JP2014225576A - Piezoelectric type vibration power generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric type vibration power generating device capable of adding an exciting force without being restricted by durability with respect to deformation of a piezoelectric substance.SOLUTION: A piezoelectric type vibration power generating device 10 includes a plate piece 12 which is extended in a cantilever state while being fixed to a support part 16 and in which a width W1 on a fixed end 12k side is smaller than a width 2 on a free end 12J side or equal thereto; and a piezoelectric substance 14 which is mounted on the plate piece 12 and generates power by distortion generated by being deformed together with the plate piece 12 when the plate piece 12 receives an exciting force or forcible displacement.

Description

  The present invention relates to a piezoelectric vibration power generator.

Conventionally, generation of vibration energy using a piezoelectric element has been promoted. As vibration energy, vibration generated by various factors such as human movement, equipment, road traffic, construction work, wind, earthquake and the like is widely targeted.
For example, Patent Document 1 discloses a power generation device in which a vibrating piece has a cantilever structure.

Patent Document 1 has a cantilever-like vibrating piece with a fixed end fixed, and the free end is vibrated by a drive system. The resonator element is formed of a piezoelectric body composed of a lithium niobate single crystal substrate, and electrodes for extracting an electromotive voltage are provided on the upper and lower surfaces of the piezoelectric body. The piezoelectric body is polarized without an adhesive layer, and forms a bimorph vibrating piece without an adhesive layer by an inversion polarization layer or direct bonding. As a result, the free end is vibrated in conjunction with human movement and the like, and power is generated with vibrational energy.

Japanese Patent Laid-Open No. 9-182465

However, in the power generation apparatus of Patent Document 1, the piezoelectric body constitutes a vibrating piece, and the magnitude of the excitation force that can be received by the free end or the magnitude of the forced displacement is the durability against deformation of the piezoelectric body. Constrained by
In view of the above facts, an object of the present invention is to provide a piezoelectric vibration power generator that receives an excitation force or a forced displacement without being restricted by durability against deformation of a piezoelectric body.

  The piezoelectric vibration power generating device according to the invention of claim 1 is fixed to a support portion and projects in a cantilevered manner, and a plate piece having a fixed end side width smaller than or equal to a free end side width, And a piezoelectric body that is attached to the plate piece and generates electric power when the plate piece is subjected to an excitation force or is forcibly displaced and is deformed together with the plate piece to generate distortion.

According to the first aspect of the present invention, the excitation force or forced displacement due to vibration is applied to the piezoelectric body through the plate piece. Thereby, it is not restrict | limited to the durability with respect to a deformation | transformation of a piezoelectric material, but can receive an excitation force or a forced displacement. Further, the plate piece of the present invention has a width on the fixed end side smaller than or equal to a width on the free end side. As a result, the plate piece of the present invention is more distorted than the plate piece having a triangular shape in plan view and a width on the fixed end side larger than the width on the free end side, thereby increasing the power generation efficiency of the piezoelectric body attached to the plate piece. be able to.
This strain characteristic can be obtained both when the weight is fixed to the free end and the support is vibrated or forcedly displaced, and when the weight is fixed to the free end and the free end is vibrated or forcedly displaced. Can do. Furthermore, it is possible to obtain either the case where the support portion is vibrated or forcedly displaced without providing the weight on the free end side, or the case where the free end is vibrated or forcedly displaced without providing the weight on the free end side.

According to a second aspect of the present invention, in the piezoelectric vibration power generator according to the first aspect, the piezoelectric body is attached to the fixed end side of the plate piece.
The amount of distortion of the cantilever plate is larger on the fixed end side than on the free end side. That is, by attaching the piezoelectric body to the fixed end side of the plate piece, the amount of distortion of the piezoelectric body can be increased and the amount of power generation of the piezoelectric body can be increased.

  According to a third aspect of the present invention, in the piezoelectric vibration power generator according to the first or second aspect, the piezoelectric body includes support pieces attached to the plate pieces at a predetermined interval in a longitudinal direction of the plate pieces. The piezoelectric material is bridged over the support piece.

  According to the third aspect of the invention, the piezoelectric body is attached by being separated from the surface of the plate piece by a predetermined distance by the support piece. Thereby, the strain amount of the piezoelectric body can be made larger than the strain amount of the plate piece. As a result, the necessary power generation amount can be obtained from a small deformation of the plate piece.

  According to a fourth aspect of the present invention, in the piezoelectric vibration power generator according to any one of the first to third aspects, the piezoelectric body includes a ceramic sheet formed by bonding rod-shaped piezoelectric ceramics into a sheet shape; And a polyimide film having electrodes printed on both surfaces of the ceramic sheet, and the piezoelectric ceramic sheet and the polyimide film are bonded with an epoxy resin.

  According to the fourth aspect of the present invention, the piezoelectric body is a film-type piezoelectric ceramic (Piezocomposite, piezoelectric composite, or MFC). That is, since the film-type piezoelectric ceramic is formed in a sheet shape, even if the surface of the plate piece is not flat but curved, it can be bonded along the curved surface. Further, since the degree of freedom of bending deformation in the thickness direction is large, even if the plate piece is greatly deformed, it can follow the plate piece without damage.

According to a fifth aspect of the present invention, in the piezoelectric vibration power generation device according to any one of the first to fourth aspects, the plate piece is formed asymmetrically in a plan view. .
Thereby, the deformation | transformation and torsional deformation of the plate piece at the time of vibration can be effectively utilized for power generation.

  Since the present invention is configured as described above, it is possible to provide a piezoelectric vibration power generator that receives an excitation force or a forced displacement without being restricted by durability against deformation of the piezoelectric body.

(A) is a top view which shows the basic composition of the piezoelectric vibration electric power generating apparatus which concerns on 1st Embodiment of this invention, (B) is the side view. (A) is an exploded perspective view showing a basic configuration of a membrane-type piezoelectric ceramic used in the piezoelectric vibration power generator of the present invention, (B) is a side view thereof, and (C) is a plan view thereof. . It is a figure which shows the electrical property of the film | membrane type piezoelectric ceramics used with the piezoelectric type vibration electric power generating apparatus of this invention. (A) is a perspective view of a distortion characteristic simulation model of a plate piece used in the piezoelectric vibration power generator according to the first embodiment of the present invention, and (B1) to (B6) of (B) are plate pieces. It is a perspective view. (A) is a perspective view which shows the simulation conditions of the board | plate material shown to (B1) of FIG. 4, (B), (C) is a characteristic view which shows the simulation result. (A) is a perspective view which shows the simulation conditions of the board | plate material shown to (B2) of FIG. 4, (B), (C) is a characteristic view which shows the simulation result. (A) is a perspective view which shows the simulation conditions of the board | plate material shown to (B3) of FIG. 4, (B), (C) is a characteristic view which shows the simulation result. (A) is a perspective view which shows the simulation conditions of the board | plate material shown to (B5) of FIG. 4, (B), (C) is a characteristic view which shows the simulation result. Both (A) and (B) are characteristic diagrams summarizing the simulation results of the piezoelectric vibration power generator according to the first embodiment of the present invention. (A) is a top view which shows the expansion example of the piezoelectric vibration electric power generating apparatus which concerns on 1st Embodiment of this invention, (B) is the side view, (C) is a plane which shows another expansion example. It is a figure and (D) is a side view which shows the other example of an expansion | deployment. (A) is a perspective view which shows the external appearance of the board | plate material of the piezoelectric vibration power generator which concerns on 2nd Embodiment of this invention, (B), (C) is a characteristic view which shows the simulation result. (A) is a top view which shows the basic composition of the piezoelectric vibration electric power generating apparatus which concerns on 3rd Embodiment of this invention, (B) is the side view. (A) is a perspective view which shows the external appearance of the board | plate material of the piezoelectric type vibration electric power generating apparatus which concerns on 3rd Embodiment of this invention, (B), (C) is a characteristic view which shows the simulation result. (A) is a perspective view which shows the external appearance of the board | plate material of the piezoelectric vibration electric power generating apparatus which concerns on 4th embodiment of this invention, (B) is the side view, (C), (D) is a board | plate material. It is a side view at the time of making it deform | transform. (A) is a perspective view which shows the other example of expansion | deployment of the piezoelectric vibration electric power generating apparatus which concerns on 4th Embodiment of this invention, (B) is the side view, (C), (D) is a board | plate material It is a side view at the time of deforming. (A) is a side view which shows the basic composition of the piezoelectric vibration power generation device which concerns on 5th Embodiment of this invention, (B), (C) is a side view at the time of deform | transforming a board | plate material. (A) is a top view which shows the basic composition of the piezoelectric vibration power generator concerning 6th Embodiment of this invention, (B) is the side view, (C) is a top view which shows an example of an expansion | deployment. And (D) is a plan view showing another development example. (A) is a side plan view showing another example of development of a piezoelectric vibration power generator according to the sixth embodiment of the present invention, and (B) is a perspective view showing another example of development.

(First embodiment)
As shown in the plan view of FIG. 1A and the side view of FIG. 1B, the piezoelectric vibration power generation apparatus 10 according to the first embodiment is stretched from the fixed portion 16 in a cantilever manner with a length LB. It has the vibrating piece 12 that has been put out. The resonator element 12 is formed of a steel flat plate having a plate thickness T1, and is bilaterally symmetric with respect to the center line C1 in plan view. The vibrating piece 12 is fixed to the fixing portion 16 by fixing means (not shown). At this time, the width W1 of the fixed end 12K is made smaller than the width W2 of the free end 12J, and the planar shape changes linearly between the fixed end 12K and the free end 12J of the resonator element 12.

  The vibration piece 12 is deformed in the direction of the arrow F when the fixed portion 16 receives the excitation force P of the plate thickness method (in the direction of the arrow) or when it is subjected to forced displacement. Similarly, even if the free end 12J receives an excitation force of the plate thickness method, it is deformed in the direction of arrow F. Here, the ratio r (r = W1 / W2) between the width W1 of the fixed end 12K and the width W2 of the free end 12J can be about 0.5 (r≈0.5). By making the resonator element 12 have such an inverted trapezoidal shape, as will be described later, the amount of strain in the range (fixed end side) of the resonator element 12 that is a cantilever beam close to the fixed end 12K is, for example, The width W1 of the fixed end 12K can be larger than the strain amount at the same position of the resonator element that is larger than the width W2 of the free end 12J.

A film-type piezoelectric ceramic (piezocomposite, piezoelectric composite, or MFC) 14 is attached to the surface of the vibrating piece 12 (shaded portion). As will be described later, the film-type piezoelectric ceramic 14 is a piezoelectric body that generates a voltage proportional to the amount of strain when strain is generated, and is formed into a rectangle having a width WA and a length LA. It is partially pasted at a position close to the fixed end 12K (distance L1 from the fixed end <distance L2 from the free end).
The film-type piezoelectric ceramic 14 is formed symmetrically in plan view with respect to the center line C <b> 1 of the vibrating piece 12 and is attached to the surface of the vibrating piece 12. As a result, it deforms integrally with the resonator element 12, and generates electric power according to the amount of distortion as the resonator element 12 is deformed. The generated electric power is taken out by the lead wire 122 and can be used via a rectifier circuit or a storage circuit (not shown).

With this configuration, the excitation force P or forced displacement applied to the vibrating piece 12 is applied to the film-type piezoelectric ceramic 14 via the vibrating piece 12. Thus, the vibration force P is not directly applied to the film type piezoelectric ceramic 14, and the deformation amount (strain amount) of the film type piezoelectric ceramic 14 is adjusted by adjusting the durability against the deformation of the vibrating piece 12. can do.
The width of the resonator element 12 of the present invention is such that the width W1 of the fixed end 12K is smaller than the width W2 of the free end 12J. Thus, as will be described later, for example, when the free end 12J is vibrated with the same plate thickness T1 and the same overhang length LB, the plan view is a triangle, and the width W1 of the fixed end 12K is greater than the width W2 of the free end 12J. It is distorted more than a large triangular plate. As a result, even if the excitation force is small, it is possible to generate a larger amount of generated power, and vibrations necessary for power generation by the film-type piezoelectric ceramic 14 can be ensured in a wide range.
This distortion characteristic is the same when the weight is fixed to the free end 12J and the support portion 16 is vibrated.
Further, since the vicinity of the fixed end 12K is distorted more greatly than the vicinity of the free end 12J, the strain amount of the film type piezoelectric ceramic 14 can be increased by attaching the film type piezoelectric ceramic 14 near the fixed end 12K. . As a result, the amount of distortion necessary for power generation can be ensured even with a small excitation force P or forced displacement. Alternatively, an equivalent generated power can be obtained with the film-type piezoelectric ceramic 14 having a smaller area.

Next, the film type piezoelectric ceramic 14 will be described.
As shown in the perspective view of FIG. 2A, the film-type piezoelectric ceramic (Piezocomposite, piezoelectric composite, or MFC) 14 is formed by arranging rod-shaped piezoelectric ceramics 128 in a row and bonding them with an epoxy resin 126 sandwiched therebetween. A ceramic sheet 127 having a sheet shape is provided. A polyimide film 124 on which an electrode 125 is printed is disposed on both surfaces of the ceramic sheet 127, and the ceramic sheet 127 and the polyimide film 124 are joined by an epoxy resin 126. . Thereby, a sheet-like piezoelectric body (film-type piezoelectric ceramic) is formed.

As shown in the side view of FIG. 2B and the plan view of FIG. 2C, one surface of the film-type piezoelectric ceramic 14 is attached to the surface of the vibrating piece 12, and is integrated with the vibrating piece 12. It can be deformed. In addition, a lead wire 122 is attached to the electrode 125 of the film type piezoelectric ceramic 14 to output electric power generated by the film type piezoelectric ceramic 14.
With this configuration, when the resonator element 12 is deformed in the direction of the arrow Q by receiving an excitation force at the fixed end 12K or the free end 12J, and the film-type piezoelectric ceramic 14 is distorted, the film-type piezoelectric ceramic 14 Generates power proportional to the amount of distortion. The film-type piezoelectric ceramic 14 has a thin film shape and can provide a compact power generator.
In addition, since the film-type piezoelectric ceramic is formed in a sheet shape, it can be bonded along a curved surface even if the surface of the vibrating piece 12 is not flat but curved. In addition, since the degree of freedom of bending deformation in the thickness direction is large, even if the vibration piece 12 is greatly deformed, it can follow the plate piece without damage.

  Further, when a voltage is applied to the both sides of the piezoelectric ceramic 128 via the lead wires 122, the film-type piezoelectric ceramic 14 is distorted according to the applied voltage in the piezoelectric ceramic 128. Deform in the direction of arrow Q. As a result, by simultaneously applying the same applied voltage to the film-type piezoelectric ceramics 14 on both sides of the vibrating piece 12, the vibrating piece 12 can be expanded and contracted from both sides in the direction of the arrow Q. That is, by fixing to the vibrating piece 12, it is possible to function as an actuator that expands and contracts the vibrating piece 12 according to the applied voltage.

FIG. 3 is a characteristic diagram showing an example of the relationship between the applied voltage and the generated output. The horizontal axis is the applied voltage (V), and the vertical axis is the generated output (N). The piezoelectric vibration power generation apparatus 10 used in the experiment has a configuration in which film-type piezoelectric ceramics 14 are fixed to both surfaces of a vibration piece (substrate) 12 having a thickness of 0.4 mm, and an applied voltage (V) and generated output ( The relationship of N) was measured.
As shown by the characteristic PV, the experimental result shows that the characteristic PV is almost linear in the range where the applied voltage (V) is positive (particularly the tensile side of the steel plate), and the generated output proportional to the applied voltage (V) ( It can be seen that N) is obtained. This characteristic shows the same tendency when the film-type piezoelectric ceramic 14 is functioned as a power generation device that generates electric power according to the amount of strain. Therefore, this characteristic occurs when the vibrating piece 12 is vibrated by applying an excitation force. Electric power can be generated according to the amount of strain.

Next, the relationship between the shape of the resonator element 12, the amount of distortion, and the amount of power generation will be described based on simulation results.
FIG. 4A shows a simulation model. The fixed end 12K of the resonator element 12 is fixed to the fixed portion 16, and a weight 20 is attached to the free end 12J protruding with a length LB. In the simulation, an excitation force 18 in the arrow direction (Z-axis direction) was applied to the fixed portion 16. As the excitation force 18, a pulse wave having a frequency component of 10N was input.

The simulation was performed for six types of vibrating pieces 56, 57, 58, 30, 12, and 26 having different shapes shown in the perspective views of (B1) to (B6) of FIG.
4B1 has a shape in which the width W1 is the same as the width W2, and the plate thickness Tx is changed in the length direction along a quadratic curve having a constant amount of strain. 4B2 has a shape in which the plate thickness T1 is constant, the fixed portion 16 has a width W1, and the width Wx is changed to a triangular shape with a constant strain along the length direction. . 4 (B3) has a trapezoidal shape with a constant plate thickness T1, a part of the triangular tip cut off, and a width W1 on the fixed end side wider than a width W2 on the free end side. The vibrating piece 12 of FIG. 4 (B5) is the vibrating piece 12 of the present embodiment, and is changed to an inverted trapezoidal shape having a constant plate thickness T1 and a wider width W2 on the free end side than the width W1 on the fixed end side. It was.
Note that FIG. 4 (B4) will be described in the third embodiment, and FIG. 4 (B6) will be described in the second embodiment.

In the simulation, the overhang lengths LB of the four types of vibration pieces 56, 57, 58, and 12 are all LB = 50 mm, and the volume V is constant at V = 1000 mm ³ . The attenuation constant was 2%, and the weight of the weight was 1 kg (12.5 × 50 × 100 mm iron). The weight was modeled as a mass load at one center of the tip. Note that the weight is not shown in FIGS. 4B1 to 4B6. Further, the width dimension W of the resonator elements 56, 57, 58, and 12 was adjusted so that the primary natural frequency of the mass system was uniform at 20 Hz.

FIG. 5 shows a simulation result in the resonator element 56 of FIG. 5A shows the coordinate axis and the vibration position of the vibrating piece 56, FIG. 5B shows the amount of distortion in the length direction (X direction) of the vibrating piece 56, and FIG. The calculated value of the square of the amount of distortion contributing to the amount of generated power is shown.
FIG. 5B shows the results when the widths W1 and W2 of the resonator element 56 are 18.9 mm, and the thickness TK of the fixed end 56K is 1.588 mm. The distortion amount characteristic U is obtained in the length direction. In the examined range (LB = 50 mm), the value is almost constant (3 × 10 ⁻³ ). Further, from FIG. 5C, the calculated value V of the square of the distortion amount contributing to the generated power amount was also a substantially constant value (1 × 10 ⁻⁵ ) in the length direction.
From this result, it can be said that in the shape of the resonator element 56, almost the same power generation amount can be obtained regardless of the position where the membrane-type piezoelectric ceramic 14 is attached.

FIG. 6 shows a simulation result in the resonator element 57 of FIG. 6A shows the coordinate axis and vibration position of the vibrating piece 57, FIG. 6B shows the amount of distortion in the length direction (X direction) of the vibrating piece 57, and FIG. The calculated value of the square of the amount of distortion contributing to the amount of generated power is shown.
FIG. 6B shows the result when the plate thickness T1 of the resonator element 57 is 1.205 mm and the width W1 is 33.2 mm. The distortion amount characteristic U is a range examined in the length direction (LB = 50 mm), which is a substantially constant value (3 × 10 ⁻³ ). In addition, from FIG. 6C, the calculated value of the square of the distortion amount contributing to the generated power amount is also a substantially constant value (1 × 10 ⁻⁵ ) in the length direction.
From this result, it can be said that the same power generation amount can be obtained regardless of the position of the membrane-type piezoelectric ceramic 14 in the shape of the resonator element 57.

FIG. 7 shows a simulation result in the resonator element 58 of FIG. 4 (B3). 7A shows the coordinate axis and the vibration position of the vibrating piece 58, FIG. 7B shows the amount of distortion in the length direction (X direction) of the vibrating piece 58, and FIG. The calculated value of the square of the amount of distortion contributing to the amount of generated power is shown.
FIG. 7B shows the result when the plate thickness T1 of the resonator element 58 is 1.226 mm and the width W1 is 27.2 mm. The distortion amount characteristic U is large at the fixed end 58K in the length direction ( About 4 × 10 ⁻³ ) and small at the free end 58J (about 0.5 × 10 ⁻³ ). From FIG. 7C, the calculated value V of the square of the distortion amount contributing to the generated power amount is also The same trend. That is, the fixed end 58K is large (about 1.5 × 10 ⁻⁵ ) and the free end 58J is small (about 0.1 × 10 ⁻⁵ ).
From this result, in the shape of the vibrating piece 58, if the membrane-type piezoelectric ceramic 14 is attached to the fixed end side, the power generation amount can be larger than that of the vibrating pieces 56 and 57 described above.

FIG. 8 shows a simulation result of the resonator element 12 (the resonator element of the present embodiment) of FIG. 4 (B5). 8A shows the coordinate axis and the vibration position of the resonator element 12, FIG. 8B shows the amount of distortion in the length direction (X direction) of the resonator element 12, and FIG. The calculated value of the square of the amount of distortion contributing to the amount of generated power is shown.
FIG. 8B shows the result when the plate thickness T1 of the resonator element 12 is 1.524 mm, the width W1 is 8.75 mm, and the width W2 is 17.5 mm. The distortion amount characteristic U is the length direction. The fixed end 12K is large (about 7.5 × 10 ⁻³ ) and the free end 12J is small (about 0.0 × 10 ⁻³ ). Further, from FIG. 8C, the calculated value V of the square of the distortion amount contributing to the generated power amount has the same tendency. That is, it is large (about 5.5 × 10 ⁻⁵ ) at the fixed end 12K and small (about 0.0 × 10 ⁻⁵ ) at the free end 12J. From this result, in the shape of the resonator element 12, if the membrane-type piezoelectric ceramic 14 is attached to the fixed end side, the amount of power generation can be made larger than that of the above-described resonator elements 56, 57, and 58.

FIG. 9 shows a summary of the above simulation results.
FIG. 9A shows the power generation efficiency of the vibrating pieces 56, 57, 58, and 12 when the attachment range of the film-type piezoelectric ceramic 14 is set to 2/3 of the extension length LB from the fixed end. , B2, B3, B5. Here, the power generation efficiency was obtained by dividing the calculated value V of the square of the amount of distortion by the plane area of each resonator element. Furthermore, the ratio of the power generation efficiency when the power generation efficiency value of the triangular vibrating piece 56 is 100 is shown.
From the results, it can be seen that the resonator element 12 of the present embodiment is about 1.7 times the triangular resonator element 56 and has higher power generation efficiency than the compared resonator elements 56, 57, and 58.

FIG. 9B shows the power generation efficiency of the resonator elements 56, 57, 58, and 12 when the planar size of the membrane-type piezoelectric ceramic 14 is 8 mm × 16 mm and it is installed at a position where the amount of generated power is maximized. Yes. Here, the power generation efficiency was obtained by dividing the calculated value V of the square of the distortion amount by the plane area of each vibration piece. Furthermore, a comparison is made when the value of the triangular vibrating piece 56 is 100.
From the results, it can be seen that the resonator element 12 of the present embodiment is about 2.7 times the triangular resonator element 56, and the power generation efficiency is large in comparison.
As described above, it can be said that the resonator element 12 of the present embodiment has a shape that can generate power more efficiently than the resonator elements 56, 57, and 58. That is, the power generation efficiency can be maximized within the limited area of the film-type piezoelectric ceramic 14. As a result, it contributes to a reduction in the usage amount of a member such as a piezoelectric material, leading to cost reduction of the piezoelectric vibration power generation apparatus 10.

In the present embodiment, the example in which the film-type piezoelectric ceramic 14 is attached to a part of the resonator element 12 has been described. However, the present invention is not limited to this, and the plan view of FIG. 10A and FIG. As shown in the side view of (), it may be attached in a size that covers the entire area of the resonator element 12. By increasing the area of the film-type piezoelectric ceramic 14, the power generation amount of the piezoelectric vibration power generator 10 can be further increased.
In the present embodiment, the material of the resonator element 12 has been described using a steel flat plate. However, the present invention is not limited to this, and may be formed of other materials such as resin and rubber.
Although not shown in the drawings, in the present embodiment, the film-type piezoelectric ceramic 14 has been described as being attached to both surfaces of the resonator element 12. However, the present invention is not limited to this, and the vibration piece 12 may be attached only to one side. Thereby, although the electric power generation amount of the piezoelectric vibration power generator 10 decreases, the manufacturing cost of the piezoelectric vibration power generator 10 can be reduced.

In the present embodiment, the film-type piezoelectric ceramic 14 has been described as an example of the piezoelectric body. However, it is not limited to this, For example, you may use the piezoelectric ceramics which are not a film type. However, in this case, in order to prevent damage due to deformation of the resonator element 12, it is necessary to pay attention to durability against deformation of the piezoelectric ceramic that is not a film type.
In the present embodiment, the fixed end 12K and the free end 12J are connected by a straight line, and the planar shape of the resonator element 12 is an inverted trapezoid. However, the shape is not limited to this, and the shape shown in the plan view of FIG. That is, it is good also as a shape which connects between the fixed end 13K and the free end 13J with a curve. By adjusting the shape of the curve, it is possible to design the deformation position and the amount of variation in the longitudinal direction of the resonator element 12 in more detail.

In the present embodiment, the case where the weight 20 is attached to the free end 12 </ b> J of the resonator element 12 and the fixed portion 16 is vibrated has been described. However, the present invention is not limited to this, and the same effect can be obtained even when the fixing portion 16 is forcibly displaced. The same effect can be obtained even when the weight 20 is fixed to the free end 12J and the free end 12J is vibrated or forcedly displaced.
Further, when the fixed portion 16 is vibrated or forcibly displaced without providing the weight 20 at the free end 12J, and the free end 12J is vibrated or forcibly displaced with the excitation force P without providing the weight 20 at the free end 12J. In any case, the same effect can be obtained (see FIG. 10D).
As described above, according to the present embodiment, the piezoelectric vibration power generator 10 capable of receiving the excitation force P or the forced displacement without being restricted by the durability against deformation of the membrane piezoelectric ceramic 14 is provided. be able to.

(Second Embodiment)
As shown in the perspective view of FIG. 11 (A), the piezoelectric vibration power generator 24 according to the second embodiment has the vibration described in the first embodiment in that the planar shape of the resonator element 26 changes stepwise. It differs from the piece 12. The difference from the first embodiment will be mainly described.
The vibration piece 26 has a stepped shape in which the width W1 of the fixed end 26K is narrower than the width W2 of the free end 26J, and the change in the width is two steps. That is, the fixed end 26K is formed with a width W1 in the range of the length LB1 in the longitudinal direction, the free end 26J is formed with a width W2 in the range of the length LB3 in the longitudinal direction, and the intermediate portion is long in the longitudinal direction. The width W3 is an intermediate width W3 between the width W1 and the width W2. Here, the length LB1, the length LB2, and the length LB3 are each about 1/3 of the overhang length LB.

FIG. 11B and FIG. 11C show simulation results for the resonator element 26. The simulation conditions are the same as in the first embodiment. Note that this embodiment corresponds to (B6) in FIG. 11A shows the coordinate axis and the vibration position of the vibrating piece 26, FIG. 11B shows the amount of distortion in the length direction (X direction) of the vibrating piece 26, and FIG. The calculated value of the square of the amount of distortion contributing to the amount of generated power is shown.
FIG. 11B shows the results when the plate thickness T1 of the resonator element 12 is 1.61 mm, the width W1 is 8.26 mm, and the width W2 is 16.52 mm. The characteristic U indicating the amount of distortion is a fixed end. It is larger at 26K (about 7.0 × 10 ⁻³ ) and smaller at the tip of the free end 26J (about 0.0 × 10 ⁻³ ). Further, from FIG. 11C, the calculated value V of the square of the distortion amount also has the same tendency as the characteristic U, that is, the largest at the fixed end 26K (about 5.0 × 10 ⁻⁵ ), and the tip of the free end 26J. And the smallest (about 0.0 × 10 ⁻⁵ ). Further, the characteristic U is greatly changed (decreased) in a portion where the planar shape changes stepwise.
When this result is compared with the first embodiment, the vibrating piece 26 of the present embodiment corresponds to the bar graph of the vibrating piece B6 in FIG. 9A and the bar graph of the vibrating piece B6 in FIG. 9B, respectively. From the simulation results of FIGS. 9A and 9B, the vibrating piece 26 of the present embodiment is the vibrating piece 56 described in the first embodiment if the membrane-type piezoelectric ceramic 14 is attached to the fixed end side. , 57, 58, and 12, the power generation efficiency can be increased.
Furthermore, since the vibration piece 26 can be formed by linear processing, processing becomes easy. Other configurations are the same as those of the piezoelectric vibration power generation apparatus 10 according to the first embodiment, and a description thereof will be omitted.

(Third embodiment)
As shown in the plan view of FIG. 12A and the side view of FIG. 12B, the piezoelectric vibration power generation device 28 according to the third embodiment is such that the resonator element 30 is rectangular in plan view. However, it differs from the resonator element 12 described in the first embodiment. The difference from the first embodiment will be mainly described.
The vibration piece 30 has a thickness T in the entire range of the overhang length LB, and the fixed end 30K and the free end 30J have the same width W3. With this configuration, as described in the first embodiment, a larger displacement (amount of strain) can be obtained on the fixed end side than on the free end side.

FIG. 13 shows a simulation result in the resonator element 30. The simulation conditions are the same as in the first embodiment. Note that this embodiment corresponds to (B4) in FIG. 13A shows the coordinate axis and the vibration position of the vibrating piece 30, FIG. 13B shows the amount of distortion in the length direction (X direction) of the vibrating piece 30, and FIG. The calculated value of the square of the amount of distortion contributing to the amount of generated power is shown.
FIG. 13B shows the result when the plate thickness T1 of the resonator element 30 is 1.375 mm and the widths W1 and W3 are 14.5 mm. The characteristic U indicating the amount of distortion is the fixed end 30K in the length direction. (About 5.5 × 10 ⁻³ ) and small at the free end 30J (about 0.0 × 10 ⁻³ ). Further, from FIG. 13C, the calculated value V of the square of the distortion amount also has the same tendency as the characteristic U, that is, large at the fixed end 30K (about 3.2 × 10 ⁻⁵ ) and small at the free end 30J ( About 0.0 × 10 ⁻⁵ ).

  Comparing this result with the first embodiment, the resonator element 30 of this embodiment corresponds to the bar graph of the resonator element B4 in FIG. 9A and the bar graph of the resonator element B4 in FIG. 9B, respectively. From the simulation results of FIG. 9A and FIG. 9B, the resonator element 30 of the present embodiment is the resonator element 12 described in the first embodiment if the membrane-type piezoelectric ceramic 14 is attached to the fixed end side. Although it is smaller than the vibrating piece 26 described in the second embodiment, the power generation efficiency can be made larger than that of the vibrating pieces 56, 57, 58 described in the first embodiment. Other configurations are the same as those of the piezoelectric vibration power generation apparatus 10 according to the first embodiment, and a description thereof will be omitted.

(Fourth embodiment)
As shown in FIG. 14, the piezoelectric vibration power generation apparatus 32 according to the fourth embodiment is the piezoelectric type described in the first embodiment in that the film-type piezoelectric ceramic 14 is attached away from the surface of the vibrating piece 34. It differs from the vibration power generator 10. The difference from the first embodiment will be mainly described.
As shown in the perspective view of FIG. 14A and the side view of FIG. 14B, the vibrating element 34 has a membrane-type piezoelectric ceramic 14 in a direction orthogonal to the center line C1 in the left-right direction in plan view. The support members 36 </ b> A and 36 </ b> B are attached with a predetermined distance in the longitudinal direction of the vibrating piece 34. Each of the support members 36A and 36B is formed at a height H from the surface of the vibrating piece 34, and the film-type piezoelectric ceramic 14 is placed on the upper surfaces of the supporting members 36A and 36B in parallel with the surface of the vibrating piece 34. Has been passed. As a result, the film-type piezoelectric ceramic 14 is attached away from the surface of the vibrating piece 34 by the height H of the support members 36A and 36B.

With this configuration, as shown in the side views of FIGS. 14C and 14D, when the vibration piece 34 is deformed in the direction of the arrow F due to the excitation force P received by the fixing portion 16. The linear length LB2 of the membrane-type piezoelectric ceramic 14 on the side of the vibrating piece 34 that has been deformed into a convex shape can be made larger than the surface length LB1 of the vibrating piece 34. That is, the strain amount of the film-type piezoelectric ceramic 14 can be made larger than the strain amount of the vibrating piece 34.
As a result, even if the excitation force P applied to the fixed portion 16 is small, the amount of distortion necessary for power generation can be secured, and power can be generated in a wide vibration range. As a result, the amount of power generation can be increased. The planar shape of the resonator element 34 may be any of the resonator elements 12, 26, and 30 described in the first to third embodiments. Other configurations are the same as those of the piezoelectric vibration power generation apparatus 10 according to the first embodiment, and a description thereof will be omitted.

As an example of development of this embodiment, as shown in the perspective view of FIG. 15A and the side view of FIG. 15B, the number of support members 36 may be increased and added in the longitudinal direction of the vibrating piece 34. Good.
In FIG. 15, as an example, two support members 36C and 36D are disposed between the support members 36A and 36B in parallel with the support members 36A and 36B.
With this configuration, as shown in the side views of FIGS. 15C and 15D, the fixed portion 16 is vibrated with the exciting force P, and the vibrating piece 34 is deformed in the direction of the arrow F. In this case, the film-type piezoelectric ceramic 14 can be made to follow the deformed shape of the vibrating piece 34 faithfully and be deformed to the length LB2. Thereby, the length LB2 of the film-type piezoelectric ceramic 14 becomes larger than the surface length LB1 of the vibrating piece 34. As a result, the strain amount of the film-type piezoelectric ceramic 14 can be made larger than the strain amount of the vibrating piece 34.

(Fifth embodiment)
As shown in the side view of FIG. 16A, in the piezoelectric vibration power generation apparatus 40 according to the fifth embodiment, the plate thickness T2 of the vibrating piece 42 is equal to the plate thickness T1 of the vibrating piece 12 described in the first embodiment. It differs from the first embodiment in a thicker point. The difference from the first embodiment will be mainly described.
The vibration piece 42 has lower durability against deformation than the vibration piece 12 described in the first embodiment, and the plate thickness T2 is formed of a member larger than the plate thickness T1 of the vibration piece 12. Yes. The planar shape of the resonator element 34 may be any of the resonator elements 12, 26, and 30 described in the first to third embodiments.

With this configuration, as shown in the side views of FIGS. 16B and 16C, when the vibrating piece 42 receives an excitation force in the direction of arrow F at the fixing portion 16, the vibrating piece 42 and the membrane-type piezoelectric ceramic 14 can be deformed along the surface of the vibrating piece 42.
At this time, since the position of the film type piezoelectric ceramic 14 is far away from the center line C2 of the thickness method of the vibrating piece 42, the amount of strain of the film type piezoelectric ceramic 14 is determined as the vibrating piece 12 described in the first embodiment. Compared to the amount of distortion when affixed to, it can be increased. Thereby, power generation can be started with a small excitation force P, and power generation performance can be improved.
Other configurations are the same as those of the piezoelectric vibration power generation apparatus 10 according to the first embodiment, and a description thereof will be omitted.

(Sixth embodiment)
As shown in FIG. 17, the piezoelectric vibration power generator 46 according to the sixth embodiment is different from the resonator element 12 described in the first embodiment in that the resonator element 48 is asymmetrical in plan view. To do. The difference from the first embodiment will be mainly described.
As shown in the plan view of FIG. 17A and the side view of FIG. 17B, the resonator element 48 is the longitudinal direction of the resonator element 48 in plan view and passes through the center of the membrane piezoelectric ceramic 14. It is formed to be asymmetric with respect to the line C3 on the left and right (in the direction orthogonal to the center line C3).
That is, the film-type piezoelectric ceramic 14 is symmetric with respect to the center line C3 in plan view. On the other hand, the vibrating piece 48 has the width W1 of the fixed end 48K smaller than the width W2 of the free end 48J, and the center between the fixed end 48K and the free end 48J is continuous in a straight line. The left and right sides are formed asymmetrically with respect to the passing center line C3.

As a result, for example, when the vibrating piece 48 receives an excitation force at the fixed end 48K, it deforms in the direction of the arrow F while being twisted. Even in this case, the film-type piezoelectric ceramic 14 can be attached to the fixed end 48K so that necessary strain can be obtained, and deformation of the plate piece in the plate thickness direction and torsional deformation during vibration can be effectively performed. It can be used for power generation.
This characteristic is the same even when an excitation force is applied to the free end 48J, and deformation in the thickness direction and torsional deformation of the vibration piece 48 during vibration can be effectively utilized for power generation.

As shown in FIG. 17C, as a modification of the present embodiment, for example, the planar shape of the resonator element 50 is a staircase in plan view between the width W1 of the fixed end 50K and the width W2 of the free end 50J. The vibration piece 50 may be formed asymmetrically with respect to the center line C3 passing through the center of the film-type piezoelectric ceramic 14.
That is, the film-type piezoelectric ceramic 14 is bilaterally symmetric with respect to the center line C3 in a plan view, and the width W1 of the fixed end 50K is smaller than the width W2 of the free end 50J. It may be asymmetric between the fixed end 50K and the free end 50J with respect to C3.

Furthermore, as shown in FIG. 17D, as another modification of the present embodiment, the planar shape of the vibrating piece 54 is, for example, between the width W1 of the fixed end 54K and the width W2 of the free end 54J. The vibration piece 54 may be formed asymmetrically with respect to the center line C3 passing through the center of the film-type piezoelectric ceramic 14 so as to have a curved shape in plan view.
That is, the film-type piezoelectric ceramic 14 is bilaterally symmetric with respect to the center line C3 in a plan view, and the width W1 of the fixed end 54K is smaller than the width W2 of the free end 54J. It may be asymmetric between the fixed end 54K and the free end 54 with respect to C3.

Furthermore, as shown in FIG. 18A, as another modification of the present embodiment, the vibrating piece 62 is asymmetric in the vertical direction in a side view (with respect to the center line C4 drawn horizontally from the fixed end 62K). Asymmetrical in the vertical direction). That is, as shown by the solid line, the vibrating piece 62 is bent upward (convex downward), the excitation force P is applied downward to the free end 62J, and the vibrating piece 62 protrudes upward as shown by the broken line. You may deform | transform into the shape of. Thereby, the film-type piezoelectric ceramic 14 can be deformed along the surface of the vibrating piece 62, and the strain necessary for power generation can be obtained.
The bending direction of the vibrating piece 62 is such that the vibrating piece 62 is bent downward (convex upward), the excitation force P is applied upward to the free end 62J, and the vibrating piece 62 has a convex downward shape. It may be configured to deform.

Further, as shown in FIG. 18B, as another modification of the present embodiment, the vibrating piece 64 is fixed to the fixed end 64K, and the free end 64J is rotated around the center line C5 of the vibrating piece 64. It is good also as the shape made to do. Thereby, it becomes asymmetric with respect to the center line C5 in the left-right direction in plan view, and asymmetric with respect to the center line C5 in the up-down direction in side view. With this configuration, it is possible to apply the excitation force P to the free end 64J and to deform the film type piezoelectric ceramic 14 along the surface of the vibrating piece 64, thereby obtaining the strain necessary for power generation.
Other configurations are the same as those of the piezoelectric vibration power generation apparatus 10 according to the first embodiment, and a description thereof will be omitted.

10, 24, 28, 32, 40, 46 Piezoelectric vibration power generator 12, 26, 30, 34, 42, 48, 50, 52, 54 Vibrating piece (plate piece)
14, 15 Film type piezoelectric ceramics (piezoelectric material)
16 Fixing member (supporting part)
36 Support member (support piece)
124 Polyimide film (membrane type piezoelectric ceramics, piezoelectric body)
125 electrodes (film piezoelectric ceramics, piezoelectric bodies)
126 Epoxy resin (film type piezoelectric ceramics, piezoelectric body)
127 Ceramic sheet (film-type piezoelectric ceramic, piezoelectric body)
128 Piezoelectric ceramics (film piezoelectric ceramics, piezoelectric bodies)

Claims (5)

A plate that is fixed to the support and is cantilevered, the width of the fixed end is smaller than or equal to the width of the free end, and
A piezoelectric body that is attached to the plate piece, and generates electric power by deformation and distortion with the plate piece when the plate piece is subjected to an excitation force or a forced displacement;
A piezoelectric vibration power generator having   The piezoelectric vibration power generator according to claim 1, wherein the piezoelectric body is attached to the fixed end side of the plate piece.   The piezoelectric body includes a support piece attached to the plate piece at a predetermined interval in the longitudinal direction of the plate piece, and the piezoelectric body is bridged over the support piece. Piezoelectric vibration power generator.   The piezoelectric body includes a ceramic sheet formed by bonding rod-shaped piezoelectric ceramics and a polyimide film disposed on both surfaces of the ceramic sheet and having electrodes printed thereon, and the piezoelectric ceramic sheet and the polyimide film are The piezoelectric vibration power generator according to any one of claims 1 to 3, which is a film-type piezoelectric ceramic bonded with an epoxy resin.   5. The piezoelectric vibration power generator according to claim 1, wherein the plate piece is formed to be asymmetrical in a plan view.