Vibration power generation module and vibration power generation device

Abstract

This vibration power generation module (60) is provided with: a magnet unit (24) that is attached to a vibrating body (32) via a spring (21), and that is provided with a permanent magnet in which the spring constant of the spring (21) and the weight thereof are determined so as to resonate with the spring (21) in a swinging motion shape with the vibration of the vibrating body (32); and a power generation element (10) that generates a voltage due to electromagnetic induction and a large Barkhausen effect on a coil wound around the magnetic body core due to a change in a magnetic field based on the relative displacement of the position with the magnet unit (24) that resonates.

Description

Vibration power generation module and vibration power generation device

[0001] The present disclosure relates to a vibration power generation module and a vibration power generation device.

[0002] When a magnetic material is magnetized under tension or with residual internal stress, the magnetic domain walls inside the magnetic material move all at once, causing the magnetization direction to reverse in an extremely short time. This is known as the large Barkhausen effect. When a pickup coil is wound around a magnetic material that exhibits the large Barkhausen effect, a pulse voltage can be generated in the pickup coil in response to the reversal of the magnetization direction of the magnetic material.

[0003] Based on the large Barkhausen effect, energy harvesting technology is known, which uses human activity (for example, walking) or machine vibrations as energy available in the environment to generate electricity.

[0004] Patent Document 1 discloses a power generating element in which a magnetic field is changed by the reciprocating motion caused by the vibration of a magnet attached to a spring, causing magnetization reversal in a magnetic wire due to the large Barkhausen effect, and the resulting pulse voltage generated in a pickup coil wound around the magnetic wire charges a capacitor.

[0005] International Publication No. 2018 / 097110

[0006] However, the technology described in Patent Document 1 only guides a portion of the magnetic field lines generated from the magnet to the magnetic core, which has the problem that the efficiency of guiding the magnetic field lines generated from the magnet to the magnetic core is not good.

[0007] The present disclosure aims to provide a vibration power generation module and a vibration power generation device that can increase the amount of power generation by improving the efficiency of inducing magnetic field lines generated from a magnet to a magnetic core.

[0008] The vibration power generation module of the present disclosure comprises a magnet part attached to a vibrating body via a spring and equipped with a permanent magnet, and a power generation element in which a voltage is generated in a coil wound around a magnetic core due to a change in the magnetic field based on a relative displacement of the position of the resonating magnet part, and is characterized in that the spring constant of the spring and the weight of the magnet part are determined so that both the spring and the magnet part resonate due to the vibration of the vibrating body.

[0009] The vibration-powered energy harvester of the present disclosure is characterized by comprising: a rectifier that rectifies a voltage output by the power generation element of the power generation module according to any one of claims 1 to 9; and a storage unit that stores the voltage rectified by the rectifier.

[0010] According to the present disclosure, it is possible to provide a vibration power generation module and a vibration power generation device that can increase the amount of power generation by improving the efficiency of inducing magnetic lines of force generated from a magnet to a magnetic core.

[0011] 3A is a perspective view showing the configuration of a power generation element used in the vibration power generation module and vibration power generation device according to Embodiments 1 and 2, and FIG. 3B is a side view thereof. (a) is a perspective view showing a schematic configuration of a power generation element different from the power generation element shown in FIG. 1 , and FIG. 3B is a side view thereof. (a) is an explanatory diagram of the flow of magnetic field lines in the power generation element, and (b) is an explanatory diagram of the flow of magnetic field lines when the magnetization direction of the magnet portion is opposite to that of FIG. 3A. (b) is a perspective view showing an example of the configuration of a vibration power generation device according to Embodiment 1. (c) is an explanatory diagram showing the magnetic flux density waveform in the magnet thickness direction. (d) is an explanatory diagram showing the positional relationship between the displacement directions of the first magnet and the second magnet and the magnetic flux collector of the power generation element. (a) is a schematic diagram showing an example of a voltage waveform generated by electromagnetic induction in a coil wound around an iron core not having the large Barkhausen effect, and a voltage waveform due only to the large Barkhausen effect. (b) is a schematic diagram showing an example of a voltage waveform generated in the coil due to electromagnetic induction and the large Barkhausen effect according to this embodiment. Fig. 1 is a block diagram showing an example of the configuration of a vibration power generation device according to embodiment 1. Fig. 2 is a perspective view showing an example of the configuration of a vibration power generation module according to embodiment 2. Fig. 3 is a perspective view showing an example of the configuration of a vibration power generation module according to a modified example of embodiment 2. Fig. 4 is a schematic diagram of a power generation module according to embodiment 3. Fig. 5 is a schematic diagram of a modified example of the power generation module according to embodiment 3. Fig. 6 is a schematic diagram of a power generation module according to embodiment 4.

[0012] Below, a vibration power generation module and a vibration power generation device according to embodiments 1 and 2 will be described with reference to the drawings. The following embodiments are merely examples, and the embodiments can be combined as appropriate and each embodiment can be modified as appropriate.

[0013] FIG. 1 is a perspective view showing the configuration of a power generating element 10 used in the vibration power generating module and vibration power generator according to the first and second embodiments, and FIG. 1( b ) is a side view thereof. The power generating element 10 according to this embodiment has one or more composite magnetic wires that form a magnetic core 11 that generates a large Barkhausen effect. The power generating element 10 preferably has a magnetic collector (soft magnetic material) 13 surrounding the outer periphery of the magnetic core 11. The magnetic collectors 13 are disposed at both ends of the magnetic core 11 as a first magnetic collector 13A and a second magnetic collector 13B, respectively, and a coil 12 is wound around the magnetic core 11. The soft magnetic material used for the magnetic collector 13 is preferably a steel material such as SS400 or S45C, a magnetic stainless steel material such as SUS430 or SUS440, or a high-permeability material such as permalloy or permendur, but any material with a magnetic permeability equal to or greater than that of air (a material with a relative magnetic permeability greater than 1) will do. The magnetic core 11 has a magnetostrictive effect, and expands and contracts due to magnetostriction in response to changes in the applied magnetic field.

[0014] FIG. 2( a) is a perspective view schematically illustrating the configuration of a power generating element 70 that is different from the power generating element 10 shown in FIG. 1, and FIG. 2( b) is a side view thereof. The power generating element 70 shown in FIG. 2 has a bobbin shape. In this case, the power generating element 70 is also called a magnetic bobbin. The coil 12 is wound around a cylindrical magnetic member 131, which is the narrowed portion of the magnetic bobbin. Note that the power generating element 70 can also be made only from a soft magnetic material such as iron as shown in FIG. 2, but power generation efficiency is improved by including a magnetic core 11 that generates the large Barkhausen effect as shown in FIG. 1.

[0015] The flow of magnetic field lines 84 in the power generating element 10 shown in FIG. 1 will be described using FIG. 3( a). FIG. 3 is a diagram illustrating the flow of magnetic field lines in the power generating element 10, showing the power generating element 10 and the magnet section 24 from a side view. FIG. 3( a) is an explanatory diagram of the flow of magnetic field lines in the power generating element. FIG. 3( b) is an explanatory diagram of the flow of magnetic field lines when the magnetization direction of the magnet section is opposite to that of FIG. 3( a). In FIG. 3( a), magnetic field lines 84 emerging from the magnetized surface 80 (north pole) of the magnet section 24 along the magnetization direction 82 enter the first magnetic collector 13A, pass through the magnetic core 11, and exit into the air from the second magnetic collector 13B. That is, the magnetic field lines 84 passing through the first magnetic collector 13A and the second magnetic collector 13B both point in the +Y direction. Note that some of the magnetic field lines 84 enter the magnetic core 11 directly.

[0016] Next, the flow of magnetic field lines 94 in the power generating element 10 in which the magnetization direction 92 of the magnet portion 24 is opposite to that shown in FIG. 3( a) will be described with reference to FIG. 3( b). In FIG. 3( b), the first magnetic collector 13A faces the magnetized surface 90 (south pole) of the magnet portion 24, which is the opposite of the case shown in FIG. 3( a). Therefore, the magnetic field lines 94 pass from the second magnetic collector 13B through the magnetic core 11 and then through the first magnetic collector 13A toward the magnetized surface 90 (south pole). In other words, the magnetic field lines 94 passing through the first magnetic collector 13A and the second magnetic collector 13B are both oriented in the −Y direction. Note that some of the magnetic field lines 84 enter the magnetic core 11 directly. As shown in Figures 3(a) and 3(b), the magnetized surfaces 80, 90 of the magnet section 24 and the magnetic field collector 13 of the power generating element 10 face each other, and the magnetic field collector surfaces 13A, 13B are perpendicular to the longitudinal direction of the power generating element 10 (the direction of the magnetic field lines 84, 94 that contribute to power generation in the coil). As a result, the magnetic field lines 84, 94 emerging from the magnetized surfaces 80, 90 of the magnet section 24 enter the magnetic field collector 13 straight, travel almost straight through the magnetic core 11 in the power generating element 10, and emerge from the magnetic field collector 13 on the opposite side. This results in very little loss of the magnetic field lines 84, 94 emerging from the magnet section 24, making it possible to obtain the most efficient electromagnetic induction power generation.

[0017] First Embodiment Fig. 4 is a perspective view showing an example of the configuration of a vibration power generation module 60 according to the first embodiment. The vibration power generation module 60 shown in Fig. 4 includes a magnet section 24 attached via a spring 21 to a vibrating body 32, such as a machine, serving as a base, and a power generation element 10 attached to the vibrating body 32 via a base 15. The magnet section 24 is composed of a first magnet 25, a second magnet 26, and a weight 27. The weight 27 is installed on the opposite side of the power generation element 10 with respect to the central axis of vibration of the spring 21. The power generation element 10 is composed of a magnetic core 11, a magnetic collector 13, and a coil 12. The spring 21 may be a coil spring or any other spring in general, such as a leaf spring, and may include any mechanism capable of amplifying vibration through resonance, similar to a spring.

[0018] The spring constant of spring 21 and the weight of magnet section 24 are designed to resonate together with spring 21 with the vibration frequency of vibrating body 32, and the spring 21 amplifies the minute vibrations of vibrating body 32. The amount of displacement caused in magnet section 24 by amplification becomes larger than the amount of displacement caused in power generating element 10, causing a relative displacement between magnet section 24 and power generating element 10, and this relative displacement generates a voltage in coil 12 of power generating element 10. Furthermore, because weight 27 positions the center of gravity of magnet section 24 closer to weight 27 than the central axis of vibration of spring 21, magnet section 24 can vibrate in an oscillating motion rather than simple harmonic motion. This oscillating motion can amplify the amount of positional displacement of each of first magnet 25 and second magnet 26 constituting magnet section 24 relative to power generating element 10 more than in the case of simple harmonic motion.

[0019] 4 , the magnet section 24 is provided with a first magnet 25 and a second magnet 26, which are permanent magnets, so as to face the respective magnetic flux collectors 13 provided at both ends of the power generating element 10. The first magnet 25 and the second magnet 26 have approximately the same magnetic force as indicated by magnetic moments 25M and 26M, and the magnetized surfaces of the first magnet 25 and the second magnet 26 that do not face the magnetic flux collector 13 are attached via a magnetic yoke 29 so that the polarities (directions of magnetization) of the first magnet 25 and the second magnet 26 are opposite to each other with respect to the power generating element 10. In other words, the first magnet 25 and the second magnet 26 are magnetized so that the magnetic poles of the first magnet 25 and the second magnet 26 are opposite to each other and the magnetic lines of force generated from each of the first magnet 25 and the second magnet 26 pass through the power generating element 10 along the magnetic core 11. The magnetized surfaces of the first magnet 25 and the second magnet 26 that do not face the power generating element 10 are fixed to a magnetic yoke 29 so that the magnetized surfaces of the first magnet 25 and the second magnet 26 are aligned in the direction of relative displacement. The magnetic yoke 29 is made of a soft magnetic material such as iron. In the first embodiment, the magnetic yoke 29 to which the first magnet 25 and the second magnet 26 are fixed is magnetized by the magnetic force of the first magnet 25 and the second magnet 26, thereby increasing the magnetic force acting on the power generating element 10. The magnetic yoke 29 may be integral with the weight 27.

[0020] Fig. 6 is an explanatory diagram showing the positional relationship between the displacement direction 50 of the first magnet 25 and the second magnet 26 and the magnetic flux collector 13 of the power generating element 10. The displacement direction 50 shown in Fig. 6 is the amount of change in the relative position of the resonating magnet section 24 with respect to the power generating element 10. As shown in Figs. 4 and 6, the magnetized surfaces of the first magnet 25 and the second magnet 26 face the magnetic flux collector 13 with a gap 31 between them. The narrower the gap 31, which is the distance between the magnetized surfaces of the first magnet 25 and the second magnet 26 and the magnetic flux collector 13, the greater the magnetic force acting on the magnetic core 11, and the greater the amount of power generated. Fig. 5 is a schematic diagram showing an example of the magnetic flux density waveform of the magnet section 24 when the gap 31 is 0.5 mm, 1 mm, and 2 mm. 5 , among the conditions where gap 31 is 0.5 mm, 1 mm, and 2 mm, the magnetic flux density is maximum when gap 31 is 0.5 mm, but because a magnetic attraction force acts between first magnet 25 and second magnet 26 and magnetic flux collector 13, the minimum gap 31 that can actually be assembled is about 1 mm. In the first embodiment, magnet section 24 performs an oscillating motion, and therefore gap 31 is set so that oscillating magnet section 24 does not interfere with magnetic flux collector 13 of power generating element 10.

[0021] 5 shows that the magnetic flux density waveform in the magnet thickness direction, i.e., the direction of magnetic moment 25M or magnetic moment 26M, has two peaks on the positive side of the magnetic flux density. When gap 31 is 1 mm, the peak spacing is approximately 6 mm, so the most efficient width of magnetic collector 13 is 6 mm. In order to obtain even more magnetic force when gap 31 is 1 mm, for example, by installing magnetic collector 13 with a width of approximately 8 mm, it becomes possible to collect even more magnetic lines of force 52 in magnetic core 11, and theoretically, approximately 90% of the magnetic flux of magnet portion 24 can be induced to magnetic core 11.

[0022] The width of the magnetic flux collector 13 in the power generating element 10 in the direction of relative displacement of its position with respect to the magnet section 24 (the vertical direction in FIG. 4 ) is approximately 60% of the width of the magnetized surfaces of the first magnet 25 and the second magnet 26 of the magnet section 24 facing the magnetic flux collector 13 in the direction of relative displacement, with an upper limit of 80%. The magnet section 24 requires at least two magnets, the first magnet 25 and the second magnet 26, and the narrower the installation interval between the first magnet 25 and the second magnet 26, the smaller the amount of magnet displacement required to generate power. If the width of the magnetic flux collector 13 in the direction of relative displacement is wide, the gap 28 between the first magnet 25 and the second magnet 26 must be wide, and therefore exceeding the most efficient width (6 mm) described above is disadvantageous in terms of magnet spacing. Therefore, from the perspective of the balance between magnetic force and magnet spacing, the width of the magnetic flux collector is preferably 60% of the width of the magnets, with an upper limit of 80%.

[0023] The gap 28 provided between the first magnet 25 and the second magnet 26 is made of a non-magnetic material, and the width of the gap 28 in the direction of relative displacement is desirably equal to or greater than the width of the magnetic collector 13 in the direction of relative displacement. The gap 28 may be an air gap, or may be filled with a non-magnetic material such as copper, aluminum, or synthetic resin. If the width of the magnetic collector 13 in the direction of relative displacement is wide, when the magnetic collector 13 straddles the first magnet 25 and the second magnet 26 due to relative displacement, the magnetic collector 13 will collect both the upward magnetic field lines 52 of the first magnet 25 and the downward magnetic field lines 52 of the second magnet 26. As a result, the upward magnetic field lines 52 and the downward magnetic field lines 52 cancel each other out within the magnetic core 11, resulting in a slower change in magnetic flux within the magnetic core 11. By providing a gap 28 between the first magnet 25 and the second magnet 26 that is approximately the same as or larger than the width of the magnetic collector 13, as shown in Figure 6, the risk of the magnetic collector 13 straddling the first magnet 25 and the second magnet 26 is reduced, and the internal magnetic flux change of the magnetic core 11 can be increased.

[0024] The magnet unit 24 includes a first magnet 25 and a second magnet 26 connected to a magnetic yoke 29, and a weight 27, which are covered by a housing 30 made of a non-magnetic material such as copper, aluminum, or synthetic resin. One end of the spring 21 is fixed to a vibrating body 32, and the other end of the spring 21 is fixed to the bottom of the housing 30.

[0025] As shown in FIGS. 4 and 6 , when the spring 21 is not vibrating, the magnetic collectors 13 at both ends of the power generating element 10 face either end of the first magnet 25 or the second magnet 26. Therefore, when the spring 21 is not vibrating, the power generating element 10 and the first magnet 25 or the second magnet 26 are arranged in series, such as the first magnet 25-power generating element 10 or the second magnet 26-power generating element 10, so that magnetic field lines 52 generated from one end of the first magnet 25 or the second magnet 26 reach the other end of the first magnet 25 or the second magnet 26 via the magnetic core 11 of the power generating element 10. As a result of the magnetic field lines 52 generated from the first magnet 25 or the second magnet 26 being efficiently induced to the magnetic core 11, a voltage due to electromagnetic induction is generated in the coil 12 in addition to a pulse voltage due to the large Barkhausen effect.

[0026] When the spring 21 vibrates due to the above-described resonance, the magnet facing the magnetic collector 13 of the power generating element 10 is switched, for example, from the first magnet 25 to the second magnet 26, thereby reversing the magnetic field applied to the magnetic core 11 of the power generating element 10. This reversal of the magnetic field causes the large Barkhausen effect, in which the magnetization direction inside the magnetic core 11 is reversed, and electromagnetic induction occurs in the coil 12, generating a pulse voltage with a waveform as shown in FIG.

[0027] In the first embodiment, the magnetic field collector 13 of the power generating element 10 faces the magnetized surface of each of the first magnet 25 and the second magnet 26, and therefore most of the magnetic field lines 52 generated from the first magnet 25 or the second magnet 26 propagate to the magnetic core 11 via the magnetic field collector 13 facing the magnetized surface. As a result, the magnetic field lines 52 can be efficiently guided to the magnetic core 11 via the magnetic field collector 13. The magnetic field lines 52 generated from the first magnet 25 or the second magnet 26 then propagate along the magnetic core 11, penetrating the power generating element 10. When the magnet section 24 moves in the displacement direction 50 due to resonance, the magnet facing the magnetic field collector 13 of the power generating element 10 is switched, for example, from the first magnet 25 to the second magnet 26, and the direction of the magnetic field lines 52 acting on the magnetic field collector 13 is reversed. As a result, a voltage is generated in the coil 12 due to the large Barkhausen effect and electromagnetic induction.

[0028] 7A is a schematic diagram showing an example of a voltage waveform 140 generated by electromagnetic induction in a coil wound around an iron core that does not have the Large Barkhausen effect, and a voltage waveform 141 due to only the Large Barkhausen effect. The voltage waveform 140 generated in the coil 12 wound around an iron core that does not have the Large Barkhausen effect in FIG. 7A has a wide pulse width and a large amount of generated charge, but a low peak voltage of about 5 V. The voltage waveform 141 due to only the Large Barkhausen effect has a high peak voltage of 15 to 20 V, but a narrow pulse width of about 80 μS or less and a small amount of charge.

[0029] 7(b) is a schematic diagram showing an example of a voltage waveform 142 generated in the coil 12 due to electromagnetic induction and the large Barkhausen effect according to the first embodiment. In the first embodiment, a high voltage of approximately 20 to 25 V can be obtained by superimposing a voltage waveform with a large amount of charge due to electromagnetic induction and a voltage waveform with a significant peak voltage due to the large Barkhausen effect. Efficient charging of a capacitor requires both a potential difference and an electric charge, and the power generation device according to the first embodiment is suitable for charging a capacitor.

[0030] Fig. 8 is a block diagram showing an example of the configuration of the vibration-powered energy harvester 100 according to the first embodiment. The vibration-powered energy harvesting module 60 includes the power generation element 10 and a magnet section 24, and generates a voltage in the coil 12 due to the displacement of the magnet section 24 relative to the power generation element 10. The voltage generated in the coil 12 exhibits a positive and negative pulse shape as shown in Fig. 7(b), and is therefore full-wave rectified by the rectifier section 62. The rectifier section 62 may perform half-wave rectification instead of full-wave rectification.

[0031] The voltage full-wave rectified by the rectifier 62 is stored in the storage unit 64. The storage unit 64 is a rechargeable secondary battery, a capacitor, or the like. The waveform of the voltage output by the power generating element 10 exhibits a pulse shape with a prominent peak due to the Barkhausen effect. Therefore, if there is a risk that the voltage will exceed the allowable voltage for storage in a secondary battery such as a lithium-ion battery, a nickel-metal hydride battery, or a nickel-cadmium battery, a capacitor is used for the storage unit 64.

[0032] The power stored in the power storage unit 64 can be used, for example, as a power source for a sensor that detects the surrounding environment. When the vibration-powered energy generator 100 is installed in a machine tool, the sensor detects the temperature, humidity, acceleration, current, magnetic field, CO ２ When the vibration-powered energy generator 100 is installed in a general environment such as a house, it can detect the temperature, humidity, wind speed, wind direction, precipitation, magnetic field, CO ２ It can be used as a power source for sensors that detect concentration, pH of water or soil, water level, soil moisture content, land slope, acceleration (impact) due to earthquakes, etc., or solar radiation (on cloudy days).

[0033] As described above, according to the vibration power generation module 60 and the vibration power generation device 100 of the first embodiment, in addition to the magnetization reversal in the magnetic core 11 due to the large Barkhausen effect, the magnetic core 11 is actively utilized as an electromagnetic induction core, and the magnetic field lines 52 generated from the magnet section 24 are guided to the magnetic core 11 via the magnetic collector 13. As a result, it is possible to increase the amount of power generation by maximizing the electromagnetic induction component in addition to the large Barkhausen effect.

[0034] In the first embodiment, the spring constant of spring 21 and the weight of magnet portion 24 are determined so as to resonate with the vibration frequency of vibrating body 32, thereby amplifying the minute vibrations of vibrating body 32 with spring 21 and increasing the displacement of the magnet. In addition, weight 27 provided on magnet portion 24 shifts the center of gravity of magnet portion 24 from the central axis of vibration, adding a swinging motion of magnet portion 24 to the up and down vibration, thereby amplifying the displacement of the magnet.

[0035] Second Embodiment Next, a vibration power generation module 72 according to the second embodiment will be described. Fig. 9 is a perspective view showing an example of the configuration of the vibration power generation module 72 according to the second embodiment. The vibration power generation module 72 shown in Fig. 9 differs from the first embodiment in that the magnet section 40 attached to the vibrating body 32, such as a machine, serving as a base via the spring 21 does not have a weight 27, and a holding mechanism 34 is provided on the vibrating body 32 side of the spring 21 to hold the spring 21 at an arbitrary position with respect to its entire length. However, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

[0036] The magnet unit 40 is substantially the same as the magnet unit 24 of the first embodiment, except that it does not include the weight 27. As in the first embodiment, the gap 42 between the first magnet 25 and the second magnet 26 is made of a non-magnetic material, and the width of the gap 42 in the direction of relative displacement is desirably equal to or greater than the width of the magnetic collector 13 in the direction of relative displacement. The gap 42 may be an air gap or may be filled with a non-magnetic material such as copper, aluminum, or synthetic resin. If the width of the magnetic collector 13 in the direction of relative displacement is wide, when the magnetic collector 13 straddles the first magnet 25 and the second magnet 26 due to relative displacement, the magnetic collector 13 will collect both the upward magnetic field lines 52 of the first magnet 25 and the downward magnetic field lines 52 of the second magnet 26. As a result, the upward magnetic field lines 52 and the downward magnetic field lines 52 cancel each other out within the magnetic core 11, resulting in a slower change in magnetic flux within the magnetic core 11. By providing a gap 42 between the first magnet 25 and the second magnet 26 that is approximately the same as or larger than the width of the magnetic collector 13, as shown in Figure 6, the risk of the magnetic collector 13 straddling the first magnet 25 and the second magnet 26 is reduced, and the internal magnetic flux change of the magnetic core 11 can be increased.

[0037] In addition, the magnet unit 24 has a first magnet 25 and a second magnet 26 connected to a magnetic yoke 41, which are covered with a housing 43 made of a non-magnetic material such as copper, aluminum, or synthetic resin. One end of the spring 21, the other end of which is fixed to the vibrating body 32, is fixed to the bottom of the housing 43.

[0038] The holding mechanisms 34 are available in different lengths in the direction of arrow 33, and by using holding mechanisms 34 with different lengths in the direction of arrow 33, the length of the vibrating part of the spring 21 (hereinafter referred to as the "spring length") can be changed. Since the vibration frequency of each vibrating body 32, which is a machine or the like, varies from device to device even if they are of the same model, adjusting the spring length with the holding mechanism 34 adjusts the spring constant to the resonant frequency of each vibrating body 32, making it possible to generate power efficiently. Furthermore, the power obtained by the vibration power generation module 72 according to the second embodiment can be supplied to the vibration power generation device 100 shown in FIG. 8.

[0039] In the second embodiment, the magnet unit 40 does not have the weight 27, but this is not limiting. The magnet unit 40 according to the second embodiment may have the weight 27, similar to the first embodiment.

[0040] Next, a vibration power generation module 74 according to a modification of the second embodiment will be described. Fig. 10 is a perspective view showing an example of the configuration of the vibration power generation module 74 according to the modification of the second embodiment. The vibration power generation module 74 shown in Fig. 10 differs from the second embodiment in that the holding mechanism 35 provided on the vibrating body 32 side of the spring 21 has a cylindrical shape, and a bolt 36 can be locked into one of a plurality of screw holes provided in the vertical direction on the side of the cylindrical shape. However, the same components as those in the second embodiment are denoted by the same reference numerals as those in the second embodiment, and detailed description thereof will be omitted.

[0041] In the second embodiment, the spring length is changed by replacing the holding mechanism 34 with one having a different length in the direction of the arrow 33, but in the modified example of the second embodiment, the spring constant of the spring 21 can be easily and quickly adjusted to the resonance frequency of each vibrating body 32 by changing the position of the bolt 36 that engages with the holding mechanism 35. The electric power obtained by the vibration power generation module 74 according to the modified example of the second embodiment can be supplied to the vibration power generation device 100 shown in FIG.

[0042] In the first embodiment, the second embodiment, and the modified example of the second embodiment, the power generating element 10 is provided with the magnetic collector 13 that efficiently guides the magnetic field lines 52 generated from the magnet portion 24, but this is not limiting. The power generating element 10 may be configured with only the magnetic core 11 and the coil 12 without the magnetic collector 13. Also, the magnetized surface of the magnet portion 24 and the magnetic collector 13 may not face each other. Furthermore, the power generating element 10 may be configured without the magnetic core 11, with the bobbin-shaped member being made of only a soft magnetic material such as iron.

[0043] Next, we will explain embodiment 3. Embodiment 3 can be configured in two ways, as shown in Figures 11 and 12, depending on the magnetization directions 430, 432 of magnet 410. Figure 11 shows a case where magnetization direction 430 of magnet 410 is the longitudinal direction, and Figure 12 shows a case where magnetization direction 432 of magnet 410 is the thickness direction of magnet 410.

[0044] The configuration in Figure 11 shows an example of a configuration in which the magnetized surface 410A of the magnet 410 and the magnetized surface 110A of the power generating element 110 do not face each other. Utilizing the property that magnetic field lines are incident perpendicularly on the surface of a magnetic material, the magnetized surfaces 110A and 110B are perpendicular to the longitudinal direction (the direction in which the magnetic field lines flow) of the magnetic core 111, and the magnetic field lines incident on the magnetized surface 110A are guided straight into the magnetic core 111. The magnetization direction of the magnet 410 is the longitudinal direction (the left-right direction in the figure), and the left side of the magnet 410 becomes the magnetized surface 410A with a north pole. The magnetic field lines 420 emerging from the magnetized surface 410A go around the periphery of the magnet 410 and enter the south pole of the magnetized surface 410B. At this time, power generating element 110 is located above magnet 410, and the magnetic field lines circling around magnet 410 are collected by magnetism collecting surface 110A and take a path that passes through magnetic core 111 from magnetism collecting surface 110B to magnetized surface 410B of magnet 410. In this case, only a portion of the magnetic field lines emanating from magnetized surface 410A are collected by magnetism collecting body 112 and guided to power generating element 110, resulting in lower electromagnetic induction efficiency compared to embodiment 1. However, if the power consumption of the power load connected to the power generating device according to embodiment 3 is significantly reduced to obtain power that allows operation even with the inefficient electromagnetic induction component, there is the advantage of a high degree of freedom in the placement of the power generating element relative to magnet 410.

[0045] 12 shows a modification of Embodiment 3 in which magnetism collecting surface 110A of power generating element 110 is configured as a side surface of magnetism collector 112, so that the magnetized surface of magnet 410 faces magnetism collecting surface 110A of power generating element 110. The magnetization direction of magnet 410 is the thickness direction (the vertical direction in the figure), with magnetism collecting surface 410A with a north pole on the upper left surface of magnet 410 and magnetism collecting surface 410B with a south pole on the upper right surface of magnet 410. Magnetic field lines 422 emitted from magnetism surface 410A are concentrated by magnetism collecting surface 110A on the side surface of magnetism collector 112, and travel a path through magnetic core 111 from magnetism collecting surface 110B to magnetized surface 410B of magnet 410.

[0046] In this case, there are two issues: Issue (1): Because the longitudinal directions of the magnetic field collecting surface 110A and the magnetic core 111 (the direction of the magnetic field lines that contribute to power generation in the coil) are parallel, the magnetic field lines entering from the magnetic field collecting surface 110A must be guided into the magnetic core 111 so as to bend at approximately 90 degrees. As a result, some of the magnetic field lines do not bend completely within the magnetic field collecting body 112, and instead travel straight and leak out into the air (shown by the dashed lines in the figure), which reduces the efficiency of electromagnetic induction. Issue (2): When multiple composite magnetic wires are bundled together in the magnetic core 111 as shown in Figure 1, the magnetic field lines of the composite magnetic wires closer to the magnet 410 tend to penetrate easily, while the magnetic field lines of the composite magnetic wires farther from the magnet 410 tend not to penetrate easily, which causes variations in the internal magnetic flux among the multiple composite magnetic wires and reduces the efficiency of electromagnetic induction.

[0047] Note that, as in embodiment 1, when magnetized surface 410A of magnet 410 and magnetization surface 110A of power generating element 110 face each other and magnetization surface 110A is perpendicular to the longitudinal direction of power generating element 110 (the direction of the magnetic field lines that contribute to power generation in the coil), the magnetic field lines emitted from magnetized surface 410A of magnet 410 enter magnetization surface 110A straight, continue straight through power generating element 110, and exit from magnetization surface 110B on the opposite side. This results in very little loss of the magnetic field lines emitted from magnet 410, and is a desirable configuration that enables the most efficient electromagnetic induction power generation.

[0048] Next, a fourth embodiment will be described. Fig. 13 is a perspective view showing a schematic configuration of a power generation module according to the fourth embodiment. In Fig. 13, a power generation element 110 uses a composite magnetic wire that generates a large Barkhausen effect as a magnetic core 111 around which a coil 120 is wound, but differs from the power generation element 10 shown in Fig. 1 in that no magnetic collector 112 is used.

[0049] In this configuration, since the magnetic collector 112 is not provided, the power generation efficiency is even lower than that of FIG. 11 or FIG. 12 ; however, if the power consumption of the power load connected to the power generation device of embodiment 4 can be made very small to obtain power that is sufficient to operate even with inefficient electromagnetic induction components, the number of components can be reduced and the power generation module can be constructed inexpensively.

[0050] 10 power generation element, 11 magnetic core, 12 coil, 13 magnetic collector, 15 base, 21 spring, 24 magnet section, 25 first magnet, 25M magnetic moment, 26 second magnet, 26M magnetic moment, 27 weight, 28 gap, 29 magnetic yoke, 30 housing, 31 gap, 32 vibrating body, 34, 35 holding mechanism, 42 gap, 43 housing, 50 displacement direction, 60 vibration power generation module, 62 rectification section, 64 power storage section, 70 power generation element, 72, 74 vibration power generation module, 100 vibration power generation device.

Claims

1. A vibration power generation module, comprising: a magnet part provided with a permanent magnet and attached to a vibrating body via a spring; and a power generation element in which a voltage is generated in a coil wound around a magnetic core due to a change in a magnetic field based on a relative displacement in position between the magnet part that resonates. The spring constant of the spring and the self-weight of the magnet part are determined such that the spring and the magnet part both resonate due to the vibration of the vibrating body.

2. The vibration power generation module according to claim 1, wherein the magnet part comprises a first magnet which is the permanent magnet, a second magnet, and a weight, and the self-weight is determined.

3. The vibration power generation module according to claim 2, wherein the first magnet and the second magnet are magnetized such that their magnetic poles are opposite to each other and the magnetic force lines generated from each of the first magnet and the second magnet penetrate the power generation element along the magnetic core, and the magnetization surfaces of each of the first magnet and the second magnet are arranged corresponding to the direction of the relative displacement and the magnetization surfaces of each of the first magnet and the second magnet that do not face the power generation element are fixed to a magnetic yoke.

4. The vibration power generation module according to claim 3, wherein the power generation element comprises flux concentrators made of a soft magnetic material at both ends in the longitudinal direction of the magnetic core, and the magnetic core and the flux concentrators are integrally formed in a bobbin shape.

5. The vibration power generation module according to claim 4, wherein the width of the flux concentrator in the direction of the relative displacement is 60% to 80% of the length of the width of the magnetization surface of the magnet part facing the flux concentrator in the direction of the relative displacement.

6. The vibration power generation module according to claim 5, wherein there is a non-magnetic gap between the first magnet and the second magnet, and the gap is not less than the width of the flux concentrator in the direction of the relative displacement.

7. The vibration power generation module according to claim 6, wherein the weight is installed on the side opposite to the power generation element with respect to the central axis of the vibration of the spring, so that the center of gravity of the magnet part is located on the side of the weight with respect to the central axis.

8. The vibration power generation module according to claim 7, wherein a holding mechanism for holding at an arbitrary position with respect to the total length of the spring is provided.

9. The vibration power generation module according to any one of claims 1 to 8, wherein the magnetic core is made of one or more composite magnetic wires that produce a large Barkhausen effect.

10. A vibration power generation device comprising a rectifying unit that rectifies the voltage output by the power generation element of the power generation module according to any one of claims 1 to 8, and a power storage unit that stores the voltage rectified by the rectifying unit.

11. A vibration power generation device comprising a rectifying unit that rectifies the voltage output by the power generation element of the power generation module according to claim 9, and a power storage unit that stores the voltage rectified by the rectifying unit.

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