JP2006158111A - Piezoelectric power generation element and wireless switch utilizing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a piezoelectric power generation element in which containability and power generation efficiency are enhanced by making a stress being generated in the piezoelectric element uniform at the time of power generation. <P>SOLUTION: A power generating section A has a planar piezoelectric element 1 and a supporting plate 2 bonded with the piezoelectric element 1 and the supporting plate 2 has a displaceable free end 2a and a supporting end 2b to be secured. The power generating section A is arranged such that the width dimension of the piezoelectric element 1 and the supporting plate 2 in the direction intersecting the direction connecting the free end 2a and the supporting end 2b becomes larger on the supporting end 2b side than on the free end 2a side. When the vicinity of the free end 2a is pressed by an external force and the supporting plate 2 is bent uniformly from the free end 2a to the supporting end 2b, a stress being generated in the piezoelectric element uniform 1 becomes uniform and power is generated efficiently. A plurality of power generating sections A of the piezoelectric power generation element are arranged efficiently for a predetermined containing area such that the sides of the supporting plates 2 are arranged in close proximity and power generation efficiency is enhanced when viewed from containability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a piezoelectric power generating element and a small and thin wireless switch using the piezoelectric power generating element.

As a conventional power generation element using a piezoelectric element, a power generation element having a beam structure in which a piezoelectric element and a support plate are laminated, one end is a free end that can be displaced, and the other end is a fixed support end is known. This power generation element generates electric power when an external force acts near the free end and vibrates freely, the piezoelectric element and the support plate bend, and stress is generated in the piezoelectric element. Here, if the power generation element with a beam structure is rectangular, the support end side bends greatly, so the piezoelectric element generates a critical stress near the support end, and the stress is reduced on the free end side, resulting in a useless piezoelectric element part. To do. In order to make the stress generated in the piezoelectric element uniform and to increase the power generation efficiency with respect to the volume of the piezoelectric element, as disclosed in Patent Document 1, the support end with respect to the free end side of the beam structure power generation element A technique for increasing the width dimension on the side is known.
Japanese Patent Laid-Open No. 9-205781

  However, in applications where the power generation element is incorporated into a small device, the power generation element configured such that the width dimension on the support end side is larger than the free end side as described above is compared with a rectangular power generation element. The ratio of the area of the piezoelectric element to the area occupied by the power generation element becomes small, and the power generation efficiency from the viewpoint of storage is not good.

  The present invention has been made in view of the above-mentioned problems, and provides a piezoelectric power generating element that improves the storage performance and power generation efficiency by making the stress generated in the piezoelectric element uniform during power generation. Objective.

  In order to achieve the above object, a first aspect of the present invention provides a plate-like piezoelectric element, an elastically deformable support plate having the same shape as the outer shape of the piezoelectric element, and the piezoelectric element. Each of the support plates has a displaceable free end and a fixed support end, and the free end and the support end, The width dimension of the piezoelectric element and the support plate in the direction perpendicular to the direction connecting the two is configured such that the support end side is larger than the free end side, and the power generation unit is on the free end side of the support plate In the piezoelectric type power generating element that generates electric power when an external force acts on the support plate and the piezoelectric element, a plurality of the power generating parts are provided, and a space between the free end part and the support end part of one support plate is provided. Side of the other adjacent departure It is obtained by the side of the support plate parts and construction which are arranged close.

  According to a second aspect of the present invention, in the first aspect of the invention, the free end portions of the plurality of support plates are arranged so as to face the center of the power generating element, and all the free end portions are pressed and moved near the center. The pressing means is provided.

  According to a third aspect of the present invention, in the first aspect of the invention, the support plate is bent in the vicinity of the support end, and the power generation unit is externally connected to the support end while the free end is constrained. It is configured to generate electricity when force is applied.

  According to a fourth aspect of the present invention, there is provided a rectangular plate-shaped piezoelectric element, an elastically deformable support plate to which the piezoelectric element is fixed, substantially the same shape as the outer shape of the piezoelectric element, and electric power generated by the piezoelectric element. A power generation unit including an electrode for drawing out, the support plate having a displaceable free end and a support end on the fixed side, and the power generation unit is located on the free end side of the support plate In the piezoelectric power generating element that generates electric power when an external force acts and the support plate and the piezoelectric element bend, the support plate includes a plurality of holes, and the plurality of holes includes a free end portion and a support end portion of the support plate. With respect to the width dimension in the direction perpendicular to the direction connecting the two, the opening ratio increases from the support end toward the free end.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, the size of the plurality of holes increases from the support end of the support plate toward the free end, or the number of holes increases. It is set as the structure provided in this way.

  According to a sixth aspect of the present invention, a plate-like piezoelectric element, an elastically deformable support plate having the same shape as the outer shape of the piezoelectric element, and the electric power generated by the piezoelectric element are drawn out. A power generation section including an electrode for the support plate, the support plate having a displaceable free end portion and a fixed support end portion, and the power generation portion is external to the free end portion side of the support plate. In a piezoelectric power generating element that generates electric power by bending a support plate and a piezoelectric element by applying force, the piezoelectric element and the support plate are formed in a spiral shape with a support end or a free end as a center. .

  According to a seventh aspect of the present invention, a wireless switch for a wireless communication device that transmits a signal to a controlled device operates using power generated by the piezoelectric power generation element according to any one of the first to sixth aspects as a power source. The configuration is as follows.

  According to the first aspect of the present invention, since the support plate of the power generation unit is shaped so that the width dimension on the support end side is larger than the free end side, the stress generated in the piezoelectric element is uniform. As a result, the power generation efficiency of the power generation section is improved. In addition, since the plurality of power generation units are arranged so that the sides of each support plate are close to each other, the power generation units can be efficiently arranged within a certain storage area, and stress is uniformly generated. Therefore, it is possible to secure a large area of the piezoelectric element to be performed, and therefore, the power generation efficiency from the viewpoint of storage property is improved.

  According to the second aspect of the present invention, the plurality of power generation units are arranged with their respective free ends directed toward the center of the piezoelectric power generation element, and each of the plurality of power generation units is freed by pressing means near the center of the power generation element. Since the end portion is pushed and moved, the power generation efficiency from the viewpoint of storage is improved, and the entire power generation element can be easily driven by one pressing means.

  According to the invention of claim 3, each power generation unit is bent in the vicinity of the support end, the free end is constrained, and an external force acts on the support end side of the plurality of power generation units. To generate electricity. As described above, since the piezoelectric power generating element can be driven by pressing the support end side, it is possible to easily drive a plurality of power generating units regardless of the arrangement of the power generating units, and to store them. Power generation efficiency seen from the viewpoint of improvement.

  According to the invention of claim 4, since the plurality of holes are provided in the support plate so that the opening ratio increases from the support end of the rectangular support plate toward the free end, the free end side When an external force acts on the support plate and the piezoelectric element, the support plate and the piezoelectric element bend more uniformly from the support end side to the free end side, the stress generated in the piezoelectric element becomes uniform, and the power generation efficiency is improved. Further, the power generation unit has a rectangular shape, and the power generation efficiency is good from the viewpoint of storage.

  According to the invention of claim 5, since the hole is provided in the support plate so that the size of the hole is large or the number of the holes is increased from the support end portion toward the free end portion, the above effect is obtained. It can be obtained more easily.

  According to the invention of claim 6, since the power generation unit has a spiral shape centered on the support end or the free end, an external force acts on the free end and the support end side like a coil spring. To the free end side more uniformly, the stress generated in the piezoelectric element becomes uniform, and the power generation efficiency is improved. In addition, since the area of the piezoelectric element can be secured wider than the area occupied by the piezoelectric power generation element, the power generation efficiency from the viewpoint of storage is improved.

  According to the seventh aspect of the present invention, since the piezoelectric power generation device with improved storability and power generation efficiency is used as the power source of the wireless switch, the wireless switch can be made small and thin, and the battery can be replaced. Becomes unnecessary, and the usability of the wireless switch is improved.

  Hereinafter, first to fifth embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a schematic configuration of a piezoelectric power generation element according to the first embodiment. This piezoelectric power generation element is composed of a plurality of power generation units A. FIG. 2A shows a schematic configuration when one power generation unit A is viewed from the side, and FIG. 1 shows a schematic configuration when viewed from a surface to which a piezoelectric element 1 is fixed. The power generation unit A is provided on the piezoelectric element 1, the support plate 2 to which the piezoelectric element 1 is fixed, the electrode 1a provided on the surface where the support plate 2 of the piezoelectric element 1 is not fixed, and the opposite surface. The piezoelectric element 1 and the support plate 2 have substantially the same shape.

  The power generation unit A has a support plate 2 having a displaceable free end 2a and a fixed support end 2b, and is fixed to the fixed part B at the support end 2b. And the electric power generation part A is pressed near the free end part 2a, and the piezoelectric element 1 and the support plate 2 between the free end part 2a and the support end part 2b are bent in the black arrow direction of FIG. Electric power is generated when stress is generated inside the piezoelectric element 1. As shown in FIG. 2B, the power generation unit A has a width of the piezoelectric element 1 and the support plate 2 in the direction (X direction) orthogonal to the direction (Y direction) connecting the free end 2a and the support end 2b. The dimension is configured such that the support end 2b side is larger than the free end 2a side. When the free end 2a is pressed and the piezoelectric element 1 and the support plate 2 are bent, the piezoelectric element 1 The internal stress is uniform, and the power generation efficiency with respect to the volume of the piezoelectric element 1 is increased.

  As shown in FIG. 1, the power generation unit A has a side between a free end 2 a and a support end 2 b of one support plate 2 and a side of the support plate 2 of another power generation unit A. A plurality of elements are arranged adjacent to each other and fixed to the fixing portion B to form one piezoelectric power generating element (corresponding to claims 1 to 3). In FIG. 1, a plurality of power generation units A are arranged so as to be opposed to each other, and each power generation unit A can freely move independently of the other power generation units A. And this piezoelectric type electric power generating element drives each electric power generation part A by the vicinity of each free end part 2a in a plurality of electric power generation parts A by external force, and generates electric power, electrode 1a, electrode The generated electric power is drawn from 1b. At this time, the fixing part B may be provided so as to be one fixing part B common to the plurality of power generation parts A as shown in the figure, and provided so that each power generation part A has a separate fixing part B. Also good.

  In the first embodiment, as described above, a plurality of power generation units A whose power generation efficiency is improved by making the stress of the piezoelectric element uniform are arranged adjacent to each other. By arranging in this way, it is possible to efficiently arrange the power generation unit A within a certain storage area, compared with the case where the power generation units A are simply arranged adjacent to each other in a row, and stress is uniformly generated. Therefore, it is possible to secure a large area of the piezoelectric element to be improved, and the power generation efficiency is improved from the viewpoint of storage.

  Next, FIG. 3 shows an example of a schematic configuration of the piezoelectric power generating element in the second embodiment. In the following description of the embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals, description thereof will be omitted, and only differences will be described. The piezoelectric power generating element includes a plurality of power generating units A, each side of the power generating unit A being adjacent to a side of another power generating unit A, and the free end 2a is a power generating element. It is arranged so as to face the center. And the press means 3 is provided in the center vicinity, and the free end part 2a of all the electric power generation parts A is pressed by the press means 3, and the electric power generation part A is driven (corresponding to claim 2). That is, in order to drive this piezoelectric power generating element, it is only necessary to press one pressing means 3 provided near the center, and the piezoelectric power generating element can be easily driven.

  Moreover, an example of schematic structure of the piezoelectric power generation element in 3rd Embodiment is shown in FIG. This piezoelectric power generating element has a shape in which the support plate 2 of each power generation section A is bent in the vicinity of the support end 2b (corresponding to claim 3). FIG. 4 shows a piezoelectric power generation element having a shape in which the support plate 2 is bent in the arrangement of the power generation unit A as in the second embodiment, and FIG. 5 shows a piezoelectric power generation element as shown in FIG. A cross-sectional shape is shown. In the present embodiment, the free end 2a is in contact with the outer wall C as shown in FIG. 5, and the free end 2a is constrained so as not to move in the direction of the outer wall C. A pressing plate D is provided on the side opposite to the outer wall C of the piezoelectric power generating element, and the pressing plate D is pressed by an external force. Then, as indicated by the white arrows in the figure, the piezoelectric plate 1 and the support plate 2 of each power generation unit A are bent when the pressing plate D is pressed near the support end 2b of the piezoelectric power generation device. The piezoelectric power generation element is driven. Since the piezoelectric power generation element can be driven in this way, a plurality of power generation units A can be easily driven regardless of the arrangement of the power generation units A.

  FIGS. 6A to 6C show an example of a schematic configuration of the piezoelectric power generation element in the fourth embodiment. In the present embodiment, the piezoelectric element 1 and the support plate 2 of the power generation unit A of the piezoelectric power generation element have a rectangular shape. The support plate 2 of the power generation unit A is provided with a plurality of holes, and the piezoelectric element 1 is not provided with a hole. This hole increases from the support end 2b side to the free end 2a side with respect to the width dimension in the direction orthogonal to the direction connecting the free end 2a and the support end 2b of the support plate 2 (X direction). It is provided so as to increase the aperture ratio (corresponding to claims 4 and 5). That is, at the position indicated by the dotted line E and the position indicated by the dotted line F in FIG. 6C, the aperture ratio at the position indicated by the dotted line E close to the free end 2a is the aperture ratio at the position indicated by the dotted line F. A hole 21 and a hole 22 are provided so as to be larger.

  Since the plurality of holes are provided as described above and the free end portion 2a side is more easily bent, the piezoelectric power generating element is driven by pressing the free end portion 2a of the support plate 2, and the support plate 2 is driven. And the piezoelectric element 1 are uniformly bent from the support end 2b side to the free end 2a side, and a uniform stress is generated in the piezoelectric element 1. As described above, since the stress generated in the piezoelectric element 1 becomes uniform, the power generation efficiency is improved, and the power generation section A has a rectangular shape, and the power generation efficiency from the viewpoint of storage is good. Here, the holes provided in the support plate 2 are provided so that the size of the holes gradually increases in the direction from the support end 2b toward the free end 2a (the Y direction in FIG. 6C). Alternatively, the number of holes may be increased (corresponding to claim 5).

  FIG. 7 shows an example of a schematic configuration of the piezoelectric power generating element in the fifth embodiment. In the present embodiment, the power generation section A of the piezoelectric power generation element has a spiral shape from the support end section 2b fixed to the fixed section B to the free end section 2a. When the free end 2a is pressed and driven, the support plate 2 and the piezoelectric element 1 of the power generation unit A are uniformly bent from the support end 2b side to the free end 2a side like a coil spring, and the piezoelectric element 1 is evenly stressed. As described above, since the stress generated in the piezoelectric element 1 becomes uniform, the power generation efficiency is improved, and the area of the piezoelectric element 1 relative to the area occupied by the piezoelectric power generation element can be efficiently secured. Can be improved. Here, the power generation unit A may have a spiral shape from the free end 2a to the support end 2b, and at this time, by pressing the free end 2a, power generation can be efficiently performed in the same manner.

  Next, with reference to FIGS. 8 to 10, an embodiment of a wireless switch for a wireless communication apparatus provided with the piezoelectric power generating element according to any of the first to fifth embodiments will be described. This wireless switch operates using power generated by the piezoelectric power generation element as a power source, and transmits a signal to the controlled device. FIGS. 8A and 8B show a piezoelectric power generation element having three power generation units A having the same configuration as that of the first embodiment, and a wireless switch including the piezoelectric power generation element. In this wireless switch, the piezoelectric power generating element fixing portion B and the wireless communication device 50 are fixed to the casing 51, and the electrodes 1 a and 1 b of the piezoelectric power generating element and the wireless communication device 50 are connected by a wire 54. The A switch handle 52 is provided on the casing 51 via a hinge 53 so as to be rotatable in the direction of the arrow in the figure. The piezoelectric power generating element pressing means 3 is fixed to the switch handle 52. When the switch handle 52 is pressed in the direction of the arrow, the pressing means 3 presses the support plate 2 of the piezoelectric power generating element.

  Here, the pressing means 3 presses three pressing portions P (regions surrounded by a two-dot chain line) in the vicinity of the free end portion 2a of the power generating portion A of the piezoelectric power generating element in FIG. When the switch handle 52 is pressed, the support plates 2 and the piezoelectric elements 1 of the three power generation units A are simultaneously bent in the black arrow direction. The electric power generated by the piezoelectric power generation element by bending the piezoelectric element 1 in this way is supplied to the wireless communication device 50 from the electrodes 1 a and 1 b through the wiring 54. When the wireless communication device 50 is supplied with power, the wireless communication device 50 transmits to the controlled device an inversion signal that turns on / off the operation of the controlled device, for example. As described above, the power source of the wireless switch is a piezoelectric power generation element with improved storability and power generation efficiency, so that the wireless switch can be reduced in size and thickness, and battery replacement is not necessary. Therefore, the usability of the wireless switch can be improved.

  FIGS. 9A and 9B show a piezoelectric power generation element having the same configuration as that of the second embodiment and a wireless switch including the piezoelectric power generation element. In this piezoelectric power generation element, the free end 2a of each power generation unit A faces the center of the piezoelectric power generation element, and the pressing portion P is at one place near the center. The pressing means 3 is fixed to the switch handle 52 so as to press the pressing portion P (a region surrounded by a two-dot chain line). Like the wireless switch, the pressing means 3 is all pressed by pressing in the direction of the arrow. The power generation unit A is configured to be driven. Other configurations are the same as the configuration of the wireless switch as described above.

  Even when the piezoelectric power generating element having the same configuration as that of the fourth or fifth embodiment is provided as the power source of the wireless switch, the piezoelectric power generating element is pressed by the switch handle 52 in the configuration of the wireless switch as described above. What is necessary is just to change the press means 3. FIG. That is, by configuring the wireless switch by changing the position of the pressing means 3 so that the position pressed by the pressing means 3 is in the vicinity of the free end 2a in the support plate 2 of the power generation section A of the piezoelectric power generation element, The piezoelectric power generation element can be driven.

  FIGS. 10A and 10B show a piezoelectric power generation element having a configuration similar to that of the third embodiment and a wireless switch including the piezoelectric power generation element. The fixed portion B of the piezoelectric power generating element is not fixed to the casing 51, the support plate 2 of the power generating section A is bent near the fixed end 2b, and the free end 2a is connected to the casing 51 of the wireless switch. The piezoelectric power generation element and the casing 51 are configured so as to come into contact with each other. A pressing plate D is provided between the piezoelectric power generating element and the pressing means 3 provided on the switch handle 52. When the switch handle 52 is pressed in the direction of the arrow, the piezoelectric power generating element is interposed via the pressing plate D. The pressing portion P (region surrounded by a two-dot chain line) on the support end 2b side is pressed, and the support end 2b side of the piezoelectric power generating element is displaced in the direction of the arrow. The free end portion 2a is in contact with the casing 51, and when the movement in this direction is restricted, the support plate 2 of the piezoelectric power generating element and the piezoelectric element 1 are bent, and the piezoelectric power generating element generates power. Other configurations are the same as the configuration of the wireless switch as described above.

  In addition, this invention is not limited to the structure of said each embodiment, A various deformation | transformation is suitably possible in the range which does not change the range of invention. For example, in the fourth embodiment, the holes provided in the support plate 2 may be elliptical, rectangular, or the like, and the same effect can be obtained even if these variously shaped holes are mixed.

1 is a front view of a piezoelectric power generation element according to a first embodiment of the present invention. (A) is a side view of one electric power generation part A in the said embodiment, (b) is the front view. The front view of the piezoelectric power generation element which concerns on the 2nd Embodiment of this invention. The perspective view of the piezoelectric power generation element which concerns on the 3rd Embodiment of this invention. Side sectional drawing before and behind operation | movement of a piezoelectric power generation element same as the above. (A) is a front view of a piezoelectric power generating element according to a fourth embodiment of the present invention, (b) is a side view thereof, and (c) is a rear view thereof. The top view of the piezoelectric power generation element which concerns on the 5th Embodiment of this invention. (A) is a plan view of a piezoelectric power generation element having the same configuration as that of the first embodiment, (b) shows a wireless switch including the piezoelectric power generation element of the above, and a GG line of (a) Sectional drawing. (A) is a plan view of a piezoelectric power generating element having the same configuration as that of the second embodiment, (b) shows a wireless switch including the piezoelectric power generating element of the above, and HH line of (a) Sectional drawing. (A) is a plan view of a piezoelectric power generation element having the same configuration as that of the third embodiment, (b) shows a wireless switch including the piezoelectric power generation element of the above, and a line II of (a) Sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric element 1a Electrode 1b Electrode 2 Support plate 2a Free end part 2b Support end part 3 Pressing means 50 Wireless communication apparatus A Power generation part B Fixing part

Claims (7)

A power generation unit comprising a plate-shaped piezoelectric element, an elastically deformable support plate to which the piezoelectric element is fixed, and substantially the same shape as the outer shape of the piezoelectric element, and an electrode for extracting the power generated by the piezoelectric element Each of the support plates has a displaceable free end and a fixed support end, and a piezoelectric element and a support plate in a direction perpendicular to a direction connecting the free end and the support end The power generation unit is configured such that an external force acts on the free end portion side of the support plate so that the support plate and the piezoelectric element are connected to each other. In a piezoelectric power generating element that generates power by bending,
A plurality of the power generation units are provided, and a side between a free end and a support end of one support plate is disposed close to a side of a support plate of another adjacent power generation unit. A piezoelectric power generating element characterized. Each free end of the plurality of support plates is arranged to face the center of the piezoelectric power generation element,
2. The piezoelectric power generating element according to claim 1, wherein pressing means for pressing and moving all free ends is provided near the center. The support plate is bent near the support end,
The piezoelectric power generating element according to claim 1, wherein the power generation unit generates power by applying an external force to the support end side in a state where the free end is constrained. A rectangular plate-shaped piezoelectric element, an elastically deformable support plate to which the piezoelectric element is fixed, substantially the same shape as the outer shape of the piezoelectric element, and an electrode for extracting electric power generated by the piezoelectric element are provided. A power generation unit, the support plate having a displaceable free end and a fixed support end; and the power generation unit is supported by an external force acting on the support plate free end. In the piezoelectric power generating element that generates electricity by bending the plate and the piezoelectric element,
The support plate comprises a plurality of holes;
The plurality of holes are provided such that the aperture ratio increases from the support end toward the free end with respect to the width dimension in a direction perpendicular to the direction connecting the free end and the support end of the support plate. A piezoelectric power generating element characterized by being provided.   5. The plurality of holes are provided such that the size of the holes increases or the number of holes increases from the support end of the support plate toward the free end. The piezoelectric power generation element as described. Electric power generation comprising a plate-like piezoelectric element, an elastically deformable support plate to which the piezoelectric element is fixed, substantially the same shape as the outer shape of the piezoelectric element, and an electrode for extracting electric power generated by the piezoelectric element The support plate has a displaceable free end portion and a fixed support end portion, and the power generation portion is supported by an external force acting on the support plate free end portion side. And in the piezoelectric type power generating element that generates power by bending the piezoelectric element,
The piezoelectric element and the support plate are formed in a spiral shape with a support end or a free end as a center. A wireless switch for a wireless communication apparatus that operates using the electric power generated by the piezoelectric power generation element according to any one of claims 1 to 6 as a power source and transmits a signal to a controlled device.

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