JP7557357B2 - Magnetostrictive power generation device - Google Patents

Description

The present invention relates to a magnetostrictive power generation device.

In the use of the Internet of Things (IoT), which has developed in recent years, wireless sensor modules that integrate sensors, power sources, wireless communication devices, etc. are used to connect things to the Internet. There is a demand for the development of power generation devices that can generate electricity from energy generated in the environment where the device is installed as a power source for such wireless sensor modules, without the need for regular manual maintenance such as battery replacement and charging.

One example of such a power generation device is a magnetostrictive vibration power generation device that uses inverse magnetostriction, which is the reverse effect of magnetostriction. Inverse magnetostriction is a phenomenon in which the magnetization of a magnetostrictive material changes when strain is applied to the magnetostrictive material due to vibration or other reasons. Magnetostrictive vibration power generation applies strain to a magnetostrictive material through vibration, and the change in magnetization caused by the inverse magnetostrictive effect generates an electromotive force in a coil wound around the magnetostrictive element according to the law of electromagnetic induction.

In the past, attempts have been made to increase the amount of magnetostriction in order to improve the power generation performance of magnetostrictive materials. This is because the greater the amount of magnetostriction, the greater the change in magnetic flux density (ΔB) due to inverse magnetostriction when the magnetostrictive material is alternately loaded with tensile strain and compressive strain, and the greater the power generation output. From this perspective, materials with large amounts of magnetostriction such as FeGa alloys, FeCo alloys, and FeAl alloys have been developed, and power generation devices using these magnetostrictive materials have also been developed (Patent Documents 1 to 6).

For example, in the power generation device described in Patent Document 1, in order to improve power generation performance and reduce quality variation, a magnetostrictive material and a soft magnetic material are bonded together, and the magnetization of the soft magnetic material is changed by the magnetization of the magnetostrictive material. In this way, in addition to the voltage caused by the change in magnetization of the magnetostrictive material, a voltage caused by the change in magnetization of the soft magnetic material is also induced in the detection coil. Examples of magnetostrictive materials used include FeCo, FeAl, Ni, NiFe, and NiCo, and examples of soft magnetic materials include Fe, FeNi, FeSi, and electromagnetic stainless steel.

The power generation device described in Patent Document 2 discloses an actuator having a structure in which a parallel beam structure is created by combining magnetostrictive material and magnetic material, and the magnetic material is used in a state where it is magnetically saturated by a bias magnetic field, in order to improve electromotive force, reduce manufacturing costs, and improve mass productivity. In this actuator, the back yoke is U-shaped, the neutral surface is provided outside the magnetostrictive material, and the electromotive force is improved by superimposing the change in the bias magnetic field due to vibration on the change in magnetization of the magnetostrictive material. As magnetostrictive materials, FeGa, FeCo, FeAl, FeSiB, amorphous materials, etc. are described, and as magnetic materials, SPCC, carbon steel (SS400, SC, SK, SK2), ferritic stainless steel (SUS430), etc. are described.

Patent Document 3 discloses a power generating element in which a magnetostrictive material is bonded to a non-magnetic material as a reinforcing material in order to improve power generation efficiency and apply a uniform stress load, and the cross-sectional area ratio of the magnetostrictive material to the reinforcing material is specified to be reinforcing material/magnetostrictive material > 0.8. Examples of magnetostrictive materials listed include FeGa, FeCo, FeNi, etc., and examples of reinforcing materials listed include filler-containing resin, Al, Mg, Zn, Cu, etc.

The power generation device of Patent Document 4 employs a structure that allows the number of turns of the coil to be increased in order to improve the power generation output. Specifically, a structure is created in which a magnetostrictive plate and a non-magnetic structure are surface-bonded, and a magnetic field is returned from the magnetostrictive plate to a U-shaped yoke around which a coil is wound. FeGa and FeCo are described as the magnetostrictive plate, and stainless steel (SUS304, etc.) is described as the non-magnetic structure.

In the power generation device of Patent Document 5, in order to improve power generation efficiency and apply uniform stress, a structure is fabricated by bonding a magnetostrictive material and a non-magnetic material (reinforcement material), and the structure is used as two parallel beams. Examples of magnetostrictive materials described in this document include FeGa, FeCo, FeCo-based amorphous, Fe-based amorphous, Ni-based amorphous, metamagnetic shape memory alloy, and ferromagnetic shape memory alloy, while examples of non-magnetic materials described in this document include silicon oxide, alumina, polyimide, polycarbonate, fiber-reinforced plastic, and non-magnetic metals (Al, Cu).

In the power generation device of Patent Document 6, a structure is used in which the magnetostrictive material and the magnetic material are separated into parallel beams in order to improve the power generation output. This structure allows the magnetic material to be used without magnetic saturation, and the magnetic flux of the magnetic material is changed by changing the magnetic flux of the magnetostrictive material, so that a voltage can be extracted that is the sum of the induced voltage by the magnetostrictive material and the induced voltage by the magnetic material. As magnetostrictive materials, FeGa, FeCo, FeNi, and FeDyTe are listed, and as magnetic materials, ferritic stainless steel, FeSi, NiFe, CoFe, SmCo, NdFeB, CoCr, and CoPt are listed.

International Publication No. 2018/230154 JP 2018-148791 A International Publication No. 2014/021197 International Publication No. 2013/038682 International Publication No. 2013/186876 JP 2015-70741 A

As is clear from the descriptions in Patent Documents 1 to 6, various magnetostrictive materials are used together with other materials in magnetostrictive power generation elements and magnetostrictive power generation devices. As a magnetostrictive material, Patent Documents 2 to 6 describe FeGa alloys, which are known to have the largest amount of magnetostriction. However, FeGa alloys are very expensive because they are manufactured by a single crystal pulling method (CZ method). The FeCo alloys described in Patent Documents 1 to 6 are manufactured by a rolling method, but they are also expensive because they contain Co. In addition, the FeAl alloys described in Patent Documents 1 and 2 are less expensive than the FeGa alloys and FeCo alloys, but are still expensive. In addition, they have low toughness, and are not easily manufactured into a plate shape by a normal rolling method.

In consideration of these problems, when manufacturing a magnetostrictive power generation device using the above-mentioned high-cost magnetostrictive material, a magnetostrictive element for power generation is manufactured consisting of a magnetostrictive material and a mating material to be bonded thereto, and the magnetostrictive element for power generation is fixed to a frame or the like manufactured from a lower-cost material. In a magnetostrictive power generation device in which a magnetostrictive element for power generation is fixed to a frame in this way, it is difficult to maintain sufficient joint strength between the magnetostrictive element for power generation and the frame, and durability may decrease. In addition, a magnetic gap may occur at the joint between the magnetostrictive element for power generation and the frame, and variations in the size of the gap cause variations in magnetic resistance, making it difficult to adjust the bias magnetic field applied to the magnetostrictive element for power generation to a constant value.

The present invention relates to the following magnetostrictive power generating device.
[1] A magnetostrictive power generation device comprising a magnetostrictive element for power generation having a magnetostrictive portion formed of an electromagnetic steel plate and a stress control portion formed of an elastic material, and a frame continuous with the magnetostrictive element for power generation, wherein at least a portion of the frame is composed of a laminate including the electromagnetic steel plate extending from the magnetostrictive portion and the elastic material extending from the stress control portion.
[2] The device according to [1], wherein the electrical steel sheet is a grain-oriented electrical steel sheet.
[3] The device according to [1], wherein the electrical steel sheet is a non-oriented electrical steel sheet.
[4] The device according to any one of [1] to [3], wherein the elastic material is a non-magnetic material.
[5] The device according to any one of [1] to [4], wherein the entire frame is integral with the electromagnetic steel plate extending from the magnetostrictive portion.
[6] The device according to any one of [1] to [4], wherein the entire frame is integral with the elastic material extending from the stress control section.
[7] The device according to any one of [1] to [4], wherein the entire frame is integral with the magnetostrictive element for power generation.
[8] The device described in any one of [1] to [7], wherein the frame has a shape having at least one curved portion, and in the frame and the magnetostrictive element for power generation, the electromagnetic steel plate is located inside the device, and the elastic material is located outside the device.
[9] The device described in any one of [1] to [7], wherein the frame has a shape having at least one curved portion, and in the frame and the magnetostrictive element for power generation, the elastic material is located inside the device, and the electromagnetic steel sheet is located outside the device.

According to the present invention, in a magnetostrictive power generation device including a magnetostrictive element having a magnetostrictive portion formed of electromagnetic steel plate and a stress control portion formed of an elastic material, and a frame continuous with the magnetostrictive element, by forming at least a portion of the frame from a laminate including electromagnetic steel plate extending from the magnetostrictive portion and an elastic material extending from the stress control portion, a magnetostrictive power generation device with stable performance is provided that is low-cost, has excellent durability, and can achieve a power generation amount equivalent to or exceeding that of conventional magnetostrictive power generation devices.

1 is a schematic diagram showing the structure of a magnetostrictive generating device of the present invention. FIG. 2 is another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 2 is a schematic diagram showing the structure of a magnetostrictive generating device of a comparative example. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention. FIG. 4 is yet another schematic diagram showing the structure of the magnetostrictive generating device of the present invention.

As mentioned above, the magnetostrictive materials described in the prior art as being for power generation are mainly materials with large saturation magnetostriction, such as FeGa alloys with a saturation magnetostriction of about 200 ppm, or FeCo alloys and FeAl alloys with a saturation magnetostriction of 80 ppm. This is because the larger the saturation magnetostriction, the larger the magnetoelastic energy generated when the magnetostrictive material is distorted, and the easier it is for the magnetization direction in the magnetostrictive material to change in order to reduce this energy. The easier it is for the magnetization direction to change, the larger the voltage induced in the detection coil. In other words, it has not been previously envisioned to use magnetic steel sheets (i.e., FeSi alloys) with a saturation magnetostriction of 8 ppm as magnetostrictive materials for power generation.

In this situation, the inventors formed the magnetostrictive portion of the magnetostrictive element for power generation from electromagnetic steel sheets, formed the stress control portion laminated thereon from an elastic material, and further constructed at least a part of the frame continuous with the magnetostrictive element of the magnetostrictive power generation device from a laminate including electromagnetic steel sheets extending from the magnetostrictive portion and elastic material extending from the stress control portion. In such a magnetostrictive power generation device, the joint between the magnetostrictive element for power generation and the frame is not present in the magnetostrictive element or in the vicinity of the magnetostrictive element, so that when continuous strain is applied to the magnetostrictive element for power generation, stress concentration is unlikely to occur at the joint, and the durability of the device is improved. Furthermore, the continuity within the members constituting the magnetic circuit is increased, so the occurrence of magnetic gaps is reduced, making it easier to adjust the bias magnetic field by magnets and stabilizing the voltage. In addition, because electromagnetic steel sheets are less expensive than conventional magnetostrictive materials such as FeGa alloys and FeCo alloys, it is possible to reduce the cost of the magnetostrictive power generation device while achieving a power generation amount equivalent to or exceeding that of conventional magnetostrictive power generation devices, and thus the present invention has been completed.

The present invention will be described below with reference to exemplary embodiments, but the present invention is not limited to the following embodiments.

The present invention relates to a magnetostrictive generating device. The magnetostrictive generating device of the present invention is a magnetostrictive generating device including a magnetostrictive element for generating electricity and a support portion.
In the present invention, a "magnetostrictive element for power generation" (hereinafter often abbreviated as "magnetostrictive element") refers to an element that includes a magnetostrictive portion formed from an electromagnetic steel sheet and a stress control portion formed from an elastic material, and that is capable of generating power based on the inverse magnetostriction of the magnetostrictive portion (i.e., the generation of a magnetic field associated with a change in shape (distortion) of the magnetostrictive portion). Structurally, it is an area that contributes to power generation, in which a detection coil is wound around a laminate including the magnetostrictive portion and the stress control portion. In an actual power generation device, the adjacent portion outside the area around which the coil is wound also contributes to power generation, but in this specification, the area around which the coil is wound is defined as the magnetostrictive power generation element.

The magnetostrictive portion in the magnetostrictive element for power generation of the present invention is formed from an electromagnetic steel sheet. In the present invention, "electromagnetic steel sheet" refers to a functional material, sometimes called "silicon steel sheet", in which silicon (Si) is added to iron (Fe) to improve the magnetic properties of iron. The electromagnetic steel sheet in the present invention is an electromagnetic steel sheet with a silicon content of 0.5% to 4%. An electromagnetic steel sheet with a silicon content of 0.5% to 4% is suitable for use in the magnetostrictive portion because the increase in electrical resistance due to the addition of silicon can suppress the generation of eddy currents that hinder magnetic domain changes during AC vibration.

Furthermore, there are directional electromagnetic steel sheets and non-directional electromagnetic steel sheets, and in the present invention, both directional electromagnetic steel sheets and non-directional electromagnetic steel sheets can be used for the magnetostrictive portion. A directional electromagnetic steel sheet is one in which the crystal orientation of the metal crystal is aligned in the rolling direction of the steel sheet. Specifically, it is an electromagnetic steel sheet with a {110}[100] GOSS texture in which the <100> direction is aligned in the rolling direction and the rolling surface is oriented in the (110) direction. On the other hand, a non-directional electromagnetic steel sheet is one in which the crystal orientation of the metal crystal is not aligned in a specific direction and has a relatively random crystal orientation. Both directional electromagnetic steel sheets and non-directional electromagnetic steel sheets are materials with a lower saturation magnetostriction than FeGa alloys and FeCo alloys, but they are capable of generating electricity equivalent to or exceeding that of conventional magnetostrictive materials. The reason for this is not clear, but is presumed to be as follows.

As described above, grain-oriented electrical steel sheets have a {110}[100] GOSS texture with the <100> direction aligned with the rolling direction and the rolling surface oriented in the (110) direction. The inventors have newly discovered that when a bias magnetic field is applied to the grain-oriented electrical steel sheet in the [100] direction and compressive strain is applied, the magnetic flux density of the grain-oriented electrical steel sheet changes significantly. This is thought to be because when a certain magnetic field is applied to the [100] direction of the grain-oriented electrical steel sheet, the ratio of 180° magnetic domains and 90° magnetic domains parallel to the [100] direction becomes a ratio in which the two interact well, and when strain is applied to the grain-oriented electrical steel sheet, the 180° magnetic domains are easily converted to 90° magnetic domains, or the 90° magnetic domains are easily converted to 180° magnetic domains. Specifically, when compressive strain is applied parallel to the magnetization direction of the 180° magnetic domain (i.e., the [100] direction), the 180° magnetic domain decreases and the 90° magnetic domain increases, and when tensile strain is applied in the [100] direction, the 90° magnetic domain decreases and the 180° magnetic domain increases. When compressive strain is applied perpendicular to the magnetization direction of the 180° magnetic domain (i.e., the [110] direction), the 90° magnetic domain decreases and the 180° magnetic domain increases, and when tensile strain is applied in the [110] direction, the 180° magnetic domain decreases and the 90° magnetic domain increases. These changes in magnetic domains change the magnetization of the directional magnetic steel sheet, which functions as the magnetostrictive portion of the magnetostrictive element. In the magnetostrictive power generation device, the above-mentioned change in magnetization induces a voltage in the detection coil wound around the magnetostrictive element.

In addition, while non-oriented electrical steel sheets do not have the same crystal orientation as oriented electrical steel sheets, they found that when strain is applied with a bias magnetic field applied, the magnetic flux density changes significantly. In non-oriented electrical steel sheets, the crystal orientation is relatively random, so the magnetic domains are smaller than in oriented electrical steel sheets. As a result, when strain is applied, the magnetic domains that are easiest to move among the many magnetic domains will move first, and it is believed that a large change in magnetic flux density can be obtained when used as the magnetostrictive part of a magnetostrictive element.

In the present invention, grain-oriented electromagnetic steel sheets are more likely to induce a larger change in magnetization than non-oriented electromagnetic steel sheets, so grain-oriented electromagnetic steel sheets are preferred as magnetostrictive portions.

Specific examples of oriented electrical steel sheets include Nippon Steel Corporation's Orient Core, Orient Core Hi-B (e.g., 27ZH100), Orient Core Hi-B Laser, and Orient Core Hi-B Permanent.

Specific examples of non-oriented electrical steel sheets include Nippon Steel's Highlight Core (e.g., 35H210) and Home Core.

The magnetostrictive element for power generation further has a stress control section formed from an elastic material. The "stress control section" in a magnetostrictive element is a section for controlling stress in order to achieve either a compressive or tensile stress load on the entire magnetostrictive section when bending strain, etc. is applied to the magnetostrictive element. There are no particular limitations on the material forming the stress control section as long as it is an elastic material that can achieve the above purpose, and both non-magnetic and magnetic materials can be used.

When the elastic material forming the stress control section is a non-magnetic material, the magnetic field flows preferentially only through the magnetostrictive section of the magnetostrictive element section (the section corresponding to the magnetostrictive element), which makes it easy to adjust the bias magnetic field of the magnetostrictive section. Furthermore, the inventors have found that when bending strain is applied to a magnetostrictive element in which the magnetostrictive section is formed of a directional electromagnetic steel sheet and the stress control section is formed of a non-magnetic material, a larger change in magnetic flux density occurs compared to other combinations. This is because, when a magnetic material is used as the elastic material, a magnetic interaction occurs between the elastic material and the electromagnetic steel sheet, which can prevent the conversion of the 90° magnetic domain and the 180° magnetic domain. However, when the elastic material is a non-magnetic material, such a magnetic interaction does not occur, making it easier for the 90° magnetic domain and the 180° magnetic domain of the electromagnetic steel sheet to be converted.

Examples of elastic materials that are non-magnetic materials that form the stress control section include, but are not limited to, fiber reinforced plastics (e.g., CFRP, GFRP), austenitic stainless steel (e.g., SUS304, SUS316, etc.), copper alloys (e.g., brass, phosphor bronze), aluminum alloys (e.g., duralumin), titanium alloys (e.g., Ti-6Al-4V), etc. Among these, fiber reinforced plastics and austenitic stainless steel are preferred because they have a relatively high Young's modulus and it is easy to position the neutral plane outside the magnetostrictive section when bending strain is applied.

Forming the stress control section from a magnetic material, which is an elastic material, is effective in reducing costs. When the magnetostrictive section of the magnetostrictive element is a directional electromagnetic steel sheet or a non-directional electromagnetic steel sheet, and the elastic material forming the stress control section is a steel sheet that is a magnetic material, when a bias magnetic field is applied, a bias magnetic field flows through both the magnetostrictive section and the stress control section. However, since the directional electromagnetic steel sheet or non-directional electromagnetic steel sheet forming the magnetostrictive section is originally a high magnetic permeability material, it is thought that a large bias magnetic field flows through the magnetostrictive section, and therefore a magnetic domain change sufficient for power generation occurs. However, compared to when the stress control section is made of a non-magnetic material, the magnetic force applied to the magnetostrictive section is reduced by the amount of magnetic flux flowing through the stress control section formed of a magnetic material. In order to compensate for this reduction in magnetic force, the strength of the magnet equipped in the magnetostrictive power generation device can be increased.

Examples of elastic materials that are magnetic materials and form the stress control section include, but are not limited to, general structural rolled steel (e.g., SS400), general structural carbon steel (e.g., S45C), high tensile steel (e.g., HT80), ferritic stainless steel (e.g., SUS430), and martensitic stainless steel (e.g., SUS410).

In the magnetostrictive element, the stress control section and the magnetostrictive section are bonded together to form a laminate. There are no particular limitations on the method for bonding the stress control section and the magnetostrictive section, but typical methods include bonding with an adhesive or adhesive sheet between them, brazing material bonding, and liquid phase diffusion bonding.

The magnetostrictive generating device of the present invention further comprises a frame continuous with the magnetostrictive element. In the present invention, the "frame" of the magnetostrictive generating device is a part that is joined to the magnetostrictive element, weight, and magnet, respectively, to form the main body of the magnetostrictive generating device. Furthermore, in the present invention, the frame is continuous with the magnetostrictive element, and at least a part of the frame is composed of a laminate including an electromagnetic steel plate extending from the magnetostrictive part of the magnetostrictive element and an elastic material extending from the stress control part of the magnetostrictive element. This means that at least the part of the frame adjacent to the magnetostrictive element (the part near the coil where the coil is not wound) is integral with the magnetostrictive element, and it is not necessary that the entire frame is integral with the magnetostrictive element.

In the frame of the magnetostrictive power generation device, there is an area consisting of a laminate including an electromagnetic steel sheet extending from the magnetostrictive portion and an elastic material extending from the stress control portion from each end of the magnetostrictive element (so as to extend beyond the coil). The length of this area is 50% or more of the length corresponding to the length of the coil, and preferably, is equal to or greater than the length of the coil. In such a magnetostrictive power generation device, since the joint between the magnetostrictive element for power generation and the frame is not present in the magnetostrictive element or in the vicinity of the magnetostrictive element, stress concentration is unlikely to occur at the joint when continuous bending strain is applied to the magnetostrictive element for power generation, and the durability of the device is improved. In addition, it is preferable that the laminate including the electromagnetic steel sheet and the elastic material extending from the magnetostrictive element extends to the joint position of the weight for applying bending strain to the magnetostrictive portion, because the bending strain caused by the vibration of the weight is efficiently transmitted to the magnetostrictive element portion.

Furthermore, the portion of the frame that is composed of a laminate including an electromagnetic steel plate extending from the magnetostrictive portion and an elastic material extending from the stress control portion is preferably 20% or more of the overall length of the frame, and more preferably 40% or more. By having 20% or more of the overall length of the frame composed of the above-mentioned laminate, it is possible to expand the adhesive surface between the magnetostrictive portion formed of the electromagnetic steel plate and the stress control portion formed of the elastic material. As a result, the continuity within the members that make up the magnetic circuit is increased, the occurrence of magnetic gaps is reduced, and it becomes easier to adjust the bias magnetic field by the magnet, and the voltage can be stabilized.

When only a part of the frame is composed of a laminate including an electromagnetic steel plate extending from the magnetostrictive portion and an elastic material extending from the stress control portion, there is no particular limitation on the material of the remaining part of the frame, and the frame can be completed by joining other steel plates, elastic materials, etc. However, from the viewpoint of the durability of the device and ease of manufacturing, it is preferable that the entire frame is integrally composed with the electromagnetic steel plate extending from the magnetostrictive portion and/or the elastic material extending from the stress control portion. Specifically, a structure in which the electromagnetic steel plate forming the magnetostrictive portion is present in the part corresponding to the magnetostrictive element and the entire frame, and an elastic material forming the stress control portion is laminated on a part of the frame and a part corresponding to the magnetostrictive element, or a structure in which the elastic material forming the stress control portion is present in the part corresponding to the magnetostrictive element and the entire frame, and an electromagnetic steel plate forming the magnetostrictive portion is laminated on a part of the frame and a part corresponding to the magnetostrictive element, is preferable. In such a structure in which the electromagnetic steel plate or elastic material constituting the magnetostrictive element extends over the entire frame, both the magnetostrictive element and the frame can be manufactured by preparing a laminate including the electromagnetic steel plate and the elastic material. This makes it possible to simplify the manufacturing process. In addition, at least a portion of the electromagnetic steel plate and elastic material that make up the magnetostrictive element extends to the fixing portion for fixing the magnetostrictive power generation device to a vibration source, etc., which is particularly preferable because it allows vibrations from the vibration source, etc. to be efficiently transmitted to the magnetostrictive element portion.

The entire frame may also be composed of a laminate including electromagnetic steel plates extending from the magnetostrictive section and elastic material extending from the stress control section. In such a configuration, the laminate including the electromagnetic steel plates and elastic material continuously forms both the magnetostrictive element and the frame, and there is no joint between the magnetostrictive element and the frame, which is preferable from the standpoint of durability. Furthermore, since the continuity within the members that make up the magnetic circuit is increased, the occurrence of magnetic gaps is reduced, making it easier to adjust the bias magnetic field by the magnet, and further stabilizing the voltage.

There are no particular limitations on the dimensions of the frame containing the magnetostrictive element, but the length of the frame containing the magnetostrictive element is generally 30 mm to 700 mm, preferably 60 mm to 500 mm, and more preferably 120 mm to 300 mm. The width of the frame is generally 4 mm to 70 mm, preferably 6 mm to 50 mm, and more preferably 8 mm to 30 mm. The frame dimensions can be reflected in the design according to the amount of power required to operate the device.

The shape of the frame is not particularly limited, and it can be a plate-like, C-shaped, U-shaped, V-shaped, or other shape with at least one curved portion. In the present invention, since a highly tough electromagnetic steel sheet is used for the magnetostrictive portion, it is possible to manufacture not only plate-like frames, but also frames with curved portions such as U-shaped frames, from the magnetostrictive material that forms the magnetostrictive portion.

When the frame has a shape with at least one curved portion (e.g., U-shaped), the frame and magnetostrictive element may be configured such that the electromagnetic steel sheet is located inside the device and the elastic material is located outside the device, or the elastic material is located inside the device and the electromagnetic steel sheet is located outside the device. For example, in a U-shaped frame, if the electromagnetic steel sheet is located inside the device and the elastic material is located outside the device, it becomes possible to place the magnet directly on the electromagnetic steel sheet (i.e., the magnetostrictive material). As a result, the magnetic gap is reduced, making it easier to adjust the bias magnetic field.

In addition, in a device having a frame with at least one curved portion, such as a U-shape, when the weight vibrates, a large stress may be applied to the curved portion of the U-shape, and at that portion, a compressive stress acts on the material located inside the U-shape, and a force acts to peel the material located inside from the material located outside. In a configuration in which the electromagnetic steel sheet is located on the outside of the device and the elastic material is located on the inside of the device, it is possible to use a relatively strong elastic material for the stress control section, so that the inner stress control section can receive the compressive stress and make it difficult for peeling to occur with the electromagnetic steel sheet. Furthermore, in a device with such a configuration, when a tensile strain acts on the electromagnetic steel sheet and the magnetic flux density increases due to the effect of magnetostriction, the electromagnetic steel sheet approaches the magnet, and as a result, the magnetic flux density of the electromagnetic steel sheet changes to increase. In addition to the change in magnetic flux density due to magnetostriction, the change in magnetic flux density due to the magnetic field of the magnet is added, so the power generation output increases.

The larger the dimensions of the magnetostrictive element for power generation in the magnetostrictive power generation device of the present invention, the more the number of turns of the coil can be increased in the power generation device, and a higher voltage can be obtained. Therefore, there is no particular limit to the dimensions of the magnetostrictive element (the length of the area around which the coil is wound), but it is usually 5 mm or more and 150 mm or less, preferably 10 mm or more and 100 mm or less, and more preferably 20 mm or more and 70 mm or less.

There is no particular limit to the thickness of the electromagnetic steel sheet that forms the magnetostrictive portion and frame of the magnetostrictive element, but it is usually 0.2 mm or more and 0.5 mm or less. If the thickness of the magnetostrictive portion is 0.2 mm or more, it is advantageous because the change in magnetic flux can be made larger and the generated voltage can be made larger, and if it is 0.5 mm or less, it is advantageous because it is easier to design the rigidity suitable for vibration. The thickness of the electromagnetic steel sheet may be the same or different between the magnetostrictive portion in the magnetostrictive element and the laminate that forms the frame.

There is no particular limit to the thickness of the elastic material forming the stress control section and frame of the magnetostrictive element, but it is usually 0.1 mm to 2.0 mm, preferably 0.2 mm to 1.0 mm, and more preferably 0.2 mm to 0.5 mm. If the thickness of the stress control section is 0.1 mm or more, it is advantageous to achieve either a compressive or tensile stress load on the entire magnetostrictive section, and if it is 2.0 mm or less, it is possible to suppress interference with the vibration of the magnetostrictive element. The thickness of the elastic material may be the same in the magnetostrictive section in the magnetostrictive element and in the laminate that constitutes the frame, or it may be different.

As long as the magnetostrictive generating device of the present invention has the specific magnetostrictive generating element and the specific frame described above, there are no particular limitations on the other configurations, and it can be configured in the same way as a conventional magnetostrictive generating device. Specifically, in this device, a coil is loaded around the magnetostrictive element, and the device includes a frame, a weight attached to the frame, and a magnet. In such a device, the magnetic field lines of the magnet pass through the magnetostrictive element and apply a bias magnetic field to the magnetostrictive part. The frame then vibrates due to the vibration of the weight, applying tensile and compressive forces to the magnetostrictive element. At this time, the direction in which bending distortion is applied to the magnetostrictive part and the direction in which a bias magnetic field is applied to the magnetostrictive part are parallel, and the magnetization of the magnetostrictive element can be changed by the inverse magnetostrictive effect, generating an induced current (or induced voltage) in the coil.

When the magnetostrictive portion is formed from a grain-oriented electromagnetic steel sheet, it is preferable to configure the device so that a bias magnetic field is applied in the [100] direction of the grain-oriented electromagnetic steel sheet, since this allows a larger voltage to be obtained.

There are no particular limitations on the size or number of magnets in a magnetostrictive power generation device, and they can be selected according to the configuration of the device. It is preferable to use a permanent magnet to generate the bias magnetic field. This is because permanent magnets can be made small and the bias magnetic field is easy to control. In addition, NdFeB magnets are preferable as permanent magnets because they can generate a larger bias magnetic field.

Next, the basic configuration of the magnetostrictive power generation device of the present invention will be described with reference to the device of the embodiment shown in the drawings, but the device of the present invention is not limited to these. Note that Figures 1 to 5, 7 and 8 show devices in which an electromagnetic steel sheet is located on the inside of a frame having a curved portion and an elastic material is located on the outside, and Figures 10 to 19 show devices in which an elastic material is located on the inside of a frame having a curved portion and an electromagnetic steel sheet is located on the outside.

Figure 1 is a schematic diagram of a magnetostrictive generating device 100 in which the entire U-shaped frame is integrated with the magnetostrictive element. In the magnetostrictive generating device 100, the magnetostrictive element 110 has a magnetostrictive portion 111 and a stress control portion 112, and a detection coil 160 is mounted around them. In this device, the electromagnetic steel plate 121 in the laminate 120 constituting the frame 130 is arranged on the inside of the device, and the elastic material 122 is arranged on the outside (in the magnetostrictive element 110, the magnetostrictive portion 111 is arranged on the inside, and the stress control portion 112 is arranged on the outside). The thicknesses of the electromagnetic steel plate 121 and the elastic material 122 are the same as those of the magnetostrictive portion 111 and the stress control portion 112, respectively. In addition, it has a weight 140 for applying bending strain to the magnetostrictive portion and a magnet 150 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing portion 170.

The magnetostrictive power generation device can be fixed using adhesive or bolts. When fixing with bolts, for example, a bolt hole can be provided in the area to the right of the magnet 150, and the device can be fixed to the vibration source with a bolt. (The same applies to devices with other configurations below.)

Figure 2 is a schematic diagram of a magnetostrictive generating device 200 in which the entire U-shaped frame is integral with the magnetostrictive element. In the magnetostrictive generating device 200, the magnetostrictive element 210 has a magnetostrictive portion 211 and a stress control portion 212, and a detection coil 260 is mounted around them. In this device, the electromagnetic steel plate 221 in the laminate 220 constituting the frame 230 is arranged on the inside of the device, and the elastic material 222 is arranged on the outside (in the magnetostrictive element 210, the magnetostrictive portion 211 is arranged on the inside and the stress control portion 212 is arranged on the outside). In addition, the electromagnetic steel plate 221 and the magnetostrictive portion 211 have the same thickness, but the thickness of the stress control portion 212 is made thinner than the thickness of the elastic material 222 in the laminate 220, making it easier to vibrate the magnetostrictive element. The device 200 further has a weight 240 for applying bending strain to the magnetostrictive portion and a magnet 250 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing portion 270.

Figure 3 is a schematic diagram of a magnetostrictive generating device 300 in which the entire U-shaped frame is integral with the elastic material extending from the stress control section. In the magnetostrictive generating device 300, the magnetostrictive element 310 has a magnetostrictive section 311 and a stress control section 312, and a detection coil 360 is mounted around it. In this device, the entire frame 330 is integral with the elastic material 322 extending from the stress control section 312, and a part (about 70%) of the frame is composed of a laminate 320 including an electromagnetic steel sheet 321 and an elastic material 322. In the part composed of the laminate 320, the electromagnetic steel sheet 321 is arranged inside the device and the elastic material 322 is arranged outside (in the magnetostrictive element 310, the magnetostrictive section 311 is arranged inside and the stress control section 312 is arranged outside). The device 300 further has a weight 340 for applying a distortion to the magnetostrictive section and a magnet 350 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing section 370.

Figure 4 is a schematic diagram of a magnetostrictive generating device 400 in which the entire U-shaped frame is integral with the elastic material extending from the stress control section. In the magnetostrictive generating device 400, the magnetostrictive element 410 has a magnetostrictive section 411 and a stress control section 412, and a detection coil 460 is mounted around it. The entire frame 430 is integral with the elastic material 422 extending from the stress control section 412, and a part (about 70%) of the frame is composed of a laminate 420 including an electromagnetic steel sheet 421 and an elastic material 422. In the part composed of the laminate 420, the electromagnetic steel sheet 421 is arranged inside the device and the elastic material 422 is arranged outside (in the magnetostrictive element 410, the magnetostrictive section 411 is arranged inside and the stress control section 412 is arranged outside). The device 400 further has a weight 440 for applying a distortion to the magnetostrictive section and a magnet 450 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing section 470. In this device, the elastic material 422 that forms the stress control section 412 is a magnetic material, so a magnetic field flows not only through the magnetostrictive section 411 but also through the stress control section, which is made of a magnetic material, so a large magnet is used as the magnet 450.

Figure 5 is a schematic diagram of a magnetostrictive generating device 500 in which the entire U-shaped frame is integral with the elastic material extending from the stress control section. In the magnetostrictive generating device 500, the magnetostrictive element 510 has a magnetostrictive section 511 and a stress control section 512, and a detection coil 560 is mounted around it. The entire frame 530 is integral with the elastic material 522 extending from the stress control section 512, and a part (about 50%) of the frame is composed of a laminate 520 including an electromagnetic steel sheet 521 and an elastic material 522. In the part composed of the laminate 520, the electromagnetic steel sheet 521 is arranged inside the device and the elastic material 522 is arranged outside (in the magnetostrictive element 510, the magnetostrictive section 511 is arranged inside and the stress control section 512 is arranged outside). The device 500 further has a weight 540 for applying bending strain to the magnetostrictive section and a magnet 550 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing section 570. In this device, the area made up of the laminate 520 is shorter than the similar area in FIG. 4, and two small magnets are used as the magnet 550.

Figure 6 is a schematic diagram of a magnetostrictive generating device 600 in which the entire plate-like frame is integral with the magnetostrictive element. In the magnetostrictive generating device 600, the magnetostrictive element 610 has a magnetostrictive portion 611 and a stress control portion 612, and a detection coil 660 is mounted around them. In this device, the frame 630 is composed of a laminate 620 including an electromagnetic steel plate 621 and an elastic material 622. It further has a weight 640 for applying bending strain to the magnetostrictive portion and a magnet 650 for applying a bias magnetic field, and can be fixed to a vibration source by a fixing portion 670.

Figure 7 is a schematic diagram of a magnetostrictive generating device 700 in which the entire U-shaped frame is integral with an electromagnetic steel plate extending from the magnetostrictive portion. In the magnetostrictive generating device 700, the magnetostrictive element 710 has a magnetostrictive portion 711 and a stress control portion 712, and a detection coil 760 is mounted around it. The entire frame 730 is integral with an electromagnetic steel plate 721 extending from the magnetostrictive portion 711, and a part of the frame (about 27%) is composed of a laminate 720 including an electromagnetic steel plate 721 and an elastic material 722. In the part composed of the laminate 720, the electromagnetic steel plate 721 is arranged inside the device and the elastic material 722 is arranged outside (in the magnetostrictive element 710, the magnetostrictive portion 711 is arranged inside and the stress control portion 712 is arranged outside). The device 700 further has a weight 740 for applying a bending strain to the magnetostrictive portion and a magnet 750 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing portion 770. This device has a structure in which the elastic material 722 is shortened and a support 780 is inserted into the U-shaped section to facilitate vibration of the magnetostrictive element in the detection coil.

Figure 8 is a schematic diagram of a magnetostrictive generating device 800 in which the entire U-shaped frame is integral with an electromagnetic steel plate extending from the magnetostrictive portion. In the magnetostrictive generating device 800, the magnetostrictive element 810 has a magnetostrictive portion 811 and a stress control portion 812, and a detection coil 860 is mounted around it. The entire frame 830 is integral with an electromagnetic steel plate 821 extending from the magnetostrictive portion 811, and only a part of the frame is composed of a laminate 820 including an electromagnetic steel plate 821 and an elastic material 822. In the part composed of the laminate 820, the electromagnetic steel plate 821 is arranged inside the device and the elastic material 822 is arranged outside (in the magnetostrictive element 810, the magnetostrictive portion 811 is arranged inside and the stress control portion 812 is arranged outside). The device 800 further has a weight 840 for applying a bending strain to the magnetostrictive portion and a magnet 850 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing portion 870. This device has a structure in which the elastic material 822 is shortened and a support 880 is inserted into the U-shaped section to facilitate vibration of the magnetostrictive element in the detection coil, and two small magnets are used as the magnet 850.

Figures 10 and 11 are schematic diagrams of magnetostrictive generating devices 1000 and 1100, respectively, in which the entire U-shaped frame is integral with the magnetostrictive element. In the magnetostrictive generating device 1000, the magnetostrictive element 1010 has a magnetostrictive portion 1011 and a stress control portion 1012, and a detection coil 1060 is mounted around them. In this device, the electromagnetic steel plate 1021 of the laminate 1020 constituting the frame 1030 is arranged on the outside, and the elastic material 1022 is arranged on the inside (in the magnetostrictive element 1010, the magnetostrictive portion 1011 is arranged on the outside, and the stress control portion 1012 is arranged on the inside). The device 1000 further has a weight 1040 for applying bending strain to the magnetostrictive portion and a magnet 1050 for applying a bias magnetic field, and can be fixed on a vibration source by a fixing portion 1070.

The magnetostrictive generating device 1100 has substantially the same structure as the magnetostrictive generating device 1000 of FIG. 10, except that a support 1180 is provided. Specifically, the magnetostrictive element 1110 has a magnetostrictive portion 1111 and a stress control portion 1112, and a detection coil 1160 is mounted around them. In this device, the electromagnetic steel plate 1121 of the laminate 1120 constituting the frame 1130 is arranged on the outside, and the elastic material 1122 is arranged on the inside (in the magnetostrictive element 1110, the magnetostrictive portion 1111 is arranged on the outside, and the stress control portion 1112 is arranged on the inside). The device 1100 further has a weight 1140 for applying bending strain to the magnetostrictive portion and a magnet 1150 for applying a bias magnetic field. Furthermore, the device has a support 1180 provided on the U-shaped portion of the frame 1130 to facilitate vibration of the magnetostrictive element 1110 in the detection coil 1160. The device can be fixed on a vibration source by a fixing portion 1170.

12 and 13 are schematic diagrams of magnetostrictive generating devices 1200 and 1300, respectively, in which the entire frame having one U-shaped portion and one L-shaped portion is integrally formed with the magnetostrictive element. In the magnetostrictive generating device 1200, the magnetostrictive element 1210 has a magnetostrictive portion 1211 and a stress control portion 1212, and a detection coil 1260 is mounted around them. In this device, the electromagnetic steel sheet 1221 of the laminate 1220 constituting the frame 1230 is arranged on the outside, and the elastic material 1222 is arranged on the inside (in the magnetostrictive element 1210, the magnetostrictive portion 1211 is arranged on the outside, and the stress control portion 1212 is arranged on the inside). The device 1200 further has a weight 1240 for applying bending strain to the magnetostrictive portion and a magnet 1250 for applying a bias magnetic field, and the magnet 1250 is fixed to the inside (elastic material 1222 side) of the tip portion at the end of the portion bent into an L shape. Furthermore, the device can be fixed above the vibration source with the fixing portion 1270.

The magnetostrictive generating device 1300 has substantially the same structure as the magnetostrictive generating device 1200 in FIG. 12, except that a support 1380 is provided. Specifically, the magnetostrictive element 1310 has a magnetostrictive portion 1311 and a stress control portion 1312, and a detection coil 1360 is mounted around them. In this device, the electromagnetic steel plate 1321 of the laminate 1320 constituting the frame 1330 is arranged on the outside, and the elastic material 1322 is arranged on the inside (in the magnetostrictive element 1310, the magnetostrictive portion 1311 is arranged on the outside, and the stress control portion 1312 is arranged on the inside). The device 1300 further has a weight 1340 for applying bending strain to the magnetostrictive portion and a magnet 1350 for applying a bias magnetic field, and the magnet 1350 is fixed to the inside (elastic material 1322 side) of the tip portion at the end of the portion bent into an L shape. Furthermore, the device is provided with a support 1380 at the U-shaped portion of the frame 1330 to facilitate vibration of the magnetostrictive element 1310 in the detection coil 1360. The device can be fixed onto a vibration source with a fixing portion 1370.

14 and 15 are schematic diagrams of magnetostrictive generating devices 1400 and 1500, respectively, in which a frame having one U-shaped portion and one L-shaped portion is integral with the magnetostrictive element, and no elastic material exists in the portion where the magnet is fixed. In the magnetostrictive generating device 1400, the magnetostrictive element 1410 has a magnetostrictive portion 1411 and a stress control portion 1412, and a detection coil 1460 is mounted around them. In this device, the electromagnetic steel plate 1421 of the laminate 1420 constituting the frame 1430 is arranged on the outside, and the elastic material 1422 is arranged on the inside (in the magnetostrictive element 1410, the magnetostrictive portion 1411 is arranged on the outside, and the stress control portion 1412 is arranged on the inside). The device 1400 further has a weight 1440 for applying a bending strain to the magnetostrictive portion and a magnet 1450 for applying a bias magnetic field, and the magnet 1450 is fixed to the inside of the electromagnetic steel plate 1421 at the tip portion of the portion bent into an L shape. In device 1400, there is no elastic material between the magnet and the electromagnetic steel plate, and the effect of the magnetic gap is small, making it possible to use a small-sized magnet. Furthermore, the device can be fixed onto a vibration source by fixing part 1470.

The magnetostrictive power generation device 1500 has substantially the same structure as the magnetostrictive power generation device 1400 in FIG. 14, except that a support 1580 is provided. Specifically, the magnetostrictive element 1510 has a magnetostrictive portion 1511 and a stress control portion 1512, and a detection coil 1560 is mounted around them. In this device, the electromagnetic steel sheet 1521 of the laminate 1520 constituting the frame 1530 is arranged on the outside, and the elastic material 1522 is arranged on the inside (in the magnetostrictive element 1510, the magnetostrictive portion 1511 is arranged on the outside, and the stress control portion 1512 is arranged on the inside). The device 1500 further has a weight 1540 for applying bending strain to the magnetostrictive portion and a magnet 1550 for applying a bias magnetic field, and the magnet 1550 is fixed to the inside of the electromagnetic steel sheet 1521 at the tip portion of the portion bent into an L shape. In the device 1500, there is no elastic material between the magnet and the electromagnetic steel sheet, and the effect of the magnetic gap is reduced, making it possible to use a magnet of a small size. Furthermore, the device is provided with a support 1580 at the U-shaped portion of the frame 1530 to facilitate vibration of the magnetostrictive element 1510 in the detection coil 1560. The device can be fixed onto a vibration source with a fixing portion 1570.

16 and 17 are schematic diagrams of magnetostrictive generating devices 1600 and 1700, respectively, in which the entire frame having one U-shaped portion and two L-shaped portions is integrally formed with the magnetostrictive element. In the magnetostrictive generating device 1600, the magnetostrictive element 1610 has a magnetostrictive portion 1611 and a stress control portion 1612, and a detection coil 1660 is mounted around them. In this device, the electromagnetic steel plate 1621 of the laminate 1620 constituting the frame 1630 is arranged on the outside, and the elastic material 1622 is arranged on the inside (in the magnetostrictive element 1610, the magnetostrictive portion 1611 is arranged on the outside, and the stress control portion 1612 is arranged on the inside). The device 1600 further has a weight 1640 for applying bending strain to the magnetostrictive portion and a magnet 1650 for applying a bias magnetic field, and the magnet 1650 is fixed to the upper elastic material 1622 of the L-shaped portion near the end. In device 1600, magnet 1650 and magnetostrictive portion 1611 can be brought close to each other to narrow the magnetic gap, making it possible to use a small magnet. Furthermore, the device can be fixed onto a vibration source by fixing portion 1670.

The magnetostrictive generating device 1700 has substantially the same structure as the magnetostrictive generating device 1600 of FIG. 16, except that a support 1780 is provided. Specifically, the magnetostrictive element 1710 has a magnetostrictive portion 1711 and a stress control portion 1712, and a detection coil 1760 is mounted around them. In this device, the electromagnetic steel plate 1721 of the laminate 1720 constituting the frame 1730 is arranged on the outside, and the elastic material 1722 is arranged on the inside (in the magnetostrictive element 1710, the magnetostrictive portion 1711 is arranged on the outside, and the stress control portion 1712 is arranged on the inside). The device 1700 further has a weight 1740 for applying bending strain to the magnetostrictive portion and a magnet 1750 for applying a bias magnetic field, and the magnet 1750 is fixed to the upper elastic material 1722 of the L-shape near the end. In the device 1700, the magnet 1750 and the magnetostrictive portion 1711 can be brought close to each other to narrow the magnetic gap, making it possible to use a magnet of a small size. Furthermore, the device is provided with a support 1780 at the U-shaped portion of the frame 1730 to facilitate vibration of the magnetostrictive element 1710 in the detection coil 1760. The device can be fixed onto a vibration source with a fixing portion 1770.

18 and 19 are schematic diagrams of magnetostrictive generating devices 1800 and 1900, respectively, in which a frame having one U-shaped portion and two L-shaped portions is integral with the magnetostrictive element, and no elastic material exists in the portion where the magnet is fixed. In the magnetostrictive generating device 1800, the magnetostrictive element 1810 has a magnetostrictive portion 1811 and a stress control portion 1812, and a detection coil 1860 is loaded around them. In this device, the electromagnetic steel plate 1821 of the laminate 1820 constituting the frame 1830 is arranged on the outside, and the elastic material 1822 is arranged on the inside (in the magnetostrictive element 1810, the magnetostrictive portion 1811 is arranged on the outside, and the stress control portion 1812 is arranged on the inside). The device 1800 further has a weight 1840 for applying bending strain to the magnetostrictive portion and a magnet 1850 for applying a bias magnetic field, and the magnet 1850 is fixed on the upper electromagnetic steel plate 1821 of the L-shaped portion near the end. In device 1800, the distance between magnet 1850 and magnetostrictive portion 1811 is short, and there is no elastic material between the magnet and the electromagnetic steel plate, so the effect of the magnetic gap is further reduced, making it possible to use a smaller magnet. Furthermore, the device can be fixed onto the vibration source by fixing portion 1870.

The magnetostrictive generating device 1900 has substantially the same structure as the magnetostrictive generating device 1800 of FIG. 18, except that a support 1980 is provided. Specifically, the magnetostrictive element 1910 has a magnetostrictive portion 1911 and a stress control portion 1912, and a detection coil 1960 is mounted around them. In this device, the electromagnetic steel plate 1921 of the laminate 1920 constituting the frame 1930 is arranged on the outside, and the elastic material 1922 is arranged on the inside (in the magnetostrictive element 1910, the magnetostrictive portion 1911 is arranged on the outside, and the stress control portion 1912 is arranged on the inside). The device 1900 further has a weight 1940 for applying bending strain to the magnetostrictive portion and a magnet 1950 for applying a bias magnetic field, and the magnet 1950 is fixed on the upper electromagnetic steel plate 1921 of the L-shape near the end. In device 1900, the distance between magnet 1950 and magnetostrictive portion 1911 is short, and there is no elastic material between the magnet and the electromagnetic steel plate, so the effect of the magnetic gap is further reduced, making it possible to use a smaller magnet. Furthermore, the device is provided with a support 1980 at the U-shaped portion of frame 1930 to facilitate vibration of magnetostrictive element 1910 in detection coil 1960. The device can be fixed onto a vibration source with fixing portion 1970.

The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these.

(Evaluation Method)
In the examples and comparative examples, the AC voltage induced in the detection coil of the magnetostrictive generating device was captured by a digital oscilloscope and the voltage was measured. The performance of the magnetostrictive generating device was evaluated based on the peak voltage of the measured voltage waveform.

Example 1
In Example 1, a directional electromagnetic steel sheet and a non-directional electromagnetic steel sheet were used as the electromagnetic steel sheet 121 (magnetostrictive material), and CFRP, which is a non-magnetic material, was used as the elastic material 122 to produce a magnetostrictive power generation device 100 having the structure shown in Figure 1.

As the grain-oriented electrical steel sheet, grain-oriented electrical steel sheet 27ZH100 with coating manufactured by Nippon Steel Corporation was used. The thickness was 0.27 mm, and the crystal orientation was {110}[100] GOSS texture. The grain-oriented electrical steel sheet was cut by shearing to a length of 140 mm and a width of 6 mm with the longitudinal direction of the grain-oriented electrical steel sheet set to the [100] direction. The sheet was then bent into a U-shape as shown in FIG. 1 to adjust the shape. The length corresponding to the lower fixing part 170 was about 80 mm, and the length of the part where the upper detection coil 160 and weight 140 were attached was about 40 mm.
After bending the grain-oriented electrical steel sheet into a U-shape, the sheet was annealed in a vacuum at 800° C. for 2 hours to remove distortion.

As the non-oriented electrical steel sheet, a non-oriented electrical steel sheet 35H210 with coating manufactured by Nippon Steel Corporation was used. The thickness was 0.35 mm. The non-oriented electrical steel sheet was sheared to a length of 140 mm and a width of 6 mm. The sheet was bent into a U-shape as shown in FIG. 1 to adjust the shape. The length corresponding to the lower fixing part 120 was about 80 mm, and the length of the part where the upper detection coil 160 and weight 140 were attached was about 40 mm.
After bending the non-oriented electrical steel sheet into a U-shape, the sheet was annealed in a vacuum at 740° C. for 2 hours to remove distortion.

The elastic material 122 was made of non-magnetic CFRP with a thickness of 0.5 mm and a width of 6 mm. The carbon fibers were cut to a length slightly longer than 140 mm so that they could be integrated with the U-shaped electromagnetic steel plate, and the material was then heat pressed to form a U-shape.

A U-shaped directional or non-directional electromagnetic steel sheet 121 and a U-shaped CFRP (elastic material 122) were bonded together at room temperature using an epoxy adhesive to form a laminate 120, and an integrated structure was obtained of the magnetostrictive element portion corresponding to the magnetostrictive element 110 and the entire frame 130 (i.e., 100%). A 5,000-turn detection coil 160 was loaded into the part of the integrated structure corresponding to the magnetostrictive element. The length of the coil was 15 mm. Next, a 7 g tungsten weight 140 was glued and fixed next to the magnetostrictive element 110. Furthermore, an NdFeB magnet 150 was attached to the electromagnetic steel sheet 121 side of the U-shaped lower fixing portion 170, and a magnetostrictive power generation device 100 was obtained in which the entire frame 130 was integrated with the magnetostrictive element 110.

The U-shaped lower fixing part 170 of the obtained magnetostrictive power generation device was fixed on the vibrator with adhesive. Next, a bias magnetic field was applied by an NdFeB magnet 150. The magnet strength (size) was changed and the magnet that gave the maximum peak voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be about 2800 A/m (350e) for oriented electromagnetic steel sheet and about 3200 A/m (400e) for non-oriented electromagnetic steel sheet. The vibrator was vibrated at 0.5 G, and the peak voltage at the resonant frequency was measured with an oscilloscope.

The resonant frequency of the device using oriented magnetic steel sheet as the magnetostrictive material was 215 Hz, and the resonant frequency of the device using non-oriented magnetic steel sheet was 227 Hz. The peak voltages are shown in Table 1.

As is clear from the results in Table 1, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.

Example 2
In Example 2, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 221 (magnetostrictive material), and CFRP, which is a non-magnetic material, was used as the elastic material 222 to fabricate a magnetostrictive power generation device 200 having the structure shown in FIG.

A magnetostrictive power generation device was assembled in the same manner as in Example 1, except that the thickness of the CFRP, which is an elastic material, for the magnetostrictive element portion corresponding to the magnetostrictive element 210 was thinned to 0.3 mm, and the thickness of the CFRP other than the magnetostrictive element portion was 0.5 mm, to obtain a magnetostrictive power generation device 200 in which the entire frame 230 (i.e., 100%) is integral with the magnetostrictive element 210. In this device, the thickness of the stress control portion 212 was thinned to make it easier for the magnetostrictive element portion to vibrate.

When the magnetostrictive power generation device 200 was evaluated in the same manner as in Example 1, the resonant frequency was 155 Hz. The peak voltage is shown in Table 2.

As is clear from the results in Table 2, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration. In addition, the thickness of the stress control section 212 was made thinner than in Example 1, resulting in a decrease in the resonant frequency, but the amplitude of the magnetostrictive element section was increased, improving the peak value of the generated voltage.

Example 3
In Example 3, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 321 (magnetostrictive material), and SUS304, a magnetic material, was used as the elastic material 322 to fabricate the magnetostrictive generating device 300 having the structure shown in FIG.

As the magnetic steel sheet 321, a grain-oriented magnetic steel sheet 27ZH100 with a coating manufactured by Nippon Steel Corporation was used. The thickness was 0.27 mm, and the crystal orientation was a {110}[100] GOSS texture. The grain-oriented magnetic steel sheet was cut by shearing to a length of 100 mm and a width of 6 mm with the longitudinal direction of the grain-oriented magnetic steel sheet set to the [100] direction. The sheet was then bent into a U-shape as shown in FIG. 3 to adjust the shape. The length corresponding to the lower fixing part 370 was about 40 mm, and the length of the part where the upper detection coil 360 and weight 340 were attached was about 40 mm.
After bending the grain-oriented electrical steel sheet into a U-shape, it was annealed in a vacuum at 800° C. for 2 hours to remove distortion.

A non-magnetic material, SUS304, having a thickness of 0.5 mm and a width of 6 mm, was used as the elastic material 322. The elastic material 322 was cut to a length slightly longer than 140 mm so that it could be integrated with the U-shaped electromagnetic steel plate, and was then molded into a U-shape to adjust the shape.
The SUS304 molded into a U-shape was subjected to solution treatment by holding in a vacuum at 1050° C. for 1 minute and then gas quenching to remove the effects of cutting distortion.

A U-shaped directional electromagnetic steel sheet 321 and a U-shaped SUS304 (elastic material 322) were bonded together at room temperature using an epoxy adhesive to form a laminate 320. A part of the frame (100 mm/140 mm = approximately 71%) was formed from the laminate, and an integrated structure was obtained in which the elastic material 322 extending from the stress control unit 312 of the magnetostrictive element 310 and the entire frame 330 were integrated. The magnetostrictive power generation device 300 was fabricated using the integrated structure obtained in the same manner as in Example 1.

When the magnetostrictive power generation device 300 was evaluated in the same manner as in Example 1, the resonant frequency was 98 Hz. The peak voltage is shown in Table 3.

As is clear from the results in Table 3, the device of the present invention showed a power generation performance of 500 mV or more in response to external vibration.

Example 4
In Example 4, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 421 (magnetostrictive material), and SS400, which is a magnetic material, was used as the elastic material 422 to fabricate a magnetostrictive generating device 400 having the structure shown in FIG.

The same grain-oriented electromagnetic steel sheet as in Example 3 was used as the electromagnetic steel sheet 421, and it was shaped into a U-shape.

The elastic material 422 was a magnetic material SS400 with a thickness of 0.5 mm and a width of 6 mm. The elastic material 422 was cut to a length slightly longer than 140 mm so that it could be integrated with the U-shaped electromagnetic steel plate, and then molded into a U-shape to adjust the shape.
The SS400 molded into a U-shape was held at 800° C. for 30 minutes in a vacuum and then cooled in the furnace to remove the effects of cutting distortion.

A U-shaped directional electromagnetic steel sheet and a U-shaped SS400 were bonded together at room temperature using an epoxy adhesive to form a laminate 420, and a part of the frame (100 mm/140 mm = approximately 71%) was formed from the laminate, and an integrated structure was obtained in which the elastic material 422 extending from the stress control section 412 of the magnetostrictive element 410 and the entire frame 430 were integrated. Using the integrated structure obtained, a magnetostrictive power generation device 400 was fabricated in the same manner as in Example 1. The magnet strength (size) was changed and the magnet that produced the maximum peak voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be approximately 4000 A/m (500 e).

When the magnetostrictive power generation device 400 was evaluated in the same manner as in Example 1, the resonant frequency was 104 Hz. The peak voltage is shown in Table 4.

As is clear from the results in Table 4, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration. However, in this device in which the elastic material forming the stress control section 412 is a magnetic material (SS400), the bias magnetic field also flows through the stress control section 412. Therefore, although a larger and stronger magnet was used than in Example 3, it was not as easy to adjust the bias magnetic field as in Example 3 in which the elastic material 322 forming the stress control section 312 was a non-magnetic material, and as a result, the peak voltage was slightly lower than in Example 3.

Example 5
In Example 5, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 521 (magnetostrictive material), and SUS304, a magnetic material, was used as the elastic material 522 to fabricate a magnetostrictive generating device 500 having the structure shown in FIG.

A magnetostrictive power generation device 500 was fabricated in the same manner as in Example 3, except that the length of the electromagnetic steel plate was 70 mm and magnets were placed on both sides of the power generation magnetostrictive element 510. A part of the frame of the fabricated device (70 mm/140 mm = 50%) was composed of a laminate, and the remaining part of the frame was integrally formed with the elastic material 522 extending from the stress control part 512 of the magnetostrictive element 510. Two magnets were used, and the two magnets were attached with opposite polarities so that the magnetic fields would not cancel each other out within the magnetostrictive element. The magnet strength (size) was changed and the magnet that maximized the peak voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be approximately 2800 A/m (350 e).

When the magnetostrictive power generation device 500 was evaluated in the same manner as in Example 1, the resonant frequency was 108 Hz. The peak voltage is shown in Table 5.

As is clear from the results in Table 5, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.

Example 6
In Example 1, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 621 (magnetostrictive material), and CFRP, which is a non-magnetic material, was used as the elastic material 622 to fabricate a magnetostrictive generating device 600 having the structure shown in FIG.

The same oriented magnetic steel sheet and CFRP as in Example 1 were cut to a length of 80 mm, and without bending them into a U-shape, they were stuck together at room temperature using an epoxy adhesive to form a laminate 620, and an integrated structure was obtained consisting of the magnetostrictive element portion corresponding to the magnetostrictive element 610 and the entire frame 630 (i.e., 100%). The magnetostrictive power generation device 600 was fabricated in the same manner as in Example 1 using the integrated structure obtained.

When the magnetostrictive power generation device 600 was evaluated in the same manner as in Example 1, the resonant frequency was 248 Hz. The peak voltage is shown in Table 6.

As is clear from the results in Table 6, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.

(Example 7)
In Example 7, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 721 (magnetostrictive material), and CFRP, which is a non-magnetic material, was used as the elastic material 722 to fabricate a magnetostrictive generating device 700 having the structure shown in FIG.

As the grain-oriented electrical steel sheet, grain-oriented electrical steel sheet 27ZH100 with coating made by Nippon Steel Corporation was used. The thickness was 0.27 mm, and the crystal orientation was {110}[100] GOSS texture. The longitudinal direction of the grain-oriented electrical steel sheet was set to the [100] direction, and the sheet was sheared to a length of 140 mm and a width of 6 mm. The sheet was then bent into a U-shape as shown in FIG. 7 to adjust the shape. The length corresponding to the lower fixing part 770 was about 80 mm, and the length of the part where the upper detection coil 760 and weight 740 were attached was about 40 mm.
After bending the grain-oriented electrical steel sheet into a U-shape, the sheet was annealed in a vacuum at 800° C. for 2 hours to remove distortion.

The elastic material 722 was made of non-magnetic CFRP with a thickness of 0.3 mm and a width of 6 mm. It was cut to a length of 40 mm with the carbon fiber direction as the longitudinal direction.

As shown in FIG. 7, the cut CFRP was attached to a grain-oriented electromagnetic steel plate bent into a U-shape using an epoxy-based adhesive at room temperature to form a laminate 720, and a portion of the frame 730 (40 mm/140 mm = approximately 29%) was formed from the above-mentioned laminate, resulting in an integrated structure in which the electromagnetic steel plate extending from the magnetostrictive portion 711 of the magnetostrictive element 710 and the entire frame 730 are integrated. Furthermore, SUS304 blocks were attached to the grain-oriented electromagnetic steel plate as supports 780 using an epoxy-based adhesive. Using the resulting structure, a magnetostrictive power generation device 700 was fabricated in the same manner as in Example 1.

When the magnetostrictive power generation device 700 was evaluated in the same manner as in Example 1, the resonant frequency was 165 Hz. The peak voltage is shown in Table 7.

As is clear from the results in Table 7, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration. Furthermore, because vibration is more likely to occur, the peak voltage was improved compared to the device of Example 1, which has a similar configuration.

(Example 8)
A magnetostrictive generating device 800 was fabricated in the same manner as in Example 7, except that the magnet was changed to two magnets 850. The magnet strength (size) was changed and the magnet that maximized the peak voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be about 2800 A/m (350 e).

When the magnetostrictive power generation device 800 was evaluated in the same manner as in Example 1, the resonant frequency was 157 Hz. The peak voltage is shown in Table 8.

As is clear from the results in Table 8, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.

(Comparative Example 1)
In Comparative Example 1, a grain-oriented electrical steel sheet was used as the magnetostrictive portion 911, and SS400, which is a magnetic material, was used as the elastic material 922 to fabricate a magnetostrictive generating device 900 having the structure shown in FIG.

As the grain-oriented electrical steel sheet, grain-oriented electrical steel sheet 27ZH100 with coating manufactured by Nippon Steel Corporation was used. It had a thickness of 0.27 mm and a crystal orientation of {110}[100] GOSS texture. The grain-oriented electrical steel sheet was sheared to a length of 20 mm and a width of 6 mm, and further annealed in a vacuum at 800°C for 2 hours to remove distortion, to form magnetostrictive portion 911.

The elastic material 922 used was SS400 with a width of 6 mm and a length of 140 mm. The thickness was 0.5 mm at the portion where the magnetostrictive portion 911 was attached (corresponding to the stress control portion 912), and 0.8 mm at other portions. The material was bent into a U-shape as shown in Fig. 9 to adjust the shape. The length corresponding to the lower fixing portion 970 was about 80 mm, and the length of the portion where the upper detection coil 960 and weight 940 were attached was about 40 mm.
The SS400 molded into a U-shape was held at 800° C. for 30 minutes in a vacuum and then cooled in the furnace to remove the effects of cutting distortion.

The magnetostrictive portion 911 was attached to the portion of the elastic material bent into a U-shape corresponding to the stress control portion 912 at room temperature using an epoxy adhesive to form a portion corresponding to the magnetostrictive element 910, and an integrated structure was obtained in which the elastic material 922 extending from the stress control portion 912 of the magnetostrictive element 910 and the entire frame 930 were integrated. In this integrated structure, the frame does not have a portion formed of a laminate including an electromagnetic steel plate extending from the magnetostrictive portion and an elastic material extending from the stress control portion. Using the obtained integrated structure, a magnetostrictive generating device 900 was produced in the same manner as in Example 1. The magnetostrictive generating device 900 further has a weight 940 for applying bending strain to the magnetostrictive portion and a magnet 950 for applying a bias magnetic field, and can be fixed on the vibrator by a fixing portion 970.

When the magnetostrictive power generation device 900 was evaluated in the same manner as in Example 1, the resonant frequency was 118 Hz. The peak voltage is shown in Table 9.

As is clear from the results in Table 9, the comparative example device showed a power generation performance of 500 mV or more in response to external vibration, but the bias magnetic field also flowed through the elastic material SS400. In addition, since the frame did not have a portion composed of a laminate including the electromagnetic steel plate extending from the magnetostrictive section and the elastic material extending from the stress control section, it was not easy to bring both ends of the magnetostrictive section into close contact with the stress control section. As a result, a magnetic gap was created, making it difficult to adjust the bias magnetic field using magnets, and the peak voltage was lower than that of the device of Example 4, which had a similar configuration.

(Example 10 and Comparative Example 2)
Each of the devices produced in Examples 1 to 8 and Comparative Example 1 was subjected to continuous vibration using a vibrator.

As a result, all of the devices of Examples 1 to 8, in which at least a portion of the frame was composed of a laminate including electromagnetic steel plates extending from the magnetostrictive portion and elastic material extending from the stress control portion, continued to function without problems even after 24 hours had passed. On the other hand, in the device of Comparative Example 1, in which the joint was present in the magnetostrictive element, peeling occurred between the magnetostrictive portion and the elastic material approximately 3 hours after vibration began. This is thought to be because continuous strain was applied to the magnetostrictive element by the vibration, causing stress concentration at the joint, resulting in peeling.

(Example 11)
In Example 11, a magnetostrictive power generation device 1000 having the structure shown in Figure 10 was manufactured using a directional electromagnetic steel sheet or a non-directional electromagnetic steel sheet as the electromagnetic steel sheet 1021 (magnetostrictive material) and CFRP, which is a non-magnetic material, as the elastic material 1022.

As the grain-oriented electrical steel sheet, grain-oriented electrical steel sheet 27ZH100 with coating made by Nippon Steel Corporation was used. The thickness was 0.27 mm, and the crystal orientation was {110}[100] GOSS texture. The longitudinal direction of the grain-oriented electrical steel sheet was set to the [100] direction, and the sheet was sheared to a length of 140 mm and a width of 6 mm. The sheet was bent into a U-shape as shown in FIG. 10 to adjust the shape. The length corresponding to the lower fixing part 1070 was about 80 mm, and the length of the part where the upper detection coil 1060 and weight 1040 were attached was about 40 mm.
After bending the grain-oriented electrical steel sheet into a U-shape, the sheet was annealed in a vacuum at 800° C. for 2 hours to remove distortion.

As the non-oriented electrical steel sheet, a non-oriented electrical steel sheet 35H210 with coating manufactured by Nippon Steel Corporation was used. The thickness was 0.35 mm. The non-oriented electrical steel sheet was sheared to a length of 140 mm and a width of 6 mm. The sheet was bent into a U-shape as shown in FIG. 10 to adjust the shape. The length corresponding to the lower fixing part 1070 was about 80 mm, and the length of the part where the upper detection coil 1060 and weight 1040 were attached was about 40 mm.
After bending the non-oriented electrical steel sheet into a U-shape, the sheet was annealed in a vacuum at 740° C. for 2 hours to remove distortion.

The elastic material 1022 was made of non-magnetic CFRP with a thickness of 0.5 mm and a width of 6 mm. The carbon fibers were cut to a length slightly shorter than 140 mm so that they could be integrated with the U-shaped electromagnetic steel plate, with the direction of the carbon fibers being the longitudinal direction, and the material was then formed into a U-shape by heat pressing.

A U-shaped directional or non-directional electromagnetic steel sheet 1021 and a U-shaped CFRP (elastic material 1022) were bonded together at room temperature using an epoxy adhesive to form a laminate 1020, and an integrated structure was obtained of the magnetostrictive element portion corresponding to the magnetostrictive element 1010 and the entire frame 1030 (i.e., 100%). A 5,000-turn detection coil 1060 was loaded into the part of the integrated structure corresponding to the magnetostrictive element. The length of the coil was 15 mm. Next, a 7 g tungsten weight 1040 was glued and fixed next to the magnetostrictive element 1010. Furthermore, an NdFeB magnet 1050 was attached to the elastic material 1022 side of the U-shaped lower fixing portion 1070, and a magnetostrictive power generation device 1000 was obtained in which the entire frame 1030 was integrated with the magnetostrictive element 1010.

The U-shaped lower fixing part 1070 of the obtained magnetostrictive power generation device was fixed on the vibrator with adhesive. Next, a bias magnetic field was applied by an NdFeB magnet 1050. The voltage was measured by changing the strength (size) of the magnet, and a magnet that generated a relatively large voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be about 2800 A/m (350e) for oriented electromagnetic steel sheet and 3200 A/m (400e) for non-oriented electromagnetic steel sheet. The vibrator was vibrated at 0.5 G, and the peak voltage at the resonant frequency was measured with an oscilloscope.

The resonant frequency of the device using oriented magnetic steel sheet as the magnetostrictive material was 226 Hz, and the resonant frequency of the device using non-oriented magnetic steel sheet was 239 Hz. The peak voltages are shown in Table 10.

As is clear from the results in Table 10, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.

Example 12
In Example 12, a magnetostrictive generating device 1100 having the structure shown in Figure 11 was manufactured, in which a grain-oriented electromagnetic steel plate was used as the electromagnetic steel plate 1121 (magnetostrictive material), CFRP, which is a non-magnetic material, was used as the elastic material 1122, and SUS304 blocks were provided as the supports 1180.

The device in FIG. 11 was fabricated in substantially the same manner as in Example 11, except that after forming the frame 1130, SUS304 blocks were used as supports 1180 and attached to the elastic material 1122 (CFRP) using an epoxy adhesive.

When the magnetostrictive power generating device 1100 was evaluated in the same manner as in Example 11, the resonant frequency was 384 Hz. The peak voltage is shown in Table 11.

As is clear from the results in Table 11, the device of the present invention showed a power generation performance of 500 mV or more in response to external vibration. In this example, SUS304 blocks were used as supports and attached to the CFRP with an epoxy adhesive, which shortened the length of the vibrating laminate and made it possible to increase the resonance frequency from 226 Hz in the device in Figure 10 to 384 Hz. Furthermore, because the resonance frequency increased and the amplitude decreased, the peak value of the generated voltage was 746 mV, which was smaller than the 829 mV of the directional electromagnetic steel sheet in Table 10, but still showed a power generation performance of 500 mV or more.

In addition, in device 1100, the laminate on the right side of the support vibrates, so the length of the laminate that vibrates can be adjusted by the position where the support is attached, and it is also possible to adjust the resonant frequency.

(Example 13)
In Example 13, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 1221 (magnetostrictive material), and SUS304, a non-magnetic material, was used as the elastic material 1222 to fabricate a magnetostrictive generating device 1200 having the structure shown in FIG.

As the grain-oriented electrical steel sheet, grain-oriented electrical steel sheet 27ZH100 with coating made by Nippon Steel Corporation was used. The thickness was 0.27 mm, and the crystal orientation was {110}[100] GOSS texture. The longitudinal direction of the grain-oriented electrical steel sheet was set to the [100] direction, and the sheet was sheared to a length of 130 mm and a width of 6 mm. The sheet was bent into a shape having a U-shaped portion and an L-shaped portion as shown in FIG. 12. The length corresponding to the lower fixing portion 1270 was about 40 mm, and the length of the portion where the upper detection coil 1260 and weight 1240 were attached was about 40 mm.
After bending into a shape having a U-shaped portion and an L-shaped portion, the bent portion was annealed in a vacuum at 800° C. for 2 hours to remove distortion.

A non-magnetic material, SUS304, having a thickness of 0.5 mm and a width of 6 mm, was used as the elastic material 1222. The elastic material was cut to a length slightly shorter than 130 mm so that it could be integrated with the electromagnetic steel plate having the U-shaped portion and the L-shaped portion, and the shape was adjusted by forming it into a shape having the U-shaped portion and the L-shaped portion.
A piece of SUS304 molded into a shape having a U-shaped portion and an L-shaped portion was held in a vacuum at 1050° C. for 1 minute, and then subjected to solution treatment by gas quenching to remove the effects of cutting distortion.

The molded directional electromagnetic steel sheet and SUS304 were bonded together at room temperature using an epoxy adhesive to form a laminate 1220, and an integrated structure was obtained consisting of the magnetostrictive element portion corresponding to the magnetostrictive element 1210 and the entire frame 1230 (i.e., 100%). A 5,000-turn detection coil was loaded into the part of the integrated structure corresponding to the magnetostrictive element. The coil length was 15 mm. Next, a 7 g tungsten weight 1240 was glued and fixed next to the magnetostrictive element 1210. Furthermore, an NdFeB magnet 1250 was attached to the inside (elastic material 1222 side) of the tip end of the L-shaped bent part of the obtained magnetostrictive generating device, and a magnetostrictive generating device 1200 was obtained in which the entire frame 1230 was integrated with the magnetostrictive element 1210.

The U-shaped lower fixing part 1270 of the obtained magnetostrictive power generation device was fixed on the top of a vibrator with adhesive. Next, a bias magnetic field was applied by an NdFeB magnet 1250. The voltage was measured by changing the strength (size) of the magnet, and a magnet that generated a relatively large voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be about 2800 A/m (350e) for directional electromagnetic steel sheet. The vibrator was vibrated at 0.5 G, and the peak voltage at the resonant frequency was measured with an oscilloscope.

The resonant frequency of the device using grain-oriented magnetic steel sheet as the magnetostrictive material was 104 Hz. The peak voltage is shown in Table 12.

As is clear from the results in Table 12, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.

(Example 14)
In Example 14, a magnetostrictive generating device 1300 having the structure shown in Figure 13 was produced, in which a grain-oriented electromagnetic steel plate was used as the electromagnetic steel plate 1321 (magnetostrictive material), SUS304, a non-magnetic material, was used as the elastic material 1322, and SUS304 blocks were provided as the supports 1380.

The device in FIG. 13 was fabricated in substantially the same manner as in Example 13, except that after forming the frame 1330, blocks of SUS304 were attached to the elastic material 1322 (SUS304) as supports 1380 using an epoxy adhesive.

When the magnetostrictive power generating device 1300 was evaluated in the same manner as in Example 13, the resonant frequency was 177 Hz. The peak voltage is shown in Table 13.

As is clear from the results in Table 13, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration. In this example, SUS304 blocks were used as supports and attached to an elastic material (SUS304) with an epoxy adhesive, which shortened the length of the vibrating laminate and made it possible to increase the resonance frequency from 104 Hz in the device in Figure 12 to 177 Hz. Because the resonance frequency increased and the amplitude decreased, the peak value of the generated voltage was 886 mV, which was smaller than the 987 mV in Table 12, but it still exhibited a power generation performance of 500 mV or more.

In addition, in device 1300, the laminate on the right side of the support vibrates, so the length of the laminate that vibrates can be adjusted by the position where the support is attached, and it is also possible to adjust the resonant frequency.

(Example 15)
In Example 15, a magnetostrictive generating device 1400 having the structure shown in FIG. 14 was fabricated using a grain-oriented electromagnetic steel sheet as the electromagnetic steel sheet 1421 (magnetostrictive material) and SUS304, a nonmagnetic material, as the elastic material 1422.

The device in FIG. 14 was fabricated in substantially the same manner as in Example 12, except that when forming the frame 1430, the length of the SUS304 to be bonded to the grain-oriented electromagnetic steel plate was shortened so that there would be no elastic material 1422 in the area where the NdFeB magnet 1450 was to be installed. Furthermore, the NdFeB magnet 1450 was directly attached to the grain-oriented electromagnetic steel plate 1421.

The U-shaped lower fixing part 1470 of the obtained magnetostrictive power generation device was fixed on the vibrator with adhesive. Next, a bias magnetic field was applied by an NdFeB magnet 1450. The voltage was measured by changing the strength (size) of the magnet, and a magnet that generated a relatively large voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be about 2800 A/m (350e) for directional electromagnetic steel sheet. The vibrator was vibrated at 0.5 G, and the peak voltage at the resonant frequency was measured with an oscilloscope.

The resonant frequency of the device using grain-oriented magnetic steel sheet as the magnetostrictive material was 101 Hz. The peak voltage is shown in Table 14.

As is clear from the results in Table 14, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.

In addition, compared to device 1200 of Example 13, device 1400 does not have an elastic material (SUS304, a non-magnetic material) between the magnet and the directional electromagnetic steel plate, so the effect of the magnetic gap is smaller. Therefore, it was possible to use magnets that are smaller in size than the NdFeB magnets used in device 1200.

(Example 16)
In Example 16, a magnetostrictive generating device 1500 having the structure shown in Figure 15 was produced, in which a grain-oriented electromagnetic steel plate was used as the electromagnetic steel plate 1521 (magnetostrictive material), SUS304, a non-magnetic material, was used as the elastic material 1522, and SUS304 blocks were provided as the supports 1580.

The device in FIG. 15 was fabricated in substantially the same manner as in Example 15, except that after forming the frame 1530, blocks of SUS304 were attached to the elastic material 1522 (SUS304) as supports 1580 using an epoxy adhesive.

When the magnetostrictive power generating device 1500 was evaluated in the same manner as in Example 15, the resonant frequency was 172 Hz. The peak voltage is shown in Table 15.

As is clear from the results in Table 15, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration. In this example, SUS304 blocks were used as supports and attached to an elastic material (SUS304) with an epoxy adhesive, which shortened the length of the vibrating laminate and made it possible to increase the resonance frequency from 101 Hz in device 1400 in Figure 14 to 172 Hz. Because the resonance frequency increased and the amplitude decreased, the peak value of the generated voltage was 890 mV, which was smaller than the 989 mV in Table 14, but it still exhibited a power generation performance of 500 mV or more.

In addition, in device 1500, the laminate on the right side of the support vibrates, so the length of the laminate that vibrates can be adjusted by the position where the support is attached, and it is also possible to adjust the resonant frequency.

(Example 17)
In Example 17, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 1621 (magnetostrictive material) and SUS304, a non-magnetic material, was used as the elastic material 1622 to fabricate a magnetostrictive generating device 1600 having the structure shown in FIG.

As the grain-oriented electrical steel sheet, grain-oriented electrical steel sheet 27ZH100 with coating made by Nippon Steel Corporation was used. The thickness was 0.27 mm, and the crystal orientation was {110}[100] GOSS texture. The grain-oriented electrical steel sheet was cut by shearing to a length of 110 mm and a width of 6 mm with the longitudinal direction of the grain-oriented electrical steel sheet set to the [100] direction. The shape was adjusted by bending the sheet into a shape having a U-shaped portion and two L-shaped portions as shown in FIG. 16. The length corresponding to the lower fixing portion 1670 was about 35 mm, and the length of the portion where the upper detection coil 1660 and weight 1640 were attached was about 40 mm.
After bending into a shape having a U-shaped portion and two L-shaped portions, the material was annealed in a vacuum at 800° C. for 2 hours to remove distortion.

A non-magnetic material, SUS304, with a thickness of 0.5 mm and a width of 6 mm, was used as the elastic material 1622. The elastic material was cut to a length slightly shorter than 110 mm so that it could be integrated with the electromagnetic steel plate having the U-shaped portion and two L-shaped portions, and then molded into a shape having a U-shaped portion and two L-shaped portions to adjust the shape.
A piece of SUS304 molded into a shape having a U-shaped portion and two L-shaped portions was held in a vacuum at 1050°C for one minute, and then subjected to solution treatment by gas quenching to remove the effects of distortion due to cutting.

The molded directional electromagnetic steel sheet and SUS304 were bonded together at room temperature using an epoxy adhesive to form a laminate 1620, and an integrated structure was obtained consisting of the magnetostrictive element portion corresponding to the magnetostrictive element 1610 and the entire frame 1630 (i.e., 100%). A 5,000-turn detection coil was loaded into the part of the integrated structure corresponding to the magnetostrictive element. The coil length was 15 mm. Next, a 7 g tungsten weight 1640 was glued and fixed next to the magnetostrictive element 1610. Furthermore, an NdFeB magnet 1650 was attached to the upper elastic material 1622 side of the L-shaped shape near the end, and a magnetostrictive power generation device 1600 was obtained in which the entire frame 1630 was integrated with the magnetostrictive element 1610.

The U-shaped lower fixing part 1670 of the obtained magnetostrictive power generation device was fixed on the vibrator with adhesive. Next, a bias magnetic field was applied by an NdFeB magnet 1250. The voltage was measured by changing the strength (size) of the magnet, and a magnet that generated a relatively large voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be about 2800 A/m (350e) for directional electromagnetic steel sheet. The vibrator was vibrated at 0.5 G, and the peak voltage at the resonant frequency was measured with an oscilloscope.

The resonant frequency of the device using grain-oriented magnetic steel sheet as the magnetostrictive material was 105 Hz. The peak voltage is shown in Table 16.

As is clear from the results in Table 16, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration.
Furthermore, in device 1600, the magnet and magnetostrictive element portion can be brought closer together than in device 1000 of Example 11, so that the magnetic gap is narrower and a magnet smaller in size can be used than the NdFeB magnet used in device 1000.

(Example 18)
In Example 18, a magnetostrictive generating device 1700 having the structure shown in Figure 17 was produced, in which a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 1721 (magnetostrictive material), SUS304, a non-magnetic material, was used as the elastic material 1722, and SUS304 blocks were provided as the supports 1780.

The device in FIG. 17 was fabricated in substantially the same manner as in Example 17, except that after forming the frame 1730, blocks of SUS304 were attached to the elastic material 1722 (SUS304) as supports 1780 using an epoxy adhesive.

When the magnetostrictive power generating device 1700 was evaluated in the same manner as in Example 17, the resonant frequency was 173 Hz. The peak voltage is shown in Table 17.

As is clear from the results in Table 17, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration. In this example, SUS304 blocks were used as supports and attached to SUS304 with an epoxy adhesive, which shortened the length of the vibrating laminate and made it possible to increase the resonance frequency from 105 Hz in device 1600 in Figure 16 to 173 Hz. Furthermore, because the resonance frequency increased and the amplitude decreased, the peak value of the generated voltage was 892 mV, which was smaller than the 985 mV in Table 16, but still demonstrated a power generation performance of 500 mV or more.

(Example 19)
In Example 19, a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 1821 (magnetostrictive material), and SUS304, a nonmagnetic material, was used as the elastic material 1822 to fabricate a magnetostrictive generating device 1800 having the structure shown in FIG.

The device in FIG. 18 was fabricated in substantially the same manner as in Example 16, except that when forming the frame 1830, the length of the SUS304 to be bonded to the grain-oriented electromagnetic steel plate was shortened so that there would be no elastic material 1822 in the area where the NdFeB magnet 1850 was to be installed. Furthermore, the NdFeB magnet 1850 was directly attached to the grain-oriented electromagnetic steel plate 1821.

The U-shaped lower fixing part 1870 of the obtained magnetostrictive power generation device was fixed on the top of a vibrator with adhesive. Next, a bias magnetic field was applied by an NdFeB magnet 1850. The voltage was measured by changing the strength (size) of the magnet, and a magnet that generated a relatively large voltage was used. The strength of the magnetic field applied to the magnetostrictive element was estimated to be about 2800 A/m (350 e) for directional electromagnetic steel sheet. The vibrator was vibrated at 0.5 G, and the peak voltage at the resonant frequency was measured with an oscilloscope.

The resonant frequency of the device using grain-oriented magnetic steel sheet as the magnetostrictive material was 103 Hz. The peak voltage is shown in Table 18.

As is clear from the results in Table 18, devices using the magnetostrictive element of the present invention demonstrated a power generation performance of 500 mV or more in response to external vibration.

In addition, compared to device 1600 of Example 17, device 1800 does not have an elastic material (SUS304, a non-magnetic material) between the magnet and the directional electromagnetic steel plate, so the effect of the magnetic gap is smaller. Therefore, it was possible to use magnets that are smaller in size than the NdFeB magnets used in device 1600.

(Example 20)
In Example 20, a magnetostrictive generating device 1900 having the structure shown in Figure 19 was produced, in which a grain-oriented electromagnetic steel sheet was used as the electromagnetic steel sheet 1921 (magnetostrictive material), SUS304, a non-magnetic material, was used as the elastic material 1922, and SUS304 blocks were provided as the supports 1980.

The device in FIG. 19 was fabricated in substantially the same manner as in Example 19, except that after forming the frame 1930, blocks of SUS304 were attached to the elastic material 1922 (SUS304) as supports 1980 using an epoxy adhesive.

When the magnetostrictive power generating device 1900 was evaluated in the same manner as in Example 19, the resonant frequency was 169 Hz. The peak voltage is shown in Table 19.

As is clear from the results in Table 19, the device of the present invention exhibited a power generation performance of 500 mV or more in response to external vibration. In this example, SUS304 blocks were used as supports and attached to SUS304 with an epoxy adhesive, which shortened the length of the vibrating laminate and made it possible to increase the resonance frequency from 103 Hz in device 1800 in Figure 18 to 169 Hz. Because the resonance frequency increased and the amplitude decreased, the peak value of the generated voltage was 897 mV, which was smaller than the 992 mV in Table 18, but still demonstrated a power generation performance of 500 mV or more.

(Example 21)
Each of the devices produced in Examples 11 to 20 was subjected to continuous vibration using a vibrator.

As a result, all of the devices in Examples 11 to 20, in which at least a portion of the frame was composed of a laminate including an electromagnetic steel plate extending from the magnetostrictive section and an elastic material extending from the stress control section, continued to function without problems even after 24 hours had passed.

The present invention provides a magnetostrictive power generation device with stable performance that is low-cost, highly durable, and capable of generating power equivalent to or exceeding that of conventional magnetostrictive power generation devices. The magnetostrictive power generation element of the present invention is less expensive than conventional magnetostrictive elements, yet capable of generating power equivalent to or exceeding that of conventional elements, making it useful not only for wireless sensor modules in IoT and the like, but also as a power source for various devices.

100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900 Magnetostrictive power generation device 110, 210, 310, 410, 510, 610, 710, 810, 910, 1010, 1110, 1210, 1310, 1410, 1510, 1610, 1710, 1810, 1910, Magnetostrictive element for power generation 111, 211, 311, 411, 511, 611, 711, 811, 911, 1011, 1111, 1211, 1311, 1411, 1511, 1611, 1711, 1811, 1911 Magnetostrictive part (magnetic steel plate)
112, 212, 312, 412, 512, 612, 712, 812, 912, 1012, 1112, 1212, 1312, 1412, 1512, 1612, 1712, 1812, 1912 Stress control section (elastic material)
120, 220, 320, 420, 520, 620, 720, 820, 1020, 1120, 1220, 1320, 1420, 1520, 1620, 1720, 1820, 1920 Laminate 121, 221, 321, 421, 521, 621, 721, 821, 1021, 1121, 1221, 1321, 1421, 1521, 1621, 1721, 1821, 1921 Electromagnetic steel sheet 122, 222, 322, 422, 522, 622, 722, 822, 922, 1022, 1122, 1222, 1322, 1422, 1522, 1622, 1722, 1822, 1922 Elastic material 130, 230, 330, 430, 530, 630, 730, 830, 930, 1030, 1130, 1230, 1330, 1430, 1530, 1630, 1730, 1830, 1930 Frame 140, 240, 340, 440, 550, 640, 740, 840, 940, 1040, 1140, 1240, 1340, 1440, 1540, 1640, 1740, 1840, 1940 950, 1050, 1150, 1250, 1350, 1450, 1550, 1650, 1750, 1850, 1950
Magnet 160, 260, 360, 460, 560, 660, 760, 860, 960, 1060, 1160, 1260, 1360, 1460, 1560, 1660, 1760, 1860, 1960 Detection coil 170, 270, 370, 470, 570, 670, 770, 870, 970, 1070, 1170, 1270, 1370, 1470, 1570, 1670, 1770, 1870, 1970 Fixing part 780, 880, 1180, 1380, 1580, 1780, 1980 Support

Claims (9)

a magnetostrictive element for power generation having a magnetostrictive portion formed of an electromagnetic steel plate and a stress control portion formed of an elastic material;
A magnetostrictive power generation device including the magnetostrictive element for power generation and a continuous frame,
At least a portion of the frame is composed of a laminate including the electromagnetic steel plate extending from the magnetostrictive portion and the elastic material extending from the stress control portion.
Magnetostrictive power generation device. The device according to claim 1, wherein the magnetic steel sheet is a grain-oriented magnetic steel sheet. The device according to claim 1, wherein the electrical steel sheet is a non-oriented electrical steel sheet. The device according to any one of claims 1 to 3, wherein the elastic material is a non-magnetic material. The device according to any one of claims 1 to 4, wherein the entire frame is integral with the electromagnetic steel plate extending from the magnetostrictive portion. The device according to any one of claims 1 to 4, wherein the entire frame is integral with the elastic material extending from the stress control portion. The device according to any one of claims 1 to 4, wherein the entire frame is integral with the magnetostrictive element for power generation. The device according to any one of claims 1 to 7, wherein the frame has a shape with at least one curved portion, and in the frame and the magnetostrictive element for power generation, the electromagnetic steel sheet is located inside the device, and the elastic material is located outside the device. The device according to any one of claims 1 to 7, wherein the frame has a shape with at least one curved portion, and in the frame and the magnetostrictive element for power generation, the elastic material is located inside the device, and the electromagnetic steel sheet is located outside the device.

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