FLUID CONTROL APPARATUS AND ELECTRONIC APPARATUS

Abstract

A fluid control apparatus includes a flow-path space forming portion, an inflow opening, an outflow opening, and a drive mechanism. The flow-path space forming portion includes a flexible portion that have flexibility, and a facing portion that faces the flexible portion, the flow-path space forming portion forming a flow path space between the flexible portion and the facing portion, the flow path space being a flow path of fluid. The inflow opening is provided to an outer peripheral portion of the flow path space, as viewed from a facing direction in which the flexible portion and the facing portion face each other, the inflow opening being an opening through which the fluid flows into the flow path space. The outflow opening is provided to a portion, in the outer peripheral portion of the flow path space, that is different from a portion, in the outer peripheral portion of the flow path space, that is provided with the inflow opening, as viewed from the facing direction, the outflow opening being an opening through which the fluid flows out of the flow path space. The drive mechanism bends the flexible portion to increase or decrease the volume of the flow path space. Further, the flexible portion is configured such that at least a portion of a region of the flexible portion is curved toward the facing portion to have a concave shape in a reference state in which the flexible portion is not bent by the drive mechanism, the region of the flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

Description

TECHNICAL FIELD

The present technology relates to a fluid control apparatus that transfers fluid, and an electronic apparatus.

BACKGROUND ART

For example, a diaphragm-type pump that uses a diaphragm has been put into practical use as a small and thin pump (for example, refer to Patent Literature 1). The diaphragm-type pump includes a pump room of which the volume varies due to a diaphragm being bent to be deformed, and enables fluid to be intaken into the pump room by increasing the volume of the diaphragm-type pump, and enables fluid to be discharged from the pump room by decreasing the volume of the diaphragm-type pump.

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Patent Application Laid-open No. 2011-256741

DISCLOSURE OF INVENTION

Technical Problem

With respect to fluid control apparatuses as disclosed in Patent Literature 1, there is a need for a technology that makes it possible to provide a smaller fluid control apparatus that exhibits a higher performance.

In view of the circumstances described above, it is an object of the present technology to provide a small fluid control apparatus that exhibits a high performance, and an electronic apparatus that uses the fluid control apparatus.

Solution to Problem

In order to achieve the object described above, a fluid control apparatus according to an embodiment of the present technology includes a flow-path space forming portion, an inflow opening, an outflow opening, and a drive mechanism.

The flow-path space forming portion includes a flexible portion that have flexibility, and a facing portion that faces the flexible portion, the flow-path space forming portion forming a flow path space between the flexible portion and the facing portion, the flow path space being a flow path of fluid.

The inflow opening is provided to an outer peripheral portion of the flow path space, as viewed from a facing direction in which the flexible portion and the facing portion face each other, the inflow opening being an opening through which the fluid flows into the flow path space.

The outflow opening is provided to a portion, in the outer peripheral portion of the flow path space, that is different from a portion, in the outer peripheral portion of the flow path space, that is provided with the inflow opening, as viewed from the facing direction, the outflow opening being an opening through which the fluid flows out of the flow path space.

The drive mechanism bends the flexible portion to increase or decrease the volume of the flow path space.

Further, the flexible portion is configured such that at least a portion of a region of the flexible portion is curved toward the facing portion to have a concave shape in a reference state in which the flexible portion is not bent by the drive mechanism, the region of the flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

The flexible portion may be configured such that a center portion of the flexible portion as viewed from the facing direction is curved toward the facing portion to have a concave shape in the reference state.

The flexible portion may have a shape obtained by a plate member being deformed and curved toward the facing portion to have a concave shape in the reference state.

the drive mechanism may bend the flexible portion such that a concave portion of the flexible portion in the reference state is moved by a largest distance in the facing direction.

The drive mechanism may include a piezoelectric element that is connected to a certain surface of the flexible portion that is situated opposite to another surface of the flexible portion that faces the facing portion.

When the flexible portion is a first flexible portion, the facing portion may be a second flexible portion that has flexibility. In this case, the drive mechanism may bend the second flexible portion. Further, the second flexible portion may be configured such that at least a portion of a region of the second flexible portion is curved toward the first flexible portion to have a concave shape in the reference state, the region of the second flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

The first flexible portion and the second flexible portion may be configured to resonate with each other.

The drive mechanism may include a first piezoelectric element that is connected to a certain surface of the first flexible portion that is opposite to another surface of the first flexible portion that faces the second flexible portion, and a second piezoelectric element that is connected to a certain surface of the second flexible portion that is opposite to another surface of the second flexible portion that faces the first flexible portion. In this case, the drive mechanism may be configured such that a resonance frequency of the entirety of the first flexible portion and the first piezoelectric element is closer to a resonance frequency of the entirety of the second flexible portion and the second piezoelectric element.

when the flexible portion is a first flexible portion, the facing portion may be a second flexible portion that has flexibility. In this case, the first flexible portion and the second flexible portion may be configured to resonate with each other.

The drive mechanism may include a piezoelectric element that is connected to a certain surface of the first flexible portion that is situated opposite to another surface of the first flexible portion that faces the second flexible portion. In this case, the drive mechanism may be configured such that a resonance frequency of the second flexible portion is closer to a resonance frequency of the entirety of the first flexible portion and the first piezoelectric element.

The second flexible portion may have a larger thickness than the first flexible portion.

The second flexible portion may be configured such that the at least the portion of the region of the second flexible portion is curved toward the first flexible portion to have a concave shape in the reference state, the region of the second flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

The flexible portion may include a groove that is formed near an outer peripheral portion of the flexible portion, as viewed from the facing direction.

The drive mechanism may include a piezoelectric element that is connected to a certain surface of the flexible portion that is situated opposite to another surface of the flexible portion that faces the facing portion. In this case, the groove may be formed at a position based on an outer peripheral portion of the piezoelectric element, as viewed from the facing direction.

The fluid control apparatus may further include an inlet, an intake space forming portion, an outlet, and a discharge space forming portion.

The fluid is intaken into the fluid control apparatus though the inlet.

The intake space forming portion forms an intake space through which the inlet and the inflow opening communicate with each other.

The fluid is discharged from the fluid control apparatus through the outlet.

The discharge space forming portion forms a discharge space through which the outlet and the outflow opening communicate with each other.

The flow-path space forming portion may include a first plate member that is made of a metallic material and includes the flexible portion in a center region of the first plate member, as viewed from the facing direction, a second plate member that is made of a metallic material and includes the facing portion in a center region of the second plate member, as viewed from the facing direction, and a spacer member that has a specified thickness and includes an opening in a center region of the spacer member, as viewed from the facing direction, the spacer member being arranged between the first plate member and the second plate member, the spacer member being joined to the first plate member and to the second plate member using diffused junction.

The spacer member may include an inlet opening that is configured to communicate with an outer peripheral portion of the center opening, and an outlet opening that is configured to communicate with the outer peripheral portion of the center opening, the outlet opening being provided to a portion, in the spacer member, that is different from a portion, in the spacer member, that is provided with the inlet opening.

An inlet through which the fluid is intaken into the fluid control apparatus may be formed in at least one of a region, in the first plate member, that covers the inlet opening, or a region, in the second plate member, that covers the inlet opening. In this case, an outlet through which the fluid is discharged from the fluid control apparatus may be formed in at least one of a region, in the first plate member, that covers the outlet opening, or a region, in the second plate member, that covers the outlet opening.

An electronic apparatus according to an embodiment of the present technology includes the fluid control apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a fluid control apparatus according to a first embodiment, as viewed from diagonally above on the left.

FIG. 2 is a top view of the fluid control apparatus as viewed from above.

FIG. 3 is a set of cross-sectional views along the line A-A illustrated in FIG. 2.

FIG. 4 schematically illustrates an example of a configuration of a drive mechanism.

FIG. 5 schematically illustrates an example of a method for connecting a piezoelectric element to an upper surface member.

FIG. 6 is a set of schematic diagrams used to describe an initial volume.

FIG. 7 is a top view of a fluid control apparatus according to a second embodiment, as viewed from above.

FIG. 8 is a cross-sectional view along the line B-B illustrated in FIG. 7.

FIG. 9 individually illustrates respective members that are included in the fluid control apparatus.

FIG. 10 is a set of schematic diagrams used to describe a method for producing the fluid control apparatus.

FIG. 11 schematically illustrates an example of a method for connecting a first piezoelectric element to a first flexible portion and connecting a second piezoelectric element to a second flexible portion.

FIG. 12 schematically illustrates an example of a flow of fluid upon a pumping operation.

FIG. 13 is a set of schematic diagrams used to describe an initial volume.

FIG. 14 is a set of tables used to describe the initial volume.

FIG. 15 schematically illustrates examples of a configuration of a fluid control apparatus according to a third embodiment.

FIG. 16 schematically illustrates examples of a configuration of a fluid control apparatus according to other embodiments.

MODE(S) FOR CARRYING OUT THE INVENTION

Embodiments according to the present technology will now be described below with reference to the drawings.

First Embodiment

Example of Configuration of Fluid Control Apparatus

An example of a configuration of a fluid control apparatus according to a first embodiment of the present technology is described.

A fluid control apparatus 1 is a diaphragm-type fluid control apparatus, and serves as a pump that can intake and discharge fluid.

Note that examples of the fluid include gas, liquid, and other types of fluid, and the fluid is not particularly limited.

In the following description, an X direction in the figure is referred to as a right-and-left direction (a side toward which an arrow of the X direction is oriented is referred to as a left side, and the opposite side is referred to as a right side), a Y direction in the figure is referred to as a depth direction (a side toward which an arrow of the Y direction is oriented is referred to as a front side, and the opposite side is referred to as a back side), and a Z direction in the figure is referred to as an up-and-down direction (a side toward which an arrow of the Z direction is oriented is referred to as an upper side, and the opposite side is referred to as a lower side), in order to facilitate understanding of the description.

Of course, an orientation and the like of the fluid control apparatus 1 in use are not limited.

FIG. 1 is a perspective view of the fluid control apparatus 1 as viewed from diagonally above on the left.

FIG. 2 is a top view of the fluid control apparatus 1 as viewed from above.

FIG. 3 is a set of cross-sectional views along the line A-A illustrated in FIG. 2.

Note that an internal configuration of the fluid control apparatus 1 is indicated by a dashed line in FIG. 2. Further, an illustration of a drive mechanism 5 illustrated in FIG. 3 is omitted in FIGS. 1 and 2.

As illustrated in FIGS. 1 to 3, the fluid control apparatus 1 includes a flow-path space forming portion 2, an inflow opening 3, an outflow opening 4, and the drive mechanism 5.

The flow-path space forming portion 2 forms a flow path space S1 that is a flow path of fluid F.

Note that the space forming portion in the present disclosure includes a part that forms a space (a part that is in contact with a space), and a member that includes the part. It is assumed that, for example, a plurality of partition walls is connected to a single member to partition the member and this results in forming a plurality of spaces obtained by the partitioning. In this case, the single member to which the plurality of partition walls is connected serves as a space forming portion for each of the plurality of spaces.

In other words, the single member may be shared to be used as the space forming portion forming the plurality of spaces.

In the present embodiment, the flow-path space forming portion 2 has an approximate outer shape of a cylinder, and the flow path space S1 is formed inside of the flow-path space forming portion 2, as illustrated in FIGS. 1 to 3.

Specifically, the flow-path space forming portion 2 includes an upper surface member 6, a lower surface member 7, and spacer members 8a and 8b. An internal space that is surrounded by the upper surface member 6, the lower surface member 7, and the spacer members 8a and 8b is the flow path space S1.

It can also be said that the flow path space S1 is a pump room that generates pressure internally to exert a pump function on the fluid F.

The upper surface member 6 is a member in the form of a circular plate that has a circular outer shape, as viewed from the up-and-down direction (the Z direction). The upper surface member 6 includes a flexible member.

The lower surface member 7 is a member in the form of a circular plate that has a circular outer shape, as viewed from the up-and-down direction.

The lower surface member 7 has an outer shape that is identical to the outer shape of the upper surface member 6, as viewed from the up-and-down direction.

Further, the lower surface member 7 is arranged to face the upper surface member 6 in the up-and-down direction. Thus, the up-and-down direction (the Z direction) corresponds to a facing direction in which the upper surface member 6 and the lower surface member 7 face each other.

The spacer members 8a and 8b are arranged between the upper surface member 6 and the lower surface member 7.

As illustrated in FIG. 2, as viewed from the up-and-down direction, the spacer member 8a is arranged in a region included in a peripheral edge region 10a for semicircular portions of the upper surface member 6 and the lower surface member 7 and other than a region included in the peripheral edge region 10a and situated between a position P1 and a position P2, the semicircular portion being situated in back, the position P1 being on a diameter that extends in the X direction, the position P2 being obtained by the position P1 being offset backward.

Further, as viewed from the up-and-down direction, the spacer member 8b is arranged in a region included in a peripheral edge region 10b for semicircular portions of the upper surface member 6 and the lower surface member 7 and other than a region included in the peripheral edge region 10b and situated between the position P1 and a position P3, the semicircular portion being situated in front, the position P1 being on the diameter extending in the X direction, the position P3 being obtained by the position P1 being offset forward.

Thus, as viewed from the up-and-down direction, the spacer members 8a and 8b are arranged in the regions respectively included in the peripheral edge regions 10a and 10b and other than the region situated between the position P1 and a certain position (P2) and the region situated between the position P1 and another position (P3), the peripheral edge regions 10a and 10b corresponding to all of the periphery of a circular shape corresponding to the upper surface member 6 and the lower surface member 7, the position P1 being on the diameter extending in the X direction, the certain position being obtained by the position P1 being offset backward, the other position being obtained by the position P1 being offset forward.

The inflow opening 3 is an opening used to cause the fluid F to flow into the flow path space S1. As illustrated in FIG. 2, the inflow opening 3 is provided to an outer peripheral portion 11 of the flow path space S1, as viewed from the up-and-down direction. The inflow opening 3 is an opening through which a space external to the flow-path space forming portion 2 communicates with the flow path space S1.

In the present embodiment, a gap between a right end 12a of the spacer member 8a and a right end 13a of the spacer member 8b is formed as the inflow opening 3.

The outflow opening 4 is an opening used to cause the fluid F to flow out of the flow path space S1. As illustrated in FIG. 2, the outflow opening 4 is provided to a portion, in the outer peripheral portion 11 of the flow path space S1, that is different from a portion, in the outer peripheral portion 11 of the flow path space S1, that is provided with the inflow opening 3, as viewed from the up-and-down direction. Likewise, the outflow opening 4 is an opening through which the space external to the flow-path space forming portion 2 communicates with the flow path space S1.

In the present embodiment, a gap between a left end 12b of the spacer member 8a and a left end 13b of the spacer member 8b is formed as the outflow opening 4.

Thus, the inflow opening 3 and the outflow opening 4 are configured to face each other in the X direction.

Note that positions of the inflow opening 3 and the outflow opening 4, the number of inflow openings 3, the number of outflow openings 4, shapes of the inflow opening 3 and the outflow opening 4, and the like are not limited, and may be designed discretionarily. For example, a plurality of inflow openings 3 and a plurality of outflow openings 4 may be formed.

Further, as illustrated in FIG. 3, the upper surface member 6 is configured such that at least a portion of a region of the upper surface member 6 is curved toward the lower surface member 7 to have a concave shape in a reference state, the region of the upper surface member 6 being situated further inward than the outer peripheral portion 11 of the flow path space S1, as viewed from the up-and-down direction.

In other words, the upper surface member 6 is configured such that at least a portion of an inward region of the upper surface member 6 is curved toward the lower surface member 7 to have a concave shape, as viewed from the up-and-down direction.

Note that the reference state is a state in which the upper surface member 6 is not bent by the drive mechanism 5 described later. In other words, the reference state is a state in which an operation of bending the upper surface member 6 is not performed by the drive mechanism 5. It can also be said that the reference state is a state in which the fluid control apparatus 1 is not driven.

In the present disclosure, the state of having a concave shape includes, for example, a state in which a pressing force is applied to a certain point on the surface of a member and the member itself is deformed to have a concave shape. For example, the state of having a concave shape includes a state in which a plate member is deformed to have a concave shape by pressing being performed on a certain point on the plate member.

Further, the state of having a concave shape also includes a state in which a portion of a region on the surface of a member has a concave shape and is a hole portion. Moreover, the state of having a concave shape includes any states that can be referred to as a state of being curved toward a facing member to have a concave shape.

Further, the state in which the upper surface member 6 is curved toward the lower surface member 7 to have a concave shape, as illustrated in FIG. 3, can also be referred to as a state in which a facing distance of at least a portion of the inward region of the upper surface member 6 to the lower surface member 7 is smaller than a facing distance of an outer peripheral portion of the upper surface member 6 to the lower surface member 7.

For example, it is also conceivable that the facing distance could be reduced in a curved manner from the outer peripheral portion of the upper surface member 6 to a portion of the upper surface member 6 in which the facing distance is smallest (a portion that is situated most closely to the lower surface member 7), as in the case of the cross-sectional views illustrated in FIG. 3.

Further, it is also conceivable that only a portion of the inward region of the upper surface member 6 could be formed closely to the lower surface member 7.

The facing distance between the upper surface member 6 and the lower surface member 7 can also be referred to as a height of a flow path of the fluid F.

The state, in the present embodiment, in which the upper surface member 6 is curved toward the lower surface member 7 to have a concave shape can also be referred to as a state in which the flow path height in at least a portion of the inward region of the upper surface member 6 is smaller than the flow path height in the outer peripheral portion of the upper surface member 6.

In the present embodiment, the upper surface member 6 is configured such that a center portion 15 of the upper surface member 6 as viewed from the up-and-down direction is curved toward the lower surface member 7 to have a concave shape in the reference state. In other words, in the reference state, the upper surface member 6 that is a plate member has a shape obtained by the center portion 15 being deformed and curved toward the lower surface member 7 to have a concave shape.

Thus, the flow path space S1 is a space that has a shape of a cylinder of which an upper surface (a surface in contact with the upper surface member 6) is curved downward to have a concave shape in the reference state.

Note that a shape of the flow path space S1 serving as a pump room is not limited. For example, any shape such as a shape of a circle (including a perfect circle and an ellipse) or a polygonal shape as viewed from the up-and-down direction may be adopted. For example, when the upper surface member is curved toward the lower surface member to have a concave shape, this can provide an embodiment of the fluid control apparatus 1 according to the present technology.

As illustrated in FIG. 3, the drive mechanism 5 bends the upper surface member 6 to increase or decrease the volume of the flow path space S1.

In the present embodiment, the drive mechanism 5 is configured such that the upper surface member 6 being curved toward the lower surface member 7 to have a concave shape, is bent downward and upward. Further, the drive mechanism 5 is configured such that the upper surface member 6 is periodically bent downward and upward to cause the upper surface member 6 to oscillate in the up-and-down direction.

In the present embodiment, the upper surface member 6 is bent such that the center portion 15 corresponding to a concave portion of the upper surface member 6 (a portion in which the facing distance is smallest) in the reference state is moved by a largest distance in the up-and-down direction.

A of FIG. 3 illustrates the reference state in which the upper surface member 6 is not bent. The reference state can also be a state in which voltage is not applied to a piezoelectric element 17.

As illustrated in B of FIG. 3, the upper surface member 6 is bent downward. This results in a decrease in the volume of the flow path space S1. The volume becomes smallest when the center portion 15 of the upper surface member 6 is moved most downward (hereinafter referred to as a minimum volume state).

As illustrated in C of FIG. 3, the upper surface member 6 is bent upward from the reference state. This results in an increase in the volume of the flow path space S1. Then, the volume becomes largest when the center portion 15 of the upper surface member 6 is moved most upward (hereinafter referred to as a maximum volume state).

The upper surface member 6 is bent from the reference state illustrated in A of FIG. 3, and the maximum volume state and the minimum volume state are periodically caused repeatedly. This results in providing a pump function. Accordingly, the fluid F flowing into the flow path space S1 through the inflow opening 3 can flow out of the flow path space S1 through the outflow opening 4.

FIG. 4 schematically illustrates an example of a configuration of the drive mechanism 5.

In the present embodiment, the drive mechanism 5 includes the piezoelectric element 17 and a drive controller 18, as illustrated in FIG. 4.

The piezoelectric element 17 is connected to an upper surface 20 of the upper surface member 6 that is situated opposite to a lower surface 19 of the upper surface member 6 that faces the lower surface member 7. The piezoelectric element 17 is circular as viewed from the up-and-down direction, and is connected to a circular region of the upper surface member 6 that covers the flow path space S1.

The drive controller 18 applies voltage (an alternate-current (AC) voltage) in the form of a drive signal to the piezoelectric element 17 through, for example, wiring. A specific configuration of the drive controller 18 is not limited, and, for example, any circuit configuration may be adopted.

The piezoelectric element 17 is an element that enables electromechanical conversion. The piezoelectric element 17 enables the upper surface member 6 to be bent by expanding and contracting in response to voltage being applied.

The use of the piezoelectric element makes it possible to provide oscillation in a high frequency band with a high degree of ability to respond. In other words, it becomes possible to increase and decrease the volume of the flow path space S1 repeatedly at a very high speed, the increase and decrease causing a relatively small amount of variation in the volume of the flow path space S1. This results in being able to improve output (a pressure) of a pump, and thus to provide a high-level pump function.

In the present embodiment, a diaphragm 22 is implemented by the upper surface member 6 and the piezoelectric element 17.

Note that the configuration of the drive mechanism 5 is not limited to the configuration in which the piezoelectric element 17 is used. For example, a configuration in which, for example, a dielectric elastomer is used or a configuration in which solenoid is used may be adopted.

[Size]

The fluid control apparatus 1 of a diaphragm type is used in the present embodiment. This provides an advantage in, for example, making the fluid control apparatus 1 smaller.

For example, it is possible to provide the upper surface member 6 and the lower surface member 7 each having a size in which a diameter is about 10 mm and a thickness is about 1 mm. Further, designing can also be performed such that a reference facing distance between the upper surface member 6 and the lower surface member 7 is about 100 μm. Note that the reference facing distance corresponds to a facing distance before the upper surface member 6 is formed to have a concave shape, and can also be a facing distance in the outer peripheral portion 11 of the upper surface member 6.

Designing can be performed such that an amount of concave (an amount of deformation) of the upper surface member 6 is, for example, 10 μm to 80 μm. Note that the amount of concave is an amount of downward deformation of the center portion 15 from a state before the deformation, the center portion 15 being situated most closely to the lower surface member 7. In other words, it is possible to perform designing such that the center portion 15 situated most closely to the lower surface member 7 gets closer to the lower surface member 7 at a distance of 20 μm to 90 μm.

Of course, the size is not limited to being designed as described above, and the adoption of any size makes it possible to provide an embodiment of the fluid control apparatus 1 according to the present technology.

Note that it is desirable that the upper surface member 6 not be brought into contact with the lower surface member 7 in the minimum volume state illustrated in B of FIG. 3.

[Material]

In the present embodiment, a metallic material such as stainless or Alloy 42 is used for the upper surface member 6, the lower surface member 7, and the spacer members 8a and 8b. Of course, any other metallic material may be used. Further, any material, such as a plastic material, that is other than a metallic material may be used.

The upper surface member 6, the lower surface member 7, and the spacer members 8a and 8b may be made of different materials. Further, a portion of the upper surface member 6 that is connected to the spacer members 8a and 8b, and a portion of the upper surface member 6 that is in contact with the flow path space S1 may be made of different materials. In other words, a portion of the upper surface member 6 that is bent in order to increase and decrease the volume of the flow path space S1, and a portion of the upper surface member 6 that is connected to the spacer members 8a and 8b may be made of different materials.

For example, as viewed from the up-and-down direction, a region that corresponds to the outer peripheral portion of the upper surface member may be made of a metallic material, and the inward region of the upper surface member may be made of a plastic material.

[Production Method]

First, the upper surface member 6, the lower surface member 7, and the spacer members 8a and 8b, which are made of a metallic material, are created by any processing technology such as etching or laser processing.

The created upper surface member 6, lower surface member 7, and spacer members 8a and 8b are connected to each other to be stacked in the up-and-down direction.

In the present embodiment, the upper surface member 6, the lower surface member 7, and the spacer member 8a and 8 are stacked with a specified degree of accuracy in position and joined by diffused junction. This makes it possible to integrally form the flow-path space forming portion 2 made of metal.

This results in being advantageous in causing the diaphragm 22 (the upper surface member 6 and the piezoelectric element 17) to oscillate in a high frequency band with a high degree of ability to respond.

A specific method or configuration used to perform processing such as etching and diffused junction is not limited, and, for example, a well-known technology may be used.

Of course, the upper surface member 6, the lower surface member 7, and the spacer members 8a and 8b may be connected to each other by a method other than diffused junction.

Moreover, any other method such as die casting may be adopted in order to form the flow-path space forming portion 2.

FIG. 5 schematically illustrates an example of a method for connecting the piezoelectric element 17 to the upper surface member 6.

As illustrated in A of FIG. 5, the flow-path space forming portion 2 including the upper surface member 6 not having a concave shape (hereinafter referred to as the flow-path space forming portion 2 before being formed to have a concave shape) is placed on a holding fixture 23. The flow-path space forming portion 2 before being formed to have a concave shape is placed on the holding fixture 23 such that the lower surface member 7 is in contact with the holding fixture 23.

A specific configuration of the holding fixture 23 is not limited, and any fixture that can hold the flow-path space forming portion 2 before being formed to have a concave shape may be used.

A proper amount of adhesive is applied to the upper surface 20 of the upper surface member 6 before being formed to have a concave shape, and the piezoelectric element 17 is arranged at an appropriate position. For example, an epoxy adhesive or the like can be applied using a method such as dispenser or pad printing. Of course, the method is not limited thereto.

A pressure fixture 24 is arranged above the flow-path space forming portion 2 before being formed to have a concave shape.

The pressure fixture 24 is circular as viewed from the up-and-down direction, which is the same as the piezoelectric element 17. Then, a position of the pressure fixture 24 is determined such that pressure can be applied to an entire surface of the piezoelectric element 17.

An end portion 25 that is situated on a pressure applying surface of the pressure fixture 24 is made of a flexible material such as a silicon rubber.

As illustrated in B of FIG. 5, pressure is applied to the piezoelectric element 17 downward using the pressure fixture 24. Due to pressure being applied using the pressure fixture 24, the piezoelectric element 17 and the upper surface member 6 are deformed and curved toward the lower surface member 7 to have a concave shape. In this state, processing of hardening an adhesive is performed.

In the present embodiment, the end portion 25 of the pressure fixture 24 is made of a flexible material. Thus, the end portion 25 is deformed following the deformation of the piezoelectric element 17. This makes it possible to properly apply pressure to the entire surface of the piezoelectric element 17. Consequently, the piezoelectric element 17 can be bonded satisfactorily and deformed to have a desired concave shape.

Further, the end portion 25 is made of a flexible material. This also makes it possible to accommodate unevenness on the surface of the piezoelectric element 17, and thus to prevent the piezoelectric element 17 from, for example, being broken due to pressure being applied.

A condition for applying pressure using the pressure fixture 24 is not limited. A condition that enables the upper surface member 6 to be deformed to have a concave shape, may be set as appropriate. For example, a pressure-application force, a pressure-application time, a temperature, and the like may be set as appropriate such that an amount of concave of the upper surface member 6 is a desired amount of concave.

The present embodiment makes it possible to simultaneously bond the piezoelectric element 17 and deform the upper surface member 6 such that the upper surface member 6 has a concave shape, as illustrated in FIG. 5. In other words, when the piezoelectric element 17 is bonded, this enables the upper surface member 6 to be deformed to have a concave shape at the same time as the bonding of the piezoelectric element 17.

Thus, there is no need for, for example, a particular step or a particular fixture in order to form the upper surface member 6 such that the upper surface member 6 has a concave shape. This results in being able to simplify steps of producing the flow-path space forming portion 2, and thus to shorten the time necessary for the production.

Of course, the present technology is not limited to the method illustrated in FIG. 5. For example, the upper surface member 6 may be formed to have a concave shape in advance to be connected to the spacer members 8a and 8b. Further, the piezoelectric element 17 may be bonded to the upper surface member 6 formed to have a concave shape in advance.

[Decrease in Initial Volume]

FIG. 6 is a set of schematic diagrams used to describe an initial volume.

A of FIG. 6 schematically illustrates the flow path space S1 before the upper surface member 6 is formed to have a concave shape.

B of FIG. 6 schematically illustrates the flow path space S1 in the reference state.

C of FIG. 6 schematically illustrates the flow path space S1 during driving a pump.

As illustrated in A of FIG. 6, the upper surface member 6 and the lower surface member 7 are arranged at a reference facing distance H from each other.

As illustrated in B of FIG. 6, the upper surface member 6 is curved by an amount of concave Z to have a concave shape. The volume of the flow path space S1 in the reference state illustrated in B of FIG. 5 is assumed to be an initial volume.

It is assumed that the upper surface member 6 oscillates with an amplitude M by moving from the reference state in the up-and-down direction, as illustrated in C of FIG. 6. Further, it is assumed that a smallest facing distance between the upper surface member 6 and the lower surface member 7 in the minimum volume state is a minimum gap Gm.

A rate of volume variation that is represented by a formula indicated below can be used as an indicator used to evaluate a pump function of intaking the fluid F into the path space S1 and discharging the fluid F from the flow path space S1.

rate of volume variation=amount of volume variation/initial volume  (1)

The amount of volume variation is an amount of variation in the volume of the flow path space S1 that is caused due to the upper surface member 6 being bent, and can be represented by a difference between the minimum volume and the maximum volume of the flow path space S1. Thus, the amount of volume variation can also be represented by an amount of downward/upward deformation (an amount of downward/upward displacement) of the upper surface member 6.

The difference between the minimum volume and the maximum volume of the flow path space S1 is divided by the initial volume to calculate the rate of volume variation. A higher rate of volume variation results in providing a higher-level pump function, and this makes it possible to provide the fluid control apparatus 1 exhibiting a higher performance.

For example, when an amount of deformation of the upper surface member 6 remains unchanged, the rate of volume variation is higher if the initial volume is smaller. This results in providing a higher-level pump function. For example, the amount of deformation of the upper surface member 6 is greatly affected by the area of the piezoelectric element 17 connected to the upper surface member 6. Thus, it is important to decrease the initial volume when the area of the piezoelectric element 17 remains unchanged.

In the present embodiment, the upper surface member 6 is curved toward the lower surface member 7 to have a concave shape in the reference state, as illustrated in B of FIG. 6. Thus, the initial volume can be decreased. Therefore, the rate of volume variation can be made higher, as represented by the formula (1). This makes it possible to provide a high-level pump function.

For example, the initial volume can also be decreased by making the facing distance between the upper surface member 6 and the lower surface member 7 smaller in a state in which the upper surface member 6 does not have a concave shape, as illustrated in A of FIG. 6. However, in this case, the facing distance in the inflow opening 3 and the facing distance in the outflow opening 4 are made smaller in the same way, the inflow opening 3 and the outflow opening 4 being formed in the outer peripheral portion 11 of the flow path space S1. This results in reducing the cross-sectional areas of the inflow opening 3 and the outflow opening 4. Consequently, flow path resistances are increased at the inflow opening 3 and the outflow opening 4, and this results in making the level of the pump function lower.

In the present embodiment, the reference facing distance H is maintained in the outer peripheral portion 11 of the flow path space S1, as illustrated in B of FIG. 6. Thus, the initial volume is decreased in a state in which sufficient flow path heights are maintained at the inflow opening 3 and the outflow opening 4.

This makes it possible to prevent the flow path resistances from being increased at the inflow opening 3 and the outflow opening 4. This results in not blocking a flow of the fluid F, that is, this results in being able to sufficiently reduce a loss in flow path. Accordingly, a high-level pump function can be provided.

Further, when the upper surface member 6 does not have a concave shape, a reaction (a back pressure) to a force that is applied to the upper surface member 6 in the up-and-down direction greatly acts on the entirety of the upper surface member 6. This results in preventing high-speed oscillation (a piston motion), and thus in making the level of the pump function lower.

In the present embodiment, the center portion 15 of the upper surface member 6 is situated most closely to the lower surface member 7, as illustrated in B of FIG. 6, and the center portion 15 oscillates with a largest amplitude M. On the other hand, there is a small change in facing distance in the outer peripheral portion 11 of the flow path space S1, and a portion of the upper surface member 6 that corresponds to the outer peripheral portion 11 of the flow path space S1 oscillates with a small amplitude.

In other words, in the present embodiment, a very high pressure is generated in a center region of the upper surface member 6, whereas generation of pressure is suppressed in the outer peripheral portion 11 of the flow path space S1. This makes it possible to suppress a reaction that acts on the entirety of the upper surface member 6, and thus enables high-speed oscillation (a piston motion). This results in providing a high-level pump function.

For example, it is assumed that a fluid control apparatus is formed in a state in which the upper surface member 6 does not have a concave shape yet, as illustrated in A of FIG. 5. This is a comparative example. In this case, the amount of deformation of the upper surface member 6 remains unchanged. Thus, the amount of volume variation in the formula (1) remains unchanged.

As illustrated in B of FIG. 6, the upper surface member 6 is formed to have a concave shape, and then an initial area is reduced. For example, the initial volume is set to 60% of a volume before the upper surface member 6 is formed to have a concave shape. In this case, the rate of volume variation can be increased about 1.67-fold, which is calculated using the formula (1).

As described above, the pump function can be greatly improved by the upper surface member 6 being formed to have a concave shape.

Note that it is favorable that the upper surface member 6 not be brought into contact with the lower surface member 7 in the reference state illustrated in B of FIG. 6. Thus, it is favorable that “reference facing distance H>amount of concave Z”. Note that a value obtained by “reference facing distance H−amount of concave Z” corresponds to a minimum distance between the upper surface member 6 and the lower surface member 7 in the reference state.

Further, it is favorable that, upon driving the fluid control apparatus 1, the upper surface member 6 not be brought into contact with the lower surface member 7 in the minimum volume state.

Thus, it is favorable that “minimum gap Gm>0”, as illustrated in C of FIG. 5. Note that the minimum minimum gap Gm is represented by a formula indicated below.

minimum gap Gm=reference facing distance H−amount of concave Z−(amplitude M/2)  (2)

In other words, it is favorable that the minimum facing distance between the center portion 15 of the upper surface member 6 and the lower surface member 7 in the reference state illustrated in B of FIG. 5 be greater than ½ of the amplitude in the center portion 15 of the upper surface member 6 upon driving a pump.

Note that an optimal value of the amount of deformation of the upper surface member 6 differs depending on a relationship between flexural rigidity of the piezoelectric element 17, flexural rigidity of the upper surface member 6, and a force to apply pressure to the piezoelectric element 17 when the piezoelectric element 17 is bonded. Thus, it is also important to adjust a pressure-application force in consideration of flexural rigidity of each member.

In the present embodiment, the upper surface member 6 corresponds to an embodiment of a flexible portion having flexibility. Further, the lower surface member 7 corresponds to an embodiment of a facing portion that faces the flexible portion.

Furthermore, the upper surface member 6 also corresponds to an embodiment of a first plate member that is made of a metallic material and includes the flexible portion in a center region of the first plate member. In the present embodiment, an entire region including the center region is the flexible portion.

Further, the lower surface member 7 also corresponds to an embodiment of a second plate member that is made of a metallic material and includes the facing portion in a center region of the second plate member. In the present embodiment, an entire region including the center region is the facing portion.

The spacer members 8a and 8b correspond to an embodiment of a spacer member that has a specified thickness and includes an opening in a center region of the spacer member. The spacer member is arranged between the first plate member and the second plate member and joined to the first plate member and to the second plate member using diffused junction. The opening in the center region corresponds to a portion corresponding to the flow path space S1.

The flow-path space forming portion 2 includes the flow path space S1 between the flexible portion and the facing portion.

The drive mechanism 5 bends the flexible portion to increase and decrease the volume of the flow path space S1.

The inflow opening 3 illustrated in, for example, FIG. 2 may be used as an inlet used to intake the fluid F into the fluid control apparatus 1. Further, the outflow opening 4 may be used as an outlet used to discharge the fluid F from the fluid control apparatus 1.

Further, the inlet and the outlet may be respectively formed separately from the inflow opening 3 and the outflow opening 4. In this case, for example, an intake space forming portion that forms an intake space through which the inlet and the inflow opening 3 communicate with each other may be further formed. The intake space is a space used to lead, to the inflow opening 3, the fluid F intaken from the inlet. Further, a discharge space forming portion that forms a discharge space through which the outlet and the outflow opening 4 communicate with each other may be further formed. The discharge space is a space used to lead, to the outlet, fluid flowing out of the outflow opening 4.

A high-level pump function can also be provided in the flow path space S1 when the intake space and the discharge space described above are formed. This makes it possible to provide a small fluid control apparatus 1 exhibiting a high performance.

[Resonance Configuration]

The lower surface member 7 is formed as a flexible member. Further, the flow-path space forming portion 2 can also be configured such that the upper surface member 6 and the lower surface member 7 resonate with each other.

The amount of volume variation in the formula (1) can be increased by the upper surface member 6 and the lower surface member 7 resonating with each other. This makes it possible to improve the pump function.

A configuration in which the upper surface member 6 and the lower surface member 7 resonate with each other may be hereinafter referred to as a resonance configuration. Further, improving the pump function by the upper surface member 6 and the lower surface member 7 resonating with each other may be referred to as a resonance effect.

Note that the lower surface member 7 also serves as a diaphragm when the resonance configuration is adopted. A diaphragm implemented by the upper surface member 6 and the piezoelectric element 17 may be referred to as a first diaphragm, and a diaphragm implemented by the lower surface member 6 may be referred to as a second diaphragm.

Causing the upper surface member 6 and the lower surface member 7 to resonate with each other corresponds to causing the first diaphragm and the second diaphragm to resonate with each other.

For example, the configuration is made such that a resonance frequency (a primary resonance frequency) of the entirety of the upper surface member 6 and the piezoelectric element 17 is closer to a resonance frequency of the lower surface member 7. In other words, the configuration is made such that a resonance frequency of the first diaphragm is closer to a resonance frequency of the second diaphragm.

Consequently, oscillation of each of the first diaphragm and the second diaphragm is maximized at the resonance frequency. This makes it possible to generate a high pressure in a pump room.

Note that, due to resonance, the first diaphragm (the upper surface member 6 and the piezoelectric element 17) and the second diaphragm (the lower surface member 7) are respectively bent upward and downward in synchronization with each other. Further, due to resonance, the first diaphragm (the upper surface member 6 and the piezoelectric element 17) and the second diaphragm (the lower surface member 7) are respectively bent downward and upward in synchronization with each other.

In other words, in synchronization with each other, the two diaphragms are respectively bent in a direction in which the volume of the flow path space S1 is increased and in a direction in which the volume of the flow path space S1 is decreased. This results in providing an excellent resonance effect.

Note that the resonance frequency is defined by, for example, a specific gravity, the Young's modulus, a thickness, and a size of a material. When, for example, materials and sizes of the upper surface member 6, the piezoelectric element 17, and the lower surface member 7 are designed as appropriate, this makes it possible to cause the resonance frequencies of the first diaphragm and the second diaphragm to be closer to each other.

For example, the upper surface member 6 is formed using a metallic material such as stainless or Alloy 42. The lower surface member 7 is formed using the same metallic material as the upper surface member 6. Since the piezoelectric element 17 is bonded to the upper surface 20 of the upper surface member 6, a resonance frequency of the entirety of the first diaphragm is higher than a resonance frequency of the upper surface member 6 in a state in which the piezoelectric element 17 is not bonded to the upper surface member 6.

A thickness of the lower surface member 7 corresponding to the second diaphragm is made larger than a thickness of the upper surface member 6. This enables the resonance frequency of the entirety of the first diaphragm (the upper surface member 6 and the piezoelectric element 17) to be closer to the resonance frequency of the second diaphragm (the lower surface member 7). This makes it possible to provide a resonance configuration, and thus to provide a resonance effect.

When the resonance configuration is adopted, the upper surface member 6 corresponds to an embodiment of a first flexible portion. Further, the lower surface member 7 corresponds to an embodiment of a second flexible portion. The resonance configuration corresponds to a structure in which the first flexible portion and the second flexible portion resonate with each other.

For example, it is assumed that an adhesive or the like is used to connect the upper surface member 6, the spacer members 8a and 8b, and the lower surface member 7. In this case, a loss in transmitting oscillation energy, a deviation of a resonance frequency, and the like are easily caused. This results in difficulty in providing a resonance configuration.

As in the present embodiment, the upper surface member 6, the spacer members 8a and 8b, and the lower surface member 7 are joined by diffused junction to integrally form the flow-path space forming portion 2 made of metal. This makes it possible to suppress the loss in transmitting oscillation energy, the deviation of a resonance frequency, and the like, and thus to easily provide a resonance configuration.

Further, the adoption of a resonance configuration makes it possible to circulate oscillation energy generated in the first diaphragm between the first diaphragm and the second diaphragm, and thus to suppress a loss in the oscillation energy. This results in being able to provide a high-level pump function.

Of course, the present technology is not limited to being applied when the resonance configuration is adopted.

Products using fluid such as gas or liquid are used in various applications to, for example, industrial air cylinders, air bags, and cuffs used for blood pressure measurement. The use of fluid force of fluid makes it possible to provide new functions such as movement that is different from movement of actuators in the past, and generation of a sense of pressure or a tactile sense using pressure.

There is a need for a device that creates a flow of and a pressure of fluid, in order to use the fluid force. For example, pumps and blowers (fans) that have been used in the past have a relatively large size, and thus it is difficult to apply them to small devices and wearable devices.

The diaphragm-type pump using oscillation generated by the piezoelectric element is suitable to make an apparatus smaller, and can control pressure and a flow rate. For example, the diaphragm-type pump can be sufficiently applied as a pressure generation source of a cuff used in a portable sphygmomanometer.

It is desirable that a device including a pump function be made smaller in size and exhibit a higher performance, in order to use a fluid force in the future.

In the present embodiment, the upper surface member 6 arranged in a state in which the flow path space S1 is situated between the upper surface member 6 and the lower surface member 7 is curved toward the lower surface member 7 to have a concave shape in the reference state. Further, the inflow opening 3 and the outflow opening 4 are formed in the outer peripheral portion 11 of the flow path space S1. This makes it possible to provide a smaller fluid control apparatus 1 exhibiting a higher performance.

Further, the adoption of a resonance configuration makes it possible to achieve a much higher performance.

Second Embodiment

A fluid control apparatus according to a second embodiment of the present technology is described. In the following description, descriptions of a configuration and an operation similar to those of the fluid control apparatus 1 described in the embodiment above are omitted or simplified.

FIG. 7 is a top view of a fluid control apparatus 27 according to the second embodiment, as viewed from above.

FIG. 8 is a cross-sectional view along the line B-B illustrated in FIG. 7. The line B-B is a line that has a right angle bend in a center portion 37 of a first resonance plate 29.

FIG. 9 individually illustrates respective members that are included in the fluid control apparatus 27. Note that an illustration of the piezoelectric element is omitted in FIG. 9.

The fluid control apparatus 27 according to the present embodiment has an approximate outer shape of a quadrangular prism, and the flow path space S1, an intake space S2, and a discharge space S3 are formed inside of the fluid control apparatus 27.

The fluid control apparatus 27 includes a first fixation plate 28, the first resonance plate 29, a spacer member 30, a second resonance plate 31, and a second fixation plate 32. Further, the fluid control apparatus 27 includes a first piezoelectric element 33, a second piezoelectric element 34, and a check valve 35.

As illustrated in FIG. 8, the first fixation plate 28, the first resonance plate 29, the spacer member 30, the second resonance plate 31, and the second fixation plate 32 are plate members. Further, as illustrated in FIG. 9, the members respectively have approximate outer shapes of equal rectangles, as viewed from the up-and-down direction. In a state in which outer edges of the respective members are aligned, the members are stacked to be connected in the up-and-down direction.

As illustrated in FIG. 8, the respective members corresponding to the second fixation plate 32, the second resonance plate 31, the spacer member 30, the first resonance plate 29, and the first fixation plate 28 are stacked upward in this order.

As illustrated in FIG. 9, the spacer member 30 includes a center opening 38, two inlet openings 39a and 39b, and two outlet openings 40a and 40b.

The center opening 38 is formed in a center region of the spacer member 30, as viewed from the up-and-down direction. Further, the center opening 38 is circular, as viewed from the up-and-down direction. The center opening 38 is configured such that a center portion of the center opening 38 coincides with the center portion 37 of the first resonance plate 29.

The two inlet openings 39a and 39b are formed in a diagonal line that connects apexes 41a and 41c of the spacer member 30 in a state in which the center opening 38 is situated between the inlet openings 39a and 39b, the apex 41a being situated in back on the right, the apex 41c being situated in front on the left. Further, the two inlet openings 39a and 39b are formed to each communicate with an outer peripheral portion 38a of the center opening 38.

The inlet opening 39a is formed between the center opening 38 and the apex 41a to communicate with the center opening 38.

The inlet opening 39b is formed between the center opening 38 and the apex 41c to communicate with the center opening 38.

The two outlet openings 40a and 40b are formed in a diagonal line that connects apexes 41d and 41b of the spacer member 30 in a state in which the center opening 38 is situated between the outlet openings 40a and 40b, the apex 41d being situated in back on the left, the apex 41b being situated in front on the right. Further, the two outlet openings 40a and 40b are formed to each communicate with the outer peripheral portion 38a of the center opening 38.

The outlet opening 40a is formed between the center opening 38 and the apex 41d to communicate with the center opening 38.

The outlet opening 40b is formed between the center opening 38 and the apex 41b to communicate with the center opening 38.

As illustrated in FIG. 9, the two inlet openings 39a and 39b are formed symmetrically about a center portion of the spacer member 30 (a center portion of the center opening 38), as viewed from the up-and-down direction. The two outlet openings 40a and 40b are formed symmetrically about the center portion of the spacer member 30 (the center portion of the center opening 38), as viewed from the up-and-down direction.

Further, the two inlet openings 39a and 39b and the two outlet openings 40a and 40b have equal shapes, and are each formed to be open in a direction of the center portion of the spacer member 30.

The first resonance plate 29 includes a first flexible portion 42 that has flexibility, and two outlets 43a and 43b.

The first flexible portion 42 is formed in a center region of the first resonance plate 29, as viewed from the up-and-down direction. Further, the first flexible portion 42 is circular as viewed from the up-and-down direction.

The first flexible portion 42 is configured such that a center portion of the first flexible portion 42 coincides with the center portion 37 of the first resonance plate 29. In other words, it can also be said that the center portion 37 is the center portion 37 of the first flexible portion 42.

Further, the first flexible portion 42 is formed to cover the center opening 38 of the spacer member 30 from above (to overlap the center opening 38). Furthermore, the center portion 37 of the first flexible portion 42 and the center portion of the center opening 38 of the spacer member 30 coincide with each other.

As illustrated in FIG. 8, the first flexible portion 42 is configured such that at least a portion of a region of the first flexible portion 42 is curved toward the second resonance plate 31 to have a concave shape in the reference state, the region of the first flexible portion 42 being situated further inward than the outer peripheral portion 11 of the flow path space S1, as viewed from the up-and-down direction.

In the present embodiment, the first flexible portion 42 is configured such that the center portion 37 is curved toward the second resonance plate 31 to have a concave shape in the reference state, as viewed from the up-and-down direction.

The two outlets 43a and 43b are formed in a diagonal line that connects apexes 45d and 45b of the first resonance plate 29 in a state in which the first flexible portion 42 is situated between the outlets 43a and 43b, the apex 45d being situated in back on the left, the apex 45b being situated in front on the right.

The outlet 43a is formed between the first flexible portion 42 and the apex 45d. As illustrated in FIG. 7, the outlet 43a is formed in a portion that corresponds to a portion inside of the outlet opening 40a of the spacer member 30, as viewed from the up-and-down direction.

The outlet 43b is formed between the first flexible portion 42 and the apex 45b. The outlet 43b is formed in a portion that corresponds to a portion inside of the outlet opening 40b of the spacer member 30, as viewed from the up-and-down direction.

The first fixation plate 28 includes a center opening 46 and two outlet openings 47a and 47b.

The center opening 46 is formed in a center region of the first fixation plate 28, as viewed from the up-and-down direction. Further, the center opening 46 is circular as viewed from the up-and-down direction. The center opening 46 is configured such that a center portion of the center opening 46 coincides with the center portion of the center opening 38 of the spacer member 30.

The two outlet openings 47a and 47b are formed in a diagonal line that connects apexes 48d and 48b of the first fixation plate 28 in a state in which the center opening 46 is situated between the outlet openings 47a and 47b, the apex 48d being situated in back on the left, the apex 48b being situated in front on the right.

The outlet opening 47a is formed between the center opening 46 and the apex 48d. The outlet opening 47a has a shape obtained by a rectangular opening and a semicircular opening communicating with each other. The outlet opening 47a is formed such that a portion corresponding to the rectangular opening is situated along the center opening 46 and such that a top of a portion corresponding to the semicircular opening is oriented toward the apex 48d.

The outlet opening 47b is formed between the center opening 46 and the apex 48db. The outlet opening 47b has a shape equal to the shape of the outlet opening 47a. The outlet opening 47b is formed such that a portion corresponding to the rectangular opening is situated along the center opening 46 and such that a top of a portion corresponding to the semicircular opening is oriented toward the apex 48b.

Further, as illustrated in FIG. 7, the outlet opening 47a is formed such that the outlet 43a of the first resonance plate 29 is situated inside of the outlet opening 47a, as viewed from the up-and-down direction. The outlet opening 47b is formed such that the outlet 43b of the first resonance plate 29 is situated inside of the outlet opening 47b, as viewed from the up-and-down direction.

Thus, the outlet opening 40a of the spacer member 30 and the outlet opening 47a of the first fixation plate 28 are formed to overlap each other, as viewed from the up-and-down direction. Further, the outlet opening 40b of the spacer member 30 and the outlet opening 47b of the first fixation plate 28 are formed to overlap each other.

The second resonance plate 31 includes a second flexible portion 49 that has flexibility, and two inlets 50a and 50b.

The second flexible portion 49 is formed in a center region of the second resonance plate 31, as viewed from the up-and-down direction. Further, the second flexible portion 49 is circular as viewed from the up-and-down direction.

The second flexible portion 49 is configured such that a center portion of the second flexible portion 49 coincides with a center portion 51 of the second resonance plate 29. In other words, it can also be said that the center portion 51 is the center portion 51 of the second flexible portion 49.

Further, the second flexible portion 49 is formed to cover the center opening 38 of the spacer member 30 from below (to overlap the center opening 38). Furthermore, the center portion 51 of the second flexible portion 49 and the center portion of the center opening 38 of the spacer member 30 coincide with each other.

As illustrated in FIG. 8, the second flexible portion 49 is configured such that at least a portion of a region of the second flexible portion 49 is curved toward the first resonance plate 29 to have a concave shape in the reference state, the region of the second flexible portion 49 being situated further inward than the outer peripheral portion 11 of the flow path space S1, as viewed from the up-and-down direction.

In the present embodiment, the second flexible portion 49 is configured such that the center portion 51 is curved toward the first resonance plate 29 to have a concave shape in the reference state, as viewed from the up-and-down direction.

In the present embodiment, the first flexible portion 42 of the first resonance plate 29 and the second flexible portion 49 of the second resonance plate 31 face each other in the up-and-down direction in a state in which the center opening 38 of the spacer member 30 is situated between the first flexible portion 42 and the second flexible portion 49, as illustrated in FIG. 8.

The first flexible portion 42 is configured such that the center portion 37 is curved toward the second flexible portion 49 to have a concave shape in the reference state. The second flexible portion 49 is configured such that the center portion 51 is curved toward the first flexible portion 42 to have a concave shape in the reference state.

The two inlets 50a and 50b are formed in a diagonal line that connects apexes 52a and 52c of the second resonance plate 31 in a state in which the second flexible portion 49 is situated between the inlets 50a and 50b, the apex 52a being situated in back on the right, the apex 52c being situated in front on the left.

The inlet 50a is formed between the second flexible portion 49 and the apex 52a. As illustrated in FIG. 7, the inlet 50a is formed in a portion that corresponds to a portion inside of the inlet opening 39a of the spacer member 30, as viewed from the up-and-down direction.

The inlet 50b is formed between the second flexible portion 49 and the apex 52c. The inlet 50b is formed in a portion that corresponds to a portion inside of the inlet opening 39b of the spacer member 30, as viewed from the up-and-down direction.

The second fixation plate 32 includes a center opening 53 and two inlet openings 54a and 54b.

The center opening 53 is formed in a center region of the second fixation plate 32, as viewed from the up-and-down direction. Further, the center opening 53 is circular as viewed from the up-and-down direction. The center opening 53 is configured such that a center portion of the center opening 53 coincides with the center portion of the center opening 38 of the spacer member 30.

The two inlet openings 54a and 54b are formed in a diagonal line that connects apexes 55a and 55c of the second fixation plate 32 in a state in which the center opening 53 is situated between the inlet openings 54a and 54b, the apex 55a being situated in back on the right, the apex 55c being situated in front on the left.

The inlet openings 54a is formed between the center opening 53 and the apex 55a. The inlet opening 54a has a shape equal to the shape of the outlet opening 47a formed in the first fixation plate 28. The inlet opening 54a is formed such that a portion corresponding to the rectangular opening is situated along the center opening 53 and such that a top of a portion corresponding to the semicircular opening is oriented toward the apex 55a.

The inlet opening 54b is formed between the center opening 53 and the apex 55c. The inlet opening 54b has a shape equal to the shape of the inlet opening 54a. The inlet opening 54b is formed such that a portion corresponding to the rectangular opening is situated along the center opening 53 and such that a top of a portion corresponding to the semicircular opening is oriented toward the apex 55c.

Further, as illustrated in FIG. 7, the inlet opening 54a is formed such that the inlet 50a of the second resonance plate 31 is situated inside of the inlet opening 54a, as viewed from the up-and-down direction. The inlet opening 54b is formed such that the inlet 50b of the second resonance plate 31 is situated inside of the inlet opening 54b, as viewed from the up-and-down direction.

Thus, the inlet opening 39a of the spacer member 30 and the inlet opening 54a of the second fixation plate 32 are formed to overlap each other, as viewed from the up-and-down direction. Further, the inlet opening 39b of the spacer member 30 and the inlet opening 54b of the second fixation plate 32 are formed to overlap each other.

As illustrated in FIG. 9, the first fixation plate 28 will have the same configuration as the second fixation plate 32 when the first fixation plate 28 is rotated 90 degrees, as viewed from the up-and-down direction. In other words, the first fixation plate 28 and the second fixation plate 32 have the same configuration with respect to an arrangement relationship of the openings, as viewed from the up-and-down direction. Thus, two identical members are provided to have different orientations. Accordingly, the two members can be respectively used as the first fixation plate 28 and the second fixation plate 32.

Likewise, the first resonance plate 29 and the second resonance plate 31 have the same configuration with respect to a positional relationship of the flexible portion (the first flexible portion 42/the second flexible portion 49) formed in the center region of the resonance plate and the two openings (the inlets 50a and 50b/the outlets 43a and 43b). Thus, two identical members are provided to have different orientations. Accordingly, the two members are respectively used as the first resonance plate 29 and the second resonance plate 31.

Identical members can be used by being provided to have different orientations, as described above. This makes it possible to reduce costs to produce parts.

As illustrated in FIG. 8, the first fixation plate 28, the first resonance plate 29, the spacer member 30, the second resonance plate 31, and the second fixation plate 32 are stacked to be connected in the up-and-down direction.

The center opening 38 of the spacer member 30 is situated between the first flexible portion 42 of the first resonance plate 29 and the second flexible portion 42 of the second resonance plate 31 to form the flow path space S1.

A communication opening through which the center opening 38 illustrated in FIG. 9 communicates with the two inlet openings 39a and 39b illustrated in FIG. 9 is formed as the inflow opening 3 illustrated in FIG. 1. Further, a communication opening through which the center opening 38 communicates with the two outlet openings 40a and 40b is formed as the outflow opening 4 illustrated in FIG. 1.

Thus, in the present embodiment, the first resonance plate 29, the second resonance plate 31, and the spacer member 30 serve as a flow-path space forming portion.

As illustrated in FIG. 8, the two inlet openings 39a and 39b of the spacer member 30 are situated between the first resonance plate 29 and the second resonance plate 31 to form the intake space S2.

The inlets 50a and 50b are formed in a region, in the second resonance plate 31, that covers the two inlet openings 39a and 39b of the spacer member 30. The inlets 50a and 50b enable the intake space S2 to communicate with the two inlet openings 54a and 54b of the second fixation plate 32.

In the present embodiment, the first resonance plate 29, the second resonance plate 31, and the spacer member 30 also serve as an intake space forming portion that forms the intake space S2 through which the inflow opening 3 communicates with the inlets 50a and 50b.

As illustrated in FIG. 8, the two outlet openings 40a and 40b of the spacer member 30 are situated between the first resonance plate 29 and the second resonance plate 31 to form the discharge space S3.

The outlets 43a and 43b are formed in a region, in the first resonance plate 29, that covers the two outlet openings 40a and 40b of the spacer member 30. The outlets 43a and 43b enable the discharge space S3 to communicate with the two outlet openings 47a and 47b of the first fixation plate 28.

In the present embodiment, the first resonance plate 29, the second resonance plate 31, and the spacer member 30 also serve as a discharge space forming portion that forms the discharge space S3 through which the outflow opening 4 communicates with the outlets 43a and 43b.

The fluid F is intaken into the intake space S2 through the two inlet openings 54a and 54b of the second fixation plate 32 passing through the inlets 50a and 50b. Through the inflow opening 3, the intaken fluid F flows into the flow path space S1 serving as a pump room.

The pump function causes the fluid F flowing into the flow path space S1 to flow out of the flow path space S1 through the outflow opening 4, and to flow into the discharge space S3. The fluid F is discharged from the discharge space S3 through the two outlet openings 47a and 47b of the first fixation plate 28 passing through the outlets 43a and 43b.

As illustrated in FIG. 8, the first piezoelectric element 33 is connected to an upper surface 57 of the first flexible portion 42. The upper surface 57 of the first flexible portion 42 is a surface that is opposite to a surface of the first flexible portion 42 that faces the second flexible portion 49. The first piezoelectric element 33 is arranged within the center opening 46 of the first fixation plate 28.

As illustrated in FIG. 7, the first piezoelectric element 33 is circular as viewed from the up-and-down direction. The first piezoelectric element 33 is connected to the upper surface 57 of the first flexible portion 42 such that a center portion of the first piezoelectric element 33 coincides with the center portion 37 of the first flexible portion 42.

Further, the first piezoelectric element 33 is slightly smaller in size than the upper surface 57 of the first flexible portion 42, as viewed from the up-and-down direction. In other words, the first piezoelectric element 33 is arranged in a region that is slightly smaller than an entire region of an upper surface of the flow path space S1, as viewed from the up-and-down direction.

As illustrated in FIG. 8, the second piezoelectric element 34 is connected to a lower surface 58 of the second flexible portion 49. The lower surface 58 of the second flexible portion 49 is a surface that is opposite to a surface of the second flexible portion 49 that faces the first flexible portion 42. The second piezoelectric element 34 is arranged within the center opening 53 of the second fixation plate 32.

The second piezoelectric element 34 is circular as viewed from the up-and-down direction, where the shape of the second piezoelectric element 34 is equal to the shape of the first piezoelectric element 33. Further, the second piezoelectric element 34 is arranged to overlap the first piezoelectric element 33, as viewed from the up-and-down direction.

Thus, the second piezoelectric element 34 is connected to the lower surface 58 of the second flexible portion 49 such that a center portion of the second piezoelectric element 34 coincides with the center portion 51 of the second flexible portion 49.

Further, the second piezoelectric element 34 is slightly smaller in size than the lower surface 58 of the second flexible portion 49, as viewed from the up-and-down direction. In other words, the second piezoelectric element 34 is arranged in a region that is slightly smaller than an entire region of a lower surface of the flow path space S1, as viewed from the up-and-down direction.

In the present embodiment, the first diaphragm is implemented by the first flexible portion 42 of the first resonance plate 29 and the first piezoelectric element 33. The second diaphragm is implemented by the second flexible portion 49 of the second resonance plate 31 and the second piezoelectric element 34.

As illustrated in FIG. 8, the check valve 35 is provided to each of the two outlets 43a and 44b. The check valve 35 permits the fluid F discharged from the outlets 43a and 44b to flow into the outlet openings 47a and 47b. On the other hand, the check valve 35 prevents the fluid F from flowing into the outlets 43a and 44b through the outlet openings 47a and 47b.

When the check valve 35 is provided to each of the outlets 43a and 44b, this makes it possible to prevent the fluid F from flowing backward, and thus to provide a high-level pump function.

A specific configuration of the check valve 35 is not limited, and any configuration may be adopted. Note that an illustration of the check valve 35 is omitted in FIG. 7.

Note that, in the present embodiment, the application of drive signals (alternate-current (AC) voltage) to the first piezoelectric element 33 and the second piezoelectric element 34 makes it possible to cause the first diaphragm and the second diaphragm to oscillate in a high frequency band with a high degree of ability to respond. In other words, the volume of the flow path space S1 is increased and decreased repeatedly (a pumping operation) at a very high speed.

Consequently, the level of the pump function is not decreased and a high performance is maintained if no check valves are provided to the inlets 50a and 50b. This makes it possible to reduce the number of check values necessary, and thus to reduce costs for parts.

Of course, a check valve may be provided to each of the inlets 50a and 50b.

In the present embodiment, the first resonance plate 29 corresponds to an embodiment of a first plate member. The second resonance plate 31 corresponds to an embodiment of a second plate member. It can also be said that the first resonance plate 29 corresponds to an embodiment of the second plate member, and the second resonance plate 31 corresponds to an embodiment of the first plate member.

The spacer member 30 corresponds to an embodiment of a spacer member.

The first piezoelectric element 33 and the second piezoelectric element respectively serve as drive mechanisms that respectively bend the first flexible portion 42 and the second flexible portion 49. The drive controllers (not illustrated) also serving as the drive mechanisms respectively apply drive signals (alternate-current (AC) voltages) to the first piezoelectric element 33 and the second piezoelectric element 34.

[Material]

In the present embodiment, a metallic material such as stainless or Alloy 42 is used for the first fixation plate 28, the first resonance plate 29, the spacer member 30, the second resonance plate 31, and the second fixation plate 32. Of course, any other metallic material may be used. Further, any material, such as a plastic material, that is other than a metallic material may be used.

For example, the first flexible portion 42 of the first resonance plate 29 may be made of, for example, a plastic material, and a portion of the first resonance plate 29 that is connected to the spacer member 30 and the first fixation plate 28 may be made of a metallic material.

Likewise, the second flexible portion 49 of the second resonance plate 31 may be made of, for example, a plastic material, and a portion of the second resonance plate 31 that is connected to the spacer member 30 and the second fixation plate 32 may be made of a metallic material.

[Resonance Configuration]

A resonance configuration in which the first diaphragm (the first flexible portion 42 and the first piezoelectric element 33) and the second diaphragm (the second flexible portion 49 and the second piezoelectric element 34) resonate with each other is adopted in the present embodiment. In other words, the first flexible portion 42 and the second flexible portion 49 are configured to resonate with each other.

Specifically, the configuration is made such that a resonance frequency of the entirety of the first flexible portion 42 and the first piezoelectric element 33 is closer to a resonance frequency of the entirety of the second flexible portion 49 and the second piezoelectric element 34.

[Production Method]

FIGS. 10 and 11 are sets of schematic diagrams used to describe a method for producing the fluid control apparatus 27.

First, the first fixation plate 28, the first resonance plate 29, the spacer member 30, the second resonance plate 31, and the second fixation plate 32, which are made of a metallic material, are created by any processing technology such as etching or laser processing.

As illustrated in A and B of FIG. 10, the created first fixation plate 28, first resonance plate 29, spacer member 30, second resonance plate 31, and second fixation plate 32 are stacked to be connected to each other with a specified degree of accuracy in position.

In the present embodiment, the respective members are joined by diffused junction. Of course, any other methods may be used.

As illustrated in C of FIG. 10, the first piezoelectric element 33 is connected to the upper surface 57 of the first flexible portion 42 through an adhesive 60. Further, the second piezoelectric element 34 is connected to the lower surface 58 of the second flexible portion 49 through an adhesive 61.

As illustrated in D of FIG. 10, the first flexible portion 42 is curved toward the second flexible portion 49 to have a concave shape. Further, the second flexible portion 49 is curved toward the first flexible portion 42 to have a concave shape.

As illustrated in D of FIG. 10, the check valve 35 is provided to each of the two outlets 43a and 44b.

FIG. 11 schematically illustrates an example of a method for connecting the first piezoelectric element 33 to the first flexible portion 42 and connecting and the second piezoelectric element 34 to the second flexible portion 49.

As illustrated in A of FIG. 11, the fluid control apparatus 27 before being formed to have a concave shape, which is illustrated in B of FIG. 10, is placed on the holding fixture 23. First, the fluid control apparatus 27 before being formed to have a concave shape is placed on the holding fixture 23 such that the second fixation plate 32 is in contact with the holding fixture 23.

Further, as illustrated in A of FIG. 11, pressure is applied to the first piezoelectric element 33 downward using the pressure fixture 24. Due to pressure being applied using the pressure fixture 24, the first piezoelectric element 33 and the first flexible portion 42 are deformed and curved toward the second flexible portion 49 to have a concave shape. In this state, processing of hardening the adhesive 60 is performed.

Accordingly, the fluid control apparatus 27 including the first diaphragm (the first flexible portion 42 and the first piezoelectric element 33) formed to have a concave shape is created, as illustrated in B of FIG. 11.

Note that the end portion 25 of the pressure fixture 24 is made of a flexible material such as a silicon rubber.

As illustrated in C of FIG. 11, the fluid control apparatus 27 is turned upside down, and is placed on the holding fixture 23 such that the first fixation plate 28 is in contact with the holding fixture 23.

Then, as illustrated in C of FIG. 11, pressure is applied to the second piezoelectric element 34 downward using the pressure fixture 24. Due to pressure being applied using the pressure fixture 24, the second piezoelectric element 34 and the second flexible portion 49 are deformed and curved toward the first flexible portion 42 to have a concave shape. In this state, processing of hardening the adhesive 61 is performed.

Accordingly, the fluid control apparatus 27 including the second diaphragm (the second flexible portion 49 and the second piezoelectric element 34) formed to have a concave shape is created, as illustrated in D of FIG. 11.

A condition for applying pressure when the first piezoelectric element 33 is bonded (hereinafter referred to as a first condition for applying pressure) and a condition for applying pressure when the second piezoelectric element 34 is bonded (hereinafter referred to as a second condition for applying pressure) may each be set discretionarily. For example, a pressure-application force, a pressure-application time, a temperature, and the like may be set as appropriate such that each of an amount of concave of the first flexible portion 42 and an amount of concave of the second flexible portion 49 is a desired amount of concave.

For example, the first condition for applying pressure and the second condition for applying pressure are made equal. This makes it possible to simplify production steps. Further, this makes it possible to make an amount of concave of the first flexible portion 42 and an amount of concave of the second flexible portion 49 equal.

As described above, a resonance frequency of a member is also affected by a shape of the member. Thus, making the first condition for applying pressure and the second condition for applying pressure equal results in being advantageous in enabling the resonance frequency of the first diaphragm (the first flexible portion 42 and the first piezoelectric element 33) to be closer to the resonance frequency of the second diaphragm (the second flexible portion 49 and the second piezoelectric element 34).

Of course, the first condition for applying pressure and the second condition for applying pressure may be set to be different from each other. For example, the amount of concave of the first flexible portion 42 and the amount of concave of the second flexible portion 49 may be different from each other.

As illustrated in FIG. 11, the present embodiment makes it possible to simultaneously bond the first piezoelectric element 33 and deform the first flexible portion 42 such that the first flexible portion 42 has a concave shape. In other words, when the first piezoelectric element 33 is bonded, this enables the first flexible portion 42 to be deformed to have a concave shape at the same time as the bonding of the first piezoelectric element 33.

Further, the present embodiment makes it possible to simultaneously bond the second piezoelectric element 34 and deform the second flexible portion 49 such that the second flexible portion 49 has a concave shape. In other words, when the second piezoelectric element 34 is bonded, this enables the second flexible portion 49 to be deformed to have a concave shape at the same time as the bonding of the second piezoelectric element 34.

This results in being able to simplify steps of producing the fluid control apparatus 27, and thus to shorten the time necessary for the production.

[Pumping Operation]

In the present embodiment, the drive controllers (not illustrated) respectively apply identical drive signals (alternate-current (AC) voltages) to the first piezoelectric element 33 and the second piezoelectric element 34.

Consequently, the first diaphragm (the first flexible portion 42 and the first piezoelectric element 33) and the second diaphragm (the second flexible portion 49 and the second piezoelectric element 34) can be respectively bent upward and downward in synchronization with each other.

Further, the first diaphragm (the first flexible portion 42 and the first piezoelectric element 33) and the second diaphragm (the second flexible portion 49 and the second piezoelectric element 34) can be respectively bent downward and upward in synchronization with each other.

In other words, in synchronization with each other, the two diaphragms are respectively bent in a direction in which the volume of the flow path space S1 is increased and in a direction in which the volume of the flow path space S1 is decreased. This results in being able to provide a very high-level pump function.

Further, in the present embodiment, a resonance configuration in which the first diaphragm and the second diaphragm resonate with each other is adopted. Thus, oscillation of each of the first diaphragm and the second diaphragm is maximized at the resonance frequency. This makes it possible to provide a very high-level pump function.

FIG. 12 schematically illustrates an example of a flow of the fluid F upon a pumping operation.

In the present embodiment, the fluid F intaken from the inlet 50a situated in back on the right passes through the flow path space S1 to be discharged from the outlet 43b situated in front on the right.

Further, the fluid F intaken from the inlet 50b situated in front on the left passes through the flow path space S1 to be discharged from the outlet 43a situated in back on the left.

Of course, flow path designing is not limited thereto.

Note that inlets may be respectively formed in regions of the first resonance plate 29 that respectively cover the two inlet openings 39a and 39b of the spacer member 30. Further, outlets may be respectively formed in regions of the second resonance plate 31 that respectively cover the two outlet openings 40a and 40b of the spacer member 30.

[Decrease in Initial Volume]

FIG. 13 is a set of schematic diagrams used to describe an initial volume, and FIG. 14 is a set of tables used to describe the initial volume.

A of FIG. 13 schematically illustrates the flow path space S1 before the first flexible portion 42 and the second flexible portion 49 are formed to have a concave shape.

B of FIG. 13 schematically illustrates the flow path space S1 in the reference state.

C of FIG. 13 schematically illustrates the flow path space S1 during driving a pump.

As illustrated in A of FIG. 13, the first flexible portion 42 and the second flexible portion 49 are arranged at the reference facing distance H from each other.

As illustrated in B of FIG. 13, the first flexible portion 42 is curved by an amount of concave Z1 to have a concave shape. Further, the second flexible portion 49 is curved by an amount of concave Z2 to have a concave shape.

It is assumed that the first flexible portion 42 oscillates with an amplitude M1 by moving from the reference state in the up-and-down direction, as illustrated in C of FIG. 13. Further, it is assumed that the second flexible portion 49 oscillates with an amplitude M2 in synchronization with the first flexible portion 42.

It is assumed that a smallest facing distance between the first flexible portion 42 and the second flexible portion 49 in the minimum volume state is a minimum gap Gm.

In the present embodiment, the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape in the reference state, as illustrated in B of FIG. 13. Thus, the initial volume can be decreased. Therefore, the rate of volume variation can be made higher, as represented by the formula (1). This makes it possible to provide a high-level pump function.

Further, the reference facing distance H is maintained in the outer peripheral portion 11 of the flow path space S1. This makes it possible to prevent the flow path resistances from being increased at the inflow opening 3 and the outflow opening 4. This results in not blocking a flow of the fluid F, that is, this results in being able to sufficiently reduce a loss in flow path. Accordingly, a high-level pump function can be provided.

Further, this makes it possible to suppress a reaction (a back pressure) that acts on each of the first flexible portion 42 and the second flexible portion 49, and thus enables high-speed oscillation (a piston motion). This results in providing a high-level pump function.

For example, the first flexible portion 42 and the second flexible portion 49 are each formed to have a size of a diameter of 9 mm. Further, two embodiments that are an embodiment in which the reference facing distance H is 0.1 mm and an embodiment in which the reference facing distance H is 0.2 mm, are provided.

Further, the first flexible portion 42 and the second flexible portion 49 are designed such that the amount of concave Z1 of the first flexible portion 42 and the amount of concave Z2 of the second flexible portion 49 are equal.

In this case, the initial volume and the amount of concave have a relationship given in the tables of FIG. 14.

In the case in which the reference facing distance H is 0.1 mm, the initial volume is 6.361725 cubic millimeters when the amounts of concave Z1 and Z2 are both zero (that is, before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape).

The initial volume is 5.725552 cubic millimeters when the amounts of concave Z1 and Z2 are both 0.01 mm. Thus, the initial volume can be decreased to 90% of the initial volume before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape. This makes it possible to increase the rate of volume variation about 1.11-fold, which is calculated using the formula (1).

The initial volume is 5.089372 cubic millimeters when the amounts of concave Z1 and Z2 are both 0.02 mm. Thus, the initial volume can be decreased to 80% of the initial volume before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape. This makes it possible to increase the rate of volume variation about 1.25-fold, which is calculated using the formula (1).

The initial volume is 3.816968 cubic millimeters when the amounts of concave Z1 and Z2 are both 0.04 mm. Thus, the initial volume can be decreased to 60% of the initial volume before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape. This makes it possible to increase the rate of volume variation about 1.67-fold, which is calculated using the formula (1).

In the case in which the reference facing distance H is 0.2 mm, the initial volume is 12.72345 cubic millimeters when the amounts of concave Z1 and Z2 are both zero (that is, before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape).

The initial volume is 12.08728 cubic millimeters when the amounts of concave Z1 and Z2 are both 0.01 mm. Thus, the initial volume can be decreased to 95% of the initial volume before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape. This makes it possible to increase the rate of volume variation about 1.05-fold, which is calculated using the formula (1).

The initial volume is 11.4511 cubic millimeters when the amounts of concave Z1 and Z2 are both 0.02 mm. Thus, the initial volume can be decreased to 90% of the initial volume before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape. This makes it possible to increase the rate of volume variation about 1.11-fold, which is calculated using the formula (1).

The initial volume is 10.17869 cubic millimeters when the amounts of concave Z1 and Z2 are both 0.04 mm. Thus, the initial volume can be decreased to 80% of the initial volume before the first flexible portion 42 and the second flexible portion 49 are each formed to have a concave shape. This makes it possible to increase the rate of volume variation about 1.25-fold, which is calculated using the formula (1).

Note that it is favorable that the first flexible portion 42 not be brought into contact with the second flexible portion 49 in the reference state illustrated in B of FIG. 13. Thus, it is favorable that “reference facing distance H>amount of concave Z1+amount of concave Z2”. Note that a value obtained by “reference facing distance H−(amount of concave Z1+amount of concave Z2)” corresponds to a minimum facing distance between the first flexible portion 42 and the second flexible portion 49 in the reference state.

Further, it is favorable that, upon driving the fluid control apparatus 1, the first flexible portion 42 not be brought into contact with the second flexible portion 49 in the minimum volume state.

Thus, it is favorable that “minimum gap Gm>0”, as illustrated in C of FIG. 13. Note that the minimum minimum gap Gm is represented by a formula indicated below.

minimum gap Gm=reference facing distance H−(amount of concave Z1+amount of concave Z2)−(amplitude M1/2+amplitude M2/2)  (3)

In other words, it is favorable that the minimum facing distance between the center portion 15 of the upper surface member 6 and the center portion 51 of the lower surface member 7 in the reference state illustrated in B of FIG. 13 be greater than “amplitude M1/2+amplitude M2/2” upon driving a pump.

Note that an optimal value of the amount of deformation of the first flexible portion 42 differs depending on a relationship between flexural rigidity of the first piezoelectric element 33, flexural rigidity of the first flexible portion 42, and a force to apply pressure to the first piezoelectric element 33 when the first piezoelectric element 33 is bonded. An optimal value of the amount of deformation of the second flexible portion 49 differs depending on a relationship between flexural rigidity of the second piezoelectric element 34, flexural rigidity of the second flexible portion 49, and a force to apply pressure to the second piezoelectric element 34 when the second piezoelectric element 34 is bonded. Thus, it is also important to adjust a pressure-application force in consideration of flexural rigidity of each member.

The configuration of the fluid control apparatus 27 according to the present embodiment is adopted, and the first flexible portion 42 and the second flexible portion 49 are each formed to have a diameter of 13 mm. Further, the reference facing distance H is set to 1 mm.

An alternate-current (AC) voltage of 30 Vpp is applied to each of the first piezoelectric element 33 and the second piezoelectric element 34 to drive the fluid control apparatus 27.

This results in obtaining output having a maximum flow rate of 800 ml/min or more, and a maximum pressure of 30 kPa or more. As described above, a small fluid control apparatus 27 exhibiting a very high performance can be obtained.

Third Embodiment

FIG. 15 schematically illustrates examples of a configuration of a fluid control apparatus according to a third embodiment.

A fluid control apparatus 64 of the present embodiment is different from the fluid control apparatus 27 according to the second embodiment in that the second piezoelectric element 34 is not provided.

In other words, a piezoelectric element (the first piezoelectric element 33) is connected only to the first flexible portion 42 in the present embodiment. Further, due to oscillation of the first flexible portion 42, the first flexible portion 42 and a second flexible portion oscillate with each other.

It can also be said that the fluid control apparatus 64 according to the present embodiment has a configuration obtained by combining the fluid control apparatus 1 according to the first embodiment and the fluid control apparatus 27 according to the second embodiment.

As illustrated in A of FIG. 15, a second resonance plate 65 may be used in the form of a flat plate, without being deformed to have a concave shape. Thus, a second flexible portion 66 is in the form of a flat plate, without being formed to have a concave shape.

A thickness of the second flexible portion 66 corresponding to the second diaphragm is designed to be larger than a thickness of the first flexible portion 42. This enables a resonance frequency of the entirety of the first diaphragm (the first flexible portion 42 and the first piezoelectric element 33) to be closer to a resonance frequency of the second diaphragm (the second flexible portion 66). This makes it possible to provide a resonance configuration, and thus to provide a high-level pump function due to a resonance effect.

As illustrated in B of FIG. 15, the second flexible portion 66 of the second resonance plate 65 may be curved toward the first flexible portion 42 to have a concave shape in the reference state. Thus, the initial volume of the flow path space S1 can be decreased. Therefore, the rate of volume variation can be made higher, as represented by the formula (1). This makes it possible to provide a high-level pump function.

Only one piezoelectric element is used in the fluid control apparatus 64 according to the present embodiment, and this makes it possible to reduce costs for parts. Further, bonding of a piezoelectric element is only performed once, and this makes it possible to simplify steps of producing the fluid control apparatus 64. Furthermore, this also makes it possible to shorten the time necessary for the production.

In the configuration illustrated in A of FIG. 15, there is no need to form the second flexible portion 66 such that the second flexible portion 66 has a concave shape. This results in being able to simplify production steps, and thus to shorten the time necessary for the production. On the other hand, the configuration illustrated in B of FIG. 15 provides a high-level pump function.

Other Embodiments

The present technology is not limited to the embodiments described above, and can achieve various other embodiments.

FIG. 16 schematically illustrates examples of a configuration of a fluid control apparatus according to other embodiments.

In a fluid control apparatus 70 illustrated in FIG. 16, a groove 73 is formed near an outer peripheral portion of each flexible portion (a first flexible portion 71, a second flexible portion 72), as viewed from the up-and-down direction (the Z direction).

A portion near the outer peripheral portion is a region that is near the outer peripheral portion and situated further inward than the outer peripheral portion. For example, it is assumed that a width of a portion of a flexible portion that is largest when the flexible portion is viewed from the up-and-down direction is represented by a maximum width. The region near the outer peripheral portion can be determined on the basis of the maximum width.

For example, a region situated at a distance of 25% of the maximum width that is measured from the outer peripheral portion can be determined to be the region near the outer peripheral portion. Of course, a region situated at a distance less than 25% of the maximum width may be determined to be the region near the outer peripheral portion.

Typically, the groove 73 is formed on all of the periphery along the outer peripheral portion of the flexible portion, as viewed from the up-and-down direction. Without being limited thereto, the groove 73 may be formed intermittently at specified intervals.

Further, a plurality of the grooves 73 may be concentrically formed on all of the periphery of the flexible portion.

In the example illustrated in A of FIG. 16, the groove 73 is formed on all of the periphery of a lower surface 74 of the first flexible portion 71, as viewed from the up-and-down direction. Further, the groove 73 is formed on all of the periphery of an upper surface 75 of the second flexible portion 72, as viewed from the up-and-down direction. The groove 73 formed in the first flexible portion 71 and the groove 73 formed in the second flexible portion 72 coincide, as viewed from the up-and-down direction.

In the example illustrated in B of FIG. 16, the groove 73 is formed on all of the periphery of an upper surface 76 of the first flexible portion 71, as viewed from the up-and-down direction. Further, the groove 73 is formed on all of the periphery of a lower surface 77 of the second flexible portion 72, as viewed from the up-and-down direction. The groove 73 formed in the first flexible portion 71 and the groove 73 formed in the second flexible portion 72 coincide, as viewed from the up-and-down direction.

In the example illustrated in C of FIG. 16, two grooves 73 are concentrically formed on all of the periphery of the lower surface 74 of the first flexible portion 71, as viewed from the up-and-down direction. Further, two grooves 73 are concentrically formed on all of the periphery of the upper surface 75 of the second flexible portion 72, as viewed from the up-and-down direction. Each of the two grooves 73 formed in the first flexible portion 71 and a corresponding one of the two grooves 73 formed in the second flexible portion 72 coincide, as viewed from the up-and-down direction.

In the example illustrated in B of FIG. 16, the groove 73 is formed on all of the periphery of each of the upper surface 76 and the lower surface 74 of the first flexible portion 71, as viewed from the up-and-down direction. The two grooves 73 are concentrically formed, as viewed from the up-and-down direction.

Further, the groove 73 is formed on all of the periphery of each of the lower surface 77 and the upper surface 75 of the second flexible portion 72, as viewed from the up-and-down direction. The two grooves 73 are concentrically formed, as viewed from the up-and-down direction.

Each of the two grooves 73 formed in the first flexible portion 71 and a corresponding one of the two grooves 73 formed in the second flexible portion 72 coincide, as viewed from the up-and-down direction.

The formation of the groove 73 results in easily deforming a portion in which the groove 73 is formed. This makes it possible to optimize an amount of deformation of the resonance plate and a shape of the deformed resonance plate, the deformation of the resonance plate being performed due to pressure being applied upon bonding the piezoelectric element.

Further, stress caused in the flexible portion is increased in the outer peripheral portion of the piezoelectric element bonded to the flexible portion. Thus, when the groove 73 is formed at a position based on the outer peripheral portion of the piezoelectric element, this makes it possible to relax the stress caused in the flexible portion. This results in being able to prevent the flexible portion from being broken.

Note that examples of the position based on the outer peripheral portion of the piezoelectric element include any positions determined on the basis of the outer peripheral portion of the piezoelectric element.

The examples of the position based on the outer peripheral portion include a position that is situated in the outer peripheral portion of the piezoelectric element, as viewed from the up-and-down direction, a position that is situated further outward than the outer peripheral portion of the piezoelectric element by a specified length, as viewed from the up-and-down direction, and a position that is situated further inward than the outer peripheral portion of the piezoelectric element by the specified length, as viewed from the up-and-down direction. Note that the specified length may be set discretionarily.

Of course, the examples of the position based on the outer peripheral portion of the piezoelectric element may include positions that are set using any other methods.

Further, when the piezoelectric element is bonded to the flexible portion using an adhesive, a variation in a resonance frequency of the entirety of the flexible portion and the piezoelectric element may occur depending on an amount of the adhesive.

On the other hand, the appropriate formation of the groove 73 makes it possible to reduce the variation in resonance frequency.

For example, the appropriate formation of the groove 73 easily enables a resonance frequency of the first flexible portion 71 and a resonance frequency of the second flexible portion to be closer to each other.

A position at which the groove 73 is formed, the number of grooves 73, a width and depth of the groove 73, and the like are not limited, and may be designed discretionarily. These parameters have a close relationship with, for example, a resonance frequency of the resonance plate and an amount of deformation of the resonance plate after the piezoelectric element is bonded. Thus, the parameters are desired to be determined in consideration of the resonance frequency and the deformation amount.

A method for forming the groove 73 is also not limited. For example, any processing technology such as etching or laser processing may be used. The groove 73 can be formed at the same time as formation of the resonance plate using, for example, etching or laser processing.

[Regarding Electronic Apparatus]

The application of the above-described fluid control apparatuses according to the present technology is not particularly limited, and, for example, the fluid control apparatuses can each be mounted on an electronic apparatus. Each of the fluid control apparatuses enables air in an electronic apparatus to be discharged to the outside, or enables air to be intaken into an electronic apparatus from the outside.

For example, each of the fluid control apparatuses can be used for the various purposes, such as using in a pressure generation device used by being worn on a human body, using in a small cooling device, or using in a pump used for a pneumatic actuator in, for example, a robot.

As a specific example, each of the fluid control apparatuses described above may be used as a cooling device that sprays fluid upon a heating element in an electronic apparatus to suppress heating. For example, the fluid control apparatus may be mounted on a mobile apparatus such as a cellular phone to enable cooling.

Further, each of the fluid control apparatuses described above may be mounted on an electronic apparatus such as a tactile sense providing apparatus. This makes it possible to provide a pseudo sense of pressure or a pseudo tactile sense.

Furthermore, each of the fluid control apparatuses described above may be mounted on an electronic apparatus such as a sphygmomanometer.

Moreover, each of the fluid control apparatuses described above may be applied to an artificial muscle that is a telescopic actuator that expands and contracts by air pressure, the telescopic actuator being made of, for example, rubber.

Each of the fluid control apparatuses can be made smaller. Thus, an electronic apparatus easily has the fluid control apparatus built in. Further, the application of the fluid control apparatus is very advantageous in making an electronic apparatus smaller. Furthermore, each of the fluid control apparatuses exhibits a high performance. This makes it possible to provide a high-performance electronic apparatus for each purpose.

The respective configurations of the fluid control apparatus, the flow-path space forming portion, the intake space forming portion, the discharge space forming portion, the flow path space, the intake space, the discharge space, the drive mechanism, the piezoelectric element, the groove, and the like; the respective methods; and the like described with reference to the respective figures are merely embodiments, and any modifications may be made thereto without departing from the spirit of the present technology. In other words, for example, any other configurations or methods for purpose of practicing the present technology may be adopted.

In the present disclosure, wording such as “substantially”, “almost”, and “approximately” is used as appropriate in order to facilitate the understanding of the description. On the other hand, whether the wording such as “substantially”, “almost”, and “approximately” is used does not result in a clear difference.

In other words, in the present disclosure, expressions, such as “center”, “middle”, “uniform”, “equal”, “similar”, “orthogonal”, “parallel”, “symmetric”, “extend”, “axial direction”, “columnar”, “cylindrical”, “ring-shaped”, and “annular” that define, for example, a shape, a size, a positional relationship, and a state respectively include, in concept, expressions such as “substantially the center/substantial center”, “substantially the middle/substantially middle”, “substantially uniform”, “substantially equal”, “substantially similar”, “substantially orthogonal”, “substantially parallel”, “substantially symmetric”, “substantially extend”, “substantially axial direction”, “substantially columnar”, “substantially cylindrical”, “substantially ring-shaped”, and “substantially annular”.

For example, the expressions such as “center”, “middle”, “uniform”, “equal”, “similar”, “orthogonal”, “parallel”, “symmetric”, “extend”, “axial direction”, “columnar”, “cylindrical”, “ring-shaped”, and “annular” also respectively include states within specified ranges (such as a range of +/−10%), with expressions such as “exactly the center/exact center”, “exactly the middle/exactly middle”, “exactly uniform”, “exactly equal”, “exactly similar”, “completely orthogonal”, “completely parallel”, “completely symmetric”, “completely extend”, “fully axial direction”, “perfectly columnar”, “perfectly cylindrical”, “perfectly ring-shaped”, and “perfectly annular” being respectively used as references.

Thus, an expression that does not include the wording such as “substantially”, “almost”, and “approximately” can also include, in concept, a possible expression including the wording such as “substantially”, “almost”, and “approximately”. Conversely, a state expressed using the expression including the wording such as “substantially”, “almost”, and “approximately” may include a state of “exactly/exact”, “completely”, “fully”, or “perfectly”.

In the present disclosure, an expression using “-er than” such as “being larger than A” and “being smaller than A” comprehensively includes, in concept, an expression that includes “being equal to A” and an expression that does not include “being equal to A”. For example, “being larger than A” is not limited to the expression that does not include “being equal to A”, and also includes “being equal to or greater than A”. Further, “being smaller than A” is not limited to “being less than A”, and also includes “being equal to or less than A”.

When the present technology is carried out, it is sufficient if a specific setting or the like is adopted as appropriate from expressions included in “being larger than A” and expressions included in “being smaller than A”, in order to provide the effects described above.

At least two of the features of the present technology described above can also be combined. In other words, the various features described in the respective embodiments may be combined discretionarily regardless of the embodiments. Further, the various effects described above are not limitative but are merely illustrative, and other effects may be provided.

Note that the present technology may also take the following configurations.

(1) A fluid control apparatus, including:

• • a flow-path space forming portion that includes a flexible portion that have flexibility, and a facing portion that faces the flexible portion, the flow-path space forming portion forming a flow path space between the flexible portion and the facing portion, the flow path space being a flow path of fluid;
  • an inflow opening that is provided to an outer peripheral portion of the flow path space, as viewed from a facing direction in which the flexible portion and the facing portion face each other, the inflow opening being an opening through which the fluid flows into the flow path space;
  • an outflow opening that is provided to a portion, in the outer peripheral portion of the flow path space, that is different from a portion, in the outer peripheral portion of the flow path space, that is provided with the inflow opening, as viewed from the facing direction, the outflow opening being an opening through which the fluid flows out of the flow path space; and
  • a drive mechanism that bends the flexible portion to increase or decrease the volume of the flow path space,
  • the flexible portion being configured such that at least a portion of a region of the flexible portion is curved toward the facing portion to have a concave shape in a reference state in which the flexible portion is not bent by the drive mechanism, the region of the flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.
    (2) The fluid control apparatus according to (1), in which
  • the flexible portion is configured such that a center portion of the flexible portion as viewed from the facing direction is curved toward the facing portion to have a concave shape in the reference state.
    (3) The fluid control apparatus according to (1) or (2), in which
  • the flexible portion has a shape obtained by a plate member being deformed and curved toward the facing portion to have a concave shape in the reference state.
    (4) The fluid control apparatus according to any one of (1) to (3), in which
  • the drive mechanism bends the flexible portion such that a concave portion of the flexible portion in the reference state is moved by a largest distance in the facing direction.
    (5) The fluid control apparatus according to any one of (1) to (4), in which
  • the drive mechanism includes a piezoelectric element that is connected to a certain surface of the flexible portion that is situated opposite to another surface of the flexible portion that faces the facing portion.
    (6) The fluid control apparatus according to any one of (1) to (5), in which
  • when the flexible portion is a first flexible portion, the facing portion is a second flexible portion that has flexibility,
  • the drive mechanism bends the second flexible portion, and
  • the second flexible portion is configured such that at least a portion of a region of the second flexible portion is curved toward the first flexible portion to have a concave shape in the reference state, the region of the second flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.
    (7) The fluid control apparatus according to (6), in which
  • the first flexible portion and the second flexible portion are configured to resonate with each other.
    (8) The fluid control apparatus according to (7), in which
  • the drive mechanism includes
    • a first piezoelectric element that is connected to a certain surface of the first flexible portion that is opposite to another surface of the first flexible portion that faces the second flexible portion, and
    • a second piezoelectric element that is connected to a certain surface of the second flexible portion that is opposite to another surface of the second flexible portion that faces the first flexible portion, and
  • the drive mechanism is configured such that a resonance frequency of the entirety of the first flexible portion and the first piezoelectric element is closer to a resonance frequency of the entirety of the second flexible portion and the second piezoelectric element.
    (9) The fluid control apparatus according to any one of (1) to (5), in which
  • when the flexible portion is a first flexible portion, the facing portion is a second flexible portion that has flexibility, and
  • the first flexible portion and the second flexible portion are configured to resonate with each other.
    (10) The fluid control apparatus according to (9), in which
  • the drive mechanism includes a piezoelectric element that is connected to a certain surface of the first flexible portion that is situated opposite to another surface of the first flexible portion that faces the second flexible portion, and
  • the drive mechanism is configured such that a resonance frequency of the second flexible portion is closer to a resonance frequency of the entirety of the first flexible portion and the first piezoelectric element.
    (11) The fluid control apparatus according to (10), in which
  • the second flexible portion has a larger thickness than the first flexible portion.
    (12) The fluid control apparatus according to any one of (8) to (11), in which
  • the second flexible portion is configured such that the at least the portion of the region of the second flexible portion is curved toward the first flexible portion to have a concave shape in the reference state, the region of the second flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.
    (13) The fluid control apparatus according to any one of (1) to (12), in which
  • the flexible portion includes a groove that is formed near an outer peripheral portion of the flexible portion, as viewed from the facing direction.
    (14) The fluid control apparatus according to (13), in which
  • the drive mechanism includes a piezoelectric element that is connected to a certain surface of the flexible portion that is situated opposite to another surface of the flexible portion that faces the facing portion, and
  • the groove is formed at a position based on an outer peripheral portion of the piezoelectric element, as viewed from the facing direction.
    (15) The fluid control apparatus according to any one of (1) to (14), further including:
  • an inlet through which the fluid is intaken into the fluid control apparatus;
  • an intake space forming portion that forms an intake space through which the inlet and the inflow opening communicate with each other;
  • an outlet through which the fluid is discharged from the fluid control apparatus; and
  • a discharge space forming portion that forms a discharge space through which the outlet and the outflow opening communicate with each other.
    (16) The fluid control apparatus according to any one of (1) to (15), in which
  • the flow-path space forming portion includes
    • a first plate member that is made of a metallic material and includes the flexible portion in a center region of the first plate member, as viewed from the facing direction,
    • a second plate member that is made of a metallic material and includes the facing portion in a center region of the second plate member, as viewed from the facing direction, and
    • a spacer member that has a specified thickness and includes an opening in a center region of the spacer member, as viewed from the facing direction, the spacer member being arranged between the first plate member and the second plate member, the spacer member being joined to the first plate member and to the second plate member using diffused junction.
      (17) The fluid control apparatus according to (16), in which
  • the spacer member includes
    • an inlet opening that is configured to communicate with an outer peripheral portion of the center opening, and
    • an outlet opening that is configured to communicate with the outer peripheral portion of the center opening, the outlet opening being provided to a portion, in the spacer member, that is different from a portion, in the spacer member, that is provided with the inlet opening.
      (18) The fluid control apparatus according to (17), in which
  • an inlet through which the fluid is intaken into the fluid control apparatus is formed in at least one of a region, in the first plate member, that covers the inlet opening, or a region, in the second plate member, that covers the inlet opening, and
  • an outlet through which the fluid is discharged from the fluid control apparatus is formed in at least one of a region, in the first plate member, that covers the outlet opening, or a region, in the second plate member, that covers the outlet opening.
    (19) An electronic apparatus, including
  • a fluid control apparatus that includes
    • a flow-path space forming portion that includes a flexible portion that have flexibility, and a facing portion that faces the flexible portion, the flow-path space forming portion forming a flow path space between the flexible portion and the facing portion, the flow path space being a flow path of fluid,
    • an inflow opening that is provided to an outer peripheral portion of the flow path space, as viewed from a facing direction in which the flexible portion and the facing portion face each other, the inflow opening being an opening through which the fluid flows into the flow path space,
    • an outflow opening that is provided to a portion, in the outer peripheral portion of the flow path space, that is different from a portion, in the outer peripheral portion of the flow path space, that is provided with the inflow opening, as viewed from the facing direction, the outflow opening being an opening through which the fluid flows out of the flow path space, and
    • a drive mechanism that bends the flexible portion to increase or decrease the volume of the flow path space,
  • the flexible portion being configured such that at least a portion of a region of the flexible portion is curved toward the facing portion to have a concave shape in a reference state in which the flexible portion is not bent by the drive mechanism, the region of the flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

REFERENCE SIGNS LIST

• • Gm minimum gap
  • H reference facing distance
  • M amplitude
  • S1 flow path space
  • S2 intake space
  • S3 discharge space
  • Z amount of concave
  • 1, 27, 64, 70 fluid control apparatus
  • 2 flow-path space forming portion
  • 3 inflow opening
  • 4 outflow opening
  • 5 drive mechanism
  • 6 upper surface member
  • 7 lower surface member
  • 8a, 8b, 30 spacer member
  • 11 outer peripheral portion of flow path space
  • 15 center portion of upper surface member
  • 17 piezoelectric element
  • 29 first resonance plate
  • 31, 65 second resonance plate
  • 33 first piezoelectric element
  • 34 second piezoelectric element
  • 37 center portion of first flexible portion
  • 42, 71 first flexible portion
  • 43a, 43b outlet
  • 49, 66, 72 second flexible portion
  • 50b inlet
  • 51 center portion of second flexible portion
  • 73 groove

Claims

1. A fluid control apparatus, comprising:

a flow-path space forming portion that includes a flexible portion that have flexibility, and a facing portion that faces the flexible portion, the flow-path space forming portion forming a flow path space between the flexible portion and the facing portion, the flow path space being a flow path of fluid;

an inflow opening that is provided to an outer peripheral portion of the flow path space, as viewed from a facing direction in which the flexible portion and the facing portion face each other, the inflow opening being an opening through which the fluid flows into the flow path space;

an outflow opening that is provided to a portion, in the outer peripheral portion of the flow path space, that is different from a portion, in the outer peripheral portion of the flow path space, that is provided with the inflow opening, as viewed from the facing direction, the outflow opening being an opening through which the fluid flows out of the flow path space; and

a drive mechanism that bends the flexible portion to increase or decrease the volume of the flow path space,

the flexible portion being configured such that at least a portion of a region of the flexible portion is curved toward the facing portion to have a concave shape in a reference state in which the flexible portion is not bent by the drive mechanism, the region of the flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

2. The fluid control apparatus according to claim 1, wherein

the flexible portion is configured such that a center portion of the flexible portion as viewed from the facing direction is curved toward the facing portion to have a concave shape in the reference state.

3. The fluid control apparatus according to claim 1, wherein

the flexible portion has a shape obtained by a plate member being deformed and curved toward the facing portion to have a concave shape in the reference state.

4. The fluid control apparatus according to claim 1, wherein

the drive mechanism bends the flexible portion such that a concave portion of the flexible portion in the reference state is moved by a largest distance in the facing direction.

5. The fluid control apparatus according to claim 1, wherein

the drive mechanism includes a piezoelectric element that is connected to a certain surface of the flexible portion that is situated opposite to another surface of the flexible portion that faces the facing portion.

6. The fluid control apparatus according to claim 1, wherein

when the flexible portion is a first flexible portion, the facing portion is a second flexible portion that has flexibility,

the drive mechanism bends the second flexible portion, and

the second flexible portion is configured such that at least a portion of a region of the second flexible portion is curved toward the first flexible portion to have a concave shape in the reference state, the region of the second flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

7. The fluid control apparatus according to claim 6, wherein

the first flexible portion and the second flexible portion are configured to resonate with each other.

8. The fluid control apparatus according to claim 7, wherein

the drive mechanism includes a first piezoelectric element that is connected to a certain surface of the first flexible portion that is opposite to another surface of the first flexible portion that faces the second flexible portion, and a second piezoelectric element that is connected to a certain surface of the second flexible portion that is opposite to another surface of the second flexible portion that faces the first flexible portion, and

the drive mechanism is configured such that a resonance frequency of the entirety of the first flexible portion and the first piezoelectric element is closer to a resonance frequency of the entirety of the second flexible portion and the second piezoelectric element.

9. The fluid control apparatus according to claim 1, wherein

when the flexible portion is a first flexible portion, the facing portion is a second flexible portion that has flexibility, and

the first flexible portion and the second flexible portion are configured to resonate with each other.

10. The fluid control apparatus according to claim 9, wherein

the drive mechanism includes a piezoelectric element that is connected to a certain surface of the first flexible portion that is situated opposite to another surface of the first flexible portion that faces the second flexible portion, and

the drive mechanism is configured such that a resonance frequency of the second flexible portion is closer to a resonance frequency of the entirety of the first flexible portion and the first piezoelectric element.

11. The fluid control apparatus according to claim 10, wherein

the second flexible portion has a larger thickness than the first flexible portion.

12. The fluid control apparatus according to claim 8, wherein

the second flexible portion is configured such that the at least the portion of the region of the second flexible portion is curved toward the first flexible portion to have a concave shape in the reference state, the region of the second flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.

13. The fluid control apparatus according to claim 1, wherein

the flexible portion includes a groove that is formed near an outer peripheral portion of the flexible portion, as viewed from the facing direction.

14. The fluid control apparatus according to claim 13, wherein

the drive mechanism includes a piezoelectric element that is connected to a certain surface of the flexible portion that is situated opposite to another surface of the flexible portion that faces the facing portion, and

the groove is formed at a position based on an outer peripheral portion of the piezoelectric element, as viewed from the facing direction.

15. The fluid control apparatus according to claim 1, further comprising:

an inlet through which the fluid is intaken into the fluid control apparatus;

an intake space forming portion that forms an intake space through which the inlet and the inflow opening communicate with each other;

an outlet through which the fluid is discharged from the fluid control apparatus; and

a discharge space forming portion that forms a discharge space through which the outlet and the outflow opening communicate with each other.

16. The fluid control apparatus according to claim 1, wherein

the flow-path space forming portion includes a first plate member that is made of a metallic material and includes the flexible portion in a center region of the first plate member, as viewed from the facing direction, a second plate member that is made of a metallic material and includes the facing portion in a center region of the second plate member, as viewed from the facing direction, and a spacer member that has a specified thickness and includes an opening in a center region of the spacer member, as viewed from the facing direction, the spacer member being arranged between the first plate member and the second plate member, the spacer member being joined to the first plate member and to the second plate member using diffused junction.

17. The fluid control apparatus according to claim 16, wherein

the spacer member includes an inlet opening that is configured to communicate with an outer peripheral portion of the center opening, and an outlet opening that is configured to communicate with the outer peripheral portion of the center opening, the outlet opening being provided to a portion, in the spacer member, that is different from a portion, in the spacer member, that is provided with the inlet opening.

18. The fluid control apparatus according to claim 17, wherein

an inlet through which the fluid is intaken into the fluid control apparatus is formed in at least one of a region, in the first plate member, that covers the inlet opening, or a region, in the second plate member, that covers the inlet opening, and

an outlet through which the fluid is discharged from the fluid control apparatus is formed in at least one of a region, in the first plate member, that covers the outlet opening, or a region, in the second plate member, that covers the outlet opening.

19. An electronic apparatus, comprising

a fluid control apparatus that includes a flow-path space forming portion that includes a flexible portion that have flexibility, and a facing portion that faces the flexible portion, the flow-path space forming portion forming a flow path space between the flexible portion and the facing portion, the flow path space being a flow path of fluid, an inflow opening that is provided to an outer peripheral portion of the flow path space, as viewed from a facing direction in which the flexible portion and the facing portion face each other, the inflow opening being an opening through which the fluid flows into the flow path space, an outflow opening that is provided to a portion, in the outer peripheral portion of the flow path space, that is different from a portion, in the outer peripheral portion of the flow path space, that is provided with the inflow opening, as viewed from the facing direction, the outflow opening being an opening through which the fluid flows out of the flow path space, and a drive mechanism that bends the flexible portion to increase or decrease the volume of the flow path space,

the flexible portion being configured such that at least a portion of a region of the flexible portion is curved toward the facing portion to have a concave shape in a reference state in which the flexible portion is not bent by the drive mechanism, the region of the flexible portion being situated further inward than the outer peripheral portion of the flow path space, as viewed from the facing direction.