Manufacturing method for power generation element, encoder, and magnetic member

Abstract

Provided are a power-generating element, an encoder, and a method for producing a magnetic member that make it possible to increase the amount of electric power generated. This power-generating element (100) comprises a magnetic member (110) that produces a large Barkhausen effect, a coil (130) wound on the magnetic member (110), and a ferrite member (150) that is provided to an end section of the magnetic member (110) so as to be lined up with the coil (130) along the winding-axis direction of the coil (130). The ferrite member (150) has a body section (151) that is positioned inside a columnar space (A), and a protrusion section (152) that is positioned outside of the columnar space (A) and that is linked to the body section (151). The columnar space (A) is surrounded by a virtual plane for which it is assumed that the outer edge of the coil (130) is extended toward both sides in the winding-axis direction of the coil (130) as seen from the winding-axis direction of the coil (130), and moreover is sandwiched by two virtual planes that are orthogonal to the winding-axis direction of the coil (130) and that respectively touch the two coil-winding-axis-direction ends of the magnetic member (110).

Description

Technical Field

[0001] The present disclosure relates to a power generation element, an encoder, and a method for manufacturing a magnetic member, and particularly relates to a power generation element, an encoder, and a method for manufacturing a magnetic member that utilize the large Barkhausen effect.

Background Art

[0002] Conventionally, among encoders for detecting the rotation of a motor or the like, an encoder using a power generation element that utilizes the large Barkhausen effect to detect rotation without using a battery is known (for example, Patent Document 1). Such a power generation element has a configuration in which a coil is wound around a magnetic member that produces the large Barkhausen effect, for example. Since the magnetic flux density of the magnetic member producing the large Barkhausen effect changes abruptly in response to a change in an external magnetic field, electric power is generated in the coil wound around the magnetic member due to the abrupt change in magnetic flux density. The encoder detects the rotation of the motor or the like using an electric signal generated by such electric power.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] In the above-described encoder, the operation may become unstable because the electric power generated by the power generation element is small.

[0005] The present disclosure has been made to solve such a problem, and an object thereof is to provide a power generation element, an encoder, and a method for manufacturing a magnetic member that can increase generated electric power.

[0006] To achieve the above objective, a power generation element according to one aspect of the present disclosure comprises a magnetic member that generates a large Barkhausen effect by a change in an external magnetic field formed by a magnetic field source, a coil wound around the magnetic member, and a ferrite member provided at the end of the magnetic member alongside the coil. The ferrite member has a main body and a protruding portion that protrudes from the main body. The main body is surrounded by a virtual plane formed by assuming that the outer edge of the coil, when viewed from the winding axis direction of the coil, is extended to both sides in the winding axis direction of the coil, and is located inside a columnar space sandwiched between two virtual planes that are in contact with both ends of the magnetic member in the winding axis direction of the coil and are perpendicular to the winding axis direction of the coil. The protruding portion is connected to the main body and is located outside the columnar space.

[0007] Furthermore, a power generation element according to another aspect of the present disclosure comprises a magnetic member that generates a Great Barkhausen effect by a change in an external magnetic field formed by a magnetic field source, a cylindrical ferrite member enclosing the magnetic member, and a coil wound around the ferrite member.

[0008] Furthermore, a power generation element according to another aspect of the present disclosure comprises a magnetic member that generates a large Barkhausen effect by a change in an external magnetic field formed by a magnetic field source, a coil wound around the magnetic member, and a ferrite member provided at the end of the magnetic member so as to be aligned with the coil along the winding axis of the coil. The ferrite member is a resin molded body containing at least one of soft magnetic powder and hard magnetic powder and a resin.

[0009] Furthermore, a power generation element according to another aspect of the present disclosure comprises a magnetic member that generates a large Barkhausen effect due to a change in an external magnetic field formed by a magnetic field source, and a coil wound around the magnetic member. In the winding axis direction of the coil, the outer diameter of the ends of the coil is smaller than the outer diameter of the central part of the coil.

[0010] Furthermore, a power generation element according to another aspect of the present disclosure comprises a magnetic member that generates a Great Barkhausen effect by a change in an external magnetic field formed by a magnetic field source, a first coil wound around the magnetic member, and a second coil arranged opposite to the first coil on the side of the first coil away from the magnetic field source, and wound along an axis parallel to the winding axis of the first coil.

[0011] Furthermore, a power generation element according to another aspect of the present disclosure comprises a plate-shaped magnetic member that generates a large Barkhausen effect by a change in an external magnetic field formed by a magnetic field source, and a coil wound around the magnetic member. The magnetic member has a plurality of first magnetic-sensitive layers and a plurality of second magnetic-sensitive layers that are harder magnetic than the plurality of first magnetic-sensitive layers, and the plurality of first magnetic-sensitive layers and the plurality of second magnetic-sensitive layers are stacked alternately along a direction intersecting the winding axis of the coil, and the total thickness of the plurality of first magnetic-sensitive layers is greater than the total thickness of the plurality of second magnetic-sensitive layers.

[0012] Furthermore, a power generation element according to another aspect of the present disclosure comprises a magnetic member that generates a Great Barkhausen effect by a change in an external magnetic field formed by a magnetic field source, and a coil wound around the magnetic member. The magnetic member comprises a composite magnetic wire having different magnetic properties in its central portion and outer peripheral portion, and a coating layer made of a soft magnetic material that covers the outer circumference of the composite magnetic wire.

[0013] Furthermore, an encoder according to another aspect of the present disclosure comprises a magnet that rotates together with a rotation axis, and a power generation element according to any of the above aspects that generates an electrical signal by a change in the magnetic field formed by the magnet as the magnet rotates.

[0014] Furthermore, another embodiment of the present disclosure relates to a method for manufacturing a magnetic member used in a power generation element and which produces the Great Barkhausen effect, and includes the steps of: preparing a cylindrical magnetic body; and injecting a magnetic material having different magnetic properties from the magnetic body into the interior of the magnetic body.

[0015] Furthermore, another embodiment of the present disclosure relates to a method for manufacturing a magnetic member used in a power generation element and which produces the Great Barkhausen effect, and includes the steps of: preparing a wire-shaped magnetic material; and coating the surface of the magnetic material with a magnetic material having different magnetic properties from the magnetic material.

[0016] According to this disclosure, the power generated by the power generation element can be increased. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a cross-sectional view showing a schematic configuration of an encoder according to Embodiment 1. [Figure 2] Figure 2 is a top view of the magnet in the encoder according to Embodiment 1. [Figure 3] Figure 3 is a cross-sectional view showing the schematic configuration of the power generation element according to Embodiment 1. [Figure 4] Figure 4 shows an example of a schematic BH curve for a magnetic material that exhibits the large Barkhausen effect. [Figure 5] Figure 5 is a cross-sectional view showing the schematic configuration of a power generation element according to a modified example 1 of Embodiment 1. [Figure 6] Figure 6 is a cross-sectional view showing the schematic configuration of a power generation element according to a modified example 2 of Embodiment 1. [Figure 7] Figure 7 is a cross-sectional view showing the schematic configuration of a power generation element according to a modified example 3 of Embodiment 1. [Figure 8] Figure 8 is a cross-sectional view showing the schematic configuration of a power generation element according to a modified example 4 of Embodiment 1. [Figure 9] Figure 9 is a cross-sectional view showing the schematic configuration of a power generation element according to a modified example 5 of Embodiment 1. [Figure 10] Figure 10 is a cross-sectional view showing the schematic configuration of a power generation element according to a modified example 6 of Embodiment 1. [Figure 11] Figure 11 is a cross-sectional view showing the schematic configuration of a power generation element according to a modified example 7 of Embodiment 1. [Figure 12] Figure 12 is a cross-sectional view showing the schematic configuration of the power generation element according to Embodiment 2. [Figure 13] FIG. 13 is a cross-sectional view showing a schematic configuration of a power generating element according to Modification 1 of Embodiment 2. [Figure 14] FIG. 14 is a cross-sectional view showing a schematic configuration of a power generating element according to Embodiment 3. [Figure 15] FIG. 15 is a cross-sectional view showing a schematic configuration of a power generating element according to Embodiment 4. [Figure 16] FIG. 16 is a cross-sectional view showing a schematic configuration of a power generating element according to Embodiment 5. [Figure 17] FIG. 17 is a diagram showing a cross-sectional view and a top view illustrating a schematic configuration of a magnetic member according to Embodiment 6. [Figure 18] FIG. 18 is a diagram showing a cross-sectional view and a top view illustrating a schematic configuration of a magnetic member according to Modification 1 of Embodiment 6. [Figure 19] FIG. 19 is a diagram showing a cross-sectional view and a top view illustrating a schematic configuration of a magnetic member according to Modification 2 of Embodiment 6. [Figure 20] FIG. 20 is a cross-sectional view showing a schematic configuration of a power generating element according to Embodiment 7. [Figure 21] FIG. 21 is a flowchart of Example 1 of the method for manufacturing a magnetic member according to Embodiment 7. [Figure 22] FIG. 22 is a flowchart of Example 2 of the method for manufacturing a magnetic member according to Embodiment 7. [Mode for Carrying Out the Invention]

[0018] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Accordingly, the numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, and the like shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims of the present disclosure will be described as optional constituent elements.

[0019] Please note that each figure is a schematic diagram and not necessarily a strictly accurate representation. Therefore, the scale and other aspects may not necessarily be consistent across all figures. In addition, the same reference numerals are used for substantially identical components in each figure, and redundant explanations are omitted or simplified.

[0020] Furthermore, in this specification, terms indicating relationships between elements such as parallelism, terms indicating the shape of elements such as rectangles, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0021] (Embodiment 1) The encoder 1 and power generation element 100 according to Embodiment 1 will be described below.

[0022] Figure 1 is a cross-sectional view showing the schematic configuration of the encoder 1 according to this embodiment. Figure 2 is a top view of the magnet 10 in the encoder 1 according to this embodiment. In Figure 1, the magnetic member 110 and coil 130 housed in the housing 190 of the power generation element 100 are schematically shown with dashed lines. Also, for clarity, in Figure 2, other than the magnet 10, the rotating shaft 30, and the magnetic member 110 and coil 130 in the power generation element 100 are omitted from the illustration.

[0023] The encoder 1 shown in Figure 1 is a rotary encoder used in combination with a motor, such as a servo motor. The encoder 1 is also an absolute encoder of the power generation type. The encoder 1 detects, for example, the rotation angle, amount of rotation, and rotation speed of a rotating shaft 30 of a motor, based on an electrical signal generated by the power generation element 100. The encoder 1 comprises a magnet 10, a rotating plate 20, a substrate 40, a control circuit 50, a memory 60, and the power generation element 100. In the encoder 1, the power generation element 100 generates an electrical signal based on the change in the magnetic field formed by the magnet 10 as the magnet 10 rotates.

[0024] The rotating plate 20 is a plate-shaped member that rotates together with the rotating shaft 30 of a motor or the like. The center of one main surface of the rotating plate 20 is attached to the end of the rotating shaft 30 in the axial direction (the direction in which the rotating shaft 30 extends). The rotating plate 20 extends in a direction perpendicular to the axial direction of the rotating shaft 30. The rotating plate 20 rotates around the rotating shaft 30 as its center of rotation. The rotational movement of the rotating shaft 30 is synchronized with the rotational movement of the rotating equipment. The planar shape of the rotating plate 20 is, for example, circular. The rotating plate 20 is made of, for example, metal, resin, glass, or ceramic.

[0025] The magnet 10 is a magnetic field source that forms an external magnetic field for 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 rotation axis 30. The thickness direction of the rotating plate 20 and the thickness direction of the magnet 10 are the same and are in the axial direction of the rotation axis 30. The magnet 10 rotates together with the rotating plate 20 about the rotation axis 30 as the center of rotation. The rotation direction of the magnet 10 can be, for example, both clockwise and counterclockwise, but it may also be either clockwise or counterclockwise or only one of them. The plan view shape of the magnet 10 is a circular shape with an opening in the center, but it may be another shape such as a rectangle. Also, the magnet 10 does not have to be open. Furthermore, the magnet 10 may be a magnet of other shapes, such as a rod-shaped magnet, as long as it can change the magnetic field applied to the power generation element 100.

[0026] The magnet 10 has multiple pairs of magnetic poles that are magnetized in the thickness direction, and these multiple pairs of magnetic poles are aligned in the rotation direction of the magnet 10. In Figure 2, the magnetic poles on the main surface 11 side of the magnet 10, which is the side facing the power generation element 100, are shown. Each pair of magnetic poles is magnetized such that the north and south poles are reversed relative to adjacent pairs of magnetic poles in the rotation direction of the magnet 10.

[0027] In the magnet 10, multiple magnetic poles are aligned in the rotational direction on the main surface 11 of the magnet 10 on the power generation element 100 side. Each of the multiple magnetic poles includes at least one north pole and at least one south pole, with the north and south poles alternating along the rotational direction. In the multiple magnetic poles of the magnet 10, the number of north poles and the number of south poles are the same.

[0028] The multiple magnetic poles are arranged so that the north pole and south pole face each other across the rotation axis 30. That is, the north pole of the multiple magnetic poles faces the south pole across the rotation axis 30, and the south pole of the multiple magnetic poles faces the north pole across the rotation axis 30. In the multiple magnetic poles, the south pole is located 180 degrees offset from the north pole in the direction of rotation of the magnet 10, and the north pole is located 180 degrees offset from the south pole. When viewed from the axial direction of the rotation axis 30, the magnitude of each magnetic pole of the multiple magnetic poles is equal. As such a magnet 10 rotates, the magnetic field applied to the power generation element 100 changes. In the example shown in Figure 2, there are two multiple magnetic poles, including one north pole and one south pole. Therefore, when the magnet 10 rotates once with the rotation axis 30, the direction of the magnetic field applied to the power generation element 100 reverses twice (one cycle). The number of multiple magnetic poles is not particularly limited and may be four, or six or more. When the magnet 10 rotates once, the direction of the magnetic field applied to the power generation element 100 reverses a number of times equal to the number of magnetic poles.

[0029] The substrate 40 is positioned on the magnet 10 side of the rotating plate 20, facing the rotating plate 20 and the magnet 10 with a gap between them. In other words, the rotating shaft 30, rotating plate 20, magnet 10, and substrate 40 are arranged in this order along the axial direction of the rotating shaft 30. The substrate 40 does not rotate with the magnet 10 and the rotating plate 20. The substrate 40 is plate-shaped with the axial direction of the rotating shaft 30 as its thickness direction. The planar shape of the substrate 40 is, for example, circular. For example, when viewed from the axial direction of the rotating shaft 30, the centers of the rotating shaft 30, rotating plate 20, magnet 10, and substrate 40 coincide.

[0030] The substrate 40 is, for example, a wiring board on which electronic components such as the power generation element 100, control circuit 50, and memory 60 are mounted. In the example shown in Figure 1, the control circuit 50 and memory 60 are mounted on the main surface of the substrate 40 on the side 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 magnet 10. The substrate 40 is fixed to, for example, a case (not shown) that constitutes part of an encoder 1 or a motor.

[0031] The power generation element 100 is located on the main surface of the substrate 40 opposite to the magnet 10 side. Therefore, the substrate 40 side of the power generation element 100 is the magnet 10 side. The power generation element 100 is aligned with the magnet 10 and the rotating plate 20 along the axial direction of the rotation axis 30. Hereafter, the direction indicated by arrow Z, in which the magnet 10, the rotating plate 20 and the power generation element 100 are aligned, may be referred to as the "alignment direction." The alignment direction is also the normal direction to the main surface 11 of the magnet 10. The power generation element 100 does not rotate together with the magnet 10 and the rotating plate 20. At least a portion of the power generation element 100 is provided so as to face the magnet 10 and the rotating plate 20 in the axial direction of the rotation axis 30. Furthermore, the power generation element 100 extends along the main surface of the substrate 40 in a direction that intersects (specifically, is perpendicular to) the radial direction of the magnet 10. The power generation element 100 generates electricity and produces an electrical signal due to the change in the magnetic field formed by the magnet 10 as the magnet 10 rotates. The winding axis direction of the coil 130 of the power generation element 100 (the longitudinal direction of the magnetic member 110) is the direction in which the power generation element 100 extends. The winding axis direction of the coil 130 is indicated by the arrow X in the figure. Hereafter, 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".

[0032] The power generation element 100 includes, for example, a magnetic member 110, a coil 130, a ferrite member 150 (not shown in Figures 1 and 2) as shown in the cross-sectional view of Figure 3, terminals 181 and 182, and a housing 190.

[0033] Details of the magnetic member 110, the coil 130, and the ferrite member 150 will be described later. The magnetic member 110 is a magnetic member that produces the Great Barkhausen effect, and power generation pulses are generated in the coil 130 wound around the magnetic member 110. The arrangement of the power generation element 100 is not particularly limited, and the power generation element 100 should be located in the region to which the magnetic field generated by the magnet 10 is applied, and should be arranged so as to generate power generation pulses due to the change in the magnetic field caused by the rotation of the rotation shaft 30.

[0034] Terminals 181 and 182 are components for electrically connecting the power generation element 100 and the substrate 40. Terminals 181 and 182 are located at the end of the power generation element 100 that faces the substrate 40. The magnet 10 is positioned on the terminal 181 and 182 side of the power generation element 100. Terminal 181 is electrically connected to one end of the conductor constituting the coil 130, and terminal 182 is electrically connected to the other end of the conductor. In other words, the coil 130 and the substrate 40 are electrically connected via terminals 181 and 182.

[0035] The housing 190 houses and supports the magnetic member 110, the coil 130, and the ferrite member 150. The housing 190 also houses parts of the terminals 181 and 182. The housing 190 opens, for example, to the magnet 10 side of the power generation element 100. The housing 190 is fixed to the substrate 40 by, for example, fixing members not shown in the figure.

[0036] The control circuit 50 is located on the main surface of the substrate 40 on the magnet 10 side. 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 based on the acquired electrical signals, detects (calculates) the rotation angle, amount of rotation, and rotation speed of the rotating shaft 30 of the motor or the like. The control circuit 50 is, for example, an IC (integrated circuit) package.

[0037] The memory 60 is located on the main surface of the substrate 40 on the magnet 10 side. The memory 60 is connected to the control circuit 50. The memory 60 is a non-volatile memory such as a semiconductor memory that stores the results detected by the control circuit 50.

[0038] Next, the details of the power generation element 100 according to this embodiment will be described.

[0039] Figure 3 is a cross-sectional view showing the schematic configuration of the power generation element 100 according to this embodiment. Figure 3 shows a cross-section when cut along the direction of alignment, passing through the winding axis R1 of the coil 130. For ease of viewing, terminals 181, 182 and the housing 190 are omitted from Figure 3. The same applies to the diagrams of each power generation element described below.

[0040] As shown in Figure 3, the power generation element 100 comprises a magnetic member 110, a coil 130, and a ferrite member 150.

[0041] The magnetic member 110 is a magnetic member that generates the Great Barkhausen effect due to changes in the external magnetic field formed by the magnet 10 or the like. The magnetic member 110 is, for example, a composite magnetic wire having different magnetic properties in the radial central portion and the outer peripheral portion, such as a Wiegand wire. In the composite magnetic wire, one of the central portion and the outer peripheral portion is a hard magnetic portion, and the other is a soft magnetic portion. In this embodiment, for example, in the composite magnetic wire, the central portion is a hard magnetic portion with high coercivity, and the outer peripheral portion is a soft magnetic portion with lower coercivity than the central portion. The soft magnetic portion covers the hard magnetic portion from the radial outside.

[0042] Here, we will explain the large Barkhausen effect. Figure 4 shows an example of a schematic BH curve for a magnetic member 110 that exhibits the large Barkhausen effect. In Figure 4, an example is shown in which a composite magnetic wire, in which the outer portion is softer magnetic than the central portion, is used as the magnetic member 110. Figure 4 also shows the case where the direction of the applied magnetic field changes along the longitudinal direction of the wire. Furthermore, (1) to (6) of Figure 4 schematically show the magnetic member 110 with the direction of magnetization indicated by arrows. The dashed arrows indicate the direction of magnetization of the soft magnetic outer portion, and the solid arrows indicate the direction of magnetization of the hard magnetic central portion. Note that in Figure 4, the arrows indicating the direction of magnetization only show the direction of magnetization, and the direction of magnetization is indicated by arrows of the same size regardless of the magnitude of magnetization.

[0043] When a magnetic field of a certain strength or greater is applied to the magnetic member 110 along its longitudinal direction, the central and outer portions of the magnetic member 110 are magnetized in the same direction, as shown in Figure 4(1). Even if the direction of the magnetic field changes, as shown in Figure 4(i), the magnetization direction of the soft magnetic outer portion does not change up to a certain point due to the influence of the hard magnetic central portion. At the point enclosed by the dashed line Ja where the change in the magnetic field exceeds the threshold, the magnetization direction of the soft magnetic outer portion suddenly reverses, as shown in Figures 4(2) and (3). This phenomenon is also called the large Barkhausen jump. As a result, the magnetic flux density of the magnetic member 110 changes rapidly, and power (generating pulses) is generated in the coil 130 wound around the magnetic member. If the magnetic field is changed further, the magnetization direction of the central portion also reverses, as shown in Figure 4(4), and the magnetic member 110 is magnetized in the opposite direction to that shown in Figure 4(1). In this case as well, by changing the direction of the magnetic field as shown in Figure 4(ii), the magnetization direction of the outer periphery is abruptly reversed at the point enclosed by the dashed line Jb where the change in the magnetic field exceeds the threshold, as shown in Figures 4(5) and (6). This causes a rapid change in the magnetic flux density of the magnetic member 110, and power (generating pulses) is generated again in the coil 130 wound around the magnetic member 110. This behavior also occurs in composite magnetic wires where the outer periphery is hard magnetic and the central part is soft magnetic.

[0044] Thus, the magnetic member 110 is a magnetic member that exhibits the behavior shown in Figure 4. Note that the magnetic member 110 is not limited to a composite magnetic wire; any magnetic member that produces the Great Barkhausen effect by having a hard magnetic portion and a soft magnetic portion with different magnetic properties is acceptable. In the magnetic member 110, for example, the Great Barkhausen effect occurs when the hard magnetic portion and the soft magnetic portion are aligned in a direction that intersects (e.g., perpendicular to) the winding axis direction, and the hard magnetic portion and the soft magnetic portion extend in the winding axis direction. The magnetic member 110 may also be a magnetic member having a structure in which thin films with different magnetic properties are laminated.

[0045] Referring again to Figure 3, the magnetic member 110 is, for example, a long member whose longitudinal direction is the winding axis direction of the coil 130. The cross-sectional shape of the magnetic member 110 when cut radially 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 110 is, for example, longer than the length of the coil 130.

[0046] The coil 130 is a coil in which the conductors constituting the coil 130 are wound around the magnetic member 110. Specifically, the coil 130 is wound along a winding axis R1 that passes through the center of the magnetic member 110 and extends in the longitudinal direction of the magnetic member 110. The coil 130 is also located between the two ferrite members 150.

[0047] The ferrite member 150 is provided at the end of the magnetic member 110 so as to be aligned with the coil 130 along the winding axis of the coil 130. In this embodiment, two ferrite members 150 are provided, one at each end of the magnetic member 110. The two ferrite members 150 face each other with the coil 130 in between and have a symmetrical shape. In the following, mainly one of the two ferrite members 150 will be described, but a similar description applies to the other.

[0048] The ferrite member 150 is a plate-shaped member with an opening 153 formed therein, and is, for example, a ferrite bead made of a soft magnetic material. The ferrite member 150 is provided for purposes such as collecting magnetic flux from the magnet 10 and stabilizing the magnetic flux in the magnetic member 110. The ferrite member 150 is, for example, softer magnetic than the soft magnetic portion of the magnetic member 110, that is, it has lower coercivity. The end of the magnetic member 110 is located inside the opening 153. The opening 153 is a through hole that penetrates the ferrite member 150 along the winding axis direction.

[0049] The ferrite member 150 has a main body portion 151 and a protruding portion 152.

[0050] The main body 151 is positioned inside the columnar space A. The columnar space A is a space surrounded by imaginary planes that are assumed to be formed when the outer edge of the coil 130 is extended to both sides in the direction of the winding axis when viewed from the direction of the winding axis of the coil 130, and is sandwiched between two imaginary planes that are in contact with both ends of the magnetic member 110 in the direction of the winding axis and are perpendicular to the direction of the winding axis. In other words, the columnar space A is a space inside the outer edge of the coil 130 when viewed from the direction of the winding axis of the coil 130, sandwiched between two imaginary planes that are in contact with both ends of the magnetic member 110 in the direction of the winding axis and are perpendicular to the direction of the winding axis. Furthermore, the columnar space A has a rectangular cross-section when cut through the winding axis R1, and is a columnar space that is circumscribing the magnetic member 110 and the coil 130. The opening 153 is provided, for example, in the central part of the main body 151 when viewed from the direction of the winding axis.

[0051] The protrusion 152 is connected to the main body 151. The protrusion 152 is located on the outside of the columnar space A. The protrusion 152 is an example of a first protrusion located outside the coil 130 in a direction perpendicular to the winding axis. Also, the protrusion 152 is located on the opposite side of the coil 130 from the magnet 10 side.

[0052] Figure 3 shows an example of magnetic flux lines originating from the magnetic member 110 when the magnetic member 110 is magnetized by an external magnetic field (for example, a magnetic field formed by the magnet 10), indicated by a dashed line. When a ferrite member 150 is provided at the end of the magnetic member 110, magnetic flux emanates from the ferrite member 150, passing outside the magnetic member 110 from one end to the other. This magnetic flux, formed on the outside of the magnetic member 110 from one end to the other and originating from the magnetic member 110, is in the opposite direction to the magnetic flux inside the magnetic member 110. Therefore, when the magnetic flux originating from the magnetic member 110, formed on the outside of the magnetic member 110, passes through the coil 130, an electromotive force opposite to the electromotive force caused by the change in magnetic flux inside the magnetic member 110 is simultaneously generated in the coil 130. Since the ferrite member 150 has a protrusion 152, as shown in Figure 3, a portion of the magnetic flux exits from the protrusion 152. The protrusion 152, located outside the columnar space A, protrudes away from the coil 130, so the magnetic flux exiting from the protrusion 152 has difficulty passing through the coil 130. Therefore, by providing the ferrite member 150 with the protrusion 152, the magnetic flux passing through the coil 130 in the opposite direction to that inside the magnetic member 110 can be reduced. As a result, the power generated in the coil 130 increases, and the power generated by the power generation element 100 can be increased.

[0053] The ferrite member 150 is, for example, a resin molded body containing at least one of soft magnetic powder and hard magnetic powder, and a resin. Because the ferrite member 150 is a resin molded body, a ferrite member 150 with a shape such as a protrusion 152 can be easily formed. Furthermore, such a resin molded body can easily form ferrite members of various shapes, as described later, and offers greater freedom in shaping the ferrite member compared to conventional methods such as cutting.

[0054] Examples of soft magnetic powder materials include atomized powder and ferrite powder. Examples of hard magnetic powder materials include ferrite, neodymium magnets, Sm-Fe-N, and bicaloy powders. Examples of resins include nylon resins, polyamide resins, and polyphenylene sulfide resins.

[0055] The saturation magnetic flux density of the ferrite member 150 is greater than, for example, the saturation magnetic flux density of the magnetic member 110. Furthermore, the maximum residual magnetic flux density of the ferrite member 150 is greater than the maximum residual magnetic flux density of the magnetic member 110. This enhances the magnetic collection effect of the ferrite member 150.

[0056] Furthermore, the ferrite member 150 does not necessarily have to contain resin.

[0057] [Example 1] Next, a modified example of Embodiment 1 will be described. In the following description of this modified example, the differences from Embodiment 1 will be the main focus, and the similarities will be omitted or simplified.

[0058] Figure 5 is a cross-sectional view showing the schematic configuration of the power generation element 100a according to this modified example. The encoder according to this modified example is equipped with a power generation element 100a instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0059] As shown in Figure 5, the power generation element 100a differs from the power generation element 100 in that it includes a ferrite member 150a instead of a ferrite member 150.

[0060] The ferrite member 150a has a main body portion 151 positioned inside the columnar space A, and a projection portion 152a connected to the main body portion 151 and positioned outside the columnar space A. The projection portion 152a is an example of a first projection portion located outside the coil 130 in a direction perpendicular to the winding axis direction. The projection portion 152a is located on the opposite side of the coil 130 from the magnet 10 side.

[0061] A portion of the protrusion 152a is located closer to the center of the coil 130 than the main body 151, in the winding axis direction of the coil 130. The protrusion 152a covers a portion of the coil 130 from the side opposite to the magnet 10.

[0062] Figure 5, similar to Figure 3, shows an example of magnetic flux lines originating from the magnetic member 110 when the magnetic member 110 is magnetized by an external magnetic field, indicated by a dashed line. Because a portion of the protrusion 152a is located closer to the center of the coil 130 than the main body 151, the magnetic flux emanating from the protrusion 152a does not pass through the portion of the coil 130 that is covered by the protrusion 152a. Therefore, the magnetic flux passing through the coil 130 in the opposite direction to that inside the magnetic member 110 can be further reduced. As a result, the power generated in the coil 130 increases, and the power generated by the power generation element 100a can be increased.

[0063] [Differentiation 2] Next, a modified example of Embodiment 1, Part 2, will be described. In the following description of this modified example, the differences between Embodiment 1 and Modified Example 1 of Embodiment 1 will be the main focus, and the similarities will be omitted or simplified.

[0064] Figure 6 is a cross-sectional view showing the schematic configuration of the power generation element 100b according to this modified example. The encoder according to this modified example includes, for example, a power generation element 100b instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0065] As shown in Figure 6, the power generation element 100b differs from the power generation element 100 in that it includes a ferrite member 150b instead of a ferrite member 150.

[0066] The ferrite member 150b has a main body portion 151 positioned inside the columnar space A, and a projection portion 152b connected to the main body portion 151 and positioned outside the columnar space A. The projection portion 152b is an example of a first projection portion located outside the coil 130 in a direction perpendicular to the winding axis direction. The projection portion 152b is located on the opposite side of the coil 130 from the magnet 10 side.

[0067] A portion of the protrusion 152b, like the protrusion 152a, is located on the central side of the coil 130 in the winding axis direction of the coil 130, relative to the main body 151. The protrusion 152b covers a portion of the coil 130 from the side opposite to the magnet 10. Another portion of the protrusion 152b is located on the side opposite to the coil 130 side of the main body 151 in the winding axis direction of the coil 130. The other portion of the protrusion 152b is the part that protrudes outward along the winding axis direction, beyond the magnetic member 110 and the coil 130.

[0068] Figure 6, similar to Figure 3, shows an example of magnetic flux lines originating from the magnetic member 110 when the magnetic member 110 is magnetized by an external magnetic field, indicated by a dashed line. A portion of the protrusion 152b is located closer to the center of the coil 130 than the main body 151, achieving the same effect as the protrusion 152a. Furthermore, another portion of the protrusion 152b is located on the opposite side of the main body 151 from the coil 130, causing the magnetic flux emanating from the other portion of the protrusion 152b to pass further away from the coil 130. Therefore, the magnetic flux passing through the coil 130 in the opposite direction to the inside of the magnetic member 110 can be further reduced. Consequently, the power generated in the coil 130 increases, and the power generated by the power generation element 100b can be increased.

[0069] [Difference 3] Next, a modified example of Embodiment 1, Modification 3, will be described. In the following description of this modified example, the differences between Embodiment 1 and each of its modified examples will be the focus, and the explanation of the common points will be omitted or simplified.

[0070] Figure 7 is a cross-sectional view showing the schematic configuration of the power generation element 100c according to this modified example. The encoder according to this modified example includes, for example, a power generation element 100c instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0071] As shown in Figure 7, the power generation element 100c differs from the power generation element 100 in that it includes a ferrite member 150c instead of a ferrite member 150.

[0072] The ferrite member 150c has a main body portion 151 positioned inside the columnar space A, and a projection portion 152c connected to the main body portion 151 and positioned outside the columnar space A. The projection portion 152c is an example of a first projection portion located outside the coil 130 in a direction perpendicular to the winding axis direction. The projection portion 152c is located on the magnet 10 side of the coil 130.

[0073] Since the protrusion 152c is positioned closer to the magnet 10 than the main body 151, it can collect more magnetic flux from the magnet 10, thereby increasing the magnetic flux density when the magnetic member 110 is magnetized. As a result, the change in magnetic flux density in the magnetic member 110 becomes larger, the power generated in the coil 130 increases, and the power generated by the power generation element 100c can be increased.

[0074] Furthermore, since the protrusion 152c protrudes away from the coil 130, similar to the protrusion 152, the magnetic flux emanating from the protrusion 152c has difficulty passing through the coil 130. Therefore, an effect of increasing generated power, similar to that of the power generation element 100, can be expected.

[0075] [Differentiation Example 4] Next, a modified example of Embodiment 1, Part 4, will be described. In the following description of this modified example, the differences between Embodiment 1 and each of its modified examples will be the focus, and the explanation of the common points will be omitted or simplified.

[0076] Figure 8 is a cross-sectional view showing the schematic configuration of the power generation element 100d according to this modified example. The encoder according to this modified example includes, for example, the power generation element 100d instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0077] As shown in Figure 8, the power generation element 100d differs from the power generation element 100 in that it includes a ferrite member 150d instead of a ferrite member 150.

[0078] The ferrite member 150d has a main body portion 151 positioned inside the columnar space A, and a projection portion 152d connected to the main body portion 151 and positioned outside the columnar space A. The projection portion 152d is an example of a first projection portion located outside the coil 130 in a direction perpendicular to the winding axis direction. The projection portion 152d is located on the magnet 10 side of the coil 130.

[0079] A portion of the protrusion 152d is located closer to the center of the coil 130 than the main body 151, in the winding axis direction of the coil 130. The protrusion 152d covers a portion of the coil 130 from the magnet 10 side.

[0080] Since the protrusion 152d, like the protrusion 152c, is positioned closer to the magnet 10 than the main body 151, it collects more magnetic flux from the magnet 10. Furthermore, because a portion of the protrusion 152d extends toward the center of the coil 130, it can collect even more magnetic flux. Therefore, the power generated by the power generation element 100d can be increased.

[0081] Furthermore, since the protrusion 152d has the same shape as the protrusion 152a and is located outside the coil 130, the magnetic flux emanating from the protrusion 152d has difficulty passing through the coil 130. Therefore, the power generation element 100d can also be expected to have the same effect of increasing generated power as the power generation element 100a.

[0082] [Difference 5] Next, a modified example 5 of Embodiment 1 will be described. In the following description of this modified example, the differences between Embodiment 1 and each of its modified examples will be the focus, and the explanation of the common points will be omitted or simplified.

[0083] Figure 9 is a cross-sectional view showing the schematic configuration of the power generation element 100e according to this modified example. The encoder according to this modified example includes, for example, a power generation element 100e instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0084] As shown in Figure 9, the power generation element 100e differs from the power generation element 100 in that it includes a ferrite member 150e instead of a ferrite member 150.

[0085] The ferrite member 150e has a main body portion 151 positioned inside the columnar space A, and a projection portion 152e connected to the main body portion 151 and positioned outside the columnar space A. The projection portion 152e is an example of a first projection portion located outside the coil 130 in a direction perpendicular to the winding axis direction. The projection portion 152e is located on the magnet 10 side of the coil 130.

[0086] A portion of the protrusion 152e is located closer to the center of the coil 130 than the main body 151 in the winding axis direction of the coil 130. The protrusion 152e covers a portion of the coil 130 from the magnet 10 side. Another portion of the protrusion 152e is located on the opposite side of the main body 151 from the coil 130 side in the winding axis direction of the coil 130. The other portion of the protrusion 152e is the part that protrudes outward from the magnetic member 110 and the coil 130 along the winding axis direction.

[0087] Since the protrusion 152e, like the protrusion 152c, is positioned closer to the magnet 10 than the main body 151, it collects more magnetic flux from the magnet 10. Furthermore, since part and other parts of the protrusion 152e are positioned to extend along the winding axis, even more magnetic flux can be collected. Therefore, the power generated by the power generation element 100e can be increased.

[0088] Furthermore, since the protrusion 152e has the same shape as the protrusion 152b and is located outside the coil 130, the magnetic flux emanating from the protrusion 152e has difficulty passing through the coil 130. Therefore, the power generation element 100e can also be expected to have the same effect of increasing generated power as the power generation element 100b.

[0089] [Modification 6] Next, a modified example 6 of Embodiment 1 will be described. In the following description of this modified example, the differences between Embodiment 1 and each of its modified examples will be explained, and the explanation of the common points will be omitted or simplified.

[0090] Figure 10 is a cross-sectional view showing the schematic configuration of the power generation element 100f according to this modified example. The encoder according to this modified example includes, for example, a power generation element 100f instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0091] As shown in Figure 10, the power generation element 100f differs from the power generation element 100 in that it includes a ferrite member 150f instead of a ferrite member 150.

[0092] The ferrite member 150f has a main body portion 151 positioned inside the columnar space A, and a projection portion 152f connected to the main body portion 151 and positioned outside the columnar space A. The projection portion 152f is an example of a second projection portion located outside the end of the magnetic member 110 in the winding axis direction. The projection portion 152f is positioned to extend from the main body portion 151 on the side opposite to the coil 130 side of the main body portion 151, along the winding axis direction.

[0093] Because the protrusion 152f extends outward beyond the end of the magnetic member 110, the ferrite member 150f can collect more magnetic flux from the magnet 10, thereby increasing the magnetic flux density when the magnetic member 110 is magnetized. Therefore, the power generated by the power generation element 100f can be increased with the same effect as the power generation element 100c.

[0094] Furthermore, since the magnetic flux originating from the magnetic member 110 also emanates from the protruding portion 152f, the magnetic flux emanating from the main body portion 151, which is close to the coil 130, is reduced, and the magnetic flux passing through the coil 130 in the opposite direction to that inside the magnetic member 110 can be reduced. As a result, the power generated in the coil 130 increases, and the power generated by the power generation element 100f can be increased.

[0095] [Difference 7] Next, we will describe Modification 7 of Embodiment 1. In the following description of this modification, we will focus on explaining the differences between Embodiment 1 and each of its modifications, and will omit or simplify the explanation of the common points.

[0096] Figure 11 is a cross-sectional view showing the schematic configuration of the power generation element 100g according to this modified example. The encoder according to this modified example includes, for example, a power generation element 100g instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0097] As shown in Figure 11, the power generation element 100g differs from the power generation element 100 in that it includes a ferrite member 150g instead of the ferrite member 150.

[0098] The ferrite member 150g has a main body portion 151 positioned inside the columnar space A, and a projection portion 152g connected to the main body portion 151 and positioned outside the columnar space A. An opening 153g is formed in the ferrite member 150g. The opening 153g is provided, for example, in the center of the main body portion 151 when viewed from the winding axis direction. The opening 153g is a bottomed hole that penetrates the main body portion 151 and has its bottom formed by the projection portion 152g. The end of the magnetic member 110 is located inside the opening 153g.

[0099] The protrusion 152g is an example of a second protrusion located outside the end of the magnetic member 110 in the winding axis direction. The protrusion 152g extends from the main body 151 on the side opposite to the coil 130 side of the main body 151, along the winding axis direction. The protrusion 152g covers the end of the magnetic member 110 from the outside in the winding axis direction.

[0100] The protrusion 152g covers the end of the magnetic member 110, allowing the ferrite member 150g to collect more magnetic flux from the magnet 10, thereby increasing the magnetic flux density when the magnetic member 110 is magnetized. As a result, the power generated by the power generation element 100g can be increased with the same effect as the power generation element 100c.

[0101] Furthermore, since the magnetic flux originating from the magnetic member 110 also emanates from the protruding portion 152g, the magnetic flux emanating from the main body portion 151, which is close to the coil 130, is reduced, and the magnetic flux passing through the coil 130 in the opposite direction to that inside the magnetic member 110 can be reduced. As a result, the power generated in the coil 130 increases, and the power generated by the power generation element 100g can be increased.

[0102] (Embodiment 2) Next, Embodiment 2 will be described. In the following description of this embodiment, the differences from Embodiment 1 will be the main focus, and the similarities will be omitted or simplified.

[0103] Figure 12 is a cross-sectional view showing the schematic configuration of the power generation element 200 according to this embodiment. The encoder according to this embodiment, for example, is equipped with a power generation element 200 instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0104] As shown in Figure 12, the power generation element 200 differs from the power generation element 100 in that it includes a ferrite member 250 instead of a ferrite member 150.

[0105] The ferrite member 250 encloses the magnetic member 110. Specifically, the ferrite member 250 has an opening 253 formed at its center when viewed from the winding axis direction, and the magnetic member 110 is located within the opening 253. The ferrite member 250 is a member having a cylindrical main body portion 251 through which the opening 253 passes.

[0106] In the winding axis direction, the length of the main body 251 is, for example, the same as the length of the magnetic member 110. In the winding axis direction, the length of the main body 251 may be longer or shorter than the length of the magnetic member 110. The main body 251 covers the entire outer circumference of the magnetic member 110 when viewed from the winding axis direction. Also, in the winding axis direction, the length of the main body 251 is, for example, longer than the length of the coil 130.

[0107] In the power generation element 200, the coil 130 is wound around the ferrite member 250. In the power generation element 200, the coil 130, ferrite member 250, and magnetic member 110 are arranged from the outside in a direction perpendicular to the winding axis.

[0108] In the power generation element 200, the coil 130 is wound around a ferrite member 250 that covers the outer circumference of the magnetic member 110 when viewed from the winding axis direction. As a result, the surface area of ​​the ferrite member 250 increases, allowing the ferrite member 250 to collect more magnetic flux from the magnet 10. Therefore, the magnetic flux density when the magnetic member 110 is magnetized can be increased, and the power generated by the power generation element 200 can be increased.

[0109] [Example 1] Next, we will describe a modified example 1 of Embodiment 2. In the following description of this modified example, we will focus on the differences between Embodiment 1 and Embodiment 2, and omit or simplify the explanation of the common points.

[0110] Figure 13 is a cross-sectional view showing the schematic configuration of the power generation element 200a according to this modified example. The encoder according to this modified example includes, for example, a power generation element 200a instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0111] As shown in Figure 13, the power generation element 200a differs from the power generation element 200 in that it includes a ferrite member 250a instead of a ferrite member 250.

[0112] The ferrite member 250a has a cylindrical main body portion 251 that encloses the magnetic member 110, and flange-shaped first flange portion 255 and second flange portion 256 provided at both ends of the main body portion 251 in the winding axis direction. The coil 130 is located between the first flange portion 255 and the second flange portion 256.

[0113] The first flange portion 255 is a plate that is erected from one end of the main body portion 251 in a direction perpendicular to the winding axis direction. The second flange portion 256 is a plate that is erected from the other end of the main body portion 251 in a direction perpendicular to the winding axis direction. The first flange portion 255 and the second flange portion 256 are, for example, the same shape.

[0114] Thus, because the ferrite member 250a has a first flange portion 255 and a second flange portion 256 in addition to the main body portion 251, the surface area of ​​the ferrite member 250a is further increased, and the ferrite member 250a can collect more magnetic flux from the magnet 10. Therefore, the magnetic flux density when the magnetic member 110 is magnetized can be increased, and the power generated by the power generation element 200a can be increased.

[0115] (Embodiment 3) Next, Embodiment 3 will be described. In the following description of this embodiment, the differences from Embodiments 1 and 2 will be the main focus, and the similarities will be omitted or simplified.

[0116] Figure 14 is a cross-sectional view showing the schematic configuration of the power generation element 300 according to this embodiment. The encoder according to this embodiment, for example, is equipped with the power generation element 300 instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0117] As shown in Figure 14, the power generation element 300 differs from the power generation element 100 in that it includes a coil 330 instead of a coil 130, and a ferrite member 350 instead of a ferrite member 150.

[0118] The coil 330 is a coil in which the conductors constituting the coil 330 are wound around the magnetic member 110. In the winding axis direction, the outer diameter of the ends of the coil 330 is smaller than the outer diameter of the central part of the coil 330. In this specification, the outer diameter is the outer diameter when viewed from the winding axis direction. The ends and central part of the coil 330 refer to the ends and central part of the winding portion in which the coil 330 is wound around the magnetic member 110. In this embodiment, in the winding axis direction, the number of turns per unit length at the ends of the coil 330 is less than the number of turns per unit length at the central part of the coil 330. Note that the coil 330 does not need to have the above-mentioned relationship of the number of turns per unit length as long as the outer diameter of the ends of the coil 330 is smaller than the outer diameter of the central part of the coil 330 in the winding axis direction. For example, the outer diameter of the end of the coil 330 may be smaller than the outer diameter of the central part of the coil 330 in the winding axis direction by changing the shape of the magnetic member 110 or by providing a spacer or the like between the magnetic member 110 and the coil.

[0119] The ferrite member 350 is the same as the ferrite member 150 except that it does not have the protruding portion 152. In other words, the ferrite member 350 is a component of the ferrite member 150 that is composed of the main body portion 151. Note that the ferrite member 350 is not limited to this example, and may be any of the ferrite members according to Embodiment 1, each of the modifications of Embodiment 1, and Embodiment 2 described above.

[0120] Figure 14, similar to Figure 3, shows an example of magnetic flux lines originating from the magnetic member 110 when the magnetic member 110 is magnetized by an external magnetic field, indicated by a dashed line. As shown in Figure 14, near both ends of the magnetic member 110 in the winding axis direction, the magnetic flux formed on the outside of the magnetic member 110, from one end to the other, tends to pass relatively close to the magnetic member 110. In the winding axis direction, the outer diameter of the end of the coil 330 is smaller than the outer diameter of the central part of the coil 330, so the coil 330 is positioned to avoid the magnetic flux formed on the outside of the magnetic member 110 as described above. Therefore, the magnetic flux passing through the coil 330 in the opposite direction to that inside the magnetic member 110 can be reduced. Thus, the power generated in the coil 330 increases, and the power generated by the power generation element 300 can be increased.

[0121] (Embodiment 4) Next, Embodiment 4 will be described. In the following description of this embodiment, the differences from Embodiments 1 to 3 will be the main focus, and the similarities will be omitted or simplified.

[0122] Figure 15 is a cross-sectional view showing the schematic configuration of the power generation element 400 according to this embodiment. The encoder according to this embodiment, for example, is equipped with the power generation element 400 instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0123] As shown in Figure 15, the power generation element 400 differs from the power generation element 100 in that it includes a ferrite member 350 instead of a ferrite member 150, and further includes a magnetic member 460 and a coil 470. In this embodiment, coil 130 is an example of a first coil, and coil 470 is an example of a second coil.

[0124] Unlike the magnetic member 110, the magnetic member 460 is a magnetic member that does not produce the Great Barkhausen effect. The magnetic member 460 is not particularly limited as long as it is a ferromagnetic magnetic member used as a core material for a coil, such as an iron core. The magnetic member 460 actively collects the magnetic flux originating from the magnetization of the magnetic member 110 that is formed on the outside of the magnetic member 110 from one end to the other in the winding axis direction of the magnetic member 110.

[0125] The magnetic member 460, like the magnetic member 110, is an elongated member whose winding axis direction is in the longitudinal direction of the coil 130. The magnetic member 460 is positioned opposite the magnetic member 110 and the coil 130 to the magnet 10 side, facing the magnetic member 110 and the coil 130. The magnetic member 460 is placed on the coil 130, for example, when the coil 470 is wound around it.

[0126] Coil 470 is a coil in which the conductors constituting coil 470 are wound around the magnetic member 460. Specifically, coil 470 is wound along a winding axis R2 that passes through the center of the magnetic member 460. Winding axis R2 is parallel to winding axis R1. Coil 470 is positioned opposite to magnetic member 110 and coil 130, on the side of magnetic member 110 and coil 130 that is opposite to the magnet 10. Coil 470 is, for example, placed on coil 130. Magnetic member 110, coil 130, magnetic member 460 and coil 470 are aligned along the alignment direction indicated by arrow Z.

[0127] The magnetic member 460 and the coil 470 are positioned where a magnetic field is formed by the magnetic member 110, which is magnetized by an external magnetic field such as the magnet 10. Specifically, the magnetic member 460 and the coil 470 are positioned where the magnetic flux originating from the magnetic member 110, which is formed on the outside of the magnetic member 110, passes from one end to the other in the winding axis direction of the magnetic member 110. Therefore, the magnetic member 460 and the coil 470 are positioned where the magnetic flux passes in the opposite direction to that inside the magnetic member 110. As a result, the coil 470 generates electricity together with the coil 130 due to the change in the magnetic flux of the magnetic member 110.

[0128] Coil 130 and coil 470 are electrically connected in series, for example. Specifically, the wires constituting coil 130 and the wires constituting coil 470 are electrically connected in series such that the currents generated in coil 130 and coil 470, respectively, due to the change in magnetic flux of the magnetic member 110, do not cancel each other out. For example, if the winding directions of the wires of coil 130 and coil 470 are opposite, the current flows in the same direction, so the wires of coil 130 drawn from one end in the winding axis direction and the wires of coil 470 drawn from the other end are connected, thereby connecting them in series. Also, for example, if the winding directions of the wires of coil 130 and coil 470 are the same, the wires of coil 130 drawn from one end in the winding axis direction and the wires of coil 470 drawn from the same end are connected, thereby connecting them in series. The wires drawn from the ends of coil 130 and coil 470 that are not connected to each other are connected to terminals 181 and 182. Note that coil 130 and coil 470 may be electrically connected in parallel.

[0129] With this configuration, in the power generation element 400, the magnetic flux emitted from the magnetic member 110 due to the magnetization of the magnetic member 110 causes the coil 470 to generate electricity simultaneously with the coil 130, thereby increasing the power generated by the power generation element 400. On the other hand, it is conceivable to increase the power generated by the coil 130 by simply increasing the number of turns of the coil 130, but if the coil 130 becomes thicker, the conductor of the coil 130 will also exist in a position where magnetic flux passes in the opposite direction to that inside the magnetic member 110, outside the magnetic member 110. Therefore, if magnetic flux passes in the opposite direction to that inside the magnetic member 110 through a part of the coil 130, an electromotive force opposite to that caused by the change in magnetic flux inside the magnetic member 110 will be generated simultaneously, and the amount of power generated cannot be effectively increased. For this reason, as in the power generation element 400, by having the coil 470 generate electricity together with the coil 130, the power generated can be effectively increased without canceling out the electromotive force of the coil 130.

[0130] (Embodiment 5) Next, Embodiment 5 will be described. In the following description of this embodiment, the differences from Embodiments 1 to 4 will be the main focus, and the similarities will be omitted or simplified.

[0131] Figure 16 is a cross-sectional view showing the schematic configuration of the power generation element 500 according to this embodiment. The encoder according to this embodiment, for example, is equipped with the power generation element 500 instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0132] As shown in Figure 16, the power generation element 500 differs from the power generation element 100 in that it includes a magnetic member 510 instead of a magnetic member 110, and a ferrite member 350 instead of a ferrite member 150.

[0133] The magnetic member 510 comprises a composite magnetic wire 511 having different magnetic properties in its central and outer peripheral portions, and a coating layer 512 covering the outer circumference of the composite magnetic wire 511. The magnetic member 510 is a magnetic member that produces the Great Barkhausen effect due to changes in the external magnetic field. The composite magnetic wire 511 is, for example, a Wiegand wire, as described above as a composite magnetic wire that can be used in the magnetic member 110. In the composite magnetic wire, one of the central and outer peripheral portions in the radial direction is a hard magnetic portion, and the other is a soft magnetic portion.

[0134] The coating layer 512 covers, for example, the entire radial surface of the composite magnetic wire 511. The coating layer 512 is made of a soft magnetic material. The coercivity of the coating layer 512 is, for example, equivalent to the coercivity of the soft magnetic portion of the composite magnetic wire 511. Examples of materials that make up the coating layer 512 include Fe-Ni, Fe-Si, Fe-Si-Al, Fe-Si-B, and Co-Fe-Si-B.

[0135] The coating layer 512 is formed using, for example, physical vapor deposition (PVD) methods such as sputtering, ion plating, and vacuum deposition, chemical vapor deposition (CVD), or plating methods.

[0136] As described above, the large Barkhausen jump occurs when the magnetization direction of the soft magnetic portion of the composite magnetic wire 511 is rapidly reversed. Therefore, the larger the magnetic flux of the soft magnetic portion, the greater the change in magnetic flux density during the large Barkhausen jump, and the greater the power generated by the coil 130 associated with the large Barkhausen jump. As a result, in the magnetic member 510, the magnetization of the coating layer 512 rapidly reverses together with the soft magnetic portion of the composite magnetic wire 511, increasing the power generated by the coil 130 and thus increasing the power generated by the power generation element 500.

[0137] (Embodiment 6) Next, Embodiment 6 will be described. In the following description of this embodiment, the differences from Embodiments 1 to 5 will be the main focus, and the explanation of the common points will be omitted or simplified.

[0138] Figure 17 shows a cross-sectional view and a top view illustrating the schematic configuration of the magnetic member 610 according to this embodiment. Specifically, Figure 17(a) is a cross-sectional view of the magnetic member 610, and Figure 17(b) is a top view of the magnetic member 610 as seen from above in Figure 17(a). Figure 17(a) shows a cross-section at the position indicated by the line XVIIa-XVIIa in Figure 17(b). The encoder according to this embodiment includes, for example, a power generation element using the magnetic member 610 instead of the power generation element 100 of the encoder 1 according to Embodiment 1. The power generation element according to this embodiment includes, for example, a magnetic member 610 instead of the magnetic member 510 according to Embodiment 5. Note that the magnetic member 610 according to this embodiment may be used in place of the magnetic member according to any of Embodiments 1 to 4.

[0139] As shown in Figure 17, the magnetic member 610 has a plurality of first magnetic-sensitive layers 611 and a plurality of second magnetic-sensitive layers 612 that are harder magnetic than the plurality of first magnetic-sensitive layers 611. The magnetic member 610 is a magnetic member that produces the Great Barkhausen effect in response to changes in the external magnetic field.

[0140] Multiple first magnetic-sensitive layers 611 and multiple second magnetic-sensitive layers 612 are stacked alternately along a direction that intersects (specifically, is perpendicular to) the winding axis direction indicated by arrow X. In the illustrated example, the multiple first magnetic-sensitive layers 611 and multiple second magnetic-sensitive layers 612 are stacked along the alignment direction indicated by arrow Z.

[0141] The total thickness of the multiple first magnetic-sensitive layers 611 is greater than the total thickness of the multiple second magnetic-sensitive layers 612.

[0142] Furthermore, the thickness of each first magnetic-sensitive layer 611 may be greater than the thickness of each second magnetic-sensitive layer 612. Also, the thicknesses of the multiple first magnetic-sensitive layers 611 may be the same, for example, but may differ from one another. Similarly, the thicknesses of the multiple second magnetic-sensitive layers 612 may be the same, for example, but may differ from one another.

[0143] Furthermore, in the illustrated example, the number of multiple first magnetic-sensitive layers 611 and multiple second magnetic-sensitive layers 612 is three each, but it may be two or four or more. Also, the number of multiple first magnetic-sensitive layers 611 and the number of multiple second magnetic-sensitive layers 612 may be different. For example, both the uppermost and lowermost parts of the magnetic member 610 may be first magnetic-sensitive layers 611.

[0144] The shape of the magnetic member 610 when viewed from the stacking direction is, for example, a rectangle with approximately equal length and width, but it may also be a circular or polygonal shape.

[0145] Multiple first magnetic-sensitive layers 611 and multiple second magnetic-sensitive layers 612 are laminated by forming films using methods such as sputtering, ion plating, and vacuum deposition (PVD), CVD, or plating.

[0146] Examples of materials that constitute the multiple first magnetic-sensitive layers 611 include Fe-Ni, Fe-Si, Fe-Si-Al, Fe-Si-B, and Co-Fe-Si-B.

[0147] The material constituting the multiple second magnetic-sensitive layers 612 is, for example, the same material as the material constituting the multiple first magnetic-sensitive layers 611. For example, by depositing the multiple second magnetic-sensitive layers 612 under different deposition conditions than when depositing the multiple first magnetic-sensitive layers 611, the coercivity is changed, forming multiple second magnetic-sensitive layers 612 that have higher coercivity and are hard magnetic than the multiple first magnetic-sensitive layers 611. For example, when depositing multiple first magnetic-sensitive layers 611 and multiple second magnetic-sensitive layers 612 by sputtering, the coercivity is changed by changing the deposition conditions such as vacuum level, temperature, and deposition rate. When changing the vacuum level as a deposition condition, for example, within a certain range of vacuum levels, the coercivity of the multiple second magnetic-sensitive layers 612 can be increased by using a higher vacuum level when depositing the multiple second magnetic-sensitive layers 612 than when depositing the multiple first magnetic-sensitive layers 611.

[0148] Furthermore, the materials constituting the multiple second magnetic-sensitive layers 612 may be different from the materials constituting the multiple first magnetic-sensitive layers 611. Examples of materials constituting the multiple second magnetic-sensitive layers 612 in this case include Fe and Fe-Co. In addition, the materials constituting the multiple second magnetic-sensitive layers 612 may be alloys of the same combination of metals as the materials constituting the multiple first magnetic-sensitive layers 611, but with a different composition from the materials constituting the multiple first magnetic-sensitive layers 611.

[0149] In the magnetic member 610 having the above configuration, since the multiple first magnetic-sensitive layers 611 are softer in magnetism than the multiple second magnetic-sensitive layers 612, as explained above in the description of the Great Barkhausen effect, a change in the external magnetic field causes a rapid reversal of the magnetization direction of the multiple first magnetic-sensitive layers 611, generating a power generation pulse in the coil 130 wound around the magnetic member 610. In the magnetic member 610, the total thickness of the multiple first magnetic-sensitive layers 611, which are softer in magnetism than the multiple second magnetic-sensitive layers 612, is greater, resulting in a larger power generation in the coil 130, and thus increasing the power generation of the power generation element using the magnetic member 610. Furthermore, because the first magnetic-sensitive layers 611 and the second magnetic-sensitive layers 612 are stacked alternately, the first magnetic-sensitive layers 611 and the second magnetic-sensitive layers 612 interact more easily, making the Great Barkhausen effect more likely to occur, thus increasing power generation more effectively than simply increasing the thickness of the second magnetic-sensitive layers 612.

[0150] Furthermore, the power generation element may be provided with multiple magnetic members 610. The multiple magnetic members 610 may be used, for example, stacked together.

[0151] [Example 1] Next, we will describe a modified example 1 of Embodiment 6. In the following description of this modified example, we will focus on the differences from Embodiments 1 to 6, and omit or simplify the explanation of the common points.

[0152] Figure 18 is a diagram showing a cross-sectional view and a top view illustrating the schematic configuration of the magnetic member 610a according to this embodiment. Specifically, Figure 18(a) is a cross-sectional view of the magnetic member 610a, and Figure 18(b) is a top view of the magnetic member 610a as seen from above in Figure 18(a). Figure 18(a) shows a cross-section at the position indicated by the line XVIIIa-XVIIIa in Figure 18(b). The magnetic member 610a according to this modified example can be used, for example, in place of the magnetic member 610 according to Embodiment 6.

[0153] As shown in Figure 18, the magnetic member 610a has a plurality of first magnetic-sensitive layers 611a and a plurality of second magnetic-sensitive layers 612a that are harder magnetic than the plurality of first magnetic-sensitive layers 611a. The magnetic member 610a is a magnetic member that produces the Great Barkhausen effect in response to changes in the external magnetic field. The magnetic member 610a has the same configuration as the magnetic member 610 except that its shape when viewed from the stacking direction is different.

[0154] When viewed from the stacking direction, the shape of the magnetic member 610a is a long rectangle. The longitudinal direction of the magnetic member 610a is the same direction as the winding axis direction. Also, the longitudinal direction of the magnetic member 610a is, for example, perpendicular to the alignment direction. When viewed from the stacking direction, the length of the magnetic member 610a in the longitudinal direction is, for example, more than twice the length of the magnetic member 610a in the short direction.

[0155] Thus, because the shape of the magnetic member 610a when viewed from the stacking direction is elongated, it can be magnetized in the longitudinal direction, which allows for a larger change in magnetic flux density due to the reversal of the magnetization direction when a large Barkhausen jump occurs. As a result, the power generated in the coil 130 increases, and the power generated by the power generation element using the magnetic member 610a can be increased.

[0156] [Differentiation 2] Next, a modified example of Embodiment 6, Part 2, will be described. In the following description of this modified example, the differences from Embodiments 1 to 6 will be the main focus, and the commonalities will be omitted or simplified.

[0157] Figure 19 is a diagram showing a cross-sectional view and a top view illustrating the schematic configuration of the magnetic member 610b according to this embodiment. Specifically, Figure 19(a) is a cross-sectional view of the magnetic member 610b, and Figure 19(b) is a top view of the magnetic member 610b as seen from above in Figure 19(a). Figure 19(a) shows a cross-section at the position indicated by the line XIXa-XIXa in Figure 19(b). The magnetic member 610b according to this modified example can be used, for example, in place of the magnetic member 610 according to Embodiment 6.

[0158] As shown in Figure 19, the magnetic member 610b has a plurality of first magnetic-sensitive layers 611b and a plurality of second magnetic-sensitive layers 612b that are harder magnetic than the plurality of first magnetic-sensitive layers 611b. The magnetic member 610b is a magnetic member that produces the Great Barkhausen effect in response to changes in the external magnetic field. The magnetic member 610b has the same configuration as the magnetic member 610 except that its shape when viewed from the stacking direction is different.

[0159] When viewed from the stacking direction, the shape of the magnetic member 610b is elliptical in its outer shape. The major axis of the ellipse of the magnetic member 610b extends in the direction of the winding axis. In addition, the major axis of the ellipse of the magnetic member 610b extends, for example, in a direction perpendicular to the alignment direction.

[0160] Furthermore, the magnetic member 610b has an opening 613b that penetrates the central part of the magnetic member 610b in the stacking direction when viewed from the stacking direction. The shape of the opening 613b when viewed from the stacking direction is elliptical, but it may be other shapes such as rectangles. The major axis of the ellipse of the opening 613b extends in the direction of the winding axis. When viewed from the stacking direction, the opening 613b is similar in shape to, for example, the outer circumference of the magnetic member 610b.

[0161] Thus, due to the elliptical shape of the magnetic member 610b when viewed from the stacking direction, the width of the central part is greater than the width of the ends in the winding axis direction. Normally, when the magnetic member 610b is magnetized by an external magnetic field, the central part is more easily magnetized because a stronger magnetic field is applied there, while the ends may hardly be magnetized at all. In particular, if the magnetization of the hard magnetic second magnetic-sensitive layer 612b is insufficient, the magnetization direction of the first magnetic-sensitive layer 611b cannot be maintained until a large Barkhausen jump occurs, and the large Barkhausen jump will mainly occur in the central part of the magnetic member 610b. Therefore, by increasing the width of the central part of the magnetic member 610b, where a strong magnetic field is easily applied, the volume of the part in the magnetic member 610b where the large Barkhausen jump occurs increases. As a result, the power generated in the coil 130 increases, and the power generated by the power generation element using the magnetic member 610b can be increased.

[0162] (Embodiment 7) Next, Embodiment 7 will be described. In the following description of this embodiment, the differences from Embodiments 1 to 6 will be the main focus, and the similarities will be omitted or simplified.

[0163] Figure 20 is a cross-sectional view showing the schematic configuration of the power generation element 700 according to this embodiment. The encoder according to this embodiment, for example, is equipped with the power generation element 700 instead of the power generation element 100 of the encoder 1 according to Embodiment 1.

[0164] As shown in Figure 20, the power generation element 700 differs from the power generation element 500 according to Embodiment 5 in that it includes a magnetic member 710 instead of the magnetic member 510.

[0165] The magnetic member 710 has a first magnetic-sensitive portion 711 and a second magnetic-sensitive portion 712 having different magnetic properties from the first magnetic-sensitive portion 711. The magnetic member 710 is a magnetic member that produces the Great Barkhausen effect in response to changes in the external magnetic field. The cross-sectional shape of the magnetic member 710 when cut radially is, for example, circular or elliptical, but may also be other shapes such as rectangular or polygonal. The magnetic member 710 is, for example, a long member in which the winding axis direction of the coil 130 is the longitudinal direction.

[0166] The first magnetic-sensitive portion 711 and the second magnetic-sensitive portion 712 each extend in the direction of the winding axis. Both the first magnetic-sensitive portion 711 and the second magnetic-sensitive portion 712 are elongated in the direction of the winding axis. In detail, the first magnetic-sensitive portion 711 is wire-shaped and extends in the direction of the winding axis, and the second magnetic-sensitive portion 712 is cylindrical and extends in the direction of the winding axis. The second magnetic-sensitive portion 712 covers the outer surface of the first magnetic-sensitive portion 711 when viewed from the direction of the winding axis, in other words, the surface that extends along the winding axis. The first magnetic-sensitive portion 711 and the second magnetic-sensitive portion 712 are aligned in a direction that intersects (for example, perpendicular to) the winding axis.

[0167] In this embodiment, of the first magnetic-sensitive portion 711 and the second magnetic-sensitive portion 712, one is a hard magnetic portion with a higher coercivity than the other, and the other is a soft magnetic portion. In the magnetic member 710, the first magnetic-sensitive portion 711 may be a hard magnetic portion, and the second magnetic-sensitive portion 712 may be a hard magnetic portion. The first magnetic-sensitive portion 711 and the second magnetic-sensitive portion 712 are composed of different materials, for example. Examples of materials that constitute the hard magnetic portion include magnetic materials with a coercivity of 60 Oe or more. Examples of materials that constitute the soft magnetic portion include magnetic materials with a coercivity of 20 Oe or less.

[0168] The magnetic member 710 used in the power generation element 700 is a magnetic member manufactured by one of the following manufacturing method examples.

[0169] [Manufacturing method example 1] First, let's describe Example 1 of the manufacturing method for the magnetic member 710. Figure 21 is a flowchart of Example 1 of the manufacturing method for the magnetic member 710.

[0170] As shown in Figure 21, in manufacturing method example 1, first, a cylindrical magnetic material is prepared (step S11). The cylindrical magnetic material is the component that will become the second magnetic sensing part 712 described above, and is a long cylindrical body having an opening that penetrates in the longitudinal direction.

[0171] Next, a magnetic material having different magnetic properties from the magnetic material is injected into the interior of the cylindrical magnetic body (step S12). This forms the first magnetic-sensitive portion 711 described above. The magnetic material includes, for example, magnetic powder and resin. The magnetic member 710 is formed by insert molding, injecting such a magnetic material into the interior (opening) of the cylindrical magnetic body. Alternatively, the magnetic member 710 may be formed by injecting a magnetic material composed of magnetic powder into the interior of the cylindrical magnetic body and sintering the magnetic powder.

[0172] By forming the magnetic member 710 using this manufacturing method, the magnetic member 710 can be manufactured in a simplified process without having to go through steps such as twisting the magnetic member under predetermined conditions.

[0173] Furthermore, the size of the soft magnetic portion, which is one of the first magnetic sensing portion 711 and the second magnetic sensing portion 712, can be easily adjusted. By making the soft magnetic portion of an appropriate size (for example, a soft magnetic portion with a larger radial cross-sectional area than the hard magnetic portion), the power generated in the coil 130 can be increased, and the power generated by the power generation element 700 can be increased.

[0174] Furthermore, when a hard magnetic portion and a soft magnetic portion are formed by twisting a magnetic member, the magnetic properties may be non-uniform in the hard magnetic portion and the soft magnetic portion. In the magnetic member 710, the magnetic properties of the first magnetic-sensitive portion 711 and the second magnetic-sensitive portion 712 can be determined by the material used. As a result, the uniformity of the magnetic properties within each of the first magnetic-sensitive portion 711 and the second magnetic-sensitive portion 712 is high, and the amount of change in the magnetic flux density of the magnetic member 710 in the large Barkhausen jump is stabilized. Therefore, the variation in the power generated by the power generation element 700 can be reduced.

[0175] [Manufacturing method example 2] Next, we will describe Example 2 of the manufacturing method for the magnetic member 710. Figure 22 is a flowchart of Example 2 of the manufacturing method for the magnetic member 710.

[0176] As shown in Figure 22, in manufacturing method example 2, first, a wire-shaped magnetic material is prepared (step S21). The wire-shaped magnetic material is a long wire that will become the first magnetically sensitive part 711 described above.

[0177] Next, the radial outer surface of the wire-shaped magnetic material is coated with a magnetic material having different magnetic properties from that of the magnetic material (step S22). This forms the second magnetic-sensitive portion 712 described above. Examples of methods for coating the surface of the magnetic material with a magnetic material include physical vapor deposition (PVD) methods such as sputtering, ion plating, and vacuum deposition, chemical vapor deposition (CVD), or plating.

[0178] By forming the magnetic member 710 using this manufacturing method, the magnetic member 710 can be manufactured in a simplified process without having to go through steps such as twisting the magnetic member under predetermined conditions.

[0179] Furthermore, similar to the manufacturing method example 1, the size of the soft magnetic part, which is one of the first magnetic-sensitive part 711 and the second magnetic-sensitive part 712, can be easily adjusted. By making the soft magnetic part of an appropriate size, the power generated in the coil 130 can be increased, and the power generated by the power generation element 700 can be increased. In addition, the magnetic properties of the first magnetic-sensitive part 711 and the second magnetic-sensitive part 712 can be determined by the material used. As a result, the uniformity of the magnetic properties inside the first magnetic-sensitive part 711 and the second magnetic-sensitive part 712 is high, and the amount of change in the magnetic flux density of the magnetic member 710 in the large Barkhausen jump is stabilized. Thus, the variation in the power generated by the power generation element 700 can be reduced.

[0180] (Other embodiments) The power generation element and encoder related to this disclosure have been described above based on embodiments, but this disclosure is not limited to the above embodiments. This disclosure also includes forms that can be obtained by applying various modifications to each of the above embodiments that a person skilled in the art can conceive, and forms that can be realized by arbitrarily combining components and functions from different embodiments without departing from the spirit of this disclosure.

[0181] For example, the above embodiment described an example of a rotary encoder used in combination with a motor, but it is not limited to this. The technology of this disclosure can also be applied to linear encoders. [Industrial applicability]

[0182] The power generation elements and encoders related to this disclosure are useful for motors and other devices and equipment that rotate or move linearly. [Explanation of symbols]

[0183] 1 encoder 10 Magnets 20 Rotating Plates 30 Rotation axis 40 circuit boards 50 Control circuits 60 memory 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 200, 200a, 300, 400, 500, 700 Power generation elements 110, 460, 510, 610, 610a, 610b, 710 Magnetic material 130, 330, 470 coils 150, 150a, 150b, 150c, 150d, 150e, 150f, 150g, 250, 250a, 350 Ferrite members 151, 251 Main body 152, 152a, 152b, 152c, 152d, 152e, 152f, 152g protrusion 153, 153g, 253, 613b opening Terminals 181 and 182 190 cabinets 255 First guard section 256 Second guard section 511 Composite magnetic wire 512 Covering layer 611, 611a, 611b first magnetically sensitive layer 612, 612a, 612b second magnetically sensitive layer 711 1st magnetically sensitive part 712 Second magnetically sensitive part A columnar space R1, R2 winding shaft

Claims

1. A magnetic component that produces the Great Barkhausen effect due to changes in the external magnetic field formed by a magnetic field source, The coil wound around the magnetic member, The magnetic member comprises a ferrite member provided at the end of the magnetic member so as to be adjacent to the coil, The ferrite member has a main body and a protruding portion that extends from the main body. The main body is surrounded by a virtual plane formed by assuming that the outer edge of the coil, when viewed from the winding axis direction of the coil, is extended to both sides in the winding axis direction of the coil, and is located inside a columnar space sandwiched between two virtual planes that are in contact with both ends of the magnetic member in the winding axis direction of the coil and are perpendicular to the winding axis direction of the coil. The aforementioned protrusion is connected to the main body and is located outside the columnar space. Power generation element.

2. The aforementioned protrusion includes a first protrusion located outside the coil in a direction perpendicular to the winding axis of the coil, The power generation element according to claim 1.

3. A portion of the first protrusion is located closer to the center of the coil than the main body in the winding axis direction of the coil. The power generation element according to claim 2.

4. The first protrusion is located on the side of the coil opposite to the magnetic field source side. The power generation element according to claim 2.

5. The first protrusion is located on the magnetic field source side of the coil, The power generation element according to claim 2.

6. The aforementioned projection includes a second projection extending from the main body to the opposite side of the coil along the winding axis of the coil, The power generation element according to claim 1.

7. A magnetic component that produces the Great Barkhausen effect due to changes in the external magnetic field formed by a magnetic field source, A cylindrical ferrite member enclosing the aforementioned magnetic member, The system comprises a coil wound around the ferrite member, Power generation element.

8. The ferrite member comprises a cylindrical main body portion enclosing the magnetic member, The coil has flange-shaped first flange portion and second flange portion provided at both ends of the main body portion in the winding axis direction of the coil, The coil is located between the first flange and the second flange. The power generation element according to claim 7.

9. The ferrite member is a resin molded body containing at least one of soft magnetic powder and hard magnetic powder, and a resin. The power generation element according to claim 1.

10. A magnetic component that produces the Great Barkhausen effect due to changes in the external magnetic field formed by a magnetic field source, The coil wound around the magnetic member, The magnetic member comprises a ferrite member provided at the end of the magnetic member so as to be aligned with the coil along the winding axis of the coil, The ferrite member is a resin molded body containing at least one of soft magnetic powder and hard magnetic powder, and a resin. Power generation element.

11. The saturation magnetic flux density of the ferrite member is greater than that of the magnetic member. The power generation element according to claim 1.

12. The maximum residual magnetic flux density of the ferrite member is greater than the maximum residual magnetic flux density of the magnetic member. The power generation element according to claim 1.

13. A magnetic component that produces the Great Barkhausen effect due to changes in the external magnetic field formed by a magnetic field source, The magnetic member comprises a coil wound around the magnetic member, In the winding axis direction of the coil, the outer diameter of the end of the coil is smaller than the outer diameter of the central part of the coil. Power generation element.

14. In the winding axis direction of the coil, the number of turns per unit length at the ends of the coil is less than the number of turns per unit length in the central part of the coil. The power generation element according to claim 13.

15. A magnetic component that produces the Great Barkhausen effect due to changes in the external magnetic field formed by a magnetic field source, The first coil wound around the magnetic member, The first coil is positioned opposite to the magnetic field source side of the first coil, and a second coil is wound along an axis parallel to the winding axis of the first coil. Power generation element.

16. A plate-shaped magnetic member that produces the Great Barkhausen effect due to changes in the external magnetic field formed by a magnetic field source, The magnetic member comprises a coil wound around the magnetic member, The magnetic member has a plurality of first magnetic-sensitive layers and a plurality of second magnetic-sensitive layers that are harder magnetic than the plurality of first magnetic-sensitive layers. The plurality of first magnetic-sensitive layers and the plurality of second magnetic-sensitive layers are stacked alternately along a direction intersecting the winding axis direction of the coil. The total thickness of the plurality of first magnetic-sensitive layers is greater than the total thickness of the plurality of second magnetic-sensitive layers. Power generation element.

17. When viewed from the stacking direction, the shape of the magnetic member is elongated. The power generation element according to claim 16.

18. When viewed from the stacking direction, the shape of the magnetic member is elliptical. The power generation element according to claim 16.

19. A method for manufacturing a magnetic member used in a power generation element that produces the Great Barkhausen effect, The process of preparing a cylindrical magnetic material, The process includes injecting a magnetic material having different magnetic properties from the magnetic material into the interior of the magnetic material. A method for manufacturing magnetic materials.

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