Self-powered sensor

Abstract

This self powered sensor comprises: a first soft magnetic component; a second soft magnetic component; a magnetic wire capable of exhibiting a large Barkhausen effect; a coil; a first external electrode terminal attached to the first soft magnetic component; and a second external electrode terminal attached to the second soft magnetic component. A first coil terminal wire and a second coil terminal wire are respectively joined to the first external electrode terminal and the second external electrode terminal by welding.

Description

Power generation sensor

[0001] This disclosure relates to a power generation sensor. This application claims priority under Japanese application No. 2024-177721, filed on 10 October 2024, and incorporates all the provisions contained herein.

[0002] Patent Document 1 (Japanese Patent Application Publication No. 2023-119403) discloses a power generation sensor comprising a magnetic wire, a coil, a magnetic flux conducting piece, and an external electrode terminal. The coil includes a coil terminal wire. A projection is provided on the external electrode terminal. The coil terminal wire is electrically connected to the external electrode terminal by wrapping it around the projection on the external electrode terminal.

[0003] Japanese Patent Publication No. 2023-119403

[0004] The power generation sensor of this disclosure comprises a first soft magnetic component, a second soft magnetic component, a magnetic wire capable of exhibiting the Great Barkhausen effect, a coil, a first external electrode terminal, and a second external electrode terminal. The first soft magnetic component includes a first soft magnetic body. The second soft magnetic component includes a second soft magnetic body. The coil includes a coil body, a first coil terminal wire connected to the coil body, and a second coil terminal wire connected to the coil body. The first external electrode terminal is mounted on the first soft magnetic body. The second external electrode terminal is mounted on the second soft magnetic body. At least a portion of the magnetic wire is arranged inside the coil body. The coil body is arranged between the first soft magnetic body and the second soft magnetic body. The first coil terminal wire is joined to the first external electrode terminal by welding. The second coil terminal wire is joined to the second external electrode terminal by welding.

[0005] Figure 1 is a schematic perspective view of the power generation sensor of Embodiment 1. Figure 2 is a schematic side view of the power generation sensor of Embodiment 1. Figure 3 is a schematic top view of the power generation sensor of Embodiment 1. Figure 4 is a schematic exploded perspective view of the power generation sensor of Embodiment 1. Figure 5 is a schematic partially enlarged cross-sectional view of the coil body. Figure 6 is a schematic partially enlarged cross-sectional view of the self-fusing wire. Figure 7 is a photograph showing the first coil terminal wire and the first external electrode terminal joined to each other by resistance welding. Figure 8 is a schematic perspective view showing a first example of using the power generation sensor of Embodiment 1 as a rotation sensor. Figure 9 is a schematic perspective view showing a second example of using the power generation sensor of Embodiment 1 as a rotation sensor. Figure 10 is a schematic partially enlarged exploded perspective view of the power generation sensor of a first modified example of Embodiment 1. Figure 11 is a schematic partially enlarged exploded perspective view of the power generation sensor of a second modified example of Embodiment 1. Figure 12 is a schematic partially enlarged exploded perspective view of the power generation sensor of a third modified example of Embodiment 1. Figure 13 is a schematic partially enlarged exploded perspective view of the power generation sensor of a fourth modified example of Embodiment 1. Figure 14 is a schematic partially enlarged exploded perspective view of a fifth modified example of the power generation sensor of Embodiment 1. Figure 15 is a schematic plan view of a sixth modified example of the power generation sensor of Embodiment 1. Figure 16 is a schematic perspective view of the power generation sensor of Embodiment 2. Figure 17 is a schematic side view of the power generation sensor of Embodiment 2. Figure 18 is a schematic plan view of the power generation sensor of Embodiment 2. Figure 19 is a schematic perspective view of a modified example of the power generation sensor of Embodiment 2. Figure 20 is a schematic rear view of a modified example of the power generation sensor of Embodiment 2. Figure 21 is a schematic perspective view of the power generation sensor of Embodiment 3. Figure 22 is a schematic exploded perspective view of the power generation sensor of Embodiment 3. Figure 23 is a schematic exploded perspective view of the power generation sensor of Embodiment 3.

[0006] In the power generation sensor described in Patent Document 1, it is necessary to provide a projection on the external electrode terminal for wrapping the coil terminal wire. As a result, the size of the power generation sensor increases. Furthermore, because the coil terminal wire is wrapped around the projection on the external electrode terminal, the reliability of the electrical connection between the coil terminal wire and the external electrode terminal is low. This disclosure has been made in view of the above problems, and its purpose is to provide a power generation sensor that can be made smaller and whose electrical connection reliability between the coil terminal wire and the external electrode terminal can be improved.

[0007] The power generation sensor of this disclosure makes it possible to miniaturize the power generation sensor and improve the reliability of the electrical connection between the first coil terminal wire and the first external electrode terminal, as well as the reliability of the electrical connection between the second coil terminal wire and the second external electrode terminal.

[0008] [Description of Embodiments of the Disclosure] First, embodiments of the Disclosure will be listed and described.

[0009] (1) The power generation sensor according to the present disclosure comprises a first soft magnetic component, a second soft magnetic component, a magnetic wire capable of exhibiting the Great Barkhausen effect, a coil, a first external electrode terminal, and a second external electrode terminal. The first soft magnetic component includes a first soft magnetic body. The second soft magnetic component includes a second soft magnetic body. The coil includes a coil body, a first coil terminal wire connected to the coil body, and a second coil terminal wire connected to the coil body. The first external electrode terminal is mounted on the first soft magnetic body. The second external electrode terminal is mounted on the second soft magnetic body. At least a portion of the magnetic wire is arranged inside the coil body. The coil body is arranged between the first soft magnetic body and the second soft magnetic body. The first coil terminal wire is joined to the first external electrode terminal by welding. The second coil terminal wire is joined to the second external electrode terminal by welding.

[0010] The first coil terminal wire and the second coil terminal wire are joined to the first external electrode terminal and the second external electrode terminal, respectively, by welding. As a result, the power generation sensor can be miniaturized, and the reliability of the electrical connection between the first coil terminal wire and the first external electrode terminal, and the reliability of the electrical connection between the second coil terminal wire and the second external electrode terminal can be improved.

[0011] (2) In the power generation sensor described in (1) above, the first coil terminal wire and the second coil terminal wire each have a load of 200 N / mm ２ It possesses the above tensile strength.

[0012] Therefore, even if vibration or mechanical shock is applied to the first coil terminal wire and the second coil terminal wire, disconnection of the first coil terminal wire and the second coil terminal wire can be prevented. The reliability of the electrical connection between the first coil terminal wire and the first external electrode terminal, and the reliability of the electrical connection between the second coil terminal wire and the second external electrode terminal can be improved.

[0013] (3) In the power generation sensor described in (2) above, the first coil terminal wire and the second coil terminal wire are each single wires.

[0014] The first coil terminal wire and the second coil terminal wire each have a load capacity of 200 N / mm ２ Because of the above tensile strength, even if the first and second coil terminal wires are solid wires rather than stranded wires, the first and second coil terminal wires have higher resistance to vibration and mechanical shock. The reliability of the electrical connection between the first coil terminal wire and the first external electrode terminal, and the reliability of the electrical connection between the second coil terminal wire and the second external electrode terminal can be improved. The cost of the power generation sensor can be reduced.

[0015] (4) In the power generation sensor according to any of (1) to (3) above, the first external electrode terminal is a first lead frame having a first bonding plane. The first coil terminal wire is joined to the first bonding plane by welding. The second external electrode terminal is a second lead frame having a second bonding plane. The second coil terminal wire is joined to the second bonding plane by welding.

[0016] The first coil terminal wire and the second coil terminal wire are joined to the first joining plane and the second joining plane, respectively. This facilitates welding and improves welding reliability. The reliability of the electrical connection between the first coil terminal wire and the first external electrode terminal, and the reliability of the electrical connection between the second coil terminal wire and the second external electrode terminal can be improved. Furthermore, the welding process can be automated.

[0017] (5) In the power generation sensor according to any of (1) to (4) above, the first coil terminal wire is joined to the first external electrode terminal by resistance welding. The second coil terminal wire is joined to the second external electrode terminal by resistance welding.

[0018] The first coil terminal wire and the second coil terminal wire are joined to the first external electrode terminal and the second external electrode terminal, respectively, by resistance welding. As a result, the power generation sensor can be miniaturized, and the reliability of the electrical connection between the first coil terminal wire and the first external electrode terminal, and the reliability of the electrical connection between the second coil terminal wire and the second external electrode terminal can be improved.

[0019] (6) In the power generation sensor relating to any of (1) to (5) above, the coil body is formed of a self-fusing coil.

[0020] Therefore, the coil body can be placed around the magnetic wire without winding the coil wire around it. Since almost no stress is applied from the coil body to the magnetic wire, the magnetic wire can appropriately exhibit the Great Barkhausen effect in accordance with the magnetic flux from the magnetic field source. This improves the detection accuracy of the power generation sensor.

[0021] (7) In the power generation sensor according to any of (1) to (6) above, the coil body includes a coil wire wound around a magnetic wire. The coil wire has a strength of 200 N / mm ２ It possesses the above tensile strength.

[0022] The coil wire has a load capacity of 200 N / mm. ２ Because it possesses the above tensile strength, the coil wire can be wound with higher tension. Therefore, the inner diameter of the coil body can be reduced, bringing the coil wire closer to the magnetic wire. The electromagnetic coupling between the coil wire and the magnetic wire increases, improving the accuracy of the power generation sensor. Furthermore, the outer diameter of the coil body can be reduced, allowing for miniaturization of the power generation sensor.

[0023] (8) In the power generation sensor according to any of (1) to (7) above, the first external electrode terminal has a first mounting surface that is fixed to the mounting substrate. The second external electrode terminal has a second mounting surface that is fixed to the mounting substrate.

[0024] Therefore, it becomes easier to mount the power generation sensor on the substrate. (9) In the power generation sensor according to (8) above, the first length of the first mounting surface in a direction perpendicular to the axial direction of the magnetic wire is greater than the second length of the first mounting surface in the axial direction of the magnetic wire.

[0025] The weight of the power generation sensor, which is concentrated in the axial direction of the magnetic wire, is distributed in a direction perpendicular to the axial direction of the magnetic wire. Therefore, when the first and second mounting surfaces are soldered to the pads of the mounting substrate, the first and second external electrode terminals are self-aligned with respect to the mounting substrate. Because the power generation sensor is positioned appropriately, the detection operation of the power generation sensor becomes stable.

[0026] (10) In the power generation sensor according to (8) above, the coil body includes a first end facing the first soft magnetic body and a second end facing the second soft magnetic body. In a plan view from the axial direction of the magnetic wire, the portion of the first end opposite to the first mounting surface with respect to the magnetic wire is exposed from the first soft magnetic body. In a plan view from the axial direction of the magnetic wire, the portion of the second end opposite to the second mounting surface with respect to the magnetic wire is exposed from the second soft magnetic body.

[0027] Therefore, the first and second soft magnetic components can be miniaturized without significantly impairing the magnetic flux induction function from the magnetic field source to the magnetic wire. The power generation sensor can be miniaturized while maintaining its performance.

[0028] (11) In the power generation sensor according to any of (1) to (10) above, the first soft magnetic body is provided with a first through hole into which a magnetic wire is inserted. The second soft magnetic body is provided with a second through hole into which a magnetic wire is inserted.

[0029] Therefore, the magnetic wire can be positioned close to the first and second soft magnetic components. More magnetic flux from the magnetic field source can be guided through the first and second soft magnetic components to the end of the magnetic wire. The Great Barkhausen effect can be sufficiently induced in the magnetic wire. The output signal strength from the power generation sensor increases.

[0030] (12) In the power generation sensor according to any of (1) to (10) above, the first soft magnetic body is provided with a first groove into which a magnetic wire is inserted. The second soft magnetic body is provided with a second groove into which a magnetic wire is inserted.

[0031] Therefore, the magnetic wire can be positioned close to the first and second soft magnetic components. More magnetic flux from the magnetic field source can be guided through the first and second soft magnetic components to the end of the magnetic wire. The Great Barkhausen effect can be sufficiently induced in the magnetic wire. The output signal strength from the power generation sensor increases.

[0032] (13) In the power generation sensor according to any of (1) to (12) above, the first external electrode terminal is fitted into the first fitting groove provided in the first soft magnetic body.

[0033] Therefore, the first external electrode terminal can be attached to the first soft magnetic component without using adhesive. This reduces the cost of the power generation sensor.

[0034] (14) In a power generation sensor according to any of (1) to (13) above, the first soft magnetic component includes a first soft magnetic projection that protrudes from the first soft magnetic body toward the second soft magnetic body. The second soft magnetic component includes a second soft magnetic projection that protrudes from the second soft magnetic body toward the first soft magnetic body. The first soft magnetic projection and the second soft magnetic projection are separated from the coil body. The second soft magnetic projection is separated from the first soft magnetic projection.

[0035] The first soft magnetic protrusion and the second soft magnetic protrusion guide the magnetic flux from the magnetic field generation source toward the vicinity of the center of the magnetic wire to the end of the magnetic wire. Therefore, the first soft magnetic component and the second soft magnetic component can guide more magnetic flux from the magnetic field generation source to the end of the magnetic wire. The large Barkhausen effect can be sufficiently induced in the magnetic wire. The output signal intensity from the power generation sensor increases.

[0036] (15) In the power generation sensor according to (14) above, the first width of the first soft magnetic protrusion and the second width of the second soft magnetic protrusion are larger than the diameter of the magnetic wire.

[0037] Therefore, the first soft magnetic component and the second soft magnetic component can guide more magnetic flux from the magnetic field generation source to the end of the magnetic wire. The large Barkhausen effect can be sufficiently induced in the magnetic wire. The output signal intensity from the power generation sensor increases.

[0038] [Details of Embodiments of the Present Disclosure] Hereinafter, embodiments of the present disclosure will be described based on the drawings. Relative terms such as "upper", "lower", "front", or "rear" are used in this specification to explain the relative positional relationship of a certain structure or a certain part with respect to another structure or another part shown in the figure. Relative terms such as "upper", "lower", "front", or "rear" are intended to include positional relationships different from the positional relationships shown in the figure in addition to the positional relationships shown in the figure. For example, when the device shown in the figure is turned upside down, a certain structure or a certain part described as being located "above" another structure or another part will be located "below" another structure or another part. The same or corresponding parts in the following drawings are given the same reference numerals, and the description thereof will not be repeated.

[0039] (Embodiment 1) Referring to FIGS. 1 to 7, the power generation sensor 1 of Embodiment 1 will be described. As shown in FIGS. 1 to 3, the power generation sensor 1 may be placed on a mounting substrate 5 such as a printed circuit board. Specifically, the mounting substrate 5 includes a front surface 5a and a back surface 5b opposite to the front surface 5a. The power generation sensor 1 is mounted on the front surface 5a of the mounting substrate 5. The power generation sensor 1 mainly includes a first soft magnetic component 10, a second soft magnetic component 20, a magnetic wire 7, a coil 30, a first external electrode terminal 40, and a second external electrode terminal 50.

[0040] Referring to FIGS. 1 to 4, the first soft magnetic component 10 includes a first soft magnetic main body 10a. Since the first external electrode terminal 40 is attached to the first soft magnetic main body 10a, the first soft magnetic main body 10a is preferably formed of an electrically insulating material. The material of the first soft magnetic main body 10a is, for example, a soft magnetic insulating material such as Mn-Zn ferrite or Ni-Zn ferrite, and preferably Ni-Zn ferrite.

[0041] The first soft magnetic main body 10a has, for example, a rectangular parallelepiped shape. The first soft magnetic main body 10a includes a main surface 11, a main surface 12 opposite to the main surface 11, a lower surface 13, an upper surface 14 opposite to the lower surface 13, a side surface 15, and a side surface 16 opposite to the side surface 15.

[0042] The main surface 11 faces the first end 32 of the coil body 31. The main surface 11 faces, for example, one side in the first direction DR1. The main surface 12 faces, for example, the other side in the first direction DR1. The main surfaces 11 and 12 extend, for example, in a second direction DR2 perpendicular to the first direction DR1 and a third direction DR3 perpendicular to the first direction DR1 and the second direction DR2. The lower surface 13 and the upper surface 14 are connected to the main surfaces 11 and 12. The lower surface 13 faces, for example, one side in the second direction DR2 and faces the front surface 5a of the mounting substrate 5. The upper surface 14 faces, for example, the other side in the second direction DR2. The lower surface .....

[0043] Sides 15 and 16 are connected to the main surfaces 11 and 12, the bottom surface 13, and the top surface 14, respectively. Side 15 faces, for example, one side of the third direction DR3. Sides 15 and 16 extend, for example, in the first direction DR1 and the second direction DR2. Side 16 faces, for example, the other side of the third direction DR3. As shown in Figure 3, on both sides of the third direction DR3, the first soft magnetic body portion 10a protrudes from the coil body 31. That is, in the third direction DR3, side 15 and 16 are further away from the magnetic wire 7 than the coil body 31.

[0044] A first through-hole 17 is provided in the first soft magnetic body portion 10a. The first through-hole 17 extends from the main surface 11 to the main surface 12. The first through-hole 17 is provided, for example, at the center of the main surface 11 and the center of the main surface 12. The magnetic wire 7 is inserted into the first through-hole 17. The magnetic wire 7 passes through the first soft magnetic body portion 10a. The first soft magnetic body portion 10a may support the magnetic wire 7. The diameter of the first through-hole 17 is slightly larger than the diameter of the magnetic wire 7. Since almost no stress is applied to the magnetic wire 7 from the first soft magnetic body portion 10a, the magnetic wire 7 can appropriately exhibit the Great Barkhausen effect in response to the magnetic flux from the magnetic field source (for example, the rotating magnet 80 shown in Figures 8 and 9).

[0045] Referring to Figures 1 to 4, the second soft magnetic component 20 includes a second soft magnetic body portion 20a. Since the second external electrode terminal 50 is attached to the second soft magnetic body portion 20a, the second soft magnetic body portion 20a is preferably made of an electrically insulating material. The material of the second soft magnetic body portion 20a is a soft magnetic insulating material such as Mn-Zn ferrite or Ni-Zn ferrite, and is preferably Ni-Zn ferrite.

[0046] The second soft magnetic body portion has, for example, the shape of a rectangular parallelepiped. The second soft magnetic body portion includes a main surface 21, a main surface 22 opposite to the main surface 21, a bottom surface 23, an top surface 24 opposite to the bottom surface 23, a side surface 25, and a side surface 26 opposite to the side surface 25.

[0047] The main surface 21 faces the second end 33 of the coil body 31 and the main surface 11. The main surface 21 faces, for example, the other side of the first direction DR1. The main surface 22 faces, for example, one side of the first direction DR1. The main surfaces 21 and 22 extend, for example, in the second direction DR2 and the third direction DR3. The lower surface 23 and the upper surface 24 are connected to the main surfaces 21 and 22. The lower surface 23 faces, for example, one side of the second direction DR2 and faces the front surface 5a of the mounting substrate 5. The upper surface 24 faces, for example, the other side of the second direction DR2. The lower surface 23 and the upper surface 24 extend, for example, in the first direction DR1 and the third direction DR3.

[0048] Sides 25 and 26 are connected to the main surfaces 21 and 22, the bottom surface 23, and the top surface 24, respectively. Side 25 faces, for example, one side of the third direction DR3. Side 26 faces, for example, the other side of the third direction DR3. Sides 25 and 26 extend, for example, in the first direction DR1 and the second direction DR2. As shown in Figure 3, on both sides of the third direction DR3, the second soft magnetic body portion 20a protrudes from the coil body 31. That is, in the third direction DR3, side 25 and 26 are further away from the magnetic wire 7 than the coil body 31.

[0049] A second through-hole 27 is provided in the second soft magnetic body portion 20a. The second through-hole 27 extends from the main surface 21 to the main surface 22. The second through-hole 27 is provided, for example, at the center of the main surface 21 and the center of the main surface 22. The magnetic wire 7 is inserted into the second through-hole 27. The magnetic wire 7 passes through the second soft magnetic body portion 20a. The second soft magnetic body portion 20a may support the magnetic wire 7. The diameter of the second through-hole 27 is slightly larger than the diameter of the magnetic wire 7. Since almost no stress is applied to the magnetic wire 7 from the second soft magnetic body portion 20a, the magnetic wire 7 can appropriately exhibit the Great Barkhausen effect in response to the magnetic flux from the magnetic field source (for example, the rotating magnet 80 shown in Figures 8 and 9).

[0050] The first soft magnetic component 10 and the second soft magnetic component 20 guide the magnetic flux from a magnetic field source (for example, the rotating magnet 80 shown in Figures 8 and 9) to the ends 7a and 7b of the magnetic wire 7. Referring to Figure 3, the length L1 of the first soft magnetic body portion 10a in the third direction DR3 is the length between side surface 15 and side surface 16, and may be greater than the diameter R of the coil body 31. The length L2 of the second soft magnetic body portion 20a in the third direction DR3 is the length between side surface 25 and side surface 26, and may be greater than the diameter R of the coil body 31. As a result, more magnetic flux from the magnetic field source (for example, the rotating magnet 80 shown in Figures 8 and 9) can be guided to the ends 7a and 7b of the magnetic wire 7. Referring to Figures 1 to 3, the first soft magnetic component 10 and the second soft magnetic component 20 are configured symmetrically with respect to a plane 7d that passes through the center 7c of the magnetic wire 7 and is perpendicular to the axial direction (first direction DR1) of the magnetic wire 7. The first soft magnetic main body 10a and the second soft magnetic main body 20a are configured symmetrically with respect to the plane 7d.

[0051] Referring to Figures 1 to 4, the magnetic wire 7 can exhibit the Great Barkhausen effect. The magnetic wire 7 includes a core portion (not shown) and a peripheral portion (not shown) surrounding the core portion. One of the core portion and the peripheral portion is a soft magnetic layer. The other of the core portion and the peripheral portion is a hard magnetic layer. When the hard magnetic layer and the soft magnetic layer are magnetized in the same direction along the axial direction (first direction DR1) of the magnetic wire 7, when the strength of an external magnetic field in the opposite direction to their magnetization direction reaches a reference magnetic field strength, the magnetization direction of the soft magnetic layer reverses, but the magnetization direction of the hard magnetic layer does not. At this time, the Great Barkhausen effect is exhibited. The magnetic wire 7 is made of, for example, a bicalloy alloy (FeCoV alloy). For example, a magnetic wire 7 capable of exhibiting the Great Barkhausen effect can be obtained by drawing a bicalloy alloy into a wire shape and then twisting it.

[0052] The magnetic wire 7 includes an end 7a, an end 7b, and a center 7c, where the ends 7a and 7b are the ends of the magnetic wire 7 in the axial direction (first direction DR1). The center 7c is the center of the magnetic wire 7 in the axial direction. The diameter of the magnetic wire 7 is preferably half or less of the diameter R of the coil body 31.

[0053] The magnetic wire 7 may protrude from the first end 32 and the second end 33 of the coil body 31. The length of the magnetic wire 7 protruding from the first end 32 of the coil body 31 in the axial direction (first direction DR1) of the magnetic wire 7 may be equal to the length of the magnetic wire 7 protruding from the second end 33 of the coil body 31 in the axial direction of the magnetic wire 7. The magnetic wire 7 may protrude from the first soft magnetic body portion 10a on the side opposite to the coil body 31 relative to the first soft magnetic body portion 10a. The magnetic wire 7 may protrude from the second soft magnetic body portion 20a on the side opposite to the coil body 31 relative to the second soft magnetic body portion 20a. The length of the magnetic wire 7 protruding from the first soft magnetic body portion 10a in the axial direction of the magnetic wire 7 may be equal to the length of the magnetic wire 7 protruding from the second soft magnetic body portion 20a in the axial direction of the magnetic wire 7.

[0054] Referring to Figures 1 to 4, the coil 30 includes a coil body 31, a first coil terminal wire 34, and a second coil terminal wire 35.

[0055] The coil body 31 is formed by winding a coil wire 36 (see Figure 5) around a magnetic wire 7. The coil wire 36 has a strength of 200 N / mm ２ It may be formed from a high-tensile strength wire having the above tensile strength. The tensile strength of the coil wire 36 is 250 to 500 N / mm ２ Preferably, 275 to 400 N / mm ２ More preferably, 300-350 N / mm ２This is even more preferable. In this specification, the tensile strength is measured by the method specified in JIS (Japanese Industrial Standards) C 3216-3:2011. When the magnetic wire 7 exhibits the Great Barkhausen effect, a pulse voltage is induced in the coil body 31. The coil body 31 includes a first end 32 facing the first soft magnetic body portion 10a and a second end 33 facing the second soft magnetic body portion 20a.

[0056] As shown in Figure 5, the coil wire 36 includes a conductor 36a and an insulating layer 36b covering the conductor 36a. The material of the conductor 36a is, for example, copper, copper alloy, aluminum, aluminum alloy, nickel, silver, soft iron, steel, or stainless steel, with silver-containing copper alloy being particularly preferred. The silver content in the silver-containing copper alloy is preferably 0.1 to 1% by mass. The diameter of the conductor 36a is, for example, 0.01 to 0.5 mm. The insulating layer 36b may be a single layer or multiple layers. The thickness of the insulating layer 36b is, for example, 1 to 100 μm. The insulating layer 36b is formed of an insulating resin such as polyurethane, polyimide, polyamide-imide, polyester-imide, polyester, polyolefin, polyethersulfone, polyphenylene sulfide, polyetheretherketone, or polytetrafluoroethylene. The material of the insulating layer 36b is preferably polyurethane.

[0057] The coil body 31 is formed, for example, from a self-fusing coil as shown in Figure 5, and the coil body 31 is not directly wound around the magnetic wire 7. The inner diameter of the coil body 31 is slightly larger than the diameter of the magnetic wire 7. Therefore, almost no stress is applied from the coil body 31 to the magnetic wire 7. Depending on the magnetic flux from the magnetic field source (for example, the rotating magnet 80 shown in Figures 8 and 9), the magnetic wire 7 can appropriately exhibit the large Barkhausen effect.

[0058] Specifically, in the self-fusing coil, the coil wire 36 is formed into a coil shape by being fixed by the fusing part 38. The self-fusing coil is formed by winding a self-fusing wire 37 (see FIG. 6) including the coil wire 36 and a fusing layer 39 covering the coil wire 36 in a coil shape while heating and then cooling it. The fusing layer 39 becomes the fusing part 38. The fusing layer 39 is formed of a material mainly containing a resin such as polyamide, nylon, or phenoxy resin. The material of the fusing layer 39 is preferably polyamide. The thickness of the fusing layer 39 before fusing is, for example, 5 to 300 μm.

[0059] The first coil terminal wire 34 and the second coil terminal wire 35 are both ends of the coil 30. The first coil terminal wire 34 and the second coil terminal wire 35 are each connected to the coil body 31. Similar to the coil wire 36, the first coil terminal wire 34 and the second coil terminal wire 35 each include a conductor 36a (see FIG. 5) and an insulating layer 36b covering the conductor 36a. The first coil terminal wire 34 and the second coil terminal wire 35 may each be a single wire. The first coil terminal wire 34 and the second coil terminal wire 35 may each be formed of a high-tensile wire having a tensile strength of ２ 200 N / mm or more. The tensile strength of each of the first coil terminal wire 34 and the second coil terminal wire 35 is preferably 250 to 500 N / mm ２ more preferably 275 to 400 N / mm ２ even more preferably 300 to 350 N / mm. ２

[0060] Referring to Figures 1 to 4, the first external electrode terminal 40 is formed of a weldable material. The material of the first external electrode terminal 40 is not particularly limited, but may be, for example, aluminum (Al), copper (Cu), nickel (Ni), or tungsten (W), or alloys thereof. The material of the first external electrode terminal 40 is preferably phosphor bronze. The first external electrode terminal 40 can be more reliably resistance welded by being coated with a plating layer. The material of the plating layer is not particularly limited, but may be tin (Sn). The first external electrode terminal 40 is, for example, a first lead frame. The first lead frame is formed to match the shape of the first soft magnetic body portion 10a. The first external electrode terminal 40 has, for example, a substantially C-shape. The first external electrode terminal 40 includes, for example, plates 41, 42, and 43.

[0061] The plate 41 faces the main surface 12 of the first soft magnetic body portion 10a. A through hole 47 is provided in the plate 41. The through hole 47 is, for example, located in the center of the plate 41. The diameter of the through hole 47 is larger than the diameter of the magnetic wire 7 and the diameter of the first through hole 17. The magnetic wire 7 is inserted into the through hole 47. The magnetic wire 7 penetrates the plate 41. The plate 41 is separated from the magnetic wire 7.

[0062] Plate 42 is connected to plate 41. Plate 42 faces the lower surface 13 of the first soft magnetic component 10 and the front surface 5a of the mounting substrate 5. Plate 42 has a first mounting surface 42a that faces the front surface 5a of the mounting substrate 5. The first mounting surface 42a is fixed to a land (not shown) on the mounting substrate 5 using a conductive bonding member (not shown) such as solder.

[0063] Plate 43 is connected to plate 41. Plate 43 faces the upper surface 14 of the first soft magnetic component 10. Plate 43 has a first joining plane 43a. As shown in Figure 7, the first coil terminal wire 34 is joined to the first joining plane 43a by welding. The welding is preferably resistance welding, but may also be arc welding or the like. The conditions for resistance welding (for example, the current flowing through the welding electrodes sandwiching the first coil terminal wire 34 and the first external electrode terminal 40, the pressure applied to the first coil terminal wire 34 and the first external electrode terminal 40 by the welding electrodes, and the contact resistance between the first coil terminal wire 34 and the first external electrode terminal 40) are appropriately set according to the material of the first coil terminal wire 34 and the material of the first external electrode terminal 40, etc.

[0064] The first external electrode terminal 40 is attached to the first soft magnetic body portion 10a. For example, the first external electrode terminal 40 is fitted into the first soft magnetic body portion 10a. The first external electrode terminal 40 may be in contact with the first soft magnetic body portion 10a. The first external electrode terminal 40 may be fixed to the first soft magnetic body portion 10a using an adhesive.

[0065] Referring to Figures 1 to 4, the second external electrode terminal 50 is formed of a weldable material. The material of the second external electrode terminal 50 is not particularly limited, but may be, for example, aluminum (Al), copper (Cu), nickel (Ni), or tungsten (W), or alloys thereof. Preferably, the material of the second external electrode terminal 50 is phosphor bronze. The second external electrode terminal 50 can be more reliably resistance welded by being coated with a plating layer. The material of the plating layer is not particularly limited, but may be tin (Sn). The second external electrode terminal 50 is, for example, a second lead frame. The second lead frame is formed to match the shape of the second soft magnetic body portion 20a. The second external electrode terminal 50 has, for example, a substantially C-shape. The second external electrode terminal 50 includes, for example, plates 51, 52, and 53.

[0066] The plate 51 faces the main surface 22 of the second soft magnetic body portion 20a. A through hole 57 is provided in the plate 51. The through hole 57 is, for example, located in the center of the plate 51. The diameter of the through hole 57 is larger than the diameter of the magnetic wire 7 and the diameter of the second through hole 27. The magnetic wire 7 is inserted into the through hole 57. The magnetic wire 7 passes through the plate 51. The plate 51 is separated from the magnetic wire 7.

[0067] Plate 52 is connected to plate 51. Plate 52 faces the lower surface 23 of the second soft magnetic component 20 and the front surface 5a of the mounting substrate 5. Plate 52 has a second mounting surface 52a that faces the front surface 5a of the mounting substrate 5. The second mounting surface 52a is fixed to a land (not shown) on the mounting substrate 5 using a conductive bonding member (not shown) such as solder.

[0068] Plate 53 is connected to plate 51. Plate 53 faces the upper surface 24 of the second soft magnetic component 20. Plate 53 has a second joining plane 53a. The second coil terminal wire 35 is joined to the second joining plane 53a by welding. The welding is preferably resistance welding, but may also be arc welding or the like. The conditions for resistance welding (for example, the current flowing through the welding electrodes sandwiching the first coil terminal wire 34 and the first external electrode terminal 40, the pressure applied to the first coil terminal wire 34 and the first external electrode terminal 40 by the welding electrodes, and the contact resistance between the first coil terminal wire 34 and the first external electrode terminal 40) are appropriately set according to the material of the first coil terminal wire 34 and the material of the first external electrode terminal 40, etc.

[0069] The second external electrode terminal 50 is attached to the second soft magnetic body portion 20a. For example, the second external electrode terminal 50 is fitted into the second soft magnetic body portion 20a. The second external electrode terminal 50 may be in contact with the second soft magnetic body portion 20a. The second external electrode terminal 50 may be fixed to the second soft magnetic body portion 20a using an adhesive.

[0070] The magnetic wire 7 may protrude from the plate 41 of the first external electrode terminal 40 on the side opposite to the coil body 31 relative to the plate 41 of the first external electrode terminal 40. The magnetic wire 7 may also protrude from the plate 51 of the second external electrode terminal 50 on the side opposite to the coil body 31 relative to the plate 51 of the second external electrode terminal 50. The length of the magnetic wire 7 protruding from the plate 41 of the first external electrode terminal 40 in the axial direction (first direction DR1) of the magnetic wire 7 may be equal to the length of the magnetic wire 7 protruding from the plate 51 of the second external electrode terminal 50 in the axial direction of the magnetic wire 7. The first external electrode terminal 40 and the second external electrode terminal 50 are configured symmetrically with respect to the plane 7d.

[0071] The operation of the power generation sensor 1 of this embodiment will now be described. When the strength of the external magnetic field reaches the reference magnetic field strength, the Great Barkhausen effect occurs in the magnetic wire 7. A voltage is induced in the coil body 31, which is formed by winding a coil wire 36 around the magnetic wire 7. This voltage is output to the lands (not shown) and electrical wiring (not shown) of the mounting substrate 5 through the first coil terminal wire 34, the second coil terminal wire 35, the first external electrode terminal 40, and the second external electrode terminal 50. This voltage is constant regardless of the speed of change of the external magnetic field. When the external magnetic field is an alternating magnetic field, a positive pulse voltage and a negative pulse voltage are generated, and the absolute value of the negative pulse voltage is approximately equal to the positive pulse voltage. Therefore, the power generation sensor 1 can be used as a rotation sensor or a position sensor, etc.

[0072] Referring to Figures 8 and 9, it will be explained that the power generation sensor 1 of this embodiment can be used as a rotation sensor.

[0073] As shown in Figure 8, the power generation sensor 1 is mounted on the front surface 5a of the mounting substrate 5. Specifically, the first mounting surface 42a of the first external electrode terminal 40 and the second mounting surface 52a of the second external electrode terminal 50 are fixed to the lands (not shown) of the mounting substrate 5 using a conductive bonding member (not shown), such as solder. The rotating magnet 80 is positioned opposite the back surface 5b of the mounting substrate 5, the lower surface 13 of the first soft magnetic body portion 10a, and the lower surface 23 of the second soft magnetic body portion 20a. The rotating magnet 80 is a multi-pole magnet, such as a two-pole magnet, and includes an N-pole portion 81 and an S-pole portion 82. The rotation axis 80c of the rotating magnet 80 lies on the plane 7d. The rotation axis 80c passes through the center 7c of the magnetic wire 7 and is perpendicular to the axial direction (first direction DR1) of the magnetic wire 7. As the rotating magnet 80 rotates around the rotation axis 80c, an alternating magnetic field is applied from the rotating magnet 80 to the power generation sensor 1. If the rotating magnet 80 is a bipolar magnet, a pulse voltage is generated from the power generation sensor 1 every 180 degrees the rotating magnet 80 rotates. By detecting this pulse voltage, the rotation speed of the rotating magnet 80 can be detected. In this way, the power generation sensor 1 functions as a rotation sensor.

[0074] As shown in Figure 9, the rotating magnet 80 may be positioned facing the upper surface 14 of the first soft magnetic body portion 10a and the upper surface 24 of the second soft magnetic body portion 20a.

[0075] The operation of the power generation sensor 1 of this embodiment will be explained in comparison with the power generation sensors of the first and second comparative examples.

[0076] In the power generation sensor of the first comparative example, protrusions are provided on the first external electrode terminal 40 and the second external electrode terminal 50, the first coil terminal wire 34 is wrapped around the protrusion of the first external electrode terminal 40, and the second coil terminal wire 35 is wrapped around the protrusion of the second external electrode terminal 50. Because protrusions are provided on the first external electrode terminal 40 and the second external electrode terminal 50, the size of the power generation sensor 1 is increased. Furthermore, when vibration or mechanical shock is applied to the first coil terminal wire 34 and the second coil terminal wire 35, the first coil terminal wire 34 and the second coil terminal wire 35 may detach from the protrusion of the first external electrode terminal 40 and the protrusion of the second external electrode terminal 50, respectively. Therefore, the reliability of the electrical connection between the first coil terminal wire 34 and the first external electrode terminal 40, and the reliability of the electrical connection between the second coil terminal wire 35 and the second external electrode terminal 50 are low.

[0077] In the second comparative example of the power generation sensor, the first coil terminal wire 34 and the second coil terminal wire 35 are soldered to the first external electrode terminal 40 and the second external electrode terminal 50, respectively. The first coil terminal wire 34 and the second coil terminal wire 35 are formed of a conductor 36a (see Figure 5) covered with an insulating layer 36b. Therefore, the first coil terminal wire 34 and the second coil terminal wire 35 must be soldered to the first external electrode terminal 40 and the second external electrode terminal 50 at a temperature high enough to melt the insulating layer 36b. Soldering at such high temperatures causes solder erosion of the conductor 36a. As a result, the reliability of the electrical connection between the first coil terminal wire 34 and the first external electrode terminal 40, and the reliability of the electrical connection between the second coil terminal wire 35 and the second external electrode terminal 50 are low.

[0078] Furthermore, in order to mitigate the adverse effects caused by solder erosion, stranded wire may be used as the conductor 36a included in the first coil terminal wire 34 and the second coil terminal wire 35. However, when stranded wire is used as the conductor 36a, it becomes difficult to set the conditions (for example, soldering time and soldering temperature) for soldering the first coil terminal wire 34 and the second coil terminal wire 35 to the first external electrode terminal 40 and the second external electrode terminal 50, respectively. As a result, the reliability of the electrical connection between the first coil terminal wire 34 and the first external electrode terminal 40, and the reliability of the electrical connection between the second coil terminal wire 35 and the second external electrode terminal 50 are low.

[0079] In contrast, in the power generation sensor 1 of this embodiment, the first coil terminal wire 34 and the second coil terminal wire 35 are joined to the first external electrode terminal 40 and the second external electrode terminal 50, respectively, by welding. There is no need to provide protrusions on the first external electrode terminal 40 and the second external electrode terminal 50. Therefore, the power generation sensor 1 of this embodiment is smaller than the power generation sensor of the first comparative example. In addition, welding provides higher reliability of electrical connection compared to tangle connection and soldering. Therefore, the electrical connection between the coil terminal wire and the external electrode terminal in the power generation sensor 1 of this embodiment (specifically, the electrical connection between the first coil terminal wire 34 and the first external electrode terminal 40, and the electrical connection between the second coil terminal wire 35 and the second external electrode terminal 50) has higher reliability than the electrical connection between the coil terminal wire and the external electrode terminal in the first and second comparative examples.

[0080] Furthermore, since welding does not require the processing of protrusions and entanglement as in the first comparative example, the cost of the power generation sensor 1 of this embodiment is lower than the cost of the power generation sensor of the first comparative example. In welding, since it is not necessary to prepare solder and flux for soldering as in the second comparative example, the cost of the power generation sensor 1 of this embodiment is lower than the cost of the power generation sensor of the second comparative example.

[0081] (Modified Version) Referring to Figure 10, in the first modified version of this embodiment, the first external electrode terminal 40 may include side plates 44a and 44b instead of the plate 43 (see Figures 1 to 4). The side plate 44a faces the side surface 15 of the first soft magnetic body portion 10a. The side plate 44b faces the side surface 16 of the first soft magnetic body portion 10a. The first external electrode terminal 40 is fitted into the first soft magnetic body portion 10a. The side plate 44a may be in contact with the side surface 15 of the first soft magnetic body portion 10a. The side plate 44b may be in contact with the side surface 16 of the first soft magnetic body portion 10a. Similarly, the second external electrode terminal 50 may include a side plate (not shown) instead of the plate 53 (see Figures 1 to 4).

[0082] Referring to Figure 11, in the second modification of this embodiment, the length of the plate 42 of the first external electrode terminal 40 in the third direction DR3 is increased. Specifically, the length L3 of the first mounting surface 42a in the third direction DR3 is greater than the length L4 of the first mounting surface in the axial direction of the magnetic wire 7 (first direction DR1). The length L3 of the first mounting surface 42a is greater than the length L5 of the first bonding plane 43a in the third direction DR3. The length L3 of the first mounting surface 42a is greater than the length L1 of the first soft magnetic body portion 10a in the third direction DR3. The plate 52 of the second external electrode terminal 50 is configured similarly to the plate 42 of the first external electrode terminal 40.

[0083] Referring to Figure 12, in a third modified example of this embodiment, the first soft magnetic body portion 10a is provided with a first groove 18 into which a magnetic wire 7 is inserted, instead of the first through hole 17 (see Figures 1 to 4). Specifically, the first groove 18 is provided on the upper surface 14 and the main surfaces 11 and 12. The first groove 18 extends from the main surface 11 to the main surface 12 and penetrates the first soft magnetic body portion 10a in the first direction DR1. The width of the first groove 18 (length of the first groove 18 in the third direction DR3) is slightly larger than the diameter of the magnetic wire 7. The depth of the first groove 18 (length of the first groove 18 in the second direction DR2) is greater than the diameter of the magnetic wire 7 and the width of the first groove 18.

[0084] Similarly, the second soft magnetic body portion 20a is provided with a second groove (not shown) into which the magnetic wire 7 is inserted, instead of the second through hole 27 (see Figures 1 to 4). Specifically, the second groove is provided on the upper surface 24 and the main surfaces 21 and 22. The second groove extends from the main surface 21 to the main surface 22 and penetrates the second soft magnetic body portion 20a in the first direction DR1. The width of the second groove (length of the second groove in the third direction DR3) is slightly larger than the diameter of the magnetic wire 7. The depth of the second groove (length of the second groove in the second direction DR2) is greater than the diameter of the magnetic wire 7 and the width of the second groove.

[0085] The first external electrode terminal 40 is provided with a groove 48 into which a magnetic wire 7 is inserted, instead of a through hole 47 (see Figures 1 to 4). Specifically, the groove 48 is provided in plates 41 and 43. The groove 48 penetrates plate 41 in the first direction DR1. The groove 48 penetrates plate 43 in the second direction DR2. The width of the groove 48 (length of the groove 48 in the third direction DR3) is slightly larger than the diameter of the magnetic wire 7. The depth of the groove 48 (length of the groove 48 in the second direction DR2) is greater than both the diameter of the magnetic wire 7 and the width of the groove 48.

[0086] Similarly, the second external electrode terminal 50 is provided with a groove (not shown) into which the magnetic wire 7 is inserted, instead of a through hole 57 (see Figures 1 to 4). Specifically, the groove is provided in plates 51 and 53. The groove penetrates plate 51 in the first direction DR1. The groove penetrates plate 53 in the second direction DR2. The width of the groove (length of the groove in the third direction DR3) is slightly larger than the diameter of the magnetic wire 7. The depth of the groove (length of the groove in the second direction DR2) is greater than both the diameter of the magnetic wire 7 and the width of the groove.

[0087] The magnetic wire 7 is inserted along the second direction DR2 into the first groove 18 of the first soft magnetic body portion 10a, the second groove 28 of the second soft magnetic body portion 20a, the groove 48 of the first external electrode terminal 40, and the groove 58 of the second external electrode terminal 50.

[0088] Referring to Figure 13, in the fourth modified example of this embodiment, the first groove 18 of the first soft magnetic component 10 is provided on the side surface 15 and the main surfaces 11 and 12. The first groove 18 extends from the main surface 11 to the main surface 12 and penetrates the first soft magnetic body portion 10a in the first direction DR1. The width of the first groove 18 (length of the first groove 18 in the second direction DR2) is slightly larger than the diameter of the magnetic wire 7. The depth of the first groove 18 (length of the first groove 18 in the third direction DR3) is greater than the diameter of the magnetic wire 7 and the width of the first groove 18.

[0089] The second groove (not shown) of the second soft magnetic component 20 is provided on the side surface 25 and the main surfaces 21 and 22. The second groove extends from the main surface 21 to the main surface 22 and penetrates the second soft magnetic body portion 20a in the first direction DR1. The width of the second groove (length of the second groove in the second direction DR2) is slightly larger than the diameter of the magnetic wire 7. The depth of the second groove (length of the second groove in the third direction DR3) is greater than both the diameter of the magnetic wire 7 and the width of the second groove.

[0090] The groove 48 of the first external electrode terminal 40 is provided in the plate 41. The groove 48 penetrates the plate 41 in the first direction DR1. The width of the groove 48 (length of the groove 48 in the second direction DR2) is slightly larger than the diameter of the magnetic wire 7. The depth of the groove 48 (length of the groove 48 in the third direction DR3) is greater than both the diameter of the magnetic wire 7 and the width of the groove 48.

[0091] Similarly, a groove (not shown) for the second external electrode terminal 50 is provided in the plate 51. The groove penetrates the plate 51 in the first direction DR1. The width of the groove (length of the groove in the second direction DR2) is slightly larger than the diameter of the magnetic wire 7. The depth of the groove (length of the groove for the second external electrode terminal 50 in the third direction DR3) is greater than both the diameter of the magnetic wire 7 and the width of the groove.

[0092] The magnetic wire 7 is inserted along the third direction DR3 into the first groove 18 of the first soft magnetic body portion 10a, the second groove 28 of the second soft magnetic body portion 20a, the groove 48 of the first external electrode terminal 40, and the groove 58 of the second external electrode terminal 50.

[0093] Referring to Figure 14, in the fifth modified example of this embodiment, a first fitting groove 19 is provided on the main surface 12 of the first soft magnetic body portion 10a. The plate 41 is fitted into the first fitting groove 19. Therefore, the first external electrode terminal 40 can be attached to the first soft magnetic body portion 10a without using an adhesive. Similarly, a second fitting groove (not shown) is provided on the main surface 22 of the second soft magnetic body portion 20a. The plate 51 is fitted into the second fitting groove. Therefore, the second external electrode terminal 50 can be attached to the second soft magnetic body portion 20a without using an adhesive.

[0094] Referring to Figure 15, in the sixth modified example of this embodiment, the length L1 of the first soft magnetic body portion 10a in the third direction DR3 is smaller than the diameter R of the coil body 31. The length L2 of the second soft magnetic body portion 20a in the third direction DR3 is smaller than the diameter R of the coil body 31. Therefore, the power generation sensor 1 can be miniaturized. Furthermore, the sides 15, 16 of the first soft magnetic body portion 10a and the sides 25, 26 of the second soft magnetic body portion 20a do not contribute much to inducing magnetic flux from the magnetic field source (for example, the rotating magnet 80 shown in Figures 8 and 9) to the magnetic wire 7. Therefore, even if the lengths L1 and L2 are made smaller than the diameter R of the coil body 31, the performance of the power generation sensor 1 does not deteriorate much.

[0095] (Embodiment 2) The power generation sensor 1 of Embodiment 2 will be described with reference to Figures 16 to 18. The power generation sensor 1 of this embodiment is configured similarly to the power generation sensor 1 of Embodiment 1 (see Figures 1 to 4 and 8), but differs from the power generation sensor 1 of Embodiment 1 in that the first soft magnetic component 10 includes a first soft magnetic projection 10b, and the second soft magnetic component 20 includes a second soft magnetic projection 20b.

[0096] The first soft magnetic projection 10b protrudes from the first soft magnetic body portion 10a toward the second soft magnetic body portion 20a in the axial direction (first direction DR1) of the magnetic wire 7. The first soft magnetic projection 10b is formed of the same material as the first soft magnetic body portion 10a, for example. The first soft magnetic projection 10b is fixed to the first soft magnetic body portion 10a using an adhesive or the like. The first soft magnetic projection 10b is positioned between the coil body 31 and the front surface 5a of the mounting substrate 5. The first soft magnetic projection 10b is separated from the coil body 31. The width W1 of the first soft magnetic projection 10b in the third direction DR3 is greater than the diameter of the magnetic wire 7 and the diameter R of the coil body 31.

[0097] The second soft magnetic projection 20b protrudes from the second soft magnetic body portion 20a toward the first soft magnetic body portion 10a in the axial direction (first direction DR1) of the magnetic wire 7. The second soft magnetic projection 20b is formed of the same material as the second soft magnetic body portion 20a, for example. The second soft magnetic projection 20b is fixed to the second soft magnetic body portion 20a using an adhesive or the like. The second soft magnetic projection 20b is positioned between the coil body 31 and the front surface 5a of the mounting substrate 5. The second soft magnetic projection 20b is separated from the coil body 31. The width W2 of the second soft magnetic projection 20b in the third direction DR3 is greater than the diameter of the magnetic wire 7 and the diameter R of the coil body 31.

[0098] The second soft magnetic projection 20b is separated from the first soft magnetic projection 10b. In the axial direction (first direction DR1) of the magnetic wire 7, the plane 7d lies between the first soft magnetic projection 10b and the second soft magnetic projection 20b. The first soft magnetic projection 10b and the second soft magnetic projection 20b are configured symmetrically with respect to the plane 7d.

[0099] (Modified Versions) Referring to Figures 19 and 20, in the modified power generation sensor 1 of this embodiment, the first soft magnetic body portion 10a and the first soft magnetic projection portion 10b may be an integrated part. The second soft magnetic body portion 20a and the second soft magnetic projection portion 20b may be an integrated part.

[0100] In this modified embodiment, the length of the first soft magnetic body portion 10a in the second direction DR2, the length of the second soft magnetic body portion 20a in the second direction DR2, the length of the first external electrode terminal 40 in the second direction DR2, and the length of the second external electrode terminal 50 in the second direction DR2 are shortened. As a result, the power generation sensor 1 can be miniaturized.

[0101] Specifically, in a modified version of this embodiment, the portion of the first soft magnetic body portion 10a of this embodiment (see Figures 16 and 17) that is opposite to the first mounting surface 42a relative to the magnetic wire 7 is removed. In a plan view from the axial direction (first direction DR1) of the magnetic wire 7, the portion of the first end 32 of the coil body 31 that is opposite to the first mounting surface 42a relative to the magnetic wire 7 is exposed from the first soft magnetic body portion 10a. In a modified version of this embodiment, the portion of the second soft magnetic body portion 20a of this embodiment that is opposite to the second mounting surface 52a relative to the magnetic wire 7 is removed. In a plan view from the axial direction of the magnetic wire 7, the portion of the second end 33 of the coil body 31 that is opposite to the second mounting surface 52a relative to the magnetic wire 7 is exposed from the second soft magnetic body portion 20a. In this embodiment, the portion of the first soft magnetic body 10a (see Figures 16 and 17) that is opposite to the first mounting surface 42a with respect to the magnetic wire 7, and the portion of the second soft magnetic body 20a (see Figures 16 and 17) that is opposite to the second mounting surface 52a with respect to the magnetic wire 7, are far from the magnetic field source (for example, the rotating magnet 80 shown in Figures 8 and 9) and do not contribute much to inducing magnetic flux from the magnetic field source to the magnetic wire 7. Therefore, even if these portions are removed, the performance of the power generation sensor 1 will hardly change.

[0102] In a modified version of this embodiment, a first groove 18 is provided on the upper surface 14 of the first soft magnetic body portion 10a instead of the first through hole 17 of this embodiment. A second groove 28 is provided on the upper surface 24 of the second soft magnetic body portion 20a instead of the second through hole 27 of this embodiment. The depths of the first groove 18 and the second groove 28 in the modified version of this embodiment may be smaller than the diameter of the magnetic wire 7. A groove 48 is provided on the plates 41 and 43 of the first external electrode terminal 40 instead of the through hole 47 of this embodiment. A groove 58 is provided on the plates 51 and 53 of the second external electrode terminal 50 instead of the through hole 57 of this embodiment.

[0103] (Embodiment 3) The power generation sensor 1 of Embodiment 3 will be described with reference to Figures 21 to 23. The power generation sensor 1 is configured similarly to the power generation sensor 1 of the modified embodiment 2 (see Figures 19 and 20), but further includes a case 60.

[0104] The case 60 houses the magnetic wire 7, the coil 30, the first soft magnetic component 10, the second soft magnetic component 20, the first external electrode terminal 40, and the second external electrode terminal 50. The material of the case 60 is not particularly limited, but examples include polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or liquid crystal polymer (LCP). LCP is an aromatic polyester resin. LCP is particularly preferred as the material of the case 60. The case 60 includes a front wall 61, a rear wall 62 opposite the front wall 61, an upper wall 63, a side wall 64, and a side wall 65 opposite the side wall 64. The portion of the case 60 opposite the upper wall 63 is an opening 66.

[0105] The front wall 61 faces the main surface 12 of the first soft magnetic body portion 10a and the plate 41 of the first external electrode terminal 40. An opening 61a is provided in the front wall 61. The end 7a of the magnetic wire 7 is exposed from the front wall 61 at the opening 61a. The rear wall 62 faces the main surface 22 of the second soft magnetic body portion 20a and the plate 51 of the second external electrode terminal 50. An opening 62a is provided in the rear wall 62. The end 7b of the magnetic wire 7 is exposed from the rear wall 62 at the opening 62a. The length of the magnetic wire 7 in the first direction DR1 is shorter than the length of the case 60 in the first direction DR1. The length of the case 60 in the first direction DR1 is the distance between the outer surface of the front wall 61 and the outer surface of the rear wall 62 in the first direction DR1.

[0106] The upper wall 63 faces the upper surface 14 of the first soft magnetic body portion 10a, the upper surface 24 of the second soft magnetic body portion 20a, the plate 43 of the first external electrode terminal 40, and the plate 53 of the second external electrode terminal 50. The upper wall 63 is connected to the front wall 61 and the rear wall 62.

[0107] The side wall 64 faces the side surface 15 of the first soft magnetic body portion 10a and the side surface 25 of the second soft magnetic body portion 20a. The side wall 64 is connected to the front wall 61, the rear wall 62, and the top wall 63. Openings 64a and 64b are provided in the side wall 64. The side wall 65 faces the side surface 16 of the first soft magnetic body portion 10a and the side surface 26 of the second soft magnetic body portion 20a. The side wall 65 is connected to the front wall 61, the rear wall 62, and the top wall 63. Openings 65a and 65b are provided in the side wall 65.

[0108] The first soft magnetic projection 10b has projections 71 and 72 extending in the third direction DR3. The second soft magnetic projection 20b has projections 73 and 74 extending in the third direction DR3. Projection 71 fits into the opening 64a. Projection 72 fits into the opening 65a. Projection 73 fits into the opening 64b. Projection 74 fits into the opening 65b. In this way, the case 60 is fixed to the first soft magnetic component 10 and the second soft magnetic component 20. The projections 71, 72, 73, and 74 may be further fixed to the case 60 using adhesive. The projections 71, 72, 73, and 74 and the openings 64a, 64b, 65a, and 65b may be omitted, and the case 60 may be fixed to the first soft magnetic component 10 and the second soft magnetic component 20 using adhesive.

[0109] The coil body 31, the first soft magnetic component 10, and the second soft magnetic component 20, or the case 60, may be coated with adhesive 76 (see Figure 23), and the case 60 may be fixed to the coil body 31, the first soft magnetic component 10, and the second soft magnetic component 20 using the adhesive 76. The magnetic wire 7 may be fixed to the case 60 using adhesive 77 applied to the ends 7a and 7b of the magnetic wire 7. To avoid the adhesive 77 applying stress to the magnetic wire 7, the adhesive 77 is preferably a silicone resin adhesive having a hardness of durometer A90 or less.

[0110] In place of the power generation sensor 1 in the modified example of Embodiment 2, the power generation sensor 1 of Embodiment 1, its modified examples, and Embodiment 2 may further include a case 60.

[0111] Embodiments 1–3 and their variations disclosed herein should be considered in all respects to be illustrative and not restrictive. To the extent that they do not contradict each other, at least two of Embodiments 1–3 and their variations disclosed herein can be combined. The scope of this disclosure is indicated by the claims rather than the embodiments described above, and all modifications within the scope of the claims are intended to be included in the meaning of equivalences and within the scope.

[0112] 1 Power generation sensor, 5 Mounting substrate, 5a Front surface, 5b Back surface, 7 Magnetic wire, 7a, 7b Ends, 7c Center, 7d Plane, 10 First soft magnetic component, 10a First soft magnetic body, 10b First soft magnetic projection, 11, 12 Main surface, 13 Bottom surface, 14 Top surface, 15, 16 Side surface, 17 First through hole, 18 First groove, 19 Fitting groove, 20 Second soft magnetic component, 20a Second soft magnetic body, 20b Second soft magnetic projection, 21, 22 Main surface, 23 Bottom surface, 24 Top surface, 25, 26 Side surface, 27 Second through hole, 28 Second groove, 30 Coil, 31 Coil body, 32 First end, 33 Second end, 34 First coil terminal wire, 35 Second coil terminal wire, 36 Coil wire, 36a Conductor, 36b Insulating layer, 37 Self-fusing wire, 38 Fusion part, 39 Fusion layer, 40 First external electrode terminals, 41, 42, 43 Plate, 42a First mounting surface, 43a First bonding plane, 44a, 44b Side plate, 47 Through hole, 48 Groove, 50 Second external electrode terminals, 51, 52, 53 Plate, 52a Second mounting surface, 53a Second bonding plane, 57 Through hole, 58 Groove, 60 Case, 61 Front wall, 61a Opening, 62 Rear wall, 62a Opening, 63 Top wall, 64, 65 Side walls, 64a, 64b, 65a, 65b Opening, 66 Opening, 71, 72, 73, 74 Protrusion, 76, 77 Adhesive, 80 Rotating magnet, 80c Rotating axis, 81 North pole portion, 82 South pole portion.

Claims

1. A power generation sensor comprising: a first soft magnetic component including a first soft magnetic body; a second soft magnetic component including a second soft magnetic body; a magnetic wire capable of exhibiting the Great Barkhausen effect; a coil including a coil body, a first coil terminal wire connected to the coil body, and a second coil terminal wire connected to the coil body; a first external electrode terminal mounted on the first soft magnetic body; and a second external electrode terminal mounted on the second soft magnetic body, wherein at least a portion of the magnetic wire is disposed within the coil body; the coil body is disposed between the first soft magnetic body and the second soft magnetic body; the first coil terminal wire is joined to the first external electrode terminal by welding; and the second coil terminal wire is joined to the second external electrode terminal by welding.

2. The first coil terminal wire and the second coil terminal wire each have a load capacity of 200 N / mm². ２ The power generation sensor according to claim 1, having the above tensile strength.

3. The power generation sensor according to claim 2, wherein the first coil terminal wire and the second coil terminal wire are each single wires.

4. The power generation sensor according to any one of claims 1 to 3, wherein the first external electrode terminal is a first lead frame having a first bonding plane, the first coil terminal wire is joined to the first bonding plane by welding, and the second external electrode terminal is a second lead frame having a second bonding plane, the second coil terminal wire is joined to the second bonding plane by welding.

5. The power generation sensor according to any one of claims 1 to 4, wherein the first coil terminal wire is joined to the first external electrode terminal by resistance welding, and the second coil terminal wire is joined to the second external electrode terminal by resistance welding.

6. The power generation sensor according to any one of claims 1 to 5, wherein the coil body is formed of a self-fusing coil.

7. The coil body includes a coil wire wound around the magnetic wire, and the coil wire has a load of 200 N / mm ２ A power generation sensor according to any one of claims 1 to 6, having the above tensile strength.

8. The power generation sensor according to any one of claims 1 to 7, wherein the first external electrode terminal has a first mounting surface fixed to the mounting substrate, and the second external electrode terminal has a second mounting surface fixed to the mounting substrate.

9. The power generation sensor according to claim 8, wherein the first length of the first mounting surface in a direction perpendicular to the axial direction of the magnetic wire is greater than the second length of the first mounting surface in the axial direction.

10. The power generation sensor according to claim 8, wherein the coil body includes a first end facing the first soft magnetic body portion and a second end facing the second soft magnetic body portion, and in a plan view from the axial direction of the magnetic wire, the portion of the first end opposite to the first mounting surface with respect to the magnetic wire is exposed from the first soft magnetic body portion, and in the plan view from the axial direction of the magnetic wire, the portion of the second end opposite to the second mounting surface with respect to the magnetic wire is exposed from the second soft magnetic body portion.

11. The power generation sensor according to any one of claims 1 to 10, wherein the first soft magnetic body portion is provided with a first through-hole into which the magnetic wire is inserted, and the second soft magnetic body portion is provided with a second through-hole into which the magnetic wire is inserted.

12. The power generation sensor according to any one of claims 1 to 10, wherein the first soft magnetic body portion is provided with a first groove into which the magnetic wire is inserted, and the second soft magnetic body portion is provided with a second groove into which the magnetic wire is inserted.

13. The power generation sensor according to any one of claims 1 to 12, wherein the first external electrode terminal is fitted into a first fitting groove provided in the first soft magnetic body.

14. The power generation sensor according to any one of claims 1 to 13, wherein the first soft magnetic component includes a first soft magnetic projection projecting toward the second soft magnetic body, the second soft magnetic component includes a second soft magnetic projection projecting toward the first soft magnetic body, the first soft magnetic projection and the second soft magnetic projection are separated from the coil body, and the second soft magnetic projection is separated from the first soft magnetic projection.

15. The power generation sensor according to claim 14, wherein the first width of the first soft magnetic projection and the second width of the second soft magnetic projection are greater than the diameter of the magnetic wire.

Images