JP2018029452A - Wearable device and non-contact power transmission/reception device - Google Patents

Abstract

An object of the present invention is to provide a wearable device suitable for miniaturization and a non-contact power transmission / reception device including the wearable device, which reduces adverse effects caused by magnetic flux intrusion from the power transmission device to the wearable device. A wearable device 30 is a device capable of receiving electric power in a non-contact manner from a power transmission device 50 having a protrusion 52 and a primary antenna portion 56. The wearable device 30 includes a housing 31, a secondary antenna unit 36, and a conductor 35. The casing 31 has an air core portion 32 that penetrates, and a protruding portion 52 of the power transmission device 50 is configured to be insertable into the air core portion 32. The secondary antenna portion 36 is accommodated in the housing 31 coaxially with the air core portion 32 of the housing 31. The conductor 35 is provided in the casing 31. [Selection] Figure 2

Description

  The present invention relates to a wearable device and a technology of a contactless power transmission / reception device including the wearable device.

  The non-contact power transmission device described in Patent Document 1 includes a primary coil having an air core part and a primary side housing incorporating a primary side soft magnetic material, a secondary coil having an air core part, and 2. And a secondary casing containing the secondary soft magnetic body. The primary coil and the secondary coil are planar coils. The primary-side soft magnetic body has a protruding portion that penetrates the air core portion of the primary coil, and the primary-side housing has a corresponding convex portion. The secondary housing has a recess, and power is transmitted from the primary side to the secondary side in a state where the housings are integrated so that the convex portion of the primary housing is fitted ( For example, refer to claim 1 of patent document 1, paragraph [0018] of the specification, FIG. 1).

JP 2010-123729 A

  In recent years, wearable devices that employ a non-contact power transmission method are increasing. For example, there are bracelet and ring-shaped devices as wearable devices. Even if an antenna device for non-contact power transmission using a planar coil wound on a flat surface used for smartphones, etc. is applied to such wearable devices, there are few reasons for flat surfaces and the expectation of weight reduction Therefore, various ideas are required. In particular, the secondary device may be electrically adversely affected by the intrusion of magnetic flux from the power transmission device that occurs during power reception.

  An object of the present invention is to provide a wearable device suitable for downsizing and a non-contact power transmission / reception device including the same, which reduces adverse effects due to magnetic flux intrusion from the power transmission device to the wearable device.

In order to achieve the above object, a wearable device according to an embodiment of the present invention is a device that can receive power in a non-contact manner from a power transmission device having a protrusion and a primary antenna unit. The wearable device includes a housing, a secondary antenna unit, and a conductor.
The casing has an air core portion that penetrates, and the protrusion of the power transmission device is configured to be insertable into the air core portion.
The secondary antenna part is accommodated in the casing coaxially with the air core part of the casing.
The conductor is provided in the housing.

  The secondary antenna part is accommodated in the housing concentrically with the air core part that penetrates the housing. Therefore, a wearable device suitable for miniaturization provided with an air core part can be realized. In addition, a conductor is provided in the housing. For this reason, the penetration | invasion of the magnetic flux into a housing | casing can be suppressed and it can suppress that a bad influence is exerted on elements other than the secondary antenna part in a housing. Moreover, the designability and mechanical strength of a housing can be improved by providing a conductor.

The primary antenna portion of the power transmission device is mounted on the first magnetic plate, a magnetic body provided so as to protrude from the first magnetic plate in a direction in which the protruding portion protrudes, and the first magnetic plate. And a primary coil provided around the magnetic body. In this case, the secondary antenna unit includes a second magnetic plate having an air core portion that faces the first magnetic plate in the axial direction in a state where the protrusion is inserted into the air core portion of the housing. And a secondary coil mounted on the second magnetic plate.
By providing the magnetic body, the first magnetic plate, and the second magnetic plate, the coupling coefficient can be increased.

The housing may have an inner peripheral surface, and the conductor may be provided on at least a part of the inner peripheral surface.
Thereby, for example, when the power transmission device has a magnetic body in the protrusion, it is possible to suppress the intrusion of the magnetic flux leaking from the magnetic body into the housing, and to avoid adverse effects on elements other than the secondary antenna section in the housing.

The housing may further include an outer peripheral surface, and the conductor may be further provided on at least a part of the outer peripheral surface.
Thereby, the magnetic flux in a housing | casing can be reduced further and the designability of the outer peripheral surface of a wearable apparatus can also be improved.

  The conductor may include a first conductor provided on at least a part of the inner peripheral surface and a second conductor provided on at least a part of the outer peripheral surface.

The housing may have a first end surface and a second end surface. The first end surface is provided between the inner peripheral surface and the outer peripheral surface. The second end surface is provided between the inner peripheral surface and the outer peripheral surface, on the opposite side of the first end surface, and on the side closer to the secondary antenna unit than the first end surface. .
The conductor may be provided continuously from the inner peripheral surface to the outer peripheral surface via the first end surface.

The conductor may have a conductor end portion that is an end portion on a side close to the secondary antenna portion.
The wearable device may further include a battery disposed in a position farther from the secondary antenna portion in the axial direction than the position of the conductor end portion in the casing.
Thereby, the heat_generation | fever of a battery by the penetration | invasion of magnetic flux can be suppressed.

  The conductor may be a non-magnetic material or a magnetic material.

  A non-contact power transmission and reception device according to one aspect of the present invention includes the above-described power transmission device and the above-described wearable device.

  As mentioned above, according to this invention, the bad influence by the penetration | invasion of the magnetic flux from a power transmission apparatus to a wearable apparatus can be reduced, and the wearable apparatus suitable for size reduction can be implement | achieved.

FIG. 1A is a perspective view showing an antenna apparatus according to a reference example for understanding the technology of a non-contact power transmission / reception apparatus according to an embodiment of the present invention to be described later. 1B is a cross-sectional view taken along line AA ′ in FIG. 1A. It is a perspective view which shows the non-contact electric power transmission / reception apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is a side view of the power transmission / reception apparatus shown in FIG. 2 and shows a state where a wearable device is mounted on the power transmission device. FIG. 4 is a cross-sectional view of the power transmission and reception device shown in FIG. 3 and shows the right half from the central axis. FIG. 5 is a side view showing the wearable device according to the second embodiment. 6 is a cross-sectional view of a surface including the axial direction (z direction) of the wearable device shown in FIG. 7A to 7D show analysis results by simulation of the magnetic coupling state in each power transmitting and receiving device. FIG. 8 is a table showing coupling coefficients for Comparative Examples 1 and 2 and Embodiments 1 and 2. FIG. 9 is a perspective view showing a power transmission / reception device according to another embodiment (Comparative Example 3) of the present invention. FIG. 10 is a side view of the power transmission / reception device shown in FIG. 9. 11 is a plan view of the power transmission / reception device shown in FIG. FIG. 12 shows a part of the opposing primary antenna unit and secondary antenna unit in the power transmitting and receiving apparatus shown in FIG. 13 is a cross-sectional view showing a part (right half from the axis) of the power transmission / reception device in a state where the wearable device shown in FIG. 9 is mounted on the power transmission device. FIG. 14 is a cross-sectional view showing a power transmission / reception device according to still another embodiment (Comparative Example 4). FIG. 15 is a table showing the analysis results including the coupling coefficient by simulation for Comparative Examples 3 and 4.

  1. Reference example

  FIG. 1A is a perspective view showing an antenna apparatus according to a reference example for understanding the technology of a non-contact power transmission / reception apparatus according to an embodiment of the present invention to be described later. In the antenna device 1, as described above, the shape of the coil 10 of the antenna is designed to be a substantially rectangular shape having a size equivalent to a battery mounted on an electronic device such as a smartphone as shown in FIG. ing. Thereby, an inductance can be raised.

  1B is a cross-sectional view taken along line AA ′ in FIG. 1A. In the antenna device 1, a coil 10 is wound around a magnetic plate 13 along a main surface 13 a of the magnetic plate 13.

  However, it is difficult to incorporate such an antenna having a general planar coil as a wearable device into a small device having a through hole such as a bracelet or a ring. For example, in that case, it is necessary to accommodate the planar coil in the housing so that the planar coil is placed on the curved surface of the casing of the small device, that is, the planar portion is bent. Even in such a case, a sufficient area cannot be secured on the surface of the antenna. Therefore, in order to obtain a certain inductance, it is necessary to increase the number of turns of the coil using a thin wire. As a result, when a large amount of electric power is sent from the primary device to the wearable device, the resistance value increases and a problem of heat generation occurs. Therefore, a large amount of power cannot be supplied.

  2. Embodiment according to the present invention

  2.1) Embodiment 1

  FIG. 2 is a perspective view showing the non-contact power transmission / reception device according to the first embodiment of the present invention. Hereinafter, the non-contact power transmission / reception device is abbreviated as “power transmission / reception device”. The power transmission / reception device 100A is a device that transmits and receives power using a non-contact method, specifically, an electromagnetic coupling method (mutual induction method).

  The power transmission / reception device 100A includes a power transmission device 50 that is a primary device and a wearable device 30 that is a secondary device, that is, a power reception device. The wearable device 30 is typically a ring-type device, but can also be applied to a bracelet.

  FIG. 3 is a side view of the power transmission / reception device 100A shown in FIG. 2 and shows a state where the wearable device 30 is mounted on the power transmission device 50, that is, a state where power transmission / reception (charging in this embodiment) is possible. FIG. 4 is a cross-sectional view of the power transmission / reception device 100A shown in FIG. 3, showing the right half from the central axis along the z direction.

  The power transmission device 50 mainly includes a base housing 51, a protrusion 52, a primary antenna unit 56, and a magnetic body 57. These members are, for example, configured in a circular shape when viewed in the axial direction (the z direction which is the vertical direction in FIGS. In the base housing 51, circuit equipment including a power supply unit (not shown) for power transmission is accommodated, and the circuit equipment is electrically connected to the primary antenna unit 56. As shown in FIG. 4, the primary antenna unit 56 is disposed so as to face an opening 51 a (see FIG. 4) provided on the upper surface of the base housing 51.

  As shown in FIG. 4, the protrusion 52 has a hollow structure and is provided on the upper surface of the base housing 51 so as to cover the opening 51 a of the base housing 51. The base housing 51 and the protrusion 52 are made of resin. The protrusion 52 is inserted into the air core portion 32 that penetrates in the axial direction provided in the housing 31 of the wearable device 30, and the wearable device 30 is positioned with respect to the power transmission device 50, so that charging is possible. (See FIGS. 3 and 4).

  The primary antenna unit 56 includes a magnetic plate 54 and a primary coil 53 provided on the magnetic plate 54. The primary coil 53 is, for example, a spiral coil that is wound around the periphery of the magnetic plate 54 around the z axis. The primary coil 53 is configured by a single wire, a parallel wire, or a stranded wire.

  The size of the magnetic plate 54, that is, the diameter thereof may be larger than that shown in the figure. In that case, the primary coil 53 may not be arranged near the peripheral edge.

  As the material of the magnetic plate 54, for example, ferrite, metal magnetic material, or a mixture of magnetic particles and resin is used.

  The primary coil 53 is provided around the magnetic body 57 coaxially therewith. The magnetic body 57 is mounted on the magnetic plate 54 so as to protrude from the magnetic plate 54 in the protruding direction of the protruding portion 52 (upward direction along the z axis). The magnetic body 57, the primary antenna unit 56, and the secondary antenna unit 36 built in the wearable device 30 constitute a magnetic circuit. For this reason, in a state where the wearable device 30 is mounted on the power transmission device 50, the magnetic body 57 and the wearable so that the height position of the upper surface of the magnetic body 57 is positioned in the vicinity of the height position of the secondary antenna unit 36. The size and arrangement of the device 30 are designed. Thereby, the magnetic coupling between the primary antenna part 56 and the secondary antenna part 36 can be strengthened.

  The height of the protrusion 52 is arbitrarily set. For example, it is set to such a height that the wearable device 30 is stably placed on the power transmission device 50.

  The wearable device 30 mainly includes a housing 31, a secondary antenna unit 36, a conductor 35 provided in the housing 31, and the like. These are configured in an annular shape, and are typically configured in a circular shape when viewed in the axial direction.

  The housing 31 has the air core part 32 penetrating in the axial direction as described above. The housing 31 is made of a non-magnetic material, and particularly made of resin. As shown in FIG. 4, for example, a battery 27 and a circuit device 29 are accommodated in the housing 31. The battery 27 is also formed in an annular shape, for example, a circular shape or an arc shape along the shape of the housing 31. The circuit device 29 is disposed between the battery 27 and the secondary antenna unit 36, for example.

  The secondary antenna unit 36 is accommodated in the housing 31 coaxially with the air core 32 of the housing 31. The secondary coil 33 is electrically connected to the circuit device 29. The secondary antenna unit 36 includes a magnetic plate 34 and a secondary coil 33 provided on the magnetic plate 34. The secondary coil 33 is a spiral coil configured by being wound around the z-axis on the magnetic plate 34. The secondary coil 33 only needs to have the same configuration as the primary coil 53.

  The secondary antenna unit 36 is disposed at the end in the axial direction in the housing 31 so that the secondary coil 33 faces the primary coil 53 side in a state where the wearable device 30 is mounted on the power transmission device 50 and can be charged. Is done.

  In a state where the wearable device 30 is mounted on the power transmission device 50, the protrusion 52, the magnetic body 57, the primary antenna unit 56, and the secondary antenna unit 36 are arranged substantially coaxially.

  As the material of the magnetic plate 34, the same material as that of the magnetic plate 54 is used.

  As shown in FIG. 4, as the conductor 35, a first conductor 351 is provided in a ring shape along the inner peripheral surface 31 a of the housing 31, for example. Further, the second conductor 352 is provided in an annular shape along the outer peripheral surface 31 b of the housing 31.

  The conductor 35 is provided so as to reduce the magnetic flux especially toward the battery 27 in the housing 31. Specifically, the battery 27 is accommodated in the housing 31 so as to be disposed at a position farther in the axial direction than the position of the conductor end 35 a that is the end of the conductor 35. When there is no conductor 35, eddy current is generated by the penetration of magnetic flux into the battery 27 and the battery 27 generates heat. In this embodiment, the heat generation can be suppressed.

  The conductor 35 is a magnetic material or a non-magnetic material. The material of the conductor 35 may be a metal such as Ag, Au, Ti, SUS or the like, an amorphous magnetic body based on Fe or Co, or a conductive paint. By providing the conductor 35 on the surface of the casing 31, an eddy current is generated in the conductor 35 by the magnetic flux generated by the primary antenna unit 56. Thereby, although the coupling coefficient of the primary antenna part 56 and the secondary antenna part 36 may fall a little, the penetration | invasion of the magnetic flux in the housing | casing 31 is suppressed, ie, the magnetic flux in the housing | casing 31 can be reduced. it can.

  Further, by providing the conductor 35 made of the above-described material, it is possible to improve the decoration and design of the wearable device 30. In particular, when the wearable device 30 is a ring-type device, the decorativeness and design are important factors.

  Further, when the conductor 35 is a high-strength metal, the mechanical strength of the casing 31 made of, for example, resin can be increased. Here, if the casing 31 is entirely made of metal, an eddy current is generated in the entire casing and the coupling coefficient is further reduced. Therefore, this embodiment in which the base of the casing 31 is made of resin and the conductor 35 is partially provided is a desirable form.

  When the conductor 35 is not provided, not only the battery 27 but also the circuit device 29 may be adversely affected. For example, noise may occur in a signal generated by the circuit device 29 due to the penetration of magnetic flux. In FIG. 4, such a problem can be avoided by designing the conductor 35 to extend further downward.

  The frequency of the signal used for the circuit device 29 is often sufficiently higher than the frequency of the magnetic flux change used for power transmission. Therefore, even if the magnetic flux enters the circuit device 29, there is little possibility that a serious problem occurs in the signal of the circuit device 29. Therefore, the conductor 35 only needs to reduce at least magnetic flux intrusion into the battery 27.

  As described above, in the power transmission / reception device 100 </ b> A according to the present embodiment, the secondary antenna unit 36 is accommodated in the housing 31 concentrically with the air core 32 that penetrates the housing 31. Therefore, it is possible to realize a wearable device 30 suitable for downsizing that includes the air core portion 32. Moreover, since the conductor 35 is provided in the housing | casing 31, while the penetration | invasion of the magnetic flux into the housing | casing 31 can be suppressed, the designability and mechanical strength of the wearable apparatus 30 improve.

  When the wearable device 30 is a small device such as a ring type, the space in the housing 31 is very narrow. Therefore, it is important in the present technology to design the relative arrangement and the size (size) of the secondary antenna unit 36, the circuit device 29, the battery 27, and the conductor 35 from the viewpoint of the coupling coefficient. In particular, when the conductor is a non-magnetic material, there is a demerit that reduces the coupling coefficient as described above. However, the magnetic body 57 is provided on the power transmission device 50 side, and the coupling of the magnetic body 57 is appropriately performed (the positioning accuracy is increased) by appropriately positioning the primary antenna unit 56 and the secondary antenna unit 36. The coefficient can be improved.

  In the present embodiment, the conductor 35 is provided on both the inner peripheral surface and the outer peripheral surface of the casing 31, and the magnetic body 57 is provided, whereby the magnetic flux can be effectively reduced.

  In the present embodiment, since the protruding portion 52 is inserted into the air core portion 32 of the housing 31, the power transmission device 50 and the wearable device 30 can be easily positioned during charging. Moreover, since the primary coil 53 and the secondary coil 33 are solenoid coils, the relative positions in the circumferential direction of the power transmission device 50 and the wearable device 30 may be arbitrary during charging. Thereby, stable power transmission and reception can be performed.

  2.2) Embodiment 2

  Next, a wearable device according to Embodiment 2 of the present invention will be described. In the following description, elements that are substantially the same as members and functions included in the power transmitting and receiving apparatus 100A and the wearable device 30 according to the first embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted. The explanation will focus on the different points.

  FIG. 5 is a side view showing the wearable device according to the second embodiment. In FIG. 5, illustration of components in the casing 31 is omitted. FIG. 6 is a cross-sectional view of the surface including the z-axis of the wearable device 80 shown in FIG.

  The housing 31 has an end surface (first end surface 31c) provided between the inner peripheral surface 31a and the outer peripheral surface 31b of the housing 31, and an end surface (second end surface 31d) provided on the opposite side thereof. . The second end surface 31d facing the first end surface 31c is a surface on which the secondary antenna unit 36 is provided, that is, a surface provided on the side closer to the secondary antenna unit 36 than the first end surface 31c.

  The conductor 85 is continuously provided from the inner peripheral surface 31a to the outer peripheral surface 31b via the first end surface 31c. Thereby, compared with the wearable apparatus 30 which concerns on the said Embodiment 1, the penetration | invasion of the magnetic flux in the housing | casing 31 can be suppressed effectively. Moreover, according to the present embodiment, a design different from the design of the wearable device 30 according to the first embodiment can be realized. In addition, the mechanical strength of the housing 31 increases as the area of the conductor 85 increases as compared to the first embodiment.

  Also in the present embodiment, as in the first embodiment, it is desirable that the battery 27 is disposed near the upper part in the housing 31.

  3. Analysis of coupling state of power transmission / reception devices according to first and second embodiments

  The inventor performed an electromagnetic field simulation in order to examine the magnetic coupling state in the power transmitting / receiving device 100A according to the first embodiment and the power transmitting / receiving device according to the second embodiment (referred to as 100B). 7A to 7D show analysis results by the simulation and show magnetic flux distributions. As a simulator, “Maxwell” manufactured by Ansys was used. The inner diameter of the casing 31 of the wearable devices 30 and 80 was set to 20 mm, and the outer diameter was set to 28 mm. The cross-sectional diameters of the primary coil 53 and the secondary coil 33 were both set to 0.22 mm, and the number of turns was set to 20T. The thicknesses of the magnetic plates 34 and 54 were both set to 0.2 mm, and the magnetic permeability (relative magnetic permeability) was set to 120 and 300, respectively. The magnetic permeability of the magnetic body 57 was set to 300.

  FIG. 7A shows a simulation of a power transmission / reception device configured as a comparative example 1 including a power transmission device 150 that does not have the magnetic body 57 and a wearable device 130 that does not have the conductor 35. FIG. 7B shows a simulation of a power transmission / reception device that includes the power transmission device 150 that does not have the magnetic body 57 and the wearable device 80 according to the first embodiment as Comparative Example 2. 7C and 7D show power transmission / reception devices 100A and 100B according to the first and second embodiments, respectively.

  FIG. 8 is a table showing coupling coefficients for Comparative Examples 1 and 2 and Embodiments 1 and 2.

  In Comparative Example 1, the coupling coefficient is as high as 0.646, but the magnetic flux penetrates almost the entire case 31. In this case, the battery 27 may be adversely affected.

  In Comparative Example 2, since the conductor 35 is provided, a good result is obtained in that the penetration of the magnetic flux into the housing 31 is suppressed. However, the coupling coefficient is as small as 0.600, which is inferior to Embodiments 1 and 2 even when viewed comprehensively.

  In Embodiments 1 and 2, penetration of magnetic flux is suppressed by the conductor 35, and the coupling coefficient is as high as 0.644.

  4). Other embodiment (comparative example)

  4.1) Comparative Example 3

  FIG. 9 is a perspective view showing a power transmission / reception device according to another embodiment (Comparative Example 3) of the present invention. 10 is a side view showing power transmission / reception device 200A shown in FIG. 9, and FIG. 11 is a plan view thereof.

  In the power transmission / reception devices 100A and 100B according to the first and second embodiments, the primary antenna unit 56 and the secondary antenna unit 36 face each other in the axial direction (z direction). In the power transmission / reception device 200A according to the comparative example 3, the primary antenna unit 256 and the secondary antenna unit 236 face each other in a direction orthogonal to the axial direction.

  For example, the power transmission device 250 includes a protruding portion 252 and a primary antenna portion 256 disposed in the protruding portion 252. The wearable device 230 includes a housing 231 having an air core portion 232 that penetrates, and a secondary antenna unit 236 arranged in the housing 231. The primary antenna unit 256 includes a magnetic body 257 that protrudes in the axial direction within the protrusion 252, and a primary coil 253 provided on the side peripheral surface of the magnetic body 257. The secondary antenna unit 236 includes a magnetic plate 234 and a secondary coil 233 provided on the inner peripheral surface of the magnetic plate 234.

  The wearable device 230 is mounted on the power transmission device 250, and power can be transmitted and received (charged) in a state where the protrusion 252 is inserted into the air core portion 232 of the housing 231. In this state, the projecting portion 252, the primary antenna portion 256, and the secondary antenna portion 236 are disposed substantially coaxially, and the primary antenna portion 256 and the secondary antenna portion 236 are orthogonal to the axial direction. Opposite in the direction (radial direction). FIG. 12 shows a part of the primary antenna unit 256 and the secondary antenna unit 236 that face each other in this way. FIG. 13 is a cross-sectional view showing a part (right half from the axis) of power transmission / reception device 100 </ b> A in a state where wearable device 230 is mounted on power transmission device 250.

  Each member configuring the power transmission / reception device 200A according to the comparative example 3 includes each member corresponding to the power transmission / reception device 100A (100B) according to the first embodiment (or 2).

  In Comparative Example 3, since the protruding portion 252 of the power transmission device 250 is inserted into the air core portion 32 of the housing 231 of the wearable device 230, the positioning of both during charging becomes easy. Moreover, since the primary coil 253 and the secondary coil 233 are solenoid coils, the relative positions in the circumferential direction of the power transmission device 250 and the wearable device 230 may be arbitrary during charging. Thereby, stable power transmission and reception can be performed.

  A battery 227 and other circuit devices (not shown) are accommodated in the housing 231 of the wearable device 230. The battery 227 that may be adversely affected by the penetration of the magnetic flux is disposed on the outer peripheral side, which is a position facing the secondary coil 233 provided on the inner peripheral side of the housing 231. In this example, since the magnetic circuit is formed by the primary antenna unit 256 and the secondary antenna unit 236, there is little risk of magnetic flux entering the battery 227 disposed on the outer peripheral side.

  For example, the magnetic flux density formed by the secondary antenna unit 236 can be increased by using a ferromagnetic material as the material of the magnetic plate 234 of the secondary antenna unit 236. Thereby, the penetration | invasion of the magnetic flux to the battery 227 can be suppressed effectively. Examples of the ferromagnetic material include ferrite, metal magnetic material, or a mixture of magnetic particles and resin.

  4.2) Comparative Example 4

  FIG. 14 is a cross-sectional view showing a power transmission / reception device according to still another embodiment (Comparative Example 4). The power transmission / reception device 200B according to the comparative example 4 is different from the power transmission / reception device 200A according to the comparative example 3 in that the primary antenna unit 259 includes a magnetic plate 254. The magnetic plate 254 is magnetically connected to the magnetic body 257 and has a diameter larger than that of the magnetic body 257. For example, the magnetic plate 254 is provided coaxially with the magnetic body 257. The position of the peripheral part of the magnetic plate 254 in the radial direction is arranged at a position near the secondary antenna part 236, for example.

  According to such a configuration, the magnetic circuit is efficiently formed, and the coupling coefficient can be increased as described below as compared with Comparative Example 3 described above.

  5. Analysis of coupling state of power transmission / reception devices according to comparative examples 3 and 4

  The present inventor performed an electromagnetic field simulation in order to investigate the magnetic coupling state in the power transmitting and receiving apparatuses 200A and 200B. As a simulator, “Maxwell” manufactured by Ansys was used. The inner diameter of the housing 231 of the wearable device 230 was set to 20 mm, and the outer diameter was set to 28 mm. The cross-sectional diameter of the primary coil 253 and the secondary coil 233 was set to 0.22 mm, and the number of turns was set to 20T. The thickness of the magnetic plates 234 and 254 was set to 0.2 mm. The magnetic plates 234 and 254 have magnetic permeability (relative magnetic permeability) set to 120 and 300, respectively. The magnetic permeability of the magnetic body 257 was set to 300.

  FIG. 15 is a table showing analysis results including coupling coefficients. “Rdc” indicates DC resistance. In Comparative Examples 3 and 4, a high coupling coefficient was obtained. In particular, compared to Comparative Example 3, the inductance and coupling coefficient of Comparative Example 4 were higher. If the inductance per unit number of turns is high, the number of turns of the coil can be reduced, which contributes to downsizing of the device. This also makes it possible to reduce the DC resistance.

  6). Various other embodiments

  The present invention is not limited to the embodiment described above, and other various embodiments can be realized.

  In the above embodiments (including Comparative Examples 3 and 4), each component constituting the power transmission device and the wearable device may have a shape other than a circle, for example, an ellipse or a polygon.

  In each of the above embodiments (including Comparative Examples 3 and 4), the magnetic bodies 57 and 257 have a solid structure, but may have a hollow structure. Since magnetic flux collects on the outer peripheral side of the magnetic bodies 57 and 257 from the arrangement of the primary coil and the secondary coil, it is effective to arrange a magnetic material in that region. That is, even when the magnetic bodies 57 and 257 are thin hollow structures, good magnetic characteristics can be obtained.

  Alternatively, the magnetic bodies 57 and 257 may be formed by rounding or spiraling a rounded magnetic sheet. Even in this case, the magnetic bodies 57 and 257 may have a substantially solid structure or a hollow structure.

  In the first embodiment (see FIG. 4), the upper end of the first conductor 351 is provided at a position lower than the upper end of the inner peripheral surface 31a of the housing 31, but is provided up to the upper end of the inner peripheral surface 31a. It may be. Similarly, the second conductor 352 may be provided up to the upper end of the outer peripheral surface 31b.

  The conductor 35 may be provided on the inner wall surface inside the housing 31. In this case, the arrangement of the conductors 35 can be set as appropriate as shown in FIG.

  The arrangement and form of the circuit device 29 and the batteries 27 and 227 are not limited to the above embodiment. For example, as shown in FIG. 4, a part of the battery 27 may be cut out as viewed in one section, and a part of the circuit device 29 or other parts may be arranged in the cut-out space.

  It is also possible to combine at least two feature portions among the feature portions of each embodiment described above.

27, 227 ... battery 29 ... circuit equipment 30, 130, 230 ... wearable equipment 31, 23 ... casing 31a ... inner peripheral surface 31b ... outer peripheral surface 31c ... end surface (first end surface)
31d ... end face (second end face)
32, 232 ... Air core 33, 233 ... Secondary coil 34, 54, 234, 254 ... Magnetic plate 35, 85 ... Conductor 35a ... Conductor end 36, 236 ... Secondary antenna 50, 150, 250 ... Power transmission device 52, 252 ... Protruding portion 53, 253 ... Primary coil 56, 256, 259 ... Primary antenna portion 57, 257 ... Magnetic body 80 ... Wearable device 100A, 100B, 200A, 200B ... Power transmission / reception device 351 ... First Conductor 352 ... second conductor

Claims (9)

A wearable device capable of receiving electric power in a non-contact manner from a power transmission device having a protrusion and a primary antenna portion,
A housing that has an air core portion that penetrates, and is configured such that the protruding portion of the power transmission device can be inserted into the air core portion;
A secondary antenna unit that is coaxial with the air core of the housing and is housed in the housing;
A wearable device comprising: a conductor provided in the housing. The wearable device according to claim 1,
The primary antenna part of the power transmission device is
A first magnetic plate;
A magnetic body provided so as to protrude from the first magnetic plate in the protruding direction of the protruding portion;
When having a primary coil mounted on the first magnetic plate and provided around the magnetic body,
The secondary antenna unit is
A second magnetic plate having an air core portion facing the first magnetic plate in the axial direction in a state where the protrusion is inserted into the air core portion of the housing;
A wearable device having a secondary coil mounted on the second magnetic plate. The wearable device according to claim 1 or 2,
The housing has an inner peripheral surface;
The said conductor is a wearable apparatus provided in a part of said inner peripheral surface at least. The wearable device according to claim 3,
The housing further has an outer peripheral surface,
The said conductor is further provided in at least one part of an outer peripheral surface. Wearable apparatus. The wearable device according to claim 4,
The conductor is
A first conductor provided on at least a part of the inner peripheral surface;
A wearable device comprising: a second conductor provided on at least a part of the outer peripheral surface. The wearable device according to claim 4,
The housing is
A first end surface provided between the inner peripheral surface and the outer peripheral surface;
A second end surface provided between the inner peripheral surface and the outer peripheral surface, on the opposite side of the first end surface, and provided closer to the secondary antenna unit than the first end surface; ,
The said conductor is continuously provided from the said inner peripheral surface to the said outer peripheral surface through the said 1st end surface. Wearable apparatus. The wearable device according to any one of claims 3 to 6,
The conductor has a conductor end portion that is an end portion on a side close to the secondary antenna portion,
A wearable device further comprising a battery disposed in a position farther from the secondary antenna portion in the axial direction than the position of the conductor end portion in the housing. The wearable device according to any one of claims 1 to 7,
The conductive material is a non-magnetic material. A power transmission device having a protrusion and a primary antenna;
Comprising a wearable device capable of receiving power from the power transmission device in a contactless manner;
The wearable device is
A housing that has an air core portion that penetrates, and is configured such that the protruding portion of the power transmission device can be inserted into the air core portion;
A secondary antenna unit that is coaxial with the air core of the housing and is housed in the housing;
A non-contact power transmitting and receiving device having a conductor provided in the housing.

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