JP2007202293A - Generating set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a generating set exhibiting high power generation efficiency and good operability. <P>SOLUTION: A piezoelectric device in which a plurality of rectangular or sectoral piezoelectric elements of substantially identical dimensions are arranged such that the longitudinal direction of the rectangular piezoelectric elements or the radial direction of the sectoral piezoelectric elements becomes the radial direction of one assumed circle includes a supporting section for supporting the end portions of the piezoelectric elements close to the center of the circle integrally, and other supporting section for narrowing the interval of the other ends of circumferential portion of adjoining piezoelectric elements and securing the other ends of the piezoelectric elements to flex freely to the same side of the circle wherein power is generated by reciprocating one supporting section in the direction perpendicular to the circle and repeating flexure and inversion of the piezoelectric elements. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power generation device configured using a piezoelectric element.

  2. Description of the Related Art In recent years, application development of power generation apparatuses using a piezoelectric element such as a bimorph type that has flexibility and generates electric power by bending under external force has been actively performed. For example, the piezoelectric generator disclosed in Patent Document 1 is a piezoelectric generator that is formed in a shape bent in a predetermined direction in advance or combined with a buckled and deformed leaf spring and a piezoelectric element. When a constant external force is applied in the direction to return the bending of the leaf spring, utilizing the fact that the bending direction is instantaneously reversed, the vibration of the spring spring generated at this time is transmitted to the piezoelectric element to generate power, and In the configuration of the piezoelectric power generation element, a piezoelectric power generator that is a piezoelectric bimorph element or a piezoelectric unimorph in which a piezoelectric material is directly bonded to a spring plate spring whose bending direction is reversed is disclosed.

  However, in order to obtain an instantaneous reversal displacement, a spring leaf spring that is bent or molded in advance or buckled and deformed so that a compression force is inherent in the leaf spring is used. Therefore, since the support member is not bent, the electromotive force cannot be taken out from those that do not reverse with a small external force, and in order to obtain a large electromotive force, a large external force is applied with a large bending and a relatively large curvature. I need. It is difficult to create a shape in which bending starts from a place where an external force is applied and the whole is reversed at once. Since it has an elliptical sphere with a large curvature, it is a shape that is fragile as it is, and it has a structure that is difficult to increase in size and stack.

In addition, in this type of power generation device, it is difficult to increase the size and stacking, so it is not possible to take out a large amount of power, so natural energy such as tidal currents, water currents, and winds cannot be efficiently converted into electrical energy. . In addition, since it is pushed several times even in a small device, if a compact power generator using this pressing force can be realized, it will be extremely useful for assisting the power battery. Not only a mobile phone but also a portable electronic device such as a notebook computer can be used effectively to assist a power supply battery if power can be generated by tapping the keyboard. Furthermore, even in a portable device that does not have a keyboard, if the human power released in daily life can be effectively extracted as a voltage, it can be effectively used as a power source for the portable device.
Japanese Patent Laid-Open No. 2003-116285

  The present invention has been made in view of such circumstances, and an object thereof is to provide a power generation device having high power generation efficiency. The present invention also uses natural energy such as pressing force by a person, for example, a key operation by a hand, a button pressing operation, an operation of stepping on a heel of a shoe by a foot, a button pressing operation, or a tidal current. An object is to provide a highly efficient power generator.

  A piezoelectric element that is attached to a plurality of rectangular or fan-shaped shims having substantially the same dimensions is assumed to have a radius of one circle in which the longitudinal direction of the rectangular piezoelectric element or the radial direction of the sector-shaped piezoelectric element is assumed. The piezoelectric device is arranged so as to be in a direction, and a gap between a support portion that integrally supports an end portion of the piezoelectric element close to a circular center portion and a circumferential end portion of the adjacent piezoelectric element is narrowed. The other end of the piezoelectric element so as to be bent so as to be bent on the same side of the plane including the circle, and the one support portion on the plane including the circle. By generating reciprocal motion relative to the other support portion in a vertical direction, the piezoelectric element is repeatedly bent and inverted to the opposite side of the plane including the circle to generate power. An apparatus (Claim 1), in place of the other support, or The power generation device according to claim 1 (Claim 2), the power generation device according to Claim 1 or 2, wherein a connecting portion that generates tension between the piezoelectric elements is mounted together with the support portion. A plurality of the one support portions are connected in a direction perpendicular to a plane including the circle, and a plurality of the support portions are stacked, and a part or all of the other end close to the circumferential portion is supported by another common support member. And the other support member is a partition wall in the cylinder or connected to the cylinder, wherein the generated power is generated by the reciprocating motion of the supported support portion. The power generator (Claim 4) according to any one of claims 1 to 3, wherein the power generator is driven by a pressure change caused by movement of a fluid guided into the cylinder. If an elastic body for tension adjustment, for example, a coil spring or the like, which is an elastic body, is further attached to the connecting portion of the power generator according to the second aspect, the electromotive force can be adjusted and the stress of the piezoelectric element can be adjusted.

  In the power generation device according to claim 1, when the one supporting portion is reciprocated in a direction perpendicular to the circle and the piezoelectric element is repeatedly inverted, the piezoelectric element is included in the assumed plane of the circle. Due to the sudden displacement from the flat state, large electric energy can be efficiently generated from the piezoelectric element. In the power generation device according to the second aspect, adjacent and facing piezoelectric elements are bent by the tension of the connecting portion, so that bending and reversal can be controlled. As a result, the electromotive force from each piezoelectric element can be made more uniform, and the amount of power generation can be controlled. In addition, when the bending by the support only at the other end support portion is constant and adjustment is difficult, for example, the bending at the other end support portion is made small and the bending is adjusted at the connecting portion, and further the elastic body The tension due to the connection can be adjusted. Excessive stress is not applied to the piezoelectric element at the time of reversal, and appropriate tension can be applied by the connecting portion and the elastic body to adjust the durability, bending and reversal control of the device.

  According to a third aspect of the present invention, a plurality of the power generation devices are stacked and driven in conjunction with each other, so that the power generation amount per unit time can be increased or the power generation amount can be made uniform. In invention of Claim 4, an efficient electric power generating apparatus is realizable using natural energy, such as a tidal current. Furthermore, when the piezoelectric element and the shim are arranged so as to overlap in the direction in which the pressing force is applied, there is an effect that a compact configuration can be obtained. In the present invention, since the shim abuts against the elastic body, when the shim is reversed by applying a pressing force to the shim, the elastic body applies a re-inversion force to the shim. Therefore, when the force is reversed again by this force, it is possible to continuously generate power by repeatedly applying an external force.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a plan view of a schematic structure of the power generation apparatus 10 and a front view showing an operation state. As shown in FIG. 1 (a), the power generation device 10 includes a plurality of piezoelectric elements 11 (11a, 11a, 13) including a shim 13 (represented collectively as 13a, 13b, 13c, etc.) and a piezoelectric plate attached thereto. 11b, 11c, etc.) are arranged radially so that the longitudinal direction is the radial direction of one assumed circle, and the end close to the center of the circle is integrated with one support 14 The other end near the circumference is supported by another support member 16. In FIG. 1, the other end of the pair of opposing piezoelectric elements 11 is supported by another support member 16, but the other support is, for example, a cylindrical support (the support 17 of FIG. 1B). May be expressed as a “front sectional view”), and a circular V-shaped groove may be provided on the inside to support all the piezoelectric elements 11. At this time, the other end on the circumferential side of the adjacent piezoelectric element is narrowed, and the other end is held by the support member so as to be bent to the same side of the plane including the circle.

  In this example, a wire 15 is further used as a connecting portion for generating tension between the piezoelectric elements. The wire 15 connects adjacent piezoelectric elements so as to narrow the other end. The wire 15 passes through the hole at the other end of the adjacent piezoelectric element, and makes a circle while forming these circles in order. Finally, the tension is adjusted to complete the circle. May be. The connecting portion is not limited to a string-like member such as a wire or an elongated cylindrical rod, but may be a planar shape, and is a member that can be folded or contracted to connect adjacent piezoelectric elements including other end portions. May be. An aspect in which a cloth part of an umbrella is formed may be used. As shown in FIG. 2, the wire 15 may be provided with a coil spring 18 as an elastic body to adjust the tension. The piezoelectric element 11 is configured by being attached to a shim. The part (piezoelectric part) which exhibits the piezoelectric effect of a piezoelectric element has a piezoelectric plate or a piezoelectric plate and a metallic piezoelectric element shim plate (not shown) adhered thereto and an adhesive layer (not shown) between them. Are also preferably used.

    In FIG. 1, a piezoelectric plate 12 is made of, for example, a lead zirconate titanate piezoelectric material, is polarized in the thickness direction, and has a rectangular shape with the radial direction in FIG. 1 as the longitudinal direction. The piezoelectric material is not limited to this. Here, a so-called unimorph type structure is used as the piezoelectric element 11, but the piezoelectric element 11 is not limited to this, and has various flexibility such as a monomorph element, a bimorph element, and a laminated bimorph element. A piezoelectric element can be used. The piezoelectric element shim plate and shim are made of an ordinary metal or plastic material having elasticity, but metal is preferable from the viewpoint of durability.

  In the case where the shim 13 is made of metal, the piezoelectric plate and the shim 13 can be electrically connected, so that the shim 13 can be used as an electrode. In the piezoelectric element 11 having the piezoelectric plate and the metallic piezoelectric element shim plate adhered to the piezoelectric plate instead of the piezoelectric plate, when the shim 13 and the piezoelectric plate are not electrically connected, the piezoelectric portion and the support member In order to insulate 16, the piezoelectric part is preferably sandwiched between flexible plastic plates or coated. Such a configuration in which the piezoelectric portion is sandwiched between plastic plates is preferable from the viewpoint of protecting the piezoelectric portion and from the viewpoint of adjusting the bending strength of the entire piezoelectric element 11.

  As shown in FIG. 1B, the piezoelectric element 11 has a piezoelectric element 11 adjacent to each other by the support member 16 and the wire member 15 so as to be convex in the direction in which the external force F is applied in a state where no external force is applied. The other end is bent and supported so as to bend to the same side of the plane including the circle by narrowing the interval between the other ends close to the circumference. Further, the shim 13 to which the piezoelectric element 11 is attached may be supported by a supporting member such as a ring so that the other end of the piezoelectric element 11 is partially bent or bent.

  In order to facilitate the support of the shim 13 by the support member 16 before and after the inversion of the shim 13, a groove is formed in the support end portion of the support member 16. The groove 17 of the support member 16 has a V-shaped valley shape in the front view, and a side surface having a shape represented by a parallel line having a width due to reverse deformation.

  In the power generation apparatus 10 configured as described above, when the external force F acts on the support portion 14, the piezoelectric element 11 bends. When the external force F is large enough to reverse the piezoelectric element 11, the state shown in FIG. 1 (b) is shifted to the state shown in FIG. 1 (c). As shown in FIG. 1 (c), the piezoelectric element 11 is inverted and deformed after being bent. At this time, the piezoelectric element 11 bends in a relatively short time.

  The voltage generated when these are bent changes in polarity depending on the time difference of bending and the direction in which the piezoelectric element 11 bends. Therefore, in order to efficiently extract the electric energy from each piezoelectric element 11, a separate electric Use a circuit. FIG. 4 shows an example in which the separate piezoelectric elements 11a, 11b, and 11c have a circuit for taking out electrical energy separately, and the circuit is led to a common rectifier circuit. FIG. 5 shows an example in which the electrical energy from the piezoelectric elements 11a, 11b, and 11c is processed using an individual bridge rectifier circuit, and this processing is preferably performed. As a result, it is possible to prevent a reverse polarity voltage from being applied to a load, a storage battery or the like, and to obtain an electromotive force more efficiently. The elastic body 18 is contracted and displaced, the displacement increases, the repulsive force increases, the displacement due to inversion is allowed, and the shim can be reversed in the reverse direction after the reversal. Select one with this elastic modulus. As the elastic body 18, besides a helical spring (coil spring), a buckling spring, a plastic ball, a rubber elastic ball, a flat spring, or the like is used. A combination of these can also be used.

  When a helical spring (coil spring) is used for the elastic body 18, the applied external force F is removed after the piezoelectric element 11 is reversed, and the force acting on the helical spring (coil spring) becomes smaller than a certain level. In addition, the helical spring (coil spring) tries to return to its original shape instantly. At that time, the piezoelectric element 11 also returns from the shape shown in FIG. 1C to the original shape shown in FIG. Thus, even when the helical spring (coil spring) returns to its original shape, the piezoelectric element 11 is bent suddenly by reverse reversal of the shim, thereby generating a large electric energy in the piezoelectric element 11 and taking it out. .

  In the case of returning to the state shown in FIG. 1C from FIG. 1C, buttons for applying external force to the entire piezoelectric element are attached on the upper side of the support member 14, and the buttons are within a certain range. It is desirable to determine so that the support member 14 can be restored to the initial position.

  FIG. 3 shows a plan view of the schematic structure of the power generation device 20 and a front view showing its operating state. The power generation device 20 arranges a plurality of fan-shaped piezoelectric elements 21 having substantially the same size so that the radial direction of the fan-shaped piezoelectric elements is the radial direction of one assumed circle, The cylindrical support portion 24 that integrally supports the ends close to the center of the circle of the piezoelectric element and the other end of the circumferential portion of the adjacent piezoelectric element are narrowed to be bent to the same side of the circle. And another ring-shaped support portion 26 that flexibly supports the piezoelectric element at the other end. Further, adjacent fan-shaped piezoelectric elements 21 are connected by a connecting portion 25, the bending of each piezoelectric element 21 is reinforced, and the tension can be adjusted during bending and reversal. The connecting portion 25 is made of steel. By causing the one support portion 24 to reciprocate in a direction perpendicular to the circle, the piezoelectric element 21 is repeatedly bent and inverted to generate electric power. The piezoelectric element 21 is configured by being attached to a shim. The part (piezoelectric part) which exhibits the piezoelectric effect of a piezoelectric element has a piezoelectric plate or a piezoelectric plate and a metallic piezoelectric element shim plate (not shown) adhered thereto and an adhesive layer (not shown) between them. Are also preferably used.

  As shown in FIG. 3B, the piezoelectric element 21 has a convex shape including the support portion 24 in a state where no external force is applied to the piezoelectric element 21. The piezoelectric element 21 is bent and invertible. Furthermore, the opposite side where the external force of the support portion 24 that integrally supports the piezoelectric element 21 does not directly act is in contact with a helical spring (coil spring), and the bottom portion of the helical spring (coil spring) is in contact with the support member 26 and the support portion and the piezoelectric element. It has a structure that gives a restoring force to the entire element.

  In the power generator 20 configured as described above, when the external force F acts on the support portion 24 so as to shift from the state shown in FIG. 3B to the state shown in FIG. 3C, the external force F is piezoelectric. When the size is such that the entire element can be reversed, the entire piezoelectric element is inverted and deformed, and the helical spring (coil spring) 28 is contracted and deformed, as shown in FIG. At this time, since the entire piezoelectric element is rapidly inverted, an electromotive force is generated in each piezoelectric element 21. The elastic body contracts and displaces, the displacement increases, the repulsive force increases, the displacement due to reversal is allowed, and the entire piezoelectric element can be reversed in the reverse direction after reversal. An elastic body having an elastic modulus capable of such an action is selected. In addition to the spring-like elastic body, a rubber elastic ball, a buckling spring, a plastic ball, a helical spring (coil spring), a flat spring, or the like is used as the elastic body. A combination of these can also be used.

  When the helical spring (coil spring) 28 is used, when the applied external force F is removed after the piezoelectric element is reversed and the force acting on the helical spring (coil spring) becomes smaller than a certain magnitude, The spring (coil spring) tries to return to its original shape instantly. At that time, the entire piezoelectric element also returns to the original shape shown in FIG. Thus, even when the helical spring (coil spring) returns to its original shape, the entire piezoelectric element bends suddenly due to reverse reversal of the entire piezoelectric element, thereby generating and taking out large electric energy in the entire piezoelectric element. Can do. In the case of the power generation apparatus 20, as in the power generation apparatus 10, separate electric circuits are used for the individual piezoelectric elements 21. In the power generation device 20, FIG. 4 is read as an example in which the piezoelectric element 21 having the separate shim 23 has a circuit for taking out electric energy separately, and the circuit is led to a common rectifier circuit. Can do. FIG. 5 can also be read as an example where electrical energy from a piezoelectric element 21 having a separate shim 23 is processed using a separate bridge rectifier circuit. It is preferable to perform the treatment in this way. As a result, it is possible to prevent a reverse polarity voltage from being applied to a load, a storage battery or the like, and to obtain an electromotive force more efficiently.

  6 has a structure in which the six power generation devices 10 in FIG. 1 are provided with five connecting portions 39 between support members 34 and stacked in series. The opposite surface of the connecting portion 39 of the supporting portion 34 of the power generation device 10 at the stacked end is in contact with the elastic body 37, and the opposite surface of the connecting portion 39 of the supporting portion 34 of the power generating device 10 at the other stacked end is a push rod. It is in contact with 38. FIG. 6 shows a state in which each power generation device is inverted by pressurization of the push rod 38 and the restoring force of the elastic body 37 is increased. When the pressing force of the push bar 38 is reduced, the push bar 38 is restored in the opposite direction by the restoring force from the elastic body 37. Electric power is repeatedly generated by the reciprocating motion of the push bar 38 and the support portion 34 due to repeated pressurization.

  FIG. 6 shows the power generating device 10 shown in FIG. 1 in which the support portion 16 is a cylindrical support portion 46 and a push bar 48 is provided in contact with the support portion 44 at the center of the circle. It is the connected power generator 40. The cylindrical support part 46 cuts a groove such as a V-shaped valley in the inner circumferential portion of the cylindrical cross section, and receives and supports the other end of the piezoelectric element. In this case, the connecting portion 45 can be configured with a wire or the like as necessary. The sliding partition 49 forms one partition of the cylinder 50 that draws in tide. As shown in FIG. 7, when the amount of tide taken from the tide entrance of the cylinder 50 increases, the air trapped in contact with this compresses and the compression force pushes up the sliding partition 49. This applied pressure is transmitted through the push rod 48 and the support portion 44, and the entire piezoelectric element is bent and inverted to generate power. When the amount of tide taken from the tide inlet of the cylinder 50 decreases, the trapped air expands and the pressure decreases, so that the sliding partition wall 49 descends. Along with this, the push rod 48 and the support portion 44 descend, and the entire piezoelectric element is reversed in the reverse direction. By this reciprocating motion, power generation is repeated.

  The present invention is suitable for a wide range of applications from portable electronic devices such as mobile phones, portable game machines, and notebook computers to large tidal power generation. Moreover, it is not limited to such a use, It is suitable also as an on-site electric power generating apparatus of the place where a vibration generate | occur | produces by natural force or human equipment.

The figure showing the schematic structure and operation state of a power generator. The top view of schematic structure of another electric power generating apparatus. A diagram showing the schematic structure and operating state of yet another power generator The figure showing the electric circuit of a power generator. The figure showing another electric circuit of an electric power generating apparatus. Furthermore, sectional drawing showing the schematic structure of another electric power generating apparatus. The schematic structure figure showing the embodiment of a tidal power generator.

Explanation of symbols

10, 10 ', 20, 30, 40; power generator
11, 11a, 11b, 11c, 21, 31, 41; Piezoelectric element
12, 22: Piezoelectric plate
13, 23, 33; Sim
14, 24, 34, 44; support member (circular center side)
15, 25, 35, 45; connecting part
16, 26, 36, 46; Other support members (circumferential side)
17: Support groove
18, 28; elastic body
19; Elastic body for connecting parts
37; Elastic body
38, 48; push rod
39; articulated part
49; sliding partition
50; cylinder

Claims (4)

A piezoelectric element that is bonded to a plurality of rectangular or fan-shaped shims having substantially the same dimensions is assumed to have a radius of one circle in which the longitudinal direction of the rectangular piezoelectric element or the radial direction of the sector-shaped piezoelectric element is assumed. A piezoelectric device arranged in a direction,
A support portion that integrally supports an end portion of the piezoelectric element close to the circular center portion;
Another support portion that flexibly supports the other end of the piezoelectric element so that the other end of the circumferential portion of the adjacent piezoelectric element is narrowed and bent to the same side of the plane including the circle; ,
Including
By reciprocating the one support portion relative to the other support portion in a direction perpendicular to the circle, the piezoelectric element is repeatedly bent and inverted to the opposite side of the plane including the circle. And a power generation device characterized by generating power.   The power generation device according to claim 1, wherein a connecting portion that generates tension between the piezoelectric elements is mounted instead of or together with the other supporting portion.   The power generation device according to claim 1 or 2, wherein a part or all of the other end close to the circumferential portion is connected in the vertical direction of the plane including the circle by being connected by the one support portion, and a plurality of layers are stacked. A power generation apparatus, wherein the power generation apparatus is supported by another common support member and generates power by reciprocating the stacked support portions in conjunction with each other.   4. The power generation according to claim 1, wherein the other supporting member is a partition wall in the cylinder, or is connected to the cylinder and is driven by a pressure change due to movement of a fluid guided into the cylinder. apparatus.