JP7256526B2 - Vibration power generator and electronic device using the same - Google Patents

Description

The present invention relates to a vibration power generator that uses vibration to generate power and an electronic device using the same .

In recent years, with the aim of realizing a sustainable recycling-based society, it is being considered to replace various energies with energy harvesting power. For example, transportation infrastructure that was built rapidly during the high-growth period has been rapidly aging for 50 years. On the other hand, Japan's population growth has already slowed and is set to decline in the near future, so it is clear that it will become increasingly difficult to secure maintenance workers. Therefore, the need for efficient maintenance of bridges, for example, has led to the development of systems for automatically monitoring cracks and damage in concrete. Aiming at a low-carbon society, the use of an energy harvesting device as a power supply for driving the system is under consideration.

Vibration power generators have been attracting attention as the energy harvesting device, and many devices using magnetostrictive materials for the power generation elements of the vibration power generators have been studied. As an example using a magnetostrictive material, a structure is disclosed in which a passing load of an electric train is applied to a power generation element in which a coil is wound around a magnetostrictive material. Specifically, a magnetostrictive element wound with a coil is installed in a hole formed in a sleeper for fixing the rail, and the magnetostrictive element is arranged so as to be sandwiched between the bottom surface of the hole and the rail. In this vibration power generator, when a train passes on the rail, the load of the train distorts the magnetostrictive element placed between the rail and the bottom of the hole in the sleeper, and electric power corresponding to this distortion is generated. (see, for example, Patent Document 1).

JP-A-10-271858

In Patent Literature 1, the railroad tracks, sleepers, and the like receive large loads from passing vehicles. Therefore, the dynamic system is generally expressed as a forced displacement model that gives a constant displacement to the input section with respect to the base section of the power generator. At this time, if the forced displacement becomes excessively large, the stress applied to the power generation element increases in proportion to the displacement, and there is a risk of reaching the breaking stress, and there is room for improvement. Incidentally, in order to avoid reaching the breaking stress, it is conceivable to lengthen the total length of the power generating element and reduce the strain applied to the power generating element (amount of deformation per unit length), but the size of the power generating device is limited. It is difficult to invite and implement.

Therefore, the present invention has been made in view of such a situation, and an object thereof is to provide a vibration power generation apparatus and an electronic device using the same that can suppress the reaching of breaking stress while suppressing an increase in size.

That is, in order to solve the above-described problems, the vibration power generator of the present invention is provided with an input section configured of a magnetic material for receiving vibrations from a vibration source and fixed to a fixing section facing the input section. a base portion; and conversion means disposed between the input portion and the base portion for converting vibration input from the input portion into electric power, wherein the conversion means includes the input portion and the base portion. a magnetostrictive member arranged inside or outside the magnetic coil and made of a magnetostrictive material, and arranged outside or inside the magnetic coil to form a magnetic circuit and a magnetic circuit forming portion, wherein an elastic member that expands and contracts due to vibration input from the input portion to the converting means is provided between the converting means and the base portion.

According to the above configuration, the magnetic circuit forming portion can effectively change the magnetic flux density from the strain of the magnetostrictive member. In this state, when vibration from the vibration source is input to the input portion, compressive stress is applied to the magnetostrictive member. Due to this compressive stress, the magnetic flux density inside the magnetostrictive member changes, and the magnetic flux passing through the magnetic coil changes to generate power. In addition, compressive stress applied to the magnetostrictive member is relieved by deformation of the elastic member due to the force applied to the input portion. As a result, damage to the magnetostrictive member due to overload can be suppressed without increasing the total length of the magnetostrictive member.

Further, in the vibration power generator of the present invention, the conversion means includes the magnetostrictive member positioned at the center, the magnetic coil arranged outside the magnetostrictive member, and the magnetic coil arranged outside the magnetic coil. and a circuit forming portion, and the magnetic circuit forming portion may include at least a permanent magnet.

Further, in the vibration power generator of the present invention, the conversion means comprises the magnetic circuit forming portion located in the center, the magnetic coil arranged outside the magnetic circuit forming portion, and the magnetic coil arranged outside the magnetic circuit forming portion. and the magnetostrictive member, and the magnetic circuit forming portion may include at least a permanent magnet.

Further, the vibration power generator of the present invention may include a weight disposed between the conversion means and the elastic member, one end of which is connected to the conversion means, and the other end of which is connected to the elastic member. .

As described above, the amount of power generated can be increased by generating continuous vibration through the action of the weight and the elastic member.

Moreover, in the present invention, the input section may be in contact with the magnetostrictive member.

Further, the present invention may be an electronic device used as a power source for the vibration power generation device to apply an electric current for cathodic protection to a bridge.

According to the above configuration, by using the vibration power generation device as an electronic device that is used as a power source for applying an electric current for cathodic protection to the bridge, it is possible to suppress the early generation of rust in the steel material used for the bridge. It can extend the period of regular inspection of bridges.

ADVANTAGE OF THE INVENTION According to the present invention, a vibration power generator and an electronic device using the same are provided, which are capable of suppressing an increase in size and suppressing breaking stress by relaxing compressive stress applied to a magnetostrictive member by an elastic member. can be done.

1 is a perspective view of a vibration power generator according to the present invention; FIG. It is a longitudinal cross-sectional view of the same vibration power generator. It is the schematic which installed the same vibration electric power generating apparatus in the bridge. It is the block diagram which connected the storage battery to the same vibration electric power generating apparatus through the electrical storage circuit. It is the circuit diagram which connected the electrical storage capacitor via the rectifier to the same vibration electric power generating apparatus. 5 is a graph showing the result of analysis of the amount of power generated with respect to the weight of the weight of the same vibration power generator when the action time of the half sine wave is 0.1 to 0.5 ms. FIG. 10 is a graph showing the result of analysis of the amount of power generated with respect to the weight of the weight of the same vibration power generator when the half sine wave has an action time of 1 to 2 ms. FIG. 4 is a graph showing the amount of displacement of the bridge due to the passage of vehicles in the vicinity of the bearing portion of the viaduct of the expressway. FIG. 9 is a graph showing calculation results of the amount of power generation with respect to the amount of displacement of the bridge in FIG. 8. FIG. It is a longitudinal cross-sectional view which shows another structure of the same vibration electric power generating apparatus.

An embodiment of a vibration power generator according to the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the vibration power generator 1 receives vibration from a vibration source (a bridge 14 to be described later), and has an input portion 2 made of a magnetic material and a fixed portion (a bridge pier 15 to be described later). a base portion 3 which is fixed to the input portion 2 and arranged to face the input portion 2 in the vertical direction; 4 and . A cylindrical casing (not shown) covering the outer periphery of the vibration power generator 1 may be provided.

The input unit 2 is made of SUS430, which is an example of magnetic ferritic stainless steel, but may be made of a magnetic material such as martensitic stainless steel, carbon steel, or silicon steel. The input unit 2 is configured in a circular plate shape in a plan view, and has a function of applying a compression stress to the magnetostrictive member 5 described later by inputting vibration from a vibration source (a bridge 14 described later). A protrusion 2T is provided at the center of the lower end of the input section 2 so as to protrude downward and come into contact with the outer surface of the upper end of the magnetostrictive member 5, which will be described later, to position the magnetostrictive member 5 in the horizontal direction. A plurality of protrusions 2T may be provided along the circumferential direction in a plan view, or may be formed in an annular shape.

The base portion 3 includes a cylindrical portion 3A with an open top for accommodating a coil spring 9, which will be described later, and a substantially disc-shaped flange portion 3B projecting outward from the lower end of the cylindrical portion 3A. A plurality of bolt holes 3b for bolting the base portion 3 to a fixing portion (a bridge pier 15 of a bridge 14 to be described later) are formed along the circumferential direction in the flange portion 3B. Although the material of the base portion 3 is not particularly limited, it may be composed of various metals, and depending on the circumstances, may be composed of various synthetic resins.

The conversion means 4 includes a magnetostrictive member 5 made of a magnetostrictive material, a magnetic member 6 arranged outside the magnetostrictive member 5, a magnetic coil 7 arranged (wound) outside the magnetostrictive member 5, a magnetostrictive and a permanent magnet 8 for applying a magnetic bias to the member 5 . The magnetic circuit forming portion is composed of the magnetic member 6 and the permanent magnet 8, but the magnetic circuit forming portion may be composed of at least the permanent magnet 8 alone.

As the magnetostrictive member 5, Galfenol (Fe (iron)-Ga (gallium) alloy) is used in this embodiment, but Terfenol-D (Tb-Dy-Fe alloy) may be used. Other magnetostrictive materials may be used.

The magnetic member 6 has a circular (ring) shape with a rectangular cross section, and is composed of a yoke made of magnetic SUS430. In this embodiment, the magnetic member 6 is made of SUS430, which is an example of ferritic stainless steel having excellent strength and corrosion resistance. good too.

As the permanent magnet 8, a samarium-cobalt magnet magnetized in the axial direction and having a rectangular cross-sectional shape and an annular shape (ring shape) is used. A samarium-cobalt magnet has the advantage of having a strong magnetic force, is resistant to rusting, and has excellent temperature characteristics, but it may be a neodymium magnet, a ferrite magnet, or an alnico magnet.

Further, a coil spring 9 as an elastic member that expands and contracts due to vibration input from the input section 2 to the conversion means 4 is provided between the conversion means 4 and the base part 3 and arranged between the conversion means 4 and the coil spring 9. A weight 10 made of a magnetic material is provided. The coil spring 9 is vertically arranged in series with the magnetostrictive member 5 via the weight 10 and housed inside the base portion 3 . The weight 10 has one end (upper end) connected to the conversion means 4 and the other end (lower end) connected to the coil spring 9 . By generating continuous vibration by the action of the weight 10 and the coil spring 9, the power generation amount can be increased.

The weight 10 has a substantially cylindrical shape and is composed of a receiving portion on which all the members constituting the converting means 4 can be placed. A protrusion 10T is provided at the center of the upper end of the weight 10 to protrude upward and contact the outer surface of the lower end of the magnetostrictive member 5 to position the magnetostrictive member 5 in the horizontal direction. A plurality of protrusions 10T may be provided along the circumferential direction in a plan view, or may be formed in an annular shape.

A vertical gap 11 is formed between the upper end 3a of the cylindrical portion 3A of the base portion 3 and the lower end 10A of the weight 10. As shown in FIG. This gap 11 prevents the weight 10 from being unable to move up and down due to the lower end 10A of the weight 10 coming into contact with the upper end 3a of the cylindrical portion 3A of the base portion 3 due to the vibration input to the input portion 2. It is a gap formed for The gap 11 is set to have a larger vertical dimension than gaps 12 and 13, which will be described later. Further, the rigidity of the coil spring 9 is set so that the magnetostrictive member 5 is not destroyed by vibrations input to the input portion 2 . Specifically, the vibration generated in the bridge 14 described later is measured in advance, the maximum value of the vibration amplitude of the bridge 14 is estimated, and the stiffness of the coil spring 9 is adjusted so that the magnetostrictive member 5 is not destroyed even by the maximum vibration amplitude. to adjust. Thereby, destruction of the magnetostrictive member 5 can be prevented.

The magnetostrictive member 5 is arranged between the input portion 2 and the weight 10 and arranged at the center of the weight 10 . A magnetic coil 7 is arranged concentrically outside the magnetostrictive member 5 with its axis parallel to the direction in which the input portion 2 and the base portion 3 face each other. arranged in a shape. In FIG. 2, the permanent magnet 8 is arranged on the base portion 3 side and the magnetic member 6 is arranged on the input portion 2 side. It may be arranged on the part 3 side. Therefore, by applying a bias magnetic field to the magnetostrictive member 5 by the permanent magnet 8, the permanent magnet 8, the magnetic member 6, the input portion 2, the magnetostrictive member 5, and the weight 10 form a magnetic circuit.

When vibration is input to the input portion 2, a compressive stress is applied from the input portion 2 to the magnetostrictive member 5. This compressive stress is applied to the upper end 7A of the magnetic coil 7 and the upper end 6A of the magnetic member 6, causing the magnetic coil to move. The upper end 7A of the magnetic coil 7 and the upper end 6A of the magnetic member 6 are made lower than the upper end of the magnetostrictive member 5 so that the magnetic member 6 and the magnetic member 6 are not damaged. That is, when no vibration is input to the input portion 2, the upper end 5A of the magnetostrictive member 5 is in contact with the lower end 2B of the input portion 2, but the upper end 7A of the magnetic coil 7 and the lower end 2B of the input portion 2 A gap 12 is formed therebetween, and a gap 13 is formed between the upper end 6A of the magnetic member 6 and the lower end 2B of the input portion 2. As shown in FIG. These gaps 12 and 13 are preferably set so that the lower end 2B of the input portion 2 does not contact the upper end 7A of the magnetic coil 7 and the upper end 6A of the magnetic member 6 when the maximum vibration is input.

As shown in FIG. 3, the vibration power generation device 1 configured as described above is attached to a bridge 14 (a road viaduct in this embodiment). Specifically, the base portion 3 is fixed to the upper end of the bridge pier 15, and the input portion 2 is in contact with the lower end 16B of the steel deck 16 so as to support part of the weight of the steel deck 16. The steel floor slab 16 is a floor slab using a steel plate called a deck plate, and is supported by the pier 15 via bearings 26 , 26 . A paved road (not shown) through which the vehicle C can pass is placed on the floor slab. Compressive stress is applied to the magnetostrictive member 5 when vibration from the steel deck 16 which is the vibration source is input to the input unit 2 . As a result, the magnetic flux density inside the magnetostrictive member 5 changes, and the magnetic flux passing through the magnetic coil 7 wound around the magnetostrictive member 5 changes to generate power. In addition, compressive stress applied to the magnetostrictive member 5 can be alleviated by deforming the elastic member (the coil spring 9 in FIG. 2) upon receiving the force applied to the input portion 2 . Therefore, damage to the magnetostrictive member 5 due to overload can be suppressed without increasing the total length of the magnetostrictive member 5 . In addition, the weight 10 and the elastic member (in FIG. 2, the coil spring 9) generate continuous vibration, thereby increasing the amount of power generation.

In FIG. 3 , a storage battery 17 for accumulating power generated by the vibration power generator 1 is connected to the vibration power generator 1 , and an electrode 18 for energizing with the power from the storage battery 17 is connected to the storage battery 17 . The electrodes 18 are provided on the steel plate portions at the ends of the steel floor slab 16 and suppress rusting of the steel floor slab 16 by energizing. The timing of energizing the electrodes 18 may be set in advance, or it may be raining based on detection information from a sensor (not shown) that detects that it is raining. It may be configured to be energized only when

Actually, as shown in FIG. 4, the vibration power generator 1 is connected to the storage battery 17 via the storage circuit 19 . The storage circuit 19 controls the voltage or current generated by the vibration power generation device 1 so that the storage battery 17 can store power efficiently.

Also, FIG. 5 shows a case where a storage capacitor (capacitor) 20 is used in place of the storage battery 17 . In this case, a rectifier 21 for half-wave rectifying the current from the vibration power generator 1 is provided. In FIG. 5, the resistance component included in the magnetic coil 7 (same as the sign of L in FIG. 5) that constitutes the vibration power generator 1 is indicated by the sign R. As shown in FIG.

6 and 7 show graphs showing the results of analysis of the relationship between the mass of the weight 10 of the vibration power generator 1 and the power generation amount. It should be noted that these graphs show the results obtained when the forced displacement input to the input unit 2 is a half sine wave. In addition, in FIG. 6, the action time during which the sine half wave acts is 0.1 ms (solid line), 0.2 ms (one-dot chain line), 0.3 ms (dashed line), and 0.5 ms (two-dot chain line). In FIG. 7, the action time during which the sine half wave acts is 1.0 ms (solid line), 1.2 ms (one-dot chain line), 1.5 ms (broken line), and 2.0 ms (two-dot chain line). It has one action time. The stiffness of the coil spring 9 of the vibration power generator 1 is set to 1/10 of the axial stiffness of the magnetostrictive member 5, and is set to reduce the forced displacement input to the input section 2 to 1/11. From the above two graphs, it can be seen that in the case of an input waveform with a short acting time, the change in magnetic flux density is fast, so the generated power is large. Further, when the mass of the weight 10 becomes heavy, the inertial force of the weight 10 increases and the vibration amplitude of the weight 10 increases, so that a large amount of generated power can be obtained.

Also, FIG. 8 shows the displacement of the bridge when the vibration generated in the bridge was actually measured by the sensor. The graph in FIG. 9 shows the amount of power generated when the displacement of the bridge in FIG. 8 is input to the vibration power generator 1 of the present invention. Also in this case, similarly to the result of the half sine wave, the power generation amount increases as the mass of the weight 10 increases.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, the conversion means 4 is arranged between the input portion 2 and the weight 10, and includes a permanent magnet 22 and a magnetic member 23 forming a magnetic circuit forming portion located at the center of the weight 10, and an outer side of the magnetic circuit forming portion. and a magnetostrictive member 25 concentrically arranged outside the magnetic coil 24 . 2, the upper end 25A of the magnetostrictive member 25 is in contact with the lower end 2B of the input section 2, but a gap 12 is formed between the upper end 24A of the magnetic coil 24 and the lower end 2B of the input section 2. , a gap 13 is formed between the upper end 23A of the magnetic member 23 and the lower end 2B of the input portion 2. As shown in FIG. In this case, by applying a bias magnetic field to the magnetostrictive member 25 by the permanent magnet 22 , the permanent magnet 22 , the magnetic member 23 , the input section 2 , the magnetostrictive member 25 and the weight 10 form a magnetic circuit. Here, the magnetic circuit forming portion includes the permanent magnet 22 and the magnetic member 23, but at least the permanent magnet 22 is sufficient, and the magnetic member 23 may be omitted. The magnetostrictive member 25 is configured to have a larger diameter and volume than the magnetostrictive member 5 shown in FIGS. 1 and 2 . At the center of the lower end of the input section 2, there is provided a protrusion 2T that protrudes downward and abuts against the outer surface of the upper end of the magnetic coil 24 to position the magnetic coil 24 in the horizontal direction. A plurality of protrusions 2T may be provided along the circumferential direction in a plan view, or may be formed in an annular shape. A projection 10T is provided at the center of the upper end of the weight 10 so as to protrude upward and contact the outer surface of the lower end of the magnetic coil 24 to position the magnetic coil 24 in the horizontal direction. A plurality of protrusions 10T may be provided along the circumferential direction in a plan view, or may be formed in an annular shape. The permanent magnet 22 is arranged on the base portion 3 side and the magnetic member 23 is arranged on the input portion 2 side. may be placed. 10 are the same as those in FIG.

In the above-described embodiment, the vibration power generator 1 is used as a power source for suppressing corrosion of the steel plate portion due to the generation of rust in road viaducts, and as a power source for IoT devices in traffic infrastructure such as road viaducts and iron bridges. good too. This can be used as a power supply for monitoring the deterioration of bridge structures, or as a power supply for lighting fixtures that illuminate specific parts of bridge structures, or as a mechatronics for transportation infrastructure such as a support information transmission system for autonomous driving. It can also be used as a power supply for the realization of Also, by installing the vibration power generation device 1 on the tire of an automobile, it can be used as a power source for a road surface condition detection system, or by installing it on the heel of a shoe, it can generate power by walking and monitor human body information. may be used.

Further, although the weight 10 is provided in the above embodiment, the weight 10 may be omitted depending on the case.

Further, in the above embodiment, the coil spring 9 is used as the elastic member, but an elastic member made of a plate spring, a metal block, a synthetic resin, or the like may be used.

In the above embodiment, the projections 2T and 10T for positioning the members are provided on the input section 2 and the weight 10, but the projections 2T and 10T may be omitted.

DESCRIPTION OF SYMBOLS 1... Vibration power generator, 2... Input part, 2B... Lower end, 2T... Projection part, 3... Base part, 3A... Cylindrical part, 3B... Flange part, 3a... Upper end, 3b... Bolt hole, 4... Conversion means, 5 Magnetostrictive member 5A Upper end 6 Magnetic member 6A Upper end 7 Magnetic coil 7A Upper end 8 Permanent magnet 9 Coil spring (elastic member) 10 Weight 10A Lower end 10T Protrusion Parts 11, 12, 13 Gap 14 Bridge 15 Bridge pier 16 Steel deck 16B Lower end 17 Storage battery 18 Electrode 19 Storage circuit 20 Storage capacitor (capacitor) 21 Rectifier 22 Permanent magnet 23 Magnetic member 23A Upper end 24 Magnetic coil 24A Upper end 25 Magnetostrictive member 25A Upper end 26 Bearing C Vehicle

Claims (10)

A plate-shaped input portion configured of a magnetic material to which vibration from a vibration source is input, a base portion that faces the input portion and is fixed to a fixed portion, and between the input portion and the base portion and a conversion means arranged to convert vibration input from the input unit into electric power,
The conversion means includes: a magnetic coil having an axis along the direction in which the input section and the base section face each other; a magnetostrictive member arranged inside or outside the magnetic coil and made of a magnetostrictive material; a magnetic circuit forming part for forming a magnetic circuit arranged outside or inside,
The upper end of the magnetic circuit forming portion is lower than the upper end of the magnetostrictive member,
A vibration power generator comprising an elastic member that expands and contracts due to vibration input from the input portion to the conversion means, between the conversion means and the base portion. An input portion configured of a magnetic material for receiving vibration from a vibration source, a base portion facing the input portion and fixed to a fixing portion, and disposed between the input portion and the base portion, A conversion means for converting vibration input from the input unit into electric power,
The conversion means comprises: a magnetic coil having an axis along a direction in which the input portion and the base portion face each other; a magnetostrictive member arranged outside the magnetic coil and made of a magnetostrictive material; a magnetic circuit forming part for forming a magnetic circuit disposed inside the magnetic coil,
The magnetic circuit forming unit includes at least a permanent magnet,
A vibration power generator comprising an elastic member that expands and contracts due to vibration input from the input portion to the conversion means, between the conversion means and the base portion. The conversion means includes the magnetostrictive member positioned at the center, the magnetic coil arranged outside the magnetostrictive member , and the magnetic circuit forming portion arranged outside the magnetic coil, and the magnetic 2. The vibration power generator according to claim 1, wherein the circuit forming part includes at least a permanent magnet. 4. Among claims 1 to 3, further comprising a weight arranged between said converting means and said elastic member, one end of which is connected to said converting means, and the other end of which is connected to said elastic member. Vibration power generator according to any one of the above. The vibration power generator according to any one of claims 1 to 4, wherein the input portion is in contact with the magnetostrictive member. An input portion configured of a magnetic material for receiving vibration from a vibration source, a base portion facing the input portion and fixed to a fixing portion, and disposed between the input portion and the base portion, conversion means for converting vibration input from the input section into electric power; an elastic member that expands and contracts due to the vibration input from the input section to the conversion means; disposed between the conversion means and the elastic member; a weight having one end connected to the converting means and the other end connected to the elastic member;
The conversion means includes: a magnetic coil having an axis along the direction in which the input section and the base section face each other; a magnetostrictive member arranged inside or outside the magnetic coil and made of a magnetostrictive material; a magnetic circuit forming part for forming a magnetic circuit arranged outside or inside,
The weight is configured as a receiving portion on which the magnetic coil, the magnetostrictive member, and the magnetic circuit forming portion can be placed on one end side,
A gap is formed between the input section and the magnetic coil and the magnetic circuit forming section,
The magnetostrictive member is in contact with the input portion and the weight,
A vibration power generator, wherein a magnetic circuit is formed by the magnetic circuit forming portion, the input portion, the magnetostrictive member, and the weight. An input portion configured of a magnetic material for receiving vibration from a vibration source, a base portion facing the input portion and fixed to a fixing portion, and disposed between the input portion and the base portion, conversion means for converting vibration input from the input section into electric power; an elastic member that expands and contracts due to the vibration input from the input section to the conversion means; disposed between the conversion means and the elastic member; a weight having one end connected to the converting means and the other end connected to the elastic member;
The conversion means includes: a magnetic coil having an axis along the direction in which the input section and the base section face each other; a magnetostrictive member arranged inside or outside the magnetic coil and made of a magnetostrictive material; a magnetic circuit forming part for forming a magnetic circuit arranged outside or inside,
The magnetostrictive member is in contact with the input portion and the weight,
A gap is formed between the input section and the magnetic coil and the magnetic circuit forming section,
A vibration power generator, wherein a gap larger than the gap between the input section and the magnetic coil and the magnetic circuit forming section is formed between the weight and the base section. The conversion means includes the magnetostrictive member positioned at the center, the magnetic coil arranged outside the magnetostrictive member, and the magnetic circuit forming portion arranged outside the magnetic coil, and the magnetic 8. The vibration power generator according to claim 6, wherein the circuit forming part includes at least a permanent magnet . The conversion means comprises the magnetic circuit forming portion located in the center, the magnetic coil arranged outside the magnetic circuit forming portion, and the magnetostrictive member arranged outside the magnetic coil, 8. The vibration power generator according to claim 6, wherein the magnetic circuit forming part includes at least a permanent magnet . 10. An electronic device, wherein the vibration power generator according to any one of claims 1 to 9 is used as a power source for supplying electric current to a bridge for cathodic protection.

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