Wireless power supply unit for vehicle and wireless power supply system for vehicle

Abstract

A wireless power supply unit (100) for vehicles which wirelessly supplies power to a vehicle (60) and includes a plurality of power transmission coils (31) and a lower housing (41) which is positioned inside a road (50) and is equipped with said plurality of power transmission coils, wherein the plurality of power transmission coils (31) are arranged along one or more directions among a vehicle travel direction (D1) within a plane in the lower housing which is parallel to the road, and a direction (D2) which is perpendicular to said travel direction. The plurality of power transmission coils (31) in the wireless power supply unit (100) for vehicles may be arranged along a direction which is perpendicular to the vehicle travel direction on the road.

Description

[Technical field]

[0001] The present invention relates to a wireless power feeding unit for a vehicle and a wireless power feeding system for a vehicle. [Background technology]

[0002] In recent years, wireless power supply systems have been developed that wirelessly supply power from a power supply device to a moving body such as a moving vehicle (hereinafter, "vehicle, etc."). For example, Patent Document 1 discloses an example of installing a wireless power supply device inside a road. In wireless power supply to a moving vehicle, when a vehicle, etc. equipped with a power receiving coil passes over a power transmitting coil installed inside the road, power is supplied wirelessly from the power transmitting coil. The power received by the power receiving coil is charged into a secondary battery, etc. mounted on the vehicle, etc. By supplying power while the vehicle is moving, it is possible to extend the driving distance while suppressing an increase in the capacity of the secondary battery.

[0003] Generally, the closer the horizontal positions of the central axes of the power transmitting coil and power receiving coil that supply power wirelessly, the better the transmission efficiency, so the positioning of the power receiving coil when installed on the road must be done accurately. Also, the closer the distance in the thickness direction of the coils, the better the transmission efficiency, so the positioning of the depth at which the power receiving coil is installed on the road must be done accurately. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-12377

[0005] To install a power transmission coil inside a road, it is necessary to excavate the road. To obtain a certain transmission efficiency, the power transmission coil needs to be installed at a specified position and depth inside the road. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a wireless power supply unit for a vehicle that enables a power transmission coil to be easily installed on a road. [Means for solving the problem]

[0007] According to one embodiment of the present invention, there is provided a wireless power supply unit for a vehicle that wirelessly supplies power to a vehicle, the wireless power supply unit including a plurality of power transmission coils and a lower housing that is installed inside a road and includes the plurality of power transmission coils, the plurality of power transmission coils being arranged along at least one of the vehicle travel direction and a direction perpendicular to the travel direction on a plane of the lower housing that is parallel to the road.

[0008] According to one embodiment of the present invention, a wireless power supply system for a vehicle includes the above-described wireless power supply unit for a vehicle, a control device that supplies power to the transmission coil, a cable that supplies power from the control device to the wireless power supply unit for a road, and a sensor that detects the intrusion of a vehicle into a predetermined area, and the control device controls whether or not to supply power to the transmission coil based on an output from the sensor. Effect of the Invention

[0009] By using one embodiment of the present invention, it is possible to provide a wireless power feeding unit for a vehicle and a wireless power feeding system for a vehicle that enable a power transmission coil to be easily installed on a road. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a wireless power feeding system for a vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of a wireless power feeding system for a vehicle according to one embodiment of the present invention, as viewed from the side. [Diagram 3] FIG. 3 is a schematic diagram showing electrical connections in a wireless power feeding system for a vehicle according to one embodiment of the present invention. [Figure 4A] FIG. 4A is a schematic cross-sectional view showing a method for installing and constructing a wireless power feeding system for a vehicle according to an embodiment of the present invention. [Figure 4B] FIG. 4B is a schematic cross-sectional view showing a method for installing and constructing the wireless power feeding system for a vehicle according to one embodiment of the present invention. [Figure 4C] FIG. 4C is a schematic cross-sectional view showing a method for installing and constructing a wireless power feeding system for a vehicle according to an embodiment of the present invention. [Figure 4D] FIG. 4D is a schematic cross-sectional view showing a method for installing and constructing a wireless power feeding system for a vehicle according to an embodiment of the present invention. [Figure 4E] FIG. 4E is a schematic cross-sectional view showing a method for installing and constructing a wireless power feeding system for a vehicle according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic diagram showing electrical connections in a wireless power feeding system for a vehicle according to one embodiment of the present invention. [Figure 6] FIG. 6 is a schematic cross-sectional view of a wireless power feeding system for a vehicle according to an embodiment of the present invention. [Figure 7A] FIG. 7A is a top view of an upper housing according to one embodiment of the present invention. [Figure 7B] FIG. 7B is a side view of a protrusion according to one embodiment of the present invention. [Figure 7C] FIG. 7C is a top view of the upper housing according to one embodiment of the present invention. [Figure 8A] FIG. 8A is a side view of an upper housing according to one embodiment of the present invention. [Figure 8B] FIG. 8B is a side view of the upper housing according to one embodiment of the present invention. [Figure 9] FIG. 9 is a top view of the upper housing according to one embodiment of the present invention. [Figure 10A] FIG. 10A is a side cross-sectional view of a housing according to one embodiment of the present invention. [Figure 10B] FIG. 10A is a top cross-sectional view of a housing according to one embodiment of the present invention. [Figure 11A] FIG. 11A is a cross-sectional view of a support body according to one embodiment of the present invention as viewed from the upper housing side. [Figure 11B] FIG. 11B is a schematic diagram of a support according to one embodiment of the present invention as viewed from the side. [Figure 11C] FIG. 11C is a side cross-sectional view of a housing according to one embodiment of the present invention. [Figure 11D] FIG. 11D is an enlarged view of a main portion of FIG. 12C. [Figure 11E] FIG. 11E is a cross-sectional view of the support body according to one embodiment of the present invention as viewed from the upper housing side. [Figure 12A] FIG. 12A is a schematic diagram of a support according to one embodiment of the present invention as viewed from the side. [Figure 12B] FIG. 12B is a cross-sectional view of the support body according to one embodiment of the present invention as viewed from the upper housing side. [Figure 12C] FIG. 12C is a cross-sectional side view of the housing and support according to one embodiment of the present invention. [Figure 12D] FIG. 12D is a cross-sectional view of the support body according to one embodiment of the present invention as viewed from the upper housing side. [Figure 13] FIG. 13 is a top view of the lower housing according to one embodiment of the present invention. [Figure 14] FIG. 14 is a schematic cross-sectional view of a wireless power feeding system for a vehicle according to one embodiment of the present invention as viewed from the side. [Figure 15A] FIG. 15A is a detailed cross-sectional view of an end portion of a lower housing according to one embodiment of the present invention. [Figure 15B] FIG. 15B is a detailed cross-sectional view of an end portion of a lower housing according to one embodiment of the present invention. [Figure 15C] FIG. 15C is a detailed cross-sectional view of an end portion of a lower housing according to one embodiment of the present invention. [Figure 15D] FIG. 15D is a detailed top view of an end of the lower housing in accordance with one embodiment of the present invention. [Figure 15E] FIG. 15E is a detailed top view of an end of the lower housing in accordance with one embodiment of the present invention. [Figure 16]FIG. 16 is a schematic cross-sectional view of a wireless power feeding system for a vehicle according to one embodiment of the present invention as viewed from the side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different forms, and should not be interpreted as being limited to the description of the embodiments exemplified below. The drawings may be schematic in order to make the explanation clearer, but they are merely examples and do not limit the interpretation of the present invention.

[0012] Furthermore, the letters "first" and "second" attached to each element are convenient labels used to distinguish each element, and have no further meaning unless otherwise specified. In the drawings referred to in this embodiment, the same parts or parts having similar functions are given the same or similar symbols (symbols consisting of the number xxx followed by A, B, or 1, 2, etc.), and repeated explanations may be omitted. Also, some of the configuration may be omitted from the drawings. In addition, if a person having ordinary knowledge in the field to which the present invention belongs can recognize the above, no special explanation will be given.

[0013] First Embodiment A wireless power feeding system for a vehicle according to a first embodiment of the present invention will be described in detail with reference to the drawings.

[0014] (1-1. Configuration of vehicle wireless power supply system) Fig. 1 is a schematic diagram showing the configuration of a wireless power feeding system for a vehicle (hereinafter, referred to as a power feeding system 10). Fig. 2 is a schematic cross-sectional view of the power feeding system 10. As shown in Figs. 1 and 2, the power feeding system 10 includes a control device 20 and a plurality of power transmitting coil units 30. The control device 20 and the power transmitting coil units 30 are electrically connected by a cable 15.

[0015] The control device 20 converts the AC power supplied from the branch cable into a predetermined frequency and controls the power transmission process to the power transmission coil unit 30. The control device 20 uses at least one of an inverter, a microcomputer, a CPU (Central Processing Unit), and other arithmetic processing devices. The inverter converts the frequency of the power to be transmitted, for example, 85 KHz. The control device 20 (also called an inverter box) is provided on the side of the road 50 (for example, the sidewalk 55). Power is supplied to the control device 20 from, for example, the branch cable.

[0016] The multiple power transmitting coil units 30 are housed in a housing 40 and are embedded inside (underground) the road 50. The multiple power transmitting coil units 30 and the housing 40 may be collectively referred to as a vehicle wireless power supply unit 100. Specifically, the second power transmitting coil unit 30-2 is arranged in a first direction D1 indicating the running direction of the vehicle 60 (the direction in which the road 50 extends) with respect to the first power transmitting coil unit 30-1. The third power transmitting coil unit 30-3 is arranged in a second direction D2 perpendicular to the first direction with respect to the first power transmitting coil unit. The fourth power transmitting coil unit 30-4 is arranged in the second direction with respect to the second power transmitting coil unit 30-2 and in the first direction with respect to the third power transmitting coil unit 30-3. When it is not necessary to separately describe each power transmitting coil unit, they will be described as a power transmitting coil unit 30.

[0017] The power transmitting coil unit 30 includes a power transmitting coil 31, a resonant capacitor 33, and a case 39. In the power transmitting coil unit 30, the power transmitting coil 31 and the resonant capacitor 33 form an LC resonant circuit.

[0018] As shown in FIG. 2, the power transmission coil 31 is installed at a predetermined depth underground 52 from the surface of the road 50. When the power receiving coil 61 provided on the vehicle 60 traveling on the road 50 is placed on the power transmission coil unit 30, the power transmission coil 31 and the power receiving coil 61 face each other. In this case, the power transmission efficiency can be increased by making the distance between the power receiving coil 61 and the power transmission coil 31 mounted on the vehicle 60 as close as possible. Specifically, the distance between the power transmission coil 31 and the power receiving coil 61 is preferably 5 centimeters or more and 50 centimeters or less. More preferably, the distance between the power transmission coil 31 and the power receiving coil 61 is 3 centimeters or more. When high-frequency power is supplied to the power transmission coil 31 facing the power receiving coil 61, a magnetic flux (AC magnetic flux) is generated from the power transmission coil 31 toward the power receiving coil 61 by electromagnetic induction. At this time, an induced electromotive force is generated in the power receiving coil 61. As a result, power can be wirelessly transmitted from the power transmission coil 31 to the power receiving coil 61.

[0019] The electric power received by the power receiving coil 61 is stored in a battery 63 mounted on the vehicle 60. A lithium ion battery is used as the battery 63. Note that, in addition to a lithium ion battery, other rechargeable batteries such as a nickel metal hydride battery may be used as the battery 63. The battery 63 also includes a battery that uses a capacitor as a power storage body.

[0020] 1, the power transmitting coil 31 has a circular ring shape with a hollow center. The power transmitting coil 31 may have a spiral shape with a conductor wound around it. The power transmitting coil 31 may also be formed into a plate shape by winding a conductor.

[0021] Copper or a copper alloy containing oxygen-free copper is used as the material for the conductor of the power transmission coil 31. The material of the power transmission coil 31 is not limited to copper, and aluminum or other metal materials or alloy materials thereof may be used.

[0022] The power transmission coil 31 may be, for example, a single wire, a plurality of single wires twisted together (Litz wire), or a plurality of single wires bundled together. The power transmission coil 31 may also be an enameled wire in which a conductor is covered with a synthetic resin material and insulated. Examples of the synthetic resin material that can be used to cover the conductor include polyurethane resin, polyester resin, polyimide resin, and polyamide resin.

[0023] The power transmitting coil 31 may be a so-called double-wound coil. When the power transmitting coil 31 is a double-wound coil, each wire end 37 of the power transmitting coil 31 can be located outside the winding, and the thickness of the power transmitting coil 31 can be reduced.

[0024] The case 39 is provided to house the power transmitting coil 31 and the resonant capacitor 33 therein. The case 39 is integrally formed so as to prevent any gap from being formed between the power transmitting coil 31 and the resonant capacitor 33. If any gap is formed between the case 39 and the power transmitting coil 31 and the resonant capacitor 33, a filler may be appropriately disposed therein.

[0025] The housing 40 includes a lower housing 41 and an upper housing 43. The housing 40 is attached by placing the upper housing 43 on the lower housing 41 and then fastening them together with fastening members such as screws. The upper housing 43 and the lower housing 41 may be attached by bonding them together using an adhesive.

[0026] The lower housing 41 defines the position of the power transmitting coil unit 30. The lower housing 41 is configured in a flat plate shape. The lower housing 41 has a bottom surface portion 411 that is provided in a flat shape. In this embodiment, the four power transmitting coil units 30 are arranged on the same plane, which is the bottom surface portion 411 of the lower housing 41. The area of ​​the lower housing 41 where each power transmitting coil unit 30 is arranged may be recessed from the surrounding area for positioning. In addition, a protrusion for positioning the power transmitting coil unit 30 may be provided around the area of ​​the lower housing 41 where each power transmitting coil unit 30 is arranged. The power transmitting coil unit 30 is installed by being fastened to the lower housing 41 by a fastening member such as a screw.

[0027] The lower housing 41 is formed of a synthetic resin material. It is desirable that the material of the lower housing 41 has little effect on the electric field and magnetic field formed by wireless power supply from the power transmitting coil 31 to the power receiving coil 61, and is also little changed in shape due to temperature changes. The material of the lower housing 41 is preferably one that has little thermal expansion between, for example, -30°C and 120°C. The material of the lower housing 41 is, for example, polycarbonate resin. Alternatively, the material of the lower housing 41 may be polypropylene resin.

[0028] The lower housing 41 may be provided with wiring holes 411a penetrating the bottom surface 411 from the surface on which the power transmitting coil 31 is installed to the opposite surface. By inserting the wiring holes 411a, the wire ends 37 of the power transmitting coil units 30 can be connected to the cables 15 outside the housing 40. The wire ends 37 are connected to the cables 15 via connection terminals 35 (also called connectors). The use of the connection terminals 35 can facilitate the connection work.

[0029] Upper housing 43 has a structure with high load-bearing capacity. Upper housing 43 has a top surface portion 431 and a side surface portion 433. In this example, upper housing 43 has the same shape as bottom surface portion 411 of lower housing 41 when viewed from above. Side surface portion 433 is fastened to lower housing 41 using a fastening member (e.g., a screw).

[0030] The upper housing 43 can be made of the same material as the lower housing 41. That is, it is desirable that the material of the upper housing 43 has little effect on the electric field and magnetic field formed by wireless power supply. It is also desirable that the material of the upper housing 43 has little change in shape due to temperature change. It is preferable that the material of the upper housing 43 has little thermal expansion between -30°C and 120°C. The material of the upper housing 43 is, for example, polycarbonate resin. It is also possible to use polypropylene resin as the material of the upper housing 43.

[0031] Fig. 3 is a schematic diagram showing electrical connections in the power supply system 10. As shown in Fig. 3, each power transmission coil unit 30 in a housing 40 of the power supply system 10 is connected to a connection terminal 35. The connection terminal 35 of the housing 40 and the connection terminal 25 of the control device 20 are connected via a cable 15. That is, in the power supply system 10 shown in Fig. 3, the number of cables 15 is the same as the number of power transmission coil units 30. Note that the cable 15 is shown as one line in Fig. 3 to show a connection path, but specifically, one line includes two cables.

[0032] (1-2. Layout and Construction Method of Power Supply System 10) FIG. 4 is a cross-sectional view showing a method of arranging and constructing the power supply system 10. First, as shown in FIG. 4A, the control device 20 is installed at a predetermined position (first position P1) on the side of the road 50 (sidewalk 55) (S110). Also, in FIG. 4A, a second position (second position P2) of the road corresponding to the installation position P1 of the control device 20 is excavated. At this time, the road 50 is excavated to a depth sufficient to bury the housing 40 and the cable 15 in the road 50. Next, as shown in FIG. 4B, the cable 15 is installed in the ground 52 (S120). The cable 15 may be buried so that it is appropriately fixed while a part of it is exposed above ground.

[0033] 4C, the lower housing 41 is placed in the ground (S130). At this time, the power transmitting coil unit 30 is placed in the lower housing 41 in advance. The cable 15 is connected to the connection terminal 35. Also, at this time, the cable 15 is connected to the connection terminal 35 through a wiring hole 411a provided in a bottom surface portion 411 of the lower housing 41. Note that the power transmitting coil unit 30 may be placed after the lower housing 41 is placed in the ground 52.

[0034] 4D, the upper housing 43 and the filler 45 are attached to the lower housing 41 in which the power transmitting coil unit 30 is disposed (S140). Note that the filler 45 may be filled in after the upper housing 43 is installed in the lower housing 41 in which the power transmitting coil unit 30 is disposed.

[0035] Finally, as shown in FIG. 4E, the top and sides of the housing 40 are filled with soil, gravel, concrete, etc., and the road 50 is paved with concrete or asphalt mixture (S150). This completes the installation process for the wireless power supply system. The above-mentioned installation method may be modified as appropriate. The housing 40 may be installed underground after the upper housing 43 is attached on the lower housing 41 on the ground.

[0036] During road construction, vehicle traffic is suspended on the road subject to construction. It is desirable to keep the road construction period short. In the case of this embodiment, the positions at which the multiple power transmitting coil units 30 are arranged are determined in advance on the lower housing 41. Therefore, by using this embodiment, the multiple power transmitting coils 31 can be positioned more easily and simply than when the power transmitting coil units 30 are each arranged underground. This allows the installation of the power transmitting coil units 30 on the road to be completed in a short time. In other words, the time required for closing the road to install the power transmitting coil units 30 can be shortened.

[0037] <Second embodiment> In this embodiment, a power supply system having a different configuration from that of the first embodiment will be described. Specifically, a power supply system having a different configuration of a connection terminal will be described.

[0038] FIG. 5 is a schematic diagram showing electrical connections in the power supply system 10A. As shown in FIG. 5, in the power supply system 10A, the first power transmission coil unit 30-1 and the third power transmission coil unit 30-3 are connected in parallel and connected to a first common terminal 35A-1. The second power transmission coil unit 30-2 and the fourth power transmission coil unit 30-4 are connected in parallel and connected to a second common terminal 35A-2. The first common connection 35A-1 of the housing 40 and the connection terminal 25A-1 of the control device 20, and the first common connection 35A-2 of the housing 40 and the connection terminal 25A-2 of the control device 20 are connected by a cable 15. That is, in the power supply system 10A shown in FIG. 5, the number of cables 15 is less than the number of power transmission coils 31. The first power transmission coil unit 30-1 and the third power transmission coil unit 30-3 are controlled at the same timing by a single control of the control device 20. The same is true for the second power transmitting coil unit 30-2 and the fourth power transmitting coil unit 30-4. The first power transmitting coil unit 30-1 and the third power transmitting coil unit 30-3 correspond to the rear wheel side, and the second power transmitting coil unit 30-2 and the fourth power transmitting coil unit 30-4 correspond to the front wheel side. In the present embodiment, the number of cables 15 and connection terminals 35 may be smaller than in the first embodiment, so that the time required for connection between the terminals on the power transmitting coil unit 30 side and the terminals on the control device 20 side during construction can be shortened.

[0039] The first power transmitting coil unit 30-1 and the third power transmitting coil unit 30-3 may be connected in series and connected to a first common terminal 35A-1. The second power transmitting coil unit 30-2 and the fourth power transmitting coil unit 30-4 may be connected in series and connected to a second common terminal 35A-2. In the case of this embodiment, the number of cables 15 and connection terminals 35 may be further reduced compared to the case of the second embodiment, so that the time required for connection between the terminals on the power transmitting coil unit 30 side and the terminals on the control device 20 side during construction can be further reduced.

[0040] <Third embodiment> In this embodiment, a power supply system having a different configuration from that of the first embodiment will be described. Specifically, a power supply system including a sheet including a connection terminal on the lower side of a lower housing will be described.

[0041] Fig. 6 is a schematic cross-sectional view of the power supply system 10 B. As shown in Fig. 6, the power supply system 10 B includes a control device 20, a plurality of power transmitting coil units 30, and a housing 40, as well as a sheet body 70.

[0042] The sheet body 70 is provided below the lower housing 41. The sheet body 70 may have a connection portion 72 (also referred to as a conductive portion). The connection portion 72 is provided corresponding to each of the power transmitting coil units 30. This makes it easy to position the power transmitting coil unit 30 even when the power transmitting coil unit 30 is not arranged in the lower housing 41. In addition, in this embodiment, the cable 15 arranged in the ground 52 and the wire end portion 37 connected to the power transmitting coil unit 30 can be connected via the connection portion 72. The connection portion 72 has a function as a connection terminal (connector). Therefore, the cable 15 and the wire end portion 37 can be easily connected. Therefore, the installation work of the power transmitting coil unit 30 can be completed in a shorter time.

[0043] <Fourth embodiment> In this embodiment, a power supply system different from that in the first embodiment will be described. Specifically, a power supply system having a guide portion on the top surface portion 431C of the upper housing 43 will be described.

[0044] FIG. 7A is a top view of the upper housing 43C, and FIG. 7B is a side view of the protrusion. As shown in FIG. 7A, in this embodiment, a plurality of protrusions 431Ca are provided on the upper surface 431C of the upper housing 43C at intervals in the running direction (first direction D1) of the vehicle 60 in correspondence with the location where the power transmitting coil unit 30 is arranged. The driver of the vehicle 60 drives the vehicle 60 along the road 50 using the protrusions 431Ca as a guide. Specifically, the driver recognizes vibrations caused by the vehicle 60 passing over the protrusions 431Ca, and controls, for example, the speed or the running position of the vehicle 60. The vehicle 60 passes over the power transmitting coil unit 30 arranged inside the road 50. At this time, the driver controls the position of the vehicle 60 so that vibrations are caused by the protrusions 431Ca, so that the power transmitting coil 31 provided in the vehicle 60 can be made to face the position of the power receiving coil 61, thereby improving the efficiency of power supply to the vehicle 60. In the above, the plurality of protruding portions 431Ca can be used as guide portions for guiding the vehicle 60 to the location where the power transmitting coil is disposed.

[0045] Furthermore, the top surface 431C of the upper housing 43A may be exposed to the surface of the road 50. By exposing the top surface 431C of the upper housing 43A to the surface of the road 50, the distance to the power receiving coil 61 can be further shortened. In this case, the top surface 431C has a plurality of convex portions 431Ca, so that the vehicle 60 is prevented from slipping when passing over the top surface 431C.

[0046] Moreover, as shown in FIG. 7C, the convex portion 431Ca may have a cross-sectional shape in which the short side portion 431Ca1 tapers. This makes it possible to more effectively suppress slipping. Moreover, it is preferable that the long side portion 431Ca2 of the convex portion 431Ca extends in a direction (second direction D2) perpendicular to the traveling direction (first direction D1) of the vehicle 60 in order to facilitate the flow of rainwater to the side of the road 50. Moreover, as shown in FIG. 7C, the convex portion 431Ca may have a shape that narrows toward the side of the road 50 (sidewalk 55). This makes it possible to more efficiently flow rainwater to the side of the road 50.

[0047] 8A and 8B are cross-sectional views of the upper housing 43C. As shown in FIG. 8A, the upper surface 431C of the upper housing 43C may have an incline that slopes from the center of the road 50 toward both sides (sidewalks 55). Also, as shown in FIG. 8B, the upper surface 431C of the upper housing 43C may have an incline that slopes uniformly from one side (sidewalk 55) of the road 50 to the other side. This allows rainwater to flow efficiently to the sides of the road 50.

[0048] In this embodiment, when the upper surface portion 431C is not exposed, a paving material such as an asphalt mixture may be paved on the upper housing 43C. In this case, the upper surface portion 431C may constitute a part of the surface of the road 50.

[0049] In addition, in the present embodiment, an example in which the upper surface portion 431C has the convex portion 431Ca has been shown, but the upper surface portion 431C may have a concave portion, or a sign colored like a white line or a display device like digital signage may be provided on the upper surface portion 431C. Either of these can be used as a guide portion for guiding the vehicle 60 to the location where the power transmitting coil is arranged.

[0050] In the present embodiment, the protrusions are provided along the second direction D2 perpendicular to the first direction D1, but the present invention is not limited thereto. FIG. 9 is a top view of the upper housing 43C. As shown in FIG. 9, the protrusions 431Ca may be provided along the first direction D1 (the running direction of the vehicle 60) toward the stop line 48 arranged perpendicular to the running direction of the road 50, or along a direction inclined toward the inside of the upper housing 43C from the first direction. This allows the driver to drive along the road 50 using the protrusions 431Ca as a guide, thereby allowing the vehicle 60 to pass over the power transmitting coil unit 30. This allows the power transmitting coil 31 and the power receiving coil 61 to be arranged opposite to each other while suppressing the amount of misalignment between them, thereby improving the efficiency of power supply to the vehicle 60.

[0051] <Fifth embodiment> In this embodiment, a power supply system different from that in the first embodiment will be described. Specifically, a power supply system having a support provided between an upper housing and a lower housing 41 will be described.

[0052] FIG. 10A is a cross-sectional view of the housing 40D. FIG. 10B is a plan view of the housing 40D. As shown in FIG. 10A, in this embodiment, the housing 40D includes a support 47 in addition to the lower housing 41 and the upper housing 43. In this example, the support 47 is disposed between adjacent power transmission coil units 30. The support 47 is sandwiched between the upper housing 43 and the lower housing 41. The support 47 has a function of supporting the upper housing 43 and the lower housing 41. The support may be made of the same material as the upper housing 43. By having the support 47, the rigidity of the housing 40 can be increased.

[0053] FIG. 11A is a cross section of the support 47 seen from the upper housing 43 side. FIG. 11B is a schematic diagram of the support 47 seen from the side. FIG. 11C and FIG. 11D are a cross section of the housing 40E and a detailed view thereof. As shown in FIG. 11A and FIG. 11B, the support 47 may have a tubular (cylindrical) shape when seen from the lower housing 41 or the upper housing 43 side. Also, as shown in FIG. 11B, the support 47 may have an outlet hole 47a through which cables can be inserted in a part of the longitudinal direction (height direction). Also, as shown in FIG. 11C, the support 47 may be provided adjacent to the power transmission coil unit 30. When the support 47 is disposed near the wire end 37 of the power transmission coil unit 30, the wire end 37 connected to the connection terminal 35 of the power transmission coil unit 30 is routed through the support 47 via the hole 45a and led out to the outside of the housing 40. This increases the rigidity of the housing 40C and simplifies the routing of the wire ends 37. Therefore, by using this embodiment, positioning can be easily and simply performed, and the installation work of the power transmitting coil unit 30 can be completed in a short time.

[0054] In the present embodiment, the support 47 is provided locally, for example, between adjacent power transmission coil units 30, but the present invention is not limited to this. The support 47 may have a hexagonal cylindrical shape in the housing 40 as shown in FIG. 11E, and a plurality of supports 47 may be provided adjacent to each other in a honeycomb shape. This can further increase the rigidity of the housing 40. The support 47 may have a cylindrical shape that is not only a hexagonal cylindrical shape, but also a polygonal cylindrical shape such as a square or octagonal shape.

[0055] In addition, in the present embodiment, an example having a tubular (cylindrical) shape when viewed from the lower housing 41 or the upper housing 43 side has been shown, but the present invention is not limited thereto. FIG. 12A is a schematic diagram of the support 47 when viewed from the side. FIG. 12B is a cross-sectional view when viewed from the top. FIG. 12C is a cross-sectional schematic view of the housing 40E. As shown in FIGS. 12A to 12C, the support 47 may be provided separately on the upper housing 43 side and the lower housing 41 side. In this case, the support 47 may have a cylindrical shape and a hole 45a through which cables can be inserted in a part of the height direction. This makes it easier to route the wire end 37 connected to the power transmission coil unit 30. In this case, the support 47 is not limited to a cylindrical shape, and may be a polygonal prism such as a hexagonal prism as shown in FIG. 12D.

[0056] Sixth Embodiment In this embodiment, a power supply system different from that in the first embodiment will be described. Specifically, a power supply system having a drainage groove in a lower housing 41 will be described.

[0057] Fig. 13 is a schematic diagram of the lower housing 41F according to the present embodiment. As shown in Fig. 13, the lower housing 41F includes a groove Fm and a through hole 41Fk. The groove Fm is formed so as to divide the surface of the lower housing 41F on which the multiple power transmitting coil units 30 are installed into the respective regions on which the power transmitting coil units 30 are installed. The through hole 41Fk is provided in a part of the lower housing 41F in communication with the groove 41Fm. As a result, when water infiltrates into the inside of the housing, the water on the surface side of the lower housing 41 on which the power transmitting coil 31 is installed can be drained to the opposite side of the surface of the lower housing 41 on which the power transmitting coil 31 is installed by circulating through the groove Fm and the through hole Fk.

[0058] Seventh embodiment In this embodiment, a power supply system different from that in the first embodiment will be described. Specifically, a power supply system having a sensor will be described.

[0059] Fig. 14 is a schematic cross-sectional view of a power supply system 10G. As shown in Fig. 14, the power supply system 10G includes a control device 20 and a sensor 80. The sensor 80 may be disposed in a part of a walkway 55, may be disposed in the power transmitting coil unit 30, or may be disposed inside the housing 40. For example, when the sensor detects that a vehicle 60 has entered a predetermined area, the control device 20 may cause a current to flow through the power transmitting coil 31. The control device 20 may also have a power transmitting switch that opens and closes the output to the power transmitting coil 31.

[0060] Eighth embodiment In this embodiment, a power supply system different from that in the first embodiment will be described. Specifically, a wireless power supply unit having a connecting portion for connecting housings will be described.

[0061] 15A is an enlarged cross-sectional view of an end portion of the lower housing 41J. The lower housing 41J has a connecting portion 41Ja at an end portion in the running direction (first direction D1) of the vehicle 60. The lower housing 41J can be connected to another lower housing 41J adjacent in the running direction of the vehicle by a fastening member 410 via the connecting portion 41Ja. The connecting portion 41a has a plurality of connecting holes 41Jah penetrating in the thickness direction. The lower housing 41 is connected to the other lower housing 41 by the connecting portion 41Ja provided at the end in the running direction of the vehicle. The end of the lower housing 41 may be connected to the end of the other lower housing 41 by abutting against it.

[0062] 15B and 15C are cross-sectional views of the end of the lower housing 41. FIG. 15D and 15E are plan views of the end of the lower housing 41J. The lower housing 41J may be connected to another lower housing 41J via a gap member 46. In this case, the gap member 46J connects the front connecting portion 41Ja in the traveling direction of the vehicle in one lower housing 41J to the rear connecting portion 41a in the traveling direction of the vehicle in the other lower housing 41 by a fastening member 410. As shown in FIG. 15C, the gap member 46 has a stepped shape corresponding to the connecting portion 41Ja of the lower housing 41J, and has a connecting hole 46h corresponding to the connecting hole 41Jah of the connecting portion 41Ja of the lower housing 41J. The gap member 46 has a stepped shape at one end side connected to one lower housing 41J and at the other end side connected to the other lower housing 41J.

[0063] The connecting portion 41Ja on one end side of the gap member 46 and the connecting portion 41Ja on the other end side may be parallel to each other as shown in Fig. 15D, or may have a predetermined angle as shown in Fig. 15E. When the one end side and the other end side of the gap member 46 have a predetermined angle as shown in Fig. 15E, the other lower housing 41J connected by the gap member 46 has a predetermined angle with respect to the one lower housing 41J. This allows the lower housing 41J to be installed at a predetermined position even on a curved road.

[0064] (Modification) Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention. For example, those in which a person skilled in the art appropriately adds, deletes, or modifies the design of the above-mentioned embodiments, or adds, omits, or modifies the conditions of processing, are also included in the scope of the present invention as long as they include the gist of the present invention.

[0065] The upper housing 43 may have a material different from that of the lower housing 41. The upper housing 43 desirably includes a moisture-permeable material to prevent water from remaining on the road 50. On the other hand, the lower housing 41 may have a moisture-absorbent material to prevent moisture from remaining near the power transmission coil unit 30. As the moisture-absorbent material, for example, nylon resin can be used.

[0066] In the first embodiment of the present invention, an example in which four power transmitting coil units are arranged in the lower housing 41 has been described, but the present invention is not limited to this. For example, the lower housing 41 may have two power transmitting coil units arranged along the running direction of the two-wheeled vehicle so as to be compatible with a two-wheeled vehicle. Furthermore, the lower housing 41 may have, for example, eight power transmitting coil units arranged so as to be compatible with a large truck. In this case, a total of eight power transmitting coil units may be arranged, four along the running direction of the vehicle and two each along the directions perpendicular to the running direction of the vehicle.

[0067] In the first embodiment of the present invention, an example has been shown in which the top surface portion 431 of the upper housing 43 has the same shape as the bottom surface portion 411 of the lower housing 41 when viewed from above, but the present invention is not limited to this. The shape of the surface of the top surface portion 431 of the upper housing 43 may be larger than the bottom surface portion 411 of the lower housing 41 when viewed from above. This makes it possible to prevent rainwater from directly entering the inside of the housing 40.

[0068] In the first embodiment of the present invention, an example has been shown in which upper housing 43 has side surface portion 433, but the present invention is not limited to this. Lower housing 41 may have a side surface portion instead of upper housing 43. In this case, by making the surface shape of top surface portion 431 of upper housing 43 larger than the surface of bottom surface portion 411 of lower housing 41, upper housing 43 can be used as a lid and rainwater can be prevented from directly penetrating into the interior of housing 40.

[0069] In the first embodiment of the present invention, the upper housing 43 is formed from a synthetic resin material, but from the viewpoint of improving strength, it may have reinforcing fibers in addition to the synthetic resin material. In this case, the reinforcing fibers of the upper housing 43 may be any fibers other than those that block magnetic fields and electric fields when power is supplied wirelessly between the power transmitting coil 31 and the power receiving coil. For example, the upper housing 43 may be formed from FRP (Fiber Reinforced Plastics). When the upper housing 43 is formed from FRP, the reinforcing fibers may be, for example, glass fibers, carbon fibers, or aramid fibers.

[0070] In the first embodiment of the present invention, an example in which the cable 15 is connected from the lower side of the lower housing 41 has been described, but the present invention is not limited to this. Fig. 16 is a cross-sectional view of a power supply system 10K. As shown in Fig. 16, for example, a connection terminal 35 for connecting the cable 15 may be provided on a side surface. In this case, the side surface may be provided on either the lower housing 41 or the upper housing 43. This can reduce the amount of soil excavation in the road area, and the installation work of the power transmission coil unit 30 can be completed in a shorter time.

[0071] The lower housing 41 may be flexible as long as it can position the power transmitting coil unit. The lower housing 41 may be, for example, a sheet that can be rolled up into a roll.

[0072] According to one embodiment of the present invention, there is provided a wireless power supply unit 100 for a vehicle that wirelessly supplies power to a vehicle, the wireless power supply unit 100 including a plurality of power transmission coils and a lower housing that is installed inside a road and includes the plurality of power transmission coils, the plurality of power transmission coils being arranged along at least one of the vehicle running direction and the direction perpendicular to the running direction on a plane of the lower housing that is parallel to the road. Therefore, the positioning of the plurality of power transmission coils 31 can be easily and simply performed compared to a case where the power transmission coil units 30 are arranged in the ground. In addition, the wireless power supply unit 100 for a vehicle according to one embodiment of the present invention can support the unit with a larger area than the case where the power transmission coil unit 30 is a single unit, so that the depth and inclination of the coil in the ground can be suppressed from changing. In addition, the wireless power supply unit 100 for a vehicle according to one embodiment of the present invention is heavier than the power transmission coil unit 30 alone, so that the response can be reduced even when subjected to vibration from the outside, and improved durability can be expected. Furthermore, the vehicle wireless power supply unit 100 according to one embodiment of the present invention allows the coil to be buried in an accurate position regardless of the skill of the worker who installs it.

[0073] In the vehicle wireless power supply unit 100, the multiple power transmitting coils 31 may be arranged along a direction perpendicular to the traveling direction of the vehicle on the road. This makes it easier and simpler to position the multiple power transmitting coils 31 than when the power transmitting coil units 30 are arranged underground along a direction perpendicular to the traveling direction of the vehicle 60 on the road 50.

[0074] In the vehicle wireless power supply unit 100, the lower housing 41 may have a drainage groove 41Fm on the surface on which the power transmitting coil 31 is disposed. This allows water on the surface side of the lower housing 41 on which the power transmitting coil 31 is disposed to flow through the groove Fm and be drained.

[0075] In the vehicle wireless power supply unit 100, the lower housing 41 has through holes 41Fk penetrating from one side to the other side of the surface of the lower housing 41 on which the multiple power transmitting coils 31 are arranged, and the through holes 41Fk may be provided to communicate with the grooves 41Fm. This allows water on the surface side of the lower housing 41 on which the power transmitting coils 31 are arranged to flow through the through holes 41Fk and be drained to the opposite side of the surface of the lower housing 41 on which the power transmitting coils 31 are arranged.

[0076] In the vehicle wireless power supply unit 100, the lower housing 41 may have coupling parts 41Ja for coupling to other lower housings 41 at the front and rear ends in the traveling direction of the vehicle 60. This allows the lower housing 41 to be easily positioned since the installation position is specified by the coupling parts 41Ja provided at the ends in the traveling direction of the vehicle and the other lower housings 41. In addition, since the lower housing 41 is coupled to the other lower housings 41 by the coupling parts 41Ja provided at the ends in the traveling direction of the vehicle 60, the force caused by the traveling of the vehicle 60 transmitted via the road 50 can be dispersed.

[0077] The vehicle wireless power supply unit 100 may have an upper housing 43 that is provided on the lower housing 41, and that withstands a load from above and prevents water from entering the inside. This allows the housing 40 to withstand a force transmitted through the road 50 and prevents water from entering the inside of the housing 40.

[0078] The wireless power supply unit 100 for a vehicle may have a support 47 that transfers a load from the upper housing 43 to the lower housing 41. This allows the housing 40 to further withstand a load from above.

[0079] In the vehicle wireless power supply unit 100, the support 47 has a cylindrical shape capable of accommodating cables, one end in the axial direction of the cylindrical shape contacts the upper housing 43 and the other end contacts the lower housing 41, and may have an outlet hole 47a for the cables at a position between the upper housing 43 and the lower housing 41. In this way, the support 47 transmits the load from the upper housing to the lower housing, and the wires accommodated in the cylindrical shape can be taken out from the outlet hole 47a, simplifying the routing of the wires inside the housing 40.

[0080] The upper surface 431 of the upper housing 43 of the wireless power supply unit 100 for vehicles is paved as the road 50, and the upper surface 411 may form part of the surface of the road 50. This eliminates the need to pave the upper surface 431 of the housing 40 after the wireless power supply unit 100 for vehicles is buried in the road 50, thereby shortening the construction period.

[0081] The vehicle wireless power supply unit 100 may have a guide unit that guides the vehicle 60 on the upper surface 431 of the upper housing 43. This enables the vehicle wireless power supply unit 100 to guide the vehicle 60 to a predetermined position on the upper surface 431 of the upper housing 43 by the guide unit.

[0082] In the vehicle wireless power supply unit 100, the guide section has a convex cross-sectional shape and is rectangular in a plan view, and the leading end of the rectangular guide section in the vehicle traveling direction may be disposed closer to the center in the direction perpendicular to the vehicle traveling direction than the rear end of the rectangular guide section in the vehicle traveling direction. This allows the vehicle wireless power supply unit 100 to guide the vehicle 60 passing the guide section to a predetermined position by generating vibrations through the wheels of the vehicle 60 to allow the driver to recognize the traveling position.

[0083] In the wireless power feeding unit 100 for a vehicle, the multiple power transmitting coils 31 may be connected in parallel. This allows power to be fed to the multiple power transmitting coils 31 of the wireless power feeding unit 100 for a vehicle using a smaller number of cables 15.

[0084] According to one embodiment of the present invention, the wireless power feeding system for a vehicle includes the above-mentioned wireless power feeding unit 100 for a vehicle, a control device 20 that supplies power to the power transmitting coil 31, a cable 15 that supplies power from the control device 20 to the wireless power feeding unit 100 for a vehicle, and a sensor 80 that detects an intrusion of a vehicle into a predetermined area, and the control device 20 controls whether or not to supply power to the power transmitting coil 31 based on an output from the sensor 80. In this way, in the wireless power feeding system for a vehicle, when the sensor 80 detects a vehicle intruding into the predetermined area, the control device 20 supplies power to the multiple power transmitting coils 31, and when the sensor 80 does not detect a vehicle, the control device 20 controls not to supply power to the multiple power transmitting coils 31, thereby making it possible to reduce waste of power. [Explanation of symbols]

[0085] 10···Power supply system, 15···Cable, 20···Control device, 25···Connection terminal, 30···Power transmission coil unit, 31···Power transmission coil, 33···Resonant capacitor, 35···Connection terminal, 35A-1···First common terminal, 35A-2···Second common terminal, 37···Wire end, 39···Case, 40···Housing, 41···Lower housing, 41Fm···Groove, 41Fk···Through hole, 43···Upper housing, 45·· Filling, 45a, hole, 47, support, 50, road, 55, sidewalk, 60, vehicle, 61, receiving coil, 63, battery, 70, sheet body, 72, connection part, 80, sensor, 100, wireless power supply unit for vehicle, 411, bottom part, 411a, wiring hole, 431, top part, 431Ca, convex part, 431Ca1, short part, 431Ca2, long part, 433, side part

Claims

1. A wireless power supply unit for a vehicle that wirelessly supplies power to a vehicle, A plurality of transmitting coils; a lower housing that is installed inside a road and includes the plurality of power transmission coils; the plurality of power transmission coils are arranged along at least one of a vehicle travel direction and a direction perpendicular to the vehicle travel direction on a plane of the lower housing that is parallel to a road, the lower housing has a drainage groove on a surface on which the power transmitting coil is disposed. Wireless power supply unit for vehicles.

2. the lower housing has a through hole passing through from one side to the other side of a surface of the lower housing on which the plurality of power transmitting coils are arranged, The wireless power supply unit for a vehicle according to claim 1 , wherein the through hole is provided so as to communicate with the groove.

3. A wireless power supply unit for a vehicle that wirelessly supplies power to a vehicle, A plurality of transmitting coils; a lower housing that is installed inside a road and includes the plurality of power transmission coils; the plurality of power transmission coils are arranged along at least one of a vehicle travel direction and a direction perpendicular to the vehicle travel direction on a plane of the lower housing that is parallel to a road, The lower housing has connecting portions at front and rear ends in the traveling direction of the vehicle for connecting to other lower housings. Wireless power supply unit for vehicles.

4. A wireless power supply unit for a vehicle that wirelessly supplies power to a vehicle, A plurality of transmitting coils; A lower housing is installed inside a road and includes the plurality of power transmission coils; an upper housing provided on the lower housing, the upper housing being resistant to a load from above and preventing water from entering the inside; a support body that transmits a load from the upper housing to the lower housing, the plurality of power transmission coils are arranged along at least one of a vehicle travel direction and a direction perpendicular to the vehicle travel direction on a plane of the lower housing that is parallel to a road; Wireless power supply unit for vehicles.

5. The support has a tubular shape capable of accommodating cables, 5. The wireless power supply unit for a vehicle according to claim 4, wherein one end of the cylindrical shape in the axial direction is in contact with the upper housing and the other end is in contact with the lower housing, and a hole for passing cables is provided between the upper housing and the lower housing.

6. The upper surface of the upper housing is paved as a road, The wireless power supply unit for a vehicle according to claim 5 , wherein the upper surface forms a part of the surface of the road.

7. The wireless power supply unit for a vehicle according to claim 6 , further comprising a guide portion for guiding the vehicle on an upper surface of the upper housing.

8. The guide portion has a convex cross-sectional shape and a rectangular shape in a plan view, 8. The vehicle wireless power supply unit according to claim 7, wherein a front end of the rectangular guide portion in the vehicle travel direction is positioned closer to a center in a direction perpendicular to the vehicle travel direction than a rear end of the rectangular guide portion in the vehicle travel direction.

9. A wireless power supply unit for a vehicle, the wireless power supply unit including a plurality of power transmission coils and configured to wirelessly supply power to a vehicle; A control device that supplies power to the power transmitting coil; A cable for supplying power from the control device to the road vehicle wireless power supply unit; A sensor for detecting an intrusion of a vehicle into a predetermined area, the vehicle wireless power supply unit includes the plurality of power transmitting coils; and a lower housing that is installed inside a road and includes the plurality of power transmitting coils; the plurality of power transmission coils are arranged along at least one of a vehicle travel direction and a direction perpendicular to the vehicle travel direction on a plane of the lower housing that is parallel to a road, The control device controls whether or not to supply power to the power transmitting coil based on an output from the sensor. Wireless power supply system for vehicles.

Images