JP2002039074A - Piezoelectric diaphragm pump and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high discharge piezoelectric diaphragm pump by increasing a curving displacement of a diaphragm, which has been a potential cause for damaged polarization effect of a piezoelectric material used in a conventional piezoelectric diaphragm pump, and also to provide a manufacturing method of the high discharge piezoelectric diaphragm pump. SOLUTION: The piezoelectric diaphragm pump has the diaphragm 1 formed by the piezoelectric material 2 and an elastic plate 3, the diaphragm being placed on a boxed-shaped body 4 in which flow passages are formed, wherein a fluid is sucked and discharged through the curving displacement of the diaphragm. On the polarized piezoelectric material 2, an electric field is applied along a polarization direction of the piezoelectric material 2, so that the diaphragm 1 forms the curving displacement, projecting to a direction opposite to the box-shaped body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a piezoelectric diaphragm pump and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 19 and 20, a piezoelectric diaphragm pump used as a drive source of a sphygmomanometer has a diaphragm 1 'made up of a piezoelectric material 2 and an elastic plate 3, and a suction passage 5'. In addition, there is known a device which is mounted on a housing 4 having a discharge channel 6 formed therein, and applies an electric field to the polarized piezoelectric material 2 to bend and deform the diaphragm 1 ′ to perform intake and exhaust of fluid. Have been. The structure of the piezoelectric diaphragm pump will be described in detail. The diaphragm 1 'is composed of a piezoelectric material 2 having an elastic plate 3 also serving as an electrode adhered to the lower surface and a film electrode 14 adhered to the upper surface. The housing 4 is formed by integrating a film-like valve 7 between an upper housing 4a and a lower housing 4b, and the diaphragm 1 'is so arranged that the elastic plate 3 comes into contact with the housing 4. Is disposed on the housing 4, and the outer peripheral edge of the diaphragm 1 ′ is
Are fixed with an adhesive (not shown) to form a piezoelectric diaphragm pump. In addition, FIG.
As shown in (c), an inflow valve chamber 7 provided with an inflow valve is arranged in the suction flow path 5 in the housing 4, and a discharge valve chamber 8 provided with a discharge valve is arranged in the discharge flow path 6. Is what it is.

The piezoelectric diaphragm pump functions as a pump by applying an electric field to the polarized piezoelectric material 2 so that the piezoelectric material 2 expands and contracts and the diaphragm 1 'bends. More specifically, the piezoelectric material 2 is formed as shown in FIG.
As shown in FIG. 5, when an electric field is applied in the same direction as the polarization direction of the piezoelectric material 2 (arrow a) (arrow b), the piezoelectric material 2 contracts in the radial direction (arrow c) as shown in FIG. ) [Fig.
As shown in FIG. 5A, the piezoelectric material 2 extends in the axial direction of the piezoelectric material 2 (arrow c)]. On the other hand, when an electric field is applied in the direction opposite to the polarization direction of the piezoelectric material 2, the piezoelectric material 2 expands in the radial direction of the piezoelectric material 2 (shrinks in the axial direction of the piezoelectric material 2). The diaphragm 1 'has an elastic plate 3 also serving as an electrode adhered to the lower surface of the piezoelectric material 2. When the piezoelectric material 2 is deformed and deformed as described above, the diaphragm 1' is moved as follows. It bends and deforms. For example, as shown in FIG. 26A, when an electric field is applied to the piezoelectric material 2 in the same direction as the polarization direction of the piezoelectric material 2 (arrow a) (arrow b), the piezoelectric material 2 expands in the radial direction (arrow b). As shown in arrow c) and FIG. 23A, the elastic plate 3 restrains the piezoelectric material 2 from expanding in the radial direction (arrow d). As a result, as shown in FIG. 'Is bent upward and bent. On the other hand, as shown in FIG. 26B, when an electric field is applied to the piezoelectric material 2 in the direction opposite to the polarization direction of the piezoelectric material 2 (arrow a) (arrow b), FIG.
The piezoelectric material 2 shrinks in the radial direction (arrow c) as shown in FIG.
The elastic plate 3 restrains the piezoelectric material 2 from shrinking in the radial direction (arrow d). As a result, as shown in FIG. 24B, the diaphragm 1 ′ is positioned along the housing 4 without any gap. become.

[0004] As described above, the diaphragm 1 'is provided between the diaphragm 1' and the housing 4 by being bent upward in a convex shape or by being positioned along the housing 4 without any gap. The capacity of the chamber 13 is changed so that the atmosphere flows into the chamber 13 or the atmosphere is exhausted from the chamber 13. By performing this operation continuously, the piezoelectric diaphragm pump performs a pump operation.

FIG. 21 (a) shows a state in which the diaphragm 1 'is bent upward and convex, the capacity of the chamber 13 is increased, and the atmosphere is sucked into the chamber 13 in the above state. However, at this time, the inflow valve chamber 8
21 (b), the inflowing air pushes up the membrane valve 7 to open the inflow valve and close the exhaust valve of the exhaust valve chamber 9. In addition, FIG.
(A) shows that the diaphragm 1 ′ is located along the housing 4 without any gap and the capacity of the chamber 13 is lost.
At this time, the air discharged from the chamber 13 in the discharge valve chamber 9 pushes down the membrane valve 7 to open the discharge valve in the discharge valve chamber 9 as shown in FIG. And the inflow valve of the inflow valve chamber 8 is closed. As described above, the piezoelectric diaphragm pump has a structure in which air flows in from the inflow passage 5 and discharges air from the discharge passage 6.

[0006]

Here, in order to increase the output of the piezoelectric diaphragm pump, it is conceivable to increase the amount of bending deformation of the diaphragm 1 'so as to increase the capacity of the chamber 13. The amount of bending deformation of the diaphragm 1 ′ depends on the amount of strain deformation of the piezoelectric material 2, but the amount of strain deformation of the piezoelectric material 2 shown in FIG.
From the graph showing the relationship between the magnitude of the electric field applied to the piezoelectric material 2 and the piezoelectric material 2,
It can be understood that the countermeasures should be taken by increasing the intensity of the electric field applied to the.

However, in this piezoelectric diaphragm pump, an electric field is applied in a direction opposite to the polarization direction of the piezoelectric material 2 to promote an increase in strain deformation of the piezoelectric material 2. As shown in the figure, when an electric field is applied in a direction opposite to the polarization direction of the piezoelectric material 2, the intensity of the electric field is increased. It was confirmed that the direction was reversed or the polarization direction in the piezoelectric material 2 was not constant, and the amount of bending deformation of the diaphragm 1 'could not be increased. That is, in this piezoelectric diaphragm pump, even if the intensity of the electric field applied to the diaphragm 1 'is improved, the pump output does not exceed a certain fixed output.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a conventional piezoelectric diaphragm pump increases the amount of flexural displacement of a diaphragm, which may break the polarization of a piezoelectric material, thereby providing a high-output piezoelectric diaphragm. An object of the present invention is to provide a pump and a method for manufacturing the pump.

[0009]

According to a first aspect of the present invention, there is provided a piezoelectric diaphragm pump, comprising:
In a piezoelectric diaphragm pump in which a diaphragm 1 is formed by a piezoelectric material 2 and an elastic plate 3, the above-mentioned diaphragm 1 is installed on a housing 4 in which a flow path is formed, and a fluid is sucked and discharged by bending displacement of the diaphragm 1. Polarized piezoelectric material 2
By applying an electric field in the same direction as the polarization direction of the piezoelectric material 2, the diaphragm 1 is bent upward and convexly on the side opposite to the housing 4. As a result, an electric field is applied to the polarized piezoelectric material 2 in the same direction as the polarization direction of the piezoelectric material 2, and even if the strength of the electric field is increased, the electric field applied in the same direction as the polarization direction of the piezoelectric material 2 is increased. Does not break the polarization of the piezoelectric material 2 because it acts on the piezoelectric material 2 so as to promote the polarization of the piezoelectric material 2, and the electric field applied to the piezoelectric material 2 in the same direction as the polarization direction of the piezoelectric material 2 By increasing the strength, the amount of bending displacement of the diaphragm 1 can be increased without hindrance, and the pump output of the piezoelectric diaphragm pump can be easily increased accordingly.

According to a second aspect of the present invention, there is provided a piezoelectric diaphragm pump according to the first aspect, wherein a groove portion is provided on an upper surface of the housing and a terminal portion connected to the membrane electrode provided on the diaphragm is provided. The diaphragm 1 is housed in the groove 18 and the diaphragm 1 is installed on the upper surface of the housing 4 without any gap. As a result, the film-like electrode 1 provided on the diaphragm 1
When the diaphragm 1 is installed on the housing 4 with the housing 4 facing the housing 4, the terminal portion 16 connected to the film electrode 14 is housed in a groove 18 provided on the upper surface of the housing 4, and the diaphragm 1 is mounted on the housing 4. Since there is no gap on the upper surface of the body 4, the airtightness of the chamber 13 disposed between the diaphragm 1 and the housing 4 can be improved, and the compression ratio of the piezoelectric diaphragm pump can be improved to improve the pump output. Can be done.

According to a third aspect of the present invention, there is provided a piezoelectric diaphragm pump according to the first aspect, wherein the membrane electrode provided on the diaphragm covers the entire surface of the piezoelectric material.
The terminal portion 16 connected to the film-shaped electrode 14 and the film-shaped electrode 14 are formed integrally with a metal foil 30. Thereby, the diaphragm 1 can be installed on the upper surface of the housing 4 without any gap by forming the terminal portion 16 and the film-shaped electrode 14 on a plane, and the diaphragm 1 is disposed between the diaphragm 1 and the housing 4. The hermeticity of the chamber 13 can be improved, and the pump output can be improved by improving the compression ratio of the piezoelectric diaphragm pump.

According to a fourth aspect of the present invention, there is provided a piezoelectric diaphragm pump according to the first aspect, wherein the surface of the O-ring 20 formed along the outer periphery of the diaphragm 1 is coated with a conductive film 22 having conductivity. 1 membrane electrode 1
The O-ring 20 is interposed between the housing 4 and the housing 4. As a result, the O-ring 20 having a shape along the outer periphery of the diaphragm 1 is connected to the membrane electrode 1 of the diaphragm 1.
The diaphragm 1 is interposed between the housing 4 and the housing 4.
In this case, the diaphragm 1 can be installed in the housing 4 without any gaps. In this case, the O-ring 20 having the surface covered with the conductive film 22 having conductivity is coated with the O-ring 20 of the diaphragm 1. Since it is interposed between the electrode 14 and the housing 4, the electrical connection to the film electrode 14 is maintained, so that poor conductivity of the film electrode 14 can be avoided.

According to a fifth aspect of the present invention, there is provided a piezoelectric diaphragm pump according to the first aspect, wherein the O-ring 20 along the outer periphery of the diaphragm 1 is formed by dispersing and mixing fine particles 24 of a conductive material. The O-ring 20 is interposed between the membrane electrode 14 of the diaphragm 1 and the housing 4. As a result, the diaphragm 1 is installed on the housing 4 with the O-ring 20 having a shape along the outer periphery of the diaphragm 1 interposed between the membrane electrode 14 of the diaphragm 1 and the housing 4. The O-ring 20 is sandwiched between the diaphragm 1 and the housing 4 to deform the fine particles 24 of the conductive material. The O-ring 20 formed by dispersing and mixing has conductivity as a whole, so that the electrical connection with the film-like electrode 14 is reliably maintained, and the conduction failure of the film-like electrode 14 can be avoided. It is.

According to a sixth aspect of the present invention, there is provided a piezoelectric diaphragm pump according to the first aspect, wherein the seal ring has a shape along the outer periphery of the diaphragm and a flat cross section.
5 is formed of a resin film in which fine particles 24 of a conductive material are dispersed and mixed, and the seal ring 25 is interposed between the membrane electrode 14 of the diaphragm 1 and the housing 4.
This seal ring 25 is similar to the O-ring 20 described above.
The diaphragm 1 functions as a sealing material for installing the diaphragm 1 in the housing 4 without any gap. The diaphragm 1 can be installed in the housing 4 without any gap. For example, the O-ring 20 described above is made of a minute material. When it is difficult to obtain or when it is difficult to manufacture the circular groove 21 for accommodating the O-ring 20, it is effective to use the seal ring 25 instead of the O-ring 20, At this time, for example, if the seal ring 25 is a resin film applied on the housing 4, it is not necessary to form the groove 21 for accommodating the O-ring 20 in the housing 4. In addition, the productivity of the piezoelectric diaphragm pump is greatly improved.

According to a seventh aspect of the present invention, there is provided the piezoelectric diaphragm pump according to any one of the fourth to sixth aspects, wherein the diaphragm holding frame 19 for fixing the peripheral edge of the diaphragm 1 to the housing 4 is made of a transparent thermoplastic resin. It is characterized by being formed of resin. As a result, the diaphragm holding frame 1
9 is made of a transparent thermoplastic resin, the laser beam 2 irradiated from above the diaphragm holding frame 19
9 passes through the transparent diaphragm holding frame 19, and the laser light 29 melts the thermoplastic resin diaphragm holding frame 19 at the contact portion between the diaphragm holding frame 19 and the housing 4, and the laser light 29 melts the diaphragm holding frame 19 and the housing 4. Can be welded, and the diaphragm holding frame 1
The productivity of the piezoelectric diaphragm pump is improved as compared with the case where the fixing member 9 is fixed to the housing 4 via a fixing tool such as a bolt.

Further, in the piezoelectric diaphragm pump according to claim 8 of the present invention, in any one of claims 1 and 2, the film-shaped electrode 14 provided on the diaphragm 1 is provided in a portion other than the outer peripheral portion of one surface of the piezoelectric material 2. It is characterized by being covered over. This makes it possible to provide a structure in which a discharge that may occur between the film-like electrode 14 and the elastic plate 3 also serving as an electrode at the outer peripheral portion of the piezoelectric material 2 is unlikely to occur. Efficiency can be improved.

According to a ninth aspect of the present invention, there is provided a piezoelectric diaphragm pump according to any one of the first, second, and eighth aspects, wherein the membrane electrode 14 provided on the diaphragm 1 and the membrane electrode 14 are provided. At least one of the connecting terminal portion 16 and the elastic plate 3 having the function of an electrode is provided with an insulating portion 27 formed of an oxide film or the like on the surface in order to suppress discharge. As a result, a discharge that may occur between the film-like electrode 14 and the terminal portion 16 connected to the film-like electrode 14 and the elastic plate 3 having the function of an electrode causes the insulating portion 27 formed of the above-mentioned oxide film or the like. The discharge can be suppressed, and the efficiency of the piezoelectric diaphragm pump can be improved.

According to a tenth aspect of the present invention, in the piezoelectric diaphragm pump according to the ninth aspect, the elastic plate 3 and the ring-shaped insulating plate 28 having an outer diameter larger than that of the piezoelectric material 2 are arranged on the outer peripheral edge of the piezoelectric material 2. It is characterized by having done. As a result, a ring-shaped insulating plate 28 having a larger outer diameter than the elastic plate 3 and the piezoelectric material 2 may be formed between the elastic plate 3 and the terminal 16 connected to the film-shaped electrode 14 and the film-shaped electrode 14. Discharge with a certain amount can be cut off at the outer peripheral edge portion of the piezoelectric material 2, and the discharge can be suppressed to improve the efficiency of the piezoelectric diaphragm pump.

Further, according to a method for manufacturing a piezoelectric diaphragm pump according to claim 11 of the present invention, the diaphragm 1 is formed by laminating and attaching the elastic plate 3 to the piezoelectric material 2 and is opposite to the housing 4 in which the flow path is formed. The diaphragm 1 is mounted on the housing 4 with the elastic plate 3 positioned above in the direction, and a conductive paste 15 is applied to one surface of the piezoelectric material 2 on the housing 4 side and baked, and at least the metal foil 30 Is bonded to the piezoelectric material 2 with the baked conductive paste 15. Thereby, the diaphragm 1
In order to form an electrode of the piezoelectric material 2 on the housing 4 side, a conductive paste 15 is applied to the piezoelectric material 2 and baked, and the conductive material of the conductive paste 15 is left on the piezoelectric material 2 so that the housing of the piezoelectric material 2 is formed. An electrode can be easily formed on one surface of the body 4 side.
The terminal 16 formed on the piezoelectric material 2 or the film-like electrode 14 and the terminal 1 formed of an integrated metal foil 30
6 is provided on the piezoelectric material 2, the conductive paste 15
Can be simultaneously attached to the piezoelectric material 2 via the conductive paste 15 at the time of baking, so that the manufacture of the piezoelectric diaphragm pump can be simplified.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing a piezoelectric diaphragm pump according to the eleventh aspect, wherein the baking of the conductive paste 15 is performed in a vacuum atmosphere or a rare gas atmosphere 31. Thus, when the conductive paste 15 is baked in a vacuum atmosphere or a rare gas atmosphere 31, the metal foil 30 used for the film-like electrode 14 or the terminal portion 16 is fixed to the piezoelectric material 2, that is, the conductive paste When the baking process is performed on the metal foil 15, the metal foil 30 can be prevented from being oxidized, and the output performance of the piezoelectric diaphragm pump can be prevented from lowering.

According to a thirteenth aspect of the present invention, there is provided a method for manufacturing a piezoelectric diaphragm pump according to the eleventh or twelfth aspect.
5, the metal foil 30 constituting the film electrode 14 and the terminal portion 16 connected to the film electrode 14 is joined, and thereafter, the metal foil 30 is etched so as to reduce its thickness. . In other words, the metal foil 30 is formed in a moderately easy-to-handle thickness at the stage of preparation (before being joined to the piezoelectric material 2), and after the metal foil 30 is joined to the piezoelectric material 2 via the conductive paste 15. Is etched to a predetermined thickness to form a thin metal foil 30. By doing so, the metal foil 30 having a thickness that is easy to handle for bonding to the piezoelectric material 2 can be used. What is necessary is just to join the metal foil 30 to the piezoelectric material 2, and the joining operation of the metal foil 30 to the piezoelectric material 2 can be easily performed.
The thin metal foil 30 formed by edging after joining to the piezoelectric material 2 can obtain high dimensional accuracy.

According to a fourteenth aspect of the present invention, there is provided a method for manufacturing a piezoelectric diaphragm pump according to the eleventh or twelfth aspect.
The method is characterized in that the metal foil 30 ′ having a continuous shape is coated with the metal foil 30 ′ via the metal foil 5, and then the metal foil 30 ′ is etched into a predetermined shape. Thereby, the metal foil 3 having a continuous shape is formed.
When bonding 0 ′ to the piezoelectric material 2 via the conductive paste 15, the bonding can be easily performed without requiring accuracy, and the metal foil 30 ′ having a continuous shape is formed in the last step of forming the diaphragm 1. By forming the metal foil 30 having a predetermined shape by etching, high dimensional accuracy can be obtained for the metal foil 30 having a predetermined shape.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the accompanying drawings.

The piezoelectric diaphragm pump has a configuration in which the diaphragm 1 is mounted on a housing 4 having an inflow channel 5 and a discharge channel 6, and suction and exhaust of fluid is performed by bending deformation of the diaphragm 1. However, the basic structure of the piezoelectric diaphragm pump of the present example is also followed, and the piezoelectric diaphragm pump and the diaphragm 1 described in the section of the related art have the same configuration except for the diaphragm 1 part. The description will be made with reference to the drawings of a conventional piezoelectric diaphragm pump.

First, as shown in FIG. 2, the casing 4 having the inflow passage 5 and the discharge passage 6 is formed by interposing a membrane valve 7 between the upper casing 4a and the lower casing 4b. It is configured by lamination. The inflow channel 5 and the discharge channel 6 are formed in a groove shape on the upper surface of the lower housing 4b or on the upper surface of the lower housing 4b and the lower surface of the upper housing 4a. When the body 4a is covered, a tubular flow path is formed. The inflow passage 5 is provided with an inflow valve chamber 8 (FIG.
(See (b)), the discharge channel 6 communicates with a discharge valve chamber 9 (see FIG. 20C) located inside the housing 4. Here, the inflow valve chamber 8 and the discharge valve chamber 9 are hollow portions inside the housing 4 formed by the counterbore portions 11 provided in the lower housing 4b and the upper housing 4a, respectively. In the valve chamber 8, a valve pedestal 10 protrudes from the lower housing 4 b, and in the discharge valve chamber 9, the valve pedestal 10 protrudes from the upper housing 4 a. The seat surface of the valve seat 10 is positioned so as to close a valve hole 7a formed in the membrane valve 7 exposed to the inflow valve chamber 8 and the discharge valve chamber 9, respectively. That is, in the inflow valve chamber 8, the valve pedestal 10 blocks the valve hole 7 a formed in the membrane valve 7 from below, and in the discharge valve chamber 9, the valve hole 7 a pierced in the membrane valve 7 is closed. Is blocking from above. Further, chamber passages 12, 12 are formed in the upper housing 4a, and a chamber 13 and an inflow valve chamber 8, which will be described later, are formed.
The chamber 13 and the discharge valve chamber 9 communicate with each other. That is, the inflow passage 8 and the discharge passage 9 are connected to the chamber 1.
3 are communicated with each other. As will be described later, the chamber 13 refers to a space between the upper surface of the upper housing 4a and the lower surface of the diaphragm 1.

As shown in FIGS. 1B and 1C, the diaphragm 1 is formed by laminating a piezoelectric material 2 between an elastic plate 3 also serving as an electrode and a film electrode 14. Things. The elastic plate 3 serving as an electrode and the film-shaped electrode 14 function as an electrode for applying an electric field to the piezoelectric material 2. Since the electric field is applied to the whole of the piezoelectric material 2, substantially both surfaces of the piezoelectric material 2 are applied. Preferably, it is formed over the entire surface. Here, for example, PZT
[Pb (Zr, Ti) O ₃ ] is used. Further, for example, a brass plate is used for the elastic plate 3, but the elastic plate 3 can restrain the deformation of the piezoelectric material 2, and
Any material can be used as long as it can be an electrode. The film-shaped electrode 14 is provided over one surface of the piezoelectric material 2 on the side opposite to the side on which the elastic plate 3 is attached, as shown in FIG. It is formed in. This conductive paste 15
Uses, for example, a silver paste obtained by kneading a resin and silver powder. In addition, a terminal portion 16 connected to an external power supply for supplying a current to the film electrode 14 is provided on the film electrode 14.
In this example, the terminal portion 16 is bonded to the conductive paste 15 by using a thin metal foil 30. The terminal portion 16 and the elastic plate 3 serving as an electrode are connected to an external power supply, and an electric field can be applied between the film-like power supply 14 and the elastic plate 3, that is, over the entire surface of the piezoelectric material 2. It is something like that.

Diaphragm 1 configured as described above
Is mounted on the housing 4 as shown in FIG. At this time, the diaphragm 1 is placed on the housing 4 so that the elastic plate 3 is located above and the conductive paste 15 as the film electrode 14 is located below, and the conductive paste 15 is in contact with the upper surface of the housing 4. Have been.
Further, the diaphragm 1 is disposed on the housing 4 so as to hide the chamber passages 12 and 12 formed in the upper housing 4a. As shown in FIG. 3B, the diaphragm 1 arranged on the housing 4 is fixed to the housing 4 by applying an adhesive 17 over an outer peripheral portion thereof.
By fixing only the outer peripheral portion of the diaphragm 1 to the housing 4 in this manner, the diaphragm 1 has a degree of freedom only in the axial direction, and a chamber provided between the diaphragm 1 and the housing 4. 13 is made airtight.

The piezoelectric diaphragm pump formed as described above applies an electric field to the piezoelectric material 2 of the diaphragm 1 to bend the diaphragm 1 upwardly on the opposite side to the housing 4 so as to bend and deform the chamber 13. The capacity of the chamber 13 is reduced by increasing the volume of the chamber 1 or by allowing the diaphragm 1 to follow the housing 4 without any gap, so that the air is sucked into the chamber 13 from the inflow channel 5 or the discharge channel is discharged. 6, the atmosphere in the chamber 13 is exhausted. Hereinafter, the pump operation of the piezoelectric diaphragm pump will be described in detail.

In the above-described piezoelectric diaphragm pump, FIG.
As shown in FIG. 5, when an electric field applied to the piezoelectric material 2 of the diaphragm 1 is applied in the same direction as the polarization direction of the piezoelectric material 2 (arrow a) (arrow b), the diaphragm 1 projects upward on the opposite side to the housing 4. And the capacity of the chamber 13 is increased. That is, the piezoelectric material 2 to which the electric field is applied in the same direction as the polarization direction expands in the axial direction as shown in FIG. 25A (arrow c) [contracts in the radial direction as shown in FIG. (Arrow c)]. Since the diaphragm 1 has the elastic plate 3 provided above the piezoelectric material 2 as described above, the elastic material 3 restrains the deformed piezoelectric material 2 so that the elastic plate 3 contracts in the radial direction. It is bent and deformed in a convex shape upward on the opposite side of the housing 4. Then, the capacity of the chamber 13 provided between the diaphragm 1 and the housing 4 is increased.

At this time, since the pressure of the atmosphere in the chamber 13 becomes lower than the atmospheric pressure, the film valve 7 is pulled upward. As shown in FIG. 21B, in the inflow valve chamber 8, the valve hole 7a is separated from the seating surface of the valve seat 10, and the inflow valve is opened. On the other hand, in the discharge valve chamber 9, the valve hole 7a is held down by the valve seat 10 located above, and the discharge valve is closed. Thus, the atmosphere flows into the chamber 13 through the inflow passage 5 and the inflow valve.

On the other hand, when an electric field applied to the piezoelectric material 2 is applied in a direction opposite to the polarization direction of the piezoelectric material 2, the diaphragm 1 follows the housing 4 without any gap, and the chamber 13
Is almost eliminated. That is, the piezoelectric material 2 to which the electric field is applied in the direction opposite to the polarization direction is deformed and deformed so as to expand in the radial direction, and the piezoelectric material 2 that is deformed and deformed so as to expand in the radial direction is located above the piezoelectric material 2. Since the elastic deformation of the piezoelectric material 2 is constrained by the elastic plate 3 installed in the housing 1, the diaphragm 1 is to be bent and deformed downward in the direction of the housing 4. Here, since the casing 4 is a rigid body, the diaphragm 1 that is to be bent and deformed downward in a convex shape comes to be positioned along the casing 4 without any gap. When the diaphragm 1 is positioned along the housing 4 without any gap, the chamber 13
Is almost eliminated.

At this time, the air existing in the chamber 13 is compressed by the diaphragm 1 which is going to be bent and deformed downward, and the air pushes down the membrane valve 7. In the discharge valve chamber 9, the valve hole 7a is separated from the seat surface of the valve seat 10, and the discharge valve is opened. In the inflow valve chamber 8, the valve hole 7a is tightly closed from below by the seating surface of the valve seat 10, and the inflow valve is closed. Thus, the atmosphere in the chamber 13 is discharged through the discharge valve and the discharge flow path 6.

As described above, by changing the direction of the electric field applied to the piezoelectric material 2 of the diaphragm 1, the air flows into or out of the chamber 13. By alternately applying an electric field in the same direction as the polarization direction of the piezoelectric material 2 and in the opposite direction, the bending deformation of the diaphragm 1 is continuously performed so that the bending deformation is alternately vertically convex.
A pump operation for sucking the atmosphere from the inflow channel 5 into the chamber 13 and discharging the atmosphere in the chamber 13 from the discharge channel 6 is continuously performed.

Here, assuming that the same direction as the polarization direction of the piezoelectric material 2 is an electric field in the plus direction and the opposite direction is an electric field in the minus direction, the electric field applied to the piezoelectric material 2 in the piezoelectric diaphragm pump of this embodiment is -90 V It is performed in the range of +310 V. The reason that the strength of the electric field applied in the plus direction, that is, the same direction as the polarization direction of the piezoelectric material 2 is increased is that the amount of upward bending deformation of the diaphragm 1 on the opposite side to the housing 4 is increased. Thus, it is intended to increase the maximum capacity of the chamber 13 and increase the output of the piezoelectric diaphragm pump.

The piezoelectric diaphragm pump of this embodiment has a configuration in which when an electric field is applied in the same direction as the polarization direction of the piezoelectric material 2, the diaphragm 1 bends and deforms in a convex shape upward on the side opposite to the housing 4. Therefore, in order to increase the amount of bending deformation of the diaphragm 1 in the upward convex shape on the opposite side to the housing 4 and to increase the capacity of the chamber 13, the piezoelectric material 2 needs to be in the same direction as the polarization direction of the piezoelectric material 2. What is necessary is just to apply a strong electric field in the direction. As shown in the graph of FIG. 27, even when a strong electric field is applied to the piezoelectric material 2 in the same direction as the polarization direction of the piezoelectric material 2, there is no coercive electric field that reverses the polarization direction of the piezoelectric material 2. Yes, even if a strong electric field is applied to the piezoelectric material 2 in the same direction as the polarization direction of the piezoelectric material 2, the amount of bending displacement of the diaphragm 1 can be increased without any problem, and the pump output of the piezoelectric diaphragm pump is increased accordingly. Is what you can do.

In this embodiment, the structure in which the elastic plate 3 also serves as an electrode is exemplified. However, the present invention is not limited to this, and an electrode plate may be provided separately from the elastic plate 3. This is the same in each of the following examples.

Hereinafter, another example of the embodiment will be described. Since other examples of the following embodiments are obtained by partially changing the examples of the above-described embodiments, the description of the overlapping parts will be omitted, and differences will be mainly described.

In another example of the embodiment shown in FIG. 4, a groove 18 is provided on the upper surface of the housing 4, and the terminal 16 connected to the membrane electrode 14 provided on the diaphragm 1 is housed in the groove 18.
The diaphragm 1 is installed on the upper surface of a housing 4 without any gap. Here, the terminal portion 16 is formed of silver foil. As described above, even when the terminal portion 16 connected to the film electrode 14 is laminated and joined to the film electrode 14,
A groove 18 having substantially the same shape as the terminal portion 16 is provided on the upper surface of the housing 4 in advance, and the terminal portion 16 is housed in the groove portion 18. 4, the airtightness of the chamber 13 provided between the diaphragm 1 and the housing 4 can be improved, the compression ratio of the piezoelectric diaphragm pump can be improved, and the pump output of the piezoelectric diaphragm pump can be improved. Can be improved.

In another example of the embodiment shown in FIG. 5, the film electrode 14 provided on the diaphragm 1 covers the whole surface of the piezoelectric material 2 and the terminal 16 and the film electrode 14 are
Are formed integrally. In the example of FIG. 4 described above,
Although the groove portion 18 for accommodating the terminal portion 16 is formed in the upper surface of the housing 4, in this example, the terminal portion 16 and the film electrode 14 are formed integrally with the metal foil 30. Since the terminal portion 16 and the film electrode 14 are formed in a flat shape without any level difference, it is possible to prevent the diaphragm 1 from being tilted to the housing 4 while saving the trouble of providing the groove portion 18. The diaphragm 1 can be installed on the upper surface of the housing 4 without any gap, and the airtightness of the chamber 13 provided between the diaphragm 1 and the housing 4 can be improved, and the compression ratio of the piezoelectric diaphragm pump can be improved. Thus, the pump output of the piezoelectric diaphragm pump can be improved.

Another example of the embodiment shown in FIG. 6 is to provide a diaphragm holding frame 19 for sandwiching the outer peripheral portion of the diaphragm 1 with the housing 4, and to attach an O-ring 20 having a shape along the outer periphery of the diaphragm 1 to a diaphragm. 1 and the diaphragm holding frame 19, and between the diaphragm 1 and the housing 4 (upper housing 4a), the diaphragm 1 is
And a surface of an O-ring 20 serving as a sealant interposed between the diaphragm 1 and the housing 4 (upper housing 4a) and coated with a conductive film 22 having conductivity. The O-ring 20 is brought into contact with the membrane electrode 14 to be electrically connected. More specifically, O 4 is provided on the upper surface of the housing 4 (upper housing 4a).
A circular groove 21 conforming to the shape of the ring 20 is provided in advance, a conductive film 23 is provided on the bottom surface of the circular groove 21, and the O-ring 20 is electrically connected to the conductive film 23 and the film electrode 14. The diaphragm holding frame 19 is screwed to the housing 4 so as to be housed in the circular groove portion 21 and sandwich the diaphragm 1 between the housing 4. By doing so, the O-ring 20 serving as a sealing material
The diaphragm 1 can be installed in the housing 4 without gaps by using the O-ring 20 having a surface covered with a conductive film 22 having conductivity.
Between the film-like electrode 14 and the housing 4
The electrical connection to the film-like electrode 14 is maintained so that poor conductivity of the film-like electrode 14 can be avoided.

In another example of the embodiment shown in FIG. 7, an O-ring 20 along the outer periphery of the diaphragm 1 is formed by dispersing and mixing fine particles 24 of a conductive material. Thus, in the present example, the entire O-ring 20 is made conductive. In the case of the O-ring 20 in FIG. 6, when the O-ring 20 is deformed by being sandwiched between the diaphragm 1 and the housing 4. Although there is a possibility that the conductive film 22 may be peeled off, the electrical connection between the O-ring 20 of the present embodiment and the membrane electrode 14 of the diaphragm 1 is securely maintained even if the shape of the O-ring 20 is deformed. It is possible to avoid poor conductivity of the electrode 14. It is preferable to use carbon black or metal fine particles as the fine particles 24 of the conductive material.

Another example of the embodiment shown in FIG. 8 is that a seal ring 25 having a shape along the outer periphery of the diaphragm 1 and a flat cross section is formed of a resin film in which fine particles 24 of a conductive material are dispersed and mixed. The seal ring 25 is interposed between the membrane electrode 14 of the diaphragm 1 and the housing 4. The seal ring 25 is a resin film having a certain degree of elasticity in which fine particles 24 of a conductive material are dispersed and mixed, and is applied to the upper surface of the housing 4 (upper housing 4a). When the diaphragm 1 is installed in the housing 4 by the diaphragm holding frame 19, similarly to the above-described O-ring 20, it functions as a sealing material for installing the diaphragm 1 in the housing 4 without gaps. When the O-ring 20 is very small and difficult to manufacture and obtain, or when it is difficult to manufacture the circular groove 21 for accommodating the O-ring 20, the seal ring 25 may be used. It is effective to use the seal ring 25 instead, and the seal ring 25 is applied to the upper surface of the housing 4 (upper housing 4a). It is not necessary to make a hole, and the productivity of the piezoelectric diaphragm pump is greatly improved.

In another example of the embodiment shown in FIG. 9, a diaphragm holding frame 19 for fixing the peripheral edge of the diaphragm 1 to the housing 4 is formed of a transparent thermoplastic resin. Since the diaphragm holding frame 19 is made of a transparent thermoplastic resin as described above, the diaphragm holding frame 1
The laser beam 29 irradiated from above is passed through a transparent diaphragm holding frame 19, and the laser beam 29 melts the thermoplastic resin diaphragm holding frame 19 at a portion of the diaphragm holding frame 19 in contact with the housing 4. The holding frame 19 and the housing 4 can be welded to each other, which improves the productivity of the piezoelectric diaphragm pump.

Another example of the embodiment shown in FIGS. 10 to 12 is that the diaphragm 1 is applied as it is to apply an electric field to substantially the entire surface of the piezoelectric material 2 of the elastic plate 3 which also serves as an electrode. The structure has a structure in which a discharge that may occur between the membrane electrode 14 and the elastic plate 3 also serving as an electrode at the outer peripheral portion of the piezoelectric diaphragm pump is hardly generated, and the discharge is suppressed to improve the efficiency of the piezoelectric diaphragm pump. is there. Note that the one shown in FIG. 10 is one in which the film-like electrode 14 is formed over the outer surface of one surface of the piezoelectric material 2. In the one shown in FIG. 11, the film-like electrode 14 is formed over the outer peripheral portion of one surface of the piezoelectric material 2, and the film-like electrode 14 is formed at a portion corresponding to the terminal portion 16 connected to the film-like electrode 14 of the elastic plate 3 also serving as an electrode. Notch 2
6 is provided to avoid a discharge that may occur between the terminal portion 16 and the elastic plate 3 also serving as an electrode. Here, in the one shown in FIG. 12, the film-like electrode 14 is formed over an area other than the outer peripheral portion of one surface of the piezoelectric material 2, and the elastic plate 3 also serving as an electrode extends over an area other than the outer peripheral portion of the other surface of the piezoelectric material 2. That is, the film-shaped electrode 14 and the elastic plate 3 serving also as an electrode are formed so as to have a diameter slightly smaller than the diameter of the piezoelectric material 2.
This is to avoid discharge that may occur between the film-like electrode 14 and the terminal portion 16 and the elastic plate 3 also serving as an electrode.

Another example of the embodiment shown in FIG.
The film electrode 14 provided on the diaphragm 1, the film electrode 1
At least one of the terminal portion 16 connected to the substrate 4 and the elastic plate 3 having an electrode function is provided with an insulating portion 27 formed of an oxide film or the like on the surface in order to suppress discharge. With this configuration, a discharge that may occur between the film electrode 14 and the terminal portion 16 connected to the film electrode 14 and the elastic plate 3 having an electrode function is formed by the oxide film or the like. The insulating portion 27 can be cut off to suppress the discharge and improve the efficiency of the piezoelectric diaphragm pump. Here, what is shown in FIG. 13 is the above-described insulating portion 27 in a portion of the terminal portion 16 close to the diaphragm 1.
In FIG. 14, the insulating portion 27 is provided over the periphery of the elastic plate 3 having the function of an electrode.

Another example of the embodiment shown in FIG.
A ring-shaped insulating plate 28 having a larger outer diameter than the elastic plate 3 and the piezoelectric material 2 is arranged on the outer peripheral edge of the piezoelectric material 2.
Accordingly, a discharge that may occur between the elastic electrode 3 and the film-like electrode 14 and the terminal portion 16 connected to the film-like electrode 14 can be cut off by the insulating plate 28, and the discharge can be suppressed and the piezoelectric diaphragm can be suppressed. The efficiency of the pump can be improved. It is preferable that the outer diameter of the insulating plate 28 be larger than the outer diameters of the elastic plate 3 and the piezoelectric material 2 by about 0.1 to 0.2 mm.

Here, the membrane electrode 14 and the membrane electrode 14 of the diaphragm 1 of the piezoelectric diaphragm pump described above are used.
FIG. 16 shows an example of a method of fixing the terminal portion 16 connected to the piezoelectric material 2 to the piezoelectric material 2. In FIG. 16A, the film electrode 14 is formed of a conductive paste 15, and the terminal 16 connected to the film electrode 14 is formed of a strip-shaped metal foil 30.
In FIG. 16B, the film electrode 14 and the terminal portion 16 are formed integrally with a metal foil 30. In both of these examples, a conductive paste 15 in which a conductor and a resin are kneaded is applied and baked over the surface of the piezoelectric material 2 opposite to the surface on which the elastic plate 3 is provided. Conductive paste 1
When baking treatment is performed on the resin material 5, the resin contained in the conductive paste 15 is vaporized, and the conductor remains in the form of a film on the surface of the piezoelectric material 2. The conductive paste 15 remaining on the surface of the piezoelectric material 2 after the baking treatment becomes a good conductive material having a small amount of resin and a small electric resistance. In FIG. The film-shaped conductor remaining on the surface of the piezoelectric material 2 of the processed conductive paste 15 is used as the film-shaped electrode 14. In this embodiment, a silver paste obtained by kneading silver powder and a resin is used as the conductive paste 15.

When the conductive paste 15 is baked, the metal foil 3 of the terminal portion 16 shown in FIG.
The metal paste 30 for forming the film-like electrode 14 and the terminal portion 16 shown in FIG. 16B or FIG. 16B is brought into contact with the conductive paste 15. The resin is vaporized, and the conductor of the conductive paste 15 is fixed on the surface of the piezoelectric material 2 in the form of a film and remains, but at this time, the conductive paste 15 of FIG. 16 and FIG.
(B) The film-like electrode 14 and the terminal portion 16 are fixed to the piezoelectric material 2. By performing the baking treatment on the conductive paste 15 in this manner, the electric resistance of the conductive paste 15 is reduced by the conductor remaining on the surface of the piezoelectric material 2 by evaporating the resin contained in the conductive paste 15 to reduce the film-like electrode 14. Or to fix the film-like electrodes 14 and the terminal portions 16 formed of the metal foil 30 to the piezoelectric material 2.

Further, as shown in FIG.
5 is preferably performed in a vacuum atmosphere or a rare gas atmosphere 31. In this way, when the metal foil 30 used for the film electrode 14 and the terminal portion 16 is fixed to the piezoelectric material 2, that is, when the conductive paste 15 is baked, the metal foil 30 is oxidized. That is, it is possible to prevent the output performance of the piezoelectric diaphragm pump from being lowered.

Here, as described above, the piezoelectric material 2
To the film electrode 14 or the film electrode 1 via the conductive paste 15
It is also preferable that the metal foil 30 constituting the terminal portion 16 connected to the metal foil 4 is joined, and thereafter, the etching is performed so that the thickness of the metal foil 30 is reduced. In other words, the metal foil 30 is formed in a moderately easy-to-handle thickness at the stage of preparation (before being joined to the piezoelectric material 2), and after the metal foil 30 is joined to the piezoelectric material 2 via the conductive paste 15. Is etched to a predetermined thickness to form a thin metal foil 30. The reason why the metal foil 30 is formed thin is that the metal foil 30
Of the metal foil 30 when the diaphragm 1 is formed.
This is to prevent the strain deformation of the piezoelectric material 2 from being restricted. However, if the thin metal film 30 is formed before joining to the piezoelectric material 2, it is difficult to handle the joining operation to the piezoelectric material 2. Therefore, the use of the metal foil 30 having a suitable and easy-to-handle thickness for bonding to the piezoelectric material 2 as in the present method makes it possible to perform the bonding easily. By etching the metal foil 30 bonded to the material 2 so as to be thin, it is possible to form the metal foil 30 with high dimensional accuracy. As this etching, it is preferable to perform etching using an ion beam rather than wet etching. According to the ion beam etching, the entire surface of the metal foil 30 can be uniformly thinned. In addition, as the metal foil 30, FIG.
As shown in FIG. 16 (b), the film-like electrode 14 is formed of a conductive paste 15 and the terminal 16 connected to the film-like electrode 14 is formed of a metal foil 30. As shown in FIG.
4 and the terminal portion 16 connected to the film-like electrode 14 may be constituted by an integrated metal foil 30, but this method can be applied to the formation of both the metal foils 30.

It is also preferable to coat the piezoelectric material 2 with a continuous metal foil 30 ′ via the conductive paste 15 and then to etch the metal foil 30 ′ into a predetermined shape. In other words, the metal foil 30 ′ may have an appropriate shape that is easy to handle (before being joined to the piezoelectric material 2) (in this case, the metal foil 30 ′ is formed in a continuous shape). After bonding to the piezoelectric material 2 through the metal foil 30, the metal foil 30 ′ having the same surface shape is etched so that the metal foil 30 has a predetermined shape.
This method does not require accuracy when joining the continuous-shaped metal foil 30 ′ to the piezoelectric material 2 via the conductive paste 15.
And can be easily joined to the diaphragm.
A metal foil 30 'having a continuous shape in the last step of formation
Is etched to form a metal foil 30 having a predetermined shape, so that a high dimensional accuracy can be obtained for the metal foil 30 having a predetermined shape. For example, in the case of a piezoelectric diaphragm pump in which the terminal portion 16 made of the metal foil 30 is housed in the groove portion 18 provided in the housing 4 as shown in FIG. However, this method is particularly effective when high dimensional accuracy is required for such a metal foil 30. Here, FIG.
In this case, a metal foil 30 ′ having a continuous shape is bonded to the piezoelectric material 2 via the conductive paste 15, and thereafter, the metal foil 3
0 ′ is etched to form a terminal portion 16 as shown in FIG.
Is formed on the metal foil 30 of FIG.
The metal foil 30 'having a continuous shape can be etched so as to form the metal foil 30 in which the film-like electrode 14 and the terminal portion 16 are integrated as shown in FIG.

[0052]

As described above, in the piezoelectric diaphragm pump according to the first aspect of the present invention, a diaphragm is formed by a piezoelectric material and an elastic plate, and the diaphragm is mounted on a housing in which a flow path is formed. In a piezoelectric diaphragm pump that sucks and exhausts fluid by bending displacement of the diaphragm, an electric field is applied to the polarized piezoelectric material in the same direction as the polarization direction of the piezoelectric material, so that the diaphragm moves upward on the opposite side to the housing. Since the bending displacement is performed in a convex shape, an electric field is applied to the polarized piezoelectric material in the same direction as the polarization direction of the piezoelectric material, and even if the strength of the electric field is increased, the polarization direction of the piezoelectric material is changed. The electric field applied in the same direction acts on the piezoelectric material so as to promote the polarization of the piezoelectric material, so it does not break the polarization of the piezoelectric material. Strongly the intensity of the electric field pressure can be increased without any trouble flexural displacement amount of the diaphragm, in which it is possible to easily achieve an increase in the pump output of the piezoelectric diaphragm pump accordingly.

According to a second aspect of the present invention, in addition to the effect of the first aspect, a groove is provided on the upper surface of the housing, and the terminal for connecting to the membrane electrode provided on the diaphragm is provided. Since the diaphragm was placed in the groove and the diaphragm was installed on the upper surface of the housing without any gap, when the membrane electrode provided on the diaphragm was placed on the housing side and the diaphragm was installed on the housing, the terminal portion connected to the membrane electrode was removed. The piezoelectric diaphragm can be housed in the groove provided on the upper surface of the housing and the diaphragm can be installed on the upper surface of the housing without any gap, and the airtightness of the chamber disposed between the diaphragm and the housing can be improved. The pump output can be improved by increasing the compression ratio of the pump.

In the piezoelectric diaphragm pump according to the third aspect of the present invention, in addition to the effect of the first aspect, the membrane electrode provided on the diaphragm covers the whole surface of the piezoelectric material and is connected to the membrane electrode. Since the terminal portion and the film-like electrode are integrally formed of metal foil, the diaphragm can be installed on the upper surface of the housing without any gap by forming the terminal portion and the film-like electrode on a plane, and the The airtightness of the chamber disposed between the housing and the housing can be improved, and the compression ratio of the piezoelectric diaphragm pump can be improved to improve the pump output.

According to a fourth aspect of the present invention, in addition to the effect of the first aspect, in addition to the effect of the first aspect, the surface of the O-ring shaped along the outer periphery of the diaphragm is coated with a conductive film having conductivity. Since the above-mentioned O-ring was interposed between the membrane electrode of the diaphragm and the housing, the O-ring having a shape along the outer periphery of the diaphragm was interposed between the membrane electrode of the diaphragm and the housing to form the housing. Since it is installed on the body, the diaphragm can be installed in the housing without any gaps. In this case, an O-ring coated on the surface with a conductive film having conductivity is connected to the membrane electrode of the diaphragm and the housing. Therefore, the electrical connection to the above-mentioned film-shaped electrode is maintained, so that the poor conductivity of the film-shaped electrode can be avoided.

According to a fifth aspect of the present invention, in addition to the effect of the first aspect, in addition to the effect of the first aspect, an O-ring shaped along the outer periphery of the diaphragm is formed by dispersing and mixing fine particles of a conductive material. Since the O-ring is interposed between the membrane electrode of the diaphragm and the housing, the O-ring shaped along the outer periphery of the diaphragm is interposed between the membrane electrode of the diaphragm and the housing to form the diaphragm. Since the diaphragm is installed in the housing, the diaphragm can be installed in the housing without any gap.In this case, even when the O-ring is sandwiched between the diaphragm and the housing and its shape is deformed, Since the O-ring formed by dispersing and mixing the fine particles of the conductive material has conductivity as a whole, the electrical connection with the film-shaped electrode is securely maintained, and the poor conductivity of the film-shaped electrode can be avoided. It is those that can.

According to a sixth aspect of the present invention, in addition to the effect of the first aspect, in addition to the effect of the first aspect, a seal ring having a shape along the outer periphery of the diaphragm and having a flat cross section is formed by removing fine particles of a conductive material. It is formed of a resin film mixed and dispersed, and the seal ring is interposed between the membrane electrode of the diaphragm and the housing. Therefore, like the O-ring described above, this seal ring seals the diaphragm in the housing without any gap. Because it works as a material, the diaphragm can be installed in the housing without gaps, for example,
When it is difficult to manufacture or obtain the above-mentioned O-ring due to its small size, or when it is difficult to manufacture a circular groove for accommodating the O-ring, use the seal ring instead of the O-ring. In this case, for example, if the seal ring is a resin film applied on the housing, it is not necessary to form a groove for accommodating the O-ring in the housing. Thus, the productivity of the piezoelectric diaphragm pump is greatly improved.

According to the piezoelectric diaphragm pump of the present invention, in addition to the effect of any one of the fourth to sixth aspects, the diaphragm holding frame for fixing the peripheral edge of the diaphragm to the housing is made of a transparent heat-transmissive frame. Since it is formed of a thermoplastic resin, the laser light irradiated from above the diaphragm holding frame passes through the transparent diaphragm holding frame, and the laser light is applied to the diaphragm holding frame of the thermoplastic resin at the contact portion between the diaphragm holding frame and the housing. Is melted to weld the diaphragm holding frame and the housing, thereby improving the manufacturability of the piezoelectric diaphragm pump.

According to the piezoelectric diaphragm pump of the present invention, in addition to the effect of any one of the first and second aspects, in addition to the effect of the first or second aspect, the film-shaped electrode provided on the diaphragm is formed on a portion other than the outer peripheral portion of one surface of the piezoelectric material. The piezoelectric diaphragm pump can be structured such that a discharge that may occur between the film-shaped electrode and the elastic plate also serving as an electrode at the outer peripheral portion of the piezoelectric material is unlikely to occur. Efficiency can be improved.

According to the piezoelectric diaphragm pump of the ninth aspect of the present invention, in addition to the effect of any one of the first, second and eighth aspects, a film-like electrode provided on the diaphragm, In order to suppress discharge, at least one of the terminal part and the elastic plate having the function of an electrode is provided with an insulating part made of an oxide film or the like on the surface, so that it is connected to the film electrode and the film electrode. The discharge which may occur between the terminal portion to be formed and the elastic plate having the function of the electrode can be interrupted by the insulating portion formed by the oxide film or the like, and the discharge is suppressed to reduce the efficiency of the piezoelectric diaphragm pump. Can be improved.

According to a tenth aspect of the present invention, in addition to the effect of the ninth aspect, in addition to the effect of the ninth aspect, an elastic plate and a ring-shaped insulating plate having an outer diameter larger than that of the piezoelectric material are arranged on the outer peripheral edge of the piezoelectric material. Therefore, the elastic plate and the insulating plate formed into a ring shape having a larger outer diameter than the piezoelectric material generate a discharge that may occur between the elastic plate and the film electrode and the terminal portion connected to the film electrode. The discharge can be suppressed at the outer peripheral edge portion, and the discharge can be suppressed, and the efficiency of the piezoelectric diaphragm pump can be improved.

Further, according to a method of manufacturing a piezoelectric diaphragm pump according to claim 11 of the present invention, an elastic plate is laminated and adhered to a piezoelectric material to form a diaphragm, and the diaphragm is formed upward in a direction opposite to a casing in which a flow path is formed. The diaphragm is placed on the housing with the elastic plate positioned, and a conductive paste is applied and baked on one surface of the piezoelectric material on the housing side, and at least a terminal portion formed of a metal foil is baked on the conductive paste. In order to form the electrode on the housing side of the piezoelectric material of the diaphragm, a conductive paste is applied to the piezoelectric material and baked to leave the conductive material of the conductive paste on the piezoelectric material. An electrode can be easily formed on one surface of the housing side of the case, and a terminal portion of a metal foil to be connected to the electrode is provided on a piezoelectric material, or a film is formed of an integrated metal foil. Even when the electrodes and the terminals are provided on the piezoelectric material, the electrodes can be fixed to the piezoelectric material via the conductive paste at the same time as the conductive paste is baked, so that the manufacture of the piezoelectric diaphragm pump can be simplified. .

In the method for manufacturing a piezoelectric diaphragm pump according to the twelfth aspect of the present invention, in addition to the effect of the eleventh aspect, the baking of the conductive paste is performed in a vacuum atmosphere or a rare gas atmosphere. When the metal foil used for the electrodes and terminals is fixed to the piezoelectric material, that is, when the conductive paste is baked, the metal foil is prevented from being oxidized, and the output performance of the piezoelectric diaphragm pump is prevented from deteriorating. Is what you can do.

According to a thirteenth aspect of the present invention, there is provided a method for manufacturing a piezoelectric diaphragm pump according to any one of the eleventh and twelfth aspects, wherein the piezoelectric material is connected to the film-shaped electrode or the film-shaped electrode via a conductive paste. Since the metal foil constituting the terminal portion to be bonded is joined and then etched so as to reduce the thickness of the metal foil, the piezoelectric material is formed using a metal foil having a thickness that is easy to handle for joining to the piezoelectric material. The metal foil may be bonded to the piezoelectric material, and the bonding of the metal foil to the piezoelectric material can be easily performed.The thin metal foil formed by being edged after the bonding to the piezoelectric material is formed. Can obtain high dimensional accuracy.

A method of manufacturing a piezoelectric diaphragm pump according to a fourteenth aspect of the present invention is the method according to the eleventh or twelfth aspect, wherein the piezoelectric material is covered with a metal foil having a continuous shape via a conductive paste. Thereafter, since the metal foil is etched into a predetermined shape, the metal foil having a continuous shape can be easily bonded to the piezoelectric material via the conductive paste without requiring precision, and
By etching a metal foil having a shape continuous with the last step of forming a diaphragm to form a metal foil having a predetermined shape, high dimensional accuracy can be obtained for the metal foil having a predetermined shape.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of a piezoelectric diaphragm pump according to the present invention, in which (a) is a side sectional view and (b).
FIG. 3 is a perspective view of the diaphragm as viewed from the top side, and FIG.
FIG. 4 is a perspective view of the diaphragm viewed from the lower surface side, and FIG.
FIG. 7 is an explanatory diagram of the operation of the diaphragm.

FIGS. 2A and 2B show the same housing, in which FIG. 2A is an exploded perspective view and FIG. 2B is a perspective view.

FIGS. 3A and 3B are perspective views of the same piezoelectric diaphragm pump, FIG. 3A is a perspective view of the diaphragm, and FIG. 3B is an overall perspective view of the piezoelectric diaphragm pump.

FIG. 4 is a side sectional view showing another example of the above embodiment.

FIG. 5 illustrates another example of the above embodiment.
(A) is a side view, (b) is a perspective view seen from the upper surface side of the diaphragm, (c) is a perspective view seen from the lower surface side of the diaphragm.

FIG. 6 shows another example of the above embodiment.
(A) is a side sectional view, (b) is a sectional view taken along line AA of (a), and (c) is a sectional view taken along line BB of (b).

FIG. 7 shows another example of the above embodiment,
(A) is a side sectional view, (b) is a sectional view taken along line CC of (a), and (c) is a sectional view taken along line DD of (b).

FIG. 8 shows another example of the above embodiment,
(A) is a side sectional view, (b) is a sectional view taken along line EE of (a), and (c) is a sectional view taken along line FF of (b).

FIG. 9 is a side sectional view showing another example of the above embodiment.

FIG. 10 shows another example of the above embodiment.
(A) is a perspective view seen from the upper surface side of the diaphragm,
(B) is a perspective view seen from the lower surface side of the diaphragm,
(C) is a side view of the diaphragm.

FIG. 11 shows another example of the above embodiment.
(A) is a top view of a diaphragm, (b) is (a)
FIG. 7 is a sectional view taken along line GG of FIG.

FIG. 12 shows another example of the above embodiment.
(A) is a perspective view seen from the upper surface side of the diaphragm,
(B) is a perspective view seen from the lower surface side of the diaphragm,
(C) is a side view of the diaphragm.

FIG. 13 shows another example of the above embodiment,
(A) is a perspective view seen from the upper surface of the diaphragm,
(B) is a side view of the diaphragm.

FIG. 14 shows another example of the above embodiment.
(A) is a perspective view seen from the upper surface side of the diaphragm,
(B) is a perspective view seen from the lower surface side of the diaphragm,
(C) is a side sectional view of the diaphragm.

FIG. 15 shows another example of the above embodiment,
(A) is a top view of a diaphragm, (b) is a side view of a diaphragm, (c) is an enlarged view of H part of (b).

16A and 16B are explanatory diagrams for explaining a method of manufacturing a diaphragm portion of the above piezoelectric diaphragm pump. FIG. 16A is a diagram in which a film-shaped electrode is formed of a conductive paste, and a terminal connected to the film-shaped electrode is a strip-shaped metal. It is the perspective view which looked at the diaphragm formed from foil from the lower side, and (b) is the perspective view which looked at the diaphragm which the film-form electrode and the terminal part were integrally formed by the metal foil from the lower side.

17A and 17B are explanatory diagrams illustrating a method of manufacturing a diaphragm portion of the above piezoelectric diaphragm pump. FIG. 17A is a diagram in which a film-shaped electrode is formed of a conductive paste and a terminal connected to the film-shaped electrode is a strip-shaped metal. It is the perspective view which looked at the diaphragm formed from foil from the lower side, and (b) is the perspective view which looked at the diaphragm which the film-form electrode and the terminal part were integrally formed by the metal foil from the lower side.

18A and 18B are explanatory views illustrating a method for manufacturing a diaphragm portion of the piezoelectric diaphragm pump, in which FIG. 18A is a perspective view illustrating a state in which a continuous-shaped metal foil is joined to the diaphragm, and FIG. FIG. 3 is a perspective view of a diaphragm showing a state in which a continuous shape of metal foil is etched to form a metal foil of a predetermined shape, as viewed from above, and FIG. It is the perspective view seen, and (d) is a side sectional view of the piezoelectric diaphragm pump manufactured by the above-mentioned method.

FIG. 19 is a side view showing a conventional piezoelectric diaphragm pump.

20A and 20B show the structure of a conventional piezoelectric diaphragm pump, wherein FIG. 20A is an exploded perspective view, FIG. 20B is a side sectional view of an intake valve chamber, and FIG. 20C is a side view of an exhaust valve chamber. It is sectional drawing.

FIGS. 21A and 21B are explanatory views illustrating the operation of a conventional piezoelectric diaphragm pump, wherein FIG. 21A is a side sectional view,
(B) is a side sectional view of the inflow valve chamber.

FIG. 22 is an explanatory view for explaining the operation of the piezoelectric diaphragm pump according to the related art, where (a) is a side sectional view,
(B) is a side sectional view of the discharge valve chamber.

23A and 23B are explanatory diagrams illustrating the operation of a conventional piezoelectric diaphragm pump, wherein FIG. 23A is an explanatory diagram illustrating a force generated inside the diaphragm, and FIG. 23B is a side cross-sectional view illustrating bending deformation of the diaphragm; FIG.

24A and 24B are explanatory diagrams illustrating the operation of a conventional piezoelectric diaphragm pump, wherein FIG. 24A is an explanatory diagram illustrating a force generated inside the diaphragm, and FIG. 24B is a side cross-sectional view illustrating bending deformation of the diaphragm; FIG.

FIGS. 25A and 25B are explanatory views illustrating the operation of a conventional piezoelectric diaphragm pump, and FIGS. 25A and 25B are explanatory views illustrating distortion deformation of a piezoelectric material.

FIGS. 26A and 26B are explanatory views illustrating the operation of a conventional piezoelectric diaphragm pump. FIGS. 26A and 26B are schematic side views showing the direction of an electric field applied to a piezoelectric material and the polarization direction of the piezoelectric material. .

FIG. 27 is a graph showing the relationship between the amount of strain deformation of a piezoelectric material and the magnitude of an electric field applied to the piezoelectric material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diaphragm 2 Piezoelectric material 3 Elastic plate 4 Housing

Claims (14)

[Claims] 1. A piezoelectric diaphragm pump in which a diaphragm is formed by a piezoelectric material and an elastic plate, the diaphragm is installed on a casing having a flow path formed therein, and a fluid is sucked and exhausted by bending displacement of the diaphragm. A piezoelectric diaphragm pump characterized in that an electric field is applied to the piezoelectric material in the same direction as the polarization direction of the piezoelectric material so that the diaphragm bends upwardly on the opposite side to the housing. 2. A groove is provided on an upper surface of a housing, a terminal portion connected to a membrane electrode provided on the diaphragm is housed in the groove, and the diaphragm is installed on the upper surface of the housing without a gap. Item 2. The piezoelectric diaphragm pump according to item 1. 3. A film-like electrode provided on a diaphragm covers an entire surface of a piezoelectric material, and a terminal portion connected to the film-like electrode and the film-like electrode are integrally formed of a metal foil. 4. The piezoelectric diaphragm pump according to 1. 4. A surface of an O-ring shaped along the outer periphery of the diaphragm is coated with a conductive film having conductivity, and the O-ring is interposed between the membrane electrode of the diaphragm and the housing. The piezoelectric diaphragm pump according to claim 1, wherein 5. An O-ring having a shape along the outer periphery of a diaphragm formed by dispersing and mixing fine particles of a conductive material, and interposing the O-ring between a membrane electrode of the diaphragm and a housing. The piezoelectric diaphragm pump according to claim 1, wherein: 6. A seal ring having a shape along the outer periphery of the diaphragm and having a flat cross section is formed of a resin film in which fine particles of a conductive material are dispersed and mixed, and the seal ring is formed between the membrane electrode of the diaphragm and the housing. The piezoelectric diaphragm pump according to claim 1, wherein a seal ring is interposed. 7. The piezoelectric diaphragm pump according to claim 4, wherein a diaphragm holding frame for fixing a peripheral edge of the diaphragm to the housing is formed of a transparent thermoplastic resin. 8. The piezoelectric diaphragm pump according to claim 1, wherein the membrane-like electrode provided on the diaphragm covers a portion other than an outer peripheral portion of one surface of the piezoelectric material. 9. An oxide film or the like is formed on the surface of at least one of a membrane electrode provided on the diaphragm, a terminal portion connected to the membrane electrode, and an elastic plate having an electrode function to suppress discharge. 9. The piezoelectric diaphragm pump according to claim 1, wherein the insulating portion is provided. 10. The piezoelectric diaphragm pump according to claim 9, wherein an elastic plate and a ring-shaped insulating plate having an outer diameter larger than that of the piezoelectric material are arranged on an outer peripheral edge of the piezoelectric material. 11. A diaphragm is formed by laminating and attaching an elastic plate to a piezoelectric material, and the elastic plate is positioned above the housing in which a flow path is formed in a direction opposite to the housing, and the diaphragm is mounted on the housing. Manufacturing a piezoelectric diaphragm pump, wherein a conductive paste is applied and baked on one surface of the piezoelectric material on the housing side, and at least a terminal portion formed of a metal foil is joined to the piezoelectric material with the baked conductive paste. Method. 12. The method according to claim 11, wherein the baking of the conductive paste is performed in a vacuum atmosphere or a rare gas atmosphere. 13. A method for bonding a film-shaped electrode or a metal foil constituting a terminal portion connected to the film-shaped electrode to a piezoelectric material via a conductive paste, and thereafter performing etching to reduce the thickness of the metal foil. Claim 11 or Claim 1 characterized by the following:
3. The method for manufacturing the piezoelectric diaphragm pump according to any one of 2. 14. The piezoelectric material is covered with a metal foil having a continuous shape via a conductive paste, and thereafter, the metal foil is etched into a predetermined shape. 3. The method for manufacturing a piezoelectric diaphragm pump according to item 1.