JPH11275875A - Piezoelectric generator and portable device equipped with the piezoelectric generator - Google Patents

Abstract

(57) [Summary] [Problem] To provide a piezoelectric power generation device with high power generation efficiency capable of efficiently transmitting energy applied by a vibration means to a piezoelectric body. SOLUTION: A piezoelectric body 9 for generating electric power by utilizing a piezoelectric effect, and a vibrating means 1 for giving vibration to the piezoelectric body 9 are provided.
3 and a contact portion 11 that contacts the piezoelectric body 9 when a part of the piezoelectric body 9 is fixed so that the piezoelectric body 9 can be vibrated.
and a fixing means 11 having a contact portion 11a formed thereon and having a base portion 11b serving as a base for the contact portion 11a. The piezoelectric power generator 1 wherein the thickness t2 of the portion 11b is greater than the thickness t1 of the piezoelectric body 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric generator for generating electric power by utilizing the piezoelectric effect of a piezoelectric body, and to a portable device having the piezoelectric generator.

[0002]

2. Description of the Related Art Some portable devices such as a pager or a wristwatch have a secondary battery, and this secondary battery is charged by a power generator. 2. Description of the Related Art There is a conventional power generation device that generates electric power by applying electric power generated by a piezoelectric effect of a piezoelectric body by applying a displacement to a piezoelectric body (hereinafter, referred to as a piezoelectric power generation device). A piezoelectric power generating device using such a piezoelectric body is disclosed in Japanese Patent Application Laid-Open No. 56-64677.
According to the present invention, the piezoelectric power generating device includes a piezoelectric body, a disk-shaped vibration plate having the piezoelectric body attached to one surface, a vibrating section for vibrating the vibration plate to apply vibration to the piezoelectric body, and There is a fixing means for fixing the periphery of the diaphragm when vibrating by the vibrating section.

[0003] When a user uses a wristwatch equipped with the piezoelectric power generating device, a vibrating section that vibrates in response to the operation of the user causes the vibrating plate to vibrate to apply displacement to the piezoelectric body.
The piezoelectric body to which the displacement has been applied converts mechanical energy into electrical energy by a piezoelectric effect, so that an output is taken out from an electrode provided on the piezoelectric body. The output is rectified by a rectifier circuit and charged to a charging unit such as a secondary battery.

[0004]

However, the piezoelectric generator having such a configuration has the following disadvantages.

[0005] In the method of fixing the periphery of the vibration plate provided with the piezoelectric body, the vibration applied to the piezoelectric body easily escapes to the fixed portion, so that there is a loss of energy.

In the method of fixing the periphery of the diaphragm on which the piezoelectric body is provided, a strong fixing portion is required, so that such a large-scale piezoelectric generator cannot be mounted on a portable device.

If the piezoelectric body is provided only on one side of the diaphragm, the electromechanical coupling coefficient (ratio of converting mechanical energy to electrical energy) is small.

[0008] An object of the present invention is to solve the above problems,
An object of the present invention is to provide a piezoelectric power generation device with high power generation efficiency capable of efficiently transmitting the energy applied by the vibration means to the piezoelectric body.

[0009]

According to a first aspect of the present invention, there is provided a piezoelectric body for generating electric power by utilizing a piezoelectric effect, a vibration means for applying vibration to the piezoelectric body, and a vibrating means for vibrating the piezoelectric body. When a part of the piezoelectric body is fixed, an abutting portion that comes into contact with the piezoelectric body, and a fixing portion having the abutting portion formed thereon and serving as a base for the abutting portion. Means, wherein the thickness of the base portion in the direction in which the vibration means applies vibration is greater than the thickness of the piezoelectric body.

According to the first aspect of the present invention, the piezoelectric body that generates electric power by utilizing the piezoelectric effect is fixed so as to be able to vibrate by the contact portion provided on the base portion of the fixing means. The vibrating means converts mechanical energy into electric energy by vibrating the piezoelectric body to generate electric power. At this time, since the thickness of the base portion in the vibration direction of the vibration means is larger than the thickness of the piezoelectric body, the base portion is configured to be hardly affected by vibration. For this reason, even if the vibration of the piezoelectric body vibrated by the vibrating means gives unnecessary vibration to the base portion provided with the abutting portion for fixing the piezoelectric body, the vibration of the base portion becomes unnecessary. Does not occur. That is, the fixing means is prevented from resonating with the vibration of the piezoelectric body. Therefore, the vibrating means can efficiently transmit energy to the piezoelectric body when vibrating the piezoelectric body.

According to a second aspect of the present invention, in the configuration of the first aspect, the thickness of the base portion in the direction in which the vibrating means applies vibration is partially thicker than the thickness of the piezoelectric body.

According to the configuration of the second aspect, even when the thickness of only a part of the base portion is larger than the thickness of the piezoelectric body, the base portion does not generate unnecessary vibration due to the vibration of the piezoelectric body. That is, the fixing means is prevented from resonating with the vibration of the piezoelectric body. Therefore, the vibrating means can efficiently transmit energy to the piezoelectric body when vibrating the piezoelectric body.

According to a third aspect of the present invention, in any one of the first and second aspects, the piezoelectric body is disposed at a position eccentric from a center of the base in a plane direction of the substantially flat base. ing.

According to the third aspect of the present invention, the piezoelectric member is disposed at a position away from the center of large vibration in the plane of the base portion, so that the fixing means resonates with the vibration of the piezoelectric member. Is prevented.

According to a fourth aspect of the present invention, in the configuration of the third aspect, the piezoelectric body is disposed at a node where no displacement occurs when the base portion vibrates.

According to the structure of the fourth aspect, the piezoelectric body is disposed at a position of the node which is not displaced in the vibration direction by the vibration means when the base portion vibrates. Resonance with vibration is prevented.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the cross-sectional shape of the base portion is curved.

According to the fifth aspect of the present invention, since the base has a curved structure, it is not affected by the vibration of the piezoelectric body.
The fixing means is prevented from resonating with the vibration of the piezoelectric body.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the outer peripheral shape of the base portion is a polygon.

According to this configuration, since the outer peripheral shape of the base portion is polygonal, it is not affected by the vibration of the piezoelectric body, and the fixing means resonates with the vibration of the piezoelectric body. Is prevented.

According to a seventh aspect of the present invention, in the configuration of any one of the first to sixth aspects, the base portion prevents the fixing means from vibrating when applied to the piezoelectric body by the vibrating means. Column-shaped vibration prevention means is provided.

According to the seventh aspect of the present invention, since the base portion is provided with the vibration preventing means for preventing the influence of the vibration of the piezoelectric body, the fixing means can prevent the vibration of the piezoelectric body from being affected. On the other hand, resonance is prevented.

According to an eighth aspect of the present invention, in the configuration of any one of the first to seventh aspects, the fixing means is made of a hard material.

According to the structure of the eighth aspect, since a hard material is used for the fixing means, the resonance frequency of the fixing means is increased. For this reason, the fixing means is prevented from resonating with the vibration of the piezoelectric body.

[0025]

Preferred embodiments of the present invention will be described below with reference to the drawings.

In the following description, the term "node" refers to a portion having the least amount of vibration when the object vibrates, and the term "antinode" refers to a portion having the largest amount of vibration when the object vibrates. .
The “distribution ratio (ηmod)” refers to energy applied to the piezoelectric body / (energy applied to the piezoelectric body + energy escaping to the fixed portion).

Embodiment 1 FIG. 1 is a schematic configuration diagram showing an example of the internal configuration of a portable device equipped with a piezoelectric power generating device according to a first embodiment of the present invention.

The portable device 2 is a device that can be carried by a user, such as a flashlight, a radio, a telephone device, a desktop computer, or a wristwatch. In the following description, the wristwatch 2 will be described as an example of a portable device. The wristwatch 2 includes a piezoelectric generator 1, a rectifier circuit 12, a charging unit 14, and a driving unit 16.
Etc.

This wristwatch 2 is composed of a piezoelectric generator 1 described later.
Are rectified by the rectifier circuit 12. The rectifier circuit 12 may be, for example, a full-wave rectifier circuit or a half-wave rectifier circuit. The rectifier circuit 12 supplies the rectified power to a charging unit 14 such as a secondary battery.
To charge. In the wristwatch 2, a driving unit 16 such as a built-in electronic circuit and a motor is driven using the power of the charging unit 14 as a power supply.

FIG. 2 is a plan view showing an example of the appearance of a portable device equipped with the piezoelectric power generating device of FIG.

Since the wristwatch 2 is equipped with the piezoelectric generator 1, the user can generate power intentionally.
The wristwatch 2 is, for example, an analog display type hand clock. The wristwatch 2 includes a case 15 serving as a side body, a dial 6 having a time stamped therein, and a dial 6 embedded in the case 15.
A hand 5 for indicating a time by pointing to a position indicating a predetermined time engraved in the upper glass 3, which is provided on one surface of the case 15, and through which the position of the hand 6 can be visually recognized. 15, a movement 8 having a drive system for moving the hands 5, a part of the movement 8, and a piezoelectric generator 1 for charging a secondary battery of the wristwatch 2; And a belt 30 and the like for enabling attachment to an arm or the like.

FIG. 3 is a sectional view of the wristwatch 2 shown in FIG. FIG. 4 is a plan view when the wristwatch 2 of FIG. 3 is viewed from the I direction. FIG. 5 is a perspective view showing the wristwatch 2 of FIG.

The piezoelectric generator 1 as a part of the movement 8 of the wristwatch 2 includes a crown 7, a gear 19, and a speed increasing gear 2.
1, cam 23, vibration lever 13 (vibration means), fixed part 1
1 (fixing means), a piezoelectric body 9 and the like.

The crown 7 is provided at one end outside the case 15 on a shaft 7 a provided from the inside of the case 15 to the outside, and a gear 17 is provided at the other end. When power is generated, the crown 7 is pinched and rotated by a user to rotate the shaft 7 a formed on one side of the crown 7, thereby rotating the gear 17 inside the case 15. The gear 17 meshes with a gear 19 inside the case 15. The gears 17 and 19 are respectively bulky gears.

The gear 19 is a shaft 1 fixed to the case 15.
A gear 19a is provided concentrically with 9b. The gear 19 is a gear 1 in which the crown 7 is provided on the opposite side via the shaft 7a.
It is meshed with 7. When the user rotates the crown 7, the gear 17 rotates.
Rotate around b. The gear 19a is fixed to the gear 19, and rotates when the gear 19 rotates. The speed increasing gear 21 is meshed with the gear 19a.

The speed-increasing gear 21 has a gear 19a interlocked with the gear 19 around a shaft 21b fixed to the case 15.
Is rotated by the rotation of. The speed increasing gear 21 is meshed with the gear 23a and the gear 19a. That is,
The speed-increasing gear 21 is a gear for transmitting the rotational force of the gear 19 to the gear 23a. The cam 23 has a disk-like shape in which convex portions 23d and concave portions 23c are alternately formed on the outer periphery as shown in FIG. It is a member. The cam 23 is fixed to a rotation shaft 23b rotatably fixed to the case 15, and rotates in conjunction with a gear 23a similarly fixed to the rotation shaft 23b. As shown in FIG. 7A, the convex portion 23d
By rotating in two directions, the tapered portion 13 of the vibration lever 13
e, and raises the vibration lever 13 in the R1 direction. When the cam 23 rotates in the X2 direction, the tapered portion 13e that has been in contact with the convex portion 23d falls into the concave portion 23c and fits therein. As shown in FIG. 7B, the vibration lever 13
It pivots in two directions and comes into contact with the piezoelectric body 9 and returns to a position where the piezoelectric body 9 is barely shaken.

The vibration lever 13 is a member for giving vibration to the piezoelectric body 9. The vibration lever 13 rotates in the direction R in FIG. 5 around a shaft hole 13a through which a shaft 4a provided in the shaft fixing portion 4 fixed to the case 15 passes. A preset force (for example, by a spring or the like) is applied to the vibration lever 13 so as to be arranged at a position distant from the piezoelectric body 9.

The vibration lever 13 is connected to the body 13 as shown in FIG.
g, a hammer portion 13f, a neck portion 13b, and the like. The vibration lever 13 is integrally formed so that the trunk 13g, the hammer 13f, and the neck 13b are integrated.

An opening 13c is formed on a side surface of the body 13g, and a tapered portion 13e is formed on an inner peripheral surface 13d of the opening 13c. The tapered portion 13e is formed so as to increase in thickness from the hammer portion 13f toward the hole 13a, and the inner peripheral surface 13d is formed at the point where the thickness is the largest.
The shape is cut so as to be substantially perpendicular to. Since the tapered portion 13e has such a configuration, the user can rotate the crown 7 only in a certain direction. The tapered surface 13e comes into contact with the projection 23d of the cam 23 as shown in FIG. A hole 13a is formed in the body 13g so that the shaft 4a through which the vibration lever 13 vibrates and rotates can be penetrated.

The hammer portion 13f rotates about a shaft hole 13a provided in the body portion 13g of the vibration lever 13 so that the hammer portion 13f collides with the piezoelectric body 9 and is displaced by the piezoelectric body 9. Is to give.

As shown in FIG. 7A, the tapered surface of the tapered portion 13e of the vibration lever 13 comes into contact with the convex portion 23d of the cam 23 when the cam 23 rotates in the X2 direction. The vibrating lever 13 rotates in the R1 direction about the shaft 4a of FIG.
Lifted in one direction. Further, when the user further rotates the crown 7 in a predetermined direction, the cam 23
Rotates in the X2 direction. Taper portion 13 of vibration lever 13
e is in contact with the convex portion 23d of the cam 23,
As shown in FIG. 7B, the hammer portion 13f rotates in the R2 direction by dropping into the concave portion 23c, and applies vibration to the piezoelectric body 9.

The piezoelectric body 9 is a piezoelectric element that is displaced by vibration or the like when the hammer portion 13f of the vibration lever 13 comes into contact and generates a voltage by the piezoelectric effect of the piezoelectric body 9. The piezoelectric body 9 has, for example, a disk (substantially cylindrical) shape, and is partially fixed by the fixing portion 11. Piezoelectric body 9
Are provided with the electrodes 20e and 20f (20) of FIG. 7A, for example, one by one in the direction in which the piezoelectric body 9 is displaced. The electrode 20 is made of a metal such as gold (the base is made of Cr, Ni, Ti, or the like), silver, or aluminum. Details of the vicinity of the piezoelectric body 9 will be described later.

The fixing portion 11 is a part of the case 15 and has a projection 11a, a base 11b, and the like. The protruding portion 11a has a triangular pointed protruding shape as shown in FIG. 3 for fixing the piezoelectric body 9 from the base portion 11b, which is the bottom portion of the case 15. Projection 11a
The piezoelectric body 9 is adhered to the tip of the substrate by, for example, an adhesive. The protrusion 11a fixes the node when the piezoelectric body 9 vibrates, and fixes the piezoelectric body 9 so that the antinode of the piezoelectric body 9 can vibrate.

The outline of the configuration of the piezoelectric generator 1 has been described above, and the operation thereof will be briefly described.

When the user rotates the crown 7, the gear 17 rotating via the shaft 7a rotates. The gear 17 rotates the cam 23 in the X2 direction in FIG. 7A via the gear 19, the gear 19a, the speed increasing gear 21, and the gear 23a as described above. When the cam 23 rotates in the X2 direction, the tapered portion 13e formed on the cam 23 comes into contact with the projection 23d of the cam 23. When the cam 23 further rotates in the X2 direction, the protrusion 23d pushes up the taper portion 13e in FIG. 7A, thereby pushing up the hammer portion 13f of the vibration lever 13 in the R1 direction. When the user rotates the crown 7 further, the cam 23 rotates in the X2 direction, and the tapered portion 13e becomes the cam 23 as shown in FIG.
In the recess 23c. The hammer 13f is shown in FIG.
In the R2 direction, and strikes the antinode of the piezoelectric body 9. In this way, the piezoelectric body 9 is vibrated. The piezoelectric body 9 is
The piezoelectric effect converts mechanical energy due to vibration into electrical energy. The output of the converted electric energy is taken out by an electrode 20 or the like provided on the surface of the piezoelectric body 9. The output is rectified by the rectifier circuit 12 of FIG. The power of the charging unit 14 is consumed by the driving unit 16 and the like. In this way,
When the vibration lever 13 repeatedly vibrates the piezoelectric body 9, the piezoelectric power generation device 1 generates power.

FIG. 8 is a cross-sectional view showing an example of a cross section of a piezoelectric body which is a part of the piezoelectric power generating device according to the first embodiment of the present invention.

The piezoelectric body 9 has, for example, a disk shape and is fixed by a fixing portion 11 provided on a part of the case 15. The piezoelectric body 9 is adhered by, for example, an adhesive or the like to the tip of the abutting portion 11a formed or arranged in a circular shape, for example, in the vicinity of the circular node 9a when the piezoelectric body 9 vibrates. .

The feature of the shape of the fixed portion 11 in the piezoelectric power generating device 1 is that the thickness t2 of the base portion 11b of the fixed portion 11 in the direction R in which the vibration lever 13 rotates to apply vibration to the piezoelectric body 9 is determined by the case. The entire bottom surface of the piezoelectric body 9
Is larger than the thickness t1 of Thickness t of base part 11b
The thickness ratio between the thickness t1 of the piezoelectric member 9 and the thickness t1 of the base portion 11b with respect to the thickness t1 of the piezoelectric member 9 as shown in FIG.
Is 1.4 times or more, the distribution ratio ηmod in the piezoelectric power generator 1 becomes 95% or more, and the power generation efficiency is good.

The reason why the thickness t2 of the base portion 11b is larger than the thickness t1 of the piezoelectric body 9 in the piezoelectric power generating device 1 is that the piezoelectric body 9 is vibrated by the vibrating lever 13 when the piezoelectric body 9 is vibrated. Vibration frequency and base part 11 of fixed part 11
This is to prevent the vibration frequency due to unnecessary vibration (hereinafter referred to as spurious) of b from resonating. That is, the piezoelectric power generation device 1 is configured so that the resonance frequency of the piezoelectric body 9 and the resonance frequency of the fixed portion 11 are separated from each other. Thus, when the piezoelectric body 9 is vibrated by the vibrating lever 13, the energy of the vibrating vibrating lever 13 applied to the piezoelectric body 9 is canceled out by the resonance of the fixed portion 11, and the power generation efficiency is reduced. It is possible to prevent the situation from being caused. Therefore, the vibration lever 13 can efficiently transmit the energy generated when the vibration is applied to the piezoelectric body 9 to the piezoelectric body 9.

As shown in FIG. 12, the vibrating lever 13 rotates and the fixed portion 11 in the direction R in which the piezoelectric body 9 vibrates.
Even if the thickness t2 of the base portion 11b is thicker than the thickness t1 of the piezoelectric body 9 in a part of the base portion 11b, resonance can be prevented. Also, as described above, the base portion 11b
Is only required to be thicker than the thickness t1 of the piezoelectric body 9, so that the space can be effectively utilized.

The piezoelectric body 9 in the piezoelectric power generating device 1 is arranged at a position deviated from the vicinity of the center of the circular base portion 11b as the antinode of large amplitude, for example. Further, preferably, the piezoelectric body 9 is
It is better to be arranged in the vicinity of the node 25a when vibrates.
This is because when the vibration lever 13 applies vibration to the piezoelectric body 9, even if a small spurious is generated in the base portion 11 b, the influence on the displacement of the piezoelectric body 9 is small near the node 25 a.

As a method for preventing the vibration of the base portion 11b itself, there is a method in which the planar shape of the base portion 11b is a polygon as shown in FIG. With such a configuration, the piezoelectric power generating device 1 can prevent the base portion 11b from being spurious when the vibration lever 13 is rotated to apply vibration to the piezoelectric body 9.

As described above, the piezoelectric generator 1 is
By adopting such a configuration, spurious is prevented and the distribution ratio ηmod is improved, so that the power generation efficiency can be improved.

Embodiment 2 FIG. 13 is an enlarged sectional view showing an example of a section near a piezoelectric body which is a part of a piezoelectric power generating device according to a second embodiment of the present invention.

The configuration of the piezoelectric generator 1 shown in FIG. 13 is substantially the same as that of the first embodiment. In the piezoelectric power generating device 1 of FIG. 13, a vibration preventing column 40 for preventing spurious of the base portion 11 b when the vibration lever 13 of FIG. 8 rotates and applies vibration to the piezoelectric body 9 is provided. The points are different. The vibration prevention column 40 is, for example, a columnar column. The anti-vibration column 40 is provided around the piezoelectric body 9 in a direction in which the base portion 11b will cause spurious, one of which is fixed to the fixed portion 1
One base part 11b and the other are fixed so as to contact the dial 6 and the like. Therefore, in the piezoelectric power generating device 1 having such a configuration, when the vibration lever 13 rotates to apply vibration to the piezoelectric body 9, the vibration applied to the piezoelectric body 9 is applied to the base portion 11 b.
Even if spurious noise is likely to occur due to the vibration, the vibration preventing column 40 is fixed to the dial 6 and the like firmly fixed to the case 15, so that spurious noise of the base portion 11b can be prevented. . As described above, according to the configuration of the piezoelectric power generating device 1 of FIG. 13, spurious can be prevented, the distribution ratio ηmod can be improved, and the power generation efficiency can be improved.

Embodiment 3 FIG. 14 is an enlarged sectional view showing an example of a section near a piezoelectric body which is a part of a piezoelectric power generating device according to a third embodiment of the present invention.

The configuration of the piezoelectric generator 1 of FIG. 14 is substantially the same as that of the first embodiment. 14 differs from the piezoelectric power generating device 1 in that a curved portion 11c having a curved section in the vicinity of the piezoelectric body 9, for example, is formed in a part of the base portion 11b in the fixed portion 11. In the piezoelectric power generating device 1 of FIG. 14, a curved portion 11 c which is not planar and easily causes such spurious is formed on the base portion 11 b of the fixed portion 11. Accordingly, in the piezoelectric power generating device 1, when the vibration lever 13 shown in FIG. 8 is rotated to apply vibration to the piezoelectric body 9, the base portion 11b resonates with the vibration of the piezoelectric body 9 to prevent spurious. it can. Therefore, the piezoelectric power generating device 1 of FIG.
The distribution ratio ηmod is improved, and the power generation efficiency can be improved.

By mounting the piezoelectric power generating device as the above-described embodiment on a portable device, the user does not need to replace the battery or the like because of its small size and high power generation efficiency.

The present invention is not limited to the above embodiment, and various changes can be made without departing from the scope of the claims.

For example, in the piezoelectric power generating apparatus 1, the energy to be applied to the piezoelectric body 9 by the excitation lever 13 uses the rotation of the crown 7, but the rotation of the rotary weight may be used.

[0061]

According to the first aspect of the present invention, the resonance frequency of the piezoelectric body is separated from the resonance frequency of the fixing means, so that the fixing means hardly generates unnecessary vibration when the piezoelectric body is vibrated. For this reason, the vibrating means can transmit more energy to the piezoelectric body when vibrating the piezoelectric body. Therefore, in the piezoelectric generator, the distribution ratio ηmod
And power generation efficiency can be improved.

According to the second aspect of the present invention, by separating the resonance frequency of the piezoelectric body from the resonance frequency of the fixing means,
Unnecessary vibration is less likely to occur when the fixing member vibrates the piezoelectric body. For this reason, the vibrating means can transmit more energy to the piezoelectric body when vibrating the piezoelectric body. Therefore, in the piezoelectric power generation device, the distribution ratio ηmod can be improved, and the power generation efficiency can be improved. Also,
Since only a part of the base of the fixing means needs to be thick, the space can be effectively used.

According to the third and fourth aspects of the present invention, unnecessary vibration of the fixing means is prevented, and the power generation efficiency of the piezoelectric power generator can be improved.

According to the fourth aspect of the present invention, since the piezoelectric body is not affected by unnecessary vibration, the power generation efficiency of the piezoelectric power generation device can be improved.

According to the fifth, sixth and seventh aspects of the present invention,
Since unnecessary vibration of the fixing means is prevented,
The power generation efficiency of the piezoelectric power generation device can be improved.

According to the eighth aspect of the present invention, since a hard material is used for the fixing means, the resonance frequency of the fixing means is increased. For this reason, if the resonance frequency of the fixing means and the resonance frequency of the piezoelectric body are separated, the frequency is separated and resonance hardly occurs.
Therefore, the power generation efficiency of the piezoelectric power generation device can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of the internal configuration of a portable device equipped with a piezoelectric power generating device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an example of the appearance of a portable device equipped with the piezoelectric power generating device of FIG.

3 is a sectional view of the wristwatch shown in FIG. 2 taken along line A-A '.

FIG. 4 is a plan view of the wristwatch of FIG. 3 when viewed from an I direction.

FIG. 5 is a perspective view of the wristwatch of FIG. 4;

FIG. 6 is an enlarged plan view of the vibration lever of FIG. 1;

FIG. 7 is a diagram showing an operation example of the vibration lever of FIG. 1;

FIG. 8 is an enlarged sectional view showing the vicinity of the piezoelectric body in FIG.

FIG. 9 is a perspective view showing an arrangement example of the piezoelectric body of FIG. 1 on a substrate 22;

FIG. 10 is a perspective view showing an example of the shape of the substrate 22 of FIG. 1;

FIG. 11 is a diagram showing an example of power generation efficiency characteristics of the piezoelectric body of FIG.

FIG. 12 is an enlarged sectional view showing the vicinity of a piezoelectric body of a piezoelectric power generating device according to a second embodiment of the present invention.

FIG. 13 is an enlarged sectional view showing the vicinity of a piezoelectric body of a piezoelectric power generating device according to a third embodiment of the present invention.

FIG. 14 is an enlarged sectional view showing the vicinity of a piezoelectric body of a piezoelectric power generating device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric generator 2 Wristwatch (portable apparatus) 9 Piezoelectric body 11 Fixed part (fixing means) 11a Contact part 11b Substrate (base part) 13 Lever (vibration means)

Claims (8)

[Claims] 1. A piezoelectric body for generating power using a piezoelectric effect, a vibrating means for applying vibration to the piezoelectric body, and a part of the piezoelectric body fixed so that the piezoelectric body can vibrate. A contacting portion that contacts the piezoelectric body when the contacting portion is formed, and fixing means having a base portion on which the contacting portion is formed and serves as a base for the contacting portion. A thickness of the base portion in a direction in which the piezoelectric element is provided is larger than a thickness of the piezoelectric body. 2. The piezoelectric power generating apparatus according to claim 1, wherein a thickness of the base portion in a direction in which the vibrating means applies vibration is partially thicker than a thickness of the piezoelectric body. 3. The piezoelectric power generation device according to claim 1, wherein the piezoelectric body is disposed at a position eccentric from a center of the base in a plane direction of the substantially flat base. 4. The piezoelectric power generating device according to claim 3, wherein the piezoelectric body is disposed at a node where no displacement occurs when the base portion vibrates. 5. The piezoelectric power generating device according to claim 1, wherein a cross-sectional shape of the base portion is curved. 6. The piezoelectric power generator according to claim 1, wherein an outer peripheral shape of the base portion is a polygon. 7. A method according to claim 1, wherein said base portion is provided with a columnar vibration preventing means for preventing vibration of said fixing means when said piezoelectric means is applied to said piezoelectric body by said vibrating means. 7. The piezoelectric generator according to any one of 6. 8. The piezoelectric power generating device according to claim 1, wherein said fixing means is made of a hard material.