element. 3. 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. pump. 4. The first through-hole is comprised of a first aperture region of the vibration element and a second aperture region of the substrate that is connected to the first aperture region. pump. 5. The pump according to claim 4, wherein an aperture diameter of the first aperture region is larger than an aperture diameter of the second aperture region. The pump according to claim 4 or 5, wherein the central axis of the first aperture region and the central axis of the second aperture region are coaxial. The supporting member is arranged so as to cover the entire area between the actuator element and the first housing member when the supporting member is viewed in plan from the first plate. 7. The pump according to any one of 1 to 6. 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;
8. A pump according to any one of claims 1 to 7, wherein the second housing member has an aperture extending between the inner surface and the opposite surface. A fluid control device comprising the pump according to claim 8,
A fluid control device comprising a container into which fluid flows in and out through the opening.

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