WO2018016630A1

WO2018016630A1 - Piezoelectric vibration generating device and instrument provided with piezoelectric vibration generating device

Info

Publication number: WO2018016630A1
Application number: PCT/JP2017/026486
Authority: WO
Inventors: 清有沢; 雅人林
Original assignee: 北陸電気工業株式会社
Priority date: 2016-07-21
Filing date: 2017-07-21
Publication date: 2018-01-25
Also published as: JPWO2018016630A1

Abstract

Provided are: a piezoelectric vibration generating device that is finished with less manufacturing time and has a longer lifespan than the prior art, and that uses a circular vibrating plate and piezoelectric vibrating element; and an instrument provided with said piezoelectric vibration generating device. A vibrating shaft 17 is configured from a metal screw member arranged so as to pass through a third through-hole 4 provided to a vibrating plate 3, a second through-hole 13 of a piezoelectric vibrating element 15, and a first through-hole 5 of a first case half-section 7, so that a head part 17C is positioned on a side near a second case half-section 9 and a screw part 17D at the distal end extends out to the exterior of the first case half-section 7. A metal nut member 19 is fitted with the screw part 17D.

Description

Piezoelectric vibration generating device and apparatus including the piezoelectric vibration generating device

The present invention relates to a piezoelectric vibration generating device and a device including the piezoelectric vibration generating device.

Japanese Patent Laid-Open No. 2001-17917 (Patent Document 1) describes a piezoelectric vibration used for a mobile terminal such as a smartphone or a mobile phone, a device of a tablet terminal, or the like to vibrate the display screen when the display screen is touched. An example of a generating device is disclosed. The piezoelectric vibration generating device shown in FIGS. 1 and 2 of Patent Document 1 includes a disk-shaped diaphragm (1), and a first case half having a first through hole in the center and made of an electrically insulating material ( 5a) and an insulating case (5) configured by combining a second case half (5b) made of an electrically insulating material sandwiching the outer periphery of the diaphragm between the first case half and the diaphragm (1 ) And one or more disk-shaped piezoelectric vibration elements (2) having a second through-hole in the center and one end connected to the center of the vibration plate, and the second through-hole of the piezoelectric vibration element And a vibration shaft (4) extending through the hole and the first through hole of the first case half and extending to the outside of the first case half.

Japanese Patent Laid-Open No. 2001-17917, FIGS. 1 and 2

In the piezoelectric vibration generating device described in Patent Document 1, since the vibration plate and the piezoelectric vibration element have a disk shape or an annular shape, the piezoelectric vibration generation device using the rectangular vibration plate and the rectangular piezoelectric vibration element. Larger vibration can be obtained.

Although not specifically described in Patent Document 1, it is considered that the vibration axis is bonded to the center of the diaphragm when estimated based on FIGS. 1 and 2 of Patent Document 1 and the description thereof.

However, when the vibration shaft and the vibration plate are joined by bonding, there is a high possibility that peeling will occur at the bonded portion if used for a long time. In particular, if vibration is applied to a heavy object to be fixed such as an operation panel of an automobile or an operation panel of various machines via a vibration shaft, the strength of the adhesion portion is not sufficient. Is destroyed, and a problem occurs that the life span is shortened in a short period of time.

An object of the present invention is to provide a piezoelectric vibration generating device using a disk-shaped diaphragm and a piezoelectric vibration element having high mechanical strength and a long life, and an apparatus including the piezoelectric vibration generating device. .

According to the present invention, an outer peripheral portion of a diaphragm is formed between a metal disk-shaped diaphragm, a first case half having a first through hole in the center and made of an electrically insulating material, and a first case half. An insulating case formed by combining second case halves made of an electrically insulating material to be sandwiched, and one or more disk-shaped piezoelectric vibrating elements joined to one or both sides of the diaphragm and having a second through hole in the center And one end connected to the central part of the diaphragm, and the other end extending through the second through hole of the piezoelectric vibration element and the first through hole of the first case half and extending to the outside of the first case half. A piezoelectric vibration generating device having a shaft is an object of improvement. In the piezoelectric vibration generating device of the present invention, the third through hole is formed at the center of the diaphragm. The vibration shaft passes through the third through hole, the second through hole, and the first through hole so that the head portion is located on the second case half side and the screw portion at the tip extends to the outside of the first case half portion. It consists of a screw member arranged to do. In addition, a nut member is screwed into the threaded portion or a retaining washer is fitted. In addition, in this specification, a nut member contains the components of the apparatus provided with the internal thread part formed in the driven member which transmits a vibration other than a general nut.

As in the present invention, using a screw member and a nut member or a retaining washer, and attaching the vibration shaft to the diaphragm, it does not take time to join both, and compared to the case where both are joined by bonding, High bond strength can be obtained. In addition, since the vibration shaft of the piezoelectric vibration generating device can be coupled to the component of the device to be vibrated by screw coupling, it is easy to mount and high coupling strength can be obtained.

It is preferable that the second through half of the second case is formed with a fourth through hole having a size corresponding to the head of the screw member. Even if the fourth through hole is provided, the amplitude of the diaphragm increases. Since the fourth through hole serves as a clearance space for the head of the screw member, the diaphragm can be vibrated with a large amplitude without increasing the thickness.

From the viewpoint of mechanical strength, the nut member or retaining washer is preferably made of metal. In this case, since a short circuit problem occurs, an insulating washer made of an electrically insulating material is disposed between the retaining washer or the nut member and the diaphragm and between the diaphragm and the head of the screw member. That's fine. Note that the nut member or the retaining washer may be formed of a material other than metal.

The insulating washer is preferably a resin washer. Since the resin washer is more flexible than the metal washer, the vibration of the diaphragm is restrained more than necessary, and the vibration is not significantly reduced. Of course, the insulating washer may be formed of other insulating materials such as ceramic. Of course, the insulating washer may be replaced with a metal washer.

It is preferable that the diaphragm is formed with a plurality of slits that penetrate the diaphragm in the thickness direction and are arranged at intervals in the circumferential direction so as to surround the periphery of the piezoelectric vibration element. By providing such a plurality of slits, the flexibility of the diaphragm can be made within a desired range without significantly reducing the mechanical strength of the diaphragm. Therefore, the amplitude of the diaphragm can be increased.

The diaphragm is further disposed in the circumferential direction so as to penetrate the diaphragm in the thickness direction and be positioned between the piezoelectric vibration element and the second through hole so as to surround the periphery of the second through hole. Preferably, a plurality of slits are formed. Such a plurality of slits also contributes to making the diaphragm flexible in a desired range, which is useful for further increasing the amplitude of the diaphragm.

A standing wall portion that rises toward the first case half or the second case half may be provided integrally with the outer peripheral portion of the diaphragm. When such a standing wall portion is provided, the standing wall portion is in contact with the first case half and the second case half and the diaphragm is between the first case half or the second case half. Since it is sandwiched, the substantial diameter of the diaphragm can be maximized, and the vibration of the diaphragm can be further increased.

The piezoelectric vibration element may be a unimorph type piezoelectric vibration element, but of course, a bimorph piezoelectric vibration element may be used to obtain stronger vibration.

When the piezoelectric vibration generating device of the present invention is used in a device such as an operation panel of a portable terminal or an automobile, the vibration shaft or the insulating case of the piezoelectric vibration generating device may be fixed to the fixed part of the device. . Needless to say, both the vibration shaft of the piezoelectric vibration generating device and the insulating case may be fixed to a pair of fixed parts facing each other.

It is sectional drawing of an example of the piezoelectric vibration generation device using the unimorph piezoelectric vibration element of this invention. FIG. 2 is a half sectional perspective view of the piezoelectric vibration generating device of FIG. 1. It is sectional drawing of the piezoelectric vibration generating device of 2nd Embodiment of the piezoelectric vibration generating device of this invention. FIG. 4 is a half sectional perspective view of the piezoelectric vibration generating device of FIG. 3. (A) is a plan view of a diaphragm used in the third embodiment, and (B) is a half-sectional cross-sectional perspective view taken along the line BB of FIG. 5 (A). It is sectional drawing of the piezoelectric vibration generating device of 4th Embodiment of the piezoelectric vibration generating device of this invention. FIG. 7 is a half cross-sectional perspective view of the piezoelectric vibration generating device of FIG. 6. It is sectional drawing which shows the other example in the case of fixing the piezoelectric vibration generating device of 5th Embodiment of the piezoelectric vibration generating device of this invention to the case of a portable terminal. It is sectional drawing of an example of the piezoelectric vibration generating device of 6th Embodiment of the piezoelectric vibration generating device of this invention. FIG. 10 is a half sectional perspective view of the piezoelectric vibration generating device of FIG. 9. It is sectional drawing of an example of the piezoelectric vibration generating device of 7th Embodiment of the piezoelectric vibration generating device of this invention.

Embodiments of the piezoelectric vibration generating device of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of an example of a piezoelectric vibration generating device 1 using a unimorph piezoelectric vibration element of the present invention, and FIG. 2 is a half sectional perspective view of the piezoelectric vibration generating device 1 of FIG.

1 and 2, a piezoelectric vibration generating device 1 includes a disk-shaped or annular diaphragm 3 made of metal (brass in the present embodiment) and a first through hole 5 in the center, and an electrically insulating material. An insulating case 11 configured by combining a first case half 7 and a second case half 9 made of an electrically insulating material sandwiching the outer periphery of the diaphragm 3 between the first case half 7 and the first case half 7; A disk-shaped or annular piezoelectric vibration element 15 having a second through-hole 13 in the center and bonded to one surface of the vibration plate 3 and one end 17A are connected to the central portion of the vibration plate 3, 2 and a vibration shaft 17 extending through the first through hole 5 of the first case half 7 and the other end 17 </ b> B extending to the outside of the first case half 7. The first case half 7 and the second case half 9 are each integrally formed of an insulating resin material, and constitute an insulating case 11 with the diaphragm 3 sandwiched therebetween. The second case half 9 is formed with a fourth through hole 10 having a size that allows the head portion 17C to pass therethrough corresponding to the head portion 17C of the screw member constituting the vibration shaft 17. When the fourth through hole 10 is provided, even when the amplitude of the diaphragm 3 is increased, the fourth through hole 10 becomes a clearance space for the head portion 17C of the screw member (17), so that the thickness is not increased. The diaphragm can be vibrated with a large amplitude.

In the present embodiment, the insulating case 11 is fitted into the fitting hole 12A of the insulating resin mounting frame 12 having a cylindrical fitting hole 12A at the center and fixed to the mounting frame 12 using an adhesive. Has been. In the present embodiment, the mounting frame 12 is composed of a cylindrical tube body 12B and a flange portion 12C. In the present embodiment, the mounting frame 12 is used by being fixed to a case (fixed portion) of a portable terminal, an operation panel of a device such as an automobile, or the like. Attachment is performed by inserting attachment screws into attachment holes 12D provided in the attachment frame 12.

In the piezoelectric vibration generating device 1 of the present embodiment, the third through hole 4 is formed at the center of the diaphragm 3. In this embodiment, the vibration shaft 17 has a head (other end) 17C positioned on the second case half 9 side, and a screw portion 17D at the tip (one end 17A) extending to the outside of the first case half 7. It is comprised from the metal (stainless steel) screw member arrange | positioned so that it may penetrate through the 3rd through-hole 4, the 2nd through-hole 13, and the 1st through-hole 5. As shown in FIG. A metal (stainless steel) nut member 19 is fitted to the screw portion 17D.

When the vibration shaft 17 is attached to the diaphragm 3 by using the screw member (17) and the nut member 19 as in the present invention, it does not take time to join the two, and compared to the case where both are joined by bonding. Thus, a high bond strength can be obtained.

The unimorph piezoelectric vibration element 15 has an annular shape. The piezoelectric vibration element 15 is provided with electrodes on both main surfaces and polarized in the thickness direction. Electric power is supplied to the piezoelectric vibration element 15 by electrically connecting to electrodes provided on two main surfaces in the thickness direction of the piezoelectric vibration element 15 using lead wires (not shown). Of the electrodes formed on one main surface of the piezoelectric vibration element 15, the electrode on the metal diaphragm 3 side includes, for example, the material of the metal diaphragm 3 made of a conductor such as metal, If the metallic diaphragm 3 and the piezoelectric vibration element 15 are bonded to each other with a conductive adhesive, they can be electrically connected. At this time, even if the adhesive used for bonding is not conductive, the electrical connection can be ensured by bonding the metal diaphragm 3 and the piezoelectric vibration element 15 so as to partially contact each other with the surface roughness. can do.

In the present embodiment, the nut member 19 is made of metal from the viewpoint of mechanical strength. However, since a short circuit problem occurs, in the present embodiment, the nut member 19 and the diaphragm 3

Insulating washers

20A and 20B made of an electrically insulating material are arranged between the diaphragm 3 and the head 17C of the screw member (17).

The operation of the piezoelectric vibration generating device according to the embodiment of the present invention having the above configuration will be described. When an AC voltage having a resonance frequency of flexural vibration of the vibration plate 3 is applied in the thickness direction of the piezoelectric vibration element 15, the piezoelectric vibration element 15 is excited, and the vibration plate 3 is near its center, that is, near the center of the piezoelectric vibration element 15. The vibration is flexed and vibrated in the thickness direction so that the maximum displacement is obtained. Further, in the vibration plate 3, the flexural vibration generated from the piezoelectric vibration element 15 propagates to the entire metal vibration plate 3. The vibration of the diaphragm 3 is transmitted to the vibration shaft 17 as it is, and the vibration of the vibration shaft 17 can be taken out of the piezoelectric vibration generating device 1 as a driving force. In Figure 1, the threaded portion 17D of the end of the vibrating shaft 17 is fixed to the driven member 21, the driven member 21 vibrates.

In the above embodiment, a unimorph piezoelectric vibration element is used, but a bimorph piezoelectric vibration element may be used instead of the unimorph piezoelectric vibration element.

In the above embodiment, the nut member 19 prevents the screw member (17) from coming off, but instead of the nut member 19, a retaining washer is attached to the screw portion 17D of the screw member (17) constituting the vibration shaft. Of course, they may be fitted. The retaining washer is a well-known washer having a plurality of claw portions that protrude radially inward from the inside of an annular washer body and are provided at predetermined intervals in the circumferential direction. The plurality of claw portions are fitted into the thread valleys of the screw portion 17D of the screw member (17), thereby realizing the retaining.

(Embodiment 2)
FIG. 3 is a sectional view of an example of the piezoelectric vibration generating device 1 of the second embodiment of the piezoelectric vibration generating device of the present invention, and FIG. 4 is a half sectional perspective view of the piezoelectric vibration generating device 1 of FIG. It is. 3 and 4, the same reference numerals as those in FIGS. 1 and 2 are assigned to the same portions as those in the first embodiment shown in FIGS. 1 and 2. In the first embodiment, the piezoelectric vibration element 15 is attached to one side of the diaphragm 3, but in the second embodiment, the

piezoelectric vibration elements

15A and 15B are provided on both sides of the diaphragm 3, respectively. This is different from the first embodiment. In other respects, the configuration is the same as that of the first embodiment.

(Embodiment 3)
FIG. 5A is a plan view of the diaphragm 3 used in the third embodiment, and FIG. 5B is a cross-sectional perspective view taken along the line BB in FIG. 5A. The diaphragm 3 is formed with a plurality of slits 14 penetrating the diaphragm 3 in the thickness direction and arranged at intervals in the circumferential direction so as to surround the periphery of the

piezoelectric vibration elements

15A and 15B. . When such a plurality of slits 14 are provided, the flexibility of the diaphragm 3 can be in a desired range without significantly reducing the mechanical strength of the diaphragm 3. Therefore, the amplitude of the diaphragm can be increased.

5A, the diaphragm 3 further penetrates the diaphragm 3 in the thickness direction, and is located between the piezoelectric vibrating

elements

15A and 15B and the second through hole 13. A plurality of slits 14 ′ arranged at intervals in the circumferential direction so as to surround the periphery of the second through hole 13 may be formed. Such a plurality of slits 14 ′ also contributes to making the flexibility of the diaphragm 3 within a desired range, which is useful when the amplitude of the diaphragm is further increased.

(Embodiment 4)
FIG. 6 is a cross-sectional view of an example of the piezoelectric vibration generating device 1 of the fourth embodiment of the piezoelectric vibration generating device of the present invention, and FIG. 7 is a half sectional perspective view of the piezoelectric vibration generating device 1 of FIG. It is. In FIGS. 6 and 7, the same reference numerals as those in FIGS. 1 to 4 are attached to the same portions as those in the first embodiment and the second embodiment shown in FIGS. It is. In the first embodiment and the second embodiment, a flat diaphragm 3 is used. However, in the fourth embodiment, the first case half 7 is formed on the outer periphery of the diaphragm 30. A standing wall portion 30 </ b> A that rises toward the ′ side is integrally provided. When such a standing wall portion 30A is provided, the standing wall portion 30A comes into contact with the first case half portion 7 'and the second case half portion 9 so that the diaphragm 30 is in contact with the first case half portion 7'. Since it is sandwiched between the two case halves 9, the substantial diameter of the diaphragm 30 can be maximized, and the vibration of the diaphragm 30 can be increased. In the present embodiment, the standing wall 30A stands on the first case half 7 'side, but it goes without saying that the standing wall 30A may rise on the second case half 9 side.

(Embodiment 5)
FIG. 8 is a cross-sectional view showing another example of the case where the piezoelectric vibration generating device 1 according to the fifth embodiment of the piezoelectric vibration generating device of the present invention is fixed to the case 23 (fixed portion) of the mobile terminal. In FIG. 8, the same parts as those in the first embodiment and the second embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals as those in FIGS. In the present embodiment, the screw portion 17D of the vibration shaft 17 is screwed to the case 23. In this example, the mounting frame 12 functions as a weight. In the present embodiment, a screwdriver is inserted into a driver slot (not shown) provided in the head 17C of the screw member constituting the vibration shaft 17, and the screw portion 17D of the vibration shaft 17 is screwed into the female screw portion provided in the case 23. By doing so, the attachment of the piezoelectric vibration generating device 1 is completed.

(Embodiment 6)
FIG. 9 is a cross-sectional view of an example of the piezoelectric vibration generating device 1 according to the sixth embodiment of the piezoelectric vibration generating device of the present invention, and FIG. 10 is a half sectional perspective view of the piezoelectric vibration generating device 1 of FIG. It is. 9 and 10, the same reference numerals as those in FIGS. 1 to 4 are attached to the same portions as those in the first and second embodiments shown in FIGS. It is. In the first embodiment and the second embodiment, the mounting frame 12 is composed of a cylindrical cylindrical body 12B and a flange portion 12C. In the present embodiment, the mounting frame 12 and the first frame are the same. The case half 7 is integrally formed. Other points are the same as in the first and second embodiments. When such an integrated structure is adopted, the number of parts can be reduced. In the first to fifth embodiments, it is needless to say that a structure in which the mounting frame 12 and the first case half 7 are integrally formed may be employed.

(Embodiment 7)
FIG. 11 is a cross-sectional view of an example of the piezoelectric vibration generating device 1 according to the seventh embodiment of the piezoelectric vibration generating device of the present invention. FIG. 10 shows the first embodiment shown in FIGS. The same reference numerals as those shown in FIG. 1 and FIG. The present embodiment is different from the first embodiment in that the length of the vibration shaft 17 is long and the stopper 18 is fixed to the first case half 7. The stopper 18 is in contact with the vibrating body 21 that vibrates and regulates the vibration range in the radial direction of the vibrating body 21 fixed to the screw portion 17D of the vibration shaft 17. The stopper 18 may have a cylindrical shape with the vibration shaft 17 as the center, or may be a protrusion arranged in an annular shape at intervals in the circumferential direction.

According to the present invention, when the vibration shaft is attached to the diaphragm using the screw member and the nut member or the retaining washer, it does not take time for the coupling operation of both, and compared to the case where both are joined by bonding, High bond strength can be obtained. In addition, since the vibration shaft of the piezoelectric vibration generating device can be coupled to the component of the device to be vibrated by screw coupling, it is easy to mount and high coupling strength can be obtained.

DESCRIPTION OF SYMBOLS 1 Piezoelectric vibration generating device 3 Diaphragm 4 3rd through-hole 5 1st through-hole 7 1st case half 9 Second case half 10 4th through-hole 11 Insulation case 12 Mounting frame 13 2nd through-hole 15 Piezoelectric vibration element 17 Vibrating shaft 18 Stopper 19 Retaining washer 21 Vibrated body 23 Case

Claims

A metal disc-shaped diaphragm,
A first case half made of an electrically insulating material having a first through hole in the center and a second case half made of an electrically insulating material sandwiching the outer periphery of the diaphragm between the first case half and the first case half An insulated case configured and
One or more disk-shaped piezoelectric vibration elements bonded to one or both surfaces of the vibration plate and having a second through hole in the center;
One end is connected to the central portion of the diaphragm, the second through hole of the piezoelectric vibration element and the first through hole of the first case half, and the other end outside the first case half. A piezoelectric vibration generating device having a vibration axis extending to
A third through hole is formed in the center of the diaphragm;
The vibration shaft includes the third through hole, the second through hole, and the first through hole so that a head portion is positioned on the second case half side and a screw portion at a tip extends outside the first case half portion. It consists of a screw member arranged to penetrate one through hole,
A piezoelectric vibration generating device, wherein a nut member is screwed to the screw member or a retaining washer is fitted.
The piezoelectric vibration generating device according to claim 1, wherein a fourth through hole having a size through which the head can pass is formed in the second case half corresponding to the head of the screw member.
The nut member or the retaining washer is made of metal,
An insulating washer made of an electrically insulating material is disposed between the nut member or the retaining washer and the diaphragm and between the diaphragm and the head of the screw member, respectively. The piezoelectric vibration generating device according to 1.
The piezoelectric vibration generating device according to claim 3, wherein the insulating washer is a resin washer.
2. The plurality of slits are formed in the diaphragm so as to penetrate the diaphragm in the thickness direction and are arranged at intervals in the circumferential direction so as to surround the periphery of the piezoelectric vibration element. 5. The piezoelectric vibration generating device according to any one of 4 above.
The diaphragm is spaced in the circumferential direction so as to penetrate the diaphragm in the thickness direction and to be located between the piezoelectric vibrating element and the second through hole and to surround the second through hole. The piezoelectric vibration generating device according to claim 5, wherein a plurality of slits arranged with gaps are formed.
The piezoelectric vibration generating device according to claim 6, wherein an upstanding wall portion that rises toward the first case half portion or the second case half portion side is integrally provided on an outer peripheral portion of the diaphragm.
The piezoelectric vibration generating device according to any one of claims 1 to 7, wherein the piezoelectric vibration element is a bimorph piezoelectric vibration element.
9. An apparatus, wherein the vibration shaft or the insulating case of the piezoelectric vibration generating device according to claim 1 is fixed to a fixed part.
9. The apparatus according to claim 1, wherein the vibration shaft and the insulating case of the piezoelectric vibration generating device according to any one of claims 1 to 8 are respectively fixed to a pair of opposed fixed portions.