JP7373789B2 - Wireless power supply system, power transmission device, and power receiving device - Google Patents

Description

The present invention relates to a wireless power feeding system, a power transmitting device, and a power receiving device.

2. Description of the Related Art Conventionally, wireless power supply technology is known in which a power transmission device installed on a road surface or the like wirelessly supplies power to a power reception device installed in a vehicle. For example, Patent Document 1 discloses a vehicle that can receive power from a power transmission device provided on a road surface by providing a power receiving device on the lower side of the vehicle.

Japanese Patent Application Publication No. 2018-068077

However, with conventional wireless power transfer technology, when there is a distance between a power transmitting device installed on a road surface or the like and a power receiving device installed on a mobile object running on the road surface, the power transmitting device and the power receiving device If an obstacle such as a small animal or metal gets into the space between the two, there is a risk that eddy currents will be generated around the obstacle and the power supply efficiency will be reduced. In addition, there was a risk that small animals or metal that got between the power transmitting device and the power receiving device would be heated and ignite. Therefore, there is a need to further improve the usefulness of wireless power supply technology that wirelessly supplies power to mobile bodies.

An object of the present invention, made in view of the above circumstances, is to provide a wireless power supply system, a power transmission device, and a power reception device that can improve the usefulness of wireless power supply.

The wireless power supply system according to the present invention includes:
A power transmission device installed on a road, which includes a power transmission coil that transmits power wirelessly, and when installed on the road, at least a part of the power transmission coil is connected to the road in a cross section in the width direction of the road. a power transmission device located above a road surface in a vertical direction with respect to the road surface, and configured such that a coil surface of the power transmission coil is substantially perpendicular to the road surface;
A power reception device installed on a mobile body, comprising a power reception coil that receives power wirelessly, such that in a cross section in the width direction of the mobile body, a coil surface of the power reception coil meets the road surface of a wheel of the mobile body. a power receiving device configured to be substantially perpendicular to a ground plane;
including.
According to the wireless power feeding system according to the present invention, it is possible to reduce the possibility that an obstacle will enter the space between the power transmitting coil and the power receiving coil, and it is possible to improve the power feeding efficiency in wireless power feeding. Therefore, according to the wireless power supply system according to the present invention, the usefulness of the wireless power supply technique for wirelessly supplying power to a mobile object is improved.

In the wireless power supply system according to the present invention, it is preferable that a plurality of the power transmission devices are installed in a line along the extending direction of the road.
According to this configuration, the wireless power supply system can transmit power to a power receiving device of a moving body traveling on a road.

In the wireless power supply system according to the present invention, it is preferable that at least one driving lane is provided on the road, and that at least one pair of the power transmission devices is installed in the driving lane in the width direction of the driving lane. .
According to this configuration, the wireless power supply system can transmit power to each wheel when a plurality of wheels are installed side by side in the width direction of the mobile body.

In the wireless power supply system according to the present invention, it is preferable that the power transmitting device transmits power wirelessly when determining that the power receiving device is present in a position where it can receive the power from the power transmitting device.
According to this configuration, the wireless power feeding system can reduce power consumption caused by the power transmitting device wirelessly transmitting power when the power receiving device is not in a position where it can receive power.

In the wireless power feeding system according to the present invention, it is preferable that at least a portion of the power receiving coil is housed in the wheel.
According to this configuration, the wireless power feeding system can further reduce the possibility that an obstacle will enter the space between the power transmitting coil and the power receiving coil.

In the wireless power supply system according to the present invention, it is preferable that the wheel is a tire-wheel assembly including a tire and a wheel.
According to this configuration, in the wireless power feeding system, the inner space of the wheel is separated from the outside of the wheel by the tire and the wheel, thereby reducing the possibility that an obstacle will enter the space between the power transmitting coil and the power receiving coil. Can be done.

The power transmission device according to the present invention includes a power transmission coil that transmits power wirelessly, and when installed on a road, at least a part of the power transmission coil is lower than the road surface in a cross section in the width direction of the road. , is located vertically above the road surface, and is configured such that a coil surface of the power transmission coil is substantially perpendicular to the road surface.
According to the power transmission device according to the present invention, electric power can be transmitted wirelessly while a moving body including the power receiving device is traveling on a road. Therefore, according to the power transmission device according to the present invention, the usefulness of the wireless power supply technique for wirelessly supplying power to a mobile object is improved.

The power receiving device according to the present invention includes a power receiving coil that receives power wirelessly, and when installed on a moving body, the coil surface of the power receiving coil is aligned with the wheel of the moving body in a cross section in the width direction of the moving body. It is configured to be approximately perpendicular to the ground contact surface with the road surface.
According to the power receiving device according to the present invention, power can be wirelessly received from a power transmission device installed on a road while a moving object is traveling on the road. This allows the power to drive the mobile object to be received from outside the mobile object, making it possible to reduce the size and weight of the storage battery installed in the mobile object, which in turn makes it possible to improve the fuel efficiency of the mobile object. . Therefore, according to the power receiving device according to the present invention, the usefulness of the wireless power supply technique for wirelessly supplying power to a mobile object is improved.

According to the present invention, it is possible to provide a wireless power supply system, a power transmission device, and a power reception device that can improve the usefulness of wireless power supply technology that wirelessly supplies power to a mobile object.

1 is a schematic diagram schematically showing a wireless power supply system according to an embodiment of the present invention using a cross section in the width direction of a wheel. 1 is a schematic diagram schematically showing a tire/wheel assembly as an example of a wheel in a wireless power supply system according to an embodiment of the present invention using a cross section in the width direction of the wheel. FIG. 1 is a functional block diagram schematically showing a configuration example of a power transmission device according to an embodiment of the present invention. FIG. 2 is a schematic diagram schematically showing a coil surface and its inclination of a power transmission coil included in a power transmission device according to an embodiment of the present invention using a cross section in the width direction of a road. FIG. 1 is a functional block diagram schematically showing a configuration example of a power receiving device according to an embodiment of the present invention. FIG. 2 is a schematic diagram schematically showing a coil surface and an inclination of a power receiving coil included in a power receiving device according to an embodiment of the present invention using a cross section in the width direction of a road. 1 is a schematic diagram showing an example of installing a power transmission device on a road in a wireless power supply system according to an embodiment of the present invention. FIG. 2 is a schematic diagram schematically showing a modification of the wireless power supply system according to an embodiment of the present invention using a cross section in the width direction of a wheel. FIG. 7 is a schematic diagram schematically showing another modification of the wireless power supply system according to an embodiment of the present invention using a cross section in the width direction of a wheel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A wireless power feeding system, a power transmitting device, and a power receiving device according to an embodiment of the present invention will be described below with reference to the drawings. Common parts and parts in each figure are given the same reference numerals. In this specification, the width direction of the wheel refers to a direction parallel to the rotation axis of the wheel. The radial direction of the wheel refers to a direction perpendicular to the rotational axis of the wheel. The extending direction of a road or a driving lane refers to the direction in which a road or a driving lane extends. The width direction of a road or a driving lane refers to a direction perpendicular to the direction in which it extends. The width direction of the moving body refers to a direction perpendicular to the direction in which the moving body travels.

(Configuration of wireless power supply system)
The configuration of a wireless power supply system 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a schematic diagram schematically showing a wireless power supply system 1 according to an embodiment of the present invention using a widthwise cross section of a wheel 6 of a moving body 5. Wireless power feeding system 1 includes a power transmitting device 2 and a power receiving device 3. The power transmission device 2 is installed on a road 4. The power receiving device 3 is installed on the mobile body 5. As a result, in the wireless power supply system 1, when the mobile object 5 travels on the road 4 in the extending direction of the road 4, power is transmitted wirelessly from the power transmitting device 2 to the power receiving device 3.

The power transmission device 2 includes a power transmission coil 21 . The power transmission device 2 wirelessly transmits power using the power transmission coil 21 . The power transmission device 2 is installed on the road 4 such that at least a portion of the power transmission coil 21 is located above the road surface of the road 4 in the vertical direction with respect to the road surface.

Specifically, the power transmission device 2 includes an exposed portion 2A and a buried portion 2B. The exposed portion 2A protrudes upward in the vertical direction with respect to the road surface of the road 4 in a cross section of the road 4 in the width direction when the power transmission device 2 is installed on the road 4. The buried portion 2B is buried below the road surface of the road 4 with the power transmission device 2 installed on the road 4. In this embodiment, in order to stably install the power transmission device 2 on the road 4, the power transmission device 2 includes the buried portion 2B, but the buried portion 2B may be omitted. When the power transmission device 2 does not include the buried portion 2B, the power transmission device 2 can be easily installed on the road surface of the road 4. At least a portion of the power transmission coil 21 is housed in the exposed portion 2A of the power transmission device 2, so that it is installed on the road 4 so as to be located above the road surface of the road 4 in the vertical direction with respect to the road surface. There is. In FIG. 1, the power transmission coil 21 is shown schematically for the sake of simplicity of explanation.

The power receiving device 3 includes a power receiving coil 31 . The power receiving coil 31 receives power wirelessly transmitted from the power transmitting coil 21 of the power transmitting device 2 . The power receiving device 3 is installed on the mobile body 5. In the present embodiment, in the power receiving device 3, at least a portion of the power receiving coil 31 is housed in the wheel 6 of the moving body 5. In this embodiment, the power receiving device 3 is attached to the wheels 6 of the moving body 5 so that at least a portion of the power receiving coil 31 is accommodated in the wheels 6 of the moving body 5. However, the power receiving device 3 may be attached to the main body of the moving body 5 such that at least a portion of the power receiving coil 31 is accommodated in the wheels 6 of the moving body 5. In FIG. 1, the power receiving coil 31 is shown schematically for simplicity of explanation.

The road 4 has a road surface used for traffic by moving objects 5. In this specification, the "road surface" is the surface of the road 4 on which the moving body 5 travels with the wheels 6. In this embodiment, the road 4 is, for example, a roadway. However, the road 4 is not limited to a roadway, and may include a sidewalk, a farm road, a forest road, an airstrip, a parking lot, a vacant lot, an open space, and the like. The traffic of the moving body 5 includes running, stopping, and parking of the moving body 5.

At least one driving lane 41 may be provided on the surface of the road 4. The driving lane 41 is an area of the road surface defined as an area in which the moving body 5 travels. The road 4 may be provided with a plurality of travel lanes 41 depending on the number of moving objects 5 that can run in parallel. Partition lines such as white lines may be drawn on the road surface of the road 4 to indicate the driving lanes 41.

In this embodiment, the road surface of the road 4 is paved with, for example, asphalt. However, the road surface of the road 4 is not limited to asphalt, and may be made of concrete, stone, brick, soil, gravel, or the like.

The moving body 5 travels on the road surface 4 using wheels 6. In the present embodiment, the mobile object 5 is a vehicle whose power source includes a motor, such as an electric vehicle or a hybrid vehicle. Automobiles include passenger cars, trucks, buses, motorcycles, etc. However, the mobile object 5 is not limited to automobiles, and includes agricultural vehicles such as tractors, construction vehicles such as dump trucks, airplanes, helicopters, motorized bicycles, electric bicycles, electric wheelchairs, and the like.

The wheels 6 are used to move the moving body 5. The wheels 6 are attached to the moving body 5 and have a ground contact surface that contacts the road surface of the road 4 . In this embodiment, the wheel 6 is a tire/wheel assembly in which a tire 61 is mounted on a wheel 62, but the present invention is not limited to this. In this specification, the "contact surface" of the wheel 6 refers to the contact surface of the tire 61 when the wheel 6 is a tire-wheel assembly, that is, the tire 61 is mounted on an applicable rim, filled with a specified internal pressure, and Refers to the surface of the tire 61 that comes into contact with the road surface under a load.

In this specification, "applicable rim" refers to an industrial standard that is valid in the region where pneumatic tires are produced and used, such as the JATMA YEAR BOOK of JATMA (Japan Automobile Tire Association) in Japan, and ETRTO (in Europe). It is described in the STANDARDS MANUAL of The European Tire and Rim Technical Organization, and in the YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States. Standard rims (ETRTO In STANDARDS MANUAL, it refers to Measuring Rim, and in TRA's YEAR BOOK, it refers to Design Rim), but in the case of a size not listed in these industrial standards, it refers to a rim with a width corresponding to the bead width of a pneumatic tire. "Applicable rim" includes not only current sizes but also sizes that may be included in the aforementioned industrial standards in the future. Examples of "sizes to be described in the future" include sizes described as "FUTURE DEVELOPMENTS" in the 2013 edition of ETRTO.

In this specification, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in the applicable size and ply rating, as described in industrial standards such as the aforementioned JATMA YEAR BOOK, In the case of sizes not listed in the above-mentioned industrial standards, this refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is installed. In addition, in this specification, "maximum load" refers to the load corresponding to the maximum load capacity of tires of applicable sizes listed in the above-mentioned industrial standards, or in the case of tires of sizes not listed in the above-mentioned industrial standards. means the load corresponding to the maximum load capacity specified for each vehicle equipped with the tire.

FIG. 2 is a schematic diagram illustrating a tire/wheel assembly as an example of the wheel 6 in the wireless power supply system 1 according to an embodiment of the present invention using a widthwise cross section of the wheel 6. ing.

As shown in FIG. 2, the tire 61 includes a pair of bead portions 611, a pair of sidewall portions 612, and a tread portion 613. The bead portion 611 is configured such that when the tire 61 is mounted on the rim portion 621 of the wheel 62, the radially inner side and the widthwise outer side of the bead portion 611 are in contact with the rim portion 621. The sidewall portion 612 extends between the tread portion 613 and the bead portion 611. The sidewall portion 612 is located on the outer side of the wheel 6 in the radial direction than the bead portion 611 . The tread portion 613 is located radially outward of the wheel 6 than the sidewall portion 612 and includes the ground contact surface of the tire 61.

The tire 61 is made of rubber such as natural rubber and synthetic rubber, and may include parts made of metal such as steel, such as a carcass, belt, and bead wire. For example, at least some of the parts such as the carcass, belt and bead wire may be made of non-magnetic material. As a result, the tire 61 maintains the strength of the tire 61 and the presence of metal between the power transmitting device 2 and the power receiving device 3 allows the magnetic field generated by the power transmitting coil 21 to reach the power receiving coil 31. Attenuation can be reduced, and as a result, the power feeding efficiency of wireless power feeding from the power transmitting device 2 to the power receiving device 3 can be improved. However, at least some of the parts such as the carcass, belt, and bead wire may not be made of non-magnetic material.

Non-magnetic materials can include paramagnetic and diamagnetic materials with low magnetic permeability. As the non-magnetic material, resin materials can be used, including, for example, thermoplastic resins such as polyester and nylon, thermosetting resins such as vinyl ester resins and unsaturated polyester resins, and other synthetic resins. The resin material can further contain fibers such as glass, carbon, graphite, aramid, polyethylene, and ceramic as reinforcing fibers. As the nonmagnetic material, any nonmetallic material can be used, including not only resin but also rubber, glass, carbon, graphite, aramid, polyethylene, ceramic, and the like. Further, as the non-magnetic material, a metal material including a paramagnetic material such as aluminum or a diamagnetic material such as copper can be used.

The wheel 62 includes a cylindrical rim portion 621 on which the tire 61 is mounted, a hub portion 622 provided on the radially inner side of the rim portion 621 and fixed to the shaft 52 of the moving body 5, and a hub portion 622 supported by the hub portion 622. It has a disk part 623 which is fixed and supports and fixes the rim part 621.

Wheel 62 may be formed of metal such as steel, but is not limited thereto. At least a portion of the rim portion 621, hub portion 622, and disk portion 623 of the wheel 62 may be formed of the non-magnetic material described above. As a result, while maintaining the strength of the wheel 62, the presence of metal such as steel between the power transmitting device 2 and the power receiving device 3 allows the magnetic field generated by the power transmitting coil 21 to be attenuated before reaching the power receiving coil 31. This makes it possible to reduce the amount of power being transferred from the power transmitting device 2 to the power receiving device 3, and improve the power feeding efficiency of wireless power feeding from the power transmitting device 2 to the power receiving device 3. However, at least a portion of the rim portion 621, hub portion 622, and disk portion 623 of the wheel 62 may not be made of a non-magnetic material.

In FIG. 2, the power receiving device 3 is attached to a hub portion 622 of the wheel 62. In this state, at least a portion of the power receiving coil 31 is accommodated in the wheel 6. "Accommodated in the wheel" means that it is arranged radially inside the outer peripheral surface of the wheel and inside both ends of the wheel in the width direction. In this embodiment, the entire power receiving coil 31 is housed in the wheel 6. However, the power receiving coil 31 does not need to be housed in the wheel 6 (see FIG. 8).

The power receiving device 3 is installed at a portion of the wheel 6 that does not rotate with rotation of the wheel 6, such as a cover of the hub portion 622 of the wheel 62. As a result, the power receiving device 3 can easily supply electric power stably wirelessly from outside the wheel 6 because the relative position of the power receiving coil 31 inside the wheel 6 does not change according to the rotation of the tire 61. become.

(Configuration of power transmission device)
Next, the configuration of the power transmission device 2 included in the wireless power supply system 1 according to an embodiment of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 shows a functional block diagram schematically showing a configuration example of the power transmission device 2 according to an embodiment of the present invention. As shown in FIG. 3, the power transmission device 2 includes a power conversion section 22, a power storage section 23, a detection section 24, a communication section 25, a storage section 26, and a control section 27 in addition to the power transmission coil 21. The power transmission coil 21, the power conversion unit 22, the power storage unit 23, the detection unit 24, the communication unit 25, the storage unit 26, and the control unit 27 are connected to each other by wire or wirelessly via a network such as a LAN (Local Area Network). Connected for communication.

Power transmission coil 21 generates an alternating current magnetic field. In this embodiment, the power transmitting coil 21 has an annular shape as a whole. In this specification, the plane surrounded by the annular power transmission coil 21 is also referred to as the coil surface S1 of the power transmission coil 21. In other words, the power transmission coil 21 is wound in the in-plane direction of the coil surface S1 so as to form the coil surface S1. The power transmission coil 21 can generate an alternating current magnetic field in a direction perpendicular to the power transmission coil 21, that is, in a direction in which a perpendicular to the coil surface S1 extends.

FIG. 4 shows a schematic diagram that schematically shows the coil surface S1 and its inclination of the power transmission coil 21 included in the power transmission device 2 according to an embodiment of the present invention using a cross section in the width direction of a road. . As shown in FIG. 4, the power transmission device 2 is configured such that the coil surface S1 of the power transmission coil 21 is substantially perpendicular to the road surface in a cross section in the width direction of the road 4 when installed on the road 4. . More specifically, when the power transmission device 2 is installed on the road 4, the power transmission coil 21 is installed through the support member 211 so that the coil surface S1 is substantially perpendicular to the road surface in the cross section in the width direction of the road 4. is supported and fixed to the casing of the power transmission device 2. At least a portion of the support member 211 and the housing of the power transmission device 2, particularly at least a portion of the exposed portion 2A of the power transmission device 2, may be formed of the non-magnetic material described above. This makes it difficult for the magnetic field generated by the power transmission coil 21 to attenuate when passing through the support member 211 and the casing of the power transmission device 2 .

In this specification, for example, when surface A is "substantially perpendicular" to surface B, preferably surface A is perpendicular to surface B. However, it is not necessary to be completely perpendicular, and the surface A may be inclined by approximately ±5 degrees with respect to the perpendicular to the surface B.

Referring again to FIG. 3, power conversion section 22 is connected to power transmission coil 21. The power converter 22 includes, for example, an AC/DC converter, an inverter, and the like. The power conversion unit 22 converts the power transmitted from the power source P or the power storage unit 23 located outside the power transmission device 2 and transmits the converted power to the power transmission coil 21 .

Power storage unit 23 is connected to power conversion unit 22 . The power storage unit 23 includes, for example, chargeable and dischargeable storage batteries such as a lead acid battery, a nickel metal hydride battery, a lithium ion battery, and a sodium sulfur battery. Power storage unit 23 is not limited to a storage battery, and may include a capacitor or the like. The power storage unit 23 stores power transmitted from the power source P via the power conversion unit 22, or transmits power to the power transmission coil 21.

The detection unit 24 includes sensors such as an infrared sensor, an image sensor, a motion sensor, and a pressure sensor. The detection unit 24 detects that the power receiving device 3 is located at a position where it can receive power from the power transmitting device 2 .

Communication unit 25 includes one or more communication modules. The communication module is, for example, a wired LAN communication module, a wireless LAN communication module, a CAN (Controller Area Network) communication module, or the like. The communication unit 25 realizes communication with an external computer or the like via a network such as the Internet.

The storage unit 26 is, for example, a semiconductor memory, a magnetic memory, an optical memory, or the like. The storage unit 26 functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit 26 stores arbitrary information used for the operation of the power transmission device 2. For example, the storage unit 26 stores system programs, application programs, embedded software, and the like.

Control unit 27 includes one or more processors. The processor may be, for example, a general-purpose processor such as a CPU (Central Processing Unit), or a dedicated processor specialized for specific processing. The control unit 27 is not limited to a processor, and may include one or more dedicated circuits. The dedicated circuit may be, for example, an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). The control unit 27 controls the power transmission coil 21, the power conversion unit 22, the power storage unit 23, the detection unit 24, the communication unit 25, and the storage unit 26 described above to realize the functions of the power transmission device 2.

The control unit 27 can determine whether the power receiving device 3 is present at a position where it can receive power from the power transmitting device 2. Specifically, the control unit 27 determines that the power receiving device 3 is present at a position where it can receive power from the power transmitting device 2 by detecting the power receiving device 3 using the detecting unit 24 . The control unit 27 may indirectly determine that the power receiving device 3 exists in a position where it can receive power from the power transmitting device 2 by detecting the moving object 5 or the wheels 6 by the detecting unit 24 . Alternatively, the control unit 27 may obtain information indicating that the power receiving device 3 is present at a position where it can receive power from the power transmitting device 2 from the power receiving device 3 or an external computer via the communication unit 25.

When the control unit 27 determines that the power receiving device 3 is present in a position where it can receive power from the power transmitting device 2, it can transmit power wirelessly. Specifically, the control unit 27 controls at least one of the power transmission coil 21, the power conversion unit 22, and the power storage unit 23 to apply an alternating current magnetic field in the direction in which the perpendicular to the coil surface S1 of the power transmission coil 21 extends. can be generated.

(Configuration of power receiving device)
Next, the configuration of the power receiving device 3 included in the wireless power feeding system 1 according to an embodiment of the present invention will be described with reference to FIGS. 5 and 6.

FIG. 5 shows a functional block diagram schematically showing a configuration example of the power receiving device 3 according to an embodiment of the present invention. As shown in FIG. 5, in addition to the power receiving coil 31, the power receiving device 3 includes a power conversion section 32, a power storage section 33, a detection section 34, a communication section 35, a storage section 36, and a control section 37. The power receiving coil 31, the power conversion unit 32, the power storage unit 33, the detection unit 34, the communication unit 35, the storage unit 36, and the control unit 37 are communicably connected to each other by wire or wirelessly via a network such as CAN. ing.

The power receiving coil 31 receives power wirelessly. In this embodiment, the power receiving coil 31 has an annular shape as a whole. In this specification, the plane surrounded by the annular power receiving coil 31 is also referred to as a coil surface S2 of the power receiving coil 31. In other words, the power receiving coil 31 is wound in the in-plane direction of the coil surface S2 so as to form the coil surface S2. In the power receiving coil 31, an electromotive force is generated by electromagnetic induction due to changes in the alternating current magnetic field generated by the power transmitting coil 21 and the like and passing through the coil surface S2, and current flows through the power receiving coil 31.

FIG. 6 shows a schematic diagram schematically showing the coil surface S2 and the inclination thereof of the power receiving coil 31 included in the power receiving device 3 according to an embodiment of the present invention. As shown in FIG. 6, the power receiving device 3 has a coil surface S2 of the power receiving coil 31 in a cross section in the width direction of the moving body 5, with at least a portion of the power receiving coil 31 accommodated in the wheels 6 of the moving body 5. is configured to be substantially perpendicular to the ground contact surface of the wheels 6 with the road surface. More specifically, in a state in which at least a portion of the power receiving coil 31 is accommodated in the wheels 6 of the mobile body 5, the coil surface S2 of the power receiving coil 31 is It is fixed to the casing of the power receiving device 3 via a support member 311 so as to be substantially perpendicular to the ground contact surface of the wheels 6 with the road surface. As a result, while the moving body 5 is traveling on the road 4, the coil surface S2 of the power receiving coil 31 faces the coil surface S1 of the power transmitting coil 21, and wireless power is transferred from the power transmitting coil 21 to the power receiving coil 31 by electromagnetic induction. It will be done. At least a portion of the support member 311 and the housing of the power receiving device 3 may be formed of the above-mentioned nonmagnetic material. This makes it difficult for the magnetic field generated by the power transmitting coil 21 to attenuate when passing through the support member 311 and the housing of the power receiving device 3 .

Here, in this specification, for example, when (at least a part of) surface A "opposes" surface B, it means within a region extending in the perpendicular direction of surface B within the range in which surface B extends (in other words, , within a columnar region whose cross section is surface B), which overlaps (at least a portion of) surface A.

Referring again to FIG. 5, power converter 32 is connected to power receiving coil 31. The power converter 32 includes, for example, an AC/DC converter, an inverter, and the like. The power conversion unit 32 transmits the power generated in the power receiving coil 31 to the vehicle-mounted device 51 mounted on the mobile body 5.

The on-vehicle device 51 is, for example, a motor. In such a case, the on-vehicle device 51, which is a motor, consumes the power transmitted from the power receiving device 3 to drive the wheels 6. More specifically, in this embodiment, the in-vehicle device 51 is an in-wheel motor mounted on the wheel 6. However, the on-vehicle device 51 may be an on-board motor that is mounted on the main body of the moving body 5 and drives the wheels 6 by rotating the shaft 52 of the moving body 5.

The in-vehicle device 51 is not limited to a motor, and may include any electronic device installed in the moving object 5, such as a storage battery, a communication device, a car navigation system, a media player, and an in-vehicle sensor.

Power storage unit 33 is connected to power conversion unit 32 . The power storage unit 33 includes, for example, chargeable and dischargeable batteries such as a lead acid battery, a nickel metal hydride battery, a lithium ion battery, and a sodium sulfur battery. Power storage unit 33 is not limited to a storage battery, and may include a capacitor. When the power storage unit 33 includes a capacitor, it can be charged and discharged in a shorter time than a storage battery or the like, which is advantageous in situations where high responsiveness is required. Power storage unit 33 stores power transmitted from power receiving coil 31 via power conversion unit 32, or transmits power to vehicle-mounted device 51.

The detection unit 34 includes sensors such as a voltage sensor and a current sensor. The detection unit 34 detects the power that the power receiving coil 31 receives wirelessly.

Communication unit 35 includes one or more communication modules. The communication module is, for example, a wired LAN communication module, a wireless LAN communication module, a CAN communication module, or the like. The communication unit 35 communicates with an external computer including the power transmission device 2, or an in-vehicle device 51 of the mobile body 5, etc. via a network such as the Internet.

The storage unit 36 is, for example, a semiconductor memory, a magnetic memory, an optical memory, or the like. The storage unit 36 functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit 36 stores arbitrary information used for the operation of the power receiving device 3. For example, the storage unit 36 stores system programs, application programs, embedded software, and the like.

Control unit 37 includes one or more processors. The processor may be, for example, a general-purpose processor such as a CPU, or a dedicated processor specialized for specific processing. The control unit 37 is not limited to a processor, and may include one or more dedicated circuits. The dedicated circuit may be, for example, an FPGA or an ASIC. The control unit 37 controls the power reception coil 31, the power conversion unit 32, the power storage unit 33, the detection unit 34, the communication unit 35, and the storage unit 36 described above to realize the functions of the power reception device 3.

The control unit 37 can measure the power that the power receiving device 3 is receiving wirelessly. Specifically, the control unit 37 measures the intensity of the power wirelessly received by the power receiving coil 31 based on the information detected by the detection unit 34 . The intensity of electric power may be expressed by arbitrary numerical information such as electric power, electric energy, voltage, current, magnetic flux, or magnetic flux density.

The control unit 37 can transmit the power wirelessly received by the power receiving device 3 to the vehicle-mounted device 51 mounted on the mobile body 5. Specifically, the control unit 37 can transmit the power generated in the power receiving coil 31 to the vehicle-mounted device 51. Alternatively, the control unit 37 may store the power generated in the power receiving coil 31 in the power storage unit 33 and then transmit the power from the power storage unit 33 to the vehicle-mounted device 51.

(Example of installing power transmission equipment on a road)
An example of installing the power transmission device 2 on the road 4 in the wireless power supply system 1 will be described below with reference to FIGS. 1 and 7. FIG. 7 is a schematic diagram showing an example of installing a power transmission device on a road in a wireless power supply system according to an embodiment of the present invention. FIG. 7 shows a perspective view of the wireless power supply system 1 shown in FIG. 1.

In this embodiment, the wireless power supply system 1 includes a plurality of power transmission devices 2. A plurality of power transmission devices 2 are installed in a line along the extending direction of the road 4. Specifically, as shown in FIG. 7, a plurality of power transmission devices 2 are installed side by side in the extending direction of the road 4 at a predetermined interval D on the outside in the width direction of the travel lane 41 of the road 4. . The predetermined interval D may be arbitrarily determined.

Furthermore, at least one pair of power transmission devices 2 is installed in the driving lane 41 of the road 4 in the width direction of the driving lane 41. Specifically, the power transmission coils 21 of each of the pair of power transmission devices 2 are installed so as to face each other across the driving lane 41 from the outside in the width direction of the driving lane 41 of the road 4 . Thereby, electric power can be wirelessly transmitted from the outside in the width direction of the mobile body 5 to the power receiving coil 31 of the power receiving device 3 housed in the wheel 6 of the mobile body 5 traveling on the road 4. Therefore, it is possible to reduce the possibility that the wheels 6 run above the power transmission device 2 while the moving body 5 is traveling on the road 4 and the power transmission device 2 is damaged by the load from the wheels 6.

Below, a modification of the wireless power supply system 1 will be described with reference to FIGS. 8 and 9. FIG. 8 is a schematic diagram schematically showing a modified example of the wireless power supply system according to an embodiment of the present invention using a cross section in the width direction of a wheel. FIG. 9 is a schematic diagram schematically showing another modification of the wireless power supply system according to an embodiment of the present invention using a widthwise cross section of a wheel.

As shown in FIG. 8, the power receiving device 3 may be installed outside the wheel 6 in the width direction. The position on the outside in the width direction of the wheel 6 may be, for example, a position adjacent to the wheel 62. By installing the power receiving device 3 at a position where the distance between the power transmitting device 2 and the power receiving device 3 is shortened when the mobile object 5 travels on the road 4, power feeding efficiency can be further improved. . In FIG. 8 , the entire power receiving device 3 is arranged outside the wheel 6 in the width direction, but only a part of the power receiving device 3 including the power receiving coil 31 may be arranged outside the wheel 6 in the width direction.

The power receiving coil 31 of the power receiving device 3 is not limited to the above-mentioned position, and may be installed at any position on the wheel 6. The power receiving coil 31 of the power receiving device 3 may be installed, for example, on the inner circumferential surface of the rim portion 621 of the wheel 62 or on the outer circumferential surface of the rim portion 621. Furthermore, the power receiving coil 31 of the power receiving device 3 may be installed on the inner circumferential surface of the tread portion 613 of the tire 61, or may be installed inside the tread portion 613 of the tire 61. Furthermore, the power receiving device 3 is not limited to the wheels 6, and may be installed on the outer wall surface of the side surface of the main body of the moving body 5.

In the modified example of the wireless power supply system 1 shown in FIG. They are placed side by side. Further, the power receiving device 3 is installed on the outer peripheral surface of the rim portion 621 of the wheel 62. Thereby, electric power can be wirelessly transmitted from the inner side in the width direction of the mobile body 5 to the power receiving device 3 housed in the wheel 6 of the mobile body 5 traveling on the travel lane 41 of the road 4. Therefore, the space between the power transmitting coil 21 and the power receiving coil 31 is surrounded by the road surface of the road 4, the main body of the moving body 5, and the wheels 6, and it is difficult for obstacles to enter the space.

As described above, the wireless power feeding system 1 according to an embodiment of the present invention includes the power transmitting device 2 and the power receiving device 3. The power transmission device 2 is a power transmission device 2 installed on a road 4 and includes a power transmission coil 21 that transmits power wirelessly. is located above the road surface of the road 4 in a direction perpendicular to the road surface, and the coil surface of the power transmission coil 21 is configured to be substantially perpendicular to the road surface. The power receiving device 3 is a power receiving device 3 installed in a mobile body 5, and includes a power receiving coil 31 that receives power wirelessly.In the cross section in the width direction of the mobile body 5, the coil surface of the power receiving coil 31 is aligned with the mobile body 5. It is configured to be substantially perpendicular to the ground contact surface of the wheels 6 of No. 5 and the road surface. According to the wireless power feeding system 1 having such a configuration, it is possible to reduce the possibility that an obstacle will enter the space between the power transmitting coil 21 and the power receiving coil 31. Therefore, the wireless power supply system 1 can improve power supply efficiency in wireless power supply. Therefore, according to the wireless power supply system 1 according to the embodiment of the present invention, the usefulness of the wireless power supply technique for wirelessly supplying power to the mobile object 5 is improved.

In the wireless power supply system 1 according to the embodiment of the present invention, it is preferable that a plurality of power transmission devices 2 are installed in a line along the extending direction of the road 4. According to this configuration, the wireless power supply system 1 can wirelessly transmit power from the plurality of power transmission devices 2 to the power receiving device 3 housed in the wheel 6 of the moving object 5 traveling on the road 4. .

In the wireless power supply system 1 according to the embodiment of the present invention, at least one driving lane 41 is provided on the road 4, and at least one pair of power transmission devices 2 is installed in the driving lane 41 in the width direction of the driving lane 41. It is preferable that the According to this configuration, when a plurality of wheels 6 are installed in line in the width direction of the moving body 5, such as in a four-wheeled vehicle, the wireless power supply system 1 can provide power to each wheel 6, respectively. Electric power can be wirelessly transmitted from the power transmitting device 2 .

In the wireless power supply system 1 according to the embodiment of the present invention, the power transmission device 2 preferably transmits power wirelessly when it is determined that the power reception device 3 is present in a position where it can receive power from the power transmission device 2. . According to this configuration, the wireless power supply system 1 can reduce the power consumption of the power transmission device 2 by transmitting power wirelessly when the power transmission device 2 is not in a position where the power reception device 3 can receive power. can.

In the wireless power feeding system 1 according to the embodiment of the present invention, it is preferable that at least a portion of the power receiving coil 31 is housed in a wheel of the moving body 5. According to this configuration, in the wireless power supply system 1, the interior space of the wheel 6 is separated from the outside of the wheel 6 by the wheel 6, so that it is difficult for obstacles to approach the vicinity of the power receiving coil 31. Thereby, the wireless power feeding system 1 can further reduce the possibility that an obstacle will enter the space between the power transmitting coil 21 and the power receiving coil 31.

In the wireless power supply system 1 according to the embodiment of the present invention, the wheels 6 are preferably tire-wheel assemblies including tires 61 and wheels 62. According to this configuration, in the wireless power supply system 1, the inner space of the wheel 6 is divided from the outside of the wheel 6 by the tires 61 and the wheels 62, so that no obstacles exist in the space between the power transmitting coil 21 and the power receiving coil 31. It is possible to reduce the risk of intrusion.

A power transmission device 2 according to an embodiment of the present invention includes a power transmission coil 21 that transmits power wirelessly, and when installed on a road 4, at least a portion of the power transmission coil 21 is , is located above the road surface of the road 4 in the vertical direction with respect to the road surface, and is configured such that the coil surface of the power transmission coil 21 is substantially perpendicular to the road surface. According to this configuration, the power transmitting device 2 can wirelessly transmit power while the mobile body 5 including the power receiving device 3 is traveling on the road 4. Further, the power transmission device 2 reduces the possibility that the wheels 6 of the mobile object 5 run above the power transmission device 2 while the mobile object 5 is traveling on the road 4 and the power transmission device 2 is damaged by the load from the wheels 6. can be done. Therefore, according to the power transmission device 2 according to the embodiment of the present invention, the usefulness of the wireless power supply technique for wirelessly supplying power to the mobile body 5 is improved.

A power receiving device 3 according to an embodiment of the present invention includes a power receiving coil 31 that receives power wirelessly, and when installed on a moving body 5, the coil surface of the power receiving coil 31 is is configured to be substantially perpendicular to the contact surface of the wheels 6 of the moving body 5 with the road surface. According to this configuration, the power receiving device 3 can wirelessly receive power from the power transmitting device 2 installed on the road 4 while the moving object 5 is traveling on the road 4. As a result, the power receiving device 3 can receive power for driving the mobile body 5 from outside the mobile body 5, making it possible to reduce the size and weight of the storage battery installed in the mobile body 5. This makes it possible to improve the fuel efficiency of the body 5. Therefore, according to the power receiving device 3 according to the embodiment of the present invention, the usefulness of the wireless power supply technique for wirelessly supplying power to the mobile body 5 is improved.

Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art will be able to easily make various changes and modifications based on the present invention. It should therefore be noted that these variations and modifications are included within the scope of the present invention. For example, the configurations, functions, etc. included in each embodiment or each example can be rearranged so as not to be logically contradictory. Furthermore, the configurations or functions included in each embodiment can be used in combination with other embodiments or other examples, and multiple configurations or functions can be combined into one, divided, or combined into one. It is possible to omit the part.

For example, in the embodiment described above, all or part of the functions or processes described as the functions or processes of the control unit 27 of the power transmitting device 2 or the control unit 37 of the power receiving device 3 may be performed on a general-purpose computer such as a smartphone or a personal computer. It may also be realized as a computer function or process. Specifically, a program that describes the processing contents for realizing each function of the control unit 27 of the power transmission device 2 or the control unit 37 of the power reception device 3 according to the present embodiment is stored in the memory of the computer, and is executed by the processor of the computer. The program can be read and executed. Therefore, the invention according to this embodiment can also be realized as a program executable by a processor. For example, a control device (ECU: Electronic Control Unit) of the mobile body 5 may be configured to function as the control section 37 of the power receiving device 3.

Furthermore, in the embodiment described above, the power transmitting device 2 and the power receiving device 3 are configured such that the control unit 37 of the power receiving device 3 executes some or all of the operations and processes executed by the control unit 27 of the power transmitting device 2. It's okay. For example, when the mobile object 5 travels on the road 4 on which the power transmitting device 2 is installed, the control unit 37 of the power receiving device 3 may control the power transmitting device 2 to cause the power transmitting device 2 to wirelessly transmit power. good.

For example, in the embodiment described above, the tire 61 was described as being filled with air, but this is not the case. For example, the tire 61 can be filled with a gas such as nitrogen. Further, for example, instead of or in addition to gas, the tire 61 can be filled with any fluid including liquid, gel material, powder, or the like.

1: Wireless power supply system, 2: Power transmission device, 2A: Exposed part, 2B: Buried part, 21: Power transmission coil, 211: Support member, 22: Power conversion unit, 23: Power storage unit, 24: Detection unit, 25: Communication 26: Storage unit, 27: Control unit, 3: Power receiving device, 31: Power receiving coil, 311: Support member, 32: Power conversion unit, 33: Power storage unit, 34: Detection unit, 35: Communication unit, 36: Storage unit, 37: Control unit, 4: Road, 41: Driving lane, 5: Moving object, 51: On-vehicle device, 52: Shaft, 6: Wheel, 61: Tire, 611: Bead unit, 612: Sidewall unit, 613: Tread section, 62: Wheel, 621: Rim section, 622: Hub section, 623: Disc section, P: Power supply, S1, S2: Coil surface

Claims (5)

A power transmission device installed on a road, which includes a power transmission coil that transmits power wirelessly, and when installed on the road, at least a part of the power transmission coil is connected to the road in a cross section in the width direction of the road. a power transmission device located above a road surface in a vertical direction with respect to the road surface, and configured such that a coil surface of the power transmission coil is substantially perpendicular to the road surface;
A power reception device installed on a mobile body, comprising a power reception coil that receives power wirelessly, such that in a cross section in the width direction of the mobile body, a coil surface of the power reception coil meets the road surface of a wheel of the mobile body. a power receiving device configured to be substantially perpendicular to a ground plane;
including;
The road is provided with at least one driving lane, and the pair of power transmission devices are installed in the driving lane in the width direction of the driving lane,
Each of the coil surfaces of the power transmission coils of the pair of power transmission devices is configured to be capable of wirelessly transmitting power in mutually different directions outward in the width direction of the travel lane. The wireless power supply system according to claim 1, wherein a plurality of the power transmission devices are installed in a line along the extending direction of the road. The wireless power feeding system according to claim 1 , wherein the power transmitting device wirelessly transmits power when the power receiving device is determined to be in a position where the power receiving device can receive the power from the power transmitting device. The wireless power feeding system according to any one of claims 1 to 3 , wherein at least a portion of the power receiving coil is housed in the wheel. 5. The wireless power supply system according to claim 4 , wherein the wheel is a tire-wheel assembly including a tire and a wheel.

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