Coil unit

Abstract

To provide a coil unit configured to improve the strength of a housing case while maintaining power feeding performance.SOLUTION: A coil unit (10) includes: a ferrite plate (13); a coil substrate (14) with a coil (112) for transmitting or receiving AC power, mounted on the ferrite plate; a housing case (11) for housing the ferrite plate and the coil substrate laminated in a lamination direction; and a plurality of columnar support formation sections (21, 22, 23, 24) each having columnar supports (31, 32) inserted through openings (41, 42) that penetrate in the lamination direction through the ferrite plate and the coil substrate, and holding the space in the housing case in the lamination direction, each of the columnar support formation sections being formed along a direction of a magnetic flux flowing toward a central axis from an outer edge of the ferrite plate, the magnetic flux being generated by the coil when transmitting or receiving the AC power, and being separated from each other around the central axis when viewed in the lamination direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a coil unit. [Background technology]

[0002] In recent years, a contactless power supply system that supplies power to electric vehicles contactlessly using a technology called DWPT (Dynamic Wireless Power Transfer: Dynamic Wireless Charging) has been developed. In this contactless power supply system, power is transmitted contactlessly from a power transmission coil embedded on the ground side to a power receiving coil mounted under the floor of the vehicle. For example, Patent Document 1 discloses a coil unit used in the above-mentioned contactless power supply system.

[0003] This coil unit includes a housing case, and the coil, ferrite plate, substrate, etc. are arranged inside the housing case. Electrical elements such as a capacitor are mounted on the surface of the substrate. Furthermore, slits are formed in the substrate, so that even if an external impact is applied to the housing case and bending deformation occurs, the impact is absorbed at the slits, and damage such as cracking of the substrate itself is suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-26496 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the coil unit described in the above Patent Document 1, the stress applied to the substrate is only absorbed by slits, and therefore it is insufficient in terms of improving the strength of the housing itself. In addition, as a means for improving the strength of a housing such as a housing case, it is possible to simply provide supports in the internal space, but in a configuration in which supports are provided randomly, there is a risk that the flow of magnetic flux in the ferrite plate will be blocked, resulting in a decrease in power supply performance. The present disclosure has been created in view of the above points, and its purpose is to provide a coil unit that can improve the strength of the housing case while maintaining the power supply performance. [Means for solving the problem]

[0006] The present disclosure can be realized in the following forms.

[0007] According to one embodiment of the present disclosure, there is provided a coil unit for use in a contactless power supply system (300), comprising: a ferrite plate (13), a coil board (14) on which a coil (112) for transmitting or receiving AC power is mounted and placed on the ferrite plate, a housing case (11) for housing the ferrite plate and the coil board in a stacked state in a stacking direction, and a plurality of support forming parts (21, 22, 23, 24) having supports (31, 32) inserted into openings (41, 42) penetrating the ferrite plate and the coil board in the stacking direction, for maintaining a space in the stacking direction within the housing case, the support forming parts being provided along the flow direction of magnetic flux that flows from an outer edge of the ferrite plate toward a central axis generated by the coil when transmitting or receiving the AC current, and being provided at a distance from each other around the central axis as viewed in the stacking direction. According to the above configuration, the plurality of pillar forming parts are arranged along the flow direction of the magnetic flux flowing from the outer edge of the ferrite plate toward the central axis, and are spaced apart from each other around the central axis when viewed in the stacking direction. In the portion of the ferrite plate where the pillar forming parts are arranged, the flow of magnetic flux from the outer edge of the ferrite plate toward the central axis is obstructed, but in the region between the pillar forming parts arranged at a distance around the central axis, the flow of magnetic flux from the outer edge of the ferrite plate to the central axis can be ensured. Therefore, with this coil unit, the strength of the housing case can be improved while maintaining the power supply performance.

[0008] According to another embodiment of the present disclosure, there is provided a coil unit for use in a contactless power supply system, the coil unit including: a magnetic material plate; a coil for transmitting or receiving AC power, the coil being placed on the magnetic material plate; a housing case for housing the magnetic material plate and the coil in a stacked state in a stacking direction, the housing case having a first cover member and a second cover member separable in the stacking direction; and a plurality of support pillar forming parts having supports for connecting the first cover member and the second cover member, penetrating the magnetic material plate and the coil in the stacking direction from the first cover member to the second cover member, the support pillar forming parts being provided along the flow direction of magnetic flux generated by the coil when transmitting or receiving the AC power, the magnetic flux flowing from the outer edge of the magnetic material plate toward the central axis or from the central axis toward the outer edge, and being provided at a distance from each other around the central axis as viewed in the stacking direction. According to the above configuration, the plurality of support pillar forming parts are provided along the flow direction of the magnetic flux flowing from the outer edge of the magnetic material plate toward the central axis or from the central axis to the outer edge, and are spaced apart from each other around the central axis when viewed in the stacking direction. In the magnetic material plate, the flow of the magnetic flux from the outer edge of the magnetic material plate toward the central axis or from the central axis to the outer edge is obstructed in the portion where the support pillar forming parts are provided, but the flow of the magnetic flux from the outer edge of the magnetic material plate to the central axis can be ensured in the region between the support pillar forming parts provided at a distance around the central axis. Therefore, according to this coil unit, it is possible to improve the strength of the housing case while maintaining the power supply performance. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing a schematic configuration of a traveling power supply system in a first embodiment of the present disclosure. [Diagram 2] 1 is a diagram showing a circuit configuration of a traveling power supply system in a first embodiment of the present disclosure. [Diagram 3] 1 is an exploded perspective view showing an internal configuration of a coil unit in a first embodiment of the present disclosure. FIG. [Figure 4] FIG. 2 is a plan view illustrating a coil unit. [Diagram 5] 5 is a cross-sectional view showing a schematic cross-sectional view of the coil unit taken along line VV in FIG. 4. [Figure 6] FIG. 2 is a plan view showing a ferrite plate. [Figure 7] FIG. 2 is a plan view showing a coil substrate. [Figure 8] FIG. 11 is a plan view showing a ferrite plate in a second embodiment of the present disclosure. [Figure 9] FIG. 11 is a plan view showing a ferrite plate in a third embodiment of the present disclosure. [Figure 10] FIG. 13 is a plan view showing a ferrite plate in a fourth embodiment of the present disclosure. [Figure 11] FIG. 13 is an exploded perspective view showing the internal configuration of a coil unit in a fifth embodiment of the present disclosure. [Figure 12] 12 is a cross-sectional view showing a schematic cross-sectional view of the coil unit in the fifth embodiment, taken along line XII-XII in FIG. [Figure 13] FIG. 13 is a cross-sectional view illustrating a coil unit according to a sixth embodiment of the present disclosure. [Figure 14] FIG. 13 is a partial cross-sectional view illustrating a coil unit according to a seventh embodiment of the present disclosure. [Figure 15] FIG. 13 is a cross-sectional view illustrating a coil unit according to an eighth embodiment of the present disclosure. [Figure 16] FIG. 13 is a plan view illustrating a coil according to a ninth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments of the present disclosure will be described with reference to FIGS.

[0011] A. First embodiment: A1. Configuration of the non-contact power supply system 300: A coil unit 10 of the first embodiment will be described with reference to Figs. 1 to 7. The coil unit 10 of the first embodiment is used in a contactless power supply system 300. As shown in Fig. 1, the contactless power supply system 300 includes a power transmitter 100 installed on a road RS and a power receiver 205 mounted on a vehicle 200. The contactless power supply system 300 is a system capable of supplying power from the power transmitter 100 to the power receiver 205 of the vehicle 200 in a contactless manner. In this embodiment, the coil unit 10 is provided in the power transmitter 100.

[0012] The power transmitter 100 includes a power transmission resonant circuit 110, a power transmission circuit 120, and a power supply circuit 130. In this embodiment, the power transmission resonant circuit 110, the power transmission circuit 120, and the power supply circuit 130 are embedded inside the road RS. A plurality of power transmission resonant circuits 110 and power transmission circuits 120 may be provided, and may be provided, for example, in a continuous arrangement along the extension direction of the road RS, which is the traveling direction of the vehicle 200. The power transmission resonant circuit 110, the power transmission circuit 120, and the power supply circuit 130 do not necessarily need to be embedded inside the road RS, and may be provided, for example, at a position on the road RS that does not impede the traveling of the vehicle 200. The power transmission circuit 120 and the power supply circuit 130 are preferably provided near the power transmission resonant circuit 110.

[0013] The power supply circuit 130 supplies AC power from an AC power source such as a system power source to the power transmission circuit 120 via a power cable. The power transmission circuit 120 is an AC conversion circuit having a rectifier circuit, an inverter circuit, a filter circuit, etc. The power transmission circuit 120 converts the AC power supplied from the power supply circuit 130 into DC power, converts the DC power into high-frequency AC power that can be transmitted to the power receiver 205 of the vehicle 200, and supplies the DC power to the power transmission resonant circuit 110.

[0014] The power transmitting resonant circuit 110 transmits AC power induced in the power transmitting coil 112 (see FIG. 2) to the power receiving resonant circuit 210 by utilizing the electromagnetic induction phenomenon. As shown in FIG. 2, the power transmitting resonant circuit 110 is an LC circuit in which the power transmitting coil 112 and a first capacitor 116 functioning as a resonant capacitor are connected in series. The power transmitting coil 112 and the first capacitor 116 may be connected in parallel. The power transmitting coil 112 is included in the coil unit 10 of this embodiment.

[0015] The vehicle 200 is configured as a vehicle equipped with a drive motor, such as an electric vehicle or a hybrid vehicle. As shown in Fig. 1, the vehicle 200 includes a power receiver 205 and a battery 230. The power receiver 205 includes a power receiving resonant circuit 210 and a power receiving circuit 220.

[0016] 2, the power receiving resonant circuit 210 includes a power receiving coil 212 and a second capacitor 216 that functions as a resonant capacitor. The power receiving resonant circuit 210 is disposed, for example, on the bottom surface of the vehicle 200. The power receiving resonant circuit 210 receives, from the power receiving coil 212, AC power induced in the power transmitting resonant circuit 110 of the power transmitter 100.

[0017] The power receiving circuit 220 converts the AC power output from the power receiving resonant circuit 210 into DC power. The power receiving circuit 220 has, for example, a filter circuit, a rectifier circuit that converts the AC power into DC power, and a power conversion circuit that converts the AC power into DC power suitable for charging the battery 230. The battery 230 is, for example, a secondary battery that outputs DC power for driving a drive motor that is a drive source of the vehicle 200. The DC power output from the power receiving circuit 220 can be used to charge the battery 230. The DC power from the power receiving circuit 220 may be used to charge an auxiliary battery (not shown) or to drive the drive motor or auxiliary equipment.

[0018] A2. Coil unit 10 configuration: Next, the configuration of the coil unit 10 will be described with reference to Fig. 3. As shown in Fig. 3, the coil unit 10 includes a housing case 11, an aluminum plate 12, a ferrite plate 13, and a coil substrate 14. As described above, in Fig. 1, in order to facilitate understanding of the technology, the coil unit 10 is illustrated as including the power transmitting resonant circuit 110 and the power transmitting circuit 120 of the power transmitter 100, but they do not have to be included. The coil unit 10 may include, for example, any other members included in the power transmitting resonant circuit 110, the power transmitting circuit 120, and the power supply circuit 130.

[0019] Incidentally, the coil unit 10 further includes a plurality of support pillar forming parts 21, 22, 23, 24 (see FIG. 4) for maintaining the vertical space within the housing case 11. However, the detailed configuration of the plurality of support pillar forming parts will be described with reference to the figures following FIG. 4, and are not shown in FIG. 3.

[0020] The housing case 11 is configured to have an upper cover 15 and a lower cover 16. The upper cover 15 and the lower cover 16 are non-conductive and are formed of a non-magnetic material such as resin. In this embodiment, the boundary between the upper cover 15 and the lower cover 16 in the vertical direction coincides with the position of the upper surface 12T of the aluminum plate 12 (see FIG. 5). In this embodiment in which the lower cover 16 is positioned below the upper surface 12T of the aluminum plate 12, the lower cover 16 does not have to be made of a non-magnetic, non-conductive material as described above, and may be made of a material having shielding properties similar to the aluminum plate 12. By making the side surface of the housing case 11 out of a resin material, it is possible to reduce or prevent the magnetic flux generated from the power transmission coil 112 from being blocked.

[0021] The top cover 15 has a substantially flat plate shape. An upper surface 15T of the top cover 15 is a surface of the coil unit 10 that faces the power receiving coil 212 of the vehicle 200 (hereinafter, also referred to as a "coil facing surface"). A lower surface 15B of the top cover 15 covers an upper surface 14T of the coil board 14, and protects the coil board 14 and the power transmitting coil 112 from the outside air and the like. In this embodiment, the top cover 15 is embedded in the road RS, but may be exposed from the road RS.

[0022] Top cover 15 and bottom cover 16 are fitted together with a fastener (not shown) to form housing case 11 that houses coil substrate 14, ferrite plate 13, and aluminum plate 12. Inside housing case 11, aluminum plate 12, ferrite plate 13, and coil substrate 14 are provided, stacked in this order from bottom cover 16 toward top cover 15.

[0023] Aluminum plate 12 has a substantially rectangular external shape in a plan view. Aluminum plate 12 is provided with upper surface 12T thereof in contact with lower surface 13B of ferrite plate 13. Aluminum plate 12 is formed of aluminum or an aluminum alloy. Aluminum plate 12 dissipates heat generated in power transmission coil 112. Aluminum plate 12 also has a shielding function to prevent magnetic flux generated from coil substrate 14 from escaping to the outside. Note that instead of aluminum plate 12, a plate member for heat dissipation and shielding may be formed using a copper or other metal plate.

[0024] The ferrite plate 13 has a substantially rectangular external shape in a plan view. The ferrite plate 13 has an upper surface 13T for placing the coil substrate 14 thereon, and a lower surface 13B located on the back side of the upper surface 13T. The upper surface 13T is a surface that is located closer to the coil-facing surface than the lower surface 13B. The ferrite plate 13 is located such that the upper surface 13T faces the lower surface 14B of the coil substrate 14. In this embodiment, the ferrite plate 13 is provided in a state in which it abuts against the lower surface 14B of the coil substrate 14, but the ferrite plate 13 may be provided in a state spaced apart from the lower surface 14B of the coil substrate 14.

[0025] The coil substrate 14 is a rigid type printed wiring board. The coil substrate 14 has a substantially rectangular external shape in a plan view. The power transmission coil 112 is formed inside the coil substrate 14. In this embodiment, the power transmission coil 112 is a laminated coil formed by laminating a plurality of annular conductors surrounding the periphery of a central axis CX. The power transmission coil 112 is provided with a hollow region that does not include a conductor at a position including the central axis CX. The central axis CX is the central axis CX of the coil unit 10, and passes through the centers of the aluminum plate 12, the ferrite plate 13, and the coil substrate 14, and extends in the vertical direction. The direction in which the central axis CX extends corresponds to the "lamination direction" in which the ferrite plate 13 and the coil substrate 14 are laminated.

[0026] The power transmitting coil 112 may be made of a conductor such as a magnet wire, and in this case, the power transmitting coil 112 may be formed by resin molding a magnet wire wound in a coil shape. The power transmitting coil 112 may be, for example, a spiral coil in which a conductor is cut into a spiral shape, or may be one of various coils such as a helical coil in which a conductor having a circular or rectangular cross-sectional shape is wound in a spiral shape. When a conductor is used for the power transmitting coil 112, the conductor may be formed of a twisted wire.

[0027] When an AC current flows through the power transmitting coil 112, a magnetic flux is formed around the power transmitting coil 112. The magnetic flux formed around the power transmitting coil 112 passes through the hollow region of the power transmitting coil 112, the ferrite plate 13, and the outer periphery of the power transmitting coil 112. When a part of the magnetic flux formed around the power transmitting coil 112 interlinks with the power receiving coil 212, an AC current flows through the power receiving coil 212. When an AC current flows through the power receiving coil 212, a magnetic flux is also formed around the power receiving coil 212. The magnetic flux interlinking with both the power transmitting coil 112 and the power receiving coil 212 allows the power receiving coil 212 to receive power from the power transmitting coil 112 in a non-contact manner.

[0028] A3. Configuration of the support forming parts 21, 22, 23, 24: As shown in Fig. 4, a plurality of (four in this embodiment) support pillar forming parts 21, 22, 23, 24 are provided in the housing case 11. For ease of understanding, Fig. 4 omits the illustration of the top cover 15, and illustrates each member in the housing case 11 as viewed from the top cover 15 side. As shown in Fig. 4, the four support pillar forming parts 21, 22, 23, 24 are composed of a first support pillar forming part 21, a second support pillar forming part 22, a third support pillar forming part 23, and a fourth support pillar forming part 24. These support pillar forming parts 21, 22, 23, 24 are radially arranged at equal intervals of about 90 degrees around the central axis CX in the order of the first support pillar forming part 21, the second support pillar forming part 22, the third support pillar forming part 23, and the fourth support pillar forming part 24. The support pillar forming portions 21, 22, 23, 24 are provided in point symmetry with respect to the central axis CX when viewed in the stacking direction.

[0029] Although the support pillar forming parts 21, 22, 23, and 24 are installed at different positions within the coil unit 10, they have the same configuration, so the configuration of the first support pillar forming part 21 will be described as a representative example among the support pillar forming parts 21, 22, 23, and 24. The first support pillar forming part 21 has a first support pillar 31 and a second support pillar 32. The second support pillar 32 is provided at a position closer to the central axis CX than the first support pillar 31. The arrangement direction of the first support pillar 31 and the second support pillar 32 coincides with the flow direction of the magnetic flux from the outer edge of the ferrite plate 13 toward the central axis CX.

[0030] The first support pillar forming portion 21 is aligned along the magnetic flux flow direction as a whole, with the multiple supports 31, 32 being arranged along the magnetic flux flow direction. The supports 31, 32 are inserted into openings 41, 42 penetrating the ferrite plate 13 and the coil substrate 14 in the stacking direction. As shown in FIG. 5, the first support pillar 31 is inserted into a first opening 41 penetrating the ferrite plate 13 and the coil substrate 14 in the stacking direction. Similarly, the second support pillar 32 is inserted into a second opening 42 penetrating the ferrite plate 13 and the coil substrate 14 in the stacking direction.

[0031] As shown in FIG. 4, the pillars 31 and 32 are cylindrical and of the same size. The cross-sectional areas of the pillars 31 and 32 in a plane perpendicular to the central axis CX are sufficiently small compared to the area of ​​the upper surface 13T of the ferrite plate 13. The first pillar 31 and the second pillar 32 constituting the first pillar forming portion 21, and the first pillar 31 and the second pillar 32 constituting the third pillar forming portion 23 are arranged on one diagonal line passing through the central axis CX. The first pillar 31 and the second pillar 32 constituting the second pillar forming portion 22, and the first pillar 31 and the second pillar 32 constituting the fourth pillar forming portion 24 are arranged on another diagonal line passing through the central axis CX. When the four pillar forming portions are viewed as a whole, the pillars 31 and 32 are arranged radially and stepping-stone-like in a plan view in the stacking direction.

[0032] Note that the openings 41, 42 and the pillars 31, 32 are not provided on or near the central axis CX. Each of the pillars 31, 32 is disposed between the turns of the power transmission coil 112, for example, between the first and second turns of the coil as viewed in the stacking direction, so as not to interrupt the flow of current in the coil substrate 14. Note that in Figs. 4 and 7, the power transmission coil 112 wound in a spiral shape is illustrated as an example, and the pillars 31, 32 are provided between the turns, but the positions of the pillars 31, 32 are not limited to between the turns and may be any position that does not interrupt the flow of current in the power transmission coil 112.

[0033] 5, each of the pillars 31, 32 extends in the stacking direction from the lower surface 15B of the top cover 15 to the upper surface 12T of the aluminum plate 12, and is formed integrally with the top cover 15. The pillars 31, 32 are provided continuously from the aluminum plate 12 to the top cover 15, thereby maintaining the space in the housing case 11 in the vertical direction. The pillars 31, 32 are non-conductive and are formed of a non-magnetic material such as resin. Therefore, they are manufactured, for example, by integral molding, when the top cover 15, which is also formed of resin as described above, is molded.

[0034] 5 to 7, the ferrite plate 13 and the coil substrate 14 are formed with a plurality of openings 41, 42 through which the pillars 31, 32 are inserted. The openings 41, 42 of the ferrite plate 13 and the coil substrate 14 are provided in the same arrangement as the plurality of pillars 31, 32 so as to correspond in the stacking direction to the positions where the plurality of pillars 31, 32 of each of the pillar forming portions 21, 22, 23, 24 described above in detail are provided.

[0035] As shown in Fig. 6, the ferrite plate 13 is provided with a total of eight openings 41A, 42A in a radial and stepping-stone pattern, including four first openings 41A through which the first struts 31 are inserted and four second openings 42A through which the second struts 32 are inserted. Similarly, as shown in Fig. 7, the coil substrate 14 is provided with a total of eight openings 41B, 42B in a radial and stepping-stone pattern, including four first openings 41B through which the first struts 31 are inserted and four second openings 42B through which the second struts 32 are inserted. In the following description, the openings 41A, 42A formed in the ferrite plate 13 and the openings 41B, 42B formed in the coil substrate 14 are simply referred to as "openings 41, 42" when there is no particular need to distinguish between them.

[0036] Each opening 41, 42 is formed as a through hole having a circular cross section large enough to allow the support 31, 32 to be inserted therethrough. The openings 41A, 42A of the ferrite plate 13 and the openings 41B, 42B of the coil substrate 14 are all the same size. In other words, the cross section of each support 31, 32 in a direction perpendicular to the lamination direction is the same as the cross section of each opening 41, 42 in a direction perpendicular to the lamination direction. Strictly speaking, each support 31, 32 is capable of being inserted into each opening 41, 42, so the cross section of each support 31, 32 is smaller than the cross section of each opening 41, 42. However, the above "same" is not limited to "same" in the strict sense, but is interpreted as "same" if it has an identity within a range that is usually determined to be "same" to the extent that the support 31, 32 can be inserted into the opening 41, 42 in light of the technical common sense of the technical field.

[0037] In Fig. 6, the magnetic flux flowing through the ferrite plate 13 is illustrated by multiple arrows. During power transmission, the magnetic flux generated from the power transmission coil 112 toward the power receiving coil 212 facing the power transmission coil 112 flows from the outer edge of the ferrite plate 13 toward the central axis CX, as shown in Fig. 6. Since the openings 41A, 42A are provided radially and in a stepping-stone pattern, the magnetic flux flows toward the central axis CX in most parts where the openings 41A, 42A are not provided.

[0038] A4.Effects: (1) In the coil unit 10 of the first embodiment, the plurality of pillar forming parts 21, 22, 23, 24 are provided along the flow direction of the magnetic flux flowing from the outer edge of the ferrite plate 13 toward the central axis CX, and are spaced apart from each other around the central axis CX when viewed in the stacking direction. In the portion of the ferrite plate 13 where the pillar forming parts 21, 22, 23, 24 are provided, the flow of the magnetic flux from the outer edge of the ferrite plate 13 toward the central axis CX is obstructed. However, in the region between the pillar forming parts provided at a distance around the central axis CX, the flow of the magnetic flux from the outer edge of the ferrite plate 13 to the central axis CX can be ensured. Specifically, the openings 41, 42 and the pillars 31, 32 are provided radially and stepping-stone-like, and the pillar forming parts 21, 22, 23, 24 are not provided so as to block all of the flow of the magnetic flux.

[0039] For example, in a configuration in which the pillars and openings are continuously arranged in a ring shape including the central axis CX in the inner region as viewed in the stacking direction, most of the flow of magnetic flux from the outer edge toward the central axis CX is blocked. However, according to the first embodiment, the pillar forming parts 21, 22, 23, and 24 are arranged along the direction of the magnetic flux flow and spaced apart from each other around the central axis CX. Therefore, the flow of magnetic flux is not obstructed in the areas where the pillars 31 and 32 and the openings 41 and 42 are not present.

[0040] The strength of the casing 11 can be improved by the plurality of support columns 31, 32. That is, according to the coil unit 10 of the first embodiment, the strength of the casing 11 can be improved while maintaining the power supply performance by keeping the flow of magnetic flux good.

[0041] (2) In the coil unit 10 of the first embodiment, the support pillar forming portions 21, 22, 23, 24 are provided in point symmetry with respect to the central axis CX when viewed in the stacking direction. This allows the magnetic flux density in the ferrite plate 13 to be uniform, enabling well-balanced power transmission.

[0042] (3) In the coil unit 10 of the first embodiment, the cross-sectional shape of each of the pillars 31, 32 in a direction perpendicular to the stacking direction is substantially the same as the cross-sectional shape of each of the openings 41, 42 in a direction perpendicular to the stacking direction. Therefore, compared to a configuration in which the cross-sectional shape of each of the openings 41, 42 is larger than the cross-sectional shape of each of the pillars 31, 32, for example, it is easier to ensure an area in the ferrite plate 13 through which magnetic flux flows.

[0043] (4) In the coil unit 10 of the first embodiment, the pillars 31, 32 are integrally molded with the top cover 15. This makes it easy to manufacture the pillars 31, 32, and also increases the strength compared to a configuration in which the pillars and the housing case 11 are manufactured as separate members and then bonded together.

[0044] (5) In the coil unit 10 of the first embodiment, the openings 41, 42 and the pillars 31, 32 are not provided on or near the central axis CX. In the vicinity of the central axis CX, magnetic flux flowing from the outer edge of the ferrite plate 13 to the central axis CX is concentrated and the magnetic flux density is likely to be high. Therefore, by not providing the openings 41, 42 in the vicinity of the central axis CX, magnetic saturation in the vicinity of the central axis CX can be suppressed.

[0045] B. Second embodiment: Next, a second embodiment will be described with reference to Fig. 8. In the second embodiment and each embodiment described later, the overall configuration of the contactless power supply system 300 (Fig. 1), the circuit configuration of the contactless power supply system 300 (Fig. 2), and the overall configuration of the coil unit 10 (Fig. 3) excluding the support pillar forming parts 21, 22, 23, and 24 are substantially similar to those in the first embodiment, so that the same reference numerals are used for substantially the same parts and description thereof will be omitted.

[0046] In the second embodiment, the four support pillar forming parts 21, 22, 23, 24 are arranged in point symmetry with the central axis CX as the center of symmetry, which is the same as the first embodiment, but the detailed configuration of each support pillar forming part 21, 22, 23, 24 is different. As shown in FIG. 8, a total of 16 openings are provided in the ferrite plate 13, penetrating radially and stepping-stone-like with the central axis CX as the center of symmetry. More specifically, four openings, a first opening 51A, a second opening 52A, a third opening 53A, and a fourth opening 54A, are formed as openings through which four support pillars (not shown) constituting the first support pillar forming part 21 are inserted. The first opening 51A, the second opening 52A, the third opening 53A, and the fourth opening 54A are provided at equal intervals in this order from the outer edge toward the central axis CX.

[0047] The opening area of ​​each of the openings 51A, 52A, 53A, 54A in a plane perpendicular to the stacking direction is smaller toward the central axis CX side than the openings on the outer edge side, and in this embodiment, it gradually becomes smaller. That is, the opening area of ​​the first opening 51A is the largest, and the opening areas of the second opening 52A, the third opening 53A, and the fourth opening 54A are smaller in this order. In other words, the opening area of ​​the opening formed on the central axis CX side in a plane perpendicular to the stacking direction is smaller than the opening area of ​​the opening formed on the outer edge side in a plane perpendicular to the stacking direction. Note that the other openings through which the pillars constituting the second pillar forming part 22, the third pillar forming part 23, and the fourth pillar forming part 24 are inserted have the same opening area. The pillars inserted into the openings 51A, 52A, 53A, 54A have shapes corresponding to the opening areas of the respective openings 51A, 52A, 53A, 54A.

[0048] According to the second embodiment, it is possible to obtain the same effects as those of the first embodiment. Furthermore, since the opening area is smaller in the opening closer to the central axis CX of the ferrite plate 13, it is possible to suppress magnetic saturation in the central portion of the ferrite plate 13 including the central axis CX where the magnetic density is likely to be high.

[0049] C. Third embodiment: Next, a third embodiment will be described with reference to Fig. 9. As shown in Fig. 9, the third embodiment is the same as the second embodiment in that the pillar forming parts 21, 22, 23, 24 each having four pillars are arranged point symmetrically with the central axis CX as the center of symmetry, but the detailed configuration of each pillar forming part 21, 22, 23, 24 is different. A total of 16 openings 61A, 62A, 63A, 64A are provided in the ferrite plate 13 so as to penetrate radially and stepping-stone like with the central axis CX as the center of symmetry.

[0050] More specifically, four openings, a first opening 61A, a second opening 62A, a third opening 63A, and a fourth opening 64A, are formed as openings through which four pillars (not shown) that constitute the first pillar forming portion 21 are inserted. The first opening 61A, the second opening 62A, the third opening 63A, and the fourth opening 64A are provided in this order from the outer edge toward the central axis CX.

[0051] The opening areas of the openings 61A, 62A, 63A, and 64A in a plane perpendicular to the stacking direction are the same. In this embodiment, the formation interval of the openings formed on the central axis CX side of the ferrite plate 13 is wider than the formation interval of the openings formed on the outer edge side. That is, the interval T1 between the first opening 61A and the second opening 62A, the interval T2 between the second opening 62A and the third opening 63A, and the interval T3 between the third opening 63A and the fourth opening 64A are wider in this order. The other openings through which the pillars constituting the second pillar forming portion 22, the third pillar forming portion 23, and the fourth pillar forming portion 24 are inserted are also spaced similarly. The pillars inserted into the openings 61A, 62A, 63A, and 64A have shapes corresponding to the respective openings 61A, 62A, 63A, and 64A.

[0052] According to the third embodiment, it is possible to obtain the same effects as those of the first embodiment. Furthermore, since the intervals of the openings formed on the central axis CX side of the ferrite plate 13 are wider than the intervals of the openings formed on the outer edge side, it is possible to suppress magnetic saturation in the central part of the ferrite plate 13 including the central axis CX where the magnetic density is likely to be high.

[0053] D. Fourth embodiment: Next, the fourth embodiment will be described with reference to FIG. 10. As shown in FIG. 10, the fourth embodiment is different from the first embodiment in that the four support formation parts 21, 22, 23, 24 are configured to have a single opening 71A, 72A, 73A, 74A and a support. The openings 71A, 72A, 73A, 74A and the support are rectangular in shape when viewed from the stacking direction, with the longitudinal direction extending from the outer edge toward the central axis CX. The ferrite plate 13 is provided with a total of four slit-shaped openings 71A, 72A, 73A, 74A radially arranged with the central axis CX as the center of symmetry. The support inserted into the openings 71A, 72A, 73A, 74A has a shape corresponding to each opening, that is, a rectangular column shape.

[0054] According to the fourth embodiment, it is possible to obtain the same effects as those of the first embodiment. Furthermore, since the support pillars can be easily formed continuously over a wide range from the outer edge of the ferrite plate 13 to the central axis CX, it is possible to improve the strength of the support pillars, and therefore the strength of the housing case 11.

[0055] E. Fifth embodiment: A coil unit 80 of a fifth embodiment shown in Fig. 11 and Fig. 12 is used on the power receiving side, i.e., in a vehicle 200, unlike the coil units 10 of the first to fourth embodiments. The coil unit 80 is configured as a part of a power receiver 205, and includes at least a power receiving coil 212 of a power receiving circuit 220 and a power receiving resonant circuit 210. The coil unit 80 may be configured as the entire power receiver 205. Fig. 12 shows a cross section of the coil unit 80 taken along line XII-XII shown in Fig. 11.

[0056] The coil unit 80 includes a housing case 81, an aluminum plate 82, a magnetic material plate 83, a coil 84, four support pillar forming portions P1, and a plurality of screws 98.

[0057] The storage case 81 is configured to have an upper cover 85 and a lower cover 86. The upper cover 85 and the lower cover 86 are formed of a non-conductive and non-magnetic material such as resin. As shown in FIG. 12, in the fifth embodiment, the boundary between the upper cover 85 and the lower cover 86 in the vertical direction coincides with the position of the lower surface of the coil 84. The lower cover 86 has a substantially flat plate shape. The upper cover 85 has a structure in which a wall protruding downward is formed around the entire periphery of a substantially flat plate-shaped member. Then, with the lower end face of the wall being disposed in contact with the upper surface of the lower cover 86, the upper cover 85 and the lower cover 86 are fitted together by a fixing device (not shown) to form the storage case 81. The storage case 81 accommodates the aluminum plate 82, the magnetic material plate 83, and the coil 84, which are stacked on top of each other. In the fifth embodiment, the upper cover 85 is disposed in contact with the bottom 290 of the main body of the vehicle 200. Therefore, in the fifth embodiment, the coil unit 80 is entirely exposed to the outside of the vehicle 200. The lower surface of the lower cover 86 faces the road. Therefore, the lower surface of the lower cover 86 faces the power transmitting coil 112 of the power transmitter 100. The upper cover 85 has a total of eight screw holes h1 formed therein. Similarly, the lower cover 86 has a total of eight screw holes h2 formed therein. Screws 98 are inserted into each of the screw holes h1 and h2. The screws 98 are screwed into the support member 91 described below. The lower cover 86 corresponds to a first cover member of the present disclosure. The upper cover 85 corresponds to a second cover member of the present disclosure.

[0058] The aluminum plate 82 has a similar configuration to the aluminum plate 12 of the first embodiment. The aluminum plate 82 has eight through holes h82 formed therein, penetrating in the thickness direction (vertical direction).

[0059] The magnetic material plate 83 has a similar configuration to the ferrite plate 13 of the first embodiment. Eight through holes h83 penetrating in the thickness direction (vertical direction) are formed in the magnetic material plate 83. In this embodiment, the magnetic material plate 83 is made of ferrite, but is not limited to ferrite and may be made of any material having magnetism.

[0060] The coil 84 has a similar configuration to the coil substrate 14 of the first embodiment. The coil 84 is formed with eight through holes h84 penetrating in the thickness direction (vertical direction).

[0061] The through hole h82 of the aluminum plate 82, the through hole h83 of the magnetic material plate 83, and the through hole h84 of the coil 84 are disposed at positions corresponding to each other in the up-down direction. The through holes h82 to 84 have the same dimensions. Therefore, as shown in FIG. 12, when the coil unit 80 is assembled, a total of eight through holes ht are formed that penetrate from the aluminum plate 82 to the coil 84.

[0062] Each of the four support pillar forming parts P1 shown in FIG. 11 has two support pillars 90. In the fifth embodiment, each support pillar 90 is composed of a single support pillar member 91. In the fifth embodiment, the support pillar member 91 is formed of a non-conductive and non-magnetic resin. As shown in FIG. 12, each support pillar 90 (each support pillar member 91) is housed in the above-mentioned through hole ht. Therefore, each support pillar forming part P1 penetrates the aluminum plate 82, the magnetic material plate 83, and the coil 84 in the stacking direction to reach from the lower cover 86 to the upper cover 85, and connects the lower cover 86 and the upper cover 85. Similarly to the support pillar forming parts 21 to 24 in the first embodiment, the support pillar forming parts P1 are radially arranged around the central axis CX at equal intervals of about 90 degrees. Each support pillar forming part P1 is provided point-symmetrically with respect to the central axis CX as the center of symmetry when viewed in the stacking direction. The support pillar member 91 has a cylindrical external shape in which an axial hole 92 is formed. The axial hole 92 is formed with a screw thread.

[0063] As shown in FIG. 12, the screw hole h1 formed in the top cover 85 has a stepped cross-sectional structure. A screw 98 is inserted into the screw hole h1. The tip of the screw 98 inserted into the screw hole h1 reaches the shaft hole 92 of the support member 91 and is screwed into the thread of the shaft hole 92. Therefore, the upper end of the support member 91 is joined to the top cover 85. Similarly, the screw hole h2 formed in the bottom cover 86 has a stepped cross-sectional structure. A screw 98 is inserted into the screw hole h2. The tip of the screw 98 inserted into the screw hole h2 reaches the shaft hole 92 of the support member 91 and is screwed into the thread of the shaft hole 92. Therefore, the lower end of the support member 91 is joined to the bottom cover 86. In this way, by screwing the upper and lower ends of the support member 91 into the screws 98, the support member 91 is fixed inside the coil unit 80, and a force can be applied between the upper cover 85 and the lower cover 86 to clamp and fasten the aluminum plate 82, the magnetic material plate 83, and the coil 84 in the vertical direction.

[0064] The procedure for assembling the coil unit 80 and attaching it to the vehicle 200 is as follows. First, the support 90 is fastened to the lower cover 86 with the screw 98. Next, the coil 84, the magnetic material plate 83, and the aluminum plate 82 are arranged and stacked in this order so that the support 90 is inserted into the through-hole of each plate. Next, the upper cover 85 and the support 90 are fastened to each other with the screw 98. The coil unit 80 thus completed is attached to the bottom 290 of the vehicle 200. This attachment may be realized, for example, by screwing the coil unit 80 to a protrusion provided in advance on the bottom 290. As described above, by first attaching the support 90 to the lower cover 86, the support 90 can be used as a positioning portion when arranging the plates 82, 83, and 84.

[0065] The coil unit 80 of the fifth embodiment described above has the same effect as the coil unit 10 of the first embodiment. That is, in the coil unit 80 of the fifth embodiment, a plurality of support pillar forming parts P1 are provided along the flow direction of the magnetic flux flowing from the outer edge of the magnetic material plate 83 toward the central axis CX, and are spaced apart from each other around the central axis CX when viewed in the stacking direction. In the magnetic material plate 83, in the portion where the support pillar forming parts P1 are provided, the flow of the magnetic flux from the outer edge of the magnetic material plate 83 toward the central axis CX or from the central axis CX to the outer edge of the magnetic material plate 83 is obstructed. However, in the region between the support pillar forming parts provided at a distance around the central axis CX, the flow of the magnetic flux from the outer edge of the magnetic material plate 83 to the central axis CX or the reverse flow can be ensured.

[0066] Moreover, the strength of the accommodating case 81 can be improved by the plurality of supports 90 (support members 91). That is, according to the coil unit 80 of the fifth embodiment, the strength of the accommodating case 81 can be improved while maintaining the power supply performance by maintaining the flow of magnetic flux well. Moreover, in the coil unit 80, the support forming portion P1 is provided in point symmetry with respect to the central axis CX as the center of symmetry when viewed in the stacking direction. Therefore, it is possible to transmit power efficiently while suppressing the obstruction of the flow of magnetic flux in the magnetic material plate 83. Moreover, the cross-sectional shape of each support 90 in a direction perpendicular to the stacking direction and the cross-sectional shape of the through hole ht in a direction perpendicular to the stacking direction are substantially the same. Therefore, for example, compared to a configuration in which the cross-sectional shape of each through hole ht is larger than the cross-sectional shape of each support 90, it is easier to ensure an area in the magnetic material plate 83 through which magnetic flux flows.

[0067] Since coil unit 80 is provided on bottom 290 of vehicle 200, a load is applied vertically downward due to its own weight. However, by joining both ends of support 90 penetrating aluminum plate 82, magnetic material plate 83, and coil 84 to upper cover 85 and lower cover 86, downward bending and falling of each member can be suppressed even in a state where the above-mentioned load is applied, and strength (resistance) against the load can be improved.

[0068] F. Sixth embodiment: The coil unit 80a of the sixth embodiment shown in FIG. 13 is different from the coil unit 80 of the fifth embodiment in that it includes a bottom cover 86a instead of the bottom cover 86, a spacer member 93 instead of the support member 91, and a screw 99 instead of the screw 98 inserted into the bottom cover 86a. The other configurations of the coil unit 80a of the sixth embodiment are the same as those of the coil unit 80, so the same components are given the same reference numerals and detailed description thereof is omitted. In the coil unit 80 of the fifth embodiment, the support 90 is formed of a single support member 91. In contrast, in the coil unit 80a of the sixth embodiment, the support 90 is formed of a spacer member 93 and a protrusion 861, which will be described later, of the bottom cover 86a.

[0069] The lower cover 86a has a protruding portion 861 at a position corresponding to the through hole ht. The protruding portion 861 contacts the coil 84 and the magnetic material plate 83, protrudes in the stacking direction, and penetrates the magnetic material plate 83 and the coil 84 in the stacking direction. The protruding portion 861 is integrally formed with the other parts of the lower cover 86a. Therefore, the protruding portion 861 is formed of a non-conductive resin like the lower cover 86a. The position of the upper end of the protruding portion 861 in the stacking direction coincides with the position of the upper surface of the magnetic material plate 83 in the stacking direction. The lower cover 86a has a screw hole h3 instead of the screw hole h1. The screw hole h3 opens on the lower surface of the lower cover 86a, extends in the stacking direction, and is located inside the protruding portion 861. The screw hole h3 is a stepped hole like the screw hole h1. A screw 99 is inserted into the screw hole h3. The screw 99 is slightly smaller than the screw 98. Note that a configuration may be adopted in which a screw 99 is used instead of the screw 98. In such a configuration, the screw hole h3 may be made larger.

[0070] A spacer member 93 is disposed in a portion of the through hole ht that corresponds to the aluminum plate 82, that is, the through hole h82. The spacer member 93 has a cylindrical external shape having an axial hole with a screw thread formed therein. The spacer member 93 is formed of a metal having a higher strength than the aluminum plate 82. Specifically, in the sixth embodiment, the spacer member 93 is formed of an aluminum alloy. The spacer member 93 may be formed of any metal, such as stainless steel, instead of an aluminum alloy. The tip of a screw 98 is inserted into the axial hole of the spacer member 93 from above, and the tip of a screw 99 is inserted into the axial hole of the spacer member 93 from below. Then, each screw 98, 99 is screwed into the axial hole of the spacer member 93. The thickness of the spacer member 93, that is, the dimension in the vertical direction (stacking direction) is the same as the thickness of the aluminum plate 82. The spacer member 93 is disposed in contact with the upper end surface of the protruding portion 861. Therefore, the position of the lower end surface of the spacer member 93 in the stacking direction coincides with the position of the upper end surface of the aluminum plate 82 in the stacking direction. In the sixth embodiment, the support 90 is composed of a protrusion 861 and a spacer member 93 arranged in contact with each other in the stacking direction. In the through hole ht, the position of the aluminum plate 82 can be prevented from blocking the magnetic flux even if a metal spacer member 93 is used. In addition, by using the metal spacer member 93, the strength of the support 90 can be increased, and the resistance to load can be further improved.

[0071] The coil unit 80a of the sixth embodiment described above has the same effects as the coil unit 80 of the fifth embodiment. In addition, since a part of the support 90 is made of the metal spacer member 93, the strength of the support 90 can be increased and the resistance to load can be further improved. Furthermore, by using the spacer member 93 at a position of the through hole ht corresponding to the aluminum plate 82, blocking of the magnetic flux can be suppressed compared to a configuration in which the spacer member 93 is used at a position corresponding to the magnetic material plate 83 or the coil 84.

[0072] G. Seventh embodiment: 14 differs from coil unit 80a of the sixth embodiment in that coil unit 80b of the seventh embodiment includes a bottom cover 86b instead of bottom cover 86a. Other configurations of coil unit 80b of the seventh embodiment are the same as those of coil unit 80a, so the same components are denoted by the same reference numerals and detailed descriptions thereof are omitted.

[0073] The lower cover 86b is different from the lower cover 86a of the sixth embodiment in that it is made of a resin containing reinforcing fibers. In the seventh embodiment, the "reinforcing fibers" refer to carbon fibers CF. Note that the reinforcing fibers are not limited to carbon fibers CF, and any type of fiber such as glass fibers may be used.

[0074] Here, the arrangement direction of the carbon fiber CF is different between the side wall portion 862 and the protruding end portion 863 constituting the protruding portion 861. The side wall portion 862 means a cylindrical portion in the protruding portion 861. The protruding end portion 863 is arranged at approximately the same position as the magnetic material plate 83 in the stacking direction (Z-axis direction). The protruding end portion 863 is arranged so as to contact the upper end of the cylindrical side wall portion 862 and close the large hole portion of the screw hole h3. The above-mentioned "arrangement direction of the carbon fiber CF" means the length direction of the carbon fiber CF. In the side wall portion 862, the arrangement direction of the carbon fiber CF is approximately parallel to the up-down direction (Z-axis direction). In contrast, in the protruding end portion 863, the carbon fiber CF is approximately parallel to the direction from the outer edge of the magnetic material plate 83 toward the center of the magnetic material plate 83 and the opposite direction. The arrangement direction of the carbon fiber CF can be adjusted, for example, by adjusting the position of the resin inlet in the mold when injection molding the lower cover 86b and the direction in which the resin flows. The reason why the arrangement direction of the carbon fibers CF in the lower cover 86b is set as described above will be described below.

[0075] When a current flows through the conductor C1 constituting the coil 84, a magnetic flux B1 is generated around the conductor C1. In FIG. 14, the direction of the magnetic flux B1 is indicated by a dashed arrow. The direction of the magnetic flux B1 in the vicinity of the side wall portion 862 is substantially vertical. Therefore, by making the length direction of the carbon fiber CF in the side wall portion 862 substantially vertical, the generation of eddy currents can be suppressed and eddy current loss can be suppressed. In addition, in the magnetic material plate 83, magnetic flux in the direction from the outer edge to the center and magnetic flux in the opposite direction are generated. In FIG. 14, the direction of the magnetic flux B2 in the direction from the outer edge to the center is diagrammatically indicated by a dashed arrow. By making the arrangement direction of the carbon fiber CF included in the protruding end portion 863 arranged at the position corresponding to the magnetic material plate 83 substantially parallel to the direction of the magnetic flux B2, the generation of eddy currents can be suppressed and eddy current loss can be suppressed.

[0076] The coil unit 80b of the seventh embodiment described above has the same effects as the coil unit 80a of the sixth embodiment. In addition, the lower cover 86b is made of a resin containing carbon fibers CF, and the carbon fibers CF are arranged in the protruding portion 861 so as to be aligned along the directions of the magnetic fluxes B1 and B2 in the protruding portion 861 generated by the conductor wire C1, thereby suppressing the generation of eddy currents and suppressing eddy current loss.

[0077] H. Eighth embodiment: 15 differs from coil unit 80a of the sixth embodiment in that it includes a bottom cover 86c instead of bottom cover 86a, a magnetic material plate 83c instead of magnetic material plate 83, and a coil 84c instead of coil 84. Since the other configurations of coil unit 80c of the eighth embodiment are the same as those of coil unit 80a, the same components are denoted by the same reference numerals and detailed descriptions thereof will be omitted.

[0078] The lower cover 86c is different from the protrusion 861 of the sixth embodiment only in that it includes a protrusion 861c instead of the protrusion 861. The side wall of the protrusion 861 of the sixth embodiment had a substantially cylindrical external shape. In contrast, the protrusion 861c of the eighth embodiment has a so-called tapered external shape in which the cross-sectional area perpendicular to the stacking direction becomes smaller as it moves upward along the stacking direction, in other words, as it moves from the coil 84c to the magnetic material plate 83c along the stacking direction. The size of the screw hole h3 is the same as that of the screw hole h3 of the protrusion 861 of the sixth embodiment. Therefore, the thickness of the side wall 862c of the eighth embodiment (thickness in the direction perpendicular to the stacking direction: thickness in the X-axis direction) gradually becomes smaller as it moves upward.

[0079] The magnetic material plate 83c differs from the magnetic material plate 83 only in that, instead of the through hole h83, a through hole whose opening area gradually decreases toward the top is formed. Similarly, the coil 84c differs from the coil 84 only in that, instead of the through hole h84, a through hole whose opening area gradually decreases toward the top is formed.

[0080] The external shape of the protruding portion 861c is a tapered shape in which the cross-sectional area in the direction perpendicular to the stacking direction decreases as it goes upward along the stacking direction, so that when assembling the coil unit 80c, the through holes of the coil 84c and the magnetic material plate 83c can be easily inserted into the protruding portion 861c. This makes it easier to position the magnetic material plate 83c and the coil 84c, and improves the work efficiency during manufacturing. In addition, the positions of the magnetic material plate 83c and the coil 84c along the stacking direction can be easily adjusted. Specifically, for example, when a gap of a predetermined dimension is to be provided between the lower surface of the coil 84c and the upper surface of the lower cover 86c, the size of the gap can be easily adjusted by adjusting the size of the through hole of the coil 84c and the taper angle of the protruding portion 861c to adjust the position of the coil 84c in the stacking direction.

[0081] I. Ninth embodiment: Coil unit 80 of the ninth embodiment differs from coil unit 80 of the fifth embodiment in that it includes coil 84d shown in Fig. 16 instead of coil 84, that it has a greater number of pillars 90, and that some of the multiple pillars 90 are configured with pillar members 91a instead of pillar members 91. The other components of coil unit 80 of the ninth embodiment are the same as those of coil unit 80 of the fifth embodiment, and therefore the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

[0082] In the ninth embodiment, the conductor wire C2 constituting the coil 84d is wound in a spiral shape for approximately three turns. A support 90 is disposed between each turn, on the outside of the conductor wire of the outermost turn, and on the inside of the conductor wire of the innermost turn. Among the support members constituting the support 90, the same support member 91 as the support member 91 of the fifth embodiment is given the same reference numeral. Therefore, this support member 91 is made of a non-conductive resin. In FIG. 16, this support member 91 is represented by a white circle. On the other hand, the support member 91a represented by a black circle in FIG. 16 has the same shape as the support member 91, but is made of a conductive material different from the support member 91. Specifically, in the ninth embodiment, the support member 91a is made of an aluminum alloy. The support member 91a may be made of a conductive material such as any type of metal, such as stainless steel, instead of an aluminum alloy.

[0083] The lower part of FIG. 16 shows the intensity of the magnetic flux in the Z-axis direction in the coil 84d along the X-axis direction. When the conductor C2 is energized, magnetic flux is generated around the conductor C2 of each turn. As shown in FIG. 16, the magnetic flux intensity peaks slightly outside the conductor C2 of the outermost turn and slightly inside the conductor C2 of the innermost turn. Between the outermost turn and the innermost turn, and between the innermost turns facing each other in the X-axis direction, the magnetic flux intensity is within an intensity region BAr, which is a region of relatively low intensity. This is because the magnetic fluxes of the conductors C2 arranged side by side cancel each other between the outermost turn and the innermost turn. Also, there is no conductor C2 between the innermost turns. The lower threshold −Bth and the upper threshold +Bth of the intensity region BAr are predetermined values ​​lower than the magnetic flux peaks in the vicinity of the conductors C2 constituting the outermost turn and the innermost turn.

[0084] In the sixth embodiment, the support 90 arranged at a position where the magnetic flux intensity is within the strength region BAr is composed of a metallic support member 91a. On the other hand, the support 90 arranged at a position where the magnetic flux is outside the strength region BAr is composed of a resin support member 91. This is because, by using the metallic support member 91a within the strength region BAr, the resistance to the load due to the weight of the coil unit 80 can be improved, and also, because the magnetic flux intensity is relatively low within the strength region BAr, the eddy current loss can be kept relatively small. On the other hand, by using the resin support member 91 at a position outside the strength region BAr, the occurrence of excessive eddy current loss can be suppressed.

[0085] The coil unit 80 of the ninth embodiment described above has the same effects as the coil unit 80 of the fifth embodiment. In addition, since the metal support members 91a are used within the strength region BAr, it is possible to improve the resistance to the load due to the coil unit 80's own weight while keeping eddy current loss relatively small. Furthermore, by using the resin support members 91 at positions outside the strength region BAr, it is possible to prevent excessive eddy current loss from occurring.

[0086] J. Other Embodiments: (J1) In each of the above embodiments, the pillar forming portions 21, 22, 23, 24, and P1 are configured to be provided in four pieces in point symmetry with the central axis CX as the center of symmetry when viewed in the stacking direction, but they do not have to be point symmetrical, and the number of pillar forming portions may be two, three, five or more. Also, the spacing angles between the pillar forming portions 21, 22, 23, 24, and P1 around the central axis CX do not have to be uniform.

[0087] (J2) In each of the above embodiments, the number of openings and pillars in one pillar forming portion 21, 22, 23, 24, P1 can be changed as appropriate.

[0088] (J3) The second and third embodiments may be combined to form ferrite plate 13 such that the intervals between the openings are wider and the opening areas are smaller on the central axis CX side than on the outer edge side.

[0089] (J4) In the second embodiment described above, the opening area of ​​first opening 51A is the largest, and the opening areas of second opening 52A, third opening 53A, and fourth opening 54A gradually decrease toward central axis CX in that order. Instead of this, for example, the opening areas of the first opening and second opening, and the opening areas of the third opening and fourth opening may be the same, and the opening areas of the third opening and fourth opening may be smaller than the opening areas of the first opening and second opening.

[0090] (J5) In each of the above embodiments, the cross-sectional shapes of the opening and the support can be changed as appropriate to a perfect circle, a rectangle, an ellipse, a polygon, etc. Furthermore, as long as the support can be inserted into the opening, the cross-sectional shapes of the support and the opening may be different.

[0091] (J6) In the above first to fourth embodiments, the pillars 31, 32 are integrally formed with the top cover 15 of the housing case 11, but they may be separate bodies. For example, the housing case 11 and the pillars 31, 32 may be manufactured separately and bonded together, after which the ferrite plate 13 and the coil substrate 14 are assembled. In addition, the pillars 31, 32 may be integral with the bottom cover 16 of the housing case 11, or may be integrally formed with the aluminum plate 12.

[0092] (J7) In the above first to fourth embodiments, the coil unit 10 is described as being on the power transmitting side, but the present disclosure may be applied to a coil unit on the power receiving side. Also, in the fifth to ninth embodiments, the coil units 80, 80a, 80b, and 80c are described as being on the power receiving side, but the present disclosure may be applied to a coil unit on the power transmitting side.

[0093] (J8) In the fourth embodiment, the openings 71A, 72A, 73A, and 74A may be gradually narrowed from the outer edge toward the central axis CX so that the opening area becomes smaller, or may be narrowed in stages.

[0094] (J9) In the fourth embodiment, the slit-shaped openings 71A, 72A, 73A, and 74A may be connected at the center.

[0095] (J10) In the above fifth to ninth embodiments, the components of the support 90 (support member 91, support member 91a, spacer member 93, protrusion 861, protrusion 861c) are joined to the upper cover 85 or the lower cover 86, 86a by the screws 98, 99, but the present disclosure is not limited to this. The bonding may be performed by a method.

[0096] (J11) In the sixth to eighth embodiments, the spacer member 93 may be omitted. In such a configuration, the length of the protruding portions 861, 861c in the stacking direction may be increased so that the upper ends of the protruding portions 861, 861c contact the lower surface of the top cover 85. In such a configuration, the support pillars 90 are composed of only the protruding portions 861, 861c. In such a configuration, only some of the multiple support pillars 90 are composed of only the protruding portions 861, 861c, and the other support pillars 90 may have the configuration of the sixth to eighth embodiments.

[0097] (J12) In the side wall portion 862 of the seventh embodiment, the arrangement direction of the carbon fibers CF was approximately parallel to the up-down direction (Z-axis direction), but the present disclosure is not limited to this. In the side wall portion 862, at least a part of the carbon fibers CF may be arranged along a direction that satisfies a predetermined angle condition. The "predetermined angle condition" means a condition that the angle between the average direction of at least a part of the carbon fibers CF and the direction of the magnetic flux B1 generated by the coil 84 (hereinafter simply referred to as the "magnetic flux direction") is 45° or less. The above-mentioned "average direction" means the average direction in the length direction of each carbon fiber CF. When the angle between the average direction of at least a part of the carbon fibers CF and the magnetic flux direction generated by the coil 84 is 45° or less, the generation of eddy currents can be suppressed compared to when the angle is greater than 45°. Similarly, in the protruding end 863 of the seventh embodiment, the carbon fibers CF are approximately parallel to the direction from the outer edge of the magnetic material plate 83 toward the center of the magnetic material plate 83 and the opposite direction, but the present disclosure is not limited to this. In the protruding end 863, at least a part of the carbon fibers CF may be arranged along a direction that satisfies a predetermined angle condition. The "predetermined angle condition" in this case is the same as above. That is, it means the condition that "the angle between the average direction of at least a part of the carbon fibers CF and the magnetic flux direction of the magnetic flux B1 generated by the coil 84 is 45° or less." That is, generally, in the protrusion 861, at least a portion of the carbon fibers CF are arranged along a direction that satisfies a predetermined angle condition, and the above-mentioned angle range is such that the angle between the average direction of at least a portion of the carbon fibers CF and the magnetic flux direction of the magnetic flux generated by the coil 84 is 45° or less. Any configuration may be applied to the coil unit of the present disclosure.

[0098] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in each embodiment corresponding to the technical features in the embodiment described in the Summary of the Invention column can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. For example, the fifth embodiment and the eighth embodiment may be combined, and the external shape of the protrusion 861c of the eighth embodiment may be applied to the support member 91 of the fifth embodiment. Specifically, the support member 91 may be configured to have a tapered external shape in which the cross-sectional area perpendicular to the stacking direction becomes smaller as it moves upward along the stacking direction, in other words, as it moves from the coil 84 to the magnetic material plate 83 along the stacking direction. Moreover, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0099] (Form 1) A coil unit for use in a non-contact power supply system (300), A ferrite plate (13); a coil substrate (14) on which a coil (112) for transmitting or receiving AC power is mounted; a storage case (11) that stores the ferrite plate and the coil substrate in a stacked state in a stacking direction; a plurality of support forming parts (21, 22, 23, 24) each having a support (31, 32) inserted into an opening (41, 42) penetrating the ferrite plate and the coil substrate in the stacking direction, and each of which holds a space in the stacking direction within the housing case, the plurality of support forming parts (21, 22, 23, 24) being provided along a flow direction of a magnetic flux flowing from an outer edge of the ferrite plate toward a central axis, the magnetic flux being generated by the coil when transmitting or receiving the AC current, and being provided spaced apart from each other around the central axis as viewed in the stacking direction; A coil unit comprising: (Form 2) The coil unit of embodiment 1, wherein an opening area of ​​the opening on the central axis side as viewed in the stacking direction is smaller than an opening area of ​​the opening on the outer edge side as viewed in the stacking direction. (Form 3) At least one of the plurality of support pillar forming portions has a plurality of the support pillars inserted into a plurality of the openings, The coil unit according to embodiment 1 or 2, wherein the intervals at which the openings are formed on the central axis side are wider than the intervals at which the openings are formed on the outer edge side. (Form 4) The coil unit according to any one of modes 1 to 3, wherein the plurality of support pillar forming portions are provided in point symmetry with respect to the central axis as a center of symmetry when viewed in the stacking direction. (Form 5) The coil unit according to any one of the first to fourth embodiments, wherein the cross-sectional shape of the support in a plane perpendicular to the stacking direction is the same as the cross-sectional shape of the opening in the plane perpendicular to the stacking direction. (Form 6) The coil unit according to any one of the first to fifth embodiments, wherein the support pillar is inserted through the opening, extends in the stacking direction to an inner wall of the housing case, and is formed integrally with the housing case. (Form 7) A coil unit for use in a contactless power supply system, A magnetic material plate; A coil for transmitting or receiving AC power; a housing case that houses the magnetic material plate and the coil in a stacked state in a stacking direction, the housing case having a first cover member and a second cover member that can be separated in the stacking direction; a plurality of support pillar forming parts having supports for connecting the first cover member and the second cover member, penetrating the magnetic material plate and the coil in the stacking direction from the first cover member to the second cover member, the support pillar forming parts being provided along a flow direction of magnetic flux generated by the coil when transmitting or receiving the AC power, the magnetic flux flowing from the outer edge of the magnetic material plate toward the central axis or from the central axis toward the outer edge, and being provided spaced apart from each other around the central axis when viewed in the stacking direction; A coil unit comprising: (Form 8) In the coil unit according to aspect 7, A coil unit, wherein at least a portion of the multiple pillars included in the multiple pillar forming portions are pillar members, and include a pillar member having one end in the stacking direction joined to the first cover member and the other end joined to the second cover member. (Form 9) The coil unit according to aspect 7 or 8, a metallic shield plate disposed on the opposite side of the magnetic material plate from the coil and shielding at least a part of the magnetic flux; and a metallic spacer member. the coil, the magnetic material plate, and the shield plate are laminated in the lamination direction, the first cover member is formed of a material that is at least non-magnetic among magnetic and conductive materials, and has a protruding portion that is in contact with the coil, protrudes along the stacking direction, and penetrates the coil and the magnetic material plate in the stacking direction; The second cover member is in contact with the shield plate, the spacer member is disposed in contact with the protruding portion in the stacking direction and penetrating the shield plate in the stacking direction, A coil unit, wherein at least a portion of the plurality of pillars included in the plurality of pillar forming portions are constituted by the protrusion and the spacer member. (Form 10) In the coil unit according to aspect 9, the first cover member is made of a material containing conductive fibers, A coil unit, wherein at least a portion of the fibers in the protrusion are arranged along the direction of magnetic flux generated in the protrusion by the coil. (Form 11) In the coil unit according to the ninth or tenth aspect, The protrusion has a tapered external shape in which a cross-sectional area perpendicular to the stacking direction decreases from the coil toward the magnetic material plate along the stacking direction. (Form 12) In the coil unit according to aspect 8, The support member has a tapered external shape in which a cross-sectional area perpendicular to the stacking direction decreases from the coil toward the magnetic material plate along the stacking direction. (Form 13) In the coil unit according to any one of the seventh to twelfth aspects, A coil unit, wherein, of the multiple pillars included in the multiple pillar forming portions, the pillars arranged at positions where the magnetic flux generated by the coil is greater than a predetermined threshold value are formed from a non-conductive material, and the pillars arranged at positions where the magnetic flux generated by the coil is equal to or less than the threshold value are formed from a metal. [Explanation of symbols]

[0100] 10...coil unit, 11...accommodating case, 12...aluminum plate, 13...ferrite plate, 14...coil substrate, 15...upper cover, 16...lower cover, 21, 22, 23, 24...support forming portion, 31, 32...support, 41, 42...opening, 51A, 52A, 53A, 54A...opening, 61A, 62A, 63A, 64A...opening, 71A, 72A, 73A , 74A...opening, 100...power transmitter, 110...power transmitter resonant circuit, 112...power transmitter coil, 116...first capacitor, 120...power transmitter circuit, 130...power supply circuit, 200...vehicle, 205...power receiver, 210...power receiver resonant circuit, 212...power receiver coil, 216...second capacitor, 220...power receiver circuit, 230...battery, 300...non-contact power supply system, CX...central axis

Claims

1. A coil unit for use in a non-contact power supply system (300), A magnetic material plate (13); a coil substrate (14) on which a coil (112) for transmitting or receiving AC power is mounted; a storage case (11) for storing the magnetic material plate and the coil substrate in a stacked state in a stacking direction; a plurality of support pillar forming parts (21, 22, 23, 24) each having a support pillar (31, 32) inserted into an opening (41, 42) penetrating the magnetic material plate and the coil substrate in the stacking direction, and which hold a space in the stacking direction within the housing case, the support pillar forming parts being provided along a flow direction of a magnetic flux flowing from an outer edge of the magnetic material plate toward a central axis, the magnetic flux being generated by the coil when transmitting or receiving the AC power, and being provided spaced apart from each other around the central axis as viewed in the stacking direction; Equipped with A coil unit, wherein an opening area of ​​the opening on the central axis side as viewed in the stacking direction is smaller than an opening area of ​​the opening on the outer edge side as viewed in the stacking direction.

2. At least one of the plurality of support pillar forming portions has a plurality of the support pillars inserted into a plurality of the openings, The coil unit according to claim 1 , wherein an interval between the openings formed on the central axis side is wider than an interval between the openings formed on the outer edge side.

3. The coil unit according to claim 1 , wherein the plurality of support pillar forming portions are provided in point symmetry with respect to the central axis as viewed in the stacking direction.

4. The coil unit according to claim 1 , wherein a cross-sectional shape of the support in a plane perpendicular to the stacking direction is the same as a cross-sectional shape of the opening in the plane perpendicular to the stacking direction.

5. The coil unit according to any one of claims 1 to 4, wherein the support pillar is inserted through the opening, extends in the stacking direction to an inner wall of the accommodating case, and is formed integrally with the accommodating case.

6. A coil unit for use in a contactless power supply system, A magnetic material plate; A coil for transmitting or receiving AC power; a housing case that houses the magnetic material plate and the coil in a stacked state in a stacking direction, the housing case having a first cover member and a second cover member that can be separated in the stacking direction; a plurality of support pillar forming parts having supports for connecting the first cover member and the second cover member, penetrating the magnetic material plate and the coil in the stacking direction from the first cover member to the second cover member, the support pillar forming parts being provided along a flow direction of magnetic flux generated by the coil when transmitting or receiving the AC power, the magnetic flux flowing from the outer edge of the magnetic material plate toward the central axis or from the central axis toward the outer edge, and being provided spaced apart from each other around the central axis when viewed in the stacking direction; Equipped with A coil unit, wherein, of the multiple pillars included in the multiple pillar forming portions, the pillars arranged at positions where the magnetic flux generated by the coil is greater than a predetermined threshold value are formed from a non-conductive material, and the pillars arranged at positions where the magnetic flux generated by the coil is equal to or less than the threshold value are formed from a metal.

7. The coil unit according to claim 6, A coil unit, wherein at least a portion of the multiple pillars included in the multiple pillar forming portions are pillar members, and include a pillar member having one end in the stacking direction joined to the first cover member and the other end joined to the second cover member.

8. The coil unit according to claim 6, a metallic shield plate disposed on the opposite side of the magnetic material plate from the coil and shielding at least a part of the magnetic flux; and a metallic spacer member. the coil, the magnetic material plate, and the shield plate are laminated in the lamination direction, the first cover member is formed of a material that is at least non-magnetic among magnetic and conductive materials, and has a protruding portion that is in contact with the coil, protrudes along the stacking direction, and penetrates the coil and the magnetic material plate in the stacking direction; The second cover member is in contact with the shield plate, the spacer member is disposed in contact with the protruding portion in the stacking direction and penetrating the shield plate in the stacking direction, A coil unit, wherein at least a portion of the plurality of pillars included in the plurality of pillar forming portions are constituted by the protrusion and the spacer member.

9. The coil unit according to claim 8, the first cover member is made of a material containing conductive fibers, A coil unit, wherein at least a portion of the fibers in the protrusion are arranged along the direction of magnetic flux generated in the protrusion by the coil.

10. The coil unit according to claim 8, The protrusion has a tapered external shape in which a cross-sectional area perpendicular to the stacking direction decreases from the coil toward the magnetic material plate along the stacking direction.

11. The coil unit according to claim 7, The support member has a tapered external shape in which a cross-sectional area perpendicular to the stacking direction decreases from the coil toward the magnetic material plate along the stacking direction.

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