Contactless power supply coil, power transmission device, power receiving device, power transmission system, and method for manufacturing contactless power supply coil

Abstract

To improve the withstand voltage while suppressing an increase in the electrical resistance of a coil.SOLUTION: A contactless power supply coil 10 includes a planar coil 20 formed by winding a conductor wire 22 in a planar manner, and a magnetic body 30. Ends 24, 26 of the coil 20 serve as electrode connection portions. The coil 20, excluding the ends 24, 26, is embedded in the magnetic body 30 and is surrounded by the magnetic body 30. In at least one cross section perpendicular to the axis of the conductor wire 22, the spaces between adjacent conductor wires 22 in the portion of the coil 20 where the conductor wires 22 are lined up next to each other are filled with the magnetic body 30. Pores 40 exist in the magnetic body 30 between the adjacent conductor wires 22.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a coil for contactless power transfer, a power transmitting device, a power receiving device, a power transfer system, and a method for manufacturing a coil for contactless power transfer. [Background technology]

[0002] It is known that when the conductors of a coil come close to each other, the electrical resistance increases due to the proximity effect. In coils with many turns, the proximity effect adds up, further increasing the electrical resistance. Increased electrical resistance in a coil leads to heat generation, which in turn results in energy loss and a decrease in the Q value, which indicates coil performance. Various configurations have been considered to suppress this increase in electrical resistance in coils.

[0003] For example, Patent Document 1 discloses a magnetically coated coil. This magnetically coated coil includes a flat wire coil wound with a flat wire and a magnetic coating that coats both sides of the flat wire in the width direction.

[0004] Patent Document 2 discloses a coil for contactless power supply, which includes a spirally wound flat coil and a magnetic wall disposed in the gap between the coil conductor of any winding of the coil and the coil conductor of the adjacent winding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-9177 [Patent Document 2] Patent Publication No. 2021-27112 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the magnetically coated coil of Patent Document 1, both the upper and lower sides of the flat wire in the width direction are exposed and not covered by the magnetic coating, which causes leakage magnetic fields from the exposed parts of the flat wire, leading to an increase in the electrical resistance of the flat wire coil.

[0007] In the contactless power supply coil of Patent Document 2, one axial surface (top surface) of the coil conductor is exposed and not covered by a magnetic wall, which causes a leakage magnetic field to be generated from the exposed axial surface (top surface) of the coil conductor, leading to an increase in the electrical resistance of the coil.

[0008] Furthermore, in the magnetically coated coils of Patent Documents 1 and 2, the spacing between the conductor wires of the coil is relatively small, which may result in poor insulation. In the magnetically coated coil of Patent Document 2, magnetic walls are disposed between the conductor wires of the coil, but the magnetic material generally has a relatively low electrical resistance, which may result in poor insulation. The present disclosure has been made in view of the above-described circumstances, and aims to provide a technique that can improve the withstand voltage while suppressing an increase in the electrical resistance of a coil. The present disclosure can be realized in the following forms. [Means for solving the problem]

[0009] [1] A planar coil formed by winding a conductor in a planar shape; A contactless power supply coil including a magnetic body, The ends of the coil are electrode connection portions, the coil, excluding the end portion, is embedded in the magnetic body, and is surrounded by the magnetic body; In at least one cross section perpendicular to the axis of the conductor, the spaces between adjacent conductors in a portion of the coil where the conductors are arranged side by side are filled with the magnetic material, Pores are present in the magnetic body between adjacent conductive wires. Coil for contactless power supply.

[0010] According to the contactless power transfer coil of [1] above, the coil, excluding the ends, is disposed within a magnetic body, and in at least one cross section perpendicular to the axis of the conductor wires, the spaces between adjacent conductor wires in the coil are filled with magnetic body. This configuration makes it difficult for the magnetic field generated from the conductor wires of the coil to leak from the magnetic body, thereby suppressing the occurrence of a proximity effect between adjacent conductor wires. This suppresses an increase in the electrical resistance of the coil. Furthermore, the contactless power transfer coil is configured such that pores exist in the magnetic body between adjacent conductor wires. This configuration allows the presence of pores with a relatively high withstand voltage between adjacent conductor wires of the coil, thereby improving the withstand voltage between the adjacent conductor wires. This therefore suppresses an increase in the electrical resistance of the coil while improving the withstand voltage.

[0011] [2] The coil for contactless power supply according to [1], wherein the minimum distance between adjacent conductors in the adjacently arranged portion is 0.3 mm or more.

[0012] According to the coil for contactless power supply of [2] above, a sufficient gap can be provided between adjacent conductor wires, and the withstand voltage between adjacent conductor wires of the coil can be further improved.

[0013] [3] The contactless power supply coil according to [1] or [2], wherein the average diameter of pores present in the magnetic body is 100 μm or less.

[0014] According to the contactless power supply coil of [3] above, it is easy to suppress the proximity effect occurring between adjacent conductors, and it is easy to suppress an increase in the electrical resistance of the coil.

[0015] [4] A coil for contactless power supply described in any one of [1] to [3], wherein in the adjacently arranged portions, in at least one cross section perpendicular to the axis of the conductor, a line segment connecting the centers of gravity of adjacent conductors is contained within the area where the magnetic material exists.

[0016] According to the contactless power supply coil of [4] above, it becomes easier to suppress the proximity effect occurring between adjacent conductors.

[0017] [5] The coil for contactless power supply according to any one of [1] to [4], wherein the magnetic body includes a resin and soft magnetic particles.

[0018] According to the contactless power supply coil of [5] above, the electrical resistance and withstand voltage of the coil can be easily adjusted by selecting the resin and soft magnetic particles that make up the magnetic body.

[0019] [6] The coil for contactless power supply according to any one of [1] to [5], wherein the dielectric strength of the magnetic body is 200 V / m or more.

[0020] According to the coil for contactless power supply described above in [6], it is possible to prevent short circuits between the conductor wires of the coil.

[0021] [7] A coil for contactless power supply described in any one of [1] to [6], wherein the coil is in the form of a ring and there is an area inside the ring where the magnetic material is not present.

[0022] According to the contactless power supply coil of [7] above, it becomes easy to generate a magnetic force directed from the inside of the coil ring to the outside.

[0023] [8] A coil for contactless power supply described in any one of [1] to [7], which is provided with a magnetic member on one side of the magnetic body, and the complex relative permeability of the magnetic member is greater than the complex relative permeability of the magnetic body.

[0024] According to the coil for contactless power supply described above in [8], the inductance of the coil can be improved.

[0025] [9] A coil for contactless power supply described in any one of [1] to [8], which is provided with a magnetic member and an electromagnetic shielding member, in that order, on one side of the magnetic body, and the complex relative permeability of the magnetic member is greater than the complex relative permeability of the magnetic body.

[0026] According to the contactless power supply coil of [9] above, electromagnetic noise that may be generated from the coil can be reflected by the electromagnetic shielding member, and leakage to the outside can be suppressed.

[0027]

[10] A power transmission device including a contactless power supply coil according to any one of [1] to [9].

[0028] According to the power transmission device of

[10] above, it is possible to improve the withstand voltage while suppressing an increase in the electrical resistance of the coil during power transmission.

[0029]

[11] A power receiving device comprising a contactless power supply coil according to any one of [1] to [9].

[0030] According to the power receiving device of the above

[11] , it is possible to improve the withstand voltage while suppressing an increase in the electrical resistance of the coil when receiving power.

[0031]

[12] A power transmission system comprising a power transmitting device and a power receiving device, wherein at least one of the power transmitting device and the power receiving device comprises a contactless power supply coil described in any one of [1] to [9].

[0032] According to the power transmission system of

[12] above, in at least one of the power transmitting device and the power receiving device, it is possible to improve the withstand voltage while suppressing an increase in the electrical resistance of the coil.

[0033]

[13] A method for manufacturing a coil for contactless power supply including a planar coil formed by winding a conductor wire in a planar shape and a magnetic body, The coil is disposed on one surface of a first sheet containing a magnetic material; Filling the spaces between the adjacent conductor wires in the coil with a paste containing a magnetic material and containing air bubbles; Furthermore, a second sheet containing a magnetic material is placed on the opposite side of the coil from the first sheet, Thereafter, the magnetic material-containing paste is hardened, thereby integrating the hardened magnetic material-containing paste with the first sheet and the second sheet to form the magnetic body. Manufacturing method for contactless power supply coils.

[0034] According to the manufacturing method of a contactless power transfer coil described in

[13] above, it is possible to manufacture a contactless power transfer coil in which the coil is embedded in a magnetic body and is surrounded by the magnetic body. This makes it possible to manufacture a contactless power transfer coil in which the magnetic field generated from the conductor wire of the coil is less likely to leak from the magnetic body and the proximity effect between adjacent conductor wires can be suppressed. Furthermore, since the magnetic material-containing paste containing air bubbles that is filled between adjacent conductor wires in the coil hardens to become a magnetic body, it is possible to realize a contactless power transfer coil in which pores exist in the magnetic body between adjacent conductor wires. This results in a contactless power transfer coil in which the withstand voltage between adjacent conductor wires of the coil is improved. Therefore, it is possible to manufacture a contactless power transfer coil in which the withstand voltage can be improved while suppressing an increase in the coil's electrical resistance. [Effects of the Invention]

[0035] The present disclosure can provide a technique that can improve the withstand voltage while suppressing an increase in the electrical resistance of a coil. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is an explanatory diagram illustrating a power transmission system according to an embodiment of the present disclosure. [Figure 2] 4 is a cross-sectional view illustrating a magnetic field generated between a coil for contactless power supply on the power transmission side and a coil for contactless power supply on the power receiving side. FIG. [Figure 3] FIG. 2 is a perspective view of a contactless power supply coil. [Figure 4] FIG. 2 is a plan view of a contactless power supply coil. [Figure 5] FIG. 2 is a side cross-sectional view of a contactless power supply coil. [Figure 6] FIG. 6 is a cross-sectional side view of the contactless power supply coil taken at a position different from that of FIG. 5. [Figure 7] FIG. 7 is an enlarged view showing a part of the cross-sectional view of FIG. 6. [Figure 8] FIG. 8 is an explanatory diagram illustrating a magnetic field in the cross section shown in FIG. [Figure 9] 10A to 10C are explanatory diagrams illustrating a manufacturing process of the contactless power supply coil. [Figure 10]10A and 10B are explanatory diagrams illustrating the manufacturing process of the contactless power supply coils of Comparative Examples 5 and 6. FIG. [Figure 11] 10 is an explanatory diagram illustrating a magnetic field generated between a coil for contactless power supply on the power transmission side and a coil for contactless power supply on the power receiving side in the second embodiment. FIG. [Figure 12] FIG. 12 is a side cross-sectional view of the contactless power supply coil on the power transmission side of FIG. [Figure 13] 10 is an explanatory diagram illustrating a magnetic field generated between a coil for contactless power supply on the power transmission side and a coil for contactless power supply on the power receiving side in the third embodiment. FIG. [Figure 14] FIG. 14 is a side cross-sectional view of the contactless power supply coil on the power transmission side of FIG. [Figure 15] FIG. 10 is a perspective view of a contactless power supply coil according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0037] The present disclosure will be described in detail below. In this specification, when a numerical range is indicated using "-", it is intended to include both the lower limit and the upper limit unless otherwise specified. For example, the expression "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less". In addition, in this specification, the upper limit and lower limit of each numerical range can be combined in any way.

[0038] First Embodiment 1. Power transmission system 100 Fig. 1 shows an example of a power transmission system 100 according to the first embodiment. The power transmission system 100 is configured as, for example, a system for supplying power wirelessly (contactlessly) to an electric vehicle, a system for supplying power to a mobile terminal (such as a smartphone), or the like. As shown in Fig. 1, the power transmission system 100 includes a power transmitting device 110 and a power receiving device 120. In the power transmission system 100, power is supplied wirelessly (contactlessly) from the power transmitting device 110 to the power receiving device 120.

[0039] The power transmission device 110 has the contactless power supply coil 10 and a conversion unit 112. The conversion unit 112 is configured as, for example, an inverter. The conversion unit 112 receives power from, for example, a power source (commercial power source or the like) 114, converts the voltage and frequency, and supplies the power to the contactless power supply coil 10.

[0040] The power receiving device 120 has a contactless power transfer coil 10 and a conversion unit 122. The conversion unit 122 is configured as, for example, an inverter, a rectifier, or the like. The conversion unit 122 is supplied with power generated in the contactless power transfer coil 10, converts AC to DC, and supplies the power to a battery 124. The conversion unit 122 is also supplied with power generated in the contactless power transfer coil 10, converts the voltage and frequency, and supplies the power to a motor 126.

[0041] When power is supplied wirelessly (contactlessly) from the power transmitting device 110 to the power receiving device 120, a high-frequency current of a predetermined frequency is supplied from the conversion unit 112 in the power transmitting device 110 to the contactless power supply coil 10. As shown in Fig. 2 , a magnetic field is generated in the contactless power supply coil 10 of the power transmitting device 110, and a high-frequency current is generated in the contactless power supply coil 10 of the power receiving device 120 due to the influence of this magnetic field. The conversion unit 122 of the power receiving device 120 converts this high-frequency current and supplies it to the battery 124 and the motor 126.

[0042] 2. Contactless power supply coil 10 2 to 4 show an example of the contactless power supply coil 10 of the first embodiment. The contactless power supply coil 10 includes a coil 20 and a magnetic body 30.

[0043] 2-1. Coil 20 The coil 20 is a planar coil formed by winding a conductor 22 in a plane. The coil 20 has a spiral shape (a planar curve wound in a spiral shape) wound around a central axis C (see Figures 3 and 4). The conductors 22 are arranged so that they gradually move away from the central axis C as they move radially outward from the central axis C. The coil 20 is wound to form a rectangle (more specifically, a square with rounded corners). The coil 20 has a ring shape as a whole. The coil 20 has a shape in which the conductor 22 is wound, for example, nine times.

[0044] The coil 20 is made of a conductive material, such as aluminum (Al), an aluminum (Al) alloy, copper (Cu), or a copper (Cu) alloy.

[0045] The coil 20 is a rectangular wire. That is, the cross-sectional shape of the coil 20 (the cross-sectional shape perpendicular to the axis of the conductive wire 22) is rectangular (more specifically, a rectangle whose length is in the radial direction relative to the central axis C). The coil 20 is, for example, a so-called edgewise coil.

[0046] The size (thickness) of the conductor 22 in a direction parallel to the central axis C is, for example, 0.4 mm to 1.0 mm, e.g., 0.6 mm. The size (width) of the conductor 22 in a radial direction (a direction perpendicular to the central axis C) is, for example, 5 mm to 20 mm, e.g., 8 mm or 16 mm.

[0047] The spacing between adjacent conductors 22 in the portion of the coil 20 where the conductors 22 are lined up next to each other is, for example, constant throughout the entire coil 20. The minimum distance between adjacent conductors 22 (the minimum distance between opposing side surfaces) is preferably 0.3 mm or more. The minimum distance between adjacent conductors 22 is, for example, 0.2 mm or more and 6 mm or less, e.g., 0.2 mm, 0.3 mm, 1.4 mm, 2.5 mm, or 5 mm.

[0048] The ends 24, 26 of the coil 20 (see Figures 3 and 5) serve as electrode connection sections. The ends 24, 26 of the coil 20 are connected to, for example, the conversion sections 112, 122, etc. The inner end 24 extends in a direction along the central axis C from the winding portion of the coil 20 closest to the central axis C. The outer end 26 extends in a direction along the central axis C from the winding portion of the coil 20 closest to the central axis C. The ends 24, 26 extend on the same side (upper side in Figures 3 and 5) with respect to the plane on which the conductive wire 22 is wound. The ends 24, 26 are bent, for example at a right angle, with respect to the rest of the conductive wire 22.

[0049] The AC resistance of the coil 20 is preferably 30 mΩ or more and 200 mΩ or less.

[0050] 2-2.Magnetic material 30 The magnetic body 30 integrally covers the periphery of the coil 20. The coil 20, excluding the ends 24 and 26, is embedded in the magnetic body 30, and is thereby surrounded by the magnetic body 30. In at least one cross section perpendicular to the axis of the conductor 22 (for example, the cross sections shown in FIGS. 5 and 6), the spaces between adjacent conductor wires 22 in the portion of the coil 20 where the conductor wires 22 are lined up next to each other are filled with the magnetic body 30. More specifically, in all cross sections perpendicular to the axis of the conductor wire 22 (all cross sections including the cross sections shown in FIGS. 5 and 6), the spaces between adjacent conductor wires 22 in the portion of the coil 20 where the conductor wires 22 are lined up next to each other are filled with the magnetic body 30. In other words, the magnetic body 30 is sandwiched between adjacent conductor wires 22.

[0051] The magnetic body 30 contains a resin and soft magnetic particles. The soft magnetic particles are preferably uniformly dispersed within the magnetic body 30. Examples of resins include natural rubber, butyl rubber, nitrile rubber, silicone, acrylic, and polyimide. Among these, silicone is particularly preferred due to its ease of filler mixing and high heat resistance. When silicone is used, its molecular weight is preferably 20,000 or more.

[0052] Examples of the soft magnetic particles include Ni-Zn ferrite, Mn-Zn ferrite, magnetite, Fe-Si-B alloy, Fe-Si-B-Cr alloy, Fe-Si alloy, Fe-Si-Cr alloy, Sendust, Permalloy, etc. From the viewpoint of suppressing the electric resistance of the coil 20 when the non-contact power supply coil 10 is used with an alternating current of about 85 kHz, these materials are preferable. When using spherical alloy-based fillers as the soft magnetic particles, considering the loss due to eddy currents, the particle diameter is preferably 10 μm or more and 50 μm or less.

[0053] In the adjacent and juxtaposed portions of the conductor 22 of the coil 20, in at least one cross-section perpendicular to the axis of the conductor 22, the line segment connecting the centers of gravity of the adjacent conductors 22 is within the existence region of the magnetic body 30. For example, as shown in FIG. 7, the line segment S connecting the centers of gravity G of the adjacent conductors 22 is within the existence region of the magnetic body 30. That is, the line segment S is not exposed outside the magnetic body 30.

[0054] Inside the loop of the coil 20, there is a non-existence region (opening 30A) of the magnetic body 30. That is, the magnetic body 30 is not embedded inside the loop of the coil 20.

[0055] As shown in FIG. 6, in a cross-section having a shape symmetric with respect to the central axis C, let the width in the direction perpendicular to the central axis C of the coil 20 be L1, and the width in the direction perpendicular to the central axis C of the non-contact power supply coil 10 (magnetic body 30) be L2. It is preferable that L1 and L2 satisfy 1 < L2 / L1 < 1.1. Also, it is preferable that the magnetic body 30 protrudes 5 mm or more and 10 mm or less from the outermost edge of the coil 20.

[0056] As shown in FIG. 5, the magnetic body 30 has holes 32 and 34 for pulling out the ends 24 and 26 of the coil 20. The holes 32 and 34 extend in the direction along the central axis C.

[0057] As shown in Fig. 7, pores (air bubbles) 40 exist in the magnetic body 30 between adjacent conductive wires 22. The pores 40 may be isolated pores that are not connected to one another, or may be interconnected open pores. It is preferable that the pores 40 exist so as to be uniformly dispersed in the magnetic body 30 between adjacent conductive wires 22. It is preferable that the pores 40 do not exist in any part of the magnetic body 30 other than between the adjacent conductive wires 22 (the outer edge part of the magnetic body 30).

[0058] The average diameter of the pores 40 present in the magnetic body 30 is preferably 100 μm or less. The average diameter of the pores 40 is, for example, 10 μm or more and 100 μm or less, e.g., 50 μm. The average diameter of the pores 40 can be determined by observing the magnetic body 30 between adjacent conductive wires 22 in a cross section perpendicular to the axis of the conductive wires 22 (a cross section cut along a cutting plane including the central axis C) using a cross-sectional SEM (field of view 200 μm × 200 μm) after CP treatment. The average diameter of the pores 40 is then calculated as the average of the maximum diameters of the cross sections of all pores 40 within the field of view.

[0059] The dielectric strength of the magnetic body 30 is preferably 200 V / m or more. Even when a voltage of, for example, 100 V to 500 V is applied to the coil 20, short circuits between the conductor wires 22 can be prevented.

[0060] 2-3. Function of the non-contact power supply coil 10 2 shows the flow of magnetic fields generated in the contactless power supply coil 10 of the power transmitting device 110 and the contactless power supply coil 10 of the power receiving device 120. When a high-frequency current is passed through the contactless power supply coil 10 of the power transmitting device 110, the direction of the arrows switches rapidly.

[0061] 8 shows the flow of the magnetic field generated in the contactless power transfer coil 10. Because the magnetic field is generated within the magnetic material 30, which has a relatively high magnetic permeability, the conductor 22 is protected from the magnetic field. This makes it possible to suppress the occurrence of a proximity effect between adjacent conductors. In addition, because the magnetic fields generated by the conductors 22 are added together, the magnetic field generated by the coil 20 becomes stronger.

[0062] In the planar coil 20, the spacing between the conductors 22 is narrow, and insulation must be ensured despite the presence of the magnetic material 30. For example, in a resonant wireless power transfer system, a voltage of, for example, 1 kV or more is repeatedly applied instantaneously to the coils 20 on the power transmitting and receiving sides. Although it depends on the composition, soft magnetic particles often have low electrical resistance, and even if they are mixed with an insulating resin to achieve a dielectric strength (voltage resistance) of several hundred V / mm to 1 kV / mm, this is not sufficient. On the other hand, air has a dielectric strength of about 3 kV / mm, and the dielectric strength can be improved by incorporating pores 40 into the magnetic material 30.

[0063] However, the inclusion of pores 40 reduces the number of soft magnetic particles present between the conductor wires 22, resulting in a decrease in the complex relative permeability of the magnetic body 30. For example, when the soft magnetic particle content is 57 vol%, the complex relative permeability is around 10. On the other hand, when the soft magnetic particle content is reduced to 50 vol%, the complex relative permeability is around 8, which does not result in a significant decrease and the impact is minor. Even if the pores 40 are contained at around 7 vol%, the disadvantage is small.

[0064] 3. Manufacturing method of the non-contact power supply coil 10 A method for manufacturing a contactless power transfer coil according to the present disclosure will be described with reference to FIG. 9 . In this method for manufacturing a contactless power transfer coil, first, coil 20 is placed on one side of first sheet 51 containing a magnetic material. First sheet 51 has an opening 51A at its center. Next, spaces between adjacent conductive wires 22 in coil 20 are filled with air-bubbled magnetic material-containing paste 52. Furthermore, second sheet 53 containing a magnetic material is placed on the side of coil 20 opposite first sheet 51. Thereafter, magnetic material-containing paste 52 is hardened, and the hardened magnetic material-containing paste 52 is integrated with first sheet 51 and second sheet 53 to form magnetic body 30. Each step will be described in detail below.

[0065] First, a magnetic material-containing paste 52 (hereinafter simply referred to as paste 52) is prepared. A magnetic powder (e.g., Fe-Si-B amorphous alloy powder with an average particle size of approximately 5 μm-10 μm) is added to a resin material (e.g., polydimethylsiloxane with a molecular weight of approximately 50,000). For example, the magnetic powder is added so that the final amount added is 57 vol% to obtain a mixture. For example, after the mixture is subjected to blade stirring and roll mixing, a silane coupling agent and a platinum catalyst for the curing reaction are added, and the mixture is subjected to blade stirring again. A hollow resin powder or hollow ceramic powder may be added to the mixture to adjust the porosity. For example, a cross-linking agent (e.g., cross-linking polydimethylsiloxane with a molecular weight of 10,000 or less) is added to the stirred mixture, and the mixture is subjected to blade stirring and vacuum degassing again to obtain a magnetic material-containing paste 52 containing bubbles.

[0066] The viscosity of the paste 52 is preferably 50 Pa·s to 1000 Pa·s at 21° C. This can prevent the paste 52 from flowing out during the steps of producing the first sheet 51 and the second sheet 53, which will be described later, and during the step of injecting the paste 52, which will be described later. In addition, when pores are mixed into the paste 52, this can prevent bubbles from breaking.

[0067] Next, a first sheet 51 and a second sheet 53 are prepared. The paste 52 is thoroughly degassed in advance to eliminate any pores. The paste 52 is placed in a green sheet molding machine and molded to a thickness of 400 μm. The resulting sheet molding is heated to obtain the first sheet 51 containing the magnetic material. The heating is performed, for example, at a temperature of 100°C or less for 1 to 5 hours. The first sheet 51 has adhesive properties. A similar process is used to obtain the second sheet 53 containing the magnetic material.

[0068] 9(A), the coil 20 is disposed on one surface of the first sheet 51 containing a magnetic material. The coil 20 is attached to the one surface of the first sheet 51 and integrated therewith.

[0069] 9(B), the gaps between adjacent conductor wires 22 in the coil 20 are filled with a magnetic material-containing paste 52 containing air bubbles. The paste 52, which has been stirred to incorporate air pores in advance, is injected with a syringe into the gaps between adjacent conductor wires 22. Thereafter, vacuum degassing is performed for one minute or less to remove relatively large air pores.

[0070] Next, as shown in FIG. 9(C), the excess paste 52 is removed using a scraper to make the surface flat.

[0071] Next, as shown in FIG. 9(D), a second sheet 53 containing a magnetic material is placed on the side of the coil 20 opposite the first sheet 51. An opening 53A is formed in the center of the second sheet 53. The second sheet 53 is attached to the coil 20 so that the coil 20 is sandwiched between the first sheet 51 and the second sheet 53, thereby obtaining an integrated structure. The structure is heated to produce a completely hardened body of the first sheet 51, paste 52, and second sheet 53. That is, by hardening the paste 52, the hardened paste 52 is integrated with the first sheet 51 and the second sheet 53. Heating is performed, for example, at a temperature of 130°C or higher for 10 hours or more.

[0072] Next, as shown in FIG. 9(E), the inner and outer peripheries of the completely hardened body are cut and removed to produce the coil 10 for contactless power transfer, which includes the coil 20 and the magnetic body 30.

[0073] 4. Example of Effects of the First Embodiment According to the contactless power transfer coil 10 of the first embodiment, the coil 20, excluding the ends 24, 26, is disposed within the magnetic body 30, and in at least one cross section perpendicular to the axis of the conductor wires 22, the magnetic body 30 fills the spaces between adjacent conductor wires 22 in the portion of the coil 20 where the conductor wires 22 are arranged side by side. This configuration makes it difficult for the magnetic field generated from the conductor wires 22 of the coil 20 to leak from the magnetic body 30, thereby suppressing the occurrence of a proximity effect between the adjacent conductor wires 22. This suppresses an increase in the electrical resistance of the coil 20. Furthermore, the contactless power transfer coil 10 is configured such that pores 40 are present in the magnetic body 30 between the adjacent conductor wires 22. This configuration allows the pores 40, which have a relatively high withstand voltage, to be present between the adjacent conductor wires 22 of the coil 20, thereby improving the withstand voltage between the adjacent conductor wires 22. This therefore suppresses an increase in the electrical resistance of the coil 20 while improving the withstand voltage.

[0074] In the contactless power supply coil 10 of the first embodiment, the minimum distance between adjacent conductor wires 22 in the adjacently arranged portions is 0.3 mm or more. With this configuration, a sufficient gap can be provided between the adjacent conductor wires 22, and the withstand voltage between the adjacent conductor wires 22 of the coil 20 can be further improved.

[0075] In the contactless power supply coil 10 of the first embodiment, the average diameter of the pores 40 present in the magnetic body 30 is 100 μm or less. With such a configuration, it is easy to suppress the proximity effect occurring between adjacent conductive wires 22, and it is easy to suppress an increase in the electrical resistance of the coil 20.

[0076] In the contactless power supply coil 10 of the first embodiment, in the adjacently arranged portions, in at least one cross section perpendicular to the axis of the conductor wires 22, a line segment S connecting the centers of gravity G of adjacent conductor wires 22 is contained within the area where the magnetic body 30 is present. With this configuration, it becomes easier to suppress the proximity effect occurring between adjacent conductor wires 22.

[0077] In the contactless power supply coil 10 of the first embodiment, the magnetic body 30 includes a resin and soft magnetic particles. With this configuration, the electrical resistance and withstand voltage of the coil 20 can be easily adjusted by selecting the resin and soft magnetic particles that make up the magnetic body 30.

[0078] In the contactless power supply coil 10 of the first embodiment, the dielectric strength of the magnetic material is 200 V / m or more. With this configuration, short circuits between the conductor wires 22 of the coil 20 can be suppressed.

[0079] In the contactless power supply coil 10 of the first embodiment, the coil 20 has a ring shape, and inside the ring there is a region where the magnetic body 30 is not present. With this configuration, it becomes easier to generate a magnetic force that is directed from the inside of the ring of the coil 20 to the outside.

[0080] The power transmission device 110 of the first embodiment includes the above-described contactless power supply coil 10. With this configuration, it is possible to improve the withstand voltage while suppressing an increase in the electrical resistance of the coil 20 during power transmission.

[0081] The power receiving device 120 of the first embodiment includes the above-described coil 10 for contactless power transfer. With this configuration, it is possible to improve the withstand voltage while suppressing an increase in the electrical resistance of the coil 20 during power reception.

[0082] The power transfer system 100 of the first embodiment includes the power transmitting device 110 and the power receiving device 120. The power transmitting device 110 and the power receiving device 120 include the contactless power supply coil 10. With this configuration, in the power transmitting device 110 and the power receiving device 120, it is possible to improve the withstand voltage while suppressing an increase in the electrical resistance of the coil 20.

[0083] According to the method for manufacturing a contactless power transfer coil of the first embodiment, it is possible to manufacture a contactless power transfer coil 10 in which the coil 20 is embedded in and surrounded by the magnetic body 30. This makes it possible to manufacture a contactless power transfer coil 10 in which the magnetic field generated from the conductor wires 22 of the coil 20 is less likely to leak from the magnetic body 30 and the proximity effect between adjacent conductor wires 22 can be suppressed. Furthermore, since the magnetic material-containing paste 52 containing air bubbles that is filled between adjacent conductor wires 22 in the coil 20 hardens to form the magnetic body 30, it is possible to realize a contactless power transfer coil 10 in which pores 40 exist in the magnetic body 30 between the adjacent conductor wires 22. This results in a contactless power transfer coil 10 in which the withstand voltage between adjacent conductor wires 22 of the coil 20 is improved. Therefore, it is possible to manufacture a contactless power transfer coil 10 in which the withstand voltage can be improved while suppressing an increase in the electrical resistance of the coil 20.

[0084] Second Embodiment A second embodiment of the present invention will be described below with reference to Fig. 11 and Fig. 12. A contactless power supply coil 210 of the second embodiment differs from the first embodiment mainly in that it includes a magnetic member 260, but is otherwise the same as the first embodiment. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0085] As shown in FIGS. 11 and 12, the contactless power supply coil 210 includes a coil 20, a magnetic body 30, a magnetic member 260, and a support member 262.

[0086] The magnetic member 260 has, for example, a flat plate shape. The magnetic member 260 is arranged on one side of the magnetic body 30. In the coil for contactless power supply 210 of the power transmitting device 110, the magnetic member 260 is arranged on the opposite side of the magnetic body 30 from the power receiving device 120. In the coil for contactless power supply 210 of the power receiving device 120, the magnetic member 260 is arranged on the opposite side of the magnetic body 30 from the power transmitting device 110.

[0087] The complex relative permeability of the magnetic member 260 is greater than that of the magnetic body 30. The magnetic member 260 is made of, for example, the same material as the soft magnetic particles contained in the magnetic body 30. Examples of the magnetic member 260 include Ni-Zn ferrite, Mn-Zn ferrite, magnetite, Fe-Si-B alloy, Fe-Si-B-Cr alloy, Fe-Si alloy, Fe-Si-Cr alloy, sendust, permalloy, etc. The real part of the complex relative permeability of the magnetic member 260 at 85 Hz is preferably 500 or more.

[0088] The magnetic body 30 and the magnetic member 260 are supported by each other by a support member 262 disposed between the magnetic body 30 and the magnetic member 260. The support member 262 is made of, for example, resin. The magnetic member 260 and the support member 262 are formed with holes through which, for example, the end portions 24, 26 (see FIGS. 3 and 5) of the coil 20 pass.

[0089] When the thickness of the coil 20 is d, the distance (minimum distance) between the magnetic body 30 and the magnetic member 260 is preferably 0.5d or more and 10d or less. The thickness d of the coil 20 is, for example, 0.5 mm or more and 5 mm or less, and the distance (minimum distance) between the magnetic body 30 and the magnetic member 260 is, for example, 0.25 mm or more and 50 mm or less. Preferably, the thickness d of the coil 20 is 0.8 mm, and the distance (minimum distance) between the magnetic body 30 and the magnetic member 260 is 1 mm or more and 2 mm or less. [[ID=!0]]

[0090] As shown in FIG. 12, in a cross section having a shape symmetric with respect to the central axis C, the width in the direction perpendicular to the central axis C of the coil 20 is defined as L1, and the width in the direction perpendicular to the central axis C of the magnetic member 260 is defined as L3. It is preferable that L1 and L3 satisfy 1 < L3 / L1 < 1.15. Further, it is preferable that the magnetic member 260 protrudes 5 mm or more and 10 mm or less from the outermost edge of the magnetic body 30.

[0091] The contactless power supply coil 210 of the second embodiment includes a magnetic member 260 on one side of the magnetic body 30. The complex relative permeability of the magnetic member 260 is greater than the complex relative permeability of the magnetic body 30. This configuration can improve the inductance of the coil 20, thereby increasing the efficiency of wireless power supply.

[0092] Third Embodiment A third embodiment of the present invention will be described below with reference to Figs. 13 and 14. A contactless power supply coil 310 of the third embodiment differs from the second embodiment mainly in that it includes an electromagnetic shielding member 370, but is otherwise the same as the second embodiment. Note that the same components as those of the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0093] As shown in Figures 13 and 14, the non-contact power supply coil 310 includes a coil 20, a magnetic body 30, a magnetic member 260, a support member 262, an electromagnetic shielding member 370, a second support member 372, a protective member 380, and a frame body 390.

[0094] The electromagnetic shielding member 370 is, for example, in the shape of a flat plate. The magnetic member 260 and the electromagnetic shielding member 370 are arranged in this order on one surface of the magnetic body 30. The electromagnetic shielding member 370 is arranged on the opposite side of the magnetic member 260 to the coil 20 and the magnetic body 30.

[0095] The electromagnetic shielding member 370 has a non-magnetic metal layer and is, for example, an aluminum (Al) plate, an aluminum (Al) alloy plate, a copper (Cu) plate, a copper (Cu) alloy plate, or a resin plate with aluminum foil or copper foil attached thereto.

[0096] The electromagnetic shielding member 370 and the magnetic member 260 are supported by a second support member 372 that is sandwiched between the electromagnetic shielding member 370 and the magnetic member 260. The second support member 372 is made of, for example, resin. The electromagnetic shielding member 370 and the second support member 372 are formed with holes through which, for example, the ends 24, 26 of the coil 20 (see FIGS. 3 and 5) pass.

[0097] The electromagnetic shielding member 370 is preferably disposed at a distance from the magnetic member 260. The electromagnetic shielding member 370 preferably protrudes from the outermost edge of the magnetic member 260 by 5 mm to 10 mm.

[0098] The protective member 380 covers the other surface of the magnetic body 30 (the surface opposite to the magnetic member 260 and the electromagnetic shielding member 370). The protective member 380 is made of, for example, a non-magnetic resin plate, tempered glass, FRP, or the like. The protective member 380 prevents the magnetic body 30 from being scratched.

[0099] The frame body 390 surrounds the side surfaces of the magnetic body 30, the support member 262, the magnetic member 260, and the second support member 372. The protective member 380 and the electromagnetic shielding member 370 are supported by the frame body 390, which is sandwiched between the protective member 380 and the electromagnetic shielding member 370. The frame body 390 is made of, for example, a resin material. The frame body 390 can prevent dust, water, and the like from entering the frame body 390.

[0100] The resistance value of the coil 20 in the contactless power supply coil 310 is preferably 150 mΩ or less. The inductance of the coil 20 in the contactless power supply coil 310 is preferably 40 μH or more.

[0101] A contactless power supply coil 310 of the third embodiment includes a magnetic member 260 and an electromagnetic shielding member 370, in this order, on one side of the magnetic body 30. The complex relative permeability of the magnetic member 260 is greater than the complex relative permeability of the magnetic body 30. With this configuration, electromagnetic noise that may be generated from the coil 20 can be reflected by the electromagnetic shielding member 370, preventing it from leaking to the outside. [Example]

[0102] Next, the above embodiment will be described more specifically with reference to examples and comparative examples. Table 1 shows the configurations of the contactless power supply coils of Examples 1-9 and Comparative Examples 1-6, and the evaluation results.

[0103] [Table 1]

[0104] In Table 1, the "Type of Conductor" column indicates the type of conductor (material, shape) of the coil. For example, "Aluminum Rectangular" indicates that the conductor is made of aluminum (Al) and is configured as a rectangular wire. "Copper Rectangular" indicates that the conductor is made of copper (Cu) and is configured as a rectangular wire. "Copper Litz" indicates that the conductor is made of copper (Cu) and is configured as a Litz wire (a wire made by twisting together multiple copper wires).

[0105] In Table 1, the "Wire Size" column indicates the size (width x thickness) of the coil's conductor wire. The width is the dimension of the conductor wire in a direction perpendicular to the central axis of the coil. The thickness is the dimension of the conductor wire in a direction parallel to the central axis of the coil. In the case of Example 9, it indicates the diameter of the entire conductor wire (litz wire).

[0106] 1. Fabrication of a coil for contactless power transfer For Examples 1-9, the contactless power supply coils were produced using the same method as in "3. Manufacturing method of contactless power supply coil 10" in the first embodiment. The detailed methods for producing the contactless power supply coils for Examples 1-9 and Comparative Examples 1-6 are described below.

[0107] 1-1. Making the coil The coils of flat wire were made by bending prepared flat wire or by punching from a metal plate. The coils of litz wire were made by creating a coil-shaped guide and bending the wire to fit the guide.

[0108] 1-2. Preparation of magnetic material-containing paste (paste) An Fe-Si-B amorphous alloy powder (magnetic powder) with an average particle size of approximately 5-10 μm was added to polydimethylsiloxane (resin material) with a molecular weight of approximately 50,000. The magnetic powder was added so that the final amount added was 57 vol% to obtain a mixture. After the mixture was subjected to blade stirring and roll mixing, a silane coupling agent and a platinum catalyst for the curing reaction were added, and the mixture was subjected to blade stirring again. A crosslinking agent (crosslinking polydimethylsiloxane with a molecular weight of 10,000 or less) was added to the stirred mixture, and the mixture was subjected to blade stirring and vacuum degassing again to obtain a magnetic material-containing paste containing air bubbles.

[0109] 1-3. Preparation of magnetic sheet The paste was thoroughly degassed in advance to eliminate pores. The paste was placed in a green sheet molding machine and molded to a thickness of 400 μm. The resulting sheet molding was heated to obtain a magnetic sheet containing the magnetic material. The magnetic sheet was heated at a temperature of 100°C or less for 1 to 5 hours to obtain a magnetic sheet (first sheet) with adhesive properties. A magnetic sheet (second sheet) containing the magnetic material and a magnetic sheet (third sheet) described below were obtained by the same process.

[0110] 1-4. Combination of coil and magnetic material (with pores): Example 1-9 As shown in FIG. 9(A), a coil 20 was placed on one side of a first sheet 51 containing a magnetic material and integrated with it. Next, as shown in FIG. 9(B), a paste 52 containing air bubbles was injected with a syringe to fill the gaps between adjacent conductive wires 22 in the coil 20. Pores were previously incorporated into the paste by stirring. Vacuum degassing was then performed for 1 minute or less to remove relatively large pores from the paste 52. Next, as shown in FIG. 9(C), excess paste was removed using a scraper to flatten the surface. Next, as shown in FIG. 9(D), a second sheet 53 containing a magnetic material was placed on the opposite side of the coil 20 from the first sheet 51 to obtain an integrated structure. The structure was heated to produce a fully cured body of the first sheet 51, paste 52, and second sheet 53. Heating was performed at a temperature of 130°C or higher for 10 hours or more. Next, as shown in Fig. 9(E), the inner and outer peripheral edges of the completely hardened body were cut and removed to produce a contactless power supply coil including the coil 20 and the magnetic body 30. Note that Fig. 9 shows an example in which the coil is made of rectangular wire, but a litz wire was also produced using the same process.

[0111] 1-5. Combination of coil and magnetic material (without pores): Comparative Examples 5 and 6 FIG. 10 is an explanatory diagram illustrating the manufacturing process of the contactless power transfer coils of Comparative Examples 5 and 6. As shown in FIG. 10, the coil 20 was placed on one side of the first sheet 51 containing a magnetic material and integrated. Next, the magnetic sheet was cut into strips with a width corresponding to the spacing between the conductive wires 22 of the coil 20 to obtain a third sheet 54. The third sheet 54 was attached between the conductive wires 22 of the coil 20. Then, a second sheet 53 containing a magnetic material was placed on the side of the coil 20 opposite the first sheet 51 to obtain an integrated structure. The structure was heated to produce a fully cured body of the first sheet 51, the second sheet 53, and the third sheet 54. The heating was performed at a temperature of 130°C or higher for 10 hours or more.

[0112] 2. Evaluation Method 2-1. Presence or absence of stomata The presence of pores (air bubbles) in the magnetic material between adjacent conductors in the coil was confirmed by cross-sectional SEM observation.

[0113] 2-2. Coil resistance The AC resistance of the fabricated coil was measured at 85 Hz using an LCR meter.

[0114] 2-3.Dielectric strength of insulators For Examples 1-9, the magnetic material-containing paste described above was poured into a Teflon (registered trademark) container to a thickness of 2 mm, vacuum degassed for a short time, and then heat-cured. The cured product was punched out to a size of 10 mm in diameter, and the dielectric strength of the punched sample was measured.

[0115] For Comparative Examples 5 and 6, the magnetic material-containing paste was molded into a sheet having a thickness of 2 mm. The molded sheet was heat-cured and then punched out to a size of 10 mm in diameter. The dielectric strength of the punched sample was measured.

[0116] The dielectric strength was measured using a TOS5302 manufactured by Kikusui Electronics Co., Ltd. The measurement was carried out in oil, and the point at which the voltage dropped due to dielectric breakdown was taken as the dielectric strength.

[0117] 3. Evaluation Results 3-1. Presence or absence of stomata In Examples 1-9, pores (air bubbles) were present in the magnetic material between adjacent conductor wires in the coil. The average diameter of the pores was about 50 μm. The average diameter of the pores was measured using the same method as in the first embodiment.

[0118] 3-2. Coil resistance The coils of Example 1-4 were made of aluminum rectangular wire (flat wire made of aluminum (Al)). The inter-wire distances of the coils of Example 1-4 were 0.2 mm, 0.3 mm, 1.4 mm, and 2.5 mm. The resistances of the coils of Example 1-4 were 99 mΩ, 95 mΩ, 82 mΩ, and 63 mΩ. These results show that in contactless power transfer coils made of aluminum rectangular wire, the resistance of the coil decreases as the inter-wire distance increases.

[0119] The coils of Examples 5 and 6 were made of copper rectangular wire (rectangular wire made of copper (Cu)). The inter-conductor distance of the coils of Examples 5 and 6 was 1.4 mm and 2.5 mm, respectively. The resistance of the coils of Examples 5 and 6 was 50 mΩ and 40 mΩ. These results show that in contactless power transfer coils made of copper rectangular wire, the resistance of the coil decreases as the inter-conductor distance increases. Furthermore, because copper (Cu) has a lower resistivity than aluminum (Al), it is thought that the coil resistance of Examples 5 and 6 was lower than that of Examples 1-4.

[0120] The contactless power transfer coils of Examples 3-6 include a magnetic material. The contactless power transfer coils of Comparative Examples 1-4 do not include a magnetic material. The coil configurations of Examples 3-6 are the same as the coil configurations of Comparative Examples 1-4. The coil resistances of Examples 3-6 were 82 mΩ, 63 mΩ, 50 mΩ, and 40 mΩ. The coil resistances of Comparative Examples 1-4 were 145 mΩ, 120 mΩ, 91 mΩ, and 75 mΩ. These results show that the resistance of the contactless power transfer coils is significantly reduced by including a magnetic material.

[0121] The coils of Examples 4 and 7 were made of aluminum rectangular wire (rectangular wire made of aluminum (Al)). The thickness of the coil of Example 4 was 0.8 mm. The thickness of the coil of Example 7 was 0.6 mm. The coil resistances of Examples 4 and 7 were 63 mΩ and 64 mΩ. From these results, it can be considered that when the coil thickness is reduced, the cross-sectional area of ​​the conductor becomes smaller and current does not flow easily, but the skin effect becomes smaller and an equivalent coil resistance can be obtained.

[0122] The coils of Examples 7 and 8 were aluminum rectangular wires (rectangular wires made of aluminum (Al)). The width of the coil of Example 7 was 8 mm. The width of the coil of Example 8 was 16 mm. The coil resistances of Examples 4 and 7 were 64 mΩ and 52 mΩ. These results show that when the coil width is increased, the cross-sectional area of ​​the conductor wire increases and the coil resistance decreases.

[0123] The coil of Example 9 is a copper Litz wire (a Litz wire made of copper (Cu)). The coil resistance of Example 9 was 35 mΩ. This result shows that even if the coil is made of copper Litz wire, a sufficiently low coil resistance can be obtained.

[0124] 3-3.Dielectric strength of insulators The coil of Example 5 and the coil of Comparative Example 5 are made of copper rectangular wire (rectangular wire made of copper (Cu)). In Example 5, pores are present in the magnetic material between adjacent conductor wires in the coil. In Comparative Example 5, pores are not present in the magnetic material between adjacent conductor wires in the coil. The configuration of the coil of Example 5 is the same as the configuration of the coil of Comparative Example 5. The dielectric strength of the insulator of Example 5 was 1.2 kV / mm. The dielectric strength of the insulator of Comparative Example 5 was 0.7 kV / mm. These results show that in a contactless power transfer coil whose coil is made of copper rectangular wire, the presence of pores in the magnetic material between adjacent conductor wires in the coil increases the dielectric strength of the insulator.

[0125] The coil of Example 3 and the coil of Comparative Example 6 are made of aluminum flat wire (flat wire made of aluminum (Al)). In Example 3, pores are present in the magnetic material between adjacent conductor wires in the coil. In Comparative Example 6, pores are not present in the magnetic material between adjacent conductor wires in the coil. The configuration of the coil of Example 3 is the same as the configuration of the coil of Comparative Example 6. The dielectric strength of the insulator of Example 3 was 1.2 kV / mm. The dielectric strength of the insulator of Comparative Example 6 was 0.7 kV / mm. These results show that in a contactless power transfer coil whose coil is made of aluminum flat wire, the presence of pores in the magnetic material between adjacent conductor wires in the coil increases the dielectric strength of the insulator.

[0126] 4. Effects of the Example According to the above examples, the contactless power transfer coil has a magnetic body surrounding the coil, which significantly reduces the resistance of the coil. Also, the contactless power transfer coil has pores in the magnetic body between adjacent conductors, which increases the dielectric strength of the insulator.

[0127] <Other embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of features of the above-described or following embodiments is possible within a range that does not contradict. Furthermore, any feature of the above-described or following embodiments may be omitted unless explicitly stated as essential. Furthermore, the above-described embodiment may be modified as follows.

[0128] In the first to third embodiments, the power transmission system 100 is configured as a system for supplying power wirelessly (contactlessly) to an electric vehicle, but is not limited thereto. For example, the power transmission system 100 may be used in a transformer, a DC-DC converter, an antenna, etc.

[0129] In the first to third embodiments, the coil 20 is wound to form a rectangle, but it may be wound to form a circle. Also, the coil 20 is wound to form a square with rounded corners, but it may be wound to form a square with sharp corners.

[0130] In the first to third embodiments, a rectangular wire is used as the coil 20, but a litz wire (a wire made by twisting together a plurality of conducting wires) may also be used. The diameter of the litz wire is preferably 20 μm or more and 500 μm or less.

[0131] In the first to third embodiments, the coils 20 may be arranged in a plurality of stages spaced apart from one another in the axial direction.

[0132] In the first to third embodiments, there is an area inside the ring of the coil 20 where the magnetic body 30 does not exist, but as shown in Figure 15, the inside of the ring of the coil 20 may also be filled with the magnetic body 30.

[0133] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0134] 10: Contactless power supply coil 20: Coil 22: Conductor 24,26: End 30: Magnetic material 32,34: Hole 40: Pores (air bubbles) 51: 1st sheet 52: Magnetic material-containing paste 53: Second sheet 100: Power transmission systems 110: Power transmission equipment 112: Conversion section 114: Power supply 120: Power receiving device 122: Conversion section 124: Battery 126: Motor 210: Contactless power supply coil 260: Magnetic materials 262: Support member 310: Contactless power supply coil 370: Electromagnetic shielding materials 372: Second support member 380: Protective materials 390: Frame

Claims

1. a planar coil formed by winding a conductor in a planar shape; A contactless power supply coil including a magnetic body, The ends of the coil are electrode connection portions, the coil, excluding the end portion, is embedded in the magnetic body, and is surrounded by the magnetic body; In at least one cross section perpendicular to the axis of the conductor, the magnetic material fills the spaces between adjacent conductors in a portion of the coil where the conductors are arranged side by side, Pores are present in the magnetic body between adjacent conductive wires. Coil for contactless power supply.

2. In the adjacently arranged portion, the minimum distance between adjacent conductive wires is 0.3 mm or more. The contactless power supply coil according to claim 1 .

3. The average diameter of the pores present in the magnetic body is 100 μm or less. The contactless power supply coil according to claim 1 or 2.

4. In the adjacently arranged portions, in at least one cross section perpendicular to the axis of the conductor, a line segment connecting the centers of gravity of adjacent conductors is contained within an area where the magnetic material exists. The contactless power supply coil according to claim 1 or 2.

5. The magnetic material includes a resin and soft magnetic particles. The contactless power supply coil according to claim 1 or 2.

6. The dielectric strength of the magnetic material is 200 V / m or more. The contactless power supply coil according to claim 1 or 2.

7. the coil is in the form of a ring; There is a region within the ring where the magnetic material is not present. The contactless power supply coil according to claim 1 or 2.

8. a magnetic member provided on one surface of the magnetic body; The complex relative permeability of the magnetic member is greater than the complex relative permeability of the magnetic body. The contactless power supply coil according to claim 1 or 2.

9. a magnetic member and an electromagnetic shielding member are provided in this order on one surface of the magnetic body; The complex relative permeability of the magnetic member is greater than the complex relative permeability of the magnetic body. The contactless power supply coil according to claim 1 or 2.

10. A power transmission device comprising the contactless power supply coil according to claim 1 or 2.

11. A power receiving device comprising the contactless power supply coil according to claim 1 or 2.

12. The power transmission device includes a power receiving device. A power transfer system, wherein at least one of the power transmitting device and the power receiving device comprises the coil for contactless power transfer according to claim 1 or 2.

13. A method for manufacturing a coil for contactless power supply including a planar coil formed by winding a conductive wire in a planar shape and a magnetic body, The coil is disposed on one surface of a first sheet containing a magnetic material; Filling the spaces between the adjacent conductor wires in the coil with a paste containing a magnetic material and containing air bubbles; Furthermore, a second sheet containing a magnetic material is placed on the opposite side of the coil from the first sheet, Thereafter, the magnetic material-containing paste is hardened, thereby integrating the hardened magnetic material-containing paste with the first sheet and the second sheet to form the magnetic body. Manufacturing method for contactless power supply coils.

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