Power generation element, power generation system, and encoder

Abstract

Provided is a power generation element or the like capable of reducing variations in the amount of power generation. A power generation element (100) is provided with: a magnetic member composite body (110) having a plurality of magnetic members (120) bundled into a bundle, each of the plurality of magnetic members (120) generating a large Barkhausen effect according to a change in an external magnetic field; and a coil (130) wound around the magnetic member complex (110). Each of the plurality of magnetic members (120) has a first magnetosensitive part (121) and a second magnetosensitive part (122), and the second magnetosensitive part (122) is more magnetic than the first magnetosensitive part (121). The first magnetosensitive part (121) is magnetized in the winding axis direction of the coil (130), and the magnetization direction does not change in accordance with a change in the direction of the external magnetic field. The plurality of magnetic members (120) include a first magnetic member (120a) in which the first magnetosensitive portion (121) is magnetized in a first direction, and a second magnetic member (120b) in which the first magnetosensitive portion (121) is magnetized in a second direction opposite to the first direction.

Description

Technical Field

[0001] The present disclosure relates to a power generation element, a power generation system, and an encoder, and particularly to a power generation element utilizing the large Barkhausen effect, a power generation system including the power generation element, and an encoder. Background Art

[0002] Conventionally, as an encoder for detecting the rotation of a motor or the like, an encoder that uses a power generation element utilizing the large Barkhausen effect to detect rotation without using a battery is known (for example, Patent Document 1). Such a power generation element has, for example, a structure in which a coil is wound around a magnetic member that generates the large Barkhausen effect. The magnetic flux density of the magnetic member that generates the large Barkhausen effect changes sharply according to changes in the external magnetic field. Therefore, due to the sharp change in the magnetic flux density, electricity is generated in the coil wound around the magnetic member. The encoder uses an electrical signal based on such electricity to detect the rotation of the motor or the like.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012 - 198067 Summary of the Invention

[0006] In the above-described encoder, when the deviation of the electricity generated by the power generation element is large, it may not be possible to accurately detect the rotation of the motor or the like.

[0007] The present disclosure has been made to solve such problems, and an object thereof is to provide a power generation element, a power generation system including the power generation element, and an encoder that can reduce the deviation of the generated power.

[0008] A power generation element according to one aspect of the present disclosure includes: a magnetic member complex having a plurality of magnetic members, wherein the plurality of magnetic members are bundled into a bundle, and each of the plurality of magnetic members generates a large Barkhausen effect according to changes in an external magnetic field; and a coil wound around the magnetic member complex. Each of the plurality of magnetic members has a first magnetosensitive portion and a second magnetosensitive portion, and the second magnetosensitive portion is softer magnetic than the first magnetosensitive portion. The first magnetosensitive portion is magnetized along the winding axis direction of the coil, and the magnetization direction does not change according to changes in the direction of the external magnetic field. The plurality of magnetic members include a first magnetic member in which the first magnetosensitive portion is magnetized in a first direction and a second magnetic member in which the first magnetosensitive portion is magnetized in a second direction opposite to the first direction.

[0009] In addition, a power generation system according to another aspect of the present disclosure includes: the power generation element of the above aspect; and a magnetic field application unit that applies a magnetic field to the power generation element and repeatedly reverses the orientation of the magnetic field applied to the power generation element, wherein the power generation element generates electricity due to the reversal of the orientation of the magnetic field applied by the magnetic field application unit.

[0010] In addition, an encoder according to another aspect of the present disclosure includes the power generation system of the above aspect, wherein the power generation element outputs the power generated due to the reversal of the orientation of the magnetic field applied by the magnetic field application unit.

[0011] According to the present disclosure, it is possible to provide a power generation element, a power generation system including the power generation element, and an encoder that can reduce the deviation in power generation amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. is an example of a schematic BH curve of a magnetic member that generates the Barkhausen effect.

[0013] Figure 2 FIG. is a cross-sectional view showing a schematic configuration of an encoder according to an embodiment.

[0014] Figure 3 FIG. is a top view of a magnet in an encoder according to an embodiment.

[0015] Figure 4 FIG. is a cross-sectional view showing a schematic configuration of a power generation element according to an embodiment.

[0016] Figure 5 FIG. is an example of a schematic BH curve of a first magnetic member according to an embodiment.

[0017] Figure 6 FIG. is an example of a schematic BH curve of a second magnetic member according to an embodiment.

[0018] Figure 7 FIG. is a graph obtained by Figure 5 superposing the BH curve of the first magnetic member shown in Figure 6 with the BH curve of the second magnetic member shown in

[0019] Figure 8 FIG. is a schematic diagram of a circuit used in the measurement of the power generation amount of a power generation element.

[0020] Figure 9 FIG. is a graph showing the measurement results of the magnitude of power generation of a power generation element in Measurement Example 1.

[0021] Figure 10 FIG. is a graph showing the measurement results of the magnitude of power generation of a power generation element in Measurement Example 2.

[0022] Figure 11 It is a diagram for explaining the arrangement of a plurality of magnetic members in the magnetic member composite related to the embodiment. Detailed Embodiment

[0023] (Process of obtaining one aspect of the present disclosure)

[0024] For example, a composite magnetic wire such as a Wiegand wire, whose magnetic properties are different between the central part and the peripheral part in the radial direction, is used as the magnetic member that generates the large Barkhausen effect. Regarding the Wiegand wire, one of the central part and the peripheral part is soft magnetic and the other is hard magnetic.

[0025] Here, the large Barkhausen effect will be described. Figure 1 It is a diagram showing an example of a schematic BH curve of a magnetic member that generates the large Barkhausen effect. In Figure 1 an example in which a composite magnetic wire with a soft magnetic peripheral part compared to the central part is used as the magnetic member is shown. In addition, Figure 1 it is a diagram when the direction of the magnetic field applied in the long side direction of the wire changes. In addition, in Figure 1 (1) to (6), a magnetic member with the direction of magnetization indicated by an arrow is schematically shown. The dotted arrow indicates the direction of magnetization of the soft magnetic peripheral part, and the solid arrow indicates the direction of magnetization of the hard magnetic central part. In addition, in Figure 1 the arrow indicating the direction of magnetization only indicates the direction of magnetization, and the direction of magnetization is indicated by an arrow of the same size regardless of the magnitude of magnetization.

[0026] When a magnetic field with a magnitude equal to or greater than a certain value is applied to the magnetic member along the long side direction of the magnetic member, as shown in Figure 1 (1), the central part and the peripheral part of the magnetic member are magnetized in the same direction. Even if the direction of the magnetic field changes as in Figure 1 (i), the magnetization direction of the soft magnetic peripheral part does not change due to the influence of the hard magnetic central part until a certain degree of magnetic field change. As shown in Figure 1 (2) and (3), at the part surrounded by the dotted line Ja where the magnetic field change exceeds the threshold, the magnetization direction of the soft magnetic peripheral part suddenly reverses. This phenomenon is also called the large Barkhausen jump. As a result, the magnetic flux density of the magnetic member changes sharply, and electricity (a generation pulse) is generated in the coil wound around the magnetic member. When the magnetic field is further changed, as shown in Figure 1 (4), the magnetization direction of the central part also reverses, and the magnetic member is along the same direction as Figure 1is magnetized in the (1) opposite direction. In this case, the direction of the magnetic field is also changed as in Figure 1 (ii) so that, as shown in Figure 1 (5) and (6), at the portion surrounded by the dashed line Jb where the change in the magnetic field exceeds the threshold value, the magnetization direction of the outer peripheral portion is suddenly reversed all at once. As a result, the magnetic flux density of the magnetic member changes sharply, and electricity (a power generation pulse) is generated again in the coil wound around the magnetic member. By detecting such a power generation pulse, the power generation element can be used for an encoder. In Figure 1 the case of the example shown, in one reciprocating change in the direction of the magnetic field, the magnetization direction of the magnetic member is reversed twice, so two power generation pulses are generated.

[0027] In a power generation element using such a magnetic member, when detecting power generation pulses repeatedly, there may be a deviation in the generated power in the power generation pulses. For example, when 5000 power generation pulses are detected, there may sometimes be detected a power generation pulse having a difference of more than 10 times the standard deviation (so-called 10σ) with respect to the average value of the generated power.

[0028] Therefore, in view of the above problems, in the present disclosure, an object is to provide a power generation element, a power generation system including the power generation element, and an encoder that can reduce the deviation in the amount of generated power.

[0029] Hereinafter, embodiments of the present disclosure will be described while referring to the attached Figure 1 drawings. In addition, the embodiments described below are all specific examples of the present disclosure. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions of the constituent elements, connection methods, etc. shown in the following embodiments are examples, and are not intended to limit the present disclosure. Therefore, regarding the constituent elements in the following embodiments that are not described in the independent claims of the present disclosure, they are described as optional constituent elements.

[0030] In addition, the drawings are schematic views and are not necessarily drawn precisely. Therefore, the scales, etc. are not necessarily the same in each drawing. In addition, in each drawing, the same reference numerals are given to structures that are substantially the same as those in other drawings, and repeated explanations are omitted or simplified.

[0031] In addition, in this specification, terms indicating the relationship between elements such as parallel, and terms indicating the shape of elements such as rectangles, and numerical ranges do not represent only a strict meaning, but mean that they also include substantially equivalent ranges, for example, a performance with a difference of about several %.

[0032] (Embodiment)

[0033] Hereinafter, an encoder 1, a power generation system 5, and a power generation element 100 according to the embodiment will be described.

[0034] [Structure]

[0035] First, the structures of the encoder 1, the power generation system 5, and the power generation element 100 according to this embodiment will be described.

[0036] Figure 2 is a cross-sectional view showing the schematic structure of the encoder 1 according to this embodiment. Figure 3 is a top view of the magnet 10 in the encoder 1 according to this embodiment. In addition, in Figure 2 the magnetic member complex 110 and the coil 130 housed in the housing 190 of the power generation element 100 are schematically represented by dashed lines. In addition, for easy observation, in Figure 3 the illustration of components other than the magnet 10, the rotating shaft 30, the magnetic member complex 110, and the coil 130 in the power generation element 100 is omitted.

[0037] Figure 2 The encoder 1 shown, for example, is a rotary encoder used in combination with a motor such as a servo motor. In addition, the encoder 1 is, for example, an absolute encoder of a power generation type. The encoder 1 detects, based on the electrical signal generated by the power generation element 100, the rotation angle, the rotation amount, the rotation speed, etc. of the rotating shaft 30 of, for example, a motor. The encoder 1 includes a power generation system 5, a control circuit 50, and a memory 60. The power generation system 5 includes a magnet 10, a rotating plate 20, a substrate 40, and a power generation element 100. In the encoder 1, the power generation element 100 in the power generation system 5 generates power according to the change in the magnetic field formed by the magnet 10 caused by the rotation of the magnet 10, and outputs the generated power as an electrical signal.

[0038] The rotating plate 20 is a plate-shaped member that rotates together with the rotating shaft 30 that is a driving part of a motor or the like. The central part of one main surface of the rotating plate 20 is attached to the end of the rotating shaft 30 in the axial direction of the rotating shaft 30 (the direction in which the rotating shaft 30 extends). The rotating plate 20 extends in a direction orthogonal to the axial direction of the rotating shaft 30. The rotating plate 20 rotates about a rotation axis A that passes through the center of the rotating shaft 30 and extends along the axial direction of the rotating shaft 30. The rotation operation of the rotating shaft 30 is synchronized with the rotation operation of the rotating device. The top view shape of the rotating plate 20 is, for example, circular. The rotating plate 20 is, for example, made of metal, resin, glass, or ceramic.

[0039] The rotating shaft 30 has a rod shape such as a cylindrical shape. The axis of the rotating shaft 30 coincides with the rotation axis A.

[0040] The magnet 10 is an example of a magnetic field applying unit that applies an external magnetic field to the power generation element 100. The magnet 10 can also be said to be a magnetic field generation source that forms an external magnetic field for the power generation element 100. The magnet 10 repeatedly reverses the orientation of the magnetic field applied to the power generation element 100. The magnet 10 is, for example, a plate-shaped magnet. The magnet 10 faces the rotating plate 20 and is located on the main surface of the rotating plate 20 opposite to the rotating shaft 30. In the present embodiment, a pair of magnets 10 are provided on the same main surface of the rotating plate 20. The thickness direction of the rotating plate 20 is the same as the thickness direction of the magnet 10 and is the axial direction of the rotating shaft 30. The pair of magnets 10 rotate about the rotating shaft 30 (that is, rotate about the rotation axis line A) together with the rotating plate 20. The pair of magnets 10 rotate due to the rotation of the rotating shaft 30, whereby the relative positional relationship between the pair of magnets 10 and the power generation element 100 changes, and the magnetic field from the pair of magnets 10 applied to the power generation element 100 also changes. The rotation directions of the pair of magnets 10 are, for example, both the clockwise direction and the counterclockwise direction, but may also be either the clockwise direction or the counterclockwise direction only.

[0041] The pair of magnets 10 sandwich the rotation axis line A of the rotating shaft 30 and are arranged at intervals on the same main surface of the rotating plate 20. That is, the rotation axis line A of the rotating shaft 30 is located between the pair of magnets 10, and a space is formed between the pair of magnets 10. In addition, the pair of magnets 10 are symmetrically arranged with the rotation axis line A sandwiched therebetween. The pair of magnets 10 have the same shape as each other.

[0042] The pair of magnets 10 are arranged along the rotation direction of the rotating shaft 30. The top view shape of each of the pair of magnets 10 is an arc shape along the rotation direction of the rotating shaft 30. In addition, only one of the pair of magnets 10 may be provided on the main surface of the rotating plate 20. Further, as long as the magnet 10 can change the magnetic field applied to the power generation element 100, it may be a magnet of other shapes such as a ring shape, a disk shape, or a rod shape. In addition, the magnet 10 is, for example, a permanent magnet, but may also be an electromagnet.

[0043] The N poles and S poles of each of the pair of magnets 10 are arranged along the direction in which the pair of magnets 10 are arranged. The arrangement order of the S poles and N poles of each of the pair of magnets 10 is the same. That is, the pair of magnets 10 are magnetized respectively along the direction in which the pair of magnets 10 are arranged. Therefore, the pair of magnets 10 respectively generate magnetic fields along the direction in which the pair of magnets 10 are arranged.

[0044] In one of the pair of magnets 10, the S pole is arranged facing the rotation axis A, and in the other magnet 10, the N pole is arranged facing the rotation axis A. Therefore, when the pair of magnets 10 rotate due to the rotation of the rotation shaft 30 so that the positions of the pair of magnets 10 are swapped with each other, the orientation of the magnetic field formed by the pair of magnets 10 is reversed. By rotating such a pair of magnets 10, the magnetic field applied to the power generation element 100 changes. Specifically, by rotating the pair of magnets 10, the orientation of the magnetic field applied to the power generation element 100 is repeatedly reversed.

[0045] The substrate 40 is located at a position facing the surface of the rotary plate 20 where the magnet 10 is arranged, with a gap between the substrate 40 and the rotary plate 20 and the magnet 10. That is, the rotation shaft 30, the rotary plate 20, the magnet 10, and the substrate 40 are arranged in sequence along the axial direction of the rotation shaft 30. The substrate 40 does not rotate together with the magnet 10 and the rotary plate 20. The substrate 40 is in the shape of a plate with the axial direction of the rotation shaft 30 as the thickness direction. The top view shape of the substrate 40 is, for example, circular. For example, when viewed from the axial direction of the rotation shaft 30, the centers of the rotation shaft 30, the rotary plate 20, and the substrate 40 coincide and are at the position of the rotation axis A.

[0046] The substrate 40 is, for example, a wiring substrate, on which electronic components such as the power generation element 100, the control circuit 50, and the memory 60 are mounted. Figure 2 In the example shown, the control circuit 50 and the memory 60 are mounted on the main surface of the substrate 40 facing the magnet 10, and the power generation element 100 is mounted on the main surface of the substrate 40 on the side opposite to the main surface facing the magnet 10. The substrate 40 is, for example, fixed to the housing constituting a part of the encoder 1 or the motor.

[0047] The power generation element 100 is located on the main surface of the substrate 40 on the side opposite to the main surface facing the magnet 10. Therefore, when viewed from the power generation element 100, the substrate 40 and the magnet 10 are arranged in the same direction. The power generation element 100 is arranged along the axial direction of the rotation shaft 30 with the magnet 10 and the rotary plate 20. Hereinafter, the direction indicated by the arrow Z in which the magnet 10, the rotary plate 20, and the power generation element 100 are arranged may sometimes be referred to as the "arrangement direction". In the present embodiment, the arrangement direction is parallel to the axial direction of the rotation shaft 30 and parallel to the direction perpendicular to the main surface 11 of the magnet 10. The power generation element 100 does not rotate together with the magnet 10 and the rotary plate 20.

[0048] When viewed from the rotating plate 20, the power generation element 100 is disposed on the opposite side of the substrate 40 in the axial direction of the rotating shaft 30. When viewed in the axial direction of the rotating shaft 30, the power generation element 100 does not overlap with the rotation axis A, but is disposed at a position deviated from the rotation axis A. When viewed in the axial direction of the rotating shaft 30, the power generation element 100 overlaps with the position where the magnet 10 passes during rotation. Further, the power generation element 100 extends along the main surface of the substrate 40 so as to extend in the tangential direction of the rotation direction of the magnet 10.

[0049] The power generation element 100 generates electricity according to the change in the magnetic field formed by the magnet 10 caused by the rotation of the magnet 10, specifically, the reversal of the orientation of the magnetic field, and outputs the generated electric power. The winding axis direction of the coil 130 of the power generation element 100 is the direction in which the power generation element 100 extends. The winding axis direction of the coil 130 is the direction indicated by the arrow X in the figure. Hereinafter, the winding axis direction of the coil 130 indicated by the arrow X in the figure may be simply referred to as the "winding axis direction".

[0050] The power generation element 100 includes, for example, a magnetic member composite 110, a coil 130, terminals 181, 182, and a housing 190.

[0051] The magnetic member composite 110 is a composite structure obtained by bundling a plurality of magnetic members that respectively generate the large Barkhausen effect into a bundle, and a power generation pulse is generated in the coil 130 wound around the magnetic member composite 110. Details of the magnetic member composite 110 and the coil 130 will be described later. In addition, the arrangement of the power generation element 100 is not particularly limited, and the power generation element 100 only needs to be located in the region where the magnetic field generated by the magnet 10 is applied and arranged so as to generate a power generation pulse due to the reversal of the orientation of the magnetic field caused by the rotation of the rotating shaft 30.

[0052] The terminals 181, 182 are members for electrically connecting the power generation element 100 to the substrate 40. The terminals 181, 182 are located at the end of the power generation element 100 facing the substrate 40. When viewed from the power generation element 100, the magnet 10 is arranged in the direction of the terminals 181, 182. The terminal 181 is electrically connected to one end of the wire constituting the coil 130, and the terminal 182 is electrically connected to the other end of the wire. That is, the coil 130 is electrically connected to the substrate 40 via the terminals 181, 182.

[0053] The housing 190 houses and supports the magnetic member complex 110 and the coil 130. The magnetic member complex 110 and the coil 130 are embedded, for example, in resin or the like within the housing 190. In addition, the housing 190 houses a part of the terminals 181 and 182. Further, the power generation element 100 does not have ferrite beads at the ends of the magnetic member complex 110 in the winding axis direction, and the housing 190 does not house ferrite beads. General power generation elements, for example, have ferrite beads disposed at the ends of magnetic members such as a Weigand wire, but even without ferrite beads, the power generation element 100 can generate power stably as described later, enabling miniaturization and cost reduction of the power generation element 100. The housing 190 faces the magnet 10 in the power generation element 100, for example. The housing 190 is fixed to the substrate 40 by a fixing member or the like, for example.

[0054] The control circuit 50 is located on the main surface of the substrate 40 facing the magnet 10. The control circuit 50 is electrically connected to the power generation element 100. The control circuit 50 acquires electrical signals such as power generation pulses generated by the power generation element 100, and detects (calculates) the rotation angle, rotation amount, rotational speed, etc. of the rotation shaft 30 of a motor or the like based on the acquired electrical signals. The control circuit 50 is, for example, an IC (integrated circuit) package or the like.

[0055] The memory 60 is located on the main surface of the substrate 40 facing the magnet 10. The memory 60 is connected to the control circuit 50. The memory 60 is a non-volatile memory such as a semiconductor memory for storing the results detected by the control circuit 50.

[0056] Next, the details of the power generation element 100 according to the present embodiment will be described.

[0057] Figure 4 FIG. is a cross-sectional view showing the schematic structure of the power generation element 100 according to the present embodiment. Figure 4 The figure shows a cross-section taken in a plane perpendicular to the rotation axis A and passing through the winding axis R1 of the coil 130. In addition, for easy observation, in Figure 4 the illustration of the terminals 181, the terminal 182, and the housing 190 is omitted.

[0058] As Figure 4 shown, the power generation element 100 includes a magnetic member complex 110 and a coil 130.

[0059] The magnetic member complex 110 has a plurality of magnetic members 120. In the magnetic member complex 110, the plurality of magnetic members 120 are bundled into a bundle. The positions of both ends of each of the plurality of magnetic members 120 in the winding axis direction are aligned with each other.

[0060] A plurality of magnetic members 120 are bundled together in such a way that their relative positions do not change. The method of bundling the plurality of magnetic members 120 together is not particularly limited. For example, the plurality of magnetic members 120 are fixed to each other by adhesion, joining, welding, etc. and thus bundled together. In addition, the plurality of magnetic members 120 can also be bundled together by being respectively supported by the housing 190, and can also be bundled together by the coil 130 or a belt (not shown), etc.

[0061] The magnetic member 120 is a magnetic member that generates a large Barkhausen effect in accordance with changes in an external magnetic field formed by the magnet 10 or the like. The magnetic member 120 has a first magnetosensitive portion 121 and a second magnetosensitive portion 122 having a magnetic property different from that of the first magnetosensitive portion 121. The second magnetosensitive portion 122 has a lower coercive force than the first magnetosensitive portion 121 and is soft magnetic. The magnetic member 120 is, for example, a long member having the winding axis direction of the coil 130 as the long side direction. The cross-sectional shape obtained by cutting the magnetic member 120 in the radial direction is, for example, circular or elliptical, but may also be other shapes such as rectangular or polygonal. In the winding axis direction, the length of the magnetic member 120 is, for example, longer than the length of the coil 130.

[0062] The magnetic member 120 is, for example, a composite magnetic wire such as a Weigand wire, which has different magnetic properties at the central portion and the outer peripheral portion in the radial direction. In the present embodiment, in the magnetic member 120, for example, the central portion in the radial direction is the first magnetosensitive portion 121 having a relatively high coercive force, and the outer peripheral portion in the radial direction is the second magnetosensitive portion 122 having a relatively low coercive force. The first magnetosensitive portion 121 and the second magnetosensitive portion 122 each extend in the winding axis direction. Both the first magnetosensitive portion 121 and the second magnetosensitive portion 122 are elongated in the winding axis direction. Specifically, the first magnetosensitive portion 121 is linear and extends in the winding axis direction, and the second magnetosensitive portion 122 is tubular and extends in the winding axis direction. The second magnetosensitive portion 122 covers the surface that becomes the outer periphery of the first magnetosensitive portion 121 when viewed from the winding axis direction, in other words, covers the surface extending along the winding axis direction. The first magnetosensitive portion 121 and the second magnetosensitive portion 122 are arranged in the direction intersecting (e.g., orthogonal) to the winding axis direction, that is, in the radial direction of the magnetic member 120. In addition, the magnetic member 120 is not limited to such a shape, and any magnetic member that can generate the large Barkhausen effect by the first magnetosensitive portion 121 and the second magnetosensitive portion 122 having different magnetic properties is acceptable. For example, in the magnetic member 120, the central portion may be the second magnetosensitive portion 122 and the outer peripheral portion may be the first magnetosensitive portion 121. In addition, the magnetic member 120 may be, for example, a magnetic member having a structure formed by laminating thin films with different magnetic properties. Also, the coercive force may not change abruptly between the first magnetosensitive portion 121 and the second magnetosensitive portion 122, or the coercive force may gradually change near the boundary between the first magnetosensitive portion 121 and the second magnetosensitive portion 122. In addition, for example, an intermediate layer may exist between the first magnetosensitive portion 121 and the second magnetosensitive portion 122, and the intermediate layer has a coercive force between the coercive force of the first magnetosensitive portion 121 and the coercive force of the second magnetosensitive portion 122.

[0063] The first magnetosensitive portion 121 is magnetized along the winding axis direction. For example, the first magnetosensitive portion 121 is magnetized by being applied with a magnetic field of 500 Oe or more. The first magnetosensitive portion 121 may also be magnetized by being applied with a magnetic field of 1000 Oe or more, or may also be magnetized by being applied with a magnetic field of 3000 Oe or more. The magnetization direction of the first magnetosensitive portion 121 does not change according to the change in the direction of the external magnetic field formed by the magnet 10 or the like. For example, when an external magnetic field of 60 Oe or less is applied to the power generation element 100, the magnetization direction and the magnetization state of the first magnetosensitive portion 121 do not substantially change according to the change in the direction of the external magnetic field. In addition, the first magnetosensitive portion 121 may be saturated magnetized. In addition, here, Oe is the unit of the intensity of the magnetic field of oersted, and 1 Oe = (1 / 4π)·10 3 A / m. In addition, π is the ratio of the circumference of a circle to its diameter.

[0064] The plurality of magnetic members 120 includes a first magnetic member 120a and a second magnetic member 120b. The magnetization direction of the first magnetic member 120a is opposite to the magnetization direction of the second magnetic member 120b. As Figure 4 shown, the first magnetic member 120a is magnetized in a first direction indicated by an arrow B1. On the other hand, the second magnetic member 120b is magnetized in a second direction opposite to the first direction indicated by an arrow B2.

[0065] The number of the first magnetic members 120a included in the plurality of magnetic members 120 is the same as the number of the second magnetic members 120b. In the example Figure 4 shown, the number of each of the first magnetic member 120a and the second magnetic member 120b is one, but the plurality of magnetic members 120 may also include a plurality of each of the first magnetic member 120a and the second magnetic member 120b. Thus, the change in magnetic flux of the magnetic member complex 110 becomes large, and therefore the power generation amount of the power generation element 100 can be increased.

[0066] In the example Figure 4 shown, the first magnetic member 120a and the second magnetic member 120b are arranged and bundled in a direction orthogonal to the winding axis direction on a plane perpendicular to the arrangement direction.

[0067] The coil 130 is a coil obtained by winding a wire forming the coil 130 around the magnetic member complex 110. Specifically, the coil 130 is wound around a winding axis R1 that passes through the center of the magnetic member complex 110 and extends in the long side direction of the magnetic member complex 110 (the plurality of magnetic members 120).

[0068] [Magnetic characteristics of magnetic member complex]

[0069] Next, the large Barkhausen effect in the magnetic member complex 110 will be described. Figure 5 is a diagram showing an example of a schematic BH curve of the first magnetic member 120a. Figure 6 is a diagram showing an example of a schematic BH curve of the second magnetic member 120b. In Figure 5 and Figure 6 , similar to Figure 1 , the magnetization directions in the first magnetic member 120a and the second magnetic member 120b are respectively indicated by solid and dashed arrows. In addition, in Figure 5 and Figure 6 , the arrows indicating the magnetization directions only indicate the magnetization directions, and the magnetization directions are indicated by arrows of the same size regardless of the magnitude of the magnetization. Further, Figure 7 is to Figure 5The figure obtained by overlapping the BH curve of the first magnetic member 120a shown with Figure 6 the BH curve of the second magnetic member 120b shown.

[0070] As Figure 5 shown in (1) of, in the first magnetic member 120a, even when a magnetic field in a direction opposite to the magnetization direction of the first magnetosensitive portion 121 is applied, the magnetization direction of the first magnetosensitive portion 121 does not change. Therefore, the first magnetosensitive portion 121 and the second magnetosensitive portion 122 are magnetized in opposite directions. Thus, when the direction of the magnetic field changes as Figure 5 shown in (i) of, as Figure 5 shown in (2) of, the magnetization direction of the second magnetosensitive portion 122 is reversed to be the same as the magnetization direction of the first magnetosensitive portion 121. In this case, it is difficult to generate Figure 1 a sharp reversal of the magnetization direction of the second magnetosensitive portion 122 such as the portion surrounded by the dashed line Ja, and thus no large Barkhausen jump is generated.

[0071] On the other hand, when the direction of the magnetic field changes as Figure 5 shown in (ii) of starting from the state shown in (2) of, the magnetization direction of the second magnetosensitive portion 122 does not change due to the influence of the first magnetosensitive portion 121 until a certain degree of magnetic field change. As Figure 5 shown in (3) and (4) of, at the portion surrounded by the dashed line Jb where the magnetic field change exceeds the threshold, the magnetization direction of the second magnetosensitive portion 122 is reversed all at once. Thereby, the magnetic flux density of the first magnetic member 120a changes sharply (that is, a large Barkhausen jump is generated), and electricity (a generation pulse) is generated in the coil 130 wound around the magnetic member composite 110. Figure 5

[0072] In a conventional magnetic member, as Figure 1 shown, in one reciprocating change in the direction of the magnetic field, large Barkhausen jumps are generated at two portions surrounded by the dashed line Ja and the dashed line Jb respectively, and two generation pulses are generated in the coil. Therefore, since the two generation pulses are caused by magnetic field changes in opposite directions, if the magnetization state of the magnetic member is shifted, the generated power of the two generation pulses also deviates. For example, when Figure 1 the magnitude of the magnetization of the hard magnetic portion in (2) of is different from Figure 1 the magnitude of the magnetization of the hard magnetic portion in (5) of, the change amount of the magnetic flux density in the large Barkhausen jump generates a difference between the portion surrounded by the dashed line Ja and the portion surrounded by the dashed line Jb.

[0073] ​In contrast, in the first magnetic member 120a, the first magnetosensitive portion 121 is fully magnetized and the magnetization direction does not change. Therefore, during one reciprocating change in the direction of the magnetic field, a large Barkhausen jump occurs at a portion surrounded by the dashed line Jb, and a primary power generation pulse is generated in the coil 130. Therefore, unlike conventional magnetic members, there is no deviation between the two power generation pulses generated during one reciprocating change in the direction of the magnetic field. Therefore, the deviation in the generated power of the power generation element 100 can be reduced. In addition, although when the first magnetosensitive portion 121 is not fully magnetized, there may be a region in the first magnetosensitive portion 121 that is difficult to be magnetized by an external magnetic field formed by the magnet 10 or the like, since the first magnetosensitive portion 121 is fully magnetized, this region is also magnetized, and the change in the magnetic flux density of the first magnetic member 120a in the large Barkhausen jump can be increased. Therefore, a stable power generation pulse can be generated based on the large Barkhausen jump of the first magnetic member 120a.

[0074] In addition, as Figure 6 shown, in the second magnetic member 120b, similarly to the first magnetic member 120a, the first magnetosensitive portion 121 is fully magnetized and the magnetization direction does not change. Therefore, during one reciprocating change in the direction of the magnetic field, a primary Barkhausen jump occurs, and a primary power generation pulse is generated in the coil 130. Therefore, for the same reason as the first magnetic member 120a, a stable power generation pulse can also be generated based on the large Barkhausen jump of the second magnetic member 120b. However, in the first magnetic member 120a, a large Barkhausen jump occurs at the portion surrounded by the dashed line Jb, whereas in the second magnetic member 120b, a large Barkhausen jump occurs at the portion surrounded by the dashed line Ja.

[0075] Specifically, when starting from the state where a magnetic field is applied to the second magnetic member 120b in the same direction as the magnetization direction of the first magnetosensitive portion 121 as shown in Figure 6 (1) and the direction of the magnetic field changes as shown in Figure 6 (i), the magnetization direction of the second magnetosensitive portion 122 does not change due to the influence of the first magnetosensitive portion 121 until a certain degree of change in the magnetic field. As shown in Figure 6 (2) and (3), at the portion surrounded by the dashed line Ja where the change in the magnetic field exceeds the threshold, the magnetization direction of the second magnetosensitive portion 122 suddenly reverses. As a result, the magnetic flux density of the second magnetic member 120b changes sharply (that is, a large Barkhausen jump occurs), and electric power (a power generation pulse) is generated in the coil 130 wound around the magnetic member composite 110. In this way, in Figure 5 (i) and Figure 6In (i) thereof, the direction of the magnetic field changes in the same manner, but no large Barkhausen jump occurs in the first magnetic member 120a. In contrast, a large Barkhausen jump occurs in the second magnetic member 120b.

[0076] In the second magnetic member 120b, as Figure 6 shown in (4) thereof, even when a magnetic field in a direction opposite to the magnetization direction of the first magnetosensitive portion 121 is applied, the magnetization direction of the first magnetosensitive portion 121 does not change. Therefore, the first magnetosensitive portion 121 and the second magnetosensitive portion 122 are magnetized in opposite directions. Thus, when the direction of the magnetic field changes as in Figure 6 (ii) thereof, as Figure 6 shown in (1) thereof, the magnetization direction of the second magnetosensitive portion 122 is reversed to be the same as the magnetization direction of the first magnetosensitive portion 121. In this case, it is difficult to cause a sharp reversal of the magnetization direction of the second magnetosensitive portion 122, so no large Barkhausen jump occurs. In this way, in Figure 5 (ii) thereof and Figure 6 (ii) thereof, the direction of the magnetic field changes in the same manner, but a large Barkhausen jump occurs in the first magnetic member 120a. In contrast, no large Barkhausen jump occurs in the second magnetic member 120b. As a result, in the first magnetic member 120a and the second magnetic member 120b, large Barkhausen jumps with stable changes in magnetic flux density are respectively generated once. Therefore, compared with conventional magnetic members, stable power generation can be performed, and a power generation element 100 with difficult deviation in power generation amount can be realized.

[0077] In addition, in the first magnetic member 120a and the second magnetic member 120b, only one large Barkhausen jump is respectively generated in one reciprocating change in the direction of the magnetic field. However, since the magnetization directions of the first magnetosensitive portions 121 in the first magnetic member 120a and the second magnetic member 120b are in opposite directions, as Figure 7 shown, the large Barkhausen jumps occur at different timings. Therefore, in the magnetic member complex 110, two large Barkhausen jumps are generated in one reciprocating change in the direction of the magnetic field, similar to the conventional magnetic member shown by Figure 1 .

[0078] [Regarding the influence of an external magnetic field]

[0079] Next, the influence of an external magnetic field in the case of generating power using the power generation element 100 according to the present embodiment will be described. Specifically, the results obtained by measuring the amount of power generation in the case where the magnitude of the external magnetic field is changed by changing the distance between the power generation element 100 and the magnet 10 will be described.

[0080] Figure 8It is a schematic diagram of a circuit used for measuring the magnitude of power generation of a power generation element. In measuring the magnitude of power generation of the power generation element 100, the power generation element 100 and the magnet 10 are arranged so as to have the positional relationship as shown in Figure 2 and Figure 3 , and the direction of the magnetic field from the magnet 10 applied to the power generation element 100 is repeatedly changed. At this time, the magnetic member 120 used is the magnetic member 120 obtained by magnetizing the first magnetosensitive portion 121 by applying a magnetic field of 5000 Oe. In addition, the power generation element 100 is connected to the circuit as shown in Figure 8 . Specifically, the output of the power generation element 100 is connected to a full-wave rectifier circuit connected to a capacitor C and a resistor R. The rectified voltage V of the power generation pulse of the power generation element 100 is measured every time the orientation of the external magnetic field is reversed, and the voltage V×time in the power generation pulse is set as the magnitude of power generation. The magnitude of power generation is measured 2500 times, and the average value and the minimum value of the 2500 measured magnitudes of power generation are derived.

[0081] In addition, regarding the distance between the magnet 10 and the magnetic member composite 110, the measurement is started based on the distance at which the magnitude of the magnetic field applied to the magnetic member composite 110 is 20 Oe. After that, when the magnet 10 is brought closer to the magnetic member composite 110 and the distance is shortened by 1 mm each time, it returns at the time point when the distance is shortened by 3 mm or 5 mm, and the distance is extended by 1 mm each time to return to the original distance. Hereinafter, the case where the measurement is performed under the condition of shortening the distance from the reference distance by 3 mm and returning is set as Measurement Example 1, and the case where the measurement is performed under the condition of shortening the distance from the reference distance by 5 mm and returning is set as Measurement Example 2. Since the magnitude of the magnetic field applied to the magnetic member composite 110 is determined according to the distance between the magnet 10 and the magnetic member composite 110, the shorter the distance, the larger the magnetic field applied to the magnetic member composite 110. Therefore, it can also be said that in Measurement Example 1 and Measurement Example 2, while performing the operation of gradually increasing the magnetic field applied to the magnetic member composite 110 to a specified magnitude and then returning to the original magnetic field magnitude, the magnitude of power generation is measured.

[0082] Figure 9 It is a diagram showing the measurement result of the magnitude of power generation of the power generation element 100 in Measurement Example 1. Figure 10 It is a diagram showing the measurement result of the magnitude of power generation of the power generation element 100 in Measurement Example 2. In Figure 9 and Figure 10 , the horizontal axis represents the difference in the distance between the magnet 10 and the magnetic member composite 110 with respect to the reference distance. In Figure 9 and Figure 10In [the figure], the vertical axis represents the magnitude of the generated electricity measured by the above-described method. Additionally, E1 on this vertical axis is the magnitude of the generated electricity for the target where an electrical signal can be stably detected. Additionally, in Figure 9 and Figure 10 , the circular markers represent the average value of the magnitude of the generated electricity, and the triangular markers represent the minimum value of the magnitude of the generated electricity. Additionally, in Figure 9 and Figure 10 , the markers connected by solid lines represent the measurement results until the distance is shortened and then returned, and the markers connected by dashed lines represent the measurement results after the return. Furthermore, in Figure 9 and Figure 10 , the unit of the magnitude of the generated electricity is an arbitrary unit (a.u.).

[0083] As Figure 9 and Figure 10 show, it can be seen that: in either Measurement Example 1 or Measurement Example 2, before the distance between the magnet 10 and the magnetic member complex 110 is brought close and then returned (the markers connected by solid lines), there is almost no difference between the average value (circular markers) and the minimum value (triangular markers) of the magnitude of the generated electricity, and the deviation of the generated electricity of the power generation element 100 is small. Additionally, the magnitude of the generated electricity is not lower than E1. This is considered to be because, as described above, in one reciprocating change in the direction of the magnetic field, each magnetic member 120 generates one Barkhausen jump instead of generating two Barkhausen jumps as in the past, thereby stabilizing the power generation.

[0084] Additionally, as Figure 9 shows, in Measurement Example 1 where the distance between the magnet 10 and the magnetic member complex 110 is shortened by 3 mm from the reference distance and then returned, after the distance between the magnet 10 and the magnetic member complex 110 is shortened and then returned (the markers connected by dashed lines), there is also almost no difference between the average value (circular markers) and the minimum value (triangular markers) of the magnitude of the generated electricity, and there is almost no difference in the magnitude of the generated electricity before and after the return. When the distance between the magnet 10 and the magnetic member complex 110 is 3 mm shorter than the reference distance, the magnitude of the magnetic field applied to the magnetic member complex 110 is 60 Oe. Therefore, when the magnitude of the magnetic field applied to the magnetic member complex 110 is 20 Oe or more and 60 Oe or less, the power generation element 100 can generate electricity stably even if the magnitude of the magnetic field changes.

[0085] On the other hand, as Figure 10As shown, in Measurement Example 2 where the distance between the magnet 10 and the magnetic member composite 110 is shortened by 5 mm from the reference distance and then returned, after shortening the distance between the magnet 10 and the magnetic member composite 110 and then returning (the marks connected by the dashed line), the smaller the magnitude of the magnetic field, the greater the difference between the average value (circular mark) and the minimum value (triangular mark) of the magnitude of power generation, and there is a deviation in the power generation amount of the power generation element 100. In addition, after shortening the distance between the magnet 10 and the magnetic member composite 110 and then returning (the marks connected by the dashed line), the magnitude of power generation is lower compared to before returning (the marks connected by the solid line). This is considered to be because when a magnetic field above a specified magnitude is applied to the magnetic member 120 of the magnetic member composite 110, the magnetization state of the first magnetosensitive portion 121 that is magnetized changes, and the magnitude and stability of power generation of the power generation element 100 decrease under the condition of a smaller magnetic field. However, the power generation element 100 can still be used under the condition of applying a magnetic field of 60 Oe or more to the magnetic member composite 110. For example, in an environment of a constant external magnetic field, power generation can be stably performed. In addition, by increasing the magnetic field applied when magnetizing the first magnetosensitive portion 121, it is also possible to make it difficult for the magnetization state of the first magnetosensitive portion 121 to change.

[0086] In addition, by manufacturing the power generation element 100 using the magnetic member 120 that is easy to stabilize the magnetization state of the first magnetosensitive portion 121, the range of the external magnetic field in which the power generation element 100 can operate stably can be increased. As a method for stabilizing the magnetization state of the first magnetosensitive portion 121 of the magnetic member 120, for example, there can be cited (1) a method of extending the length of the magnetic member 120, and (2) a method of increasing the coercive force of the magnetic member 120 (the first magnetosensitive portion 121), etc.

[0087] In the method of (1), since the length of the magnetic member 120 becomes longer, the influence caused by the reverse magnetic field of the magnetic member 120 to which an external magnetic field is applied becomes smaller. As a result, the magnetization state of the first magnetosensitive portion 121 is stabilized. For example, by making the length of the magnetic member 120 7 mm or more, the magnetization state of the first magnetosensitive portion 121 is easily stabilized. By making the length of the magnetic member 120 7 mm or more, the reverse magnetic field coefficient is easily 0.01 or less. In addition, since the reverse magnetic field coefficient also changes according to the thickness of the magnetic member 120, the length of the magnetic member 120 can also be set as follows: the reverse magnetic field coefficient is 0.01 or less according to the thickness of the magnetic member 120.

[0088] In addition, in the method of (2), by increasing the coercive force of the magnetic member 120 (the first magnetosensitive portion 121), even if the external magnetic field becomes larger, it is difficult for the magnetization state of the first magnetosensitive portion 121 to change.

[0089] For example, in the manufacture of the power generation element 100, an external magnetic field of the same magnitude as the environment in which the power generation element 100 operates is applied to the magnetic member composite 110 produced under specified conditions. If the magnetization state of the first magnetosensitive portion 121 does not change due to the application of the external magnetic field, the power generation element 100 is manufactured using the magnetic member composite 110 in this state. On the other hand, in the case where the magnetization state of the first magnetosensitive portion 121 changes due to the application of the external magnetic field, the power generation element 100 is manufactured using the magnetic member composite 110 remade by applying the above method (1) or (2). In the determination of the change in the magnetization state of the first magnetosensitive portion 121, the magnitude of the power generation of the power generation element 100 can be measured as described above, or the BH curve of the magnetic member composite 110 or the magnetic member 120 can be measured. By such a method, a power generation element 100 that can generate power more stably can be manufactured.

[0090] [Configuration of Magnetic Members]

[0091] Next, the configuration of the plurality of magnetic members 120 in the magnetic member composite 110 will be described. Figure 11 is a diagram for explaining the configuration of the plurality of magnetic members 120 in the magnetic member composite 110. Specifically, in Figure 11 examples of the configurations of the first magnetic member 120a and the second magnetic member 120b are shown in the cases where the number of magnetic members 120 is 2, 4, 6, and 8. In addition, in Figure 11 the configurations of the first magnetic member 120a and the second magnetic member 120b are shown when observing the plurality of magnetic members 120 along the winding axis direction. In addition, in Figure 11 in order to distinguish the first magnetic member 120a and the second magnetic member 120b, the second magnetic member 120b is marked with a dotted pattern. In addition, in Figure 11 the more to the left the configuration shown, the better the power generation stability of the power generation element 100.

[0092] As Figure 11 shown, for example, when observing along the winding axis direction, the plurality of magnetic members 120 are arranged in a matrix with the direction away from the magnet 10 for forming the external magnetic field as the column direction. In addition, one of the rows and columns of the plurality of magnetic members 120 can also be one. That is, the plurality of magnetic members 120 can also be arranged in a line.

[0093] In addition, as Figure 11As shown, when a plurality of magnetic members 120 are arranged such that the first magnetic member 120a and the second magnetic member 120b are alternately arranged (for example, the arrangement of two examples from the left when the number of magnetic members 120 is 4 or more), the power generation stability of the power generation element 100 is better. This is because the repulsion between the magnetic poles of the first magnetosensitive portions 121 magnetized in opposite directions in the first magnetic member 120a and the second magnetic member 120b is suppressed, and the magnetization state of the first magnetosensitive portion 121 is stabilized. In this case, for example, in all combinations of two adjacent magnetic members 120 among the plurality of magnetic members 120, one magnetic member 120 is the first magnetic member 120a and the other magnetic member 120 is the second magnetic member 120b. Among the plurality of magnetic members 120, for example, in either the row direction or the column direction, the first magnetic members 120a are not adjacent to each other, and the second magnetic members 120b are not adjacent to each other.

[0094] In addition, as Figure 11 shown, when there are a plurality of the first magnetic members 120a and a plurality of the second magnetic members 120b (when the number of magnetic members 120 is 4 or more), the power generation stability of the power generation element 100 is better when the number of each of the first magnetic members 120a and the second magnetic members 120b is even than when it is odd. This is because it becomes easier to maintain the symmetry of the magnetization state of the entire magnetic member complex 110 with a plurality of magnetic members 120.

[0095] In addition, as Figure 11 shown, when the number of magnetic members 120 arranged in the column direction (the direction away from the magnet 10) is less than or equal to the number of magnetic members 120 arranged in the row direction, the power generation stability of the power generation element 100 is better. This is because when the number of magnetic members 120 arranged in the direction away from the magnet 10 is small (not exceeding the number of magnetic members 120 arranged in the row direction), it is difficult to generate a difference in the magnitude of the magnetic fields applied by the plurality of magnetic members 120. In addition, the number of magnetic members 120 arranged in the column direction may be less than the number of magnetic members 120 arranged in the row direction.

[0096] [Summary]

[0097] As described above, the power generation element according to the first aspect of the present disclosure includes: a magnetic member complex 110 having a plurality of magnetic members 120, wherein the plurality of magnetic members 120 are bundled into a bundle, and each of the plurality of magnetic members 120 generates a large Barkhausen effect according to a change in an external magnetic field; and a coil 130 wound around the magnetic member complex 110. Each of the plurality of magnetic members 120 has a first magnetosensitive portion 121 and a second magnetosensitive portion 122, and the second magnetosensitive portion 122 is softer magnetic than the first magnetosensitive portion 121. The first magnetosensitive portion 121 is magnetized along the winding axis direction of the coil 130, and the magnetization direction does not change according to the change in the direction of the external magnetic field. The plurality of magnetic members 120 include a first magnetic member 120a in which the first magnetosensitive portion 121 is magnetized in a first direction and a second magnetic member 120b in which the first magnetosensitive portion 121 is magnetized in a second direction opposite to the first direction.

[0098] In this way, the first magnetosensitive portion 121 of the magnetic member 120 included in the magnetic member complex 110 is magnetized, and thus, the magnetization direction of the first magnetosensitive portion 121 is constant and does not depend on the direction of the external magnetic field. As a result, even in one reciprocating change in the direction of the external magnetic field, since the magnetization direction of the second magnetosensitive portion 122 suddenly changes to the opposite direction to the magnetization direction of the first magnetosensitive portion 121, the generated large Barkhausen jump is one time. Therefore, the following situation does not occur: as in the conventional magnetic member, in one reciprocating change in the direction of the external magnetic field, the magnetization state of the first magnetosensitive portion 121 differs in each of the two large Barkhausen jumps, and the magnitude of the generated power pulse deviates. As a result, the magnitude of the power pulse generated in the coil 130 due to the large Barkhausen jump is stabilized. Therefore, a power generation element capable of reducing the deviation of the generated power can be realized. In addition, since the plurality of magnetic members 120 of the magnetic member complex 110 include the first magnetic member 120a and the second magnetic member 120b in which the magnetization directions of the first magnetosensitive portions 121 are opposite to each other, as the magnetic member complex 110, two large Barkhausen jumps can be performed in one reciprocating change in the direction of the external magnetic field, and the number of power generations of the power generation element can also be maintained the same as in the case of using the conventional magnetic member.

[0099] The power generation element according to the second aspect of the present disclosure is the power generation element according to the first aspect, and the plurality of magnetic members 120 include a plurality of first magnetic members 120a and a plurality of second magnetic members 120b.

[0100] Thereby, the change in the magnetic flux density in the large Barkhausen jump can be increased. Therefore, the power generation element can increase the generated power and generate power more stably.

[0101] The power generation element according to the third aspect of the present disclosure is such that, based on the power generation element according to the second aspect, a plurality of magnetic members 120 are arranged such that the first magnetic member 120a and the second magnetic member 120b are alternately arranged.

[0102] Thereby, the repulsion between the magnetic poles of the first magnetosensitive portions 121 magnetized in opposite directions in the first magnetic member 120a and the second magnetic member 120b is suppressed, and the magnetization state of the first magnetosensitive portions 121 is stabilized. Therefore, the power generation element can generate electricity more stably.

[0103] The power generation element according to the fourth aspect of the present disclosure is such that, based on the power generation element according to the second or third aspect, the number of each of the first magnetic member 120a and the second magnetic member 120b is an even number.

[0104] Thereby, it becomes easy to arrange a plurality of magnetic members 120 that can easily maintain the symmetry of the magnetization state of the entire magnetic member complex 110. Therefore, the power generation element can generate electricity more stably.

[0105] The power generation element according to the fifth aspect of the present disclosure is such that, based on the power generation element according to any one of the second to fourth aspects, when viewed along the winding axis direction, a plurality of magnetic members 120 are arranged in a matrix shape with the direction away from the magnet 10 for forming an external magnetic field as the column direction, and among the plurality of magnetic members 120, the number of magnetic members 120 arranged in the column direction is less than or equal to the number of magnetic members 120 arranged in the row direction.

[0106] Thereby, the number of magnetic members 120 arranged in the direction away from the magnet 10 is small (not exceeding the number of magnetic members 120 arranged in the row direction), and it is difficult for the magnitudes of the magnetic fields applied by the plurality of magnetic members 120 to differ from each other. Therefore, the power generation element can generate electricity more stably.

[0107] The power generation element according to the sixth aspect of the present disclosure is such that, based on the power generation element according to any one of the first to fifth aspects, it does not include a ferrite bead disposed at an end of the magnetic member complex 110 in the winding axis direction.

[0108] Thereby, miniaturization and cost reduction of the power generation element can be achieved.

[0109] The power generation system according to the seventh aspect of the present disclosure includes: a power generation element according to any one of the first to sixth aspects; and a magnet 10 that applies a magnetic field to the power generation element and repeatedly reverses the orientation of the magnetic field applied to the power generation element. The power generation element generates electricity due to the reversal of the orientation of the magnetic field applied by the magnet 10.

[0110] Thus, due to the above-described power generation element, a power generation system capable of reducing the deviation of the power generation amount can be realized.

[0111] In the power generation system according to the eighth aspect of the present disclosure, based on the power generation system according to the seventh aspect, the magnitude of the magnetic field applied to the magnetic member composite 110 of the above-described power generation element is 20 Oe or more and 60 Oe or less.

[0112] Thus, the magnetization state of the first magnetosensitive portion 121 is difficult to be affected by the applied magnetic field. Therefore, the power generation element can generate power more stably.

[0113] In addition, the encoder according to the ninth aspect of the present disclosure includes the power generation system according to the seventh aspect or the eighth aspect. The above-described power generation element outputs electric power generated due to the reversal of the direction of the magnetic field applied by the magnet 10.

[0114] Thus, by outputting the electric power of the above-described power generation element capable of reducing the deviation of the power generation amount, the detection accuracy of the encoder can be improved.

[0115] (Other Embodiments)

[0116] As described above, the power generation element, the power generation system, and the encoder according to the present disclosure have been described based on the embodiments. However, the present disclosure is not limited to the above-described embodiments. Modes obtained by applying various modifications conceived by those skilled in the art to the above-described embodiments and modes realized by arbitrarily combining the constituent elements and functions in the embodiments without departing from the gist of the present disclosure are also included in the present disclosure.

[0117] In the above-described embodiment, the power generation element 100 does not include a ferrite bead, but is not limited thereto. The power generation element 100 may also include a ferrite bead at the end of the magnetic member composite 110 to improve the magnetic flux concentration from the magnet 10.

[0118] In addition, in the above-described embodiment, the power generation element 100 includes the magnetic member composite 110 obtained by bundling a plurality of magnetic members 120 into a bundle, but is not limited thereto. In the case of applications where the number of power generation times in the change of the magnetic field direction in one reciprocation can be reduced, the power generation element 100 may also include one magnetic member 120 instead of the magnetic member composite 110. For example, the number of power generation times of the power generation element 100 can also be increased by increasing the number of magnetic poles of the magnet 10 that rotates together with the rotation shaft 30.

[0119] In addition, in the above-described embodiment, the position of the power generation element 100 is fixed, and the magnet 10 rotates due to the rotation of the rotation shaft 30, whereby the orientation of the magnetic field applied to the power generation element 100 is repeatedly reversed. However, the present invention is not limited thereto. It is also possible that the position of the magnet 10 is fixed, and the power generation element 100 rotates due to the rotation of the rotation shaft 30, whereby the orientation of the magnetic field applied to the power generation element 100 is repeatedly reversed.

[0120] In addition, for example, in the above-described embodiment, a rotary encoder used in combination with a motor has been described as an example. However, the present invention is not limited thereto. The technology of the present disclosure can also be applied to a linear encoder.

[0121] Industrial Applicability

[0122] The power generation element, power generation system, and encoder according to the present disclosure are useful for devices and apparatuses such as motors that rotate or linearly move.

[0123] Description of Reference Numerals

[0124] 1: Encoder; 5: Power generation system; 10: Magnet; 20: Rotating plate; 30: Rotation shaft; 40: Substrate; 50: Control circuit; 60: Memory; 100: Power generation element; 110: Magnetic member complex; 120: Magnetic member; 120a: First magnetic member; 120b: Second magnetic member; 121: First magnetosensitive portion; 122: Second magnetosensitive portion; 130: Coil; 181, 182: Terminals; 190: Housing.

Claims

1. A power generation element, comprising: A magnetic member complex having a plurality of magnetic members, wherein the plurality of magnetic members are bundled into a bundle, and each of the plurality of magnetic members generates a large Barkhausen effect according to a change in an external magnetic field; and A coil wound around the magnetic member complex, wherein, Each of the plurality of magnetic members has a first magnetosensitive portion and a second magnetosensitive portion, and the second magnetosensitive portion is softer magnetic than the first magnetosensitive portion, The first magnetosensitive portion is magnetized along the winding axis direction of the coil, and the magnetization direction does not change according to a change in the direction of the external magnetic field, The plurality of magnetic members include a first magnetic member in which the first magnetosensitive portion is magnetized in a first direction and a second magnetic member in which the first magnetosensitive portion is magnetized in a second direction opposite to the first direction.

2. The power generation element according to claim 1, wherein, The plurality of magnetic members include a plurality of each of the first magnetic member and the second magnetic member.

3. The power generation element according to claim 2, wherein, The plurality of magnetic members are arranged such that the first magnetic member and the second magnetic member are alternately arranged.

4. The power generation element according to claim 2, wherein, The number of each of the first magnetic member and the second magnetic member is an even number.

5. The power generation element according to claim 2, wherein, When viewed along the winding axis direction, the plurality of magnetic members are arranged in a matrix shape with the direction away from the magnetic field generation source for forming the external magnetic field as the column direction, Among the plurality of magnetic members, the number of magnetic members arranged in the column direction is less than or equal to the number of magnetic members arranged in the row direction.

6. The power generation element according to claim 1, wherein, It does not have a ferrite bead, and the ferrite bead is arranged at an end of the magnetic member complex in the winding axis direction.

7. A power generation system, comprising: The power generation element according to any one of claims 1 to 6; and A magnetic field application unit that applies a magnetic field to the power generation element and repeatedly reverses the orientation of the magnetic field applied to the power generation element, wherein, The power generation element generates electricity due to the reversal of the orientation of the magnetic field applied by the magnetic field application unit.

8. The power generation system according to claim 7, wherein, The magnitude of the magnetic field applied to the magnetic member complex of the power generation element is 20 Oe or more and 60 Oe or less.

9. An encoder, wherein, It includes the power generation system according to claim 7, wherein the power generation element outputs electricity generated due to the reversal of the orientation of the magnetic field applied by the magnetic field application unit.

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