Coil components, power transmission equipment, power receiving equipment, and power transmission systems

Abstract

To provide a coil component which can discharge heat of a coil efficiently.SOLUTION: A coil component 10A according to one embodiment includes: a spiral shaped coil 11; a case 20 serving as a storage member for storing the coil 11; and spacer members 40 each serving as a heat conductive member which transmits heat of the coil 11 to an inner surface of the case 20. The spacer members 40 are located in an inner range of an outer peripheral edge 11ep of the coil 11 in a radial direction of the coil 11.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a coil component, a power transmitting device, a power receiving device, and a power transmission system.

Background Art

[0002] Wireless power transmission systems that transmit power in a non-contact manner are becoming widespread.

[0003] When large power is transmitted in a non-contact manner, a high-frequency large current flows through a resonant circuit including a coil. At this time, the heat generation amount of the coil increases. The heat generation amount of the coil increases due to, for example, the skin effect.

[0004] When a litz wire is used as the coil, the skin effect is suppressed. Therefore, heat generation of the coil can be suppressed. However, since a litz wire is formed by twisting a large number of enameled wires, the manufacturing cost is high and the manufacturing process is labor-intensive. In a high-power system, the coil can be large, so the manufacturing cost and the labor required for manufacturing can further increase.

[0005] On the other hand, a technique that employs a planar coil which is spiral and plate-shaped and has a rectangular conductor cross-section is also known (see Patent Document 1). According to such a planar coil, the manufacturing efficiency can be improved regardless of the size of the coil. Therefore, such a planar coil is suitable for high-power systems where the coil size can be large.

[0006] In a wireless power transmission system for electric vehicles, a power transmitting device is installed on a road surface such as a parking lot, and a power receiving device is installed in the electric vehicle. For example, when the above planar coil is used in an electric vehicle application, the height dimension can be particularly suppressed in both the power transmitting device and the power receiving device. Therefore, the above planar coil functions beneficially in, for example, the vehicle field where strict space constraints are imposed.

[0007] Furthermore, when coils are incorporated into the power transmission and receiving devices described above, the coils are usually housed in a case. In this case, the case may hinder the heat dissipation of the coil. Therefore, various techniques for heat dissipation when coils are housed in a case have been proposed (for example, Patent Documents 2 and 3). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2021-27112 [Patent Document 2] Japanese Patent Publication No. 2019-30089 [Patent Document 3] International Publication No. 2013 / 183105 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] When introducing a refrigerant, such as cooling air, from the outside to the inside of a case, holes are needed for the refrigerant to pass through. Such holes may reduce the waterproof and dustproof performance. Alternatively, a heat-conducting component can be housed in the case along with the coil, and the heat from the coil can be dissipated to the outside through the heat-conducting component and the case. However, in this configuration, the installation of the heat-conducting component may lead to an increase in weight and the size of the case. Furthermore, the heat-conducting component may include parts that do not contribute significantly to heat dissipation. In addition, the heat-conducting component may impose constraints on the size and installation of other components.

[0010] This disclosure has been made in consideration of the above circumstances, and the problem to be addressed is to provide a coil component, a power transmission device, a power receiving device, and a power transmission system that can efficiently dissipate heat from a coil. [Means for solving the problem]

[0011] A coil component according to one embodiment comprises a spiral-shaped coil, a housing member for housing the coil, and a thermally conductive member for transferring heat from the coil to the inner surface of the housing member, wherein the thermally conductive member is located in the radial direction of the coil, within the range inward of the outer peripheral edge of the coil.

[0012] The heat-conducting member may also be a spacer member that maintains a state in which the coil and the inner surface of the housing member are separated.

[0013] The heat-conducting member may overlap with the coil in the axial direction of the coil.

[0014] Multiple thermal conductive members may be provided, and these multiple thermal conductive members may be scattered within the area in the radial direction that is inward from the outer edge of the coil.

[0015] The coil includes a plurality of turns arranged radially outward from the central axis of the spiral shape, and at least a portion of the plurality of heat-conducting members may be arranged in a range from the innermost turn of the plurality of turns to the largest integer turn that is less than or equal to the number of turns of the coil divided by 2, counting from the innermost turn.

[0016] The heat-conducting member does not necessarily have to be provided in the radially inward range of the innermost turn portion.

[0017] A coil component according to one embodiment further comprises a plate-shaped support member extending along the radial direction, wherein the support member is thermally conductive and may be provided between the thermally conductive member and the coil.

[0018] The support member includes a central portion that coincides with the central axis of the coil in the axial direction of the coil, and an outer frame portion that surrounds the central portion and connects to the central portion, wherein the thermal conductivity of the central portion may be greater than that of the outer frame portion.

[0019] A coil component according to one embodiment may further include a sheet-shaped magnetic member extending along the radial direction, and the magnetic member may be provided between the support member and the coil.

[0020] The support member may be located inward of the outer peripheral edge of the magnetic member in the radial direction.

[0021] The support member may have a rectangular shape, and may be located inward of the outer peripheral edge of the coil in the radial direction except at the four corners.

[0022] The thermal conductivity of the support member may be 1 W / m·k or higher. The thermal conductivity of the thermally conductive member may be 1 W / m·k or higher.

[0023] A power transmission device according to one embodiment includes the coil component described above. A power reception device according to one embodiment includes the coil component described above. A power transmission system according to one embodiment includes a power transmission device and a power reception device, and at least one of the power transmission device and the power reception device includes the coil component described above. [Advantageous Effects of the Invention]

[0024] According to the present disclosure, heat of the coil can be efficiently dissipated. [Brief Description of the Drawings]

[0025] [Figure 1] It is a diagram schematically illustrating a wireless power transmission system to which the coil component according to the embodiment can be applied. [Figure 2] It is a perspective view of the coil component according to the first embodiment. [Figure 3] It is an exploded perspective view of the coil component according to the first embodiment. [Figure 4] It is a cross-sectional view of the coil component taken along line IV-IV in FIG. 2. [Figure 5] It is a plan view of the coil component according to the first embodiment. [Figure 6] This figure shows a table illustrating the relationship between the size difference between the support member and the magnetic shielding member in the coil component according to the first embodiment, and the Q value. [Figure 7] This figure shows a graph illustrating the relationship between the size difference between the support member and the magnetic shielding member in the coil component according to the first embodiment, and the Q value. [Figure 8] This is a plan view of a coil component according to the second embodiment. [Figure 9] This is a cross-sectional view of a coil component according to the third embodiment. [Figure 10] This is a cross-sectional view of a coil component according to the fourth embodiment. [Figure 11] This is a cross-sectional view of a coil component according to the fifth embodiment. [Figure 12] This is a cross-sectional view of a coil component according to the sixth embodiment. [Figure 13] This is a diagram showing a coil component according to the seventh embodiment. [Figure 14] This figure shows a coil component according to the eighth embodiment. [Modes for carrying out the invention]

[0026] The embodiments will be described below with reference to the drawings.

[0027] In this specification, terms such as "sheet," "film," and "plate" are not distinguished from each other solely based on differences in name. Therefore, for example, "sheet" is a concept that includes components that could also be called films or plates.

[0028] Furthermore, in this specification, "sheet surface (board surface, film surface)" refers to the surface that coincides with the planar direction (surface direction) of the sheet-like member in question when viewed as a whole and in a broad sense.

[0029] <Wireless Power Transmission System> Figure 1 schematically shows a wireless power transmission system S to which coil components according to the embodiment described later may be applied. First, the wireless power transmission system S (hereinafter abbreviated as power transmission system S) will be explained with reference to Figure 1.

[0030] The power transmission system S comprises a power transmission device 1 and a power receiving device 2. The power transmission device 1 includes a coil component 10 and a high-frequency current supply unit 1A. The coil component 10 in the power transmission device 1 functions as a power transmission coil. The high-frequency current supply unit 1A supplies high-frequency current to the coil component 10 as a power transmission coil.

[0031] The power receiving device 2 includes a coil component 10 and a conversion unit 2A. The coil component 10 in the power receiving device 2 functions as a power receiving coil. The conversion unit 2A shapes the high-frequency current generated in the coil component 10. The conversion unit 2A has a rectifier circuit and the like that converts the high-frequency current into a DC current.

[0032] When transmitting power wirelessly (contactlessly) from the power transmission device 1 to the power receiving device 2, the power transmission device 1 supplies a high-frequency current of a predetermined frequency to the coil component 10, which acts as a power transmission coil, from the high-frequency current supply unit 1A. At this time, a magnetic field is generated in the coil component 10 due to electromagnetic induction. Due to the influence of this magnetic field, a high-frequency current is generated in the coil component 10, which acts as a power receiving coil, in the power receiving device 2. The conversion unit 2A converts this high-frequency current into a DC current and supplies the converted DC current to, for example, a battery (not shown).

[0033] The power transmission system S shown in Figure 1 employs a magnetic resonance method as the power transmission method. However, the power transmission system S may also be configured as an electromagnetic induction power transmission system. Furthermore, the power transmission system S is configured as a system that wirelessly transmits power to an electric vehicle. In this case, the power transmission device 1 is installed on a road, parking lot, etc. The power receiving device 2 is installed in the electric vehicle.

[0034] However, the applications of the power transmission system S are not limited to power transmission to electric vehicles. For example, the power transmission system S may be used for power transmission to flying objects such as drones and robots. Furthermore, the power transmission system S may be used for power transmission to submersibles and exploration robots in the ocean. It should also be noted that the applications of the coil components according to this embodiment are not limited to wireless power transmission systems. For example, the coil components according to this embodiment may be used in transformers, DC-DC converters, antennas, and the like.

[0035] Each power transmission system S includes, as a coil component 10, one of the coil components according to each embodiment described later. Note that the same coil component from the same embodiment may be used in both the power transmission device 1 and the power receiving device 2. Alternatively, different coil components from different embodiments may be used in both the power transmission device 1 and the power receiving device 2. Furthermore, one of the power transmission device 1 and the power receiving device 2 may use a coil component from one embodiment, while the other uses a coil component of another type. The coil components according to each embodiment will be described below.

[0036] <First Embodiment> Figure 2 is a perspective view of the coil component 10A according to the first embodiment. Figure 3 is an exploded perspective view of the coil component 10A. Figure 4 is a cross-sectional view of the coil component 10A along the line IV-IV in Figure 2.

[0037] As shown in Figures 2 to 4, the coil component 10A comprises a coil 11, a case 20, a spacer member 40, a support member 42, a magnetic shielding member 44, an insulating member 46, a first connection terminal 51, and a second connection terminal 52.

[0038] Case 20 has a bottom wall portion 22, a side wall portion 23 rising from the bottom wall portion 22, and a top wall portion 24 provided at the tip of the side wall portion 23. In Figure 2, for the sake of explanation, the top wall portion 24 is shown in a separated state. The first connection terminal 51 and the second connection terminal 52 are simply indicated by dashed lines.

[0039] The case 20 houses the coil 11, support member 42, magnetic shielding member 44, and insulating member 46. As will be described later, the spacer member 40 is integrated with the bottom wall 22, but is located in the internal space of the case 20 surrounded by the bottom wall 22, side wall 23, and top wall 24. The spacer member 40, support member 42, magnetic shielding member 44, and insulating member 46 are located on the bottom wall 22 in this order. The spacer member 40, magnetic shielding member 44, and insulating member 46 are each in sheet form and overlap each other. Furthermore, the spacer member 40, support member 42, magnetic shielding member 44, insulating member 46, and coil 11 are surrounded by the side wall 23 and covered from above by the top wall 24 in Figure 3.

[0040] The spacer member 40 is interposed between the bottom wall portion 22 and the support member 42, the magnetic shield member 44, and the insulating member 46, thereby supporting the support member 42, the magnetic shield member 44, and the insulating member 46. The coil 11 is a planar coil, as will be described later, and is integrated with the sheet-like insulating member 46. As a result, the coil 11 is held away from the bottom wall portion 22.

[0041] The coil component 10A comprises a plurality of spacer members 40, which in this embodiment are columnar or needle-shaped. One end of the spacer member 40 is in contact with the support member 42, and the other end of the spacer member 40 is in contact with the bottom wall portion 22, i.e., the inner surface of the case 20. More specifically, the other end of the spacer member 40 is connected to the bottom wall portion 22. The spacer member 40 is a member corresponding to a thermally conductive member, and the spacer member 40 has thermal conductivity, receiving the heat generated in the coil 11 from the support member 42 and transferring it to the bottom wall portion 22, i.e., the inner surface of the case 20. This allows the coil component 10A to dissipate the heat from the coil 11 to the outside. Thermal conductivity is the property of transferring heat from a high-temperature part of an object to a low-temperature part of the object, and means having a thermal conductivity that is at least greater than the thermal conductivity (W / m·k) of gases such as air or resins. The following describes in detail each part that constitutes the coil component 10A.

[0042] (coil) Figure 5 is a plan view of the coil component 10A. In Figure 5, the case 20 is not shown. The coil 11 is spiral-shaped and made of a conductive material. In this embodiment, the coil 11 is made of copper, but the coil 11 can be made of any conductive material, such as aluminum. In Figure 5, dots are marked on the area of ​​the coil 11 for ease of explanation.

[0043] The coil 11 is plate-shaped; that is, the coil 11 is a planar coil. More specifically, the coil 11 is a planar coil made of non-Litz wire. As shown in Figure 3, the cross-sectional shape of the conductor in the direction perpendicular to the circumferential direction of the spiral shape of the coil 11 is rectangular.

[0044] In Figures 2 to 5, the symbol C indicates the central axis of the coil 11, passing through the center of the spiral shape of the coil 11. Hereinafter, when referring to the axial direction of the coil 11, it means the direction extending along the central axis C or the direction parallel to the central axis C. The direction perpendicular to the central axis C is called the radial direction.

[0045] The coil 11 includes a conductor 11E having a spiral shape. The conductor 11E includes a plurality of turned portions 12n. The plurality of turned portions 12n are arranged radially outward from the central axis C of the spiral shape. The plurality of turned portions 12n are arranged radially so as to move radially outward from the central axis C and are connected in sequence, thereby forming a spiral shape. In other words, a spiral shape means the shape of a planar curve wound in a helical manner. More specifically, a spiral shape is a shape that circles around a certain position, with the radial positions moving away from the central position in sequence. In the illustrated embodiment, the spiral shape is located on a virtual plane perpendicular to the central axis.

[0046] The turn section 12n has a shape in which the linear conductor portion does not form a ring but rotates 360 degrees around the central axis C. In the case of a so-called planar coil, both ends of the turn section 12n are offset in the radial direction. In a group of turn sections 12n, the radially inward end of one turn section 12n is connected to the radially outward end of another turn section 12n, and the other turn sections 12n extend away from the central axis C.

[0047] In turn section 12n, "n" represents a variable that takes a number from 1 corresponding to the number of turns in coil 11. Below, the turn section 12n closest to the central axis C may be referred to as turn section 121. Additionally, the turn section connected to the radially outer end of turn section 121 may be referred to as turn section 122, and the turn section connected to the radially outer end of turn section 122 may be referred to as turn section 123. In the example in Figure 5, the number of turns is 9, and the multiple turn sections 12n are composed of 9 turn sections 121 to 129. Turn section 129 corresponds to the turn section located on the outermost periphery.

[0048] Furthermore, "inside the radial direction of a component" means a position closer to the central axis C than the component itself. Conversely, "outside the radial direction of a component" means a position further outward in the radial direction than the component itself. For example, "inside the radial direction of coil 11" means a position closer to the central axis C than the innermost turn portion 121. "Outside the radial direction of coil 11" means a position further outward in the radial direction than the outermost turn portion 129.

[0049] In the illustrated example, the first turn 12n from the radially inner side of the coil 11 is turn 121, and the second turn 12n from the radially inner side of the coil 11 is 122. The first turn 12n from the radially outer side of the coil 11 is turn 129, and the second turn 12n from the radially outer side of the coil 11 is 128. When describing the positional relationship between two members, they are sometimes referred to as the radially inner member and the radially outer member. In this case, the member closer to the central axis C of the two members corresponds to the radially inner member. Also, the member located radially further away from the radially inner member corresponds to the radially outer member. In Figure 5, the reference line St, shown by the dashed line, indicates the boundary where the radially outer end of the radially inner turn 12n and the radially inner end of the radially outer turn 12n connect. The start and end of the turn 12n are located on the reference line St in the illustrated example.

[0050] In the following explanation, when describing matters common to each of the multiple turn sections 12n, they will generally be referred to as "turn section 12n".

[0051] In this embodiment, the turn portion 12n circulates in a rectangular shape. As a result, the shape of the coil 11 in plan view is also rectangular. Although the turn portion 12n shown in Figure 5 circulates in a rectangular shape, the shape of the turn portion 12n is not particularly limited. For example, part or all of the turn portion 12n may have a circular shape. In this specification and disclosure, the spiral shape refers to the shape of a planar curve wound in a spiral shape as described above. The planar curve referred to here also includes planar patterns that are bent and connected in a broken line shape as shown in the figure.

[0052] Furthermore, the number of pairs of radially adjacent turn portions 12n in the conductor 11E is 8, since the number of turns is 9. In this embodiment, the width of the gap between a certain pair of adjacent turn portions 12n is constant, but it may differ in size from the constant gap between other pairs of adjacent turn portions 12n.

[0053] Specifically, between the first to fourth turn sections 121-124 from the radially inward side of the coil 11, the gap between all adjacent pairs of turn sections 12n is constant. Similarly, between the fifth to ninth turn sections 125-129 from the radially inward side of the coil 11, the gap between all adjacent pairs of turn sections 12n is constant. However, the gap between adjacent pairs of turn sections 12n that is constant in the five turn sections 125-129 from the radially inward side is smaller than the gap between adjacent pairs of turn sections 12n that is constant in the four turn sections 121-124 from the first to fourth turn sections from the radially inward side.

[0054] In other words, in this embodiment, the gap between adjacent turn portions 12n located at a position greater than the value obtained by dividing the number of turns n of the coil 11 by 2 is smaller than the gap between adjacent turn portions 12n located at a position less than the value obtained by dividing the number of turns n by 2. The size of the gap may be determined by comparing the value obtained by dividing the total area of ​​the gaps between all pairs of adjacent turn portions 12n located at a position greater than the value obtained by dividing the total area of ​​the gaps between all pairs of adjacent turn portions 12n located at a position less than the value obtained by dividing the total area of ​​the gaps between all connected turn portions located at a position less than the value obtained by dividing the gaps between all connected turn portions located at a position less than the value obtained by dividing the gaps between all connected turn portions located at a position less than the value obtained by dividing the gaps between all connected turn portions located at a position less than the value obtained by dividing the gaps between all connected turn portions located at a position less than the value obtained by dividing the gaps between all connected turn portions located at a position less than the value obtained by dividing the gaps between all connected turn portions located at a position less connected

[0055] The coil 11 described above is formed, for example, by punching a spiral shape out of a copper plate. Alternatively, the coil 11 can also be formed by etching a spiral shape out of copper foil. In this case, the coil 11 can be formed with a complex spiral pattern. However, etching is time-consuming in ensuring the thickness of the coil 11 that is capable of transmitting high power. Therefore, punching is preferable from the viewpoint of manufacturing efficiency.

[0056] Furthermore, the thickness of the conductor 11E in the coil 11, in other words, the thickness of the turn portion 12n, may be, for example, 0.2 mm or more and 1.0 mm or less. Also, the radius of the coil 11 (the distance from the central axis C to the part furthest in the radial direction) may be 200 mm or more. When transmitting power to an electric vehicle using a magnetic resonance method, the radius of the coil 11 (the distance from the central axis C to the part furthest in the radial direction) is usually 200 mm or more and 350 mm or less. In this embodiment, the coil 11 is rectangular in shape, but in this case, the size of the coil 11 is within the range of a radius of 350 mm from the central axis C, the maximum dimension in the longitudinal direction may be 500 mm or more and 700 mm or less, and the maximum dimension in the short direction perpendicular to the longitudinal direction may be 400 mm or more and 650 mm or less. Furthermore, when transmitting power to an electric vehicle using a magnetic resonance method, it is desirable to be able to transmit power of 1 kW or more, preferably 5 kW or more, in the high-frequency current range of 10 kHz to 200 kHz, particularly 79 kHz to 90 kHz. In this case, the thickness of the copper coil 11 is preferably 0.4 mm or more. However, if the thickness of the coil 11 is too large, the weight will increase, which is undesirable, for example, for vehicle installation. Therefore, the thickness of the coil 11 may be, for example, 2.0 mm or less, 1.5 mm or less, or 1.0 mm or less.

[0057] The wire width of the conductor 11E in the coil 11 is not particularly limited. However, considering the ability to transmit power of 1 kW or more, preferably 5 kW or more, in the high-frequency current range of 79 kHz to 90 kHz, the wire width of the turn portion 12n may be 2 mm to 20 mm, 2 mm to 16 mm, 2 mm to 12 mm, or 2 mm to 8 mm. Note that the wire width refers to the distance between the inner and outer surfaces of the conductor 11E in a cross section perpendicular to the direction in which the conductor 11E circulates.

[0058] In this embodiment, the central axis C of the spiral shape described above is determined as follows. First, starting from the radially inward end of the innermost turn portion 121, linear virtual turn portions similar in shape to the innermost turn portion 121 are sequentially drawn radially inward to form a spiral shape. Drawing is continued until a virtual turn portion that fits within a diameter of 1 cm can be drawn. Then, a line passing radially inward through the virtual turn portion that fits within a diameter of 1 cm, in a direction perpendicular to the circumferential and radial directions of the spiral shape, is determined as the central axis C.

[0059] (case) As described above, case 20 has a bottom wall portion 22, a side wall portion 23, and a top wall portion 24. The bottom wall portion 22 is plate-shaped. The side wall portion 23 rises from the periphery of the bottom wall portion 22 and is located on the outer circumference of the coil 11. The side wall portion 23 surrounds the coil 11, the spacer member 40, the support member 42, the magnetic shield member 44, and the insulating member 46. The top wall portion 24 is connected to the tip of the side wall portion 23 and closes the side wall portion 23.

[0060] Case 20 is rectangular in plan view, and the bottom wall 22 and top wall 24 are also rectangular in plan view. The side wall 23 is rectangular in shape in plan view. However, the shape of case 20 in plan view is not particularly limited and may be other shapes such as circular. The coil component 10A may be incorporated into, for example, a power transmission device installed on the road surface. In a power transmission device installed on the road surface, it is assumed that vehicles may drive over the power transmission device. In this case, the top wall 24 covers and protects the coil 11 from above.

[0061] In this embodiment, as an example, the side wall portion 23 and the top wall portion 24 are integrally formed and made from the same material. The bottom wall portion 22 is formed separately from the side wall portion 23 and the top wall portion 24. The bottom wall portion 22 is made of a metallic material and may be conductive. Specifically, the bottom wall portion 22 is made of aluminum.

[0062] As described above, the coil component 10A is expected to be incorporated into a power transmission device installed on the road surface. In this case, it is preferable that the side walls 23 and top wall 24 have high rigidity and strength. For this reason, the material of the side walls 23 and top wall 24 may be fiber-reinforced plastic or the like. The material of the side walls 23 and top wall 24 is not particularly limited. However, in the coil component 10A, it is assumed that magnetism generated by the coil 11 or magnetism from other coils will be transmitted and received through the top wall 24. Therefore, a material that does not block magnetism is selected as the material forming the top wall 24. It is preferable that the top wall 24 has high rigidity and strength, and is non-conductive (insulating) and non-magnetic. Considering these points, fiber-reinforced plastic is a good material for the top wall 24. Insulation means that the volume resistivity is 10 10 This means it is greater than or equal to Ω·m. Non-magnetic means it does not exhibit magnetism.

[0063] The side wall portion 23 and the top wall portion 24 may be formed as a single piece, for example, by injection molding. Alternatively, the side wall portion 23 and the top wall portion 24 may be formed separately and then joined together by welding or other means.

[0064] The bottom wall portion 22 may be formed from a different material than the top wall portion 24 and the side wall portions 23. The material of the bottom wall portion 22 may be aluminum alloy, stainless steel, synthetic resin, etc. When the bottom wall portion 22 is formed from aluminum, aluminum alloy, stainless steel, etc., it also functions as a magnetic shield to prevent magnetic leakage to the outside. When the bottom wall portion 22 is formed from synthetic resin such as fiber-reinforced plastic, it may be advantageous in terms of productivity and weight reduction. However, the material of the bottom wall portion 22 is not particularly limited.

[0065] The manner in which the bottom wall portion 22 is attached to the side wall portion 23 is not particularly limited. The bottom wall portion 22 may be detachably attached to the side wall portion 23 by fastening means such as screws or bolts. The bottom wall portion 22 may be attached to the side wall portion 23 by welding or by adhesive.

[0066] (Spacer member) As shown in Figures 3 to 5, multiple spacer members 40 are arranged so as to be scattered on the bottom wall portion 22. More specifically, when viewed in the axial direction of the coil 11, all of the multiple spacer members 40 are located within the range inside the outer peripheral edge 11ep of the coil 11. In other words, all of the multiple spacer members 40 are located within the range inside the outer peripheral edge 11ep of the coil 11 in the radial direction. The outer peripheral edge 11ep of the coil 11 is the portion where the points located furthest outward in the radial direction of the coil 11 are connected in the circumferential direction. Figure 5 shows a dashed line CL extending along the outer peripheral edge 11ep. That is, in this embodiment, the outer peripheral edge 11ep is formed by a part of the outer peripheral edge of the outermost turn portion 129 and the outer peripheral edge of the outer lead portion 13e connected to the radially outward end of the turn portion 129. The outer lead portion 13e is located radially outward from the starting end portion of the turn portion 129. Note that some of the multiple spacer members 40 may be located radially outside the outer peripheral edge 11ep of the coil 11. However, in this case, it is desirable that the spacer member 40 located outside the outer peripheral edge 11ep be nonmagnetic.

[0067] The condition "when viewed in the axial direction" when specifying the configuration is synonymous with "when projected in the axial direction." Therefore, the configuration "when viewed in the axial direction" is not limited to the configuration that can be observed by human vision when the actual coil components are viewed from the axial direction. For example, "when viewed in the axial direction of the coil 11, at least some of the multiple spacer members 40 are located within the range inside the outer edge 11ep of the coil 11" means that in the projection in the axial direction, at least some of the multiple spacer members 40 are located within the range inside the outer edge 11ep of the coil 11, and this also applies to cases where the spacer members 40 located within the range inside the outer edge 11ep are obscured by other components and cannot be confirmed by visual inspection.

[0068] In this embodiment, spacer members 40 are arranged at intervals along the longitudinal direction of the bottom wall portion 22 of the rectangular case 20, and along the short direction of the bottom wall portion 22 perpendicular to the longitudinal direction. Each spacer member 40 is in contact with the bottom wall portion 22 and the support member 42. In the illustrated example, when viewed in the axial direction of the coil 11, more than 50% of the multiple spacer members 40 are scattered within the area inside the outer peripheral edge 11ep. As described above, the spacer members 40 have thermal conductivity and can receive heat generated in the coil 11 from the support member 42 and transfer it to the bottom wall portion 22, i.e., to the inner surface of the case 20. The coil 11 generates heat as a whole when a high-frequency current is applied. Therefore, by arranging most of the spacer members 40 so that they are located within the area inside the outer peripheral edge 11ep of the coil 11 when viewed in the axial direction, the heat from the coil 11 is efficiently dissipated to the outside.

[0069] Furthermore, the spacer member 40 also serves to support the coil 11 at a position away from the bottom wall portion 22. In this embodiment, the spacer member 40 supports the coil 11 via the support member 42, the magnetic shielding member 44, and the insulating member 46.

[0070] The illustrated spacer members 40 are columnar or needle-shaped, extending in the axial direction of the coil 11, and are arranged apart from each other, that is, scattered as described above. This creates a space between the bottom wall 22 and the support member 42. Various members may be placed between the bottom wall 22 and the support member 42. The component 100 shown by the dashed line in Figures 4 and 5 may be, for example, a capacitor used when constructing a power transmission device. The component 100 is placed in the part of the bottom wall 22 where the spacer members 40 are not present, and in the illustrated example, when viewed in the axial direction of the coil 11, it is located outside the outer peripheral edge 11ep of the coil 11.

[0071] Furthermore, as shown in Figure 5, the spacer member 40, located radially inside the outer peripheral edge 11ep of the coil 11, overlaps with the coil 11, more specifically the conductor 11E, in the axial direction of the coil 11. This reduces the distance of the heat transfer path between the coil 11 and the spacer member 40, making it easier for heat from the coil 11 to be transferred to the spacer member 40. However, the spacer member 40 does not necessarily have to overlap with the coil 11.

[0072] Furthermore, a portion of the spacer member 40 located inside the outer peripheral edge 11ep of the coil 11 is positioned in a range from the innermost turn portion 121 of the multiple turn portions 12n to the largest integer (in the illustrated example, "4") turn portion 124, which is less than or equal to the value obtained by dividing the number of turns of the coil (in the illustrated example, "9") by 2 (in the illustrated example, "4.5"). In the coil 11, the portion closer to the central axis C tends to be hotter than the portion closer to the outer peripheral edge 11ep. Therefore, if more spacer members 40 are positioned closer to the central axis C, the heat from the coil 11 can be more efficiently dissipated to the outside.

[0073] In this embodiment, the number of spacer members 40 located inside the outer peripheral edge 11ep of the coil 11, from the innermost turn portion 121 to the fourth turn portion 124, which is the largest integer turn portion less than or equal to the number of turns (in the illustrated example, "9") divided by 2 (in the illustrated example, "4.5"), is smaller than the number of spacer members 40 arranged in the range from the fifth turn portion 125 to the outermost turn portion 129. However, the former number may be larger than the latter number in order to improve heat dissipation performance. Furthermore, the spacer members 40 may be arranged such that the density of spacer members 40 located in the range from the innermost turn portion 121 to the fourth turn portion 124, which is the largest integer turn portion less than or equal to the number of turns (in the illustrated example, "9") divided by 2 (in the illustrated example, "4.5"), is greater than the density of spacer members 40 arranged in the range from the fifth turn portion 125 to the outermost turn portion 129.

[0074] On the other hand, when viewed in the axial direction of the coil 11, the spacer member 40 is not provided in the radially inward range of the innermost turn portion 121. Heat from the coil 11 is not generated in areas where the coil 11 is not present. In this embodiment, by not providing the spacer member 40 radially inward of the innermost turn portion 121 where the coil 11 is not present, the number and occupied area of ​​spacer members 40 that do not effectively contribute to heat dissipation performance are suppressed.

[0075] The material of the spacer member 40 is not particularly limited, but the spacer member 40 is formed from a material having a thermal conductivity greater than that of a gas such as air or resin (W / m·k). Specifically, the thermal conductivity of the spacer member 40 is 1 W / m·k or higher. Note that the thermal conductivity is the thermal conductivity at 27°C (300K). The spacer member 40 may be formed from aluminum, an aluminum alloy, or other metal. In particular, in this embodiment, the spacer member 40 is made of aluminum, the same material as the bottom wall portion 22 and the side wall portion 23, and is formed simultaneously with the bottom wall portion 22 and the side wall portion 23 by integral molding. The thermal conductivity of the spacer member 40 may be 2 W / m·k or higher, 10 W / m·k or higher, 20 W / m·k or higher, or 40 W / m·k or higher. Note that the thermal conductivity of aluminum is 237 (W / m·k). In the inventor's diligent research, sufficient heat dissipation performance can be achieved if the thermal conductivity of the spacer member 40 is 80 (W / m·k) or higher. Therefore, the thermal conductivity of the spacer member 40 may be 80 (W / m·k) or higher, 100 (W / m·k) or higher, 150 (W / m·k) or higher, or 200 (W / m·k) or higher.

[0076] The thickness of the spacer member 40, i.e., its axial dimension, may be 40 mm or less. Alternatively, the thickness of the spacer member 40 may be 15 mm or more, 20 mm or more, or 25 mm or more. If the thickness of the spacer member 40 is made sufficiently large, it becomes easier to effectively utilize the storage space for the components. However, the dimensions of the spacer member 40 are not particularly limited. Furthermore, the shape of the spacer member 40 is not particularly limited; for example, it may be a block-shaped member such as a rectangular prism or cube, or it may be made of plate material.

[0077] (Support member) The support member 42 is a plate-shaped member that extends along the radial direction of the coil 11. The support member 42 forms a base on which the magnetic shielding member 44, the insulating member 46, and the coil 11 rest. The support member 42 is sheet-like and is sized to overlap all or most of the magnetic shielding member 44, the insulating member 46, and the coil 11 in a plan view. Referring to Figure 4, in this embodiment, in a plan view (i.e., viewed in the axial direction of the coil 11), the support member 42 is smaller than the magnetic shielding member 44, the insulating member 46, and the coil 11, but the support member 42 overlaps most of these magnetic shielding member 44, the insulating member 46, and the coil 11. The support member 42 maintains its extension along the radial direction of the coil 11 by being supported by the spacer member 40.

[0078] Furthermore, the support member 42 has thermal conductivity and transfers heat from the coil 11 to the spacer member 40. The material of the support member 42 is not particularly limited, but the support member 42 is formed from a material having a thermal conductivity greater than that of gases such as air or resin (W / m·k). Specifically, the thermal conductivity of the support member 42 is 1 W / m·k or more. The support member 42 may be formed from a metal such as aluminum or an aluminum alloy. In particular, in this embodiment, the support member 42 is formed from aluminum. The thermal conductivity of the support member 42 may be 2 W / m·k or more, 10 W / m·k or more, 20 W / m·k or more, or 40 W / m·k or more. In particular, the thermal conductivity of the support member 42 may be 80 (W / m·k) or more, 100 (W / m·k) or more, 150 (W / m·k) or more, or 200 (W / m·k) or more. Furthermore, the support member 42 may include a portion formed of, for example, resin, in which the thermal conductivity is partially less than 1 W / m·k. In this case, the thermal conductivity of the support member 42 is determined by the thermal conductivity of the portion of the support member 42 that is 1 W / m·k or higher. When the support member 42 partially includes resin, it is preferable that the proportion of the portion of the support member 42 with a thermal conductivity of 1 W / m·k or higher relative to the entire support member 42 is 30% or more.

[0079] Furthermore, the contact area between the support member 42 and the multiple spacer members 40 should be 25% or less of the area of ​​the support member 42 in a plan view. In this case, an excessive weight increase of the coil component 10A can be avoided.

[0080] (Magnetic shielding member) The magnetic shielding member 44 is provided to suppress magnetic transmission and / or leakage magnetic fields. The magnetic shielding member 44 is a sheet-like structure extending along the radial direction of the coil 11, and is sized to encompass the insulating member 46 and the coil 11 in a plan view, i.e., in the axial direction of the coil 11. The magnetic shielding member 44 is provided between the support member 42 and the coil 11 and the insulating member 46. Therefore, heat from the coil 11 is transferred from the magnetic shielding member 44 to the support member 42, and from the support member 42 to the spacer member 40. Heat dissipation members, such as heat dissipation sheets, may be provided between the magnetic shielding member 44 and the support member 42, and between the magnetic shielding member 44 and the coil 11 and the insulating member 46. Such heat dissipation members are preferably non-magnetic and insulating, and may be, for example, acrylic heat dissipation sheets.

[0081] The magnetic shielding member 44 contains a magnetic material. The magnetic field generated by the coil component 10A spreads in all directions with respect to the central axis C of the coil 11. In this case, the magnetic shielding member 44, being magnetic, can orient the spreading magnetic flux lines toward the central axis C. Furthermore, if the magnetic field generated by the coil component 10A flows toward other surrounding components, it may adversely affect those components. Therefore, the magnetic shielding member 44 is provided to suppress the transmission of magnetic field lines. As a result, the magnetic shielding member 44 can suppress leakage magnetic fields that do not contribute to the generation of current.

[0082] The magnetic shielding member 44 preferably contains a soft magnetic material. More specifically, the magnetic shielding member 44 contains ferrite, preferably soft ferrite. The magnetic shielding member 44 may also contain a nanocrystalline magnetic material.

[0083] As described above, when transmitting power to an electric vehicle, the radius of the coil 11 (the distance from the central axis C to the part furthest in the radial direction) is usually between 200 mm and 350 mm. If the magnetic shielding member 44 contains ferrite, it is generally difficult to form a single ferrite plate of a size that can accommodate the coil 11 with a radius of 200 mm and 350 mm, and to form the magnetic shielding member 44 from a single ferrite plate. Therefore, when forming the magnetic shielding member 44 using ferrite, a sheet-like magnetic shielding member 44 may be formed by arranging multiple small pieces of ferrite plate in a planar manner.

[0084] When using multiple small ferrite plates, they may be held in place by a frame member or the like to prevent their relative positions from shifting. In this case, handling of the magnetic shielding member 44 becomes easier. Furthermore, in a configuration that suppresses relative positional shifting of multiple small ferrite plates, the support state of the coil 11 can be stabilized even when the support member 42 is not used.

[0085] On the other hand, the magnetic shield member 44 may be formed in a manner that allows for a certain degree of relative misalignment of the multiple small ferrite plates. Alternatively, the magnetic shield member 44 may be formed by a collection of multiple small ferrite plates in a separated state. In these configurations, the support state of the coil 11 on the spacer member 40 can be stabilized by using the support member 42. On the other hand, if the support member 42 is not used, the support state of the coil 11 can be stabilized by supporting one ferrite plate with multiple spacer members 40. Furthermore, when the magnetic shield member 44 is constructed with multiple small ferrite plates, it is desirable to arrange the multiple ferrite plates so that adjacent ferrite plates are in contact with each other so that no gaps are formed between them. This suppresses the passage of magnetic flux from the coil 11 through the gaps between adjacent ferrite plates. On the other hand, if gaps are formed between adjacent ferrite plates, it is desirable to directly support the ferrite plates with the spacer members 40 without using the support member 42. In this case, even if the magnetic flux from the coil 11 passes through the gap between adjacent ferrite plates, it is unlikely to reach the spacer member 40, thus suppressing losses.

[0086] Furthermore, when viewed in the axial direction of the coil 11, the support member 42 is located inside the outer edge of the magnetic shield member 44. In other words, when viewed in the axial direction of the coil 11, the magnetic shield member 44 is formed to be sized to encompass the support member 42. Also, when viewed in the axial direction of the coil 11, the support member 42 is rectangular in shape and is located inside the outer edge 11ep of the coil 11, except for the four corners. With these dimensional relationships, the magnetic field generated in the coil 11 is prevented from intersecting the support member 42 and the spacer member 40 via the radially outward direction of the magnetic shield member 44, thereby suppressing magnetic loss and preventing a decrease in the performance of the coil.

[0087] Figure 6 is a table illustrating the relationship between the size difference between the support member 42 and the magnetic shielding member 44 and the Q value. Figure 7 is a graph illustrating the relationship between the size difference between the support member 42 and the magnetic shielding member 44 and the Q value. The size difference between the support member 42 and the magnetic shielding member 44 is the shortest distance from a certain point on the outer edge of the support member 42 to the outer edge of the magnetic shielding member 44, and is the same value over the entire circumference of the outer edge of both the support member 42 and the magnetic shielding member 44. The size difference is an indicator of how small the support member 42 is compared to the magnetic shielding member 44, and is therefore indicated by a "-" in the table in Figure 6. The Q value is calculated through simulation.

[0088] The following conditions were set for the simulation. The maximum length of coil 11 is 570 mm, and the maximum width is 470 mm. The thickness of coil 11 is 1.5 mm. The support member 42 is made of a rectangular aluminum plate with a thickness of 2 mm, and its dimensions in the longitudinal direction were changed to a range of 390 mm to 590 mm, and its dimensions in the short direction to a range of 290 mm to 490 mm, as shown in Figure 6. The magnetic shielding member 44 contains ferrite and is formed in the shape of a rectangular plate with a thickness of 3 mm, having a length of 590 mm and a width of 490 mm.

[0089] As shown in Figure 6, the Q value is 129 when the size difference is 0 mm, 141 when it is -1 mm, 150 when it is -5 mm, 156 when it is -15 mm, 157 when it is -20 mm, 159 when it is -50 mm, and 158 when it is -100 mm. In other words, it can be seen that Q tends to increase as the size difference increases. On the other hand, as shown in Figure 7, when the size difference becomes larger than 15 mm (i.e., when the size difference < -15 mm), it can be seen that the rate of increase in the Q value decreases and tends to saturate.

[0090] The simulation results in Figures 6 and 7 confirm that it is preferable for the support member 42 to be smaller than the magnetic shielding member 44. The dimensional difference in this case may be 5 mm or more, 10 mm or more, or 15 mm or more. On the other hand, the dimensional difference may be 30 mm or less, or 20 mm or less.

[0091] (Insulating material) The insulating member 46 overlaps with the coil 11 in the axial direction of the coil 11. In this state, the insulating member 46 is integrated with the coil 11. The insulating member 46 is sheet-like and is sized to encompass the coil 11 in a plan view.

[0092] As shown in Figures 4 and 5, the insulating member 46 has a spiral-shaped recess 46g that corresponds to the spiral shape of the coil 11. The recess 46g is spiral-shaped when viewed in the axial direction of the coil 11 and is recessed in the axial direction of the coil 11, in other words, in the thickness direction of the insulating member 46. At least a portion of the coil 11 is housed within the recess 46g with its spiral shape aligned with the spiral shape of the recess 46g. More specifically, the recess 46g houses the entire conductor 11E.

[0093] In this embodiment, the conductor 11E does not protrude from the recess 46g and is flush with the insulating member 46. However, a portion of the coil 11 may be housed within the recess 46g so that a portion of the coil 11 protrudes from the recess 46g. Alternatively, the insulating member 46 may not have a recess 46g formed in it, and the coil 11 may be provided on the flat surface of the insulating member 46. Furthermore, the conductor 11E may be embedded in the insulating member 46 without being exposed to the outside.

[0094] The insulating member 46 is welded to the coil 11 in the recess 46g. That is, the coil 11 and the recess 46g are joined by an anchoring effect. The coil 11 and the insulating member 46 are integrated, for example, by hot pressing. At this time, a part of the insulating member 46 enters into the recess on the surface of the coil 11 and then hardens. As a result, the coil 11 and the recess 46g are welded together, and the insulating member 46 becomes integrated with the coil 11.

[0095] In this embodiment, the insulating member 46 contains a glass fiber-reinforced epoxy resin. That is, the insulating member 46 is formed from a material containing epoxy resin as a thermosetting resin (thermosetting material) and glass fibers. When the coil 11 and the insulating member 46 are integrated by hot pressing, the coil 11 is pressed into the forming material of the insulating member 46, forming a spiral-shaped recess 46g. In this case, if the forming material of the insulating member 46 is a glass fiber-reinforced epoxy resin, the epoxy resin softens and flows along the side surface of the coil 11, forming the recess 46g. In this case, the glass fibers suppress excessive flow of the epoxy resin.

[0096] For the reasons stated above, the insulating member 46 and its forming material are preferably made of glass fiber-reinforced epoxy resin. However, the insulating member 46 and its forming material are not particularly limited. For example, they do not need to contain glass fibers. Carbon fibers or the like may be used instead of glass fibers. Polyimide (thermoplastic resin) may be used instead of epoxy resin.

[0097] Furthermore, as shown in Figure 3, the insulating member 46 and the coil 11 integrated with the insulating member 46 are separated from the inner surface of the top wall portion 24 of the case 20. This suppresses the transmission of loads received by the top wall portion 24 to the coil 11, thereby protecting the coil 11. However, the coil 11 and / or the insulating member 46 may be in contact with the inner surface of the top wall portion 24. It is undesirable for the top wall portion 24 to become excessively hot. If a relatively large space is formed between the inner surface of the top wall portion 24 of the case 20 and the coil 11, heat conduction from the coil 11 to the top wall portion 24 is suppressed, and the top wall portion 24 can be prevented from becoming excessively hot. In addition, by suppressing the temperature rise, the thickness of the top wall portion 24 can be reduced, which can suppress a decrease in power transmission characteristics when using the coil component 10A in a power transmission device, for example.

[0098] (Connection terminals) As shown in Figure 2, the first connection terminal 51 is connected to the inner circumference end 11A of the coil 11. The second connection terminal 52 is connected to the outer circumference end 11B of the coil 11. In this embodiment, as shown in Figure 5, the inner lead portion 13i connected to the radially inner end of the turn portion 121 in the conductor 11E forms the inner circumference end 11A of the coil 11. The outer lead portion 13e connected to the radially outer end of the turn portion 129 forms the outer circumference end 11B of the coil 11. The first connection terminal 51 and the second connection terminal 52 can be used, for example, when connecting to a high-frequency current supply unit 1A or a conversion unit 2A. The connection between the first connection terminal 51 and the inner circumference end 11A and the connection between the second connection terminal 52 and the outer circumference end 11B are performed by ultrasonic bonding. However, the connection method is not limited, and for example, connection by conductive adhesive may be employed.

[0099] (Applications of coil components) The coil component 10A according to this embodiment can be used, for example, as a power transmission coil in the power transmission device 1 of the wireless power transmission system S described above, and can also be used as a power receiving coil in the power receiving device 2.

[0100] When a coil component 10A is used as a power transmission coil, the first connection terminal 51 and the second connection terminal 52 are connected to a high-frequency current supply unit 1A or an AC power source as shown in Figure 1. When a high-frequency current is supplied to the coil component 10A, the current can be passed from the first connection terminal 51 to the coil 11, and then from the second connection terminal 52 to the high-frequency current supply unit 1A or the AC power source. Alternatively, the current can be passed from the second connection terminal 52 to the coil 11, and then from the first connection terminal 51 to the high-frequency current supply unit 1A or the AC power source. This makes it possible to generate a magnetic field including magnetic field lines along the central axis of the coil 11.

[0101] On the other hand, when using coil component 10A as the power receiving coil, a high-frequency current can be generated in the coil 11 by receiving a magnetic field including magnetic field lines along the central axis of the coil 11. This high-frequency current can then be supplied to an external device from the first connection terminal 51 or the second connection terminal 52.

[0102] (Effects / Actions) The coil component 10A described above comprises a spiral-shaped coil 11, a case 20 as a housing member for housing the coil 11, and a spacer member 40 as a heat-conducting member for transferring heat from the coil 11 to the inner surface of the case 20. The spacer member 40 is located in the radial direction of the coil 11, within the range inside the outer peripheral edge 11ep of the coil 11.

[0103] In this configuration, the spacer members 40 transfer heat from the coil 11 to the case 20 along the axial direction of the coil 11, thereby reducing the distance of the heat transfer path. Consequently, heat from the coil 11 can be efficiently dissipated. In particular, when viewed in the axial direction of the coil 11, multiple spacer members 40 are scattered within the area inside the outer peripheral edge 11ep of the coil 11. This improves heat dissipation performance.

[0104] Furthermore, the spacer member 40 functions as a thermally conductive member for dissipating heat from the coil 11, and also functions to maintain a state in which the coil 11 and the inner surface of the case 20 are separated. In this configuration, by maintaining the position of the coil 11 at a desired position with the spacer member 40, good heat dissipation performance can be ensured while improving transmission efficiency when used in a power transmission system.

[0105] Furthermore, the spacer member 40 overlaps with the coil 11 in the axial direction of the coil 11. In this configuration, heat is efficiently transferred from the coil 11 to the spacer member 40, thereby improving heat dissipation performance.

[0106] Furthermore, the coil 11 includes a plurality of turn sections 12n arranged radially outward from the central axis C of the spiral shape, and at least a portion of the plurality of spacer members 40 are positioned in the range from the innermost turn section 121 of the plurality of turn sections 12n to the turn section 124 of the largest integer position (4) that is less than or equal to the value obtained by dividing the number of turns of the coil 11 (9) by 2 (4.5). With this configuration, the heat from the coil 11, which tends to become hot near the central axis of the coil 11, can be efficiently transferred to the spacer members 40, thereby improving heat dissipation performance.

[0107] Furthermore, when viewed in the axial direction of the coil 11, the spacer member 40 is not provided in the radially inward range of the innermost turn portion 121. In this configuration, by avoiding the placement of the spacer member 40 in areas where the coil 11 does not exist, good heat dissipation performance can be ensured while suppressing the number and occupied area of ​​the spacer member 40.

[0108] Furthermore, the coil component 10A further includes a plate-shaped support member 42 extending along the radial direction of the coil 11. The support member 42 is thermally conductive and is provided between the spacer member 40 and the coil 11. In this configuration, the coil 11 can be supported by the spacer member 40 via the support member 42, thus enabling stable support of the coil 11. In addition, the variety of heat transfer paths from the coil 11 to the case 20 is increased, ensuring good heat dissipation performance.

[0109] Furthermore, the coil component 10A further includes a magnetic shielding member 44, which is a sheet-like magnetic material extending along the radial direction of the coil 11, and the magnetic shielding member 44 is provided between the support member 42 and the coil 11. In this configuration, the magnetic field generated by the coil 11 is suppressed from interfering with the spacer member 40 and the support member 42, thereby suppressing a decrease in coil performance.

[0110] Furthermore, the support member 42 is located inward of the outer edge of the magnetic shielding member 44 in the radial direction of the coil 11. In this configuration, the magnetic field generated by the coil 11 is effectively suppressed from reaching the support member 42 via the outer edge of the magnetic shielding member 44, thus effectively suppressing a decrease in coil performance.

[0111] Furthermore, the support member 42 is rectangular in shape and, except for the four corners, is located inside the outer peripheral edge 11ep of the coil 11 in the radial direction of the coil 11. In this configuration, the magnetic field generated by the coil 11 is more effectively suppressed from reaching the support member 42 via the outer peripheral edge of the magnetic shield member 44, thereby more effectively suppressing the deterioration of the coil performance.

[0112] <Second Embodiment> Next, a coil component 10B according to the second embodiment will be described. Figure 8 is a plan view of the coil component 10B. Components in this embodiment that are the same as those in the first embodiment are denoted by the same reference numerals, and redundant explanations are omitted. In Figure 8, the support member 42 is shown by a solid line, and the coil 11 and insulating member 46 that overlap the support member 42 are shown by dashed lines. Also, the case 20 and magnetic shielding member 44 are not shown.

[0113] In this embodiment, the configuration of the support member 42 differs from that of the first embodiment. As shown in Figure 8, the support member 42 includes a central portion 42A that coincides with the central axis C of the coil in the axial direction of the coil 11, and an outer frame portion 42B that surrounds the central portion 42A and connects to the central portion 42A. The thermal conductivity of the central portion 42A is greater than that of the outer frame portion 42B. The central portion 42A is made of aluminum, and the outer frame portion 42B is made of polycarbonate. The material of the central portion 42A is not particularly limited as long as its thermal conductivity is 1 W / m·k or more, and may be made of an aluminum alloy or the like. The material of the outer frame portion 42B is also not particularly limited, but it is preferable that it is a material that has good heat resistance and is lightweight. The material of the outer frame portion 42B may be acrylic resin or the like.

[0114] The central portion 42A and the outer frame portion 42B may be integrated by fitting the outer edge of the central portion 42A into the inner circumference of the outer frame portion 42B. In this case, the central portion 42A and the outer frame portion 42B may be joined via adhesive or a bonding agent. The central portion 42A is rectangular in plan view, and the outer frame portion 42B is rectangular in plan view, but their shapes may also be circular, circular, or other shapes.

[0115] When viewed in the axial direction of the coil 11, the ratio of the area of ​​the central portion 42A to the total area of ​​the support member 42 is 30% or more, and preferably 50% or more. Furthermore, when viewed in the axial direction of the coil 11, the central portion 42A has a size that encompasses the range from the innermost turn portion 121 of the multiple turn portions 12n to the turn portion 124 of the largest integer position (4) that is less than or equal to the value obtained by dividing the number of turns of the coil 11 (9) by 2 (4.5).

[0116] According to the coil component 10B of the second embodiment described above, the heat from the coil 11, which tends to become hot near the central axis C, can be efficiently transferred to the spacer member 40 via the central portion 42A. This ensures good heat dissipation performance of the coil component 10B while reducing weight and material costs in the outer frame portion 42B.

[0117] <Third Embodiment> Next, a coil component 10C according to the third embodiment will be described. Figure 9 is a cross-sectional view of the coil component 10C. Components in this embodiment that are the same as those in the first and second embodiments are denoted by the same reference numerals, and redundant explanations are omitted.

[0118] As shown in Figure 9, in the coil component 10C of this embodiment, the conductor 11E in the coil 11 is embedded in the insulating member 46 without being exposed to the outside. With this configuration, warping of the coil 11 can be effectively suppressed.

[0119] <Fourth Embodiment> Next, a coil component 10D according to the fourth embodiment will be described. Figure 10 is a cross-sectional view of the coil component 10D. Components in this embodiment that are the same as those in the first to third embodiments are denoted by the same reference numerals, and redundant explanations are omitted.

[0120] As shown in Figure 10, in the coil component 10D of this embodiment, the coil 11 includes a first coil 11-1 and a second coil 11-2. The insulating member 46 has a three-layer structure and includes a first insulating member 46-1, a second insulating member 46-2, and a third insulating member 46-3. The first coil 11-1, the second coil 11-2, the first insulating member 46-1, the second insulating member 46-2, and the third insulating member 46-3 are integrated together. The conductors 11E contained in the first coil 11-1 and the second coil 11-2 are embedded in the insulating member 46 (46-1 to 46-3) in a state where they are not exposed to the outside. The first coil 11-1 and the second coil 11-2 overlap in the axial direction and are held apart in the axial direction. The first coil 11-1, more precisely, has its conductor 11E sandwiched between the first insulating member 46-1 and the second insulating member 46-2. The second coil 11-2, more precisely, has its conductor 11E sandwiched between the second insulating member 46-2 and the third insulating member 46-3. The first insulating member 46-1 is in contact with the magnetic shielding member 44.

[0121] The first coil 11-1 and the second coil 11-2 may be connected in series or in parallel. In Figure 10, the boundary between the first insulating member 46-1 and the second insulating member 46-2 is shown near the midpoint in the thickness direction of the first coil 11-1. The boundary between the second insulating member 46-2 and the third insulating member 46-3 is shown near the midpoint in the thickness direction of the second coil 11-2. These boundaries may not be visible when the first insulating member 46-1, the second insulating member 46-2, and the third insulating member 46-3 are integrated, but they are clearly shown in Figure 16 for the sake of explanation.

[0122] In the coil component 10D according to the fourth embodiment described above, warping that may occur in the integrated structure of the first coil 11-1, the second coil 11-2, the first insulating member 46-1, the second insulating member 46-2, and the third insulating member 46-3 can be effectively suppressed. Furthermore, by increasing the total amount of coil material, the amount of heat generated per unit area of ​​the coil can be suppressed.

[0123] <Fifth Embodiment> Next, a coil component 10E according to the fifth embodiment will be described. Figure 11 is a cross-sectional view of the coil component 10E. Components in this embodiment that are the same as those in the first to fourth embodiments are denoted by the same reference numerals, and redundant explanations are omitted.

[0124] As shown in Figure 11, in the coil component 10E of this embodiment, no support member 42 is provided, and the spacer member 40 is in direct contact with the magnetic shield member 44. The spacer member 40 and the magnetic shield member 44 may be electrically insulated. The spacer member 40 may be in contact with the magnetic shield member 44 via an insulating layer. The insulating layer may be formed, for example, by curing a resin.

[0125] In the coil component 10E according to the fifth embodiment described above, the heat from the coil 11 is more easily transferred to the spacer member 40, thereby improving heat dissipation performance. In addition, the thickness of the coil component 10E can be reduced.

[0126] <Sixth Embodiment> Next, a coil component according to the sixth embodiment will be described. Figure 12 is a cross-sectional view of the coil component according to the sixth embodiment. Components in this embodiment that are the same as those in the first to fifth embodiments are denoted by the same reference numerals, and redundant explanations are omitted.

[0127] In this embodiment, a first heat dissipation member 71 and a second heat dissipation member 72 are added to the configuration of the first embodiment. The first heat dissipation member 71 is provided between the magnetic shielding member 44 and the coil 11 and insulating member 46, and the second heat dissipation member 72 is provided between the magnetic shielding member 44 and the support member 42.

[0128] The first heat dissipation member 71 and the second heat dissipation member 72 are formed in a sheet shape, but their shape is not particularly limited. For example, the first heat dissipation member 71 and the second heat dissipation member 72 may each be composed of multiple blocks or plates and arranged in a dispersed manner. The first heat dissipation member 71 and the second heat dissipation member 72 are preferably non-magnetic and insulating, and may be, for example, acrylic heat dissipation sheets or heat dissipation blocks. The thermal conductivity of the first heat dissipation member 71 and the second heat dissipation member 72 may be 1 W / m·k or higher, 2 W / m·k or higher, or 3 W / m·k or higher.

[0129] <Seventh Embodiment> Next, a coil component according to the seventh embodiment will be described. Figure 13 shows a coil component according to the seventh embodiment. Components in this embodiment that are the same as those in the first to sixth embodiments are denoted by the same reference numerals, and redundant explanations are omitted.

[0130] As shown in Figure 13, in this embodiment, the magnetic shielding member 44 is composed of multiple small pieces of ferrite plates 44P as magnetic plate material. The multiple ferrite plates 44P are arranged adjacent to each other on the support member 42. In this example, gaps are formed between adjacent ferrite plates 44P.

[0131] In this embodiment, since the magnetic shielding member 44 is composed of multiple small ferrite plates 44P, the overall size of the magnetic shielding member 44 can be easily increased. The multiple ferrite plates 44P may be arranged so that no gaps are formed between adjacent ferrite plates 44P. In this case, the magnetic flux from the coil 11 is less likely to flow to the support member 42, and a decrease in efficiency can be suppressed.

[0132] <Eighth Embodiment> Next, a coil component according to the eighth embodiment will be described. Figure 14 shows a coil component according to the eighth embodiment. Components in this embodiment that are the same as those in the first to seventh embodiments are denoted by the same reference numerals, and redundant explanations are omitted.

[0133] As shown in Figure 14, in this embodiment, the magnetic shielding member 44 is composed of multiple small pieces of ferrite plates 44P as magnetic plate material. Each of the multiple ferrite plates 44P is supported by a spacer member 40 and arranged adjacent to one another. A gap is formed between adjacent ferrite plates 44P.

[0134] If a gap is formed between adjacent ferrite plates 44P, it is preferable to directly support the ferrite plates with the spacer member 40 instead of using the support member 42. In this case, even if the magnetic flux from the coil 11 passes through the gap between adjacent ferrite plates 44P, it is difficult for it to reach the spacer member 40, and losses can be suppressed.

[0135] Table 1 below shows the results of simulations determining the Q-value and loss in the configuration of Figure 13 (the seventh embodiment) and the Q-value and loss in the configuration of Figure 14 (the embodiment of Figure 8). Under the simulation conditions, the upper limits for dimensions and number are the same for both configurations, except that the support member 42 is not provided in the configuration of Figure 14.

[0136] [Table 1]

[0137] The simulation results in Table 1 show that the Q value of the configuration in Figure 14 is higher than that of the configuration in Figure 13. Furthermore, the loss of the configuration in Figure 14 is smaller than that of the configuration in Figure 13. These simulation results confirm that, when a gap is formed between adjacent ferrite plates 44P, it is desirable to directly support the ferrite plates with the spacer member 40 from the viewpoint of reducing loss.

[0138] While embodiments of this disclosure have been described above, various modifications may be made to the embodiments described above. Such modifications may also fall within the technical scope of this disclosure. [Explanation of symbols]

[0139] S...Power transmission system 1... Power transmission equipment 1A…High-frequency current supply unit 2... Power receiving device 2A...Conversion section 10, 10A, 10B, 10C, 10D, 10E… Coil components 11… Coil 11E... Conductor 11ep…Outer edge 12n, 121, 122, ..., 128, 129... Turn section 20...cases 22...Bottom wall 23... Side wall section 24…Top wall part 40…Spacer member 42…Support member 42A…Central part 42B... Outer frame 44…Magnetic shielding member 46…Insulating material

Claims

1. A spiral-shaped coil, A storage member for housing the aforementioned coil, A heat-conducting member that transfers the heat of the coil to the inner surface of the housing member, A support member provided between the heat-conducting member and the coil, The system comprises a magnetic member provided between the support member and the coil, The heat-conducting member is located in the radial direction of the coil, within the area inside the outer edge of the coil, and overlaps with the magnetic member in the axial direction of the coil. The support member is located inward of the outer peripheral edge of the magnetic member in the radial direction. A coil component in which, when viewed in the axial direction of the coil, the magnetic member is formed to be sized to encompass the support member.

2. The coil component according to claim 1, wherein the heat-conducting member is a spacer member that maintains a state in which the coil and the inner surface of the housing member are separated.

3. The coil component according to claim 1 or 2, wherein the heat conductive member overlaps with the coil in the axial direction of the coil.

4. Multiple thermal conductive members are provided. The coil component according to any one of claims 1 to 3, wherein the plurality of heat-conducting members are scattered in the radial direction within the area inward of the outer edge of the coil.

5. The coil includes a plurality of turns arranged radially outward from the central axis of the spiral shape, The coil component according to claim 4, wherein at least a portion of the plurality of heat-conducting members are arranged in a range from the innermost turn of the plurality of turn portions to the largest integer turn portion that is less than or equal to the number of turns of the coil divided by 2, counting from the innermost turn portion.

6. The coil component according to claim 5, wherein the heat conductive member is not provided in the radially inward range of the innermost turn portion.

7. The coil component according to any one of claims 1 to 6, wherein the support member is plate-shaped extending along the radial direction and has thermal conductivity.

8. The support member includes a central portion that coincides with the central axis of the coil in the axial direction of the coil, and an outer frame portion that surrounds the central portion and connects to the central portion. The coil component according to claim 7, wherein the thermal conductivity of the central portion is greater than that of the outer frame portion.

9. The coil component according to claim 7 or 8, wherein the magnetic member is in the form of a sheet extending along the radial direction.

10. The coil component according to claim 1, wherein the support member is rectangular in shape and located inward of the outer edge of the coil in the radial direction, except for the four corners.

11. The coil component according to any one of claims 7 to 10, wherein the thermal conductivity of the support member is 1 W / m·k or more.

12. The coil component according to any one of claims 1 to 11, wherein the thermal conductivity of the thermal conductive member is 1 W / m·k or more.

13. A power transmission device comprising a coil component according to any one of claims 1 to 12.

14. A power receiving device comprising a coil component according to any one of claims 1 to 12.

15. It comprises a power transmission device and a power receiving device, A power transmission system in which at least one of the power transmission device and the power receiving device comprises a coil component according to any one of claims 1 to 12.

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