JP2012104691A - Vibration power generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration power generating device capable of controlling resonance frequency and fetching vibrational energy in a curved surface shape.SOLUTION: The vibration power generating device comprises: a vibration power generating element 1; a support substrate 2 that is provided with the vibration power generating element 1 on at least one surface thereof and has a curved surface shape; and a housing 4 that has the support substrate 2 and the vibration power generating element 1 therein, fixes the support substrate 2 and has a curved surface shape in the same direction as the support substrate 2. The rigidity of the support substrate 2 is smaller than that of the housing 4.

Description

  The present invention relates to a vibration power generation device that converts kinetic energy such as vibration into electric energy.

  As one of the measures to reduce CO2 emissions that are a cause of global warming, energy harvesting that converts solar energy, geothermal energy, wind power, tides and other energy into electrical energy is drawing attention. ing.

  Also in portable devices and the like, it is required to secure power supply such as reducing the charging frequency after achieving high performance, miniaturization, thinning, and weight reduction that are easy for the user to use.

  In addition, the use of portable devices has been increased along with the increase in performance and the usage time has been extended for a long time, and the demand for electric power has been steadily increasing. However, the capacity of batteries such as lithium ions used as power sources for portable devices has hardly increased, and expectations for power supply in a ubiquitous environment are very high.

  Regarding power supply in a ubiquitous environment, Patent Document 1 proposes an invention for extracting power from mechanical vibration energy. A piezoelectric power generation mechanism described in Patent Document 1 includes a vibrator that forms an unbalanced mass moment near the center of a rod-shaped spring material held at both ends, a piezoelectric element that generates power by deformation, and It has. Then, when receiving vibration from the outside and the spring material excites torsional vibration by the mass of the vibrator, the piezoelectric element generates power of 0.1 to 0.6 μW.

  When the piezoelectric power generation mechanism proposed in Patent Document 1 is installed in a building such as a building or a bridge, when the building vibrates at a low frequency due to the passage of a wind or a surrounding moving body, The piezoelectric power generation mechanism can generate electric power. And in patent document 1, it becomes possible to monitor the stress etc. which are added to a building etc. in the long term by using the generated electric power for the power source for an acceleration sensor or a strain sensor attached to the building, It is said that damage that can occur can be predicted.

  In recent years, in order to efficiently extract electric power from mechanical vibration energy, a technique for changing the resonance frequency of the vibrating body (vibrator) in accordance with the vibration frequency of the mechanical energy is required.

For example, in the vibration power generation device proposed in Patent Document 2, one end of a vibrating body is fixed, and a movable magnet and a fixed magnet facing the other end are provided at the other end. And, it is described that the resonance frequency of the vibrating body is controlled by changing the rigidity of the coil spring provided at the end of the vibrating body to make the distance between the movable magnet and the fixed magnet variable.
Moreover, in patent document 3, the output value converted into the electrical energy from the vibration energy is detected. And it is described that the resonance frequency is controlled by changing the spring constant k and the damping coefficient c of the spring attached to the vibrating body based on the detected electric energy, and the output of the electric energy is set to the maximum.

WO2008 / 053835 JP 2001-157433 A Special table 2008-536470 gazette

  The above power generation device has begun to be applied to various fields, and it is required to extract electric power from vibration energy not only in a thin shape and a small size but also in a curved surface shape. However, the mounting structures described in Patent Documents 2 and 3 are intended for a linear housing, and when applied to a curved surface, there is a problem that the dead space becomes large and the device becomes thick. .

  Further, when vibration energy is converted into electric power energy, the vibration energy is not a fixed frequency and amplitude, and is not continuously given. For this reason, the system for controlling the frequency by feeding back the output value of the electric energy described in Patent Document 3 has a small effect and has a problem in terms of output accuracy.

  The objective of this invention is providing the vibration electric power generation device which solves the subject mentioned above.

  The vibration power generation device according to the present invention includes a piezoelectric element, a piezoelectric element provided on at least one surface, a support substrate having a curved surface, a support substrate and a piezoelectric element, and a support substrate fixed to the support substrate. And a support body having a curved surface shape in the same direction, and the rigidity of the support substrate is smaller than the rigidity of the support body.

  According to the present invention, there is provided a vibration power generation device capable of controlling a resonance frequency and extracting vibration energy even in a curved surface shape.

It is a top view of the vibration power generation device in a 1st embodiment. It is sectional drawing of the vibration electric power generation device in 1st Embodiment. It is a perspective view which shows the connection relation of the vibration electric power generating element in 1st Embodiment, and a support substrate. It is a top view of the vibration electric power generation device in 2nd Embodiment. It is a top view of the vibration power generation device in a 3rd embodiment. It is a top view of the vibration electric power generation device in 4th Embodiment. It is sectional drawing of the vibration electric power generation device in 4th Embodiment. It is a perspective view which shows the connection relation of the vibration electric power generating element in 4th Embodiment, and a support substrate.

  [First Embodiment] A preferred embodiment for carrying out the present invention will be described below with reference to the drawings. However, the preferred embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following.

  [Description of Configuration] FIG. 1 is a plan view showing the configuration of this embodiment, and FIG. 2 is a cross-sectional view of FIG. As shown in FIGS. 1 and 2, the vibration power generation device 10 in this embodiment includes at least a vibration power generation element 1, a support substrate 2, a substrate fixing portion 3, and a housing 4. In addition, in order to understand easily, in FIG. 1, the components provided in the housing 4 are also shown by the solid line. FIG. 2 is a cross-sectional view taken along the line AA ′ along the curved support substrate 2.

  The vibration power generation element 1 is not particularly limited as long as it converts vibration energy into electric energy. The vibration power generation element 1 in the present embodiment uses a thin film piezoelectric film in which electrodes are formed on the front and back surfaces of a thin film film-like ferroelectric. The vibration power generation element 1 is electrically connected to the central portion of the support substrate 2 by a conductive paste such as a conductive adhesive.

  The support substrate 2 has a planar shape, and the vibration power generation element 1 is mounted on a central portion on at least one surface. The support substrate 2 has a quadric surface at least partially. The secondary curved surface is a shape in which both end portions of the support substrate 2 are curved in one of the surface directions on which the vibration power generation element 1 is mounted. In other words, both ends of the support substrate 2 are curved in one direction with a predetermined radius of curvature, and the vibration power generation element 1 is mounted on a surface perpendicular to the curve direction of the support substrate 2.

  The support substrate 2 may be a general wiring substrate such as a glass epoxy substrate, ABS (acrylonitrile / butadiene / styrene resin), PET (polyester), PEN (polyethylene naphthalate), PC (polycarbonate), PI (polyimide). The wiring may be formed by printing and sintering a conductive paste or the like on an insulating plate such as PTFE (polytetrafluorothien).

  FIG. 3 is a perspective view showing a connection relationship between the vibration power generation element 1 and the support substrate 2. As shown in FIG. 3, since the vibration power generation element 1 is mounted on a surface perpendicular to the bending direction of the support substrate 2, the vibration direction is also in the bending direction of the support substrate 2 as indicated by the arrows. Visible in the vertical direction. For this reason, it is preferable for the support substrate 2 to vibrate when the thickness in the bending direction is increased and the thickness in the direction perpendicular to the bending direction is decreased. In addition, it is preferable that the curved surface of the support substrate 2 is a curved surface with the same curvature radius inside and outside.

  The housing 4 has a shape with a secondary curved surface that is curved in the same direction as the support substrate 2, and the vibration power generation element 1 and the support substrate 2 are provided inside. The support substrate 2 is connected to the housing 4 at at least two substrate fixing portions 3. The substrate fixing portion 3 is fixed to the housing 4 by screwing through a through hole provided in the support substrate 2.

  The bending rigidity of the support substrate 2 is smaller than the bending rigidity of the housing 4. Further, the curvature radius of the support substrate 2 is smaller than the curvature radius of the housing 4. The support substrate 2 is provided with electrode pads (not shown) in the vicinity of the region where the vibration power generation element 1 is mounted and in the vicinity of the substrate fixing portion 3.

  The housing 4 may be provided with a sensor device, a wireless communication device, and an antenna inside. Also, a rectifier circuit that converts an alternating voltage generated by the vibration power generation element 1 into a direct current voltage, a regulator that stabilizes the direct current voltage, a voltage converter that converts the direct current voltage into a predetermined voltage, and an electric storage that stores electric charge after the voltage conversion. Means may be provided. In addition, an electronic board on which a device power supply controller for adjusting voltage is mounted, a display device such as liquid crystal or electronic paper, and an input device such as a key switch and a touch panel (not shown) can be provided.

  The vibration power generation device 10 and the electronic board may be directly connected by a wiring cable. However, since the vibration displacement amount is large in the vicinity of the vibration power generation device 10, the vibration power generation device 10 is connected in the vicinity of the substrate fixing portion 3 having a small vibration displacement amount. It is preferable. Further, the support substrate 2 and the electronic substrate may be shared, that is, the vibration power generation device 10 may be mounted on the electronic substrate. However, in the above case, there is a concern that other mounted components may be defective due to positive vibration of the electronic substrate, and therefore it is preferable to place restrictions on the component layout and the like.

  [Explanation of Action] The vibration power generation device 10 of this embodiment vibrates in a direction perpendicular to the direction in which the support substrate 2 is curved by mechanical energy (vibration energy). That is, the support substrate 2 vibrates on the surface on which the vibration power generation element 1 is mounted. The vibration power generation element 1 converts vibration into electric energy.

  Since the support substrate 2 is less rigid than the housing 4, the shape can be easily changed compared to the support substrate 2. For example, even if the casing 4 is deformed by applying a predetermined force from the outside and the curvature radius is changed, the support substrate 2 does not break or come into contact with the housing 4 and can be easily deformed to change the curvature radius. be able to.

  As a result, by changing the radius of curvature of the support substrate 2, the resonance frequency of the support substrate 2 can be easily changed due to changes in the shape of the support substrate 2, tensile stress generated on the outer periphery, and compressive stress generated on the inner periphery. I can do it. That is, the resonance frequency at which the support substrate 2 vibrates can be controlled by the radius of curvature of the support substrate 2.

  [Explanation of Effects] The vibration power generation device 10 according to the present embodiment can easily change the curvature radius of the support substrate 2 by changing the curvature radius of the casing 4 having a curved surface at least partially, thereby easily generating the vibration power generation device. Ten vibration characteristics can be changed. Therefore, the vibration power generation device 10 can efficiently convert vibration energy, which varies depending on the installation location and surrounding conditions, into electric energy.

  Further, the curvature radius of the support substrate 2 is smaller than the curvature radius of the housing 4. Therefore, the arc length between the substrate fixing portions 3 of the support substrate 2 is longer than the arc length between the substrate fixing portions 3 of the housing 4. As a result, the space in the housing 4 can be used effectively, and can be adapted to a lower resonance frequency.

  Therefore, the vibration power generation device 10 in the present embodiment can be used in a small device or the like without forcing the user to perform an operation for power generation such as battery replacement. For example, the present invention can also be applied to a wearable sensor that monitors a human health condition.

  Hereinafter, the effect when applied to a wearable sensor will be described in detail. Wearable sensors are wristwatches and rings equipped with sensors that can measure vital information such as pulse, blood pressure, blood flow, blood saturated oxygen concentration (SpO2), electrocardiogram, and body temperature, and wireless functions that transmit acquired information. It is a small device such as a mold or a bandage mold.

  Wearable sensors can greatly contribute to the development of telemedicine such as early detection of wounds and post-treatment care by continuously monitoring human vital information. However, all of the wearable sensors currently proposed use a button battery as a power source, and battery replacement work every few days has been a major obstacle to popularization, enabling these devices to operate independently. Such a power generation system is needed.

  In addition, small devices that are worn on the body, such as wearable sensors, generally have a curved surface shape in order to ensure compatibility with the body, and are thin in order to be worn comfortably. That was also a necessary condition.

  The vibration power generation device 10 according to the present embodiment can easily change the vibration characteristics of the vibration power generation device 10 by changing the curvature radius of the curved shape of the housing 4. Therefore, vibration characteristics that vary depending on the mounting position and situation of the vibration power generation device 10 can be efficiently converted into electrical energy by changing the curvature radius of the housing and controlling the vibration characteristics. That is, a thin power generation system can be provided even in a wearable sensor having a curved surface shape without forcing the user to perform an operation for power generation such as battery replacement.

  For example, the vibration power generation device 10 according to the present embodiment can be applied to a wearable sensor that is mounted on an ankle of a human body and monitors vital information. The shape of the ankle is not concentric, the front and rear curvature radii are small, and the side curvature radii are large. Therefore, by changing the position where the vibration power generation device 10 is mounted, the radius of curvature of the secondary curved surface of the housing 4 can be changed, and the resonance frequency of the support substrate 2 can be changed.

  Generally, the frequency of vibration energy generated during walking is lower than the frequency of vibration energy generated during travel. Therefore, when walking, the vibration power generation device 10 is attached to a position that comes to the side to lower the resonance frequency, and during traveling, the vibration power generation device 10 is attached to a position that comes to the front or rear surface to increase the resonance frequency, thereby generating power efficiently. Is possible.

  [Second Embodiment] Next, a second embodiment will be described. FIG. 4 is a plan view of the vibration power generation device 10 according to this embodiment.

  [Description of Structure] As shown in FIG. 4, the vibration power generation device 10 of the present embodiment is different from the first embodiment in that a rotary hinge 5 is provided. Other configurations and connection relationships are the same as those in the first embodiment. That is, the vibration power generation device 10 of the second embodiment includes the support substrate 2, the substrate fixing unit 3, and the housing 4.

  As shown in FIG. 4, the vibration power generation device 10 according to the present embodiment is provided inside the curved surface of the housing 4 and between the substrate fixing portions 3. The housing 4 can be rotated and bent about the rotary hinge 5.

  [Description of Action / Effect] The vibration power generation device 10 according to this embodiment can arbitrarily set the bending stress of the casing 4 by providing the casing 4 with the rotating hinge 5. In other words, since the casing 4 can be easily changed in shape by adjusting the curvature radius by providing the rotary hinge 5, the curvature radius of the support substrate 2 can be easily controlled. As a result, the vibration power generation device 10 can adjust the resonance frequency.

  Moreover, since the shape of the vibration power generation device 10 can be easily changed by providing a rotary hinge, the degree of freedom in designing the material and the mounting structure constituting the support substrate 2 and the housing 4 is increased. That is, even if the housing 4 is made of a material having high rigidity, the shape can be easily deformed and the deformed shape can be maintained. Here, from the viewpoint of design and safety, the protective tape 6 may be provided so as to cover the rotary hinge 5.

  [Third Embodiment] Next, a third embodiment will be described. FIG. 5 is a plan view of the vibration power generation device 10 according to this embodiment.

  [Description of Structure] As shown in FIG. 5, the vibration power generation device 10 of this embodiment is different from the first embodiment in the shape of the support substrate 2. Other configurations and connection relationships are the same as those in the first embodiment. That is, the vibration power generation device 10 of the second embodiment includes the support substrate 2, the substrate fixing unit 3, and the housing 4.

  The support substrate 2 of the vibration power generation device 10 in the present embodiment is provided inside the housing 4 and has a polygonal shape along a secondary curved surface of the housing 4. The support substrate 2 may have a shape protruding toward the outer peripheral side of the secondary curved surface of the housing 4.

  The support substrate 4 is connected to the housing 4 through the substrate fixing portions 3 provided at both ends. The distance between the substrate fixing portions 3 of the support substrate 4 may be longer than the arc length between the substrate fixing portions 3 of the housing 4.

  [Description of Functions and Effects] The vibration power generation device 10 according to the present embodiment can obtain the same effect regardless of whether the support substrate 2 has a curved shape or a polygonal shape due to the above structure. As a result, when the support substrate 2 cannot be formed into a curved surface due to a problem in the layout of other mounted components in the housing 4, the polygon 4 can be used to increase the density inside the housing 4 and the device. Further downsizing of the whole can be realized.

  [Fourth Embodiment] Next, a fourth embodiment will be described. FIG. 6 is a plan view of the vibration power generation device 10 according to the present embodiment, and FIG. 7 is a cross-sectional view. For easy understanding, in FIG. 6, the parts provided in the housing 4 are also shown by solid lines. FIG. 7 is a cross-sectional view taken along the line BB ′ along the curved support substrate 2 and is a view seen from the outside in the bending direction.

  [Description of Structure] As shown in FIGS. 6 and 7, the vibration power generation device 10 of the present embodiment is different from the first embodiment in that the vibration power generation element 1 is mounted on the support substrate 2. is there. Other configurations and connection relationships are the same as those in the first embodiment. That is, the vibration power generation device 10 of the second embodiment includes the support substrate 2, the substrate fixing unit 3, and the housing 4.

  In the vibration power generation device 10 according to the present embodiment, the support substrate 2 has a secondary curved surface, and the vibration power generation element 1 is provided on the outer surface of the secondary curved surface. Although not shown, it may be provided on the inner surface of the support substrate 2. That is, the vibration power generation element 1 is provided on the surface in the direction in which the support substrate 2 is curved.

  FIG. 8 is a perspective view showing a connection relationship between the vibration power generation element 1 and the support substrate 2. As shown in FIG. 8, since the vibration power generation element 1 is mounted on the outer surface in the bending direction of the support substrate 2, the vibration direction also vibrates in the bending direction of the support substrate 2 as indicated by the arrow. For this reason, it is preferable to vibrate the support substrate 2 by reducing the thickness in the bending direction and increasing the thickness in the direction perpendicular to the bending direction.

  [Description of Functions and Effects] When vibration energy is applied to the vibration power generation device 10 in the present embodiment, vibration is generated in the direction in which the support substrate 2 is curved, and the vibration power generation element 1 converts the vibration energy into electric energy.

  The vibration power generation device 10 needs to reduce the thickness direction of the secondary curved surface shape of the housing 4 in order to improve the mounting property, but it is not necessary to provide a large restriction in the length direction. In the vibration power generation device 10 of the present embodiment as shown in FIG. 6, mechanical energy is applied in the bending direction of the secondary curved surface of the support substrate 2. Therefore, the thickness direction of the vibration power generation device 10 can be reduced, and the length direction of the support substrate 2 can be increased, so that the power generation amount can be increased.

  Further, in the case of the mounting structure described above, when the bending rigidity of the support substrate 2 exceeds a threshold value, the resonance frequency is remarkably increased due to buckling deformation. Using this characteristic, the required resonance frequency can be changed greatly.

  It should be noted that the present invention is not limited to the configuration of the embodiment described above, and of course includes various variations and modifications that can be made by those skilled in the art within the scope of the present invention. For example, the number of mounted vibration power generation devices 10 is not limited to one, and a plurality of vibration power generation devices 10 may be mounted. Further, the mounting position is not limited to the center of the support substrate, and it is better to mount it at a position where vibration energy is generated strongly.

DESCRIPTION OF SYMBOLS 1 Vibration power generation element 2 Support substrate 3 Substrate fixing | fixed part 4 Housing 5 Rotating hinge 6 Protection tape 10 Vibration power generation device

Claims (10)

A vibration power generation element;
Provide the vibration power generation element on at least one surface, a support substrate having a curved shape,
The support substrate and the vibration power generation element are provided inside, the support substrate is fixed, and a housing having a curved shape in the same direction as the support substrate is provided.
The vibration power generation device according to claim 1, wherein the rigidity of the support substrate is smaller than the rigidity of the housing. A substrate fixing portion for fixing the support substrate and the housing at least at two points;
2. The vibration power generation device according to claim 1, wherein a length between the substrate fixing portions in the support substrate is longer than a length between the substrate fixing portions in the casing.   The vibration power generation device according to claim 2, wherein the curved surface is a quadratic curved surface.   The vibration power generation device according to claim 3, wherein a curvature radius of the support substrate is smaller than a curvature radius of the housing.   The vibration power generation device according to claim 3, wherein the support substrate is a polygon projecting in a bending direction of a secondary curved surface of the housing.   The vibration power generation device according to claim 1, wherein the casing is provided with a rotating hinge between the substrate fixing portions.   7. The vibration power generation device according to claim 1, wherein the vibration power generation element is mounted on a surface of the support substrate in a direction perpendicular to a bending direction of a secondary curved surface.   The vibration power generation device according to claim 1, wherein the vibration power generation element is mounted on an outer surface or an inner surface of the support substrate in a bending direction of the secondary curved surface.   The vibration power generation device according to claim 1, wherein the support substrate is an electronic substrate.   The vibration power generation device according to claim 1, wherein the resonance frequency is changed by changing the shapes of the casing and the support substrate.

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