Power generating element, magnetic sensor, and encoder

Abstract

Provided is a power generation element or the like which can easily apply a magnetic field to a magnet appropriately and is easy to manufacture. The power generation element (32) is provided with: a magnet (40) that generates a large Barkhausen effect; a coil (42) wound around the magnet (40); a first soft magnet (44) that is positioned further to the outside than the coil (42) in the winding axis direction in which the winding axis (B) of the coil (42) extends, and that is positioned further to the outside than the magnet (40) in the radial direction centered on the winding axis (B); and a filling member (48) including a second soft magnet and filled between the magnet (40) and the first soft magnet (44).

Description

Technical Field

[0001] The present disclosure relates to a power generating element, a magnetic sensor, and an encoder, and in particular to a power generating element, a magnetic sensor, and an encoder that utilize a large Barkhausen effect. Background Art

[0002] Conventionally, power generation elements utilizing the large Barkhausen effect are known, and for example, Patent Document 1 discloses a power generation element including a magnet that generates the large Barkhausen effect, a power generation coil wound around the magnet, and a soft magnetic body formed to press the magnet.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2021 / 200361 Summary of the invention

[0006] However, in the power generation element of patent document 1, there is a problem that it is difficult to properly apply a magnetic field to the magnet due to the gap between the magnet and the soft magnetic body. In addition, if the soft magnetic body and the magnet are to be brought into close contact in order to eliminate the gap between the magnet and the soft magnetic body, high-precision components and another process are required, which makes it difficult to manufacture the power generation element.

[0007] The present disclosure has been made to solve such a problem, and an object of the present disclosure is to provide a power generation element, a magnetic sensor, and an encoder that can easily apply a magnetic field to a magnet and can be easily manufactured.

[0008] One method of the present invention involves a power generation element comprising: a magnet that produces a large Barkhausen effect; a coil that is wound around the magnet; a first soft magnetic body that is located further outward than the coil in the winding axis direction along which the winding axis of the coil extends and is located on the outside of the magnet in the diameter direction centered on the winding axis; and a filling member that includes a second soft magnetic body and is filled between the magnet and the first soft magnetic body.

[0009] A magnetic sensor according to another aspect of the present disclosure includes: the above-mentioned power generating element; and a detection element that is driven based on electric power generated by the power generating element and detects magnetism.

[0010] An encoder according to another aspect of the present disclosure includes: a rotating magnet; and the above-mentioned power generating element, and generates power by a change in a magnetic field caused by the rotation of the magnet.

[0011] According to the present disclosure, it is possible to provide a power generation element, a magnetic sensor, and an encoder that can easily apply a magnetic field to a magnet and can be easily manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A It is a diagram showing a motor including an encoder according to the first embodiment.

[0013] Figure 1B It is a diagram showing the connection between the motor and the load according to the first embodiment.

[0014] Figure 2A It is a diagram showing a substrate included in the encoder according to the first embodiment.

[0015] Figure 2B It is a diagram showing a rotating plate included in the encoder according to the first embodiment.

[0016] Figure 3 yes Figure 2A A cross-sectional view of a power generating element taken along line III-III.

[0017] Figure 4 yes Figure 2A A cross-sectional view of a power generating element taken along line IV-IV.

[0018] Figure 5A This is a plan view of a power generating element used in simulations and the like, as viewed from the direction of the rotation axis.

[0019] Figure 5B It is shown Figure 5A A diagram showing a VB-VB cross section of the power generating element shown.

[0020] Figure 6 It is shown that by using Figure 5A as well as Figure 5B Graph of magnetic flux density obtained by simulation of the power generating element shown.

[0021] Fig. 7A This is a graph showing the amount of power generation obtained by measurement using a power generation element of a comparative example.

[0022] Figure 7B It is shown that by using Figure 5A A graph showing the amount of power generated by measuring the power generation element.

[0023] Fig. 8A This is a graph showing the standard deviation of the amount of electric power generated by measurement using the electric power generating element of the comparative example.

[0024] Figure 8B It is shown that by using Figure 5A A graph showing the standard deviation of power generation obtained by measuring the power generation elements.

[0025] Fig. 9 It is a cross-sectional view showing a power generating element of an encoder according to a second embodiment. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present disclosure. In addition, the embodiments described below all illustrate a specific example of the present disclosure. Therefore, the numerical values, constituent elements, the configuration positions and connection methods of the constituent elements, and the examples of the processes and the order of the processes shown in the following embodiments are not intended to limit the present disclosure. Therefore, the constituent elements that are not recorded in the independent claims among the constituent elements in the following embodiments are described as arbitrary constituent elements.

[0027] In addition, each figure is a schematic diagram and does not necessarily illustrate the figure strictly. In addition, in each figure, the same reference numerals are attached to substantially the same structure, and repeated descriptions are omitted or simplified.

[0028] (First embodiment)

[0029] Figure 1A It is a diagram showing a motor 1 including an encoder 20 according to the first embodiment. Figure 1A The diameter direction (in the direction of the rotation axis A of the rotating shaft 16 of the motor 1) is the center Figure 2A as well as Figure 2B In the figure, the direction indicated by the arrow X is observed. Figure 1A In FIG. 1 , the housing 18 and the magnet 26 are shown in cross section. Figure 1A In, omitted Figure 2A The diagrams of the power generating element 34 and the control circuit 30 are shown. Figure 1B 3 is a diagram showing the connection between the motor 1 and the load 300 . Figure 2A It is shown Figure 1A FIG. 24 is a diagram of a substrate 24 of an encoder 20. In addition, Figure 2B It is shown Figure 1A FIG. 2 is a diagram of a rotating plate 22 of an encoder 20 . Figure 2A as well as Figure 2B The direction extending from the rotation axis A of the rotation shaft 16, that is, the rotation axis direction (in Figure 1A The figure is observed in the direction indicated by arrow Y).

[0030] like Figure 1A As shown, the motor 1 includes a main body 10 , a rotor 12 , a stator 14 , a rotating shaft 16 , a housing 18 , and an encoder 20 .

[0031] The rotor 12 and the stator 14 are accommodated in the main body 10 . The rotor 12 rotates relative to the stator 14 .

[0032] The rotating shaft 16 is fixed to the rotor 12 and rotates around the rotating axis A together with the rotor 12. That is, the rotating axis A is the rotation center of the rotating shaft 16 and the rotor 12. The rotating shaft 16 extends in the direction of the rotating axis A and is in the shape of a rod such as a cylinder. The axis of the rotating shaft 16 and the rotating axis A coincide with each other. For example, when electric power is supplied to the motor 1, the rotating shaft 16 rotates together with the rotor 12 with the rotating axis A as the rotation center based on the electric power. The rotation direction of the rotating shaft 16 (in Figure 2A as well as Figure 2B The direction indicated by the arrow Z in FIG. 1 is consistent with the circumferential direction centered on the rotation axis A. An encoder 20 is provided at one end of the rotation shaft 16 in the direction of the rotation axis. For example, Figure 1B As shown, a load 300 that is driven to rotate by the rotation of the rotating shaft 16 is installed at the other end of the rotating shaft 16 in the direction of the rotating axis. For example, the rotating shaft 16 is formed by a magnetic metal such as iron. In addition, for example, the rotating shaft 16 can also be formed by a non-magnetic metal. In addition, as long as it is a device driven by the motor 1, the load 300 can be any, for example, it can be a wheel used in a moving body such as a car or a train, or it can be a blade of a fan.

[0033] The housing 18 is attached to the main body 10 so as to cover one end portion of the rotating shaft 16 in the rotation axis direction and the encoder 20. For example, the housing 18 is formed of a magnetic metal such as iron.

[0034] The encoder 20 detects the rotation of a rotating body. In the present embodiment, the rotating shaft 16 corresponds to the rotating body, and the encoder 20 detects the rotation of the rotating shaft 16. For example, the encoder 20 detects the rotation position of the rotating shaft 16, the rotation direction of the rotating shaft 16, and the number of revolutions of the rotating shaft 16. For example, the encoder 20 detects the rotation of the rotating shaft 16 by at least one of an absolute method and an incremental method. In the present embodiment, the encoder 20 is a battery-free encoder. As described above, in the present embodiment, the encoder 20 is disposed at one end of the rotating shaft 16 in the direction of the rotation axis. Figure 1A , Figure 2A as well as Figure 2B As shown, the encoder 20 has a rotating plate 22 , a base plate 24 , a magnet 26 , a magnetic sensor 28 , and a control circuit 30 .

[0035] The rotating plate 22 is a plate-shaped plate with the thickness direction being the direction of the rotation axis, and extends in a direction orthogonal to the direction of the rotation axis. The rotating plate 22 is circular when viewed from the direction of the rotation axis, and is a disc-shaped plate. In addition, for example, the rotating plate 22 may not be a disc-shaped plate, but may be a ring-shaped plate. The rotating plate 22 is mounted on one end of the rotating shaft 16 in the direction of the rotation axis. The axis of the rotating plate 22 and the rotation axis A are consistent with each other. The rotating plate 22 rotates together with the rotating shaft 16.

[0036] The substrate 24 is in the shape of a plate with the thickness direction being the direction of the rotation axis, and extends in a direction orthogonal to the direction of the rotation axis. The substrate 24 is circular when viewed from the direction of the rotation axis, and is in the shape of a circular plate. The substrate 24 is arranged with a gap between one end of the rotation shaft 16 and the rotation plate 22 in the direction of the rotation axis, and is opposed to the rotation plate 22. The axis of the substrate 24 and the rotation axis A coincide with each other. The substrate 24 is fixed so as not to rotate together with the rotation shaft 16.

[0037] The magnet 26 rotates. In the present embodiment, if the rotating shaft 16 rotates, the magnet 26 rotates together with the rotating shaft 16 and the rotating plate 22. The magnet 26 is annular and is arranged along the rotation direction of the rotating shaft 16. The magnet 26 is in the shape of a plate with the thickness direction being the direction of the rotation axis. The magnet 26 is arranged on the main surface of the rotating plate 22 on the opposite side of the substrate 24. The magnet 26 has an N pole and an S pole arranged side by side with the N pole in the rotation direction of the rotating shaft 16. Half of one side of the magnet 26 is magnetized as an N pole, and half of the other side of the magnet 26 is magnetized as an S pole. In addition, the magnet 26 only needs to be configured so as to enable the power generation element 32 and the power generation element 34 to generate electricity by rotating together with the rotating shaft 16. Specifically, for example, the magnet 26 may also be as described later. Figure 5A as well as Figure 5B As shown in the figure, the magnets 106 and 108 are magnetized so that the N poles and the S poles are arranged in the radial direction around the rotation axis A.

[0038] The magnetic sensor 28 is a sensor for detecting magnetism. The magnetic sensor 28 has a plurality of power generation elements 32 and 34 and a plurality of detection elements 36 and 38. In addition, for example, the magnetic sensor 28 may have one power generation element instead of a plurality of power generation elements. In addition, for example, the magnetic sensor 28 may have one detection element instead of a plurality of detection elements.

[0039] Each of the plurality of power generating elements 32 and 34 generates power by a change in magnetic field caused by the rotation of the magnet 26. In the present embodiment, each of the plurality of power generating elements 32 and 34 generates power by a change in magnetic field caused by the rotation of the magnet 26 and the rotating shaft 16.

[0040] For example, when the magnet 26 rotates from a state where one end of a magnet 40 (described later) of the power generation element 32 faces the N pole of the magnet 26 and the other end of the magnet 40 of the power generation element 32 faces the S pole of the magnet 26, and thus becomes a state where one end of the magnet 40 of the power generation element 32 faces the S pole of the magnet 26 and the other end of the magnet 40 of the power generation element 32 is close to the N pole of the magnet 26 to a certain extent, the magnetization direction of the magnet 40 is reversed, and the power generation element 32 generates electricity. The same is true for the power generation element 34.

[0041] Furthermore, for example, when the magnet 26 rotates from a state where one end of the magnet 40 of the power generating element 32 faces the S pole of the magnet 26 and the other end of the magnet 40 of the power generating element 32 faces the N pole of the magnet 26, and the power generating element 32 is brought into a state where one end of the magnet 40 of the power generating element 32 faces the N pole of the magnet 26 and the other end of the magnet 40 of the power generating element 32 is brought into a state where ... S pole of the magnet 26 is brought into a state where the power generating element 32 generates electricity. The same is true for the power generating element 34.

[0042] The plurality of power generation elements 32 and 34 extend in the tangential direction of the rotation direction of the rotation shaft 16. Specifically, the plurality of power generation elements 32 and 34 are arranged so that the magnet 40 extends in the tangential direction of the rotation direction of the rotation shaft 16. In addition, the plurality of power generation elements 32 and 34 only need to be arranged so as to generate power by the change of the magnetic field caused by the rotation of the magnet 26.

[0043] The plurality of power generation elements 32 and 34 are arranged on the main surface of the substrate 24 facing the direction opposite to the rotation axis 16 (facing the direction opposite to the rotation plate 22). Alternatively, the plurality of power generation elements 32 and 34 may be arranged on the main surface of the substrate 24 facing the rotation axis 16 (facing the rotation plate 22). The plurality of power generation elements 32 and 34 are arranged side by side in the rotation direction of the rotation axis 16.

[0044] The details of the plurality of power generating elements 32 and 34 will be described later.

[0045] The plurality of detection elements 36 and 38 are driven based on the power generated by the power generating element 32 to detect magnetism. In the present embodiment, the plurality of detection elements 36 and 38 are driven based on the power generated by the power generating element 32 to detect magnetism of the magnet 26.

[0046] In addition, the plurality of detection elements 36 and 38 are driven based on the power generated by the power generating element 34 to detect magnetism. In this embodiment, the plurality of detection elements 36 and 38 are driven based on the power generated by the power generating element 34 to detect magnetism of the magnet 26.

[0047] The plurality of detection elements 36 and 38 are arranged on the main surface of the substrate 24 facing the rotation axis 16 (facing the rotation plate 22). Alternatively, the plurality of detection elements 36 and 38 may be arranged on the main surface of the substrate 24 facing the direction opposite to the rotation axis 16 (facing the direction opposite to the rotation plate 22). The plurality of detection elements 36 and 38 are arranged in a row in the rotation direction of the rotation axis 16.

[0048] The control circuit 30 is arranged on the main surface of the substrate 24 facing the rotating shaft 16 (facing the rotating plate 22), and is electrically connected to the plurality of power generation elements 32, 34, etc. For example, the control circuit 30 determines the rotation position of the rotating shaft 16, etc., according to which power generation element among the plurality of power generation elements 32, 34 has generated power. In addition, for example, the control circuit 30 determines the rotation position of the rotating shaft 16, etc. based on the detection results of the plurality of detection elements 36, 38. In addition, for example, the control circuit 30 determines the rotation position of the rotating shaft 16, etc., based on which power generation element among the plurality of power generation elements 32, 34 has generated power and the detection results of the plurality of detection elements 36, 38. In this way, the encoder 20 detects the rotation of the rotating shaft 16.

[0049] Figure 3 yes Figure 2A sectional view of the power generating element 32 taken along line III-III. Figure 4 yes Figure 2A sectional view of the power generating element 32 taken along line IV-IV.

[0050] like Figure 3 as well as Figure 4 As shown, the power generating element 32 includes a magnet 40 , a coil 42 , a first soft magnetic body 44 , a case 46 , and a filling member 48 .

[0051] The magnet 40 is a magnet that generates a large Barkhausen effect. The magnet is formed of a magnetic material. For example, the magnet 40 is a composite magnetic wire such as a Wiegand wire. The Wiegand wire is a magnet whose magnetization direction is consistent in one direction along the length direction (extension direction) of the Wiegand wire if a magnetic field of a given value or more is applied along the length direction (extension direction) of the Wiegand wire.

[0052] The magnet 40 is wound with a coil 42, and the magnet 40 extends in the direction of the winding axis B of the coil 42, that is, the winding axis direction (in the Figure 3 In the present embodiment, the axis of the magnet 40 is consistent with the winding axis B.

[0053] The magnet 40 protrudes outward from the coil 42 in the winding axis direction. Specifically, the magnet 40 protrudes in one direction from the coil 42 in the winding axis direction, and further protrudes in the other direction from the coil 42.

[0054] The coil 42 is wound around the magnet 40. The coil 42 is wound around the magnet 40 so that when a large Barkhausen effect is generated by the magnet 40, the coil 42 generates electricity. In the present embodiment, the coil 42 is wound around the magnet 40 so that the winding axis B of the coil 42 is consistent with the extension direction of the magnet 40. If the direction of the magnetic flux flowing along the extension direction (length direction) of the magnet 40 changes, the magnetization direction of the magnet 40 flips abruptly, and a power generation pulse is generated in the coil 42. In this way, the power generation element 32 generates electricity.

[0055] The first soft magnetic material 44 is located outside the coil 42 in the winding axis direction along which the winding axis B of the coil 42 extends, and is centered in the radial direction (see Figure 4 The first soft magnetic body 44 is formed of a soft magnetic material. For example, the first soft magnetic body 44 is a ferrite bead.

[0056] In the present embodiment, the first soft magnetic body 44 is located closer to one direction than the coil 42 in the winding axis direction, and in the one direction, is located outside the magnet 40 in the diameter direction centered on the winding axis B. In addition, in the present embodiment, the first soft magnetic body 44 is located closer to another direction than the coil 42 in the winding axis direction, and in the other direction, is located outside the magnet 40 in the diameter direction centered on the winding axis B. That is, in the present embodiment, the power generation element 32 has two first soft magnetic bodies 44. The two first soft magnetic bodies 44 are symmetrically arranged with the coil 42 sandwiched therebetween.

[0057] The first soft magnetic material 44 is arranged along the circumferential direction (refer to Figure 4 The first soft magnetic body 44 is annular and cylindrical with the winding axis direction as the axial direction. In addition, the first soft magnetic body 44 may not be cylindrical, but may be, for example, a polygonal cylindrical shape.

[0058] The inner surface 50 of the first soft magnetic body 44 in the diameter direction centered on the winding axis B is opposite to the magnet 40 in the diameter direction centered on the winding axis B. In the present embodiment, the inner surface 50 of the first soft magnetic body 44 is parallel to the winding axis direction and is annular along the circumferential direction centered on the winding axis B. The inner surface 50 of the first soft magnetic body 44 does not contact the magnet 40.

[0059] The housing 46 accommodates and supports the magnet 40 , the coil 42 , and the first soft magnetic body 44 .

[0060] The filling member 48 is filled between the magnet 40 and the first soft magnetic body 44. The filling member 48 is filled between the magnet 40 and the first soft magnetic body 44 in the diameter direction centered on the winding axis B. In the present embodiment, the filling member 48 is filled between the magnet 40 and the inner surface 50 of the first soft magnetic body 44. In the present embodiment, the filling member 48 is filled so that the gap between the magnet 40 and the inner surface 50 of the first soft magnetic body 44 is completely buried by the filling member 48 when viewed from the winding axis direction.

[0061] In the present embodiment, the filling member 48 is not filled between the end of the inner surface 50 of the first soft magnetic body 44 on the coil 42 side and the magnet 40 , but the filling member 48 may be filled therebetween.

[0062] The filling member 48 includes a second soft magnetic material. For example, the filling member 48 includes a powdered second soft magnetic material. For example, the second soft magnetic material is powdered ferrite or the like.

[0063] The filling member 48 is an adhesive, and the magnet 40 is fixed to the first soft magnetic body 44 via the filling member 48. For example, the filling member 48 is an adhesive that changes from a liquid state to a solid state.

[0064] The second soft magnetic material has a higher magnetic permeability than the first soft magnetic material 44. For example, the magnetic permeability of the second soft magnetic material and the amount of the second soft magnetic material contained in the filling member 48 are determined so that the magnetic permeability of the filling member 48 is higher than the magnetic permeability of the first soft magnetic material 44.

[0065] The power generating element 34 has the same structure as that of the power generating element 32 , and thus a detailed description of the power generating element 34 will be omitted.

[0066] Figure 5A as well as Figure 5B 1 is a diagram showing a power generating element 100 used in simulations and the like. Figure 5A This is a diagram viewed from the direction of the rotation axis. Figure 5B yes Figure 5A Cross-sectional view at the VB-VB line in FIG.

[0067] like Figure 5A as well as Figure 5B As shown, the power generating element 100 includes a magnet 40, a coil 42, a first soft magnetic body 44, and a filling member 48. The power generating element 100 differs from the power generating element 32 mainly in that the filling member 48 is filled to fill the gap between the magnet 40 and the first soft magnetic body 44.

[0068] Here, the diameter of the magnet 40 is 0.35 mm, and the inner diameter of the first soft magnetic body 44 is 0.7 mm.

[0069] For example, when the state changes from one end of magnet 40 being opposite to the N pole of magnet 106 and the other end of magnet 40 being opposite to the S pole of magnet 108 to one end of magnet 40 being opposite to the S pole of magnet 108 and the other end of magnet 40 being close to the N pole of magnet 106 to some extent, the generating element 100 generates electricity.

[0070] In addition, for example, when the state changes from one end of the magnet 40 being opposite to the S pole of the magnet 108 and the other end of the magnet 40 being opposite to the N pole of the magnet 106 to a state where one end of the magnet 40 is opposite to the N pole of the magnet 106 and the other end of the magnet 40 is close to the S pole of the magnet 108 to a certain extent, the generating element 100 generates electricity.

[0071] Figure 6 It is shown that by using Figure 5A as well as Figure 5B FIG. 1 is a graph showing the magnetic flux density obtained by simulation of the power generating element 100 shown in FIG. Figure 6 In the graph of , the example (solid line) shows the simulation result using the power generation element 100 , and the comparative example (one-dot chain line) shows the simulation result using the power generation element in which the filling member 48 is removed from the power generation element 100 .

[0072] like Figure 6 As shown, the magnetic flux density of the power generation element 100 of the embodiment is more uniform and close between the position of about 4.5 mm from the center (0 mm) of the magnet 40 and the position of about -4.5 mm from the center (0 mm) of the magnet 40, compared with the power generation element of the comparative example. Thus, it can be seen that the magnetic flux density of the power generation element 100 of the embodiment that contributes to the power generation by the coil 42 is higher than that of the power generation element of the comparative example.

[0073] Fig. 7A It is a graph showing the amount of power generation obtained by measurement using the power generation element according to the comparative example. Figure 7B It is shown that by using Figure 5A as well as Figure 5B The graph of the amount of power generated by measuring the power generating element 100 according to the embodiment shown in FIG. Fig. 7A as well as Figure 7B In each case, the horizontal axis represents Figure 5B The magnet-to-magnet distance (unit: mm) is shown, and the vertical axis represents the power generation (unit: nJ). Fig. 7A as well as Figure 7B The average value (single-point dashed line) in the graph is the average value of the power generation of 2500 power generation pulses. Fig. 7A as well as Figure 7BThe minimum value (solid line) in the graph is the minimum value of the power generation amount of 2500 power generation pulses.

[0074] like Fig. 7A As shown, in the power generating element according to the comparative example, if the distance between the magnet 40 and the magnet 106 (or the magnet 108) (magnet-magnet distance, refer to Figure 5B ) changes, the average and minimum power generation of 2500 power generation pulses will change significantly.

[0075] like Figure 7B As shown, it can be seen that in the power generation element 100 involved in the embodiment, if the distance between the magnet 40 and the magnet 106 (or the magnet 108) changes, although the average value and the minimum value of the power generation of 2500 power generation pulses change, their changes are smaller than those of the power generation element involved in the comparative example.

[0076] In this way, with respect to the power generating element 100 involved in the embodiment, even if the distance between the magnet 40 and the magnet 106 (magnet 108) changes, the average value and the minimum value of the power generation amount of the power generation pulse are less likely to change compared to the power generating element involved in the comparative example, and the magnetic field can be appropriately applied to the magnet 40 compared to the power generating element involved in the comparative example.

[0077] Fig. 8A It is a graph showing the standard deviation of the amount of electric power generated by measurement using the electric power generating element according to the comparative example. Figure 8B It is shown that by using Figure 5A as well as Figure 5B The graph of the standard deviation of the power generation amount obtained by measuring the power generation element 100 according to the embodiment shown in FIG. Fig. 8A as well as Figure 8B In each case, the horizontal axis represents Figure 5B The magnet-to-magnet distance (unit: mm) is shown, and the vertical axis represents the standard deviation of power generation (unit: nJ). Fig. 8A as well as Figure 8B The average value (single-point dashed line) in the graph is the average value of the standard deviation of the power generation of 2500 power generation pulses. Fig. 8A as well as Figure 8B The maximum value (solid line) in the graph is the maximum value of the standard deviation of the power generation of 2500 power generation pulses.

[0078] like Fig. 8A As shown, in the power generating element according to the comparative example, when the distance between the magnet 40 and the magnet 106 (or the magnet 108 ) changes, the average value of the standard deviation of the power generation amount of 2500 power generation pulses and the maximum value of the standard deviation change significantly.

[0079] like Figure 8BAs shown, it can be seen that in the power generating element 100 involved in the embodiment, if the distance between the magnet 40 and the magnet 106 (or the magnet 108) changes, although the average value of the standard deviation of the power generation of 2500 power generation pulses and the maximum value of the standard deviation change, their changes are smaller than those of the power generating element involved in the comparison example.

[0080] In this way, with respect to the power generating element 100 involved in the embodiment, even if the distance between the magnet 40 and the magnet 106 (or the magnet 108) changes, the average value of the standard deviation of the power generation of the power generation pulse and the maximum value of the standard deviation are less likely to change compared to the power generating element involved in the comparative example, and a magnetic field can be appropriately applied to the magnet 40 compared to the power generating element involved in the comparative example.

[0081] The power generating element 32 involved in this embodiment comprises: a magnet 40 that generates a large Barkhausen effect; a coil 42 wound on the magnet 40; a first soft magnetic body 44, which is located at a position further outward than the coil 42 in the winding axis direction extending from the winding axis B of the coil 42, and is located on the outside of the magnet 40 in the diameter direction centered on the winding axis B; and a filling member 48, including a second soft magnetic body, which is filled between the magnet 40 and the first soft magnetic body 44.

[0082] According to this, since the filling member 48 including the second soft magnetic body is filled between the magnet 40 and the first soft magnetic body 44, it is possible to suppress the generation of a gap between the magnet 40 and the first soft magnetic body 44, and it is easy to appropriately apply a magnetic field to the magnet 40. In addition, it is not necessary to make the first soft magnetic body 44 and the magnet 40 close to each other so that no gap is generated between the magnet 40 and the first soft magnetic body 44, so it is easy to manufacture the power generation element 32. In this way, it is easy to appropriately apply a magnetic field to the magnet 40, and it is easy to manufacture the power generation element 32.

[0083] In the power generating element 32 according to the present embodiment, the filling member 48 is an adhesive, and the magnet 40 is fixed to the first soft magnetic body 44 via the filling member 48 .

[0084] According to this, the magnet 40 can be fixed to the first soft magnetic body 44 via the filling member 48 , so that the power generating element 32 can be manufactured more easily.

[0085] Furthermore, in the power generating element 32 according to the present embodiment, the magnetic permeability of the second soft magnetic body is greater than the magnetic permeability of the first soft magnetic body 44 .

[0086] This can prevent the magnetic permeability of the filling member 48 from becoming lower than the magnetic permeability of the first soft magnetic body 44 , and thus makes it easier to appropriately apply a magnetic field to the magnet 40 .

[0087] The magnetic sensor 28 according to the present embodiment includes the above-mentioned power generating element 32 and a detection element 36 , which is driven based on the electric power generated by the power generating element 32 and detects magnetism.

[0088] This achieves the same operational effects as those of the above-described power generating element 32 .

[0089] The encoder 20 according to the present embodiment includes the rotating magnet 26 and the above-mentioned power generating element 32 , and generates power by a change in the magnetic field caused by the rotation of the magnet 26 .

[0090] This achieves the same operational effects as those of the above-described power generating element 32 .

[0091] (Second embodiment)

[0092] Fig. 9 It is a cross-sectional view showing a power generating element 200 of an encoder according to a second embodiment.

[0093] The encoder according to the second embodiment is different from the encoder 20 mainly in that a power generating element 200 is provided instead of the power generating element 32 , and a power generating element 200 is provided instead of the power generating element 34 .

[0094] like Fig. 9 As shown, the power generating element 200 is different from the power generating element 32 mainly in that it has a first soft magnetic body 202 which is different from the first soft magnetic body 44. The first soft magnetic body 202 has two magnetic pieces 204 and 206.

[0095] The first soft magnetic body 202 presses the magnet 40 in the diameter direction centered on the winding axis B. In the present embodiment, the magnet piece 204 presses the magnet 40 from one side in the diameter direction centered on the winding axis B, and the magnet piece 206 presses the magnet 40 from the other side in the diameter direction. For example, the magnet piece 204 and the magnet piece 206 apply force in a direction of approaching each other by tightening with screws or the like, thereby pressing the magnet 40.

[0096] The first soft magnetic body 202 is in contact with the magnet 40. The inner surface 208 of the magnet piece 204 in the diameter direction with the winding axis B as the center is opposite to the magnet 40 in the diameter direction, and is recessed toward the outside of the diameter direction when viewed from the winding axis direction. In the present embodiment, the inner surface 208 of the magnet piece 204 is recessed into a roughly L-shaped shape. In addition, for example, the inner surface 208 of the magnet piece 204 may also be recessed into an elliptical arc shape. A portion of the inner surface 208 of the magnet piece 204 is in contact with the magnet 40. In addition, the inner surface 210 of the magnet piece 206 in the diameter direction with the winding axis B as the center is opposite to the magnet 40 in the diameter direction, and is recessed toward the outside of the diameter direction when viewed from the winding axis direction. In the present embodiment, the inner surface 210 of the magnet piece 206 is recessed into a roughly L-shaped shape. In addition, for example, the inner surface 210 of the magnet piece 206 may also be recessed into an elliptical arc shape. A portion of the inner surface 210 of the magnet piece 206 is in contact with the magnet 40 .

[0097] Filling member 48 is filled so as to fill gaps between inner surface 208 of magnet piece 204 and magnet 40 and between inner surface 210 of magnet piece 206 and magnet 40 when viewed from the winding axis direction.

[0098] In the power generating element 200 according to the present embodiment, the first soft magnetic body 202 presses the magnet 40 in the radial direction about the winding axis B.

[0099] This can suppress the generation of a gap between the magnet 40 and the first soft magnetic body 44 , and thus makes it easier to appropriately apply a magnetic field to the magnet 40 .

[0100] Furthermore, in the power generating element 200 according to the present embodiment, the first soft magnetic body 202 is in contact with the magnet 40 .

[0101] This can suppress the generation of a gap between the magnet 40 and the first soft magnetic body 44 , and thus makes it easier to appropriately apply a magnetic field to the magnet 40 .

[0102] (Other implementations, etc.)

[0103] As described above, the embodiments are described as examples of the technology disclosed in this application. However, the technology based on the present disclosure is not limited to these, and can be applied to embodiments or modified examples that are appropriately changed, replaced, added, omitted, etc. as long as they do not depart from the gist of the present disclosure.

[0104] In the above-mentioned embodiment, the filling member 48 is an adhesive and the magnet 40 is fixed to the first soft magnetic body 44 via the filling member 48, but it is not limited to this. For example, the filling member 48 may not be an adhesive, and the magnet 40 may be fixed to the box body by other adhesives, etc. The same is true for the first soft magnetic body 202.

[0105] In the above embodiment, the magnetic permeability of the second soft magnetic body is greater than the magnetic permeability of the first soft magnetic body 44, but the present invention is not limited thereto. For example, the magnetic permeability of the second soft magnetic body may be less than the magnetic permeability of the first soft magnetic body 44. The same is true for the first soft magnetic body 202.

[0106] Industrial Applicability

[0107] The power generating element, magnetic sensor, and encoder according to the present disclosure can be used in a power generating element or the like that utilizes the large Barkhausen effect.

[0108] Description of Reference Numerals

[0109] 1 Motor

[0110] 10 Main Body

[0111] 12 Rotor

[0112] 14 Stator

[0113] 16 Rotation axis

[0114] 18 Housing

[0115] 20 Encoder

[0116] 22 Rotating Plate

[0117] 24 substrate

[0118] 26, 106, 108 magnets

[0119] 28 Magnetic Sensor

[0120] 30 Control circuit

[0121] 32, 34, 100, 200 Power generation elements

[0122] 36, 38 Detection element

[0123] 40 Magnet

[0124] 42 Coil

[0125] 44,202 1st soft magnet

[0126] 46 Cabinet

[0127] 48 Filling components

[0128] 50, 208, 210 inner surface

[0129] 204, 206 magnet pieces.

Claims

1. A power generation element comprising: magnets, producing a large Barkhausen effect; a coil wound around the magnet; a first soft magnetic body located outside the coil in a winding axis direction along which the winding axis of the coil extends and outside the magnet in a diameter direction centered on the winding axis; and The filling member includes a second soft magnetic body and is filled between the magnetic body and the first soft magnetic body.

2. The power generating element according to claim 1, wherein The filling member is an adhesive, The magnet is fixed to the first soft magnetic body via the filling member.

3. The power generating element according to claim 1, wherein The magnetic permeability of the second soft magnetic body is greater than the magnetic permeability of the first soft magnetic body.

4. The power generating element according to claim 1, wherein The first soft magnetic body presses the magnet in the radial direction.

5. The power generating element according to claim 1, wherein The first soft magnetic body is in contact with the magnetic body.

6. A magnetic sensor comprising: The power generating element according to any one of claims 1 to 5; and The detection element is driven based on the electric power generated by the power generation element, and detects magnetism.

7. An encoder comprising: Rotating magnets; and The power generating element according to any one of claims 1 to 5 generates power by a change in the magnetic field caused by the rotation of the magnet.

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