JP2015164153A - power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve power generation efficiency of a power generator using a piezoelectric element.SOLUTION: A power generator 2 using a piezoelectric element includes: a face material 20; a support member 22; a buffer member 24; and a piezoelectric film 26. The support member 22 supports the face material 20 such as a glass panel and a wall surface panel. The buffer member 24 is provided between the face material 20 and the support member 22. The piezoelectric film 26 has a power generation function and is provided on a surface of the buffer member 24.

Description

  The present invention relates to a power generator.

  Due to recent demands for energy saving, renewable energy (also called environmental energy) such as light, heat and vibration has been attracting attention, and energy harvesting elements (also called energy harvesting elements) for effectively using them Development is underway. As one of such energy harvesting elements, a piezoelectric element has attracted attention.

  The present inventors examined a power generation device using a piezoelectric element that can be used in buildings such as buildings, factories, and general houses. FIG. 1 is a diagram showing a power generator 1r studied by the present inventors. The power generation device 1r mainly includes a glass 10 and a piezoelectric film 12 having a power generation function. The piezoelectric film 12 is provided on the surface so as to cover the entire surface of the glass 10.

  In the building, the glass 10 vibrates or deforms due to the influence of wind or the like. When the glass 10 is deformed, the piezoelectric film 12 is deformed following the deformation. As a result, electric power can be taken out from the electrode 14 drawn out from the piezoelectric film 12. Note that the power generation device 1r in FIG. 1 should not be recognized as a publicly known technique, but has been independently studied by the present inventors.

Japanese Patent No. 4868475 JP 2013-77646 A Japanese Patent Laid-Open No. 10-173474

  As a result of studying the power generator 1r of FIG. 1, the present inventors have recognized the following problems. The piezoelectric film 12 is expensive regardless of its formation method. Therefore, when the piezoelectric film 12 is formed on the entire surface of the glass 10 as in the power generation device 1r of FIG. 1, the power generation device 1r becomes high. In order to reduce the cost of the power generation device 1r, further improvement in power generation efficiency is desired.

  This invention is made | formed in view of this subject, and one of the exemplary objectives of the certain aspect exists in the improvement of the electric power generation efficiency of an electric power generating apparatus.

  One embodiment of the present invention relates to a power generation device. The power generation device includes a face member, a support member that supports the face member, a buffer member provided between the face member and the support member, and a piezoelectric film having a power generation function provided on the surface of the buffer member.

  When the face material vibrates or deforms due to an external force, the buffer member bears and transmits all the load applied to the face material. Comparing the case in which the piezoelectric film is provided on the buffer member and the case in which the piezoelectric film is widely formed on the face material, when the same external force is applied to the same face material, the strain generated in the piezoelectric film is in the degree of compressive stress. In proportion, the former is much larger. Further, since the longitudinal elastic modulus is different between the support member and the cushioning material, the strain is further increased. Therefore, according to this aspect, the power generation efficiency can be increased. Thereby, the area of the piezoelectric film necessary for generating the same electric power can be reduced, and the power generation device can be reduced in cost. Alternatively, it is possible to increase the power generation amount when the piezoelectric film having the same area is used.

The piezoelectric film may be provided on the surface of the buffer member and in contact with the face material.
In this case, since the force from the face material is directly transmitted to the buffer member, the power generation efficiency can be further increased.

The face material may be supported in a state having play with respect to the buffer member.
In this case, since an impact force is applied from the face material to the piezoelectric film, the power generation efficiency can be further increased.

The piezoelectric film may be formed by coating on the surface of the buffer member.
When a piezoelectric film is affixed to the buffer member, a minute gap is easily formed between them, and this gap is likely to be uneven, and this gap may cause uneven transmission of load from the face material to the piezoelectric film and reduce it. On the other hand, by applying, since the integrity of the buffer member and the piezoelectric film is increased, the load transmission capability is improved, and the power generation efficiency can be increased.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  According to an aspect of the present invention, power generation efficiency can be increased.

It is a figure which shows the electric power generating apparatus which the present inventors examined. It is an external appearance perspective view of the electric power generating apparatus which concerns on embodiment. It is the sectional view on the AA line of the electric power generating apparatus of FIG. It is a disassembled perspective view of a power generator. Fig.5 (a)-(c) is a figure explaining the electric power generation mode of the electric power generating apparatus which concerns on embodiment. It is a figure which shows the generated voltage of the electric power generating apparatus which concerns on embodiment. FIGS. 7A and 7B are plan views showing the comparative technique used for the measurement and the power generation apparatus according to the embodiment, respectively. FIGS. 8A to 8D are cross-sectional views showing a power generation device according to a modification. FIGS. 9A to 9C are cross-sectional views showing a power generator according to another modification. 10A and 10B are cross-sectional views showing a power generation device according to another modification. Fig.11 (a)-(d) is a figure which shows the electric power generating apparatus which concerns on a modification.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  The power generation apparatus according to the embodiment is suitably used for buildings and buildings such as buildings, factories, and general households, and generates power using environmental energy brought about by wind or human walking. More specifically, it is used for (1) locations that receive pressure from wind, such as glass windows, outer wall panels, and roofs, and (2) locations that receive pressure from human walking, such as floors. In this embodiment, a case where it is used for a window glass will be described as an example.

FIG. 2 is an external perspective view of the power generation device 2 according to the embodiment.
The power generation device 2 includes a face member 20, a support member 22, buffer members 24 and 28, and a piezoelectric film 26. In FIG. 2, only the face material 20 and the support member 22 appear. The face material 20 is a glass window. The support member 22 is a frame that supports the face material 20 on its four sides, and corresponds to, for example, a sash. The support member 22 is attached to an opening 52 provided on the wall surface 50 of the building.

  3 is a cross-sectional view taken along line AA of the power generation device 2 of FIG. The buffer members 24 and 28 are provided between the face material 20 and the support member 22. The buffer members 24 and 28 are elastic bodies such as rubber, and can be gaskets, glazing channels, glazing beads, sealing materials, or packing, depending on their functions.

  The support member 22 includes a first portion 22a, a second portion 22b, and a connecting means 22c such as a screw or a fitting for connecting them. The support member 22 may be integrally formed.

  The piezoelectric film 26 has a power generation function and is provided on the surface of the buffer member 24. More specifically, the piezoelectric film 26 is provided at the contact portion between the buffer member 24 and the face material 20 along the outer periphery of the four sides of the face material 20. The structure and type of the piezoelectric film 26 are not particularly limited. Regarding the structure, any of unimorph, bimorph, laminated type and other known structures may be used. In addition, materials using organic materials and materials using ceramics can also be used.

  FIG. 4 is an exploded perspective view of the power generation device 2. FIG. 4 shows a face material 20, a support member 22, a buffer member 24, and a piezoelectric film 26. The piezoelectric film 26 is formed on the surface of the buffer member 24 by coating.

  The face material 20 is supported in a state having play with respect to the buffer member 24 (that is, the piezoelectric film 26). The length (hereinafter referred to as the gap length) of the clearance (gap) 28 between the face material 20 and the piezoelectric film 26 is preferably about several hundred microns to several millimeters. The power generation efficiency described later, the sealing property required for the window, and the like. Should be determined in consideration of

  The above is the structure of the power generation device 2. Next, the power generation operation by the power generation device 2 will be described.

When wind strikes or vibrates the face material 20, the face material 20 exerts a force on the piezoelectric film 26 at its supporting end. When the piezoelectric film 26 is deformed by this force, the piezoelectric film 26 generates power, and electric power can be taken out from the electrode 30. The power generation device 2 generates power in several different modes.
Fig.5 (a)-(c) is a figure explaining the electric power generation mode of the electric power generating apparatus 2 which concerns on embodiment. In the mode of FIG. 5A, the face material 20 vibrates along the surface of the piezoelectric film 26, that is, in the in-plane direction (XZ plane) while being in contact with the piezoelectric film 26. In the mode of FIG. 5B, the face material 20 is a mode that vibrates in an out-of-plane direction (Y direction) perpendicular to the piezoelectric film 26 while being in contact with the piezoelectric film 26.

  Further, since the clearance 28 is provided between the piezoelectric film 26 and the face material 20, there is also a mode in which the face material 20 collides against the piezoelectric film 26 as shown in FIG.

  FIG. 6 is a diagram illustrating a generated voltage of the power generation device 2 according to the embodiment. B in the center of FIG. 6 shows the generated voltage of the power generation device 2 according to the embodiment. For comparison, the left A of FIG. 6 shows the generated voltage of the power generation device 1r according to the comparison technique of FIG. C on the right of FIG. 6 shows a generated voltage of the power generation device 2 according to the modification. A modification will be described later.

  FIGS. 7A and 7B are plan views showing the comparison technique used for the measurement and the power generation apparatuses 1r and 2r according to the embodiment, respectively. The experiment was performed using 50 cm × 50 cm glass as the face material 20. In the comparative technique, as shown in FIG. 7A, a piezoelectric film 26 was formed on the entire glass surface. In the embodiment, as shown in FIG. 7B, the piezoelectric film 26 is formed on the outer peripheral portion having a width of 1 cm on the four sides of the entire glass surface.

That is, the effective power generation area in the comparative technique is 50 cm × 50 cm = 2500 cm ² , and the effective power generation area in the embodiment is 1 cm × (50−1) cm × 4 = 196 cm ² .

  Returning to FIG. 6B, (i) shows the generated voltage when the gap length is 1 mm, and (ii) shows the generated voltage when the gap length is 0 mm, that is, when the face material 20 and the piezoelectric film 26 are brought into close contact with each other and play is eliminated.

  In the comparative technique A, a generated voltage of 1280 mV (pp: peak to peak) is obtained. On the other hand, in the embodiment B, it can be seen that, in the state (i) where the gap length is 1 mm, 1080 mV (pp) and a generated voltage comparable to that of the comparative technique A can be obtained. In the embodiment, an equivalent power generation voltage can be obtained even though the effective power generation area is only 8% as compared with the comparative technique. Therefore, the power generation efficiency (= power generation voltage / effective power generation area) is increased by about 10 times. You can see that

  In the state (ii) where the gap length of the embodiment B is 0 mm, a generated voltage of 400 mV (pp) is obtained, which is 38% of the state (ii) where the gap length is 1 mm. is there. This is understood to be caused by invalidating the power generation mode using the collision shown in FIG. 5C when the gap length is zero. However, even when the gap length of the embodiment B is 0 mm, the power generation efficiency can be as high as about four times that of the comparative technique A.

  The above is the operation of the power generation device 2. Then, the effect show | played by the electric power generating apparatus 2 is demonstrated.

  In the power generation device 2 according to the embodiment, the piezoelectric film 26 is provided on the surface of the buffer member 24. As a result, the force received by the piezoelectric film 26 when the same external force is applied to the face material 20 is significantly greater than when the piezoelectric film 26 is formed over the entire surface of the face material 20. Therefore, as described above, the power generation efficiency can be increased as compared with the comparative technique.

  This means that the area of the piezoelectric film necessary for generating the same electric power can be reduced, and the cost of the power generation apparatus can be reduced. Alternatively, it is possible to increase the power generation amount when the piezoelectric film having the same area is used.

  Further, in the manufacturing process, it is easier to form the piezoelectric film 26 on the surface of the buffer member 24 than to form the piezoelectric film 26 on the entire face material 20, so that the manufacturing cost is reduced or the manufacturing period is shortened. it can. From the viewpoint of maintainability, it is better to form the piezoelectric film 26 on the surface of the buffer member 24.

  Further, in the comparative technique of FIG. 1, since the piezoelectric film covers the entire face material and it is difficult to form a transparent piezoelectric film, the piezoelectric film affects the appearance. In the embodiment, since the piezoelectric film 26 is concealed by the support member 22 and the buffer member 24, the influence on the appearance can be reduced. This is a very important advantage in the construction industry where design is required.

  Further, the piezoelectric film 26 is provided on the surface of the buffer member 24 and in a contact portion with the face material 20. Thereby, since the force from the face material 20 is directly transmitted to the buffer member 24, the power generation efficiency can be further increased. This advantage will be described again in a modified example.

  Further, the face material 20 is supported with play with respect to the buffer member 24. Thereby, since it can generate electric power efficiently by the electric power generation mode of FIG.5 (c), electric power generation efficiency can be raised more. If the clearance width is increased, the power generation amount in the mode of FIG. 5C increases, but the power generation amount in the modes of FIGS. 5A and 5B may decrease. Therefore, the clearance width may be optimized based on experiments or simulations according to the shape, area, material, etc. of the face member 20 and the buffer member 24, respectively. According to knowledge obtained through experiments, a clearance width of about 0.5 mm to 1 mm is suitable.

  In the embodiment, the piezoelectric film 26 is formed on the surface of the buffer member 24 by coating. When the piezoelectric film 26 is affixed to the buffer member 24, a minute gap is generated between them, and this gap may reduce the transmission of load from the face material 20 to the piezoelectric film 26. On the other hand, since the integrity of the buffer member 24 and the piezoelectric film 26 is increased by applying, the load transmission efficiency can be increased and the power generation efficiency can be increased.

  The present invention has been described based on the embodiments. Those skilled in the art will understand that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. By the way. Hereinafter, such modifications will be described.

  In the embodiment, the case where the piezoelectric film 26 is provided over the entire circumference of the face material 20 has been described, but the present invention is not limited to this. The piezoelectric film 26 can be provided on any three sides, any two sides, or any one side.

8A to 8D are cross-sectional views showing a power generation device 2 according to a modification.
In the modification of FIG. 8A, the piezoelectric film 26 is formed on the surface of the buffer member 24 on the surface opposite to the face material 20. C of FIG. 6 shows the generated voltage according to the modification of FIG. In this modification, the power generation voltage (power generation efficiency) is reduced as compared with the case where the piezoelectric film 26 is provided on the contact surface of the buffer member 24 with respect to the face material 20, but still higher power generation efficiency can be realized as compared with the comparative technique. I understand.

  In the modification of FIG. 8B, piezoelectric films 26 a and 26 b are formed on two surfaces parallel to the face material 20 in the surface of the buffer member 24. In the modification of FIG. 8C, the piezoelectric film 26 is formed on the side surface of the buffer member 24. In the modification of FIG. 8D, the piezoelectric film 26 is formed on both the bottom surface and the side surface of the piezoelectric film 26. According to those skilled in the art, in addition to those shown in FIGS. 8A to 8D, the piezoelectric film 26 is formed on the entire periphery, the piezoelectric film 26 is formed on both side surfaces, and the piezoelectric film is formed on any three surfaces. And the like formed within the scope of the present invention.

  FIGS. 9A to 9C are cross-sectional views showing a power generation device 2 according to another modification. The buffer member 24 of FIG. 9A is provided with regular or random protrusions on the surface, and a piezoelectric film 26 is formed thereon. Thereby, the surface area of the piezoelectric film 26 can be increased, and the power generation efficiency can be increased.

  The buffer member 24 in FIG. 9B is formed hollow. The buffer member 24 of FIG. 9C has a U-shaped cross section, and the piezoelectric film 26 is formed on one or both of the left and right sides that can be deformed. In these modifications, the buffer member 24 can be easily deformed, the force applied to the piezoelectric film 26 can be increased, and the power generation efficiency can be increased.

  In the embodiment, the case where the piezoelectric film 26 is in contact with the plane of the face material 20 has been described, but the present invention is not limited thereto. 10A and 10B are cross-sectional views showing a power generation device 2 according to another modification. In the modification of FIG. 10A, the piezoelectric film 26 is formed on the surface of the buffer member 24 and in contact with the side surface S <b> 1 of the face material 20. In the modification of FIG. 10B, the piezoelectric film 26 is formed at a location in contact with both the flat surface S2 and the side surface S1 of the face material 20. Also by these modified examples, high power generation efficiency similar to that of the embodiment can be obtained.

Finally, a modified example regarding the application of the power generation device 2 will be described. In the embodiment, the case where the power generation device 2 is attached to the window has been described, but the present invention is not limited thereto.
FIGS. 11A to 11D are diagrams showing a power generation device 2 according to a modification. In the modification of Fig.11 (a), the electric power generating apparatus 2 is utilized for the panel of the roof of a building. In the modification of FIG.11 (b), the electric power generating apparatus 2 is utilized for the outer wall panel of a building. In the modification of FIG. 11C, the power generation device 2 is used for a floor on which a human walks. In the modification of FIG. 11D, the power generator 2 is used for a panel of an automobile. Examples of the automobile panel include a bonnet panel, a fender panel, and a door panel. In addition to automobiles, the present invention can also be applied to moving means composed of a combination of panels such as airplanes, ships, railways, wind turbine propeller blades, desks and chairs, and toilet seats on trays.

  Moreover, regarding the use of the power generation device 2, it may be used for vibration detection in addition to or instead of power generation.

  The above-described embodiments and arbitrary modifications can be combined, and combinations thereof are also included in the scope of the present invention.

  Although the present invention has been described using specific terms based on the embodiments, the embodiments only illustrate the principles and applications of the present invention, and the embodiments are defined in the claims. Many variations and modifications of the arrangement are permitted without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 2 ... Electric power generation apparatus, 20 ... Face material, 22 ... Support member, 24 ... Buffer member, 26 ... Piezoelectric film, 28 ... Buffer member, 30 ... Electrode, 50 ... Wall surface, 52 ... Opening part.

Claims (4)

Face material,
A support member for supporting the face material;
A buffer member provided between the face material and the support member;
A piezoelectric film having a power generation function provided on the surface of the buffer member;
A power generation device comprising:   The power generation device according to claim 1, wherein the piezoelectric film is provided on a surface of the buffer member and in a contact portion with the face material.   The power generator according to claim 1, wherein the face material is supported in a state having play with respect to the buffer member.   The power generation apparatus according to claim 1, wherein the piezoelectric film is formed on the surface of the buffer member by coating.

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