JP7356399B2 - Vibration power generation device that can adjust natural frequency and vibration power generation method that can adjust natural frequency - Google Patents

Description

The present invention relates to a vibration power generation device and a vibration power generation method that obtain electric power by vibrating a power generation element, and is capable of adjusting the natural frequency.

In power generation equipment as equipment for supplying electric power (power supply equipment), as the generator is driven, vibrations occur in the generator due to shaking of the motor (rotor) etc. due to electromagnetic force due to excitation. At present, energy from vibration exists as unused energy.

For example, it is conceivable to use the vibration power generation device disclosed in Patent Document 1 to convert energy generated by vibrations in equipment for supplying electric power into electric power. If it is possible to convert the energy generated by vibrations in equipment for supplying electricity into electricity, it becomes possible to effectively utilize unused energy.

By using a vibration power generation element (power generation element) that uses resonance, it is possible to efficiently capture vibration energy and convert it into electric power by matching the natural frequency of the power generation element to the frequency of the vibration source. Adjusting the natural frequency of a power generating element is an extremely important task when using a power generating element.

Although it is possible to adjust the natural frequency by adjusting the structure of the vibration mechanism (base material and weight) of the power generation element, there are currently restrictions on the equipment to which it can be applied. For this reason, the reality is that there is a desire for a technology that can adjust the natural frequency without being subject to restrictions such as the size and structure of the equipment.

JP 2019-134672 Publication

The present invention has been made in view of the above circumstances, and provides a vibration power generation device that can easily adjust the natural frequency without being constrained by the size or structure of the vibration mechanism of the power generation element, and a vibration power generation device that can easily adjust the natural frequency. It is an object of the present invention to provide a vibration power generation method that can be easily adjusted.

To achieve the above object, a vibration power generation device capable of adjusting the natural frequency of the present invention according to claim 1 includes: a magnetic base material including at least a U-shaped frame structure; The present invention is characterized by comprising a vibration power generation means that obtains electric power from the vibration of an attached power generation element, and a magnetization means that adjusts the natural frequency of vibration by changing the magnetization of the base material.

In the present invention according to claim 1, electric power is obtained by vibration of the power generation element. By changing the magnetization of the base material by the magnetization means, the Young's modulus of the base material changes, and the natural frequency of the power generation element is adjusted. Therefore, by changing the magnetization of the base material, it is possible to easily adjust the natural frequency without being constrained by the size or structure of the vibration mechanism of the power generation element.

Generally, when adjusting the natural frequency of a power generation element, it is considered to adjust the structure of the vibration mechanism (base material and weight) of the power generation element. In recent years, vibration power generation devices have been increasingly used as power sources for infrastructure condition monitoring equipment that utilizes IoT (Internet of Things) technology. When utilizing IoT technology, the condition monitoring equipment has an extremely small structure, such as the size of a coin or a dry cell battery, and it is practically impossible to adjust the structure of the vibration mechanism. By applying the present invention, it is possible to easily adjust the natural frequency of even extremely small condition monitoring equipment that utilizes IoT technology without making any structural adjustments (the structure remains unchanged). become.

The vibration power generation device capable of adjusting the natural frequency of the present invention according to claim 2 is the vibration power generation device capable of adjusting the natural frequency according to claim 1, wherein the power generation element of the vibration power generation means is made of a magnetostrictive material. The device is characterized in that it has an element body around which a coil is arranged, and the vibration of the element body causes the coil to generate an electromotive force.

In the present invention according to claim 2, power can be generated using the inverse magnetostrictive effect from the vibration of the element body, and it is particularly easy to match the natural frequency to the vibration of the power supply equipment. Furthermore, the structure is robust and does not break easily even when subjected to large impacts.

Further, the vibration power generation device capable of adjusting the natural frequency of the present invention according to claim 3 is the vibration power generation device capable of adjusting the natural frequency according to claim 1 or claim 2, wherein the base material is a cantilever beam. It is characterized by being supported in the state.

In the present invention according to claim 3, since the base material is supported in a cantilevered state, the natural frequency of the power generating element can be finely adjusted by a slight change in magnetization (by a change in Young's modulus). can.

Further, the vibration power generation device capable of adjusting the natural frequency of the present invention according to claim 4 is the vibration power generation device capable of adjusting the natural frequency according to any one of claims 1 to 3, wherein the magnetization means is a magnet placed near or in contact with the base material for a predetermined period of time.

In the present invention according to claim 4, by arranging a magnet near the base material or bringing the magnet into contact with the base material for a predetermined period of time, the magnetization of the base material is changed and the natural frequency of the power generation element is changed. can be adjusted.

For example, the time period in which the magnet is placed near the base material or in contact with the base material is set to about several seconds to several tens of seconds. After the magnet is removed, the magnetization of the base material remains unchanged due to residual magnetization. The natural frequency of the power generating element is adjusted to the high frequency side or the low frequency side by arranging or bringing the S pole of the magnet into contact with it, or by arranging or bringing the N pole of the magnet into contact with it. .

Further, the vibration power generation device capable of adjusting the natural frequency of the present invention according to claim 5 is the vibration power generation device capable of adjusting the natural frequency according to any one of claims 1 to 3, wherein the magnetization means is characterized in that it is a magnet that is placed near the base material or brought into contact with the base material while maintaining a predetermined distance therebetween.

In the present invention according to claim 5, by maintaining a predetermined distance and arranging the magnet near the base material, it is possible to change the magnetization of the base material and adjust the natural frequency of the power generation element.

For example, the distance at which the magnets are arranged is set to about several centimeters. It is also possible to make contact with the distance being zero. After the magnet is removed, the magnetization of the base material remains unchanged due to residual magnetization. The natural frequency of the power generating element is adjusted to the high frequency side or the low frequency side depending on whether the south pole of the magnet is placed (contacted) or the north pole of the magnet is placed (contacted).

Further, the vibration power generation device capable of adjusting the natural frequency of the present invention according to claim 6 is the vibration power generation device capable of adjusting the natural frequency according to any one of claims 1 to 3, wherein the magnetization means is a magnet that is placed near the base material or brought into contact with the base material while maintaining a predetermined distance for a predetermined period of time.

In the present invention according to claim 6, by maintaining a predetermined distance for a predetermined time and arranging a magnet near the base material (bringing it into contact with the base material), the magnetization of the base material is changed and the natural vibration of the power generating element is changed. The number can be adjusted.

A vibration power generation method capable of adjusting the natural frequency of the present invention according to claim 7 for achieving the above object is a vibration power generation method that obtains electric power by vibrating a power generation element attached to a magnetic base material. The base material includes at least a U-shaped frame structure, the natural frequency of vibration is adjusted by changing the magnetization of the base material, and power generation is performed by obtaining an arbitrary natural frequency. .

In the present invention according to claim 7, by changing the magnetization of the base material and changing the Young's modulus, the resonance frequency is adjusted, and power generation can be performed by obtaining an arbitrary natural frequency. Therefore, by changing the magnetization of the base material, it is possible to easily adjust the natural frequency without being constrained by the size or structure of the vibration mechanism of the power generation element.

The vibration power generation device that can adjust the natural frequency and the vibration power generation method that can adjust the natural frequency of the present invention can easily adjust the natural frequency without being constrained by the size or structure of the vibration mechanism of the power generation element. becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view explaining the schematic structure of the vibration power generation device which can adjust the natural frequency based on one Example of this invention. FIG. 3 is a side view of the vibration power generation device. It is a graph explaining the relationship between voltage and frequency. It is a graph explaining a change in voltage over time. It is a graph explaining the relationship between magnet adsorption time and resonance frequency. FIG. 7 is an external view illustrating a schematic configuration of a vibration power generation device that can adjust the natural frequency according to another embodiment of the present invention. It is a graph explaining the relationship between magnet adsorption time and resonance frequency. FIG. 7 is an external view illustrating a schematic configuration of a vibration power generation device that can adjust the natural frequency according to another embodiment of the present invention. It is a graph explaining the relationship between the distance of the magnet and the resonant frequency. It is a graph explaining the relationship between the distance of the magnet and the resonant frequency.

Embodiments of the present invention will be specifically described below based on the drawings.

FIG. 1 shows an external view of a vibration power generation device (vibration power generation device) that can adjust the natural frequency according to an embodiment of the present invention, and FIG. 2 shows a side view of the vibration power generation device. There is.

As shown in the figure, the vibration power generation device 1 includes vibration power generation means that obtains electric power from the vibrations of the power generation element 2. The power generation element 2 is attached to a U-shaped frame 3 made of a magnetic material, which is a magnetic base material. A magnetostrictive material 4 is attached to the frame 3, and the power generating element 2 is constituted by an element body in which a coil 5 is wound around the magnetostrictive material 4. A vibrator (weight) 6 is attached to the tip of the frame 3.

A magnet 7 for changing magnetization is provided as a magnetization means for adjusting the Young's modulus by changing the magnetization of the frame 3. In addition, 8 in the figure is a fixed magnet attached to the frame 3. As the magnet 7, for example, a magnet with a diameter of 12 mm and a surface magnetic flux density of 30 mT is used.

The frame 3 is attached to a vibration source 11 (for example, a generator or a transformer of power generation equipment), and the vibration of the vibration source 11 gives vibration to the vibrator (weight) 6. When vibration is applied, the vibrator 6 reciprocates, for example, up and down due to inertial force, and the frame 3 is deformed. Due to the deformation of the frame 3, compressive and tensile forces act in the longitudinal direction of the magnetostrictive material 4, the surrounding magnetic flux changes due to the inverse magnetostrictive effect, and an electromotive force is generated in the coil 5 due to electromagnetic induction (electric power is generated).

The natural frequency of the power generation element 2 is adjusted by changing the magnetization of the frame 3 and adjusting the Young's modulus using the magnet 7 as a magnetization means. That is, by placing the magnet 7 near the frame 3 or by bringing the magnet 7 into contact with the frame 3 for a predetermined period of time, the magnetization of the frame 3 changes and the Young's modulus of the frame 3 is arbitrarily adjusted. , the natural frequency of the power generating element 2 is adjusted.

For example, the time the magnet 7 is placed near the frame 3 or the magnet 7 is brought into contact with the frame 3 is set to about several seconds to several tens of seconds. After the magnet 7 is released, the magnetization of the frame 3 remains unchanged due to residual magnetization. Depending on whether the S pole of the magnet 7 is arranged or brought into contact with each other, or the N pole of the magnet 7 is arranged or brought into contact with each other, the natural frequency of the power generation element 2 is shifted to the high frequency side or to the low frequency side. be adjusted.

Therefore, by changing the magnetization of the frame 3 using the magnet 7, the natural frequency of the power generating element 2 is adjusted, and is subject to restrictions on the size of the vibration mechanism of the power generating element 2 and the structure in which the power generating element 2 is provided. In other words, the natural frequency of the power generating element 2 can be easily adjusted without disassembling the structure and improving the vibrator (weight) 6, etc. of the power generating element 2.

Generally, when adjusting the natural frequency of a power generation element, it is considered to adjust the structure of the vibration mechanism (base material and weight) of the power generation element. In recent years, vibration power generation devices have been increasingly used as power sources for infrastructure condition monitoring equipment that utilizes IoT (Internet of Things) technology. When using IoT technology, the condition monitoring equipment has an extremely small structure, making it practically impossible to adjust the structure of the vibration mechanism.

By applying the technology of this embodiment that changes the magnetization of the frame 3 using the magnet 7, even extremely small equipment (condition monitoring equipment) that utilizes IoT technology can be used without making structural adjustments. It becomes possible to easily adjust the natural frequency of the power generation element 2 (while the structure remains unchanged). In other words, delicate and difficult steps such as finely adjusting the installation position of the vibrator (weight) 6 (for example, in μm units) or finely adjusting the mass of the vibrator (weight) 6 (for example, adjusting in mg units) are required. It becomes possible to easily adjust the natural frequency of the power generation element 2 without requiring any work.

In other words, by changing the magnetization of the frame 3, the natural frequency of the power generating element 2 can be easily adjusted without being constrained by the size of the vibration mechanism of the power generating element 2 or the structure in which the power generating element 2 is incorporated. It becomes possible.

The power generation element 2 has an element body in which a coil 5 is arranged around a magnetostrictive material 4, and the vibration of the element body generates an electromotive force in the coil 5. It is possible to generate electricity using the inverse magnetostriction effect based on the frequency, and in particular, the structure has the characteristic that it is easy to match the natural frequency to the vibration of the power supply equipment. In other words, in the power supply equipment, vibrations of 50 Hz or 60 Hz, or multiples thereof, occur in the structure, so it is easy to match the natural frequency to this frequency. Furthermore, the structure is robust and does not break easily even when subjected to large impacts.

In addition, since the frame 3 having the vibrator (weight) 6 and the power generation element 2 is supported in a cantilevered state, the natural frequency of the power generation element 2 can be changed due to a slight change in magnetization (due to a change in Young's modulus). Fine adjustments can be made.

In the vibration power generation device 1 described above, electric power is obtained by the vibration of the power generation element 2, and is supplied as necessary electric power. Therefore, even if the vibration source 11 (for example, a generator or a transformer) has a small vibration acceleration, it is possible to generate the necessary power according to the purpose of use.

If the natural frequency of the power generating element 2 matches the frequency of the vibration source 11, vibration energy can be efficiently captured and converted into electric power. Therefore, in order to match the natural frequency of the power generation element 2 with the frequency of the vibration source 11, the magnetization of the frame 3 is changed to adjust the natural frequency of the power generation element 2, and vibration energy can be efficiently captured. That's what I do.

That is, the natural frequency of the power generation element 2 is adjusted by changing the magnetization of the frame 3 and adjusting the Young's modulus using the magnet 7 as a magnetization means. For example, by placing the magnet 7 near the frame 3 or by bringing the magnet 7 into contact with the frame 3 for a predetermined period of time, the magnetization of the frame 3 can be changed and the Young's modulus of the frame 3 can be arbitrarily adjusted. , adjust the natural frequency of the power generating element 2.

This allows you to fine-tune the installation position of the vibrator (weight) 6 (for example, in μm units) or finely adjust the mass of the vibrator (weight) 6 (for example, in mg units) even for extremely small devices. It becomes possible to easily adjust the natural frequency of the power generation element 2 to match the frequency of the vibration source 11 without performing delicate and difficult work such as adjustment), while leaving the structure of the device as it is. .

As described above, by arbitrarily selecting the S and N poles of the magnets 7 to be placed (contacted), the natural frequency of the power generation element 2 is adjusted to the high frequency side or the low frequency side. After the magnet 7 is released, the magnetization of the frame 3 remains unchanged due to residual magnetization.

The effect of using the magnet 7 will be explained based on FIGS. 3 and 4.

FIG. 3 shows a graph illustrating the relationship between voltage and frequency depending on the S and N poles of the magnets 7 to be placed, and FIG. 4 shows a graph illustrating changes in voltage over time due to residual magnetization.

As shown by the solid line in FIG. 3, when the S pole of the magnet 7 is placed near (in contact with) the frame 3 for the power generation element 2 whose natural frequency (peak) is adjusted to QHz (for example, 100Hz), As shown by the dotted line in FIG. 3, the natural frequency (peak) is adjusted to Qa (eg, a high frequency of about 0.5 Hz). Furthermore, when the N pole of the magnet 7 is placed near (in contact with) the frame 3, the natural frequency (peak) becomes Qb (for example, a frequency as low as 0.5 Hz), as shown by the dashed line in Fig. 3. be adjusted.

In other words, by placing the S pole or N pole of the magnet 7 near the frame 3 for a predetermined period of time (about several seconds to several tens of seconds), the natural frequency of the power generation element 2 can be adjusted to the high frequency side or , can be adjusted to the lower frequency side.

After the magnet 7 is released, the magnetization of the frame 3 remains unchanged due to residual magnetization. That is, using a power generation element 2 whose natural frequency (peak) is, for example, 99.5 Hz, after a few minutes, the S pole of the magnet 7 is placed near (in contact with) the frame 3, and the natural frequency (peak) is set to 99.5 Hz. ) is finely adjusted to QHz (for example, 100Hz).

As shown in FIG. 4, for the first few minutes, there is a deviation from the resonance state with respect to the vibration source 11, so the voltage gradually increases from V1, and after a few minutes, the voltage is increased to V2. After the magnet 7 is released, the magnetization of the frame 3 remains unchanged due to residual magnetization, and the voltage is maintained at V2 even after 240 hours have passed.

That is, after the magnet 7 is released, the magnetization of the frame 3 remains unchanged due to residual magnetization, and vibration energy can be efficiently taken in over a long period of time.

The vibration power generation device 1 described above allows the natural frequency of the power generation element 2 to be easily adjusted without being restricted by the size or structure of the vibration mechanism of the power generation element 2.

Based on FIG. 5, the state of the resonance frequency with respect to the time when the magnet 7 is attracted will be explained.

FIG. 5 shows a graph illustrating the relationship between the attraction time (seconds) and the resonance frequency depending on the S pole and N pole of the magnet 7 to be placed. In the illustrated embodiment, the magnet 7 has a diameter of 12 mm and a surface magnetic flux density of 30 mT.

When the resonant frequency is tuned to 100Hz and the S pole of the magnet 7 is attracted for 0 to 60 seconds, the resonant frequency increases from 100Hz to 100.2Hz, as shown by the ■ mark in the figure. was confirmed. When the N pole of the magnet 7 was attracted for 0 to 60 seconds, it was confirmed that the resonance frequency became low between 100 Hz and 99.4 Hz, as shown by the circle in the figure.

Therefore, by placing (adhering to) the magnet 7 near the frame 3 (oscillator (weight) 6) for a predetermined period of time, the magnetization of the frame 3 is changed and the natural frequency of the power generation element 2 is adjusted. It has been confirmed that this is possible.

Another embodiment will be described based on FIGS. 6 and 7. FIG. 6 shows an external view for explaining a vibration power generation device (vibration power generation device) that can adjust the natural frequency according to another embodiment of the present invention, and FIG. A graph illustrating the relationship between the adsorption time (seconds) and the resonance frequency according to the pole is shown. Note that the same members as those shown in FIGS. 1 and 2 are given the same reference numerals.

As shown in FIG. 6, in the vibration power generation device 21, three power generation elements 2 are arranged side by side and attached to the vibration source 11, and one vibrator (weight) 16 is attached to the tips of the three frames 3. . A magnet 7 for changing magnetization is provided as a magnetization means for adjusting the Young's modulus by changing the magnetization of the frame 3. As the magnet 7, for example, a magnet with a diameter of 12 mm and a surface magnetic flux density of 30 mT is used.

When the resonant frequency is tuned to 120Hz and the S pole of the magnet 7 is attracted for 0 to 60 seconds, the resonant frequency increases from 120Hz to 120.4Hz, as shown by the ■ mark in Figure 7. This was confirmed. When the N pole of the magnet 7 was attracted for 0 seconds to 60 seconds, it was confirmed that the resonance frequency became low between 120 Hz and 119.4 Hz, as shown by the circle in FIG.

Therefore, by placing (adhering to) the magnet 7 near the frame 3 (oscillator (weight) 16) for a predetermined period of time, the magnetization of the frame 3 is changed and the natural frequency of the power generation element 2 is adjusted. It has been confirmed that this is possible.

By arranging (adsorbing) the magnet 7 near the frame 3 (vibrator (weight) 16) for a predetermined period of time, the resonance frequency can be changed in the same manner as when there is only one power generation element 2. It was confirmed that it can be done. Therefore, the natural frequency of the power generating element 2 can be adjusted regardless of the form of the power generating element 2 or the original tuned resonance frequency.

An example in which the distance between the magnets is adjusted will be described based on FIGS. 8 to 10.

FIG. 8 shows an external view for explaining a vibration power generation device (vibration power generation device) that can adjust the natural frequency according to an embodiment in which the distance between the magnets is adjusted, and FIG. 9 shows the S of the magnet 7 to be arranged. A graph illustrating the relationship between the arrangement distance (cm) and the resonant frequency according to the pole and north pole is shown. Note that the same members as those shown in FIGS. 1 and 2 are given the same reference numerals.

As shown in FIG. 8, the vibration power generation device 1 is provided with a magnet 37 for changing magnetization as a magnetization means for adjusting the Young's modulus by changing the magnetization of the frame 3. As the magnet 37, for example, a magnet with a diameter of 80 mm and a surface magnetic flux density of 100 mT is used.

In a situation where the resonance frequency is tuned to 100Hz, if the N pole of the magnet 37 is kept at a predetermined distance between 8cm and 0cm, the resonance frequency will change between 100Hz and 99.1Hz, as shown by the circle in Figure 9. was confirmed to be lower. When the S pole of the magnet 37 was kept at a predetermined distance between 8 cm and 0 cm, it was confirmed that the resonant frequency increased between 100 Hz and 100.6 Hz, as shown by the ■ mark in Figure 9. .

Therefore, it has been confirmed that by arranging (adhering) the magnets 37 such that the predetermined distance is gradually shortened, the magnetization of the frame 3 can be changed and the natural frequency of the power generation element 2 can be adjusted.

FIG. 10 shows a graph illustrating the relationship between the arrangement distance (cm) and the resonant frequency according to the S pole and N pole of the magnet 37 arranged for the vibration power generation device 21 shown in FIG. 6. . Note that the same members as those shown in FIGS. 1, 2, and 6 are given the same reference numerals.

When the N pole of the magnet 37 is maintained at a predetermined distance between 8 cm and 0 cm with the resonance frequency tuned to 120 Hz for the vibration power generation device 21 in which three power generation elements 2 are arranged side by side and attached to the vibration source 11. As shown by the circle in the figure, it was confirmed that the resonance frequency became low between 120Hz and 119.2Hz. When the S pole of the magnet 37 was kept at a predetermined distance between 8 cm and 0 cm, it was confirmed that the resonance frequency increased between 120 Hz and 120.6 Hz, as shown by the black mark in the figure.

Therefore, it has been confirmed that by arranging (adhering) the magnets 37 such that the predetermined distance is gradually shortened, the magnetization of the frame 3 can be changed and the natural frequency of the power generation element 2 can be adjusted.

It was also confirmed that by arranging (adhering) the magnets 37 so that the predetermined distance gradually becomes shorter, the resonance frequency can be changed in the same manner as when there is only one power generation element 2. Therefore, the natural frequency of the power generating element 2 can be adjusted regardless of the form of the power generating element 2 or the original tuned resonance frequency.

In addition to adjusting the distance at which the magnets 37 are arranged, by adjusting the time at which they are arranged, it becomes possible to further adjust the natural frequency of the power generation element 2.

In the above embodiment, the natural frequency of the magnetostrictive power generating element 2 is adjusted by changing the magnetization of the frame 3 held in a cantilevered state. Even in the case of a vibration power generation device in which a piezoelectric element (power generation element) is attached to a base material, the natural frequency of the piezoelectric element can be adjusted by changing the magnetization of the base material.

INDUSTRIAL APPLICATION This invention can be utilized in the industrial field of the vibration power generation device which vibrates a power generation element and obtains electric power, and the vibration power generation method.

1, 21 Vibration power generation device 2 Power generation element 3 Frame 4 Magnetostrictive material 5 Coil 6, 16 Vibrator (weight)
7, 37 Magnet 8 Fixed magnet 11 Vibration source

Claims (7)

a magnetic substrate comprising at least a U-shaped frame structure;
vibration power generation means that obtains electric power by vibration of a power generation element attached to the magnetic base material;
A vibration power generation device capable of adjusting the natural frequency, comprising magnetization means for adjusting the natural frequency of vibration by changing the magnetization of the base material. The vibration power generation device capable of adjusting the natural frequency according to claim 1,
The power generation element of the vibration power generation means is:
It has an element body in which a coil is arranged around a magnetostrictive material,
A vibration power generation device capable of adjusting a natural frequency, characterized in that an electromotive force is generated in the coil by vibration of the element body. In the vibration power generation device capable of adjusting the natural frequency according to claim 1 or claim 2,
The base material is supported in a cantilevered state. A vibration power generation device capable of adjusting a natural frequency. In the vibration power generation device capable of adjusting the natural frequency according to any one of claims 1 to 3,
The magnetizing means includes:
A vibration power generation device capable of adjusting a natural frequency, characterized in that the device is a magnet placed near the base material or brought into contact with the base material for a predetermined period of time. In the vibration power generation device capable of adjusting the natural frequency according to any one of claims 1 to 3,
The magnetizing means includes:
A vibration power generation device capable of adjusting a natural frequency, characterized in that the magnet is placed near the base material or brought into contact with the base material while maintaining a predetermined distance. In the vibration power generation device capable of adjusting the natural frequency according to any one of claims 1 to 3,
The magnetizing means includes:
A vibration power generation device capable of adjusting a natural frequency, characterized in that the magnet is placed near the base material or brought into contact with the base material while maintaining a predetermined distance for a predetermined time. In a vibration power generation method in which electric power is obtained by vibrating a power generation element attached to a magnetic base material , the base material includes at least a U-shaped frame structure, and the vibration is generated by changing the magnetization of the base material. A vibration power generation method capable of adjusting the natural frequency, characterized in that the natural frequency of the vibration is adjusted to obtain an arbitrary natural frequency to generate electricity.

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