POWER GENERATION ELEMENT, POWER GENERATION SYSTEM AND ENCODER

Abstract

A power generation element or the like is provided that can reduce fluctuations in power generation. The power generation element (100) comprises: a magnetic element assembly (110) including a plurality of magnetic elements (120) that are bundled together and each of which exhibits the strong Barkhausen effect due to a change in an external magnetic field; and a coil (130) wound on the magnetic element assembly (110). Each of the plurality of magnetic elements (120) includes a first magnetosensitive part (121) and a second magnetosensitive part (122) that is magnetically softer than the first magnetosensitive part (121). The first magnetosensitive part (121) is magnetized in the direction of the winding axis of the coil (130), and the direction of magnetization of the first magnetosensitive part (121) does not change due to a change in the direction of the external magnetic field.The plurality of magnetic elements (120) comprise: a first magnetic element (120a) in which the first magnetosensitive part (121) is magnetized in a first direction; and a second magnetic element (120b) in which the first magnetosensitive part (121) is magnetized in a second direction opposite to the first direction.

Description

Technical area

[0001] The present disclosure relates to power generation elements, power generation systems, and encoders, and more particularly to a power generation element utilizing the strong Barkhausen effect, and a power generation system and an encoder each including the power generation element. State of the art

[0002] Among rotary encoders that detect the rotation, etc., of a motor, a conventionally known encoder includes a power generation element that utilizes the strong Barkhausen effect to detect rotation without using a battery (e.g., Patent Literature (PTL) 1). Such a power generation element has a configuration in which a coil is wound on a magnetic element that exhibits, for example, the strong Barkhausen effect. The magnetic element exhibiting the strong Barkhausen effect has a magnetic flux density that changes abruptly due to a change in an external magnetic field, and therefore, a rapid change in the magnetic flux density causes electric current to be generated in the coil wound on the magnetic element. The encoder detects the rotation, etc., of a motor using an electrical signal based on such electrical energy. Citation listPatent literature

[0003] PTL 1: Unexamined Japanese Patent Publication No. 2012-198067 Summary of the inventionTechnical problem

[0004] If the electric power generated by the power generation element in the encoder described above fluctuates greatly, the rotation, etc. of the motor cannot be accurately detected.

[0005] The present disclosure has been developed to solve this problem, and an object of the present disclosure is to provide a power generation element capable of reducing fluctuations in the amount of power generation, and a power generation system and an encoder each including the power generation element.

[0006] A power generation element according to one aspect of the present disclosure includes: a magnetic element assembly including a plurality of magnetic elements bundled together, each of which exhibits a strong Barkhausen effect due to a change in an external magnetic field; and a coil wound on the magnetic element assembly. Each of the plurality of magnetic elements includes a first magnetosensitive part and a second magnetosensitive part that is magnetically softer than the first magnetosensitive part. The first magnetosensitive part is magnetized in a winding axis direction of the coil, and a magnetization direction of the first magnetosensitive part does not change due to a change in a direction of the external magnetic field.The plurality of magnetic elements comprise a first magnetic element in which the first magnetosensitive part is magnetized in a first direction and a second magnetic element in which the first magnetosensitive part is magnetized in a second direction opposite to the first direction.

[0007] Furthermore, a power generation system according to another aspect of the present disclosure includes: the power generation element described above; and a magnetic field applying part that applies a magnetic field to the power generation element and repeatedly causes a reversal of a direction of the magnetic field applied to the power generation element. The power generation element generates electric power by the reversal of the direction of the magnetic field caused by the magnetic field applying part.

[0008] Furthermore, according to another aspect of the present disclosure, an encoder includes the power generation system described above. The power generation element outputs the electric current generated by the reversal of the direction of the magnetic field caused by the magnetic field application part.

[0009] According to the present disclosure, it is possible to provide a power generation element capable of reducing fluctuations in the amount of power generation, and a power generation system and an encoder each including the power generation element. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a graph showing an example of a simplified BH curve of a magnetic element exhibiting the strong Barkhausen effect. [ Fig. 2] Fig. 2 is a cross-sectional view showing a schematic configuration of an encoder according to an exemplary embodiment. [ Fig. 3] Fig. 3 is a top view of a magnet in an encoder according to an exemplary embodiment. [ Fig. 4] Fig. 4 is a cross-sectional view showing a schematic configuration of a power generation element according to an exemplary embodiment. [ Fig. 5] Fig. 5 is a diagram showing an example of a simplified BH curve of a first magnetic element according to an exemplary embodiment. [ Fig. 6] Fig. 6 is a diagram showing an example of a simplified BH curve of a second magnetic element according to an exemplary embodiment. [ Fig. 7] Fig. 7 is a diagram showing the BH curve of the first magnetic element of Fig. 5 and the BH curve of the second magnetic element from Fig. 6 are placed on top of each other. [ Fig. 8] Fig. Figure 8 is a schematic diagram showing a circuit for measuring the electrical energy generated by a power generating element. [ Fig. 9] Fig. 9 is a graph showing the result of measuring the value of electric power generated by a power generation element in Measurement Example 1. [ Fig. 10] Fig. 10 is a graph showing the result of measuring the value of electric power generated by a power generation element in Measurement Example 2. [ Fig. 11] Fig. 11 is a diagram for describing the arrangement of a plurality of magnetic elements in a magnetic element assembly according to an exemplary embodiment. Description of Embodiments (Circumstances leading to an aspect of the present disclosure)

[0010] As the above-described magnetic element exhibiting the strong Barkhausen effect, for example, a composite magnetic wire is used that has different magnetic properties in a central region and an outer peripheral region defined in the radial direction, such as a Wiegand wire. In the Wiegand wire, either the central region or the outer peripheral region has a soft magnetic property, and the other has a hard magnetic property.

[0011] Next, the strong Barkhausen effect is explained. Fig. Figure 1 is a diagram showing an example of a simplified BH curve of a magnetic element exhibiting the strong Barkhausen effect. Fig. 1 shows an example in which a composite magnetic wire, which is magnetically softer in an outer peripheral region than in a central region, is used as a magnetic element. Fig. Figure 1 is a diagram illustrating a situation where the direction of an applied magnetic field changes in the longitudinal direction of the wire. In (1) to (6) in Fig. 1, magnetic elements are schematically shown with arrows indicating magnetization directions. The dashed arrow indicates the magnetization direction of the outer peripheral region with a soft magnetic property, and the solid arrow indicates the magnetization direction of the central region with a hard magnetic property. Note that in Fig. 1 the arrow indicating a magnetization direction indicates only one magnetization direction, which means that regardless of the magnetization degrees, the magnetization directions are indicated by arrows of the same size.

[0012] When a magnetic field having a strength greater than or equal to a predetermined strength is applied to a magnetic element in the longitudinal direction of the magnetic element, the central portion and the outer peripheral portion of the magnetic element are magnetized in the same direction as in (1) in Fig. 1. Even if the direction of the magnetic field changes, as in (i) in Fig. As shown in Figure 1, the magnetization direction of the outer peripheral region, which has a soft magnetic property, does not change due to the effects of the central region, which has a hard magnetic property, until the magnetic field changes to a certain extent. In the region surrounded by the dashed line Ja, where the magnetic field change exceeds a threshold value, the magnetization direction of the outer peripheral region with a soft magnetic property quickly reverses, as shown in (2) and (3) in Fig. 1. This phenomenon is also called a strong Barkhausen jump. As a result, the magnetic flux density of the magnetic element changes abruptly, leading to the generation of electric current (current generation pulse) in the coil wound on the magnetic element. A further change in the magnetic field leads to the reversal of the magnetization direction of the central region, as shown in (4). Fig. 1, which means that the magnetic element is in the opposite direction as in (1) in Fig. 1. In this case, the direction of the magnetic field changes, as in (ii) in Fig. 1, and in the area surrounded by the dashed line Jb, where the change in the magnetic field exceeds a threshold value, the direction of the magnetization of the outer edge region reverses rapidly, as shown in (5) and (6) in Fig. 1. 1. As a result, the magnetic flux density of the magnetic element changes abruptly, resulting in further generation of electric current (current generation pulse) in the coil wound on the magnetic element. This current generation pulse is detected, and thus the current generation element can be used for the encoder. In the Fig. In the example shown in Figure 1, the direction of magnetization of the magnetic element is reversed twice due to a stroke change in the direction of the magnetic field, and therefore two current generation pulses are generated.

[0013] In a power generation element with such a magnetic element, the electrical energy generated by the power generation pulses may vary if the power generation pulse is repeatedly detected. For example, detecting 5,000 power generation pulses may result in the detection of a power generation pulse with an electrical energy that differs from the average of the generated electrical energy by more than or equal to 10 times the standard deviation (i.e., 10 σ).

[0014] In view of this problem, an object of the present disclosure is to provide a power generation element capable of reducing fluctuations in the amount of power generation, and a power generation system and an encoder each including the power generation element.

[0015] Hereinafter, an exemplary embodiment of the present disclosure will be described with reference to the drawings. Note that each exemplary embodiment described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, structural elements, arrangement and connection of the structural elements, etc. shown in the following exemplary embodiment are merely examples and are not intended to limit the present disclosure. Therefore, among the structural elements in the following exemplary embodiment, structural elements not listed in any of the independent claims of the present disclosure are described as optional structural elements.

[0016] Please note that the figures are schematic representations and are not necessarily precise. Therefore, scale reductions and the like are not necessarily the same throughout the figures. Furthermore, substantially identical elements are designated by the same reference numerals throughout the figures, and overlapping descriptions are omitted or simplified.

[0017] Furthermore, in this specification, terms that indicate the relationship between elements, such as being parallel, terms that indicate the shape of elements, such as a rectangle, and numerical ranges are not expressions that refer only to exact meanings, but expressions that refer to substantially equivalent ranges, encompassing, for example, approximately a few percent differences. <Beispielhafte Ausführungsform>

[0018] The following describes the encoder 1, the power generation system 5 and the power generation element 100 according to an exemplary embodiment. [Configuration]

[0019] First, the configurations of the encoder 1, the power generation system 5, and the power generation element 100 according to the present exemplary embodiment will be described.

[0020] Fig. 2 is a cross-sectional view illustrating a schematic configuration of the encoder 1 according to the present exemplary embodiment. Fig. Fig. 3 is a plan view of the magnet 10 in the encoder 1 according to the present exemplary embodiment. Note that in Fig. 2, the magnetic element assembly 110 and the coil 130, which are housed in the housing 190 of the power generating element 100, are schematically indicated by dashed lines. For reasons of clarity, Fig. 3, elements other than the magnet 10, the rotary shaft 30, and the magnetic element assembly 110 and the coil 130 included in the power generating element 100 are not shown.

[0021] The Fig. The encoder 1 shown in Figure 2 is, for example, a rotary encoder that can be used in combination with a motor, such as a servo motor. The encoder 1 is, for example, an absolute encoder of the power generation type. The encoder 1 detects the rotation angle, the amount of rotation, the number of revolutions, etc., of the rotary shaft 30 of a motor or the like, for example, based on electrical signals generated by the power generation element 100. The encoder 1 includes: a power generation system 5 including a magnet 10, a rotary plate 20, a substrate 40, and a power generation element 100; a control circuit 50; and a memory 60.In the encoder 1, the power generation element 100 included in the power generation system 5 generates electric power due to a change in the magnetic field formed by the magnet 10 caused by the rotation of the magnet 10, and outputs the generated electric power as electrical signals.

[0022] The rotary plate 20 is a plate-shaped member that rotates together with the rotary shaft 30, which is a driving part of a motor or the like. A central portion of a main surface of the rotary plate 20 is fixed to an end portion of the rotary shaft 30 located in the axial direction of the rotary shaft 30 (the direction in which the rotary shaft 30 extends). The rotary plate 20 extends in a direction perpendicular to the axial direction of the rotary shaft 30. The rotary plate 20 rotates about the rotation axis A, which passes through the center of the rotary shaft 30 and extends in the axial direction of the rotary shaft 30. The rotational movement of the rotary shaft 30 is synchronized with the rotational movement of a rotating device. The rotary plate 20 has a circular shape, for example, in plan view. The rotary plate 20 is made of, for example, metal, resin, glass, ceramic, or the like.

[0023] The rotating shaft 30 has the shape of a rod, e.g., a circular cylinder. The core of the rotating shaft 30 and the line of the rotation axis A coincide.

[0024] Magnet 10 is an example of the magnetic field applying part that applies an external magnetic field to the power generation element 100. Magnet 10 can be said to be a magnetic field source that provides an external magnetic field to the power generation element 100. Magnet 10 repeatedly reverses the direction of the magnetic field applied to the power generation element 100. Magnet 10 is, for example, a plate-shaped magnet. Magnet 10 faces the rotating plate 20 and is located on a main surface of the rotating plate 20 that is on the opposite side of the rotating shaft 30. In the present exemplary 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 and the thickness direction of the magnet 10 are the same and correspond to the axial direction of the rotating shaft 30.The magnet pair 10 rotates together with the rotary plate 20 around the rotary shaft 30 as the rotation center (in other words, around the rotation axis line A as the rotation axis). As the rotary shaft 30 rotates, the magnet pair 10 rotates, and thus the relative positioning between the magnet pair 10 and the power generation element 100 changes, and the magnetic field of the magnet pair 10 acting on the power generation element 100 also changes. For example, the rotation direction of the magnet pair 10 is both clockwise and counterclockwise, but it may also be only one of clockwise and counterclockwise.

[0025] The magnet pair 10 is sandwiched between the rotation axis line A of the rotating shaft 30 and spaced apart from each other on the same main surface of the rotating plate 20. In other words, the rotation axis A of the rotating shaft 30 is located between the magnet pair 10, and a gap is formed between them. Furthermore, the magnet pair 10 is arranged symmetrically with respect to the rotation axis A. The magnet pair 10 has the same shape.

[0026] The pair of magnets 10 is arranged in the rotation direction of the rotating shaft 30. Each of the two magnets 10 has an arc shape extending in the rotation direction of the rotating shaft 30 in plan view. Note that only one of the two magnets 10 can be located on the main surface of the rotating plate 20. Furthermore, the magnet 10 can be a magnet of any shape, such as a donut-shaped, disc-shaped, or bar-shaped magnet, as long as the magnet 10 can change the magnetic field to be applied to the power generation element 100. The magnet 10 is, for example, a permanent magnet, but may also be an electromagnet.

[0027] The north pole and south pole of each of the magnet pair 10 are arranged in a direction in which the magnet pair 10 is arranged. The arrangements of the north pole and south pole of the magnet pair 10 are the same. In other words, each of the magnet pair 10 is polarized in a direction in which the magnet pair 10 is arranged. Therefore, each of the magnet pair 10 generates a magnetic field in a direction in which the magnet pair 10 is arranged.

[0028] The south pole of one of the magnet pair 10 is positioned opposite the rotation axis line A, and the north pole of the other of the magnet pair 10 is positioned opposite the rotation axis line A. Therefore, when the magnet pair 10 changes position due to the rotation of the magnet pair 10 by the rotating shaft 30, the direction of the magnetic field formed by the magnet pair 10 reverses. The rotation of the magnet pair 10 causes a change in the magnetic field applied to the power generation element 100. Specifically, the direction of the magnetic field applied to the power generation element 100 is repeatedly reversed as the magnet pair 10 rotates.

[0029] The substrate 40 is located opposite a surface of the rotary plate 20 on which the magnet 10 is arranged, and is spaced apart from the rotary plate 20 and the magnet 10. In other words, the rotary shaft 30, the rotary plate 20, the magnet 10, and the substrate 40 are arranged in this order in the axial direction of the rotary 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 whose thickness direction is the axial direction of the rotary shaft 30. The substrate 40 has a circular shape, for example, in plan view. Viewed in the axial direction of the rotary shaft 30, the centers of the rotary shaft 30, the rotary plate 20, and the substrate 40 coincide at the position of the rotation axis line A.

[0030] Electronic components such as the power generation element 100, the control circuit 50, and the memory 60 are mounted on the substrate 40, which is, for example, a printed circuit board. Fig. In the example shown in Figure 2, the control circuit 50 and the memory 60 are mounted on a main surface of the substrate 40 facing the magnet 10, and the power generating element 100 is mounted on a main surface of the substrate 40 opposite the main surface facing the magnet 10. The substrate 40 is fixed, for example, to a housing that constitutes a part of the encoder 1, a motor, or the like.

[0031] The power generation element 100 is located on the main surface of the substrate 40 opposite the main surface facing the magnet 10. Therefore, the substrate 40 is arranged in the same direction as the magnet 10 when viewed from the power generation element 100. The power generation element 100 is arranged together with the magnet 10 and the rotary plate 20 in the axial direction of the rotating shaft 30. Hereinafter, the direction indicated by arrow Z in which the magnet 10, the rotary plate 20, and the power generation element 100 are arranged may be referred to as the arrangement direction. In the present exemplary embodiment, the arrangement direction is parallel to the axial direction of the rotating shaft 30 and parallel to a 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.

[0032] The power generation element 100 is arranged beyond the substrate 40 in the axial direction of the rotating shaft 30, as viewed from the rotating plate 20. Viewed in the axial direction of the rotating shaft 30, the power generation element 100 does not overlap the rotation axis line A and is offset from the rotation axis line A. Viewed in the axial direction of the rotating shaft 30, the power generation element 100 overlaps a point through which the rotating magnet 10 passes. The power generation element 100 extends along the main surface of the substrate 40 so that it extends along a tangent to the rotation direction of the magnet 10.

[0033] The power generation element 100 generates electric power due to a change in the magnetic field formed by the magnet 10, specifically, the reversal of the direction of the magnetic field caused by the rotation of the magnet 10, and outputs the generated electric power. The direction of the winding axis of the coil 130 of the power generation element 100 is a direction in which the power generation element 100 extends. The direction of the winding axis of the coil 130 is the direction indicated by the arrow X in the drawings. Hereinafter, the direction of the winding axis of the coil 130 indicated by the arrow X in the drawings may be simply referred to as "the winding axis direction."

[0034] The power generation element 100 includes, for example, the magnetic element assembly 110, the coil 130, the terminals 181, 182 and the housing 190.

[0035] The magnetic element assembly 110 is a composite structure formed by bundling a plurality of magnetic elements, each of which exhibits the strong Barkhausen effect, and a power generation pulse is generated on the coil 130 wound on the magnetic element assembly 110. Details of the magnetic element assembly 110 and the coil 130 will be described later. Note that the position of the power generation element 100 is not particularly limited; it is sufficient that the power generation element 100 is located in an area to which the magnetic field generated by the magnets 10 is applied, and a power generation pulse is generated due to the reversal of the direction of the magnetic field caused by the rotation of the rotary shaft 30.

[0036] Terminals 181, 182 are elements for electrically connecting the power generation element 100 and the substrate 40. Terminals 181, 182 are located at the end portions of the power generation element 100 facing the substrate 40. The magnets 10 are arranged in a direction in which terminals 181, 182 are located as viewed from the power generation element 100. Terminal 181 is electrically connected to one end of a wire of the coil 130, and terminal 182 is electrically connected to the other end of the wire. In other words, the coil 130 and the substrate 40 are electrically connected via terminals 181, 182.

[0037] The housing 190 houses and supports the magnetic element assembly 110 and the coil 130. The magnetic element assembly 110 and the coil 130 are embedded inside the housing 190, for example, in a resin or the like. In addition, the housing 190 houses part of the terminals 181, 182. For example, the power generation element 100 does not include a ferrite head at one end of the magnetic element assembly 110 located in the direction of the winding axis, and the housing 190 does not house the ferrite head. A typical power generation element includes a ferrite head at one end of a magnetic element, such as a Wiegand wire, but the power generation element 100 is capable of ensuring stable power generation even without the ferrite head, as described later; it is possible to reduce the size and cost of the power generation element 100. In the power generating element 100, the housing 190 is open, for example, in the direction of the magnet 10.The housing 190 is attached to the substrate 40, e.g., by a fastener or the like.

[0038] 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 receives electrical signals, such as power generation pulses, generated by the power generation element 100 and detects (calculates) the rotation angle, rotation amount, number of revolutions, etc., of the rotating shaft 30 of a motor or the like based on the received electrical signals. The control circuit 50 is, for example, an integrated circuit (IC) or the like.

[0039] 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, in which the detection result of the control circuit 50 is stored.

[0040] Next, details of the power generation element 100 according to the present exemplary embodiment will be described.

[0041] Fig. 4 is a cross-sectional view illustrating a schematic configuration of the power generation element 100 according to the present exemplary embodiment. Fig. Figure 4 illustrates a cross-section obtained by cutting along a plane perpendicular to the rotation axis line A so that it passes through the winding axis R1 of the coil 130. Note that for the sake of clarity, the illustrations of the terminal 181, the terminal 182 and the housing 190 in Fig. 4 are omitted.

[0042] As in Fig. 4, the power generating element 100 comprises a magnetic element assembly 110 and a coil 130.

[0043] The magnetic element assembly 110 includes a plurality of magnetic elements 120. The plurality of magnetic elements 120 are bundled in the magnetic element assembly 110. The positions of both ends of the plurality of magnetic elements 120, which are located in the direction of the winding axis, are aligned with each other.

[0044] The plurality of magnetic elements 120 are bundled so that the positional relationship between them does not change. The method for bundling the plurality of magnetic elements 120 is not particularly limited; for example, the plurality of magnetic elements 120 are bundled by being fixed to each other by adhesion, bonding, welding, or the like. Alternatively, the plurality of magnetic elements 120 may be bundled by each supporting them on a housing 190, or they may be bundled by a coil 130 or a tape or the like, which are not shown in the drawings.

[0045] The magnetic element 120 is a magnetic element exhibiting the strong Barkhausen effect due to a change in the external magnetic field formed by the magnet 10 or the like. The magnetic element 120 includes a first magnetosensitive part 121 and a second magnetosensitive part 122 having a magnetic property different from the magnetic property of the first magnetosensitive part 121. The second magnetosensitive part 122 has a soft magnetic property with a lower coercive force compared to the first magnetosensitive part 121. The magnetic element 120 is an elongated element whose longitudinal direction is, for example, the direction of the winding axis of the coil 130. The cross-sectional shape of the radially cut magnetic element 120 is, for example, a circle or an ellipse, but may also have other shapes such as a rectangle and a polygon.In the direction of the winding axis, for example, the length of the magnetic element 120 is greater than the length of the coil 130.

[0046] The magnetic element 120 is, for example, a composite magnetic wire having different magnetic properties in a central region and an outer peripheral region defined in the radial direction, such as a Wiegand wire. In the present exemplary embodiment, for example, the central region of the magnetic element 120 defined in the radial direction is a first magnetosensitive part 121 with a relatively high coercive force, and the outer peripheral region of the magnetic element 120 defined in the radial direction is a second magnetosensitive part 122 with a relatively low coercive force. Both the first magnetosensitive part 121 and the second magnetosensitive part 122 extend in the direction of the winding axis. Both the first magnetosensitive part 121 and the second magnetosensitive part 122 are elongated in the direction of the winding axis.Specifically, the first magnetosensitive part 121 is in the shape of a wire extending in the direction of the winding axis, and the second magnetosensitive part 122 is in the shape of a cylinder extending in the direction of the winding axis. The second magnetosensitive part 122 covers a surface of the first magnetosensitive part 121 that is the outer periphery thereof when viewed in the direction of the winding axis, in other words, a surface of the first magnetosensitive part 121 that extends in the direction of the winding axis. The first magnetosensitive part 121 and the second magnetosensitive part 122 are arranged in a direction that crosses the direction of the winding axis (e.g., perpendicular thereto), that is, in the radial direction of the magnetic element 120.Note that the shape of the magnetic element 120 is not limited to the shape just described; it is sufficient for the magnetic element 120 to be a magnetic element including a first magnetosensitive part 121 and a second magnetosensitive part 122 with different magnetic properties to exhibit the strong Barkhausen effect. For example, the magnetic element 120 may include the second magnetosensitive part 122 as the central region and the first magnetosensitive part 121 as the outer peripheral region. Alternatively, the magnetic element 120 may be a magnetic element having a structure in which thin layers with different magnetic properties are stacked.Furthermore, the coercive force between the first magnetosensitive part 121 and the second magnetosensitive part 122 does not need to change abruptly, meaning that the coercive force may change gradually in a region around the boundary between the first magnetosensitive part 121 and the second magnetosensitive part 122. Furthermore, for example, an intermediate layer having a coercive force between the coercive force of the first magnetosensitive part 121 and the coercive force of the second magnetosensitive part 122 may be provided between the first magnetosensitive part 121 and the second magnetosensitive part 122.

[0047] The first magnetosensitive part 121 is magnetized in the direction of the winding axis. For example, a magnetic field of at least 500 Oe is applied to magnetize the first magnetosensitive part 121. A magnetic field of at least 1,000 Oe may be applied, or a magnetic field of at least 3,000 Oe may be applied to magnetize the first magnetosensitive part 121. The direction of magnetization of the first magnetosensitive part 121 does not change due to a 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, a change in the direction of the external magnetic field does not cause a significant change in the direction and state of magnetization of the first magnetosensitive part 121.In addition, the first magnetosensitive part 121 can be in a state of saturated magnetization. Note that Oe is the unit of magnetic field strength, called the oersted, and 1 Oe = (1 / 4π)-103 A / m. Here, π is the ratio of the circumference of a circle to its diameter.

[0048] The plurality of magnetic elements 120 include a first magnetic element 120a and a second magnetic element 120b. The direction of magnetization of the first magnetic element 120a and the direction of magnetization of the second magnetic element 120b are opposite. As shown in Fig. As shown in Figure 4, the first magnetic element 120a is magnetized in the first direction indicated by arrow B1. In contrast, the second magnetic element 120b is magnetized in the second direction indicated by arrow B2, opposite to the first direction.

[0049] The number of first magnetic elements 120a and the number of second magnetic elements 120b in the plurality of magnetic elements 120 are the same. In the Fig. In the example shown in Figure 4, the number of first magnetic elements 120a and the number of second magnetic elements 120b are each one, but the plurality of magnetic elements 120 may include more than one first magnetic element 120a and more than one second magnetic element 120b. As a result, the change in the magnetic flux of the magnetic element assembly 110 increases, enabling an increase in the power generation of the power generation element 100.

[0050] In the Fig. 4, the first magnetic element 120a and the second magnetic element 120b are arranged and bundled in a direction perpendicular to the direction of the winding axis in a plane perpendicular to the arrangement direction.

[0051] The coil 130 is a wire coil that forms the coil 130 and is wound on the magnetic element assembly 110. Specifically, the coil 130 is wound along the winding axis R1, which passes through the center of the magnetic element assembly 110 and extends in the longitudinal direction of the magnetic element assembly 110 (the plurality of magnetic elements 120). [Magnetic properties of a magnetic element composite]

[0052] Next, the strong Barkhausen effect of the magnetic element assembly 110 is described. Fig. 5 is a diagram illustrating an example of a simplified BH curve of the first magnetic element 120a. Fig. 6 is a diagram illustrating an example of a simplified BH curve of the second magnetic element 120b. Similar to Fig. 1, the magnetization directions of the first magnetic element 120a and the second magnetic element 120b are indicated by solid and dashed arrows and dashed in Fig. 5 and Fig. 6. Note that in Fig. 5 and Fig. 6 the arrow indicating a magnetization direction indicates only one magnetization direction, which means that regardless of the magnetization degrees, the magnetization directions are indicated by arrows of the same size. Fig. 7 is a diagram showing the BH curve of the first magnetic element 120a shown in Fig. 5, and the BH curve of the second magnetic element 120b, which is shown in Fig. 6 is applied, are superimposed.

[0053] As in (1) in Fig. 5, in the first magnetic element 120a, even if a magnetic field having a magnetization direction opposite to the magnetization direction of the first magnetosensitive part 121 is applied, the magnetization direction of the first magnetosensitive part 121 is not changed, so that the first magnetosensitive part 121 and the second magnetosensitive part 122 are magnetized in opposite directions. Therefore, when the direction of the magnetic field reverses as in (i) in Fig. 5, the magnetization direction of the second magnetosensitive part 122 changes and becomes the same as the magnetization direction of the first magnetosensitive part 121, as shown in (2) in Fig. 5. In this case, an abrupt reversal of the magnetization direction of the second magnetosensitive part 122, as shown in the figure by the dashed line Ja in Fig. 1 surrounding area is less likely, which means that there is no strong Barkhausen jump.

[0054] On the other hand, if the direction of the magnetic field changes from that in (2) to Fig. 5 shown state changes, as in (ii) in Fig. 5, the direction of magnetization of the second magnetosensitive part 122 does not change due to the effects of the first magnetosensitive part 121 until the magnetic field changes to a certain extent. In the area surrounded by the dashed line Jb, where the change in the magnetic field exceeds a threshold value, the direction of magnetization of the second magnetosensitive part 122 quickly reverses, as shown in (3) and (4) in Fig. 5. As a result, the magnetic flux density of the first magnetic element 120a changes abruptly (in other words, the strong Barkhausen jump occurs), resulting in the generation of electric current (current generation pulse) at the coil 130 wound on the magnetic element assembly 110.

[0055] In a conventional magnetic element, such as in Fig. As shown in Figure 1, a change in the direction of the magnetic field causes a strong Barkhausen jump in two regions surrounded by the dashed line Ja and the dashed line Jb, resulting in the generation of two current generation pulses at the coil. Since the two current generation pulses are due to opposite changes in the magnetic field, the amount of current generation from the two current generation pulses varies when the magnetization state of the magnetic element is unbalanced. For example, if the magnetization intensity of the hard magnetic part in (2) is Fig. 1 and the intensity of the magnetization of the hard magnetic part in (5) in Fig. 1 are different due to the effects of the external magnetic field, a difference in the change of magnetic flux density occurs at the strong Barkhausen jump between the area surrounded by the dashed line Ja and the area surrounded by the dashed line Jb.

[0056] In contrast, in the first magnetic element 120a, the first magnetosensitive part 121 is fully magnetized, and its magnetization direction does not change. This means that a stroke change in the direction of the magnetic field causes the strong Barkhausen jump in a region surrounded by the dashed line Jb, resulting in the generation of a current generation pulse at the coil 130. Therefore, there is no variation between two current generation pulses generated due to a stroke change in the direction of the magnetic field, unlike the situation in the conventional magnetic element. This enables less variation in the electric power generation of the power generation element 100.Furthermore, when the first magnetosensitive part 121 is not fully magnetized, there may be a region of the first magnetosensitive part 121 that is less likely to be magnetized by the external magnetic field formed by the magnet 10 or the like. However, when the first magnetosensitive part 121 is fully magnetized, this region is magnetized, and the magnetic flux density of the first magnetic element 120a changes significantly at the strong Barkhausen jump. Thus, it is possible to generate a stable power generation pulse by the strong Barkhausen jump based on the first magnetic element 120a.

[0057] In the second magnetic element 120b, similar to the first magnetic element 120a, the first magnetosensitive part 121 is fully magnetized and the direction of magnetization does not change, and therefore a stroke change in the direction of the magnetic field causes a strong Barkhausen jump, resulting in the generation of a current generation pulse at the coil 130, as shown in Fig. 6. Therefore, for substantially the same reasons as discussed above with respect to the first magnetic element 120a, it is possible to generate a stable current generation pulse by the strong Barkhausen jump based on the second magnetic element 120b. Note that in the first magnetic element 120a, the strong Barkhausen jump occurs in the area surrounded by the dashed line Jb, but in the second magnetic element 120b, the strong Barkhausen jump occurs in the area surrounded by the dashed line Ja.

[0058] In particular, as in (1) in Fig. 6, when the direction of the magnetic field, as in (i) in Fig. 6, from the state in which a magnetic field is applied to the second magnetic element 120b in the same direction as the direction of magnetization of the first magnetosensitive part 121, the direction of magnetization of the second magnetosensitive part 122 does not change due to the effects of the first magnetosensitive part 121 until the magnetic field changes to a certain extent. In the area surrounded by the dashed line Ja, where the change in the magnetic field exceeds a threshold value, the direction of magnetization of the second magnetosensitive part 122 quickly reverses, as shown in (2) and (3) in Fig. 6. 6. As a result, the magnetic flux density of the second magnetic element 120b changes abruptly (in other words, the strong Barkhausen jump occurs), which leads to the generation of electric current (current generation pulse) at the coil 130 wound on the magnetic composite element 110. Thus, the changes in the direction of the magnetic field in (i) are Fig. 5 and (i) in Fig. 6, but the strong Barkhausen jump does not occur in the first magnetic element 120a, while the strong Barkhausen jump occurs in the second magnetic element 120b.

[0059] As in (4) in Fig. 6, in the second magnetic element 120b, even if a magnetic field having a magnetization direction opposite to the magnetization direction of the first magnetosensitive part 121 is applied, the magnetization direction of the first magnetosensitive part 121 is not changed, and therefore the first magnetosensitive part 121 and the second magnetosensitive part 122 are magnetized in opposite directions. Therefore, when the direction of the magnetic field changes, as in (ii) in Fig. 6, the direction of magnetization of the second magnetosensitive part 122 is reversed and becomes the same as the direction of magnetization of the first magnetosensitive part 121 as shown in (1) in Fig. 6. In this case, an abrupt reversal of the magnetization direction of the second magnetosensitive part 122 is less likely, which means that there is no strong Barkhausen jump. Thus, the changes in the direction of the magnetic field in (ii) are Fig. 5 and (ii) in Fig. 6, but the strong Barkhausen jump occurs in the first magnetic element 120a, while the strong Barkhausen jump does not occur in the second magnetic element 120b. As a result, a stable strong Barkhausen jump based on a single change in the magnetic flux density occurs in both the first magnetic element 120a and the second magnetic element 120b, enabling stable power generation compared to the conventional magnetic element; thus, it is possible to realize the power generation element 100 with less variability in power generation.

[0060] Furthermore, in each of the first magnetic element 120a and the second magnetic element 120b, only one strong Barkhausen jump occurs due to a stroke change in the direction of the magnetic field, but because the direction of magnetization of the first magnetosensitive part 121 and the direction of magnetization of the second magnetosensitive part 122 are opposite in the first magnetic element 120a and the second magnetic element 120b, the strong Barkhausen jump occurs at different times, as shown in Fig. 7. This means that, as in the Fig. 1, two strong Barkhausen jumps occur due to a stroke change in the direction of the magnetic field in the magnetic element assembly 110. [Effects of an external magnetic field]

[0061] The following describes the effects of the external magnetic field when generating electric power with the power generation element 100 according to the present exemplary embodiment. Specifically, the following describes the results of measuring the generated electric current values when the strength of the external magnetic field is changed by changing the distance between the power generation element 100 and the magnet 10.

[0062] Fig. Figure 8 is a schematic diagram illustrating a circuit used to measure the value of electrical energy generated by the power generation element. When measuring the value of electrical energy generated by the power generation element 100, the power generation element 100 and the magnet 10 are arranged so that the Fig. 2 and Fig. 3 is achieved, and the direction of the magnetic field of magnet 10 to be applied to power generating element 100 is repeatedly changed. At this time, a magnetic element 120 having a first magnetosensitive part 121 magnetized by applying a magnetic field of 5,000 Oe is used as the magnetic element 120. In addition, power generating element 100 is connected to a circuit as shown in Fig. 8. Specifically, an output terminal of the power generation element 100 is connected to a full-wave rectification circuit connected to the capacitor C and the resistor R. The post-rectification voltage V of the power generation pulse generated by the power generation element 100 is measured every time the direction of the external magnetic field is reversed, and the voltage V of the power generation pulse multiplied by time is defined as the generated electric power value. The generated electric power value is measured 2,500 times, and the average value and the minimum value of the 2,500 generated electric power measurements are derived.

[0063] Regarding the distance between the magnet 10 and the magnetic element assembly 110, a distance at which the strength of the magnetic field applied to the magnetic element assembly 110 is 20 Oe is set as a reference, and measurement begins. Then, the distance is reduced by 1 mm at a time by moving the magnet 10 and the magnetic element assembly 110 toward each other, and when the distance is reduced by a total of 3 mm or 5 mm, the movement is reversed and the distance is increased by 1 mm at a time so that the distance returns to the original distance. In the following, it is assumed that in Measurement Example 1, the measurement is performed under the condition that the distance is reduced by 3 mm from the reference distance and then the movement is reversed, and that in Measurement Example 2, the measurement is performed under the condition that the distance is reduced by 5 mm from the reference distance and then the movement is reversed.The strength of the magnetic field to be applied to the magnetic element assembly 110 is determined according to the distance between the magnet 10 and the magnetic element assembly 110, and therefore, the strength of the magnetic field to be applied to the magnetic element assembly 110 increases as the distance decreases. Therefore, in Measurement Example 1 and Measurement Example 2, the generated electric power value is measured while performing the operation to gradually increase the strength of the magnetic field to be applied to the magnetic element assembly 110 to a predetermined strength and then return the magnetic field strength to the original strength.

[0064] Fig. 9 is a diagram illustrating the result of measuring the value of electric power generated by the power generation element 100 in Measurement Example 1. Fig. 10 is a diagram illustrating the result of measuring the value of electric energy generated by the power generation element 100 in Measurement Example 2. In Fig. 9 and Fig. 10, the horizontal axis represents a difference between the reference distance and the distance between the magnet 10 and the magnetic element assembly 110. In Fig. 9 and Fig. 10, the vertical axis represents a value of the generated electrical energy measured in the method described above. In the vertical axis, E1 indicates a value of the generated electrical energy with which an electrical signal can be stably detected. In addition, Fig. 9 and Fig. 10 the circle shows the average value of the generated electrical energy, and the triangle shows the minimum value of the generated electrical energy. In addition, Fig. 9 and Fig. 10 the filled circle indicates the mean value of the generated electrical energy. 9 and Fig. 10, the solid line indicates the measurement result obtained by reducing the distance and reversing the movement, and the dashed line indicates the measurement result obtained after reversing the movement. Note that in Fig. 9 and Fig. 10 the unit of the value of the generated electrical energy is an arbitrary unit (au).

[0065] Fig. 9 and Fig. 10 shows that in both Measurement Example 1 and Measurement Example 2, there is only a slight difference between the average value of the generated electrical energy (the drawn circle) and the minimum value of the generated electrical energy (the drawn triangle) before the magnet 10 and the magnetic element assembly 110, which have been moving toward each other, move back (the drawn solid line), which means that the amount of electrical energy generated by the power generation element 100 varies slightly. Furthermore, the value of the generated electrical energy does not fall below E1. This is probably because, as described above, a stroke change in the direction of the magnetic field causes one strong Barkhausen jump in one magnetic element 120, instead of two strong Barkhausen jumps that occur in the prior art, and power generation is stabilized.

[0066] As in Fig. 9, in Measurement Example 1 in which the distance between the magnet 10 and the magnetic composite member 110 is reduced by 3 mm from the reference distance and then the movement is reversed, there is only a slight difference between the average value of the generated electric energy values (the drawn circle) and the minimum value of the generated electric energy (the drawn triangle) even after the magnet 10 and the magnetic element composite 110, which have been moving towards each other, move back (the drawn dashed line), and there is only a slight difference between the value of the generated electric energy before the reversal of the movement and the value of the generated electric energy after the reversal of the movement.When the distance between the magnet 10 and the magnetic element assembly 110 is 3 mm shorter than the reference distance, the strength of the magnetic field applied to the magnetic element assembly 110 is 60 Oe. Therefore, when the strength of the magnetic field applied to the magnetic element assembly 110 is between 20 Oe and 60 Oe, the power generation element 100 is capable of stably generating electric power even when the magnetic field strength fluctuates.

[0067] In contrast, as in Fig. 10, in Measurement Example 2 in which the distance between the magnet 10 and the magnetic element assembly 110 is reduced from the reference distance by 5 mm and then the movement is reversed, there is a larger difference between the average of the generated electric power values (the drawn circle) and the minimum value of the generated electric power (the drawn triangle) when the strength of the magnetic field decreases after the magnet 10 and the magnetic element assembly 110, which have been moving towards each other, move back (the drawn dashed line), which means that the amount of electric power generated by the power generation element 100 varies.Furthermore, the value of electric power generated after the magnet 10 and the magnetic element assembly 110, which have been moving toward each other, move back (the dashed line) is lower than the value of electric power generated before the magnet 10 and the magnetic element assembly 110, which have been moving toward each other, move back (the solid line). This is probably because when a magnetic field with a strength greater than or equal to the predetermined strength is applied to the magnetic element 120 of the magnetic element assembly 110, the magnetization state of the first magnetosensitive part 121 that has been magnetized is changed, and the value of electric power generated by the power generation element 100 and the stability of power generation by the power generation element 100 are lower under the condition where a magnetic field with a lower strength is applied.Nevertheless, this does not mean that the power generation element 100 cannot be used under the condition that a magnetic field with a strength greater than or equal to 60 Oe is applied to the magnetic element assembly 110; for example, the power generation element 100 can stably generate electric power in a certain external magnetic field environment. Furthermore, the magnetization state of the first magnetosensitive part 121 can be made less variable by increasing the strength of the magnetic field applied during magnetization of the first magnetosensitive part 121.

[0068] Furthermore, by manufacturing the power generation element 100 using a magnetic element 120 in which the magnetization state of the first magnetosensitive part 121 is likely to be stable, it is possible to expand the range of the external magnetic field that enables stable operation of the power generation element 100. Examples of the method for stabilizing the magnetization state of the first magnetosensitive part 121 of the magnetic element 120 include: (1) increasing the length of the magnetic element 120; and (2) increasing the coercive force of the magnetic element 120 (first magnetosensitive part 121).

[0069] In method (1), increasing the length of the magnetic element 120 reduces the effects of the diamagnetic field of the magnetic element 120 to which the external field is applied. As a result, the magnetization state of the first magnetosensitive part 121 is stabilized. For example, when the length of the magnetic element 120 is set to 7 mm or more, the magnetization state of the first magnetosensitive part 121 is likely to be stable. When the length of the magnetic element 120 is set to 7 mm or more, the demagnetization factor is likely to be 0.01 or less. Note that the demagnetization factor also changes depending on the thickness of the magnetic element 120, and therefore, the length of the magnetic element 120 can be adjusted so that the demagnetization factor becomes 0.01 or less depending on the thickness of the magnetic element 120.

[0070] In the method (2), increasing the coercive field strength of the magnetic element 120 (first magnetosensitive part 121) results in the magnetization state of the first magnetosensitive part 121 being less variable even if the strength of the external magnetic field increases.

[0071] For example, in manufacturing the power generation element 100, an external magnetic field having the same strength as that of an environment in which the power generation element 100 is to operate is applied to the magnetic element composite 110 manufactured under a predetermined condition. If the magnetization state of the first magnetosensitive part 121 does not change due to the application of the external magnetic field, the power generation element 100 is manufactured using the magnetic element composite 110 without any modifications. On the other hand, if the magnetization state of the first magnetosensitive part 121 changes due to the application of the external magnetic field, the power generation element 100 is manufactured using the magnetic element composite 110 modified by applying the method (1) or (2) described above.To determine a change in the magnetization state of the first magnetosensitive part 121, the value of the electric power generated by the power generation element 100 can be measured as described above, or the BH curve of the magnetic element assembly 110 or the magnetic element 120 can be measured. By such a method, it is possible to manufacture the power generation element 100 capable of generating electric power more stably. [Arrangement of the magnetic elements]

[0072] Next, the arrangement of the plurality of magnetic elements 120 in the magnetic element assembly 110 will be described. Fig. 11 is a diagram for describing the arrangement of the plurality of magnetic elements 120 in the magnetic element assembly 110. In particular, Fig. 11 Examples of the arrangement of the first magnetic element 120a and the second magnetic element 120b when two, four, six and eight magnetic elements 120 are present. Fig. 11 illustrates the arrangement of the first magnetic element 120a and the second magnetic element 120b when the plurality of magnetic elements 120 are viewed in the direction of the winding axis. In Fig. 11, the second magnetic element 120b is marked with halftone dots to distinguish between the first magnetic element 120a and the second magnetic element 120b. The power generation element 100 with the Fig. The arrangement shown closer to the left end in Figure 11 shows better stability of power generation.

[0073] As in Fig. As shown in Figure 11, the plurality of magnetic elements 120 are arranged in a matrix, with, for example, one column facing away from the magnet 10 that forms the external magnetic field, as viewed in the direction of the winding axis. Note that one of the rows and columns of the plurality of magnetic elements 120 may be a single row. In other words, the plurality of magnetic elements 120 may be arranged in a row.

[0074] In addition, as in Fig. 11, the plurality of magnetic elements 120 arranged such that the first magnetic element 120a and the second magnetic element 120b are alternately arranged (for example, the first and second arrangements are on the left when the number of magnetic elements 120 is four or more) allows the power generation element 100 to have better power generation stability. This is because the magnetic poles of the first magneto-sensitive parts 121 magnetized in opposite directions in the first magnetic element 120a and the second magnetic element 120b are prevented from repelling each other, thereby stabilizing the magnetization state of the first magneto-sensitive parts 121. In this case, for example, one of each pair of adjacent magnetic elements 120 among the plurality of magnetic elements 120 is a first magnetic element 120a and the other is a second magnetic element 120b.For example, in the plurality of magnetic elements 120, the first magnetic elements 120a are not adjacent to each other and the second magnetic elements 120b are not adjacent to each other in both the row direction and the column direction.

[0075] In addition, as in Fig. As shown in FIG. 11, when there are two or more first magnetic elements 120a and two or more second magnetic elements 120b (when there are four or more magnetic elements 120), the power generation stability of the power generation element 100 is better when the number of first magnetic elements 120a and the number of second magnetic elements 120b is each an even number than when the number of first magnetic elements 120a and the number of second magnetic elements 120b is each an odd number. This is because the plurality of magnetic elements 120 can be easily arranged so that the symmetry of the magnetization state of the entire magnetic element assembly 110 is likely to be maintained.

[0076] As in Fig. As shown in Figure 11, the power generation element 100 has better power generation stability when the number of magnetic elements 120 arranged in the column direction (the direction away from the magnet 10) is less than or equal to the number of magnetic elements 120 arranged in the row direction. This is because the number of magnetic elements 120 arranged in the direction away from the magnet 10 is small (the number of magnetic elements 120 arranged in the direction away from the magnet 10 does not exceed the number of magnetic elements 120 arranged in the row direction), and the strength of the applied magnetic field is less likely to vary among the plurality of magnetic elements 120. The number of magnetic elements 120 arranged in the column direction may be less than the number of magnetic elements 120 arranged in the row direction. [Conclusions]

[0077] As described above, a power generation element according to the first aspect of the present disclosure includes: a magnetic element assembly 110 including a plurality of magnetic elements 120 bundled together, each of which exhibits a strong Barkhausen effect due to a change in an external magnetic field; and a coil 130 wound on the magnetic element assembly 110. Each of the plurality of magnetic elements 120 includes a first magnetosensitive part 121 and a second magnetosensitive part 122 that is magnetically softer than the first magnetosensitive part 121. The first magnetosensitive part 121 is magnetized in the direction of the winding axis of the coil 130, and the magnetization direction of the first magnetosensitive part 121 does not change due to a change in the direction of the external magnetic field.The plurality of magnetic elements 120 include a first magnetic element 120a in which the first magnetosensitive part 121 is magnetized in a first direction, and a second magnetic element 120b in which the first magnetosensitive part 121 is magnetized in a second direction opposite to the first direction.

[0078] As just described, the first magnetosensitive part 121 of the magnetic element 120 included in the magnetic element assembly 110 is magnetized, and thus the magnetization direction of the first magnetosensitive part 121 is fixed regardless of the direction of the external magnetic field. As a result, the strong Barkhausen jump caused by an abrupt change in the magnetization direction of the second magnetosensitive part 122 in a direction opposite to the magnetization direction of the first magnetosensitive part 121 occurs once due to a single stroke change in the direction of the external magnetic field.This eliminates fluctuations in the value of the power generation pulse that occur in the conventional magnetic element due to a difference between the magnification states of the first magnetosensitive part 121 during two strong Barkhausen jumps caused by a stroke change in the direction of the external magnetic field. As a result, the value of the power generation pulse generated at the coil 130 by the strong Barkhausen jump is stabilized. Thus, it is possible to realize a power generation element that can reduce fluctuations in the amount of power generation.In addition, since the plurality of magnetic elements 120 of the magnetic element assembly 110 includes a first magnetic element 120a and a second magnetic element 120b in which the magnetization directions of the first magnetosensitive part 121 are opposite to each other, two large Barkhausen jumps are possible in the magnetic element assembly 110 due to a stroke change in the direction of the external magnetic field, and the number of current generation pulses of the current generation element can be maintained at the same level as when using the conventional magnetic element.

[0079] A power generation element according to the second aspect of the present disclosure is the power generation element according to the first aspect, in which the plurality of magnetic elements 120 includes a plurality of the first magnetic elements 120a and a plurality of the second magnetic elements 120b.

[0080] This allows for a significant change in the magnetic flux density in the strong Barkhausen jump. Therefore, the power generation element can generate more stable power by increasing the amount of power generation.

[0081] A power generation element according to the third aspect of the present disclosure is the power generation element according to the second aspect, in which the plurality of magnetic elements 120 are arranged such that first magnetic elements 120a and second magnetic elements 120b are arranged alternately.

[0082] Thus, the magnetic poles of the first magnetosensitive parts 121, which are magnetized in opposite directions in the first magnetic element 120a and the second magnetic element 120b, are prevented from repelling each other, thereby stabilizing the magnetization state of the first magnetosensitive parts 121. Therefore, the power generation element can generate electric power more stably.

[0083] A power generation element according to the fourth aspect of the present disclosure is the power generation element according to the second or third aspect, in which the total number of the first magnetic elements 120a and the total number of the second magnetic elements 120b is each an even number.

[0084] In this way, the plurality of magnetic elements 120 can be easily arranged so that the symmetry of the magnetization state of the entire magnetic element assembly 110 is likely to be maintained. Therefore, the power generation element can generate electric power more stably.

[0085] A power generation element according to the fifth aspect of the present disclosure is the power generation element according to any one of the second to fourth aspects, in which the plurality of magnetic elements 120 are arranged in a matrix with a column directed away from the magnet 10 forming the external magnetic field as viewed in the winding axis direction, and a total number of magnetic elements 120 arranged in a column direction among the plurality of magnetic elements 120 is less than or equal to a total number of magnetic elements 120 arranged in a row direction among the plurality of magnetic elements 120.

[0086] Thus, the number of magnetic elements 120 arranged in the direction away from the magnet 10 is small (the number of magnetic elements 120 arranged in the direction away from the magnet 10 does not exceed the number of magnetic elements 120 arranged in the row direction), and the strength of the applied magnetic field is less likely to differ among the plurality of magnetic elements 120. Therefore, the power generation element can generate electric power more stably.

[0087] A power generation element according to the sixth aspect of the present disclosure is the power generation element according to any one of the first to fifth aspects, in which a ferrite head arranged at one end of the magnetic element assembly 110 located in the direction of the winding axis is not included.

[0088] In this way, the size and cost of the power generation element can be reduced.

[0089] A power generation system according to the seventh aspect of the present disclosure includes: the 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 direction of the magnetic field applied to the power generation element. The power generation element generates electric power by reversing the direction of the magnetic field caused by the magnet 10.

[0090] Since the power generation element described above is included, it is possible to realize a power generation system that can reduce fluctuations in the amount of power generation.

[0091] A power generation system according to the eighth aspect of the present disclosure is the power generation system according to the seventh aspect, in which the strength of the magnetic field applied to the magnetic element assembly 110 of the power generation element described above is between 20 Oe and 60 Oe inclusive.

[0092] In this way, the magnification state of the first magnetosensitive part 121 is less sensitive to the applied magnetic field, which means that the power generation element can generate electric current more stably.

[0093] Furthermore, an 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 the electric current generated by reversing the direction of the magnetic field by the magnet 10.

[0094] Thus, the electrical energy of the power generation element described above is output, which can reduce fluctuations in the amount of power generation, which means that the detection accuracy of the encoder can be improved. (Other exemplary embodiments)

[0095] The power generation element, the power generation system, and the encoder according to the present disclosure have been described so far based on the exemplary embodiment, but the present disclosure is not limited to the above-described exemplary embodiment. Forms obtained by various modifications of the above-described exemplary embodiment that can be conceived by those skilled in the art, and forms established by arbitrarily combining structural elements and functions in the exemplary embodiment without departing from the spirit of the present disclosure are included in the present disclosure.

[0096] In the exemplary embodiment described above, the power generation element 100 does not include a ferrite head, but this is not limiting. To improve the ability to collect the magnetic force from the magnet 10, the power generation element 100 may include a ferrite head at one end of the magnetic element assembly 110.

[0097] Furthermore, in the exemplary embodiment described above, the power generation element 100 includes a magnetic element assembly 110 formed by bundling the plurality of magnetic elements 120, but this is not limitative. In applications where the number of power generation times may be reduced due to a stroke change in the direction of the magnetic field, the power generation element 100 may include a magnetic element 120 instead of the magnetic element assembly 110. For example, the number of magnetic poles of the magnet 10, which rotates together with the rotating shaft 30, may be increased to increase the number of power generation times of the power generation element 100.

[0098] Furthermore, in the exemplary embodiment described above, the position of the power generation element 100 is fixed, and the direction of the magnetic field applied to the power generation element 100 is repeatedly reversed as a result of the rotation of the magnet 10 by the rotation of the rotary shaft 30, but this is not limitative. The position of the magnet 10 may be fixed, and the direction of the magnetic field applied to the power generation element 100 may be repeatedly reversed as a result of the rotation of the power generation element 100 by the rotation of the rotary shaft 30.

[0099] Furthermore, in the exemplary embodiment described above, a rotary encoder used in combination with a motor is described as an example, but not by way of limitation. The techniques of the present disclosure can also be applied to a linear encoder. Industrial applicability

[0100] The power generation element, the power generation system and the encoder according to the present disclosure are useful for an apparatus, device or the like that rotates or moves linearly, such as a motor. Reference character list 1 encoder 5 Power generation system 10 Magnet 20 turntable 30 rotating shaft 40 Substrat 50 tax circuit 60 storage 100 power generation elements 110 magnetic element composite 120 magnetic element 120a first magnetic element 120b second magnetic element 121 first magnetosensitive part 122 second magnetosensitive part 130 coil 181, 182 connection 190 housings QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2012-198067

[0003]

Claims

[1] A power generating element comprising: a magnetic element assembly comprising a plurality of bundled magnetic elements, each of the plurality of magnetic elements having a strong Barkhausen effect due to a change in an external magnetic field; and a coil wound on the magnetic element assembly, wherein each of the plurality of magnetic elements includes a first magnetosensitive part and a second magnetosensitive part which is magnetically softer than the first magnetosensitive part, the first magnetosensitive part is magnetized in a winding axis direction of the coil and a magnetization direction of the first magnetosensitive part does not change due to a change in a direction of the external magnetic field, and the plurality of magnetic elements comprise a first magnetic element in which the first magnetosensitive part is magnetized in a first direction, and a second magnetic element in which the first magnetosensitive part 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 elements comprise a plurality of the first magnetic elements and a plurality of the second magnetic elements. [3] The power generation element according to claim 2, wherein the plurality of magnetic elements are arranged such that the first magnetic elements and the second magnetic elements are arranged alternately. [4] The power generation element according to claim 2, wherein each of the total number of the first magnetic elements and the total number of the second magnetic elements is an even number. [5] The power generation element according to claim 2, wherein the plurality of magnetic elements are arranged in a matrix with a column directed away from a magnetic field source forming the external magnetic field, viewed in the direction of the winding axis, and a total number of magnetic elements among the plurality of magnetic elements arranged in a column direction is less than or equal to a total number of magnetic elements among the plurality of magnetic elements arranged in a row direction. [6] The power generating element according to claim 1, wherein a ferrite head arranged at an end of the magnetic element assembly located in the direction of the winding axis is not included. [7] A system for generating electricity comprising: the power generating element according to any one of claims 1 to 6; and a magnetic field applying part which applies a magnetic field to the power generating element and repeatedly reverses the direction of the magnetic field applied to the power generating element, wherein the power generating element generates electric current by reversing the direction of the magnetic field caused by the magnetic field applying part. [8] The power generation system according to claim 7, wherein the strength of the magnetic field applied to the magnetic element assembly of the power generation element is between 20 Oe and 60 Oe. [9] An encoder comprising: the power generation system according to claim 7, wherein the power generating element outputs the electrical energy generated by the reversal of the direction of the magnetic field caused by the magnetic field applying part.

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