JP2006158112A - Piezoelectric power generation mechanism and wireless switch utilizing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a piezoelectric power generation mechanism in which energy loss is reduced when an external driving force acts and to generate power with high efficiency for the external driving force. <P>SOLUTION: The piezoelectric power generation mechanism comprises a piezoelectric power generation element 1 including a piezoelectric element 1a and a resiliently deformable supporting plate 1b bonded with the piezoelectric element 1a, and a spring drive section 2 having one fixed end 2a and the other free end 2b. The spring drive section 2 holds the supporting plate 1b of the piezoelectric power generation element 1 fixedly at a fixing point 1c. When an external driving force acts on the free end 2b and then it is released, the spring drive section 2 oscillates. The piezoelectric power generation element 1 oscillates by receiving oscillation from the spring drive section 2, and the supporting plate 1b and the piezoelectric element 1a bend to induce a stress in the piezoelectric element 1a thus generating power. Since oscillation energy is preserves as the potential energy of each spring, self-attenuation of oscillation is retarded and power can be generated efficiently. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a piezoelectric power generation mechanism and a small and thin wireless switch using the same.

As a power generation mechanism using a conventional piezoelectric element, as disclosed in Patent Document 1, a piezoelectric element and a support plate are laminated, and a cantilever structure in which one end is displaceable and the other end is a support end. There is known a piezoelectric power generation mechanism including a power generation element. This power generating element transmits external mechanical energy from the support end, and an excitation force acts due to the inertia of the weight provided at the free end. Generates electric energy by bending.
Japanese Patent Laid-Open No. 11-136964

  However, in the vibration of the piezoelectric power generating element having the cantilever structure as described above, this vibration energy leaks and is lost at the support end, so that it tends to self-dampen and the vibration does not last long. In order to reduce this energy loss, the support rigidity at the support end may be increased, but the support structure is increased in size.

  The present invention has been made in view of the above problems, solves the problem of the cantilever structure, reduces energy loss when an external driving force is applied, continues to vibrate longer, and is driven from the outside. An object of the present invention is to provide a piezoelectric power generation mechanism capable of generating power with high efficiency with respect to force.

  In order to achieve the above object, a first aspect of the present invention is directed to a piezoelectric power generating mechanism including a piezoelectric power generating element that generates power by elastic vibration based on an external drive input. A piezoelectric power generation element having an elastically deformable support plate and one end having a fixed end and the other end being a free end, and having a spring property. A spring drive unit that holds a support plate of the element, the spring drive unit vibrates when an external drive force acts on the free end, and the piezoelectric power generation element receives vibration of the spring drive unit. Power generation.

  According to a second aspect of the present invention, in the first aspect of the invention, the natural frequency of the piezoelectric power generating element and the natural frequency of the spring driving unit are the same, and the piezoelectric power generating element and the spring driving unit are It is configured to resonate.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the spring drive unit holds and holds the central portion of the piezoelectric power generating element, and the piezoelectric power generating element is in contact with the central portion. At least two or more vibrating pieces are arranged in a symmetric system.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the piezoelectric power generating element ensures the symmetry of vibration of the vibration piece in a free vibration part other than the part where the spring drive unit is fixed. As described above, the configuration has a weight having at least one mass.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the spring drive portion is formed of a coil spring, and the external drive force is released after the coil spring is compressed or extended by the external drive force. By doing so, it is configured to operate with vibration.

  According to a sixth 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 mechanism according to any of the first to fifth aspects as a power source. The configuration is as follows.

  According to the invention of claim 1, when the external driving force is applied and the spring driving portion vibrates, the vibration vibrates the elastically deformable support plate to which the piezoelectric element is fixed. The energy of vibration is stored as the potential energy of the springs of each other, self-damping is reduced, the vibration of the piezoelectric power generating element continues for a long time, and it becomes possible to generate power with high efficiency with respect to external driving force.

  According to the invention of claim 2, since the spring drive unit and the piezoelectric power generating element are resonated to generate power, the vibration of the piezoelectric power generating element is less attenuated, the vibration having a large amplitude continues for a long time, and the driving force from the outside is increased. On the other hand, it is possible to generate power with high efficiency.

  According to the invention of claim 3, since the piezoelectric power generating element has at least two or more vibrating pieces arranged in a symmetric system and the spring drive portion is fixed to the center portion, more efficient and large power generation can be obtained. It becomes possible.

  According to the invention of claim 4, since the weight is provided at the free vibration portion of the piezoelectric power generating element, the weight of the piezoelectric power generating element is adjusted by adjusting the weight of the weight regardless of the size of the piezoelectric power generating element. The frequency can be set, and the piezoelectric power generation mechanism can be reduced in size.

  According to the invention of claim 5, since the spring drive part is a coil spring, the loss of vibration energy is small, the vibration of the piezoelectric power generation element continues for a long time, and power can be generated with high efficiency with respect to the drive force from the outside. It becomes possible. In addition, the space required for housing the spring drive unit is reduced, and the piezoelectric power generation mechanism can be reduced in size.

  According to the invention of claim 6, since the piezoelectric power generation mechanism capable of generating power efficiently with respect to the input external driving force is used as the power source of the wireless switch, it is not necessary to replace the battery and the convenience of the wireless switch is improved. Become.

  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 the piezoelectric power generation mechanism according to the first embodiment. This piezoelectric power generation mechanism includes a piezoelectric power generation element 1 and a spring drive unit 2. The piezoelectric power generation element 1 includes a plate-like piezoelectric element 1a, a support plate 1b to which the piezoelectric element 1a is fixed and elastically deformable, and an electrode (not shown) provided on the piezoelectric element 1a. The spring drive unit 2 is a fixed end 2a with one end fixed, and the other end is a free end 2b. The support plate 1 b of the piezoelectric power generating element 1 is fixed to the spring driving unit 2 at the fixing point 1 c, and the spring driving unit 2 holds the piezoelectric power generating element 1.

  Both ends of the support plate 1b of the piezoelectric power generating element 1 become free vibration parts 1d. In the piezoelectric power generating element 1, each of the vibrating plate A from the fixing point 1c to the free vibration parts 1d at both ends can vibrate (see the figure). Part indicated by a two-dot chain line). The spring drive unit 2 is displaced by the external drive force acting on the free end 2b, and generates a restoring force in a direction opposite to the direction of the external drive force. Thereafter, when the external driving force is released, the restoring force vibrates in the direction of the arrow in the figure. The vibration of the spring drive unit 2 is transmitted to the piezoelectric power generation element 1, and the vibration piece A of the piezoelectric power generation element 1 receives this vibration and vibrates in the direction of the arrow in the figure. At this time, the piezoelectric power generating element 1 generates electric power when the support plate 1b and the piezoelectric element 1a are bent and stress is generated in the piezoelectric element 1a, and this electric power is drawn through the electrodes.

  In the piezoelectric power generation mechanism according to this embodiment, the external driving force acts on the free end 2b to vibrate the spring drive unit 2, and this vibration vibrates the support plate 1b of the piezoelectric power generation element 1. It works by. By doing so, the vibration energy of the support plate 1b and the spring drive unit 2 is stored as the positional energy of the springs, so that the amount of vibration energy loss at the fixed end 2a of the spring drive unit 2 is reduced. The self-attenuation is reduced, and the vibration of the piezoelectric power generating element 1 continues for a long time, so that power can be generated with high efficiency with respect to the external driving force.

  Here, the piezoelectric power generation mechanism can be configured such that the natural frequency of the piezoelectric power generation element 1 and the natural frequency of the spring drive unit 2 coincide. When configured so that the natural frequencies coincide with each other, the piezoelectric power generating element 1 and the spring drive unit 2 resonate. Therefore, the piezoelectric power generating element 1 continues to vibrate with a large amplitude for a long time and efficiently generates large power. Can be obtained.

  FIG. 2 shows a schematic configuration of the piezoelectric power generation mechanism according to the second embodiment. Hereinafter, the same components as those of the above-described embodiment will be denoted by the same reference numerals, description thereof will be omitted, and differences will be described. In the present embodiment, the piezoelectric power generating element 1 has a configuration in which four vibrating pieces A are arranged in a single plane in a symmetrical system with respect to the central portion. In this piezoelectric power generation mechanism, the spring drive unit 2 fixes and holds the support plate 1b with the central portion of the piezoelectric power generation element 1 as the fixing point 1c. This piezoelectric power generation mechanism operates in the same manner as the piezoelectric power generation mechanism in the first embodiment and can generate power efficiently. By generating power with the four vibration pieces A, a large amount of power is generated. Obtainable. Here, in order to obtain such an effect, it is sufficient that at least two resonator elements are arranged in a symmetrical system in the piezoelectric power generating element 1, and can be set as appropriate.

  FIG. 3 shows a schematic configuration of the piezoelectric power generation mechanism according to the third embodiment. This piezoelectric power generation mechanism has weights 1e having masses at free vibration portions 1d at both ends of the support plate 1b of the piezoelectric power generation element 1, respectively. The piezoelectric power generating element 1 has a configuration in which two vibrating pieces A are arranged in a symmetrical system with respect to the central portion, and the weight 1e is provided so as to ensure the symmetry of vibration of the vibrating piece A. Yes. In this way, by providing the weight 1e in the free vibration portion 1d, the natural frequency of the piezoelectric power generation element 1 is set by adjusting the weight of the weight 1e regardless of the size of the piezoelectric power generation element 1. can do. For example, if the piezoelectric power generating element 1 is made small for the purpose of downsizing the piezoelectric power generating mechanism, the natural frequency increases, and the natural frequency of the spring driving unit 2 is also high in order to resonate with the spring driving unit 2 as described above. It is necessary to configure so that However, by providing the weight 1e, the natural frequency of the piezoelectric power generation element 1 and the spring drive unit 2 can be adjusted to be low by increasing the mass of the weight 1e. That is, by providing the weight 1e as described above and adjusting the weight 1e to an appropriate mass, the piezoelectric power generation mechanism can be reduced in size while maintaining the natural frequency and resonance conditions.

  FIG. 4 shows a schematic configuration of the piezoelectric power generation mechanism according to the fourth embodiment. In this embodiment, the spring drive part 2 consists of a coil spring. The spring drive unit 2 (coil spring 2) has a free end 2b as a fixing point 1c where the free end 2b is fixed to the support plate 1b of the piezoelectric power generating element 1, and an external driving force is input to the free end 2b, thereby the coil spring 2 Compresses or extends in the direction of the arrow in the figure, and generates a restoring force in the direction opposite to the direction of the external driving force. When the external driving force is released, the coil spring 2 vibrates in the direction of the arrow in the figure with this restoring force, and the piezoelectric power generating element 1 is vibrated by this vibration to generate electric power. Thus, by making the spring drive unit 2 a coil spring with little loss of vibration energy, the vibration of the piezoelectric power generation element 1 continues for a long time, and it is possible to generate power efficiently with respect to the drive force input from the outside. Become. Further, the space necessary for housing the spring drive unit 2 is reduced, and the piezoelectric power generation mechanism can be reduced in size.

  FIG. 5 shows a schematic configuration of the piezoelectric power generation mechanism according to the fifth embodiment. In the present embodiment, the spring driving unit 2 is formed of a coil spring as in the fourth embodiment, and the coil spring 2 holds the support plate 1b of the piezoelectric power generating element 1 with the central portion of the piezoelectric power generating element 1 as a fixing point 1c. The piezoelectric power generating element 1 has a configuration in which four vibration pieces A are arranged in a symmetric system with respect to the central portion. With this configuration, the piezoelectric power generation mechanism can operate in the same manner as described above to generate power efficiently, and can generate large power by generating power with the four vibrating bars A. . At this time, in order to obtain such an effect, the number of vibrating pieces A arranged in a symmetric system in the piezoelectric power generation element 1 may be at least two, and can be set as appropriate.

  Next, with reference to FIG. 6, an embodiment of a wireless switch for a wireless communication apparatus provided with the piezoelectric power generation mechanism of the first to fifth embodiments will be described. This wireless switch operates using power generated by the piezoelectric power generation mechanism as a power source, and transmits a signal to the controlled device. FIG. 6 shows a wireless switch including a piezoelectric power generation mechanism in which the spring drive unit 2 is a coil spring, which has the same configuration as that of the fourth embodiment. In this wireless switch, the fixed end 2a of the piezoelectric power generation mechanism and the wireless communication device 50 are fixed to the casing 51, and the electrode 1f provided on the piezoelectric power generation element 1 and the wireless communication device 50 are connected by a wire 55. Is done. A switch handle 52 is provided on the casing 51 via a hinge 54 so as to be rotatable in the direction of the arrow in the figure. The pressing means 53 of the piezoelectric power generating element 1 is fixed to the switch handle 52. When the switch handle 52 is pressed in the direction of the white arrow in the figure, the pressing means 53 pushes the free end 2b of the piezoelectric power generating mechanism. Press.

  When the operation load from the outside is applied to the switch handle 52 and is pressed down, when the free end 2b of the piezoelectric power generation mechanism is pressed by the pressing means 53, the spring drive unit 2 (coil spring 2) is outlined. It compresses in the direction of the arrow and generates a restoring force in the opposite direction. When the operating load applied to the switch handle 52 disappears and the external driving force applied to the free end 2b is released, the coil spring 2 vibrates in the black arrow direction with this restoring force. The piezoelectric power generating element 1 receives the vibration of the coil spring 2 and vibrates, and the support plate 1b and the piezoelectric element 1a are bent to generate power by generating stress in the piezoelectric element 1a. Thus, the electric power generated by the piezoelectric power generation mechanism is supplied from the electrode 1 f to the wireless communication device 50 through the wiring 55. 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. In this way, the power supply of the wireless switch is a piezoelectric power generation mechanism that can generate power efficiently with respect to the external driving force that is input, thereby eliminating the need for battery replacement and the like, thus improving the usability of the wireless switch. It becomes possible.

  Here, in the case where the piezoelectric power generation mechanism described in each of the above-described embodiments is provided as a power source for the wireless switch, the arrangement of the piezoelectric power generation mechanism and the pressing unit 53 in the configuration of the wireless switch as described above may be changed. Good. That is, when an operation load is applied to the switch handle 52, the piezoelectric power generation is performed such that the pressing means 53 presses the free end 2b of the piezoelectric power generation mechanism and the spring drive unit 2 is displaced in the vibrating direction. The spring drive unit 2 of the mechanism is fixed to the casing 51, and the position of the pressing means 53 is changed. By configuring the wireless switch in this way, the piezoelectric power generation mechanism can be driven.

  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, the spring drive unit 2 that holds the piezoelectric power generating element 1 may be a torsion spring. At this time, the external drive force acts to vibrate in the direction in which the spring drive unit is twisted, and the vibration is received to receive the piezoelectric element. The piezoelectric power generation mechanism is configured such that the power generation element 1 vibrates.

1 is a perspective view of a piezoelectric power generation mechanism according to a first embodiment of the present invention. The top view of the piezoelectric power generation mechanism which concerns on the 2nd Embodiment of this invention. The perspective view of the piezoelectric power generation mechanism which concerns on the 3rd Embodiment of this invention. The perspective view of the piezoelectric power generation mechanism which concerns on the 4th Embodiment of this invention. The perspective view of the piezoelectric power generation mechanism which concerns on the 5th Embodiment of this invention. The sectional side view of the wireless switch provided with the piezoelectric type electric power generation mechanism comprised by the same structure as the said 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric power generation element 1a Piezoelectric element 1b Support plate 1c Fixing point 1d Free vibration part 1e Weight 2 Spring drive part 2a Fixed end 2b Free end A Vibrating piece

Claims (6)

A piezoelectric power generation mechanism including a piezoelectric power generation element that generates power by elastic vibration based on an external drive input,
A piezoelectric power generation element having a plate-like piezoelectric element and a support plate to which the piezoelectric element is fixed and elastically deformable;
One end is a fixed end, the other end is a free end, and is made of a member having a spring property, and is provided with a spring drive unit that holds the support plate of the piezoelectric power generating element near the other end,
The spring drive unit vibrates when an external drive force acts on the free end,
The piezoelectric power generation mechanism is characterized in that the piezoelectric power generation element generates electric power by receiving vibration of the spring drive unit.   2. The piezoelectric device according to claim 1, wherein a natural frequency of the piezoelectric power generation element matches a natural frequency of the spring driving unit, and the piezoelectric power generation element and the spring driving unit resonate. Type power generation mechanism. The spring drive unit holds and holds the central portion of the piezoelectric power generation element,
3. The piezoelectric power generation mechanism according to claim 1, wherein the piezoelectric power generation element has at least two vibrating pieces arranged symmetrically with respect to a central portion thereof. 4.   The piezoelectric power generating element is provided with a weight having at least one mass so as to ensure the symmetry of vibration of the resonator element in a free vibration part other than the part to which the spring drive unit is fixed. 4. The piezoelectric power generation mechanism according to claim 3, further comprising:   5. The spring drive unit comprises a coil spring, and the coil spring is compressed or extended by an external drive force, and then vibrates and operates by releasing the external drive force. The piezoelectric power generation mechanism according to any one of the above. A wireless switch for a wireless communication device that operates using the electric power generated by the piezoelectric power generation mechanism according to any one of claims 1 to 5 as a power source and transmits a signal to a controlled device.

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