Magnetoelectric conversion device

Abstract

This magnetoelectric conversion device (3) converts a magnetic field generated from an object into electricity, the device being characterized by comprising: magnetostrictive members (11, 12) that are deformed by the magnetic field; a piezoelectric member (13) that is fixed to the magnetostrictive members (11, 12) and bent by the deformation of the magnetostrictive members (11, 12); and a calculation unit (80) that receives a voltage output from the piezoelectric member (13) due to the bending of the piezoelectric member (13) and calculates the position of the object on the basis of the voltage.

Description

Magnetoelectric conversion device

[0001] The present disclosure relates to a magnetoelectric conversion device that converts a magnetic field generated from an object into electricity and utilizes the electricity.

[0002] As a magnetoelectric conversion device that converts a magnetic field generated from an object into electricity and utilizes it, a current sensor that converts a magnetic field generated from a current line into electricity and measures current has been proposed (see, for example, Patent Document 1). This current sensor includes a piezoelectric element and first and second magnetostrictive bodies laminated on the upper and lower surfaces of the piezoelectric element, and measures the current flowing in the current line based on the voltage between the electrodes of the piezoelectric element, which deforms in response to deformation of the first and second magnetostrictive bodies due to deformation of the magnetic field.

[0003] JP 2019-011989 A

[0004] However, the use of the device described in Patent Document 1 is limited to use as a current sensor, and it cannot be used for purposes such as displacement measurement or power storage.

[0005] An object of the present disclosure is to provide a magnetoelectric conversion device that can convert a magnetic field generated from an object into electricity and be used for purposes such as displacement measurement or electricity storage.

[0006] The magnetoelectric conversion device disclosed herein is a device that converts a magnetic field generated from an object into electricity, and is characterized by having a magnetostrictive member that deforms due to the magnetic field, a piezoelectric member that is fixed to the magnetostrictive member and bends due to the deformation of the magnetostrictive member, and a calculation unit that receives a voltage output from the piezoelectric member due to the bending of the piezoelectric member and calculates the position of the object based on the voltage.

[0007] Another magnetoelectric conversion device disclosed herein is a device that converts a magnetic field generated from an object into electricity and utilizes it, and is characterized by having a magnetostrictive member that deforms due to the magnetic field, a piezoelectric member that is fixed to the magnetostrictive member and bends due to the deformation of the magnetostrictive member, and a storage unit that receives the voltage output from the piezoelectric member due to the bending of the piezoelectric member and stores power based on the voltage in a storage battery.

[0008] According to the device of the present disclosure, the magnetic field generated from an object can be converted into electricity and used for purposes such as displacement measurement or electricity storage.

[0009] 1 is a schematic diagram showing the configuration of a magnetoelectric converter (power storage device) according to a first embodiment; FIG. 2 is a schematic perspective view showing the configuration of a magnetoelectric converter unit of the magnetoelectric converter according to the first embodiment; (A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric converter unit of the magnetoelectric converter according to the first embodiment; (A) and (B) are schematic cross-sectional views showing another example of the operation of the magnetoelectric converter unit of the magnetoelectric converter according to the first embodiment; FIG. 3 is a schematic diagram showing the configuration of a magnetoelectric converter (power storage device) according to a modified example of the first embodiment; (A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric converter unit of the magnetoelectric converter according to the modified example of the first embodiment; FIG. 4 is a schematic diagram showing the configuration of a magnetoelectric converter (power storage device) according to a second embodiment; (A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric converter unit of the magnetoelectric converter according to the second embodiment; FIG. 5 is a schematic diagram showing the configuration of a magnetoelectric converter (power storage device) according to a first modified example of the second embodiment; (A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric converter unit of the magnetoelectric converter according to the first modified example of the second embodiment. 1 is a schematic diagram showing the configuration of a magnetoelectric conversion device (power storage device) according to a second modification of the second embodiment. FIG. 2 is a schematic diagram showing the configuration of a magnetoelectric conversion device (power storage device) according to a third modification of the second embodiment. FIG. 3 is a schematic diagram showing the configuration of a magnetoelectric conversion device (displacement measurement device) according to a third embodiment. FIG. 4 is a schematic perspective view showing the configuration of a magnetoelectric conversion unit of the magnetoelectric conversion device according to the third embodiment. (A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit of the magnetoelectric conversion device according to the third embodiment. FIG. 5 is a schematic diagram showing the configuration of a magnetoelectric conversion device (displacement measurement device) according to a sixth embodiment. FIG. 6 is a schematic perspective view showing the configuration of a magnetoelectric conversion unit of the magnetoelectric conversion device according to the fourth embodiment. (A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit of the magnetoelectric conversion device according to the fourth embodiment. FIG. 7 is a schematic diagram showing the configuration of a magnetoelectric conversion device (displacement measurement device) according to a fifth embodiment. FIG. 8 is a schematic perspective view showing the configuration of the magnetoelectric conversion unit of the magnetoelectric conversion device according to the fifth embodiment. (A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit of the magnetoelectric conversion device according to the fifth embodiment. FIG. 9 is a schematic diagram showing the configuration of a magnetoelectric conversion device (displacement measurement device) according to a sixth embodiment. 13A and 13B are schematic perspective views showing the configuration of a magnetoelectric conversion unit of a magnetoelectric conversion device according to a sixth embodiment, and are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit of the magnetoelectric conversion device according to the sixth embodiment.10 is a schematic diagram showing the configuration of a magnetoelectric conversion device (displacement measuring device) according to embodiment 7. FIG. 11 is a schematic diagram showing the configuration of a magnetoelectric conversion device (electricity storage device) according to embodiment 8. FIG. 12 is a schematic diagram showing the configuration of a magnetoelectric conversion device (electricity storage device) according to embodiment 9.

[0010] Magnetoelectric conversion devices according to embodiments will be described below with reference to the drawings. The following embodiments are merely examples, and the embodiments can be combined as appropriate and each embodiment can be modified as appropriate. The figures show coordinate axes of an xyz Cartesian coordinate system to facilitate understanding of the relationship between the figures. The x-axis is a coordinate axis extending in the longitudinal direction of the magnetostrictive member and the piezoelectric member, the y-axis is a coordinate axis extending in the width direction (i.e., the short direction) of the magnetostrictive member and the piezoelectric member, and the z-axis is a coordinate axis extending in the thickness direction of the piezoelectric member. In addition, in each figure, the same reference numerals are used to designate components that are the same or have similar functions.

[0011] The magnetoelectric conversion device according to the embodiment is a device that converts a magnetic field generated from an object into electricity for use. An example of a magnetic field generated from an object is a magnetic field generated from a current line through which an AC current or a DC current (a period during which the current value fluctuates) flows. Another example of a magnetic field generated from an object is a magnetic field generated from a moving (including vibrating) magnet.

[0012] An example of a magnetoelectric conversion device according to an embodiment is a displacement measurement device that measures the displacement (e.g., position or distance) of an object based on electricity (e.g., voltage) converted from a magnetic field. Another example of a magnetoelectric conversion device according to an embodiment is a power storage device that stores electricity converted from a magnetic field in a storage battery.

[0013] <<First Embodiment>> Fig. 1 is a schematic diagram showing the configuration of a magnetoelectric converter 1 according to a first embodiment. Fig. 2 is a schematic perspective view showing the configuration of a magnetoelectric converter 10 of the magnetoelectric converter 1. The magnetoelectric converter 1 is a device that converts a magnetic field generated from a current line 100, which serves as an object, arranged in a position facing the underside of the magnetoelectric converter 10, into electricity and utilizes the electricity. The magnetoelectric converter 1 is an electricity storage device.

[0014] The magnetoelectric conversion device 1 includes magnetostrictive members 11 and 12 that deform in response to a magnetic field, a piezoelectric member (i.e., a piezoelectric element) 13 that is fixed to the magnetostrictive members 11 and 12 and bends as the magnetostrictive members 11 and 12 deform, and a power storage unit 60 that receives a voltage output from the piezoelectric member 13 as the piezoelectric member 13 bends and stores the power based on this voltage in a storage battery. The piezoelectric material that constitutes the piezoelectric member 13 is, for example, lead zirconate titanate (PZT). The magnetostrictive material that forms the magnetostrictive members 11 and 12 is, for example, Terfenol-D, an alloy consisting of iron (Fe), dysprosium (Dy), and terbium (Tb). The magnetostrictive members 11 and 12 are arranged to sandwich the piezoelectric member 13. The magnetostrictive members 11 and 12 are fixed to both sides of the piezoelectric member 13, for example, with an adhesive. The magnetostrictive member 11 is also referred to as the "first magnetostrictive member." The magnetostrictive member 12 is also referred to as the “second magnetostrictive member.” The magnetostrictive members 11 and 12 each have, for example, a thickness of 1.0 mm, a width in the y direction of 6 mm, and a length in the x direction of 12 mm, and the length of the piezoelectric member 13 in the x direction is 15 mm.

[0015] The magnetostrictive members 11, 12 are plate-shaped and elongated in the x-direction. The magnetostrictive members 11, 12 expand or contract in the longitudinal direction of the magnetostrictive members 11, 12 due to a magnetic field. That is, one of the magnetostrictive members 11, 12 expands in the longitudinal direction, and the other of the magnetostrictive members 11, 12 contracts in the longitudinal direction. The magnetostrictive members 11, 12 and the piezoelectric member 13 constitute the magnetoelectric conversion unit 10.

[0016] 3A and 3B are schematic cross-sectional views illustrating the operation of the magnetoelectric conversion unit 10 of the magnetoelectric conversion device 1 according to the first embodiment. FIG. 3A shows how the magnetostrictive member 11 expands (extends in the x-direction) and the magnetostrictive member 12 contracts (shrinks in the x-direction) when a magnetic field M1 in the +x-direction is applied to the magnetostrictive members 11 and 12 by a current flowing through the current line 100. At this time, the piezoelectric member 13 curves downwardly convexly (i.e., upwardly concavely). FIG. 3B shows how the magnetostrictive member 11 contracts (shrinks in the x-direction) and the magnetostrictive member 12 expands (extends in the x-direction) when a magnetic field M2 in the -x-direction is applied to the magnetostrictive members 11 and 12 by a current flowing through the current line 100. At this time, the piezoelectric member 13 curves upwardly convexly (i.e., downwardly concavely).

[0017] 4A and 4B are schematic cross-sectional views showing another example of the operation of the magnetoelectric conversion unit of the magnetoelectric conversion device 1 according to the first embodiment. FIG. 4A shows how the magnetostrictive member 11 expands (extends in the x-direction) and the magnetostrictive member 12 contracts (shrinks in the x-direction) when a magnetic field M2 in the -x-direction is applied to the magnetostrictive members 11 and 12 by a current flowing through the current line 100. At this time, the piezoelectric member 13 curves downwardly convexly (i.e., upwardly concavely). FIG. 4B shows how the magnetostrictive member 11 contracts (shrinks in the x-direction) and the magnetostrictive member 12 expands (extends in the x-direction) when a magnetic field M1 in the +x-direction is applied to the magnetostrictive members 11 and 12 by a current flowing through the current line 100. At this time, the piezoelectric member 13 curves upwardly convexly (i.e., downwardly concavely).

[0018] The power storage unit 60 includes a rectifier circuit 61 that rectifies (e.g., full-wave rectification) the AC voltage generated by repeating the operations shown in Figures 3(A) and (B) or 4(A) and (B) and a power storage circuit 62 that stores power based on the rectified AC voltage in a storage battery. The storage battery is provided inside or outside the power storage unit 60. The power storage unit 60 may include a processor that operates by software.

[0019] Fig. 5 is a schematic diagram showing the configuration of a magnetoelectric converter 1a according to a modified example of embodiment 1. Figs. 6(A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric converter 14 of the magnetoelectric converter 1a. The magnetoelectric converter 1a is a device that converts a magnetic field generated from a current line 100, which serves as an object and is arranged at a position facing the underside of the magnetoelectric converter 10a, into electricity and utilizes the electricity. The magnetoelectric converter 1a is a power storage device.

[0020] The magnetoelectric converter 1a shown in Fig. 5 differs from the magnetoelectric converter 1 shown in Fig. 1 in that the magnetoelectric converter 14 is composed of a magnetostrictive member 11 and a piezoelectric member 13 fixed thereto. As shown in Fig. 5, the magnetostrictive members 11 do not necessarily have to be provided on both sides of the piezoelectric member 13. The magnetoelectric converter may also be composed of the magnetostrictive member 12 shown in Fig. 1 and the piezoelectric member 13 fixed thereto. The magnetoelectric converter 10a composed of one magnetostrictive member and a piezoelectric member 13 is also applicable to embodiments 2 to 9 described below.

[0021] According to the magnetoelectric conversion devices 1 and 1a, it is possible to use the power stored in the storage battery to drive a Hall element (not shown) or a current sensor (not shown) for detecting the current flowing through the current line 100. Furthermore, it is possible to use the power stored in the storage battery to drive an environmental sensor (not shown) such as a temperature (humidity) sensor to monitor the environment around the current line 100, such as the temperature and humidity. Furthermore, it is possible to use the power stored in the storage battery to drive a wireless communication device such as Bluetooth (registered trademark), thereby wirelessly transmitting sensor information. In this case, it is possible to eliminate wiring from external power sources for the current sensor, environmental sensor, and wireless communication device, and also to eliminate wiring for transmitting detected data.

[0022] <<Embodiment 2>> Fig. 7 is a schematic diagram showing the configuration of a magnetoelectric converter 2 according to embodiment 2. Figs. 8(A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric converter 10 of the magnetoelectric converter 2. The magnetoelectric converter 2 is a device that converts a magnetic field generated from a current line 100, which serves as an object, arranged in a position facing the underside of the magnetoelectric converter 10, into electricity and utilizes the electricity. The magnetoelectric converter 2 is an electricity storage device.

[0023] The magnetoelectric converter 2 shown in FIG. 7 differs from the magnetoelectric converter 1 shown in FIG. 1 in that it further includes a bias magnet 20 that applies a bias magnetic field B1 that expands the magnetostrictive member 11 and contracts the magnetostrictive member 12. As shown in FIG. 7 , in the magnetoelectric converter 2, when no current flows through the current line 100, the bias magnetic field B1 causes the magnetoelectric converter 10 to curve. As shown in FIGS. 8A and 8B , even when current flows through the current line 100, the magnetoelectric converter 10 only curves downward convexly. The bias magnet 20 is, for example, an NdFeB magnet, which is a rare earth magnet. An NdFeB magnet is a magnet primarily composed of neodymium (Nd), iron (Fe), and boron (B). The bias magnet 20 has dimensions of, for example, 4 mm × 4 mm × 2 mm, and the dimension in the magnetization direction shown in FIG. 1 is, for example, 2 mm.

[0024] The bias magnet 20 applies a magnetic field in the longitudinal direction of the magnetostrictive members 11 and 12. By changing the strength of the magnetic field applied from the bias magnet 20 to the magnetoelectric conversion unit 10, the magnitude of the voltage generated in the piezoelectric member 13 is changed.

[0025] For example, the bias magnet 20 is arranged to face one end in the longitudinal direction of the magnetoelectric converting unit 10 so that the magnetization direction is parallel to the longitudinal direction of the magnetoelectric converting unit 10. Note that an electromagnet can also be used as the excitation source.

[0026] In this case, it is possible to eliminate the rectifier circuit from the power storage unit 60a, thereby simplifying the power storage unit 60a, although the power storage unit 60a may be provided with a rectifier circuit.

[0027] Fig. 9 is a schematic diagram showing the configuration of a magnetoelectric converter 2a according to a first modification of the second embodiment. Figs. 10(A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric converter 10 of the magnetoelectric converter 2a. The magnetoelectric converter 2a is a device that converts a magnetic field generated from a current line 100, which serves as an object and is arranged in a position facing the underside of the magnetoelectric converter 10, into electricity and utilizes the electricity. The magnetoelectric converter 2a is an electricity storage device. The magnetoelectric converter 2a shown in Fig. 9 differs from the magnetoelectric converter 1 shown in Fig. 1 in that it further includes a bias magnet 20a that applies a bias magnetic field B2 that contracts the magnetostrictive member 11 and expands the magnetostrictive member 12. As shown in Figure 9, in the magnetoelectric conversion device 2a, when no current flows through the current line 100, the magnetoelectric conversion unit 10 is curved by the bias magnetic field B2, and even when current flows through the current line 100, as shown in Figures 10 (A) and (B), the magnetoelectric conversion unit 10 is only curved upwardly convexly.

[0028] In this case, it is possible to eliminate the rectifier circuit from the power storage unit 60a, thereby simplifying the power storage unit 60a, although the power storage unit 60a may be provided with a rectifier circuit.

[0029] FIG. 11 is a schematic diagram showing the configuration of a magnetoelectric converter 2b according to a second modification of the second embodiment. The magnetoelectric converter 2b is a device that converts a magnetic field generated from a current line 100, which serves as an object and is positioned opposite the underside of the magnetoelectric converter 10, into electricity for use. The magnetoelectric converter 2b is an electricity storage device. The magnetoelectric converter 2b shown in FIG. 11 differs from the magnetoelectric converter 1 shown in FIG. 1 in that it further includes a bias magnet 20b that applies a bias magnetic field B1 that contracts the magnetostrictive member 12. As shown in FIG. 11, in the magnetoelectric converter 2b, when no current flows through the current line 100, the magnetoelectric converter 10 is curved by the bias magnetic field B1. Even in this case, the curvature of the magnetoelectric converter 10 can be limited to a downward convex shape, thereby simplifying the electricity storage device.

[0030] FIG. 12 is a schematic diagram showing the configuration of a magnetoelectric converter 2c according to a third modification of the second embodiment. The magnetoelectric converter 2c converts a magnetic field generated by a current line 100, which serves as an object and is positioned opposite the underside of the magnetoelectric converter 10, into electricity for use. The magnetoelectric converter 2c is an electric storage device. The magnetoelectric converter 2c shown in FIG. 12 differs from the magnetoelectric converter 1 shown in FIG. 1 in that it further includes a bias magnet 20b that applies a bias magnetic field B1 that contracts the magnetostrictive member 12 and a bias magnet 20c that applies a bias magnetic field B2 that expands the magnetostrictive member 11. As shown in FIG. 12, in the magnetoelectric converter 2c, the magnetoelectric converter 10 is curved by the bias magnetic fields B1 and B2 when no current flows through the current line 100. Even in this case, the curvature of the magnetoelectric converter 10 can be limited to a downward convex shape, simplifying the electric storage device.

[0031] The position, number, and direction of the magnetic field of the bias magnets are not limited to the above example, and various modifications are possible.

[0032] Third Embodiment Fig. 13 is a schematic diagram showing the configuration of a magnetoelectric converter 3 according to a third embodiment. Fig. 14 is a schematic perspective view showing the configuration of a magnetoelectric converter 10 of the magnetoelectric converter 3. The magnetoelectric converter 3 is a device that converts into electricity a magnetic field generated from a magnet 200, which is an object arranged in a position facing the underside of the magnetoelectric converter 10, and utilizes the electricity. The magnetoelectric converter 3 is a displacement measurement device that measures the displacement of the magnet 200 in the z direction. The displacement measurement device is a distance measurement device that measures the distance in the z direction or a position measurement device that measures the position in the z direction.

[0033] The magnetoelectric conversion device 3 includes magnetostrictive members 11 and 12 that deform in response to a magnetic field, a piezoelectric member 13 that is fixed to the magnetostrictive members 11 and 12 and bends as the magnetostrictive members 11 and 12 deform, and a calculation unit 80 that receives a voltage output from the piezoelectric member 13 due to the bending of the piezoelectric member 13 and performs calculations based on this voltage. The calculation unit 80 includes, for example, an A / D conversion circuit 81 that performs analog-to-digital (A / D) conversion of the output of the piezoelectric member 13 that bends in response to a magnetic field applied to the magnetostrictive members 11 and 12, and a calculation circuit 82 that calculates displacement in the z-direction (D1) based on the output of the A / D conversion circuit 81. The magnetostrictive members 11 and 12 are arranged to sandwich the piezoelectric member 13. The magnetostrictive members 11 and 12 are fixed to both sides of the piezoelectric member 13, for example, with an adhesive. The calculation unit 80 may include a processor operated by software.

[0034] 15A and 15B are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit 10 of the magnetoelectric conversion device 3 according to the third embodiment. FIG. 15A shows a state in which the magnet 200, which generates a magnetic field in the x-direction, is separated from the magnetoelectric conversion unit 10, and almost no magnetic field is applied to the magnetostrictive members 11 and 12 (a weak magnetic field M1 is applied). At this time, the magnetoelectric conversion unit 10 is not curved. FIG. 15B shows a state in which the magnetostrictive member 11 expands (extends in the x-direction) and the magnetostrictive member 12 contracts (shrinks in the x-direction) when the magnet 200 approaches the magnetoelectric conversion unit 10 and a stronger magnetic field M1 than that shown in FIG. 15A is applied to the magnetostrictive members 11 and 12. At this time, the magnetoelectric conversion unit 10 curves downwardly convexly (i.e., upwardly concavely).

[0035] The magnetoelectric conversion device 3 can measure the amount of displacement (i.e., distance or position) of the magnet 200 (i.e., a member including the magnet 200) in the D1 direction.

[0036] <<Fourth Embodiment>> Fig. 16 is a schematic diagram showing the configuration of a magnetoelectric converter 4 according to a fourth embodiment. Fig. 17 is a schematic perspective view showing the configuration of a magnetoelectric converter 10 of the magnetoelectric converter 4. The magnetoelectric converter 4 is a device that converts into electricity a magnetic field generated from a magnet 200, which is an object arranged in a position facing the underside of the magnetoelectric converter 10, and utilizes the electricity. The magnetoelectric converter 4 is a displacement measuring device that measures the displacement of the magnet 200 in the z direction (direction D1). The displacement measuring device is a distance measuring device that measures a distance in the z direction or a position measuring device that measures a position in the z direction.

[0037] 18(A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit 10 of the magnetoelectric conversion device 4. The magnetoelectric conversion device 4 shown in FIG. 16 differs from the magnetoelectric conversion device 3 shown in FIG. 13 in that it further includes a bias magnet 20a that applies a bias magnetic field B2. As shown in FIG. 18(A), in the magnetoelectric conversion device 4, the magnetoelectric conversion unit 10 is maintained in an unbent state by the bias magnetic field B2, and as shown in FIG. 18(B), when the magnet 200 approaches the magnetoelectric conversion unit 10, the magnetoelectric conversion unit 10 bends in a downward convex shape. Note that the bias magnet 20a desirably includes a mechanism that enables adjustment of the distance from the magnetoelectric conversion unit 10 or its position in the z direction relative to the magnetoelectric conversion unit 10.

[0038] The magnetoelectric conversion device 4 can measure the displacement (i.e., distance or position) of the magnet 200 (i.e., a member including the magnet 200) in the D1 direction. In addition, the sensitivity can be adjusted by adjusting the position of the bias magnet 20a.

[0039] Fifth Embodiment Fig. 19 is a schematic diagram showing the configuration of a magnetoelectric converter 5 according to a fifth embodiment. Fig. 20 is a schematic perspective view showing the configuration of a magnetoelectric converter 10 of the magnetoelectric converter 5. The magnetoelectric converter 5 is a device that converts a magnetic field generated from a magnet 300, which serves as an object and is arranged in a position facing the underside of the magnetoelectric converter 10, into electricity and utilizes the electricity. The magnetoelectric converter 5 is a displacement measurement device that measures the displacement of the magnet 300 in the x direction (direction D2). The displacement measurement device is a distance measurement device that measures the distance in the x direction from a reference position, or a position measurement device that measures the position in the x direction.

[0040] 21A and 21B are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit 10 of the magnetoelectric conversion device 5. The magnetoelectric conversion device 5 shown in FIG. 19 differs from the magnetoelectric conversion device 3 shown in FIG. 13 in that the magnet 300 has a portion that generates a magnetic field in the +z direction and a portion that generates a magnetic field in the opposite direction, the -z direction, and the magnet 300 moves in the D2 direction. As shown in FIG. 21A, in the magnetoelectric conversion device 5, the magnetic field M2 applied to the magnetostrictive members 11 and 12 weakens depending on the amount of displacement of the magnet 300 from the center position of the magnetoelectric conversion unit 10 in the z direction. As shown in FIG. 21B, the closer the magnet 300 is to the center position of the magnetoelectric conversion unit 10 in the z direction, the stronger the magnetic field M2 applied to the magnetostrictive members 11 and 12, causing the magnetoelectric conversion unit 10 to curve downward in a convex shape. In this way, according to the fifth embodiment, the position of an object in the z direction can be measured.

[0041] Sixth Embodiment Fig. 22 is a schematic diagram showing the configuration of a magnetoelectric converter 6 according to a sixth embodiment. Fig. 23 is a schematic perspective view showing the configuration of a magnetoelectric converter 10 of the magnetoelectric converter 6. The magnetoelectric converter 6 is a device that converts into electricity a magnetic field generated from a magnet 300, which serves as an object and is arranged in a position facing the underside of the magnetoelectric converter 10, and utilizes the electricity. The magnetoelectric converter 6 is a displacement measurement device that measures the displacement of the magnet 300 in the y direction (direction D2). The displacement measurement device is a distance measurement device that measures a distance in the x direction or a position measurement device that measures a position in the x direction.

[0042] 24(A) and (B) are schematic cross-sectional views showing the operation of the magnetoelectric conversion unit 10 of the magnetoelectric conversion device 6. The magnetoelectric conversion device 6 shown in FIG. 22 differs from the magnetoelectric conversion device 5 shown in FIG. 19 in that it further includes a bias magnet 20a that applies a bias magnetic field B2. As shown in FIG. 24(A), in the magnetoelectric conversion device 6, the magnetoelectric conversion unit 10 is maintained in an unbent state by the bias magnetic field B2, and as shown in FIG. 24(B), when the magnet 300 approaches the end of the magnetoelectric conversion unit 10, the magnetoelectric conversion unit 10 bends in an upward convex shape. Note that the bias magnet 20a desirably includes a mechanism that allows adjustment of the distance from the magnetoelectric conversion unit 10 or its position in the z direction relative to the magnetoelectric conversion unit 10.

[0043] The magnetoelectric conversion device 6 can measure the displacement (i.e., distance or position) of the magnet 300 (i.e., a member equipped with the magnet 300) in the D2 direction. In addition, the sensitivity can be adjusted by adjusting the position of the bias magnet 20a.

[0044] Seventh Embodiment FIG. 25 is a schematic diagram showing the configuration of a magnetoelectric converter 7 according to a seventh embodiment. The magnetoelectric converter 7 converts the magnetic field generated by a magnet 300a (a target object) positioned opposite the underside of the magnetoelectric converter 10 into electricity for use. The magnetoelectric converter 7 is a displacement measurement device that measures the displacement of the magnet 300a in the x direction (direction D2). The displacement measurement device is, for example, a linear encoder. In the magnetoelectric converter 7 shown in FIG. 25, the magnet 300a has alternating portions that generate a magnetic field in the +z direction and portions that generate a magnetic field in the opposite direction, the -z direction, and the magnet 300a moves in the D2 direction. The number of magnetic portions constituting the magnet 300a is not limited to four and may be five or more. Thus, according to the seventh embodiment, the position of the target object in the z direction can be measured based on the number of pulse signals, which are encoder signals, output from the piezoelectric element 13, thereby simplifying the configuration of the calculation unit 80.

[0045] 26 is a schematic diagram showing the configuration of a magnetoelectric converter 8 according to embodiment 8. The magnetoelectric converter 8 is a device that converts into electricity a magnetic field generated from a magnet 200, which is an object disposed in a position facing the underside of the magnetoelectric converter 10. The magnetoelectric converter 8 is a power storage device having a power storage unit 60b.

[0046] 26 differs from the magnetoelectric converter 2 according to the second embodiment (FIG. 7) in that it further includes a pickup coil 30 that is disposed so as to surround the magnetostrictive members 11, 12 and through which an induced current flows due to deformation of the magnetostrictive members 11, 12, and in that a power storage unit 60b also stores power based on the induced current in the pickup coil 30 in the storage battery. That is, in the magnetoelectric converter 8, the power storage unit 60b not only charges the storage battery with power based on the voltage generated by the bending of the piezoelectric member 13, but also stores power based on the induced current that flows in the pickup coil 30 due to displacement of the magnet 200 (for example, vibration in the D1 direction). Note that the magnet 200 may be a magnet that displaces in the x direction (direction D2) relative to the magnetoelectric converter 10.

[0047] With this configuration, for example, it is possible to improve the electricity storage performance for mechanical energy.

[0048] As in the first embodiment, the power stored in the storage battery in the power storage unit 60b can be used to drive an environmental sensor (not shown), such as a temperature (humidity) sensor, to monitor the environment, such as the temperature and humidity, around the current line 100, and the power stored in the storage battery can be used to drive a wireless communication device, thereby transmitting sensor information wirelessly. In this case, it is possible to eliminate wiring from the external power source for the current sensor, the environmental sensor, and the wireless communication device, and also to eliminate wiring for transmitting detected data.

[0049] 27 is a schematic diagram showing the configuration of a magnetoelectric converter 9 according to embodiment 9. The magnetoelectric converter 9 is a device that converts into electricity a magnetic field generated from a bias magnet 20, which serves as an object and is arranged at a position facing an end of the magnetoelectric converter 10. The magnetoelectric converter 9 is a power storage device that has a power storage unit 60b.

[0050] The magnetoelectric conversion device 9 includes a leaf spring 41 that supports the bias magnet 20 and the magnetoelectric conversion unit 10, and a weight 42 fixed to the leaf spring 41. The leaf spring 41 is supported by a vibrating device 40 that applies vibrations to the bias magnet 20 and the magnetoelectric conversion unit 10 via the leaf spring 41. Electric power generated by changes in the relative positions of the bias magnet 20 and the magnetoelectric conversion unit 10 with respect to the pickup coil 30 is stored in the power storage unit 60b. The structure of the leaf spring 41 is not limited to the illustrated example, and may be any other structure that generates changes in the relative positions of the bias magnet 20 and the magnetoelectric conversion unit 10 with respect to the pickup coil 30 (i.e., changes in the magnetic flux penetrating the pickup coil 30). The weight 42 is not an essential component. Examples of the device 40 include micro-vibrators such as machinery in a factory that generates vibrations, structures such as bridges that vibrate due to vehicle movement, and floors that vibrate due to foot traffic, as well as reciprocating structures such as the work shaft of a machine tool and opening / closing windows and doors.

[0051] The leaf spring 41 may be an elastic body having another shape, such as a U-shaped spring or a coil spring.

[0052] With this configuration, for example, it is possible to improve the electrical storage performance for mechanical energy. Also, similar to the eighth embodiment, it is possible to eliminate wiring from the power source and wiring for transmitting detected data.

[0053] 1, 1a, 2, 2a to 2c, 8, 9 Magnetoelectric conversion device (power storage device), 3 to 7 Magnetoelectric conversion device (displacement measuring device), 11, 12 Magnetostrictive member, 13 Piezoelectric member, 20, 20a, 20b Bias magnet, 30 Pickup coil, 40 Equipment, 60, 60a, 60b Power storage unit, 61 Rectifier circuit, 62 Power storage circuit, 80 Calculation unit, 81 A / D conversion circuit, 82 Calculation circuit, 100 Current line, 200 Magnet, 300, 300a Magnet.

Claims

1. A magnetoelectric conversion device that converts a magnetic field generated from an object into electricity, a magnetostrictive member that is deformed by the magnetic field; a piezoelectric member fixed to the magnetostrictive member and curved by deformation of the magnetostrictive member; a calculation unit that receives a voltage output from the piezoelectric member due to bending of the piezoelectric member, and calculates a position of the object based on the voltage; having The magnetostrictive member and the piezoelectric member are laminated, A magnetoelectric conversion device, characterized in that the object is disposed in a stacking direction of the magnetostrictive member and the piezoelectric member.

2. The magnetostrictive member is a long plate-like member, The magnetostrictive member expands or contracts in the longitudinal direction of the magnetostrictive member due to the magnetic field.

2. A magnetoelectric conversion device according to claim 1.

3. The magnetostrictive member includes a first magnetostrictive member and a second magnetostrictive member disposed so as to sandwich the piezoelectric member, The first magnetostrictive member and the second magnetostrictive member are long and plate-like, With respect to the same magnetic field direction, one of the first magnetostrictive member and the second magnetostrictive member expands in the longitudinal direction of the magnetostrictive member, and the other of the first magnetostrictive member and the second magnetostrictive member contracts in the longitudinal direction.

2. A magnetoelectric conversion device according to claim 1.

4. the object includes a magnet; The calculation unit outputs a signal having a value corresponding to the distance from the magnet to the magnetostrictive member.

4. A magnetoelectric conversion device according to claim 1, wherein the magnetoelectric conversion device is a magnetoelectric conversion device.

5. the object includes a magnet; The calculation unit outputs a signal having a value corresponding to the position of the magnetostrictive member in the longitudinal direction relative to the magnetostrictive member.

4. A magnetoelectric conversion device according to claim 2 or 3.

6. The target object includes a plurality of magnets arranged side by side in a longitudinal direction of the magnetostrictive member, The calculation unit outputs an encoder signal having a value corresponding to a position in the longitudinal direction with respect to the magnetostrictive member.

4. A magnetoelectric conversion device according to claim 2 or 3.

7. The magnetostrictive member further includes a bias magnet that applies a bias magnetic field to the magnetostrictive member to expand or contract the magnetostrictive member.

4. A magnetoelectric conversion device according to claim 1, wherein the magnetoelectric conversion device is a magnetoelectric conversion device.

8. The magnetostrictive member further includes a bias magnet that causes one of the first magnetostrictive member and the second magnetostrictive member to expand in the longitudinal direction and causes the other of the first magnetostrictive member and the second magnetostrictive member to contract in the longitudinal direction.

4. The magnetoelectric conversion device according to claim 3.

9. A magnetoelectric conversion device that converts a magnetic field generated from an object into electricity and utilizes it, a magnetostrictive member that is deformed by the magnetic field; a piezoelectric member fixed to the magnetostrictive member and curved by deformation of the magnetostrictive member; a power storage unit that receives a voltage output from the piezoelectric member due to bending of the piezoelectric member and stores power based on the voltage in a storage battery; having The magnetostrictive member and the piezoelectric member are laminated, A magnetoelectric conversion device, characterized in that the object is disposed in a stacking direction of the magnetostrictive member and the piezoelectric member.

10. The magnetostrictive member is a long plate-like member, The magnetostrictive member expands or contracts in the longitudinal direction of the magnetostrictive member due to the magnetic field.

10. A magnetoelectric conversion device according to claim 9.

11. The magnetostrictive member includes a first magnetostrictive member and a second magnetostrictive member disposed so as to sandwich the piezoelectric member, The first magnetostrictive member and the second magnetostrictive member are long and plate-like, With respect to the same magnetic field direction, one of the first magnetostrictive member and the second magnetostrictive member expands in the longitudinal direction of the magnetostrictive member, and the other of the first magnetostrictive member and the second magnetostrictive member contracts in the longitudinal direction.

10. A magnetoelectric conversion device according to claim 9.

12. The magnetostrictive member further includes a bias magnet that applies a bias magnetic field to the magnetostrictive member to expand or contract the magnetostrictive member.

12. The magnetoelectric conversion device according to claim 9, wherein the magnetoelectric conversion device is a magnetoelectric conversion device.

13. The magnetostrictive member further includes a bias magnet that causes one of the first magnetostrictive member and the second magnetostrictive member to expand in the longitudinal direction and causes the other of the first magnetostrictive member and the second magnetostrictive member to contract in the longitudinal direction.

12. A magnetoelectric conversion device according to claim 11.

14. The power storage unit includes a power storage circuit that stores power based on the voltage in the storage battery.

13. A magnetoelectric conversion device according to claim 12.

15. The power storage unit includes a rectifier circuit that rectifies the voltage output from the piezoelectric member, and a power storage circuit that stores power based on the rectified voltage in the storage battery.

14. The magnetoelectric conversion device according to claim 9, wherein the magnetoelectric conversion device is a magnetoelectric conversion device.

16. The magnetostrictive member further includes a pickup coil arranged to surround the magnetostrictive member, through which an induced current flows due to deformation of the magnetostrictive member. The power storage unit stores power based on the induced current in the storage battery.

14. The magnetoelectric conversion device according to claim 9, wherein the magnetoelectric conversion device is a magnetoelectric conversion device.

17. The object includes a current line or a magnet, The magnetostrictive member expands or contracts due to the current flowing through the current line or the displacement of the magnet.

14. The magnetoelectric conversion device according to claim 9, wherein the magnetoelectric conversion device is a magnetoelectric conversion device.

18. the object includes a magnet; The magnet is supported by a vibrating device.

17. A magnetoelectric conversion device according to claim 16.