Patent Description:
Hitherto, as described in <CIT>, <CIT>, and <CIT>, various types of pumps for conveying fluid by using a piezoelectric body have been devised.

The pumps described in <CIT>, <CIT>, and <CIT> use a vibration of the piezoelectric body to convey fluid. By using the piezoelectric body, the pumps described in <CIT>, <CIT>, and <CIT> are reduced in size and height.

Further, the pumps described in <CIT>, <CIT>, and <CIT> each include a rectifying mechanism that conveys fluid in one direction.

Further pumps having film valves in the pump chamber opposing a vibrating plate, are known from <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

However, in the pump configurations described in <CIT>, <CIT>, and <CIT>, there are some restrictions on pump characteristics of each pump. The pump characteristics are represented by a pressure or a flow rate, and the higher the pressure is, the better the pump characteristics are, and the higher the flow rate is, the better the pump characteristics are.

Further, in the pump configurations described in <CIT>, <CIT>, and <CIT>, the pump characteristics of each pump may be limited due to the rectifying mechanism.

Therefore, an object of the present invention is to provide a pump having a rectifying function and having excellent pump characteristics.

According to the present invention, a pump as defined by claim <NUM> is provided to address the above issues, wherein preferred embodiments of the invention are laid down in the dependent claims. Thus, a pump of the present invention includes a plate-shaped member, a flow path forming member, a pump chamber, and a first film valve. The plate-shaped member includes a vibrating plate with a piezoelectric element on one principal surface, a support plate, and a plurality of support members that connect the vibrating plate and the support plate and support the vibrating plate so that the vibrating plate is configured to vibrate in a principal surface direction, and includes a first vent hole between the plurality of support members. The flow path forming member is disposed so as to face the plate-shaped member, and has a second vent hole in a portion facing the plate-shaped member. The pump chamber is formed so as to be surrounded by the plate-shaped member, the flow path forming member, and a side wall member connected to the plate-shaped member and the flow path forming member, and has a central space communicating with the second vent hole and an outer edge space communicating with the first vent hole. The first film valve is disposed in the pump chamber. The first film valve is in contact with the vibrating plate and the flow path forming member when the pressure in the central space is lower than the pressure in the outer edge space.

With this configuration, in an aspect in which the second vent hole serves as a suction port and the first vent hole serves as a discharge port, a backflow of fluid from a gap side to the pump chamber at the time of suction is suppressed.

In addition, the pump of the present invention preferably has the following configuration. The first film valve is disposed such that the second vent hole is located at a position within a space surrounded by an outer end of the first film valve in a plan view, and is fixed to the vibrating plate or the flow path forming member so that a portion on an outer end side can be deformed.

With this configuration, the above-described configuration for suppressing the backflow can be realized with a simple configuration.

In addition, the pump of the present invention preferably has the following configuration. In a plan view, a central portion of the vibrating plate has a thick portion whose thickness from the one principal surface to another principal surface is thicker than a thickness of an outer end of the vibrating plate. The first film valve has an annular shape, and an annular inner end of the first film valve is disposed along an outer edge of the thick portion.

With this configuration, the first film valve is easily and highly accurately set at a position where the above-described operation can be realized.

In addition, the pump of the present invention may have the following configuration. The pump includes a second film valve. The second film valve is disposed at a peripheral edge of the second vent hole and at a position closer to the second vent hole than the position where the first film valve is disposed in a plan view. The second film valve is in contact with the vibrating plate and the flow path forming member when the pressure in the central space is higher than the pressure in the outer edge space in the pump chamber.

With this configuration, when the fluid stored in the pump chamber is discharged to a gap at an outer edge, leakage of the fluid from the second vent hole, which is the suction port, is further suppressed.

In addition, in the pump of the present invention, it is preferable that the second film valve be fixed to the vibrating plate or the flow path forming member so that a portion on an outer end side of the second film valve can be deformed.

With this configuration, the second film valve can be realized by a simple configuration while realizing the above-described functions.

In addition, the pump of the present invention may have the following configuration. The pump includes the plate-shaped member, the flow path forming member, the pump chamber, and a third film valve.

The plate-shaped member includes the vibrating plate with a piezoelectric element on one principal surface, the support plate, and the plurality of support members that connect the vibrating plate and the support plate and support the vibrating plate so that the vibrating plate is configured to vibrate in a principal surface direction, and includes the first vent hole between the plurality of support members. The flow path forming member is disposed so as to face the plate-shaped member, and has the second vent hole in a portion facing the plate-shaped member.

The pump chamber is formed so as to be surrounded by the plate-shaped member, the flow path forming member, and a side wall member connected to the plate-shaped member and the flow path forming member, and has a central space communicating with the second vent hole and an outer edge space communicating with the first vent hole. The third film valve is disposed in the pump chamber. The third film valve is in contact with the vibrating plate and the flow path forming member when the pressure in the central space is higher than the pressure in the outer edge space.

With this configuration, in an aspect in which the second vent hole serves as a discharge port and the first vent hole serves as a suction port, the leakage of fluid to the gap side at the time of discharge is suppressed.

In addition, the pump of the present invention preferably has the following configuration. The third film valve is disposed such that the second vent hole is located at a position within a space surrounded by an outer end of the third film valve in a plan view, and is fixed to the vibrating plate or the flow path forming member so that a portion on a center side may be deformed.

With this configuration, the above-described configuration for suppressing the leakage can be realized with a simple configuration.

In addition, the pump of the present invention preferably has the following configuration. In a plan view, a central portion of the vibrating plate has a thick portion whose thickness from the one principal surface to another principal surface is thicker than a thickness of an outer end of the vibrating plate. The third film valve has an annular shape, and an annular inner end of the third film valve is disposed along the outer edge of the thick portion.

With this configuration, the third film valve is easily and highly accurately set at a position where the above-described operation can be realized.

In addition, the pump of the present invention may have the following configuration. The pump includes a fourth film valve. The fourth film valve is disposed at a peripheral edge of the second vent hole and at a position closer to the second vent hole than the position where the third film valve is disposed in a plan view. The fourth film valve is in contact with the vibrating plate and the flow path forming member when the pressure in the central space is lower than the pressure in the outer edge space in the pump chamber.

With this configuration, when the fluid is sucked into the pump chamber from the gap at the outer edge, a backflow of the fluid from the second vent hole, which is the discharge port, is further suppressed.

In addition, the pump of the present invention preferably has the following configuration. The fourth film valve is fixed to the vibrating plate or the flow path forming member so that a portion on a center side can be deformed.

With this configuration, the fourth film valve can be realized by a simple configuration while realizing the above-described functions.

In addition, the pump of the present invention may have the following configuration. The pump includes the flat plate-shaped member, the flow path forming member, the pump chamber, a fifth film valve, a third vent hole, and a fourth vent hole. The flat plate-shaped member includes the vibrating plate with the piezoelectric element disposed on one principal surface, the support plate, and a support member that connects an outer edge of the vibrating plate and the support plate and supports the vibrating plate so that the vibrating plate is configured to vibrate in a principal surface direction. The flow path forming member is disposed so as to face the flat plate-shaped member. The pump chamber is formed so as to be surrounded by the flat plate-shaped member, the flow path forming member, and the side wall member connected to the flat plate-shaped member and the flow path forming member. The fifth film valve is fixed to the flat plate-shaped member or the flow path forming member, and is disposed in the pump chamber so as to overlap the vibrating plate in a plan view. The third vent hole is formed in the flat plate-shaped member, and the fourth vent hole is formed in the flow path forming member. The third vent hole and the fourth vent hole are disposed at positions where the fifth film valve is sandwiched therebetween in a plan view. The fifth film valve changes the flow path resistance between the third vent hole and the fourth vent hole by switching a mode in which the fifth film valve is in contact with the flow path forming member or the flat plate-shaped member and a mode in which the fifth film valve is not in contact with the flow path forming member and the flat plate-shaped member in accordance with a vibration of the vibrating plate.

With this configuration, the fifth film valve suppresses a backflow of fluid in the pump chamber. Thus, the fluid can be conveyed from an outer edge space to a central space of the pump chamber or from the central space to the outer edge space.

In this case, in the pump of the present invention, it is preferable that the fifth film valve be configured to suppress discharge of the fluid from the central space to the outer edge space of the pump chamber and to realize influx of the fluid from the outer edge space to the central space. With this configuration, since the vibrating plate and the flow path forming member come close to each other at the time of discharge, the fifth film valve is likely to come into contact with the flow path forming member or the flat plate-shaped member, and the vibrating plate and the flow path forming member are separated from each other at the time of suction, the fifth film valve is unlikely to come into contact with the flow path forming member or the flat plate-shaped member. Therefore, it is easy to suppress the backflow at the time of discharge and it is easy to promote an inflow at the time of suction.

In addition, the pump of the present invention preferably has any one of the following configurations. The flow path forming member includes, in a plan view, a protruding portion that protrudes toward the vibrating plate at a position where the flow path forming member overlaps the fifth film valve. The vibrating plate includes, in a plan view, a protruding portion that protrudes toward the flow path forming member at a position where the flow path forming member overlaps the fifth film valve.

With these configurations, the switching between the mode in which the fifth film valve is in contact with the flow path forming member or the flat plate-shaped member, and the mode in which the fifth film valve is not in contact can be more quickly and reliably realized, and the backflow at the time of discharge can be further suppressed, and the inflow at the time of suction can be more easily promoted.

In addition, it is preferable that the third vent hole of the pump of the present invention be formed in the flat plate-shaped member.

With this configuration, it is possible to easily form a conduction path of a drive signal to the piezoelectric element.

In addition, the pump of the present invention preferably has the following configuration. The third vent hole is formed on an outer edge side relative to the position where the fifth film valve is disposed in the flat plate-shaped member in a plan view. The fourth vent hole is formed on the center side relative to the position overlapping the fifth film valve in the flow path forming member in a plan view.

With this configuration, since flexibility of the support member is higher than the flexibility of the vibrating plate, it is possible to vibrate the vibrating plate largely. Therefore, with this configuration, a displacement amount at the position where the fifth film valve is disposed can be increased, and the switching between the mode in which the fifth film valve is in contact with the flow path forming member or the flat plate-shaped member and the mode in which the fifth film valve is not in contact can be more quickly and reliably realized.

In addition, in the pump of the present invention, it is preferable that the fourth vent hole overlap a vibration node of the vibrating plate.

With this configuration, the backflow is reliably suppressed without using a check valve.

In addition, in the pump of the present invention, the fourth vent hole may overlap an antinode of the center of the vibrating plate and may include the check valve that prevents the backflow from the outside to the pump chamber from occurring.

With this configuration, even when the discharge is performed from a portion overlapping the antinode of the vibration, the backflow is suppressed. Further, by utilizing the antinode of the vibration, it is possible to realize the opening and closing of the check valve more quickly and reliably.

In addition, in the pump of the present invention, it is preferable that the support member be formed of a material or a shape having higher flexibility than the vibrating plate.

With this configuration, even when the outer edge of the vibrating plate is supported, the vibration of the vibrating plate is promoted.

In addition, in the pump of the present invention, the support member preferably has a shape of a beam along the outer edge of the vibrating plate.

With this configuration, the flexibility of the support member can be made to be higher than the flexibility of the vibrating plate with a simple structure.

In addition, in the pump of the present invention, it is preferable that the third vent hole be formed by a gap between the support members.

With this configuration, it is possible to particularly increase the displacement amount at the position where the fifth film valve is disposed. Therefore, it is possible to realize the switching more quickly and reliably between the mode in which the fifth film valve is in contact with the flow path forming member or the flat plate-shaped member and the mode in which the fifth film valve is not in contact with the flow path forming member and the flat plate-shaped member.

In addition, the pump of the present invention may have the following configuration. The third vent hole is formed on the center side relative to the position overlapping the fifth film valve in the vibrating plate in a plan view. The fourth vent hole is formed at a position overlapping the support member in the flow path forming member in a plan view.

With this configuration, it is possible to realize a configuration in which the fluid is sucked from the flow path forming member side and is discharged to the vibrating plate side.

According to the present invention, it is possible to realize excellent pump characteristics in a pump having a rectifying function.

A pump according to a first embodiment of the present invention will be described with reference to the drawings. <FIG> is an exploded perspective view of a pump <NUM> according to the first embodiment of the present invention. <FIG> is a cross-sectional view illustrating a configuration of a composite module of the pump <NUM> and a valve <NUM> according to the first embodiment of the present invention. Note that, in each of the drawings illustrating each embodiment below, for easy understanding of a description, the shapes of the respective constituent elements are exaggerated in part or as a whole.

As illustrated in <FIG> and <FIG>, the pump <NUM> includes a vibrating plate <NUM>, a piezoelectric element <NUM>, a film valve <NUM>, a joint member <NUM>, a flow path forming member <NUM>, a flow path forming member <NUM>, a cover member <NUM>, and a side wall member <NUM>.

The vibrating plate <NUM> has a disk shape. The vibrating plate <NUM> is formed of a material and a size capable of performing a bending vibration due to deformation (distortion) of the piezoelectric element <NUM>. The bending vibration is a vibration with a direction orthogonal to a plate-shaped member surface as a vibration direction. Further, the vibrating plate <NUM> is formed of a material and a size capable of vibrating at a predetermined resonant frequency.

The vibrating plate <NUM> is formed of a thin portion <NUM> and a thick portion <NUM>. The thick portion <NUM> has a shape protruding from one principal surface of the thin portion <NUM> and does not protrude from another principal surface. An outer shape of the thin portion <NUM> in a plan view and an outer shape of the thick portion <NUM> in a plan view are both circular. A diameter of the thick portion <NUM> is smaller than a diameter of the thin portion <NUM>. The thick portion <NUM> is disposed in a central portion of the thin portion <NUM> in a plan view. The center of the thick portion <NUM> and the center of the thin portion <NUM> in a plan view substantially coincide with each other. The thick portion <NUM> and the thin portion <NUM> are integrally formed.

A support plate <NUM> is disposed on an outer periphery of the vibrating plate <NUM> so as to be separated from the vibrating plate <NUM>. Between the vibrating plate <NUM> and the support plate <NUM>, there is a gap <NUM>. The vibrating plate <NUM> is connected to the support plate <NUM> by support members <NUM> formed in the gap <NUM>. The support member <NUM> has a spring property. Accordingly, the vibrating plate <NUM> is held by the support plate <NUM> so as to be able to vibrate with the support members <NUM> interposed therebetween. A member formed of the vibrating plate <NUM>, the support plate <NUM>, and the support members <NUM> corresponds to a "plate-shaped member" of the present invention. In addition, the gap <NUM> corresponds to a "first vent hole" of the present invention.

The piezoelectric element <NUM> includes a piezoelectric body and driving electrodes. The piezoelectric body has a disk shape. The driving electrodes are formed on both principal surfaces of the piezoelectric body. The shape of the piezoelectric body is distorted by a driving voltage applied to the driving electrode. That is, the piezoelectric element <NUM> is distorted by the application of the driving voltage.

The piezoelectric element <NUM> is in contact with a surface of the vibrating plate <NUM> opposite to a surface on which the thick portion <NUM> protrudes. Accordingly, when the driving voltage is applied to the piezoelectric element <NUM> and the piezoelectric element <NUM> is distorted, the stress due to the distortion of the piezoelectric element <NUM> acts on the vibrating plate <NUM>, and the vibrating plate <NUM> generates the above-described bending vibration.

The film valve <NUM> is made of a flexible material. The film valve <NUM> is realized by a lightweight and low rigidity material. For example, the film valve <NUM> is realized by a metal foil, a resin film, or the like. Note that the film valve <NUM> is more preferably a polyimide film. The film valve <NUM> corresponds to a "first film valve" of the present invention. For example, the film valve <NUM> has a thickness of <NUM>, and an outer diameter (diameter) of <NUM>.

The film valve <NUM> is disposed at a position such that a hole <NUM> is in a space surrounded by an outer end of the film valve <NUM> in a plan view.

The film valve <NUM> is disposed on the surface of the vibrating plate <NUM> on a side where the thick portion <NUM> protrudes. The film valve <NUM> has an annular shape. The film valve <NUM> is joined to the vibrating plate <NUM> by using an annular joint member <NUM>. More specifically, a portion having a predetermined width on an inner end side of the annular shape in the film valve <NUM> is joined to the vibrating plate <NUM> by the joint member <NUM>, and a portion on an outer end side is not joined. Accordingly, the film valve <NUM> is joined to the vibrating plate <NUM> in a state where a portion having a predetermined area on the outer end side can vibrate. For example, the joint member <NUM> has a thickness of <NUM> and an outer diameter (diameter) of <NUM>.

An inner end of the film valve <NUM> is located outside an outer circumference of the thick portion <NUM> and substantially in contact with the outer circumference. With this configuration, since the film valve <NUM> can be disposed with the thick portion <NUM> as a reference, so that the film valve <NUM> can be disposed easily and highly accurately.

A length of the film valve <NUM> in a radial direction excluding a portion joined to the joint member <NUM> is longer than an interval between the vibrating plate <NUM> and the flow path forming member <NUM>. As a result, the film valve <NUM> is easily in contact with the flow path forming member <NUM>. More preferably, while the vibrating plate <NUM> is vibrating, in a state where the vibrating plate <NUM> is most separated from the flow path forming member <NUM>, by a portion having a predetermined length from the outer end toward the center of the film valve <NUM> taking a shape in contact with the flow path forming member <NUM>, the film valve <NUM> can be easily in contact with the flow path forming member <NUM>.

The flow path forming member <NUM> is a plate-shaped member. The flow path forming member <NUM> is made of a material having high rigidity. The flow path forming member <NUM> has the hole <NUM> at substantially the center in a plan view. The hole <NUM> is a through-hole that penetrates through the flow path forming member <NUM> in a thickness direction. For example, a diameter of the hole <NUM> is about <NUM>. The hole <NUM> corresponds to a "second vent hole" of the present invention.

The flow path forming member <NUM> is disposed at a predetermined distance separated from a surface on a side in which the thick portion <NUM> in the vibrating plate <NUM> protrudes. At this time, the flow path forming member <NUM> is also disposed apart from the film valve <NUM>.

The flow path forming member <NUM> is a plate-shaped member. The flow path forming member <NUM> is made of a material having high rigidity. The flow path forming member <NUM> has a flow path opening <NUM>. The flow path opening <NUM> penetrates through the flow path forming member <NUM> in the thickness direction. The flow path opening <NUM> includes a central opening having a circular shape and a plurality of linear openings in a plan view. One ends of the plurality of linear openings in an extending direction communicate with the central opening, and the other ends reach the vicinity of the different outer ends of the flow path forming member <NUM>, respectively.

A cover member <NUM> is a plate-shaped member. The cover member <NUM> has a plurality of holes <NUM>. The plurality of holes <NUM> penetrate through the cover member <NUM> in the thickness direction. The plurality of holes <NUM> are formed near the different outer ends of the cover member <NUM>, respectively.

The flow path forming member <NUM>, the flow path forming member <NUM>, and the cover member <NUM> are laminated in this order, and joined, respectively. Accordingly, the hole <NUM>, the flow path opening <NUM>, and the plurality of holes <NUM> communicate sequentially in this order to form a flow path on a side where the thick portion <NUM> of the vibrating plate <NUM> protrudes.

The side wall member <NUM> is tubular and has high rigidity. The side wall member <NUM> is connected to the support plate <NUM> and the flow path forming member <NUM>.

With this configuration, the pump <NUM> has a pump chamber <NUM> that is a hollow space surrounded by the vibrating plate <NUM>, the support plate <NUM>, the flow path forming member <NUM>, and the side wall member <NUM>. The film valve <NUM> is disposed in the pump chamber <NUM>. Further, the pump chamber <NUM> communicates with the hole <NUM> and also with the gap <NUM>. For example, a height of the pump chamber <NUM> in a default state (a state in which the vibrating plate <NUM> is not vibrating) is about <NUM> to about <NUM>.

Then, the pump <NUM> utilizes a vibration of the vibrating plate <NUM> to change a pressure in the pump chamber <NUM> and convey fluid. The specific operation of the pump <NUM> will be described later.

In outline, the pump <NUM> increases a volume of the pump chamber <NUM> by the displacement of the vibrating plate <NUM> so that a pressure inside the pump chamber <NUM> is made to be lower than a pressure of the outside. Accordingly, the pump <NUM> sucks the fluid into the pump chamber <NUM> via the holes <NUM>, the flow path opening <NUM>, and the hole <NUM>.

On the other hand, the pump <NUM> reduces the volume of the pump chamber <NUM> by the displacement of the vibrating plate <NUM> so that the pressure inside the pump chamber <NUM> is made to be higher than the pressure of the outside. Accordingly, the pump <NUM> discharges the fluid inside the pump chamber <NUM> through the gap <NUM>.

The discharged fluid enters the valve <NUM>. As illustrated in <FIG>, the valve <NUM> includes a first case member <NUM>, a second case member <NUM>, a diaphragm <NUM>, a joint film <NUM>, a reinforcing film <NUM>, and an adhesive member <NUM>. In outline, the first case member <NUM> and the second case member <NUM> form a valve chamber. The first case member <NUM> has a suction port <NUM>, and the suction port <NUM> communicates with the valve chamber. The second case member <NUM> has a discharge port <NUM> and an exhaust port <NUM>, and the discharge port <NUM> and the exhaust port <NUM> communicate with the valve chamber.

The diaphragm <NUM> is joined to the reinforcing film <NUM> by using the joint film <NUM>. The membranous body is disposed in the valve chamber, and divides the valve chamber into a first valve chamber communicating with the suction port <NUM> and a second valve chamber communicating with the discharge port <NUM> and the exhaust port <NUM>. The membranous body is provided with a plurality of holes for realizing a rectifying function.

The adhesive member <NUM> adheres the first case member <NUM>, the second case member <NUM>, and the membranous body.

Such a valve <NUM> is connected to the pump <NUM> with a coupling member <NUM> interposed therebetween. The coupling member <NUM> has a tubular shape and connects the first case member <NUM> and the support plate <NUM>.

In such a configuration, the fluid discharged from the gap <NUM> of the pump <NUM> flows into the valve chamber through the suction port <NUM> of the valve <NUM>. By an inflow of the fluid, the membranous body formed of the diaphragm <NUM>, the joint film <NUM>, and the reinforcing film <NUM> deforms so as to be displaced toward the discharge port <NUM> side, and the suction port <NUM> and the discharge port <NUM> are in a communication state. Therefore, the fluid flowing from the suction port <NUM> is discharged to the outside through the discharge port <NUM>. On the other hand, when the fluid flows in from the discharge port <NUM>, the membranous body formed of the diaphragm <NUM>, the joint film <NUM>, and the reinforcing film <NUM> deforms so as to be displaced toward the suction port <NUM> side, and the suction port <NUM> and the discharge port <NUM> are in a non-communication state. Then, the discharge port <NUM> and the exhaust port <NUM> are in a communication state. Therefore, the fluid flowing from the discharge port <NUM> is discharged to the outside through the exhaust port <NUM>.

In such a configuration, the film valve <NUM> operates (behaves) as follows. <FIG> are enlarged cross-sectional views illustrating operation of the film valve <NUM>. Note that illustration of the displacement of the vibrating plate <NUM> is omitted in <FIG>.

When the vibrating plate <NUM> is displaced and the center of the vibrating plate <NUM> approaches the flow path forming member <NUM>, as illustrated in <FIG>, a central space of the pump chamber <NUM> in a plan view, that is, a space closer to the center than a position where the film valve <NUM> is disposed has a higher pressure (relative high pressure) than an outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, a portion on an outer edge side (a portion on a free end side) of the film valve <NUM> curves toward a vibrating plate <NUM> side, and is in contact with the surface of the vibrating plate <NUM>. As a result, the central space and the outer edge space of the pump chamber <NUM> communicate with each other, and the fluid stored in the central space is conveyed to the outer edge space, and is discharged from the gap <NUM>. At this time, since the film valve <NUM> is in contact with the surface of the vibrating plate <NUM>, the conveyance of the fluid is not hindered and a flow rate is not reduced.

When the vibrating plate <NUM> is displaced and the center of the vibrating plate <NUM> moves away from the flow path forming member <NUM>, as illustrated in <FIG>, the central space of the pump chamber <NUM> in a plan view, that is, the space closer to the center than the position where the film valve <NUM> is disposed has a lower pressure (relative low pressure) than the outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, the portion on the outer edge side (the portion on the free end side) of the film valve <NUM> curves toward a flow path forming member <NUM> side, and is in contact with the surface of the flow path forming member <NUM>. As a result, communication between the central space and the outer edge space of the pump chamber <NUM> is blocked. Therefore, a backflow of the fluid from the outer edge side to the central space is suppressed.

As the vibrating plate <NUM> repeats a vibration, the film valve <NUM> repeats the operation as illustrated in <FIG> is a diagram schematically illustrating the operation of the pump.

A state ST1 indicates a state in which the vibrating plate <NUM> is in a default position in the process of the pump <NUM> sucking the fluid and reaching the discharge. In this case, the film valve <NUM> is in the substantially default state, that is, a state without deformation.

In a state ST2, the central portion of the vibrating plate <NUM> approaches the flow path forming member <NUM> than in the state ST1. In this case, the pressure in the central space becomes high compared to the state ST1 and becomes high relative to the pressure in the outer edge space. As a result, the fluid is pushed out from the central space toward the outer edge. Accordingly, the portion on the outer edge side of the film valve <NUM> also curves toward the vibrating plate <NUM> side.

In a state ST3, the central portion of the vibrating plate <NUM> further approaches the flow path forming member <NUM> with respect to the state ST2. In this case, the central pressure becomes further high compared to the state ST2 and becomes further high relative to the pressure in the outer edge space. As a result, the fluid is further pushed out from the central space towards the outer edge. Accordingly, the portion on the outer edge side of the film valve <NUM> further curves toward the vibrating plate <NUM> side and is in contact with the surface of the vibrating plate <NUM>.

In a state ST4, the central portion of the vibrating plate <NUM> is separated from the flow path forming member <NUM> with respect to the state ST3. In this case, the pressure in the central space becomes low compared to the state ST3, but becomes high relative to the pressure in the outer edge space. As a result, the portion on the outer edge side of the film valve <NUM> is separated from the surface of the vibrating plate <NUM> and approaches the default state.

A state ST5 indicates a state in which the vibrating plate <NUM> is in the default position after the pump <NUM> discharges the fluid. In this case, the film valve <NUM> is in the substantially default state, that is, the state without deformation.

In a state ST6, the central portion of the vibrating plate <NUM> is separated from the flow path forming member <NUM> with respect to the state ST5. In this case, the pressure in the central space becomes low compared to the state ST5 and becomes low relative to the pressure in a flow path including the hole <NUM> and the outer edge space. As a result, the fluid is drawn into the central space via the hole <NUM>. Accordingly, the portion on the outer edge side of the film valve <NUM> curves toward the flow path forming member <NUM> side. The film valve <NUM> suppresses the backflow of the fluid from the outer edge space to the central space.

In a state ST7, the central portion of the vibrating plate <NUM> is separated from the flow path forming member <NUM> with respect to the state ST6. In this case, the central pressure becomes further low compared to the state ST6 and becomes further low relative to the pressure in the flow path including the hole <NUM> and the outer edge space. As a result, the fluid is further drawn into the central space via the hole <NUM>. Accordingly, the portion on the outer edge side of the film valve <NUM> further curves toward the flow path forming member <NUM> side and is in contact with the surface of the flow path forming member <NUM>. As a result, the outer edge space and the central space are separated by the film valve <NUM>, and the backflow of the fluid from the outer edge space to the central space is further effectively suppressed.

In a state ST8, the central portion of the vibrating plate <NUM> approaches the flow path forming member <NUM> with respect to the state ST7. In this case, the pressure in the central space becomes high compared to the state ST7, but becomes low relative to the pressure in the outer edge space. As a result, the portion on the outer edge side of the film valve <NUM> is separated from the surface of the flow path forming member <NUM> and approaches the default state.

Then, the pump <NUM> returns to the state ST1 and the above-described operation is repeated.

As described above, by using the configuration of the pump <NUM>, it is possible to suppress the backflow of fluid through the outer edge space, that is, the gap <NUM>, when the fluid is sucked. Further, when the fluid is conveyed from the central space to the outer edge space, that is, when the fluid is discharged from the gap <NUM>, the film valve <NUM> does not hinder the conveyance of the fluid.

As a result, pump performance of the pump <NUM> is improved. <FIG> is a graph showing a comparison result of P-Q characteristics. In <FIG>, the horizontal axis represents a pressure and the vertical axis represents a flow rate. In <FIG>, the solid line indicates the configuration of the present application, and the broken line indicates a comparative configuration. The comparative configuration is a configuration without the film valve <NUM> described above.

As shown in <FIG>, the P-Q characteristic is improved by using the configuration of the present application (pump <NUM>). That is, the pump characteristics are improved.

Note that, in the above description, a joint position of the film valve <NUM> by the joint member <NUM> may overlap a node position of the vibration of the vibrating plate <NUM>. As a result, it is possible to suppress a stress due to the vibration of the vibrating plate <NUM> being applied to the joint member <NUM>. Therefore, it is possible to suppress peeling off of the film valve <NUM>.

Next, a pump according to a second embodiment of the present invention will be described with reference to the drawings. <FIG> is a cross-sectional view illustrating a configuration of a pump 10A according to the second embodiment of the present invention.

As illustrated in <FIG>, the pump 10A according to the second embodiment is different from the pump <NUM> according to the first embodiment in that a film valve 13A is set on the flow path forming member <NUM>. Further, the pump 10A is different from the pump <NUM> in that a vibrating plate 11A is included. Another configuration of the pump 10A is similar to the configuration of the pump <NUM>, and descriptions of similar portions will be omitted.

A shape of the film valve 13A is similar to the shape of the film valve <NUM> illustrated in the pump <NUM>, and a shape of a joint member 14A is similar to the shape of the joint member <NUM> illustrated in the pump <NUM>.

The film valve 13A is joined to the surface of the flow path forming member <NUM> on the pump chamber <NUM> side by using the joint member 14A. At this time, the film valve 13A is disposed at a position such that the hole <NUM> is in a space surrounded by the outer end of the film valve 13A in a plan view.

A portion of the film valve 13A having a predetermined width on an inner end side of an annular shape is joined to the flow path forming member <NUM> by the joint member 14A, and a portion on an outer end side is not joined. Accordingly, the film valve 13A is joined to the flow path forming member <NUM> in a state where a portion having a predetermined area on the outer end side can vibrate.

The vibrating plate 11A is a flat plate having a constant thickness. Note that the vibrating plate 11A may have a shape similar to the shape of the vibrating plate <NUM> illustrated in the pump <NUM>.

In such a configuration, the film valve 13A operates (behaves) as follows. <FIG> are enlarged cross-sectional views illustrating operation of the film valve 13A. Note that illustration of the displacement of the vibrating plate 11A is omitted in <FIG>.

When the vibrating plate 11A is displaced and the center of the vibrating plate 11A approaches the flow path forming member <NUM>, as illustrated in <FIG>, a central space of the pump chamber <NUM> in a plan view, that is, a space closer to the center than the position where the film valve 13A is disposed has a higher pressure (relative high pressure) than an outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, the portion on an outer edge side (the portion on the free end side) of the film valve 13A curves toward a flow path forming member <NUM> side, and is in contact with the surface of the flow path forming member <NUM>. As a result, the central space and the outer edge space of the pump chamber <NUM> communicate with each other, and fluid stored in the central space is conveyed to the outer edge space, and is discharged from the gap <NUM>. At this time, since the film valve 13A is in contact with the surface of the flow path forming member <NUM>, the conveyance of the fluid is not hindered and a flow rate is not reduced.

When the vibrating plate 11A is displaced and the center of the vibrating plate 11A moves away from the flow path forming member <NUM>, as illustrated in <FIG>, the central space of the pump chamber <NUM> in a plan view, that is, the space closer to the center than the position where the film valve 13A is disposed has a lower pressure (relative low pressure) than the outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, the portion on the outer edge side (the portion on the free end side) of the film valve 13A curves toward the vibrating plate 11A side, and is in contact with the surface of the vibrating plate 11A. As a result, communication between the central space and the outer edge space of the pump chamber <NUM> is blocked. Therefore, a backflow of the fluid from the outer edge side to the central space is suppressed.

With such a configuration, the pump 10A can achieve similar operation and effects to the pump <NUM>.

Further, the flow path forming member <NUM> does not vibrate or hardly vibrates. Therefore, it is possible to suppress a stress due to vibration being applied to the joint member 14A, and it is possible to suppress peeling off of the film valve 13A.

Next, a pump according to a third embodiment of the present invention will be described with reference to the drawing. <FIG> is a cross-sectional view illustrating a configuration of a pump 10B according to the third embodiment of the present invention.

As illustrated in <FIG>, the pump 10B according to the third embodiment is different from the pump <NUM> according to the first embodiment in that a film valve 13B is provided. Another configuration of the pump 10B is similar to the configuration of the pump <NUM>, and descriptions of similar portions will be omitted.

The film valve 13B has a circular shape. The film valve 13B is joined to a surface of the thick portion <NUM> of the vibrating plate <NUM>. At this time, a central portion of the film valve 13B having a predetermined area is joined to the thick portion <NUM>, and a portion on an outer end side is not joined. Accordingly, the film valve 13B is joined to the vibrating plate <NUM> in a state where a portion having a predetermined area on the outer end side can vibrate.

With such a configuration, the pump 10B can achieve similar operation and effects to the pump <NUM>.

Next, a pump according to a fourth embodiment of the present invention will be described with reference to the drawings. <FIG> is a cross-sectional view illustrating a configuration of a pump 10C according to the fourth embodiment of the present invention.

As illustrated in <FIG>, the pump 10C according to the fourth embodiment is different from the pump <NUM> according to the first embodiment in the fixing structure of a film valve 13C. Another configuration of the pump 10C is similar to the configuration of the pump <NUM>, and descriptions of similar portions will be omitted.

The film valve 13C has a configuration similar to the film valve <NUM>. A portion of the film valve 13C having a predetermined width on an outer end side of the annular shape is joined to the vibrating plate <NUM> by a joint member 14C, and a portion on an inner end side is not joined. Accordingly, the film valve 13C is joined to the vibrating plate <NUM> in a state where a portion having a predetermined area on the inner end side can vibrate. The film valve 13C corresponds to a "third film valve" of the present invention.

In such a configuration, the film valve 13C operates (behaves) as follows. <FIG> are enlarged cross-sectional views illustrating operation of the film valve 13C. Note that illustration of the displacement of the vibrating plate <NUM> is omitted in <FIG>.

When the vibrating plate <NUM> is displaced and the center of the vibrating plate <NUM> approaches the flow path forming member <NUM>, as illustrated in <FIG>, a central space of the pump chamber <NUM> in a plan view, that is, a space closer to the center than the position where the film valve 13C is disposed has a higher pressure (relative high pressure) than an outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, the portion on the inner end side (a portion on a free end side) of the film valve 13C curves toward the flow path forming member <NUM>, and is in contact with the surface of the flow path forming member <NUM>. As a result, communication between the central space and the outer edge space of the pump chamber <NUM> is blocked, and fluid stored in the central space is discharged from the hole <NUM>. That is, in the pump 10C, the hole <NUM> serves as a discharge port. At this time, since the film valve 13C is in contact with the surface of the flow path forming member <NUM>, leakage of the fluid from the central space toward the outer end side is suppressed.

When the vibrating plate <NUM> is displaced and the center of the vibrating plate <NUM> moves away from the flow path forming member <NUM>, as illustrated in <FIG>, the central space of the pump chamber <NUM> in a plan view, that is, a space closer to the center than the position where the film valve 13C is disposed has a lower pressure (relative low pressure) than the outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, the portion on the inner end side (the portion on the free end side) of the film valve 13C curves toward the vibrating plate <NUM> side and is in contact with the surface of the vibrating plate <NUM>. As a result, the central space and the outer edge space of the pump chamber <NUM> communicate with each other. Therefore, the fluid is sucked from the gap <NUM> into the central space through the outer edge space. At this time, since the film valve 13C is in contact with the surface of the vibrating plate <NUM>, the conveyance of the fluid is not hindered and a flow rate is not reduced.

As described above, the pump 10C has a configuration in which a suction port and a discharge port are disposed in reverse with respect to the pump <NUM>.

Then, by using the configuration of the pump 10C, it is possible to suppress leakage of the fluid through the outer edge space, that is, the gap <NUM>, when the fluid is discharged. Further, when the fluid is conveyed from the outer edge space to the central space, that is, when the fluid is sucked from the gap <NUM>, the film valve 13C does not hinder the conveyance of the fluid. As a result, pump performance of pump 10C is improved.

Next, a pump according to a fifth embodiment of the present invention will be described with reference to the drawing. <FIG> is an exploded perspective view of a pump 10D according to the fifth embodiment of the present invention.

As illustrated in <FIG>, the pump 10D according to the fifth embodiment is different from the pump <NUM> according to the first embodiment in a shape of a vibrating plate 11D and a shape of a piezoelectric element 12D. Another configuration of the pump 10D is similar to the configuration of the pump <NUM>, and descriptions of similar portions will be omitted.

As illustrated in <FIG>, the vibrating plate 11D has a thin rectangular portion 111D. Further, the piezoelectric element 12D has a rectangular shape.

Even with such a configuration, the pump 10D can obtain similar operation and effects to the pump <NUM>.

Next, a pump according to a sixth embodiment of the present invention will be described with reference to the drawings. <FIG> is a cross-sectional view illustrating a configuration of a pump 10E according to the sixth embodiment of the present invention.

As illustrated in <FIG>, the pump 10E according to the sixth embodiment is different from the pump <NUM> according to the first embodiment in that a film valve <NUM> and a joint member <NUM> are added. Another configuration of the pump 10E is similar to the configuration of the pump <NUM>, and descriptions of similar portions will be omitted.

The pump 10E includes the film valve <NUM> and the joint member <NUM>.

The film valve <NUM> is disposed at on a center side relative to the film valve <NUM> in a plan view. The film valve <NUM> is circular and has a through-hole in the center.

The film valve <NUM> is joined to the flow path forming member <NUM> with the joint member <NUM> interposed therebetween in a state where the through-hole overlaps the hole <NUM>. At this time, a portion of the film valve <NUM> having a predetermined width on an inner end side that is in contact with the through-hole is joined to the flow path forming member <NUM> by the joint member <NUM>, and a portion on an outer end side is not joined. Accordingly, the film valve <NUM> is joined to the flow path forming member <NUM> in a state where a portion having a predetermined area on the outer end side can vibrate. The film valve <NUM> corresponds to a "second film valve" of the present invention.

As described above, in the pump 10E, the film valve <NUM> and the film valve <NUM> have the same positional relationship between a fixed end portion (an end portion fixed by the joint member) and a free end (an end portion not fixed by the joint member) in a direction connecting the center and an outer edge.

In such a configuration, the film valve <NUM> operates (behaves) as follows. <FIG> are enlarged cross-sectional views illustrating operation of the film valves. Note that illustration of the displacement of the vibrating plate <NUM> is omitted in <FIG>.

In this case, as illustrated in <FIG>, a portion on an outer edge side (a portion on a free end side) of the film valve <NUM> curves toward the vibrating plate <NUM> side, and is in contact with the surface of the vibrating plate <NUM>. As a result, the central space and the outer edge space of the pump chamber <NUM> communicate with each other, and fluid stored in the central space is conveyed to the outer edge space, and is discharged from the gap <NUM>. At this time, since the film valve <NUM> is in contact with the surface of the vibrating plate <NUM>, the conveyance of the fluid is not hindered and a flow rate is not reduced.

Further, as illustrated in <FIG>, a portion on an outer edge side (the portion on the free end side) of the film valve <NUM> curves toward the vibrating plate <NUM> side, and is in contact with the surface of the vibrating plate <NUM>. As a result, communication between the central space and the hole <NUM> of the pump chamber <NUM> is blocked, and leakage of the fluid stored in the central space from the hole <NUM> is suppressed. This allows the fluid to be discharged more efficiently.

When the vibrating plate <NUM> is displaced and the center of the vibrating plate <NUM> moves away from the flow path forming member <NUM>, as illustrated in <FIG>, the central space of the pump chamber <NUM> in a plan view, that is, the space closer to the center than a position where the film valve <NUM> is disposed has a lower pressure (relative low pressure) than the outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, the portion on the outer edge side (the portion on the free end side) of the film valve <NUM> curves toward the flow path forming member <NUM> side, and is in contact with the surface of the flow path forming member <NUM>. As a result, communication between the central space and the outer edge space of the pump chamber <NUM> is blocked. Therefore, a backflow of the fluid from the outer edge side to the central space is suppressed.

Further, as illustrated in <FIG>, the portion on the outer edge side (the portion on the free end side) of the film valve <NUM> curves toward the flow path forming member <NUM> side, and is in contact with the surface of the flow path forming member <NUM>. As a result, the central space of the pump chamber <NUM> and the hole <NUM> communicate with each other, and the fluid is sucked into the central space from the hole <NUM>. As described above, the film valve <NUM> does not hinder the suction of the fluid from the hole <NUM>.

Next, a pump according to a seventh embodiment of the present invention will be described with reference to the drawings. <FIG> is a cross-sectional view illustrating a configuration of a pump 10F according to the seventh embodiment of the present invention.

As illustrated in <FIG>, the pump 10F according to the seventh embodiment is different from the pump 10C according to the fourth embodiment in that a film valve 131C and a joint member 141C are added. Another configuration of the pump 10F is similar to the configuration of the pump 10C, and descriptions of similar portions will be omitted.

The pump 10F includes the film valve 131C and the joint member 141C.

The film valve 131C is disposed on a center side relative to the film valve 13C in a plan view. The film valve 131C is circular and has a through-hole in the center.

The film valve 131C is joined to the flow path forming member <NUM> with the joint member 141C interposed therebetween in a state where the through-hole overlaps the hole <NUM>. At this time, a portion of the film valve 131C having a predetermined width on an outer end side is joined to the flow path forming member <NUM> by the joint member 141C, and a portion on an inner end side is not joined. Accordingly, the film valve 131C is joined to the flow path forming member <NUM> in a state where a portion having a predetermined area on the inner end side can vibrate. The film valve 131C corresponds to a "fourth film valve" of the present invention.

As described above, in the pump 10F, the film valve 13C and the film valve 131C have the same positional relationship between a fixed end portion (an end portion fixed by the joint member) and a free end (an end portion not fixed by the joint member) in a direction connecting the center and an outer edge.

In such a configuration, the film valve 13C operates (behaves) as follows. <FIG> are enlarged cross-sectional views illustrating operation of the film valves. Note that illustration of the displacement of the vibrating plate <NUM> is omitted in <FIG>.

When the vibrating plate <NUM> is displaced and the center of the vibrating plate <NUM> approaches the flow path forming member <NUM>, as illustrated in <FIG>, a central space of the pump chamber <NUM> in a plan view, that is, a space closer to the center than a position where the film valve 13C is disposed has a higher pressure (relative high pressure) than an outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, a portion on an inner end side (a portion on a free end side) of the film valve 13C curves toward the flow path forming member <NUM>, and is in contact with the surface of the flow path forming member <NUM>. As a result, communication between the central space and the outer edge space of the pump chamber <NUM> is blocked, and fluid stored in the central space is discharged from the hole <NUM>. That is, in the pump 10E, the hole <NUM> serves as a discharge port. At this time, since the film valve 13C is in contact with the surface of the flow path forming member <NUM>, leakage of the fluid from the central space toward the outer end side is suppressed.

Further, as illustrated in <FIG>, a portion on an inner end side (the portion on the free end side) of the film valve 131C curves toward a flow path forming member <NUM> side, and is in contact with the surface of the flow path forming member <NUM>. As a result, the central space of the pump chamber <NUM> and the hole <NUM> communicate with each other, and the fluid stored in the central space is discharged from the hole <NUM>. At this time, since the film valve 131C is in contact with the surface of the flow path forming member <NUM>, the discharge of the fluid is not hindered and a flow rate is not reduced.

When the vibrating plate <NUM> is displaced and the center of the vibrating plate <NUM> moves away from the flow path forming member <NUM>, as illustrated in <FIG>, the central space of the pump chamber <NUM> in a plan view, that is, the space closer to the center than the position where the film valve 13C is disposed has a lower pressure (relative low pressure) than the outer edge space of the pump chamber <NUM>.

In this case, as illustrated in <FIG>, the portion on the inner end side (the portion on the free end side) of the film valve 13C curves toward the vibrating plate <NUM> side and is in contact with the surface of the vibrating plate <NUM>. As a result, the central space and the outer edge space of the pump chamber <NUM> communicate with each other. Therefore, the fluid is sucked from the gap <NUM> into the central space through the outer edge space. At this time, since the film valve 13C is in contact with the surface of the vibrating plate <NUM>, the conveyance of the fluid is not hindered and the flow rate is not reduced.

Further, as illustrated in <FIG>, the portion on the inner end side (the portion on the free end side) of the film valve 131C curves toward the vibrating plate <NUM> side, and is in contact with the surface of the vibrating plate <NUM>. As a result, communication between the central space and the hole <NUM> of the pump chamber <NUM> is blocked, and a backflow of the fluid from the hole <NUM> to the central space is suppressed.

Next, a pump according to an eighth embodiment of the present invention will be described with reference to the drawing. <FIG> is a cross-sectional view illustrating a configuration of a pump <NUM> according to the eighth embodiment of the present invention. Note that, in <FIG>, only the minimum necessary configuration is described as a pump, and descriptions of the other parts are omitted.

As illustrated in <FIG>, the pump <NUM> according to the eighth embodiment is different from the pump <NUM> according to the first embodiment in a vibrating plate <NUM>, a film valve <NUM>, and a joint member <NUM>. Another configuration of the pump <NUM> is similar to the configuration of the pump <NUM>, and descriptions of similar portions will be omitted.

As illustrated in <FIG>, the pump <NUM> has a wall <NUM> on one principal surface in the vibrating plate <NUM>. The wall <NUM> has a shape protruding from the one principal surface of the vibrating plate <NUM> toward the flow path forming member <NUM> side (pump chamber <NUM> side), and has an annular shape in a plan view.

In a plan view of the pump <NUM>, an inner space surrounded by the wall <NUM> overlaps the hole <NUM> of the flow path forming member <NUM>.

The film valve <NUM> has a circular shape in a plan view. A central portion of the film valve <NUM> is located in a central cavity formed by the wall <NUM>. Then, the central portion of the film valve <NUM> is joined to the one principal surface of the vibrating plate <NUM> by the joint member <NUM>.

With this configuration, the film valve <NUM> is fixed to the vibrating plate <NUM> so that a portion on the outer end side can be deformed. Therefore, the pump <NUM> can achieve similar operation and effects to the pump <NUM> according to the first embodiment.

Next, a pump according to a ninth embodiment of the present invention will be described with reference to the drawings. <FIG> is a cross-sectional view illustrating a configuration of a pump <NUM> according to the ninth embodiment of the present invention. Note that, in <FIG>, only the minimum necessary configuration is described as a pump, and descriptions of the other parts are omitted.

As illustrated in <FIG>, the pump <NUM> according to the ninth embodiment is different from the pump 10C according to the fourth embodiment in an arrangement aspect of a film valve <NUM> with respect to a vibrating plate <NUM> and a shape of a flow path forming member <NUM>. Another configuration of the pump <NUM> is similar to the configuration of the pump 10E, and descriptions of similar portions will be omitted.

The pump <NUM> includes the vibrating plate <NUM>, the piezoelectric element <NUM>, the film valve <NUM>, a joint member <NUM>, the flow path forming member <NUM>, and the side wall member <NUM>.

<FIG> is a plan view of the vibrating plate <NUM> of the pump <NUM> according to the ninth embodiment of the present invention. As illustrated in <FIG>, the vibrating plate <NUM> has a disk shape in a plan view. The vibrating plate <NUM> has a constant thickness. The support plate <NUM> is disposed on an outer periphery of the vibrating plate <NUM> so as to be separated from the vibrating plate <NUM>. The support plate <NUM> has, for example, a rectangular shape in a plan view. The vibrating plate <NUM> and the support plate <NUM> are connected by the plurality of support members <NUM>. The support member <NUM> includes a first beam portion <NUM>, second beam portions <NUM>, and a third beam portion <NUM>. The first beam portion <NUM> is connected to an outer edge of the vibrating plate <NUM> and is not connected to the support plate <NUM>. The second beam portion <NUM> is connected to the support plate <NUM> and is not connected to the outer edge of the vibrating plate <NUM>. The two second beam portions <NUM> are disposed in a direction along the outer edge of the vibrating plate <NUM> with the first beam portion <NUM> interposed therebetween. The third beam portion <NUM> has a shape extending in the direction along the outer edge of the vibrating plate <NUM>, and connects the first beam portion <NUM> and the two second beam portions <NUM>. Thus, the support member <NUM> is a beam that supports the vibrating plate <NUM> for the support plate <NUM>. The three support members <NUM> are formed, and the three support members <NUM> are spaced apart from one another in the direction along the outer edge of the vibrating plate <NUM>. For example, in an example of <FIG>, the three support members <NUM> are disposed so as to form an angle of <NUM>° with the center of the vibrating plate <NUM> as a reference point.

Then, a portion where the support members <NUM> are not formed between the vibrating plate <NUM> and the support plate <NUM> is the gap <NUM>.

As an example, the dimensions of each member are as follows. The circular vibrating plate <NUM> has a thickness of <NUM> and a diameter φ of <NUM>. The circular piezoelectric element <NUM> has a thickness of <NUM> and a diameter of <NUM>. A boundary portion between a portion where the vibrating plate <NUM> and the film valve <NUM> are joined and a deformable portion is located at a position of <NUM> from the center of the pump chamber <NUM>. The vibrating plate <NUM> vibrates at a frequency of <NUM>. Alternatively, when the thickness of the vibrating plate <NUM> is <NUM> and the other dimensions are not changed, the vibrating plate vibrates at a frequency of <NUM>.

With such a configuration, the support member <NUM> has higher flexibility than the vibrating plate <NUM>. Therefore, the force with which the support member <NUM> restrains the vibrating plate <NUM> is weak. Accordingly, the vibrating plate <NUM> can vibrate with large displacement. With this configuration, the vibrating plate <NUM> has an antinode at the center, has a node at an intermediate position from the center to the outer edge, and has an antinode at the outer edge or in the vicinity thereof, which enables resonance vibration represented by the Bessel function of the first kind. Here, a portion formed of the vibrating plate <NUM>, the support plate <NUM>, and the support member <NUM> corresponds to a "flat plate-shaped member" of the present invention, and the gap <NUM> corresponds to a "third vent hole" of the present invention.

The piezoelectric element <NUM> is disposed on one principal surface of the vibrating plate <NUM>.

The film valve <NUM> is made of a flexible material. The film valve <NUM> has an annular shape. The film valve <NUM> is disposed in the vicinity of the outer edge of the vibrating plate <NUM>. Note that the film valve <NUM> may be disposed on an outer edge side relative to the vibration node of the vibrating plate <NUM>, and is preferably close to the antinode at the outer edge. This film valve <NUM> corresponds to a "fifth film valve" of the present invention.

The film valve <NUM> is joined to the vibrating plate <NUM> by the annular-shaped joint member <NUM>. At this time, the film valve <NUM> is joined so that a central portion can be deformed.

The flow path forming member <NUM> is a plate-shaped member. The flow path forming member <NUM> has an annular-shaped protruding portion <NUM>. In a plan view, at least a part of the annular-shaped protruding portion <NUM> overlaps the film valve <NUM>. The center of the protruding portion <NUM> and the center of the film valve <NUM> substantially coincide with each other.

The flow path forming member <NUM> is disposed such that a surface formed by the protruding portion <NUM> faces the vibrating plate <NUM>.

The flow path forming member <NUM> has a plurality of holes <NUM>. The plurality of holes <NUM> penetrate through the flow path forming member <NUM> in a thickness direction. The plurality of holes <NUM> are disposed so as to be spaced apart from each other in the circumferential direction. Preferably, the plurality of holes <NUM> overlap the node of the vibration of the vibrating plate <NUM>. The plurality of holes <NUM> correspond to a "fourth vent hole" of the present invention.

With this configuration, the pump <NUM> has the pump chamber <NUM> that is a hollow space surrounded by the vibrating plate <NUM>, the support plate <NUM>, the flow path forming member <NUM>, and the side wall member <NUM>. The film valve <NUM> is disposed in the pump chamber <NUM>. Further, the pump chamber <NUM> communicates with the holes <NUM> and also with the gap <NUM>.

The pump <NUM> having such a configuration behaves as illustrated in <FIG> to repeat suction and discharge of fluid. <FIG> is a side cross-sectional view illustrating a state of the pump <NUM> when fluid is discharged, and <FIG> is a side cross-sectional view illustrating a state of the pump <NUM> when the fluid is sucked.

As described above, when the vibrating plate <NUM> generates the vibration represented by the Bessel function of the first kind, change in volume of the pump chamber <NUM> due to the vibration of the vibrating plate <NUM> becomes larger in an outer edge space than in a central space. That is, the change in volume outside the vibration node becomes larger than the change in volume inside the vibration node.

Therefore, as illustrated in <FIG>, when the antinode at the center of the vibrating plate <NUM> moves away from the flow path forming member <NUM> and the antinode on the outer edge side approaches the flow path forming member <NUM>, the pump chamber <NUM> decreases in volume and becomes a positive pressure. Therefore, the fluid in the pump chamber <NUM> is discharged from the holes <NUM>. At this time, the film valve <NUM> disposed in the vicinity of the antinode on the outer edge side is in contact with the surface of the protruding portion <NUM> of the flow path forming member <NUM>. Therefore, it is possible to suppress a backflow of the fluid in the pump chamber <NUM> to the gap <NUM> on the outer edge side.

On the other hand, as illustrated in <FIG>, when the antinode at the center of the vibrating plate <NUM> approaches the flow path forming member <NUM> and the antinode on the outer edge side moves away from the flow path forming member <NUM>, the pump chamber <NUM> expands in volume and becomes a negative pressure. Thus, the fluid flows into the pump chamber <NUM> from the gap <NUM>. At this time, a distance between the flow path forming member <NUM> and the vibrating plate <NUM> increases, so that a flow path becomes large and the film valve <NUM> largely separates from the flow path forming member <NUM>. Accordingly, it is possible to suppress a decrease in flow rate of the fluid flowing from the gap <NUM>.

Further, in the pump <NUM>, the plurality of holes <NUM> overlap the node of the vibration of the vibrating plate <NUM> (pressure fluctuation). For this reason, the pressure difference between the inside and the outside of the pump chamber <NUM> is not large. Therefore, the flow rate of the fluid flowing into the pump chamber <NUM> from the gap <NUM> and the flow rate of the fluid discharged from the holes <NUM> become substantially equal, and a backflow through the holes <NUM> can be suppressed without using a check valve.

In addition, in the pump <NUM>, since the protruding portion <NUM> and the film valve <NUM> overlap each other in a plan view, a distance between the film valve <NUM> and the protruding portion <NUM> when not operating can be shortened, and sealing of the flow path by the film valve <NUM> can be quickly performed.

Next, a pump according to a 10th embodiment of the present invention will be described with reference to the drawing. <FIG> is a cross-sectional view illustrating a configuration of a pump 10I according to the 10th embodiment of the present invention. Note that, in <FIG>, only the minimum necessary configuration is described as the pump, and descriptions of the other parts are omitted.

As illustrated in <FIG>, the pump 10I according to the tenth embodiment is different from the pump <NUM> according to the ninth embodiment in configurations of a hole 151I and a check valve <NUM>. Note that a vibrating plate 11I is similar to the vibrating plate <NUM>, a film valve 13I is similar to the film valve <NUM>, and a joint member 14I is similar to the joint member <NUM>. In addition, a flow path forming member 15I is similar to the flow path forming member <NUM> except that the flow path forming member 15I has the hole 151I and does not have the holes <NUM>.

The pump 10I includes the flow path forming member 15I. The flow path forming member 15I has the hole 151I. The hole 151I penetrates through the flow path forming member 15I in a thickness direction. The hole 151I is disposed at the center of the flow path forming member 15I.

The check valve <NUM> is disposed in the hole 151I, permits a flow of fluid from the pump chamber <NUM> to the outside, and blocks a flow of the fluid from the outside to the pump chamber <NUM>.

Even with such a configuration, the pump 10I can obtain similar operation and effects to the pump <NUM>.

Next, a pump according to an 11th embodiment of the present invention will be described with reference to the drawing. <FIG> is a cross-sectional view illustrating a configuration of a pump 10J according to the 11th embodiment of the present invention. Note that, in <FIG>, only the minimum necessary configuration is described as a pump, and descriptions of the other parts are omitted.

As illustrated in <FIG>, the pump 10J according to the eleventh embodiment is different from the pump <NUM> according to the ninth embodiment in positions where holes 151J are formed in a flow path forming member 15J, a support member 115J, and holes 117J. Note that a film valve 13J is similar to the film valve <NUM>, and a joint member 14J is similar to the joint member <NUM>. The flow path forming member 15J is similar to the flow path forming member <NUM> except that the flow path forming member 15J has the holes 151J and does not have the holes <NUM>.

The vibrating plate 11J includes the plurality of holes 117J. The plurality of holes 117J penetrate through the vibrating plate 11J in a thickness direction. The plurality of holes 117J are disposed so as to be spaced apart from one another in a circumferential direction. Preferably, the plurality of holes 117J overlap a node of a vibration of the vibrating plate 11J. The plurality of holes 117J correspond to the "third vent hole" of the present invention.

The support member 115J is formed of a resin film containing polyimide, liquid crystal polymer, PET, or the like as a main material, has elasticity, and has no gap.

By using such a material, the support member 115J has a low elastic modulus, and thus is more flexible than the vibrating plate 11J. Therefore, since the support member 115J has a weak force to restrain the vibrating plate 11J, the vibrating plate 11J can vibrate with large displacement.

The flow path forming member 15J has a plurality of holes 151J. The plurality of holes 151J are disposed so as to be spaced apart from one another in the circumferential direction. The plurality of holes 151J are disposed on an outer edge side relative to the protruding portion <NUM>. The plurality of holes 151J correspond to the "fourth vent hole" of the present invention.

Even with such a configuration, the pump 10J can obtain similar operation and effects to the pump <NUM>.

Note that, in the 11th embodiment, even when the support member 115J is made of the same material as the vibrating plate 11J, when the thickness of the support member 115J is thinner than the thickness of the vibrating plate 11J, the flexibility of the support member becomes higher than the flexibility of the vibrating plate 11J, and therefore, similar operation and effects can be obtained.

In the ninth to eleventh embodiments, the fifth film valves <NUM>, 13I, and 13J are configured to suppress the discharge of fluid from the central space to the outer edge space of the pump chamber and suck the fluid from the outer edge space to the central space. However, conversely, it may be configured such that the suction of the fluid from the outer edge space to the central space of the pump chamber is suppressed, and the fluid is discharged from the central space to the outer edge space. In this case, the film valve is in contact with or separates by the fluid passing through the inside and the outside of a film valve to open and close a flow path.

Next, a pump 10J1 according to a first modification of the eleventh embodiment of the present invention will be described with reference to the drawing. <FIG> is a cross-sectional view illustrating a configuration of the pump 10J1 according to the first modification of the eleventh embodiment of the present invention. Note that, in <FIG>, only the minimum necessary configuration is described as a pump, and descriptions of the other parts are omitted.

As illustrated in <FIG>, the holes 117J are formed in the flow path forming member 15J. Preferably, the plurality of holes 117J overlap the node of a vibration of the vibrating plate 11J. However, the holes 117J may be formed in the vicinity of the center of the flow path forming member 15J.

Further, the plurality of holes 117J are formed in the flow path forming member 15J, but only the one hole 117J may be formed.

In the configuration of <FIG>, the holes 117J and 151J are formed on the same surface. That is, a complicated mechanism is required to shield the pump 10J1. However, by providing the configuration illustrated in <FIG>, similar effects to the pump 10J illustrated in <FIG> are obtained.

Next, a pump 10J2 according to a second modification of the eleventh embodiment of the present invention will be described with reference to the drawings. <FIG> is a cross-sectional view illustrating a configuration of the pump 10J2 according to the second modification of the eleventh embodiment of the present invention. <FIG> is an enlarged cross-sectional view illustrating a joint portion of the support member, the piezoelectric element, and the vibrating plate according to the second modification of the eleventh embodiment of the present invention. Note that, in <FIG>, only the minimum necessary configuration is described as a pump, and descriptions of the other parts are omitted.

As illustrated in <FIG>, the holes 117J may be formed in the flow path forming member 15J, and the support member 115J may be a configuration which has a conductive path to the piezoelectric element <NUM>. Even with this configuration, similar operation and effects to the operation and effects in <FIG> are obtained.

<FIG> is the enlarged cross-sectional view for disclosing the joint portion of the support member, the piezoelectric element, and the vibrating plate in the configuration in <FIG>.

A support member 115JA is formed of a substrate <NUM> having an insulating property, a conductor pattern <NUM>, and a conductor pattern <NUM>. The conductor pattern <NUM> is formed on one principal surface of the substrate <NUM>, and the conductor pattern <NUM> is formed on another principal surface of the substrate <NUM>. Note that the conductor pattern <NUM> and the conductor pattern <NUM> may have any shape as long as both the conductor patterns are insulated from each other. For example, a structure may be such that the entire surface of the substrate <NUM> is covered or a part of the substrate <NUM> is exposed.

The piezoelectric element <NUM> is formed of a piezoelectric body 12P, a driving electrode 12D1, and a driving electrode 12D2. The driving electrode 12D1 is mainly formed on one principal surface of the piezoelectric body 12P, and a part thereof extends to another principal surface through a side surface of the piezoelectric body 12P. The driving electrode 12D2 is formed on another principal surface of the piezoelectric body 12P, and is spaced apart from the driving electrode 12D1.

The conductor pattern <NUM> is in contact with and connected to the driving electrode 12D1 formed on another principal surface of the piezoelectric body 12P. The conductor pattern <NUM> is in contact with the conductive vibrating plate 11J and is connected to the driving electrode 12D2 of the piezoelectric element <NUM> via the vibrating plate 11J.

Note that, in each of the above-described embodiments, the aspect in which one flat film-shaped film valve is used is described, but the film valve may have a configuration as illustrated in <FIG>.

<FIG> is a perspective view illustrating an example of a derivative of the film valve. As illustrated in <FIG>, the film valve <NUM> has an annular shape and has a plurality of slits SL. Each of the plurality of slits SL has a shape extending in a radiation direction of the film valve <NUM>. Each of the plurality of slits SL reaches the outer end of the film valve <NUM>, but does not reach the inner end of the film valve <NUM>. Even such a configuration can be applied to the pump having the aspect in which the inner end side described above is fixed.

Note that, although not illustrated, the pump having the aspect in which the outer end side is fixed may have a shape such that the plurality of slits SL reach the inner end of the film valve <NUM> and does not reach the outer end of the film valve <NUM>.

Further, the film valve <NUM> may have an aspect in which a plurality of fan-shaped films partially overlap one another and are disposed over the entire circumference.

<FIG> is a cross-sectional view illustrating a configuration of a pump <NUM> according to a modification of the first embodiment of the present invention. The pump <NUM> is different from the pump <NUM> according to the first embodiment in that coating agents <NUM> are applied. Another configuration of the pump <NUM> is similar to the configuration of the pump <NUM>, and descriptions of similar portions will be omitted.

As illustrated in <FIG>, the coating agents <NUM> are applied to a portion facing a movable range of the film valve <NUM>. More specifically, the coating agents <NUM> are applied to one principal surface of the flow path forming member <NUM> and one principal surface of the thin portion <NUM> of the vibrating plate <NUM> so as to face the movable range of the film valve <NUM>.

With this configuration, damage caused by the film valve <NUM> coming into contact with the flow path forming member <NUM> or the thin portion <NUM> of the vibrating plate <NUM> can be suppressed.

Note that a main component of the coating agent <NUM> may be resin having a Young's modulus value lower than Young's modulus values of the flow path forming member <NUM> and the thin portion <NUM> of the vibrating plate <NUM>, such as silicone rubber, PTFE or the like. Since these coating agents have low Young's modulus values, impact when the film valve is in contact with the flow path forming member <NUM> or the thin portion <NUM> of the vibrating plate <NUM> can be mitigated. Thereby suppressing the damage to the film valve <NUM>.

Note that it is more preferable that the coating agent <NUM> contain fluorine or molybdenum disulfide as a main component. Since the surfaces of these coating agents have lubricity, the damage due to friction of the film valve <NUM> with the flow path forming member <NUM> or the thin portion <NUM> of the vibrating plate <NUM> can be suppressed.

Similar effects are also obtained when the coating agent <NUM> is applied to one of the flow path forming member <NUM> and the thin portion <NUM> of the vibrating plate <NUM>.

Claim 1:
A pump comprising:
a flat plate-shaped member including:
a vibrating plate (<NUM>) in which a piezoelectric element (<NUM>) is disposed on one principal surface,
a support plate (<NUM>), and
a support member (<NUM>) that connects an outer edge of the vibrating plate (<NUM>) and the support plate (<NUM>) and supports the vibrating plate (<NUM>) so that the vibrating plate (<NUM>) is configured to vibrate in a principal surface direction;
a flow path forming member (<NUM>) disposed so as to face the flat plate-shaped member;
a pump chamber (<NUM>) formed to be surrounded by the flat plate-shaped member, the flow path forming member (<NUM>), and a side wall member (<NUM>) connected to the flat plate-shaped member and the flow path forming member (<NUM>);
an annular film valve (<NUM>) fixed to the flat plate-shaped member or the flow path forming member (<NUM>) and disposed in the pump chamber (<NUM>) so as to overlap the vibrating plate (<NUM>) in a plan view;
a vent hole (<NUM>) formed in the flat plate-shaped member or the flow path forming member (<NUM>); and
a further vent hole (<NUM>) formed in the flow path forming member (<NUM>), wherein
the vent hole (<NUM>) in the flat plate-shaped member or in the flow path forming member (<NUM>) and the further vent hole (<NUM>) in the flow path forming member (<NUM>) are disposed at positions where the annular film valve (<NUM>) is placed therebetween in a plan view, and
the annular film valve (<NUM>) changes a flow path resistance between the vent hole (<NUM>) in the flat plate-shaped member or in the flow path forming member (<NUM>) and the further vent hole (<NUM>) in the flow path forming member (<NUM>) in accordance with a vibration of the vibrating plate (<NUM>),
wherein an opening of the annular film valve (<NUM>) overlaps said further vent hole in the flow path forming forming member in a plan view.