JP6581816B2 - Vibration power generation apparatus, electronic device, and vibration power generation method - Google Patents

Description

  The present invention relates to a vibration power generation apparatus capable of generating electric power by converting mechanical energy into electric energy, an electronic apparatus including the vibration power generation apparatus, and a vibration power generation method.

  2. Description of the Related Art In recent years, energy harvesting that draws electric power from minute energy such as vibration, heat, light, and electromagnetic waves widely present in the environment and uses it for driving a low-power electronic device (electronic equipment) has attracted attention. Vibration is the most powerful energy source because it can be used at all times even in places where light does not shine among the energy existing in the environment.

  On the other hand, wireless sensors (network sensors) as an example of electronic devices are expected to be applied in a wide range of fields such as medical / health, crime prevention / security, disaster prevention, response to environmental risks, and various production processes of agricultural products in a ubiquitous network society. Has been. If the electronic device itself has a power generation mechanism, it is not necessary to charge or replace the battery, and expansion to a ubiquitous network society is expected.

  Various techniques for generating power using vibration have been studied. For example, a flashlight is disclosed that includes a vibration generator in which a mover having a permanent magnet is provided inside a cylindrical guide member, and a coiled coil is disposed around the guide member (see Patent Document 1). ).

  Further, the vibration power generation apparatus includes a cantilever type vibrating body that is supported by the base body and bends according to mechanical input to the base body, and a piezoelectric element that is joined to the vibrating body and outputs a voltage according to the displacement of the vibrating body. Is disclosed (see Patent Document 2).

JP 2014-64380 A JP 2013-187828 A

  However, in the device of Patent Document 1, in order to generate electric power, the user needs to hold the flashlight by hand and shake the vibration generator so as to vibrate in the axial direction. Active energy. However, in the ubiquitous network society, so-called passive energy using natural energy is desired.

  Moreover, in the apparatus of Patent Document 2, the power that can be taken out is about 50 μW. However, an electronic device such as a wireless sensor requires a function of driving the sensor and transmitting data obtained by the sensor wirelessly, and thus requires a power generation of about mW.

  The present invention has been made in view of such circumstances, and provides a vibration power generation apparatus capable of generating higher power than conventional using passive energy, an electronic apparatus including the vibration power generation apparatus, and a vibration power generation method. The purpose is to do.

  A vibration power generation apparatus according to the present invention is a rectangular plate body having a magnetization direction parallel to the plate surface, arranged to be opposed to a magnet capable of vibration, and one edge side of the magnetization direction of the magnet. A plurality of coils wound along the magnetization direction, and an electromotive force is generated in the coils by electromagnetic induction.

  The vibration power generation method according to the present invention is a rectangular plate body having a magnetization direction parallel to the plate surface, and a step of vibrating a magnet that can vibrate, and arranged opposite to one edge side of the magnetization direction of the magnet And generating an electromotive force by electromagnetic induction in a coil obtained by winding a plurality of conductors along the magnetization direction.

  In the present invention, the vibration power generation device is a rectangular plate having a magnetization direction parallel to the plate surface, and is arranged to be opposed to a magnet capable of vibration and one edge side of the magnetization direction of the magnet. And a coil wound a plurality of times along the magnetization direction. The vibration power generation device can be attached to a vibration source that generates vibration, such as an automobile, an electric product, an electronic device, and a bridge. When the magnet vibrates due to the vibration of the vibration source, the magnetic flux that intersects the coil (area surrounded by the wound conductor) arranged opposite to one edge of the magnetization direction changes, so an electromotive force is generated in the coil by electromagnetic induction. Let Thereby, it is possible to generate electric power with higher power than before by using passive energy.

  The vibration power generator according to the present invention includes a support portion that supports the other edge side opposite to the one edge side of the magnet, and the magnet has a cantilever structure.

  In this invention, the support part which supports the one edge side and other edge side of a magnet is provided. In other words, the other edge side of the magnet is supported by the support portion to form a cantilever structure. A magnet having a cantilever structure can be vibrated by attaching the vibration power generator to a predetermined vibration source. Further, the magnet can be vibrated at the frequency of the vibration source (resonant vibration) by appropriately setting the dimensions of the magnet and making the natural frequency equal to or close to the frequency of the vibration source. As a result, the magnet vibrates (resonant vibration) according to the frequency of the vibration source, and the magnetic flux crossing the coil can be changed by displacing one edge of the magnet substantially parallel to the cross section of the coil.

  The vibration power generation device according to the present invention includes a shaft body in a direction intersecting the magnetization direction at a pair of edge portions parallel to the magnetization direction of the magnet, and the magnet is centered on the shaft body. It is characterized by being able to vibrate.

  In the present invention, the vibration power generator includes a shaft body in a direction intersecting with the magnetization direction in a pair of edge portions parallel to the magnetization direction of the magnet. The magnet can be vibrated around the shaft. The cross-sectional shape of the shaft body may be, for example, a triangle, and torsional vibration using a repulsive force generated by twisting the shaft body can be made possible. The magnet can be vibrated by attaching the vibration power generator to a predetermined vibration source. As a result, the magnet vibrates according to the frequency of the vibration source, and the magnetic flux crossing the coil is changed by displacing one edge side of the magnet and the other edge side opposite to the one edge side substantially parallel to the cross section of the coil. be able to.

  The vibration power generation device according to the present invention includes an elastic member provided on each of the one edge side of the magnet and the other edge side opposite to the one edge side, and a support portion that supports each elastic member. It is characterized by a doubly supported beam structure.

  In this invention, the elastic member provided in each one edge side and other edge side of a magnet, and the support part which supports each elastic member are provided. That is, the one edge side and the other edge side of the magnet are each supported by an elastic member to form a double-supported beam structure. That is, the one edge side and the other edge side of the magnet and the support portion are connected by, for example, an elastic member having a relatively small spring constant. Thereby, the magnet can be vibrated perpendicularly to the magnetization direction. The magnet can be vibrated by attaching the vibration power generator to a predetermined vibration source. As a result, the magnet vibrates according to the frequency of the vibration source, and the magnetic flux crossing the coil is changed by displacing one edge side of the magnet and the other edge side opposite to the one edge side substantially parallel to the cross section of the coil. be able to.

  The vibration power generator according to the present invention is characterized in that the coil is further arranged to face the other edge side opposite to the one edge side of the magnet.

  In the present invention, in the vibration power generator, the coil is further arranged to face the other edge side opposite to the one edge side of the magnet. Thereby, the electric power which can be generated can be increased.

  The vibration power generator according to the present invention is characterized in that a plurality of the coils are arranged along the plate thickness direction.

  In the present invention, the vibration power generator has a plurality of coils arranged along the plate thickness direction. Thereby, the electric power which can be generated can be increased.

  The vibration power generator according to the present invention is characterized in that the conductor has a rectangular cross section, and the coil is wound around the conductor so that the direction of the short side of the conductor is the magnetization direction. To do.

  In the present invention, the conductor has a rectangular cross section, and the coil is wound with the conductor such that the direction of the short side of the conductor is the magnetization direction. Let the dimension of the short side of the conductor be w and the dimension of the long side be d. The resistance R of the conductor is inversely proportional to w × d. As the resistance R of the conductor is smaller, the generated power P can be increased. By winding the conductor so that the direction of the short side of the conductor forms the magnetization direction, for example, compared with the case where the cross section of the conductor is circular or square, the dimension of the magnetization direction of the coil is equivalent. However, since the cross-sectional area of the conductor can be increased and the resistance of the conductor can be reduced, large electric power can be generated.

  In the vibration power generator according to the present invention, the coil has the conductor wound in a rectangular shape, and the length of the edge side of the magnet facing the coil is the edge direction of the wound conductor. It is characterized by being approximately equal to the dimension of.

  In the present invention, the coil is formed by winding a conductor in a rectangular shape, and the length on the edge side where the coil of the magnet is opposed is substantially equal to the dimension in the edge side direction of the wound conductor. As a result, most of the magnetic flux of the magnet intersects the coil, and the magnetic flux density of the magnetic flux intersecting the coil can be increased, so that a large amount of electric power can be generated.

  In the vibration power generation device according to the present invention, the magnet includes a base and a thin film magnet formed on the surface of the base by a physical vapor deposition method.

  In the present invention, the magnet has a base and a thin film magnet formed on the surface of the base by physical vapor deposition. As the substrate, for example, silicon, stainless steel, metal, or metal glass can be used. As the thin film magnet, for example, a rare earth magnet or a noble metal magnet can be used. By using the physical vapor deposition method, a magnet having a required film thickness and high magnetic properties (for example, a high saturation magnetic flux density and a large coercive force) can be realized. Note that the sintered magnet is generally thick and is thinned by polishing or the like up to about 1 mm at most, and oxidative deterioration occurs due to polishing, and magnetic characteristics are also deteriorated.

  An electronic apparatus according to the present invention includes the vibration power generation device according to any one of the above-described inventions.

  In the present invention, the electronic device includes the vibration power generation device. Thereby, the electronic device itself can be provided with a power generation mechanism that can generate higher power than before by using passive energy.

  According to the present invention, it is possible to generate electric power with higher power than before by using passive energy.

It is a block diagram which shows an example of a structure of the sensor apparatus as an electronic device of 1st Embodiment. It is a perspective view which shows an example of the principal part of a structure of the vibration electric power generating apparatus of 1st Embodiment. It is a top view which shows an example of the principal part of a structure of the vibration electric power generating apparatus of 1st Embodiment. It is a side view which shows an example of the principal part of the structure of the vibration electric power generating apparatus of 1st Embodiment. It is sectional drawing which shows an example of a structure of the magnet of 1st Embodiment. It is a front view which shows an example of a structure of the coil of 1st Embodiment. It is sectional drawing seen from the VII-VII line of FIG. It is explanatory drawing which shows an example of the change of the magnetic flux which cross | intersects the coil of the vibration electric power generating apparatus of 1st Embodiment. It is explanatory drawing which shows an example of the change of the electromotive force and generated power which generate | occur | produce in the coil of the vibration electric power generating apparatus of 1st Embodiment. It is explanatory drawing which shows an example of the electric power generated when the vibration frequency by the vibration electric power generating apparatus of 1st Embodiment is 95 Hz. It is explanatory drawing which shows the other example of the electric power generated when the vibration frequency by the vibration electric power generating apparatus of 1st Embodiment is 95 Hz. It is explanatory drawing which shows the other example of the change of the magnetic flux which cross | intersects the coil of the vibration electric power generating apparatus of 1st Embodiment. It is explanatory drawing which shows the other example of the change of the electromotive force which generate | occur | produces in the coil of the vibration electric power generating apparatus of 1st Embodiment, and generated electric power. It is explanatory drawing which shows an example of the electric power generated when the vibration frequency by the vibration electric power generating apparatus of 1st Embodiment is 100 Hz. It is a perspective view which shows the 1st Example of the principal part of the structure of the vibration electric power generating apparatus of 2nd Embodiment. It is explanatory drawing which shows an example of the electric power generated by the vibration electric power generating apparatus of 2nd Embodiment. It is a perspective view which shows the 2nd Example of the principal part of the structure of the vibration electric power generating apparatus of 2nd Embodiment. It is a top view which shows an example of the principal part of the structure of the vibration electric power generating apparatus of 3rd Embodiment.

(First embodiment)
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a block diagram illustrating an example of a configuration of a sensor device 200 as an electronic apparatus according to the first embodiment. The sensor device 200 (also referred to as a wireless sensor or a network sensor) includes a vibration power generation device 50 that is a power generation mechanism of the device, a rectifier circuit 61, a step-up / down circuit 62, a control unit 63, a sensor unit 64, a communication unit 65, and the like. The vibration power generator 50 includes a magnet 10, one or a plurality of coils 20.

  The sensor device 200 (that is, the vibration power generation device 50) can be attached to a predetermined vibration source that generates vibration such as an automobile, an electric product, an electronic device, and a structure (for example, a bridge). It can also be installed near the vibration source. The vibration power generator 50 can generate power by causing the magnet 10 to vibrate according to the vibration of the vibration source and generating an electromotive force in the coil 20 by electromagnetic induction based on a change in magnetic flux caused by the vibration of the magnet 10. The vibration frequency of the vibration source in the environment is, for example, about 120 Hz for a washing / drying machine or a microwave oven, about 75 Hz for a notebook personal computer, and 200 Hz around an automobile engine. The details of the vibration power generator 50 will be described later.

  The rectifier circuit 61 rectifies the alternating voltage output from the vibration power generator 50 and converts it into direct current, and outputs the converted direct current to the step-up / down circuit 62.

  The step-up / step-down circuit 62 uses the direct current output from the rectifier circuit 61 as a power source for operating itself. The step-up / step-down circuit 62 boosts or steps down the rectified direct current to a required voltage and outputs it to the control unit 63, the sensor unit 64, and the communication unit 65.

  The control unit 63 includes a microprocessor, an input / output interface, and the like, and controls the entire sensor device 200.

  The sensor unit 64 includes at least one of various sensors depending on the application of the sensor device 200. Examples of sensors include temperature sensor, magnetic sensor, optical sensor, force / weight sensor, pressure sensor, sound / ultrasonic sensor, position / displacement / angle sensor, vibration / impact / angular velocity / gyro sensor, flow rate / flow velocity / level Includes sensors, humidity / gas / odor sensors, etc. The sensor unit 64 outputs the detected data to the control unit 63 under the control of the control unit 63.

  The communication unit 65 has a wireless communication function, and transmits data detected by the sensor unit 64 to an external device under the control of the control unit 63. Note that the wireless communication includes, for example, short-range wireless communication, Internet communication, telephone line network communication, and the like.

  FIG. 2 is a perspective view illustrating an example of a main part of the configuration of the vibration power generation apparatus 50 according to the first embodiment, and FIG. 3 is a plan view illustrating an example of a main part of the structure of the vibration power generation apparatus 50 according to the first embodiment. FIG. 4 is a side view showing an example of a main part of the configuration of the vibration power generator 50 of the first embodiment. The vibration power generation device 50 is a rectangular plate body and has a magnetization direction parallel to the plate surface (directions indicated by arrows in FIGS. 3 and 4, where S and N may be reversed), A magnet 10 that can vibrate is provided.

  The magnet 10 has one edge side 12 of the magnetization direction, another edge side 11 opposite to the one edge side, and a pair of edge sides 13 and 14 parallel to the magnetization direction. The other edge side 11 of the magnet 10 is supported by a frame body 30 as a support portion. That is, the magnet 10 has a cantilever structure in which the other edge side 11 is supported. The dimension in the magnetization direction of the magnet 10 (the length of the magnet 10) is represented by ML, and the dimension in the direction crossing the magnetization direction of the magnet 10 (the width of the magnet 10) is represented by MW.

  On one edge 12 of the magnetization direction of the magnet 10, a coil 20 is provided in which a conductor 21 is wound a plurality of times along the magnetization direction. 2 to 4, three coils 20 are arranged along the plate thickness direction of the magnet 10. For convenience, the three coils 20 are referred to as an upper coil 20, a middle coil 20, and a lower coil 20 from above. Further, the upper coil 20, the middle coil 20, and the lower coil 20 are collectively referred to as a coil 20. One edge side 12 of the magnet 10 is disposed opposite to the center of the middle coil 20.

  The coil 20 is formed by winding a conductor 21 in a rectangular shape with a core 22 having a rectangular cross section in between. The dimension of the magnetization direction of the coil 20 (the length of the coil 20) is represented by CL, the height of the coil 20 is represented by CH1, the separation between the upper coil 20 and the middle coil 20, and the middle coil 20 and the lower coil 20 The separation dimension is represented by h. The magnet 10 is disposed in the horizontal direction at a position corresponding to the center of the middle coil 20 in the height direction. Further, the gap between the one edge side 12 of the magnet 10 and the middle coil 20 is represented by g. In addition, although the separation dimension h is 2 mm and the gap g is 1 mm, it is not limited to these numerical values.

  By attaching the vibration power generation device 50 to a predetermined vibration source, the cantilevered magnet 10 can be vibrated (resonant vibration). Specifically, as shown in FIG. 4, the magnet 10 vibrates (resonant vibration) in accordance with the vibration of the vibration source, and one edge 12 of the magnet 10 is substantially parallel to the cross section of the coil 20 (reference numeral A in FIG. 4). In the direction shown).

  FIG. 5 is a cross-sectional view showing an example of the configuration of the magnet 10 of the first embodiment. The magnet 10 is formed in the order of a silicon oxide film (SiO 2) 102, a tantalum layer 103, and a thin film magnet 104 on the surface of silicon (Si) 101 as a base. The thickness of each of the silicon 101, the silicon oxide film 102, the tantalum layer 103, and the thin film magnet 104 can be, for example, 500 μm, 0.2 μm, 0.02 μm, and several tens of μm to several hundred μm, but is not limited thereto. It is not something. Further, stainless steel, metal, or metallic glass can be used for the substrate instead of silicon.

  The thin film magnet 104 can be formed by, for example, physical vapor deposition (PVD method). For example, pulsed laser ablation (PLD) can be used as a kind of PVD (Physical Vapor Deposition) method. In the PLD, a base (for example, silicon) and a target (for example, an alloy of neodymium, iron, and boron: NdFeB alloy) are set in a chamber, and the inside of the chamber is brought into a high vacuum state. Thereafter, the target is irradiated with laser light (for example, wavelength: 355 nm), emitted as ions, molecules, and atoms and deposited on the surface of the substrate.

  The target may be a rare earth metal such as an NdFeB alloy or a noble metal such as an FePt alloy (platinum / iron alloy).

  The magnet 10 formed with the thin film magnet as described above has an MH characteristic such that the saturation magnetic flux density (Mr) is, for example, 1.04 T and the coercive force (Hc) is 426 kA / m. . In addition, this numerical value is an example, Comprising: It is not limited to this. However, in order to realize a large generated power, it is desirable to use an NdFeB-based or FePt-based thin film magnet having high magnetic characteristics such as a residual magnetic flux density Br of 0.5 Tesla or higher and a coercive force Hc of 250 kA / m or higher. That is, the vibration power generation apparatus 50 according to the present embodiment has an NdFeB thin film magnet or FePt thin film magnet having a residual magnetic flux density Br of 0.5 Tesla or more and a coercive force Hc of 250 kA / m or more. Large power generation capacity can be achieved.

  Further, the magnet 10 is magnetized by a magnetizing device in a direction parallel to the plate surface as shown in FIG. For example, the other edge side 11 can be the S pole and the one edge side 12 can be the N pole.

  Specific dimensions of the magnet 10 are, for example, a length ML of the magnet 10 of 20 mm and a width MW of the magnet 10 of 10 mm. The film thickness of the magnet 10 (thickness of the thin film magnet) is 150 μm. Each numerical value is not limited to these. Note that the sintered magnet is generally thick and is thinned by polishing or the like up to about 1 mm at most, and oxidative deterioration occurs due to polishing, and magnetic characteristics are also deteriorated. According to the present embodiment, the thickness of the magnet can be reduced.

  FIG. 6 is a front view showing an example of the configuration of the coil 20 of the first embodiment, and FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. As shown in FIG. 6, the coil 20 has a conductor 21 wound in a rectangular shape. As shown in FIG. 7, the conductor 21 has a rectangular cross section, the long side dimension (the height of the conductor 21) is d, and the short side dimension (the width of the conductor 21) is w. Further, the gap between the conductors 21 is assumed to be t. The pitch of the wound conductor 21 is (w + t).

  Specific dimensions of the coil 20 and the conductor 21 are, for example, as follows. The height CH1 of the coil 20 is 6 mm, the width CW1 of the coil 20 is 20 mm, the length CL of the coil 20 is 18 mm, the width w of the conductor 21 is 0.1 mm, and the height d of the conductor 21 is 0.5 mm. . The inner diameter height CH2 of the coil 20 is 5 mm, and the inner diameter width CW2 of the coil 20 is 19 mm. Moreover, the pitch (w + t) of the wound conductor 21 is 0.12 mm. The number of turns of the conductor 21 is 150. Each numerical value is not limited to these.

  Next, the evaluation result of the vibration power generator 50 of the first embodiment will be described. FIG. 8 is an explanatory diagram illustrating an example of a change in magnetic flux that intersects the coil 20 of the vibration power generator 50 according to the first embodiment. In FIG. 8, the horizontal axis indicates time (sec), and the vertical axis indicates magnetic flux (Wb). Further, for the sake of simplicity, the data of the middle coil 20 and the lower coil 20 are shown, and the data of the upper coil 20 are omitted because they are equivalent to the data of the lower coil 20. The magnet 10 having a cantilever structure was vibrated at a frequency of 95 Hz, and the maximum displacement amount on one edge side 12 of the magnet 10 was ± 15 mm.

  As shown in FIG. 8, the magnetic flux change of the intermediate coil 20 changes from the position at which the one edge side 12 of the magnet 10 is displaced to the approximate center of the intermediate coil 20 (the point at which the amount of change in magnetic flux per unit time is maximum). The magnetic flux change becomes maximum when the displacement amount is near zero. Further, it can be seen that the magnetic flux change in the lower coil 20 changes slightly later than the magnetic flux change in the middle coil 20.

  Further, as the displacement of the one edge side 12 of the magnet 10 goes to the maximum position, the change in the magnetic flux of the lower coil 20 slightly decreases, but when the displacement of the one edge side 12 of the magnet 10 exceeds the maximum position and decreases toward zero, It can be seen that the change in the magnetic flux of the lower coil 20 increases toward the peak and then decreases.

  FIG. 9 is an explanatory diagram illustrating an example of changes in electromotive force and generated power generated in the coil 20 of the vibration power generator 50 according to the first embodiment. In the upper diagram, the horizontal axis indicates time (sec), and the vertical axis indicates electromotive force (mV). In the lower diagram, the horizontal axis represents time (sec), and the vertical axis represents power (μW). It can be seen that the electromotive force and generated power peaks at the edge 12 of the magnet 10 at the approximate center of the middle coil 20 (the point at which the amount of change in magnetic flux per unit time is maximum). 8 and 9 are examples, and changes in magnetic flux, electromotive force, and generated power are not limited to these.

  FIG. 10 is an explanatory diagram illustrating an example of generated power when the vibration frequency by the vibration power generation apparatus 50 of the first embodiment is 95 Hz. As shown in FIG. 10, the magnet 10 has a length ML of 20 mm and a width MW of 10 mm, the coil 20 has a length CL of 18 mm, a width CW1 of 20 mm, and a height CH1 of 6 mm. The number of coils is a three-stage configuration of an upper stage coil, a middle stage coil 20 and a lower stage coil 20. Further, the maximum displacement amount on one edge side 12 of the magnet 10 was ± 15 mm, and the vibration frequency was 95 Hz. Several numbers are used for the number of turns of the conductor 21 and the film thickness of the magnet 10 for comparison.

  First, when the number of turns of the conductor 21 was 150 and the film thickness of the magnet 10 was 150 μm, the effective power that could be generated was 473.6 μW (maximum power: 1955.5 μW). Thus, when the magnet 10 vibrates due to the vibration of the vibration source, the magnetic flux intersecting the coil 20 (region surrounded by the wound conductor) disposed opposite to the one edge side 12 of the magnetization direction changes, so that electromagnetic induction Thus, an electromotive force can be generated in the coil 20. And it is possible to generate electric power with higher power than before by using passive energy.

  Further, the magnet 10 has a cantilever structure that supports the one edge side 12 on which the coil 20 is disposed opposite to the other edge side 11 on the opposite side, and can vibrate in the plate thickness direction. That is, the other edge side 11 of the magnet 10 is supported by a predetermined member 30 and forms a cantilever structure. By attaching the vibration power generation device 50 to a predetermined vibration source, the cantilevered magnet 10 can be vibrated (resonant vibration). Further, the magnet 10 can be vibrated at the frequency of the vibration source (resonant vibration) by appropriately setting the dimensions of the magnet 10 and making the natural frequency equal to or close to the frequency of the vibration source. Thereby, the magnet 10 vibrates according to the frequency of the vibration source, and the one edge side 12 of the magnet 10 is displaced substantially parallel to the cross section of the coil 20 so that the magnetic flux intersecting the coil 20 can be changed.

  The conductor 21 has a rectangular cross section, and the coil 20 is wound around the conductor 21 so that the direction of the short side of the conductor 21 is the magnetization direction. The dimension of the short side of the conductor 21 is w, and the dimension of the long side is d. The resistance R of the conductor is inversely proportional to w × d. The generated power P can be increased as the resistance R of the conductor 21 decreases. By winding the conductor 21 so that the direction of the short side of the conductor 21 forms the magnetization direction, for example, the dimension of the magnetization direction of the coil 20 is smaller than when the cross section of the conductor 21 is circular or square. Even if they are equivalent, the cross-sectional area of the conductor 21 can be increased, and the resistance of the conductor 21 can be reduced. As a result, large electric power can be generated.

  As shown in FIG. 10, when the number of turns of the conductor 21 is 150 and the film thickness of the magnet 10 is changed from 150 μm to 100 μm and 200 μm, the effective power that can be generated is 182.5 μW (maximum power). : 853.0 μW) and 834.0 μW (maximum power: 3471.1 μW). As described above, by increasing the thickness of the magnet 10, it is possible to generate a larger amount of electric power.

  In addition, as shown in FIG. 10, when the film thickness of the magnet 10 is 150 μm and the number of turns of the conductor 21 is changed from 150 times to 75 times, 300 times, 600 times, and 1000 times, the effective power that can be generated. Are 270.3 μW (maximum power: 983.1 μW), 915.3 μW (maximum power: 3860.9 μW), 1780.0 μW (maximum power: 76222.2 μW), and 2853.9 μW (maximum power: 12265.8 μW), respectively. there were. As described above, by increasing the number of turns of the conductor 21, it is possible to generate a larger amount of power, and it is possible to realize a power generation of about mW far exceeding about 50 μW.

  FIG. 11 is an explanatory diagram showing another example of generated power when the vibration frequency by the vibration power generator 50 of the first embodiment is 95 Hz. In the example of FIG. 11, the height CH1 of the coil 20 and the number of coils are changed as a comparative example. First, when the coil height CH1 was 6 mm and the number of coils was changed from 3 to 1 (that is, when the upper coil 20 and the lower coil 20 were removed and only the middle coil 20 was used), power could be generated. The effective power was changed from 473.6 μW (maximum power: 1955.5 μW) to 147.1 μW (maximum power: 740.8 μW).

  That is, by arranging a plurality (for example, three) of the coils 20 along the plate thickness direction of the magnet 10, the electric power that can be generated can be increased. Note that, depending on the application of the sensor device 200, if sufficient generated power can be obtained even with one coil 20, the entire device can be downsized.

  Next, when the height CH1 of the coil 20 is changed from 6 mm to 18 mm with the number of coils being one, the effective power that can be generated is 147.1 μW (maximum power: 740.8 μW) to 43. It was 8 μW (maximum power: 140.9 μW). This is probably because the cross-sectional area of the coil 20 has increased, and the crossing magnetic flux has decreased. From this, it can be seen that the width CW1 of the coil 20 is preferably not too large compared to the width MW of the magnet 10. Further, it can be seen that the height CH1 of the coil 20 is preferably not too large compared to the maximum displacement of the magnet 10.

  Further, as shown in FIG. 11, the height CH1 of the coil 20 is set to 6 mm to 3 mm, the number of coils is set to 5 (5-level stack), and the separation dimension h between the coils 20 is set to 2 mm to 1 mm. In this case, the effective power that could be generated was 473.6 μW (maximum power: 1955.5 μW) to 896.5 μW (maximum power: 3234.9 μW). Also from this, the electric power which can generate electric power can be increased by increasing the number which arrange | positions the coil 20 along the plate | board thickness direction of the magnet 10. FIG.

  FIG. 12 is an explanatory diagram illustrating another example of a change in magnetic flux that intersects the coil 20 of the vibration power generator 50 according to the first embodiment. In FIG. 12, the horizontal axis indicates time (sec), and the vertical axis indicates magnetic flux (Wb). The data of the upper stage coil 20, the middle stage coil 20, and the lower stage coil 20 are shown. The magnet 10 having a cantilever structure was vibrated at a frequency of 100 Hz, and the maximum displacement amount on one edge side 12 of the magnet 10 was ± 15 mm.

  As shown in FIG. 12, the magnetic flux change of the middle coil 20 changes from the position where the one edge 12 of the magnet 10 is displaced to the approximate center of the middle coil 20 (the point at which the amount of change in magnetic flux per unit time is maximum). The magnetic flux change becomes maximum when the displacement amount is near zero. Further, it can be seen that the magnetic flux change of the lower coil 20 changes slightly later than the magnetic flux change of the middle coil 20, and the magnetic flux change of the upper coil 20 changes slightly earlier than the magnetic flux change of the middle coil 20.

  Further, as the displacement of the one edge side 12 of the magnet 10 goes to the maximum position, the magnetic flux change of the upper coil 20 or the lower coil 20 slightly decreases, but the displacement of the one edge side 12 of the magnet 10 exceeds the maximum position and goes to zero. It can be seen that the magnetic flux change of the upper coil 20 or the lower coil 20 increases toward the peak and then decreases.

  FIG. 13 is an explanatory diagram illustrating another example of an electromotive force generated in the coil 20 of the vibration power generator 50 of the first embodiment and a change in the generated power. In the upper diagram, the horizontal axis indicates time (sec), and the vertical axis indicates electromotive force (mV). In the lower diagram, the horizontal axis represents time (sec), and the vertical axis represents power (μW). It can be seen that the electromotive force and generated power peak at approximately the center of the middle stage coil 20 (the point at which the amount of change in magnetic flux per unit time is maximum) at one edge 12 of the magnet 10. Note that FIG. 12 and FIG. 13 are examples, and changes in magnetic flux, electromotive force, and generated power are not limited to these.

  FIG. 14 is an explanatory diagram illustrating an example of generated power when the vibration frequency by the vibration power generation apparatus 50 of the first embodiment is 100 Hz. As shown in FIG. 14, the length ML of the magnet 10 is 20 mm, the width MW is 10 mm, the length CL of the coil 20 is 18 mm, the width CW1 is 20 mm, the height CH1 is 6 mm, and the number of coils is the upper stage coil and the middle stage coil. When the number of turns of the conductor 21 was 150 and the film thickness of the magnet 10 was 150 μm, the effective power that could be generated was 593.9 μW.

  Next, assuming that the number of coils is 1, the effective power that can be generated when only the upper coil 20 is used, when only the middle coil 20 is used, and when the lower coil 20 is used is 76.0 μW, 159.4 μW, and 74, respectively. 0.0 μW. In the case of only the upper stage coil 20, the case of only the middle stage coil 20, and the case of the lower stage coil 20, the total effective power is 309.4 μW, which is significantly smaller than 593.9 μW in the case of the three-stage configuration. In other words, it is possible to obtain a generated power larger than a simple sum of the power generated by the individual coils 20 by arranging a plurality of the coils 20 close to each other rather than arranging the individual coils 20 alone. Can do. This is presumably because the coils 20 are arranged close to each other so that the coils 20 interfere with each other.

  Further, as shown in FIG. 14, when the width CW1 of the coil 20 was changed from 20 mm to 10 mm, the effective power that could be generated was 593.9 μW to 827.8 μW. This is considered to be because the increase rate of the magnetic flux density contributes more than the decrease rate of the magnetic flux crossing the coil 20 by making the width CW1 of the coil 20 equal to the width MW of the magnet 10. .

  That is, the length dimension (width MW of the magnet 10) of the magnet 10 on which the coil 20 is opposed is equal to the dimension (width CW1 or inner diameter width CW2 of the coil 20) of the wound conductor 21 in the edge direction. Almost equal. Here, substantially equal, for example, when the width MW of the magnet 10 is equal to either the width CW1 or the inner diameter width CW2 of the coil 20, the width MW is smaller than the inner diameter width CW2, and the dimensional difference is, for example, the inner diameter width CW2. Including the case of about 20%. The width MW of the magnet 10 may be slightly larger than the width CW1 of the coil 20 (for example, about 20% of the width CW1). As a result, most of the magnetic flux of the magnet 10 intersects the coil 20, and the magnetic flux density of the magnetic flux intersecting the coil 20 can be increased, so that a large amount of electric power can be generated.

(Second Embodiment)
FIG. 15 is a perspective view showing a first example of a main part of the configuration of the vibration power generator 50 of the second embodiment. As shown in FIG. 15, the vibration power generation device 50 includes a shaft body 15 in a direction intersecting with the magnetization direction in the middle of the pair of edge sides 13 and 14 parallel to the magnetization direction of the magnet 10. The magnet 10 can vibrate about the shaft body 15 (can vibrate in the direction indicated by reference sign B and the direction indicated by reference sign C in FIG. 15). The cross-sectional shape of the shaft body 15 can be, for example, a triangle, and can be torsionally vibrated using a repulsive force caused by the shaft body 15 being twisted.

  Further, in the example of FIG. 15, one coil 20 (corresponding to the middle stage coil 20 of the first embodiment) is disposed to face the one edge side 12 of the magnet 10. Further, in the example of FIG. 15, the vertex of the triangle that is the cross-sectional shape of the shaft body 15 faces upward, but is not limited thereto, and the cross-sectional shape of the shaft body 15 is an inverted triangle, that is, a triangular shape. The apex may be directed downward.

  The magnet 10 can be vibrated by attaching the vibration power generation device 50 to a predetermined vibration source. Thereby, the magnet 10 vibrates according to the frequency of the vibration source, and the one edge side 12 of the magnet 10 is displaced substantially parallel to the cross section of the coil 20 so that the magnetic flux intersecting the coil 20 can be changed.

  FIG. 16 is an explanatory diagram illustrating an example of power generated by the vibration power generator 50 according to the second embodiment. As shown in FIG. 16, the length ML of the magnet 10 is 10 mm, the width MW is 20 mm, the length CL of the coil 20 is 18 mm, the width CW1 is 20 mm, and the height CH1 is 3 mm. Further, the number of turns of the conductor 21 is 150, and the thickness of the magnet 10 is 150 μm. In this case, the vibration frequency is 95 Hz, and the displacement angle (rotation angle: for example, the direction of the sign B is a positive rotation angle and the direction of the sign C is a negative rotation angle) is ± 26.6 °. , ± 36.9 °, ± 45.0 °, the effective power that could be generated was 39.0 μW (maximum power: 89.6 μW), 81.5 μW (maximum power: 209.6 μW), It was 118.9 μW (maximum power: 331.3 μW). For this reason, if the displacement angle (rotation angle) of the magnet 10 is increased, larger electric power can be generated.

  Further, as shown in FIG. 16, when the vibration frequency is changed from 95 Hz to 300 Hz, the effective power can be generated when the displacement angle of the magnet 10 is ± 20.0 ° and ± 40.0 °, respectively. The powers were 178.2 μW (maximum power: 396.6 μW) and 952.9 μW (maximum power: 2493.1 μW), respectively. From this, when the vibration frequency of the magnet 10 is increased, that is, as the vibration frequency of the vibration source is increased, larger electric power can be generated.

  As shown in FIG. 16, when the length ML of the magnet 10 is changed from 10 mm to 20 mm and the width MW is changed from 20 mm to 10 mm, the vibration frequency is 95 Hz, and the displacement angle of the magnet 10 is ± 26. When the angles were 6 ° and ± 36.9 °, the effective powers that could be generated were 36.5 μW and 61.3 μW, respectively. Also from this, the length of the edge of the magnet 10 on which the coil 20 is opposed (width MW of the magnet 10) is the dimension of the wound conductor 21 in the direction of the edge (the width CW1 of the coil 20 or the inner diameter width). By making it substantially equal to CW2), most of the magnetic flux of the magnet 10 intersects with the coil 20, and the magnetic flux density of the magnetic flux intersecting with the coil 20 can be increased, so that large electric power can be generated.

  In the example of FIG. 15, the coils 20 may be arranged close to each other along the plate thickness direction of the magnet 10 instead of one, for example, three, five, and seven. Further, in the example of FIG. 15, the coil 20 is disposed to face the one edge side 12 of the magnet 10, but the coil 20 may be disposed to face the other edge side 11 of the magnet 10. In this case, each of the one edge side 12 and the other edge side 11 of the magnet 10 can be displaced substantially parallel to the cross section of the coil 20, and more electric power can be generated.

  FIG. 17 is a perspective view showing a second example of the main part of the configuration of the vibration power generator 50 of the second embodiment. As shown in FIG. 17, rod-like weights 16 are provided along the one edge side 12 and the other edge side 11 of the magnet 10. Thereby, the moment when the magnet 10 vibrates around the shaft body 15 can be increased, a larger displacement angle (rotation angle) can be obtained, and the generated power can be increased. Further, in the example of FIG. 17, the vertex of the triangle that is the cross-sectional shape of the shaft body 15 faces upward, but is not limited to this, and the cross-sectional shape of the shaft body 15 is an inverted triangle, that is, a triangular shape. The apex may be directed downward.

(Third embodiment)
FIG. 18 is a plan view showing an example of a main part of the configuration of the vibration power generator 50 of the third embodiment. As shown in FIG. 18, an elastic member 31 is provided on each of the one edge side 12 and the other edge side 11 of the magnet 10, and each elastic member 31 is supported by a frame body 30. The magnet 10 has a double-supported beam structure. That is, the one edge side 12 and the other edge side 11 of the magnet 10 and the support portion 30 are connected by, for example, the elastic member 31 having a relatively small spring constant. The magnet 10 has a double-supported beam structure in which the one edge side 12 and the other edge side 11 are supported by the frame body 30 via the elastic member 31, and can vibrate perpendicular to the magnetization direction.

  Thereby, the magnet 10 can be vibrated perpendicularly to the magnetization direction. The magnet 10 can be vibrated by attaching the vibration power generation device 50 to a predetermined vibration source. As a result, the magnet 10 vibrates according to the frequency of the vibration source, and each of the one edge side 12 and the other edge side 11 of the magnet 10 is displaced substantially parallel to the cross section of the coil 20 to change the magnetic flux crossing the coil 20. be able to.

  According to the above-described embodiments, the electronic device such as the sensor device 200 includes the vibration power generation device 50, and thus the power generation mechanism that enables the electronic device itself to generate higher power than before using passive energy. Can be provided. That is, since the sensor device 200 itself has a power generation mechanism, it is not necessary to replace or charge the battery, which can contribute to a significant expansion of the sensor network. In addition, if battery replacement is not necessary, waste is greatly reduced, which can contribute to a significant reduction in environmental burden.

  In addition, according to each of the above-described embodiments, the vibration power generation apparatus 50 generates electric power (for example, electric power of 250 μW or more that is about four times or more) far exceeding conventional electric power generation capacity (for example, about 50 μW). Can do. That is, the vibration power generation apparatus 50 of the present embodiment achieves a power generation capacity with an effective power of 200 μW or more by appropriately setting the dimensions of the magnet, the dimensions of the coil, the number of coils, the number of turns of the coil, the film thickness of the magnet, and the like. It becomes possible to do. In addition, the vibration power generation apparatus 50 according to the present embodiment can have an approximate outer size of, for example, about 15 mm × 35 mm × 10 mm, and can be downsized. In addition, what is necessary is just to increase the number of the coils 20 suitably, when it is necessary to generate | occur | produce a big electric power according to the use of the vibration electric power generating apparatus 50. In addition, the shape of the magnet 20 and the configuration of the support are appropriately changed so that the magnet 10 vibrates in resonance with the vibration frequency of the vibration source, so that the natural frequency of the vibration power generator 50 (magnet 10) is the vibration frequency of the vibration source. You may make it approach.

  It should be noted that at least a part of the above-described embodiments can be arbitrarily combined.

DESCRIPTION OF SYMBOLS 10 Magnet 11 Other edge side 12 One edge side 13, 14 Edge side 15 Shaft body 16 Weight 20 Coil 21 Conductor 30 Frame body 31 Elastic member 50 Vibration power generator 61 Rectifier circuit 62 Buck-boost circuit 63 Control part 64 Sensor part 65 Communication part 101 Silicon 102 Silicon oxide film 103 Tantalum layer 104 Thin film magnet 200 Sensor device

Claims (10)

A rectangular plate having a magnetization direction parallel to the plate surface and capable of vibrating;
A coil that is arranged opposite to one edge side of the magnetizing direction of the magnet and has a plurality of windings arranged on the outer periphery of a core having a rectangular cross section along a direction parallel to the magnetizing direction,
The conductor has a rectangular cross section,
The short side surface of the conductor is opposed to the outer periphery of the core,
An oscillating power generator that generates electromotive force in the coil by electromagnetic induction. A support portion for supporting the other edge side opposite to the one edge side of the magnet;
The magnet
The vibration power generation device according to claim 1, wherein the vibration power generation device has a cantilever structure. A shaft in a direction crossing the magnetization direction is provided in a midway part of a pair of edges parallel to the magnetization direction of the magnet,
The magnet
The vibration power generator according to claim 1, wherein the vibration power generator is configured to be able to vibrate about the shaft body. An elastic member provided on each of the one edge side of the magnet and the other edge side opposite to the one edge side;
A support portion for supporting each elastic member,
The magnet
The vibration power generation apparatus according to claim 1, wherein the vibration power generation apparatus has a double-supported beam structure.   5. The vibration power generation apparatus according to claim 1, wherein the coil is further arranged to face the other edge side opposite to the one edge side of the magnet. 6.   The vibration power generator according to any one of claims 1 to 5, wherein a plurality of the coils are arranged along a plate thickness direction. The coil is formed by winding the conductor into a rectangular shape,
Length of edge of the coil is disposed opposite the magnets, to any one of claims 1 to 6, characterized in that substantially equal to said edge side direction of the dimension of the wound conductor The vibration power generator described. The magnet
A substrate;
The vibration power generator according to any one of claims 1 to 7 , further comprising: a thin film magnet formed by physical vapor deposition on a surface of the substrate. An electronic apparatus comprising the vibration power generation device according to any one of claims 1 to 8 . A rectangular plate having a magnetization direction parallel to the plate surface and vibrating a magnet that can vibrate;
A coil that is arranged opposite to one edge side of the magnetizing direction of the magnet and is wound by arranging a plurality of conductors on the outer periphery of a core having a rectangular cross section along a direction parallel to the magnetizing direction. vibration power method but a rectangular shape, characterized in that it comprises the steps of generating an electromotive force by electromagnetic induction the surface of the short sides of the conductor to the coil is opposed to the outer periphery of the core.

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