JP7273644B2 - WIRELESS POWER RECEIVING SYSTEM, CONTROL METHOD OF WIRELESS POWER RECEIVING SYSTEM, AND TIRE AND WHEEL ASSEMBLY - Google Patents

Description

The present invention relates to a wireless power receiving system, a control method for a wireless power receiving system, and a tire/wheel assembly.

2. Description of the Related Art Conventionally, there has been known a wireless power supply technology in which a power transmission device installed on a road, a parking lot, or the like wirelessly supplies power to a power reception device mounted on a vehicle. For example, Patent Literature 1 discloses a vehicle that can be charged by a power transmission device provided on a road surface by equipping a vehicle wheel or tire with a power receiving device.

Japanese Patent Application Laid-Open No. 2004-242380

Conventionally, in the wireless power supply technology for power receiving devices used in vehicles, when the distance between the power receiving device installed in the vehicle and the power transmitting device installed on the road vertically downward from the power receiving device is large, the power receiving efficiency was likely to decline.

SUMMARY OF THE INVENTION An object of the present invention, which has been made in view of such circumstances, is to provide a wireless power receiving system, a control method for the wireless power receiving system, and a tire/wheel assembly that improve power receiving efficiency in wireless power feeding.

A wireless power receiving system according to the present invention comprises a tire/wheel assembly comprising a tire and a wheel, and a power receiving device housed in the tire/wheel assembly and receiving power wirelessly supplied from outside the tire in the radial direction of the tire. a compressor connected to the tire so as to allow ventilation; a control device that controls the compressor to change the internal pressure of the tire;
wherein the control device determines whether or not the power receiving device is in a position capable of receiving power wirelessly, and determines whether the power receiving device is capable of wirelessly receiving power when the internal pressure of the tire is a first internal pressure. If it is determined to be at the position, the internal pressure of the tire is changed to a second internal pressure lower than the first internal pressure, and when the internal pressure of the tire is the second internal pressure, the power receiving device wirelessly receives power. If it is determined that it is not in the possible position, the internal pressure of the tire is changed to the first internal pressure.
According to the wireless power receiving system of the present invention, the power receiving device accommodated in the tire/wheel assembly can efficiently receive power wirelessly supplied from the power transmitting device installed on the road or the like. Power reception efficiency in power feeding is improved.

In the wireless power receiving system according to the present invention, it is preferable that the control device determines whether or not the power receiving device is in a position where power can be received wirelessly, based on information received from GPS satellites. According to such a configuration, it is possible to determine whether or not the power receiving device is at a position where power can be received wirelessly, based on highly versatile information that can be received from GPS satellites.

In the wireless power receiving system according to the present invention, the control device determines whether the power receiving device is at a position where power can be received wirelessly, based on information indicating the position of a power transmitting device that wirelessly supplies power to the power receiving device. is preferably determined. According to such a configuration, determination is made after specifying the position of the power transmission device, so it is possible to determine with higher accuracy whether or not the power reception device is at a position where power can be received wirelessly.

In the wireless power receiving system according to the present invention, the control device can determine whether or not the power receiving device is in a position where power can be received wirelessly, based on the intensity of power wirelessly supplied to the power receiving device. preferable. With such a configuration, determination is made based on the intensity of power actually received by the power receiving device, so whether or not the power receiving device is at a position where power can be received wirelessly can be determined with high accuracy.

In the wireless power receiving system according to the present invention, the tire includes a tread portion made of a non-magnetic material, the wheel includes a rim portion at least partially made of a non-magnetic material, and the power receiving device includes: It is preferable that the power receiving device is accommodated inside the rim portion of the wheel in the tire radial direction. According to this configuration, when the power transmission device is a device that generates a magnetic field, the magnetic field generated by the power transmission device reaches the power receiving device housed in the tire/wheel assembly from the tire radial direction outer side of the tire. Attenuation through the tread of the tire and the rim of the wheel can be reduced by .

In the wireless power receiving system according to the present invention, it is preferable that the wheel includes a slip ring for connecting the compressor to the tire in an air-permeable manner. When the tire rotates in the tire circumferential direction and the compressor is mounted at a position where it does not rotate, it is possible to prevent the ventilation path between the tire and the compressor from being twisted and damaged.

In the wireless power receiving system according to the present invention, it is preferable that the power receiving device receives power supplied by an electromagnetic induction method. According to such a configuration, wireless power supply can be performed with high transmission efficiency.

A control method for a wireless power receiving system according to the present invention includes the step of determining whether or not the power receiving device is in a position where power can be received wirelessly by the control device; when it is determined that the power receiving device is in a position where power can be received wirelessly when the internal pressure is equal to , changing the internal pressure of the tire to a second internal pressure lower than the first internal pressure; and changing the internal pressure of the tire to the first internal pressure when the internal pressure of the tire is the second internal pressure and the power receiving device is determined not to be in a position where power can be received wirelessly. .
According to the control method of the wireless power receiving system according to the present invention, the power receiving device accommodated in the tire/wheel assembly can efficiently receive power wirelessly supplied from the power transmitting device provided on the road or the like. This improves the efficiency of power reception in wireless power supply.

A tire-wheel assembly according to the present invention is a tire-wheel assembly comprising a tire and a wheel, wherein electric power is housed in the tire-wheel assembly and supplied wirelessly from the outside of the tire in the radial direction of the tire. A power receiving device for receiving power, a compressor connected to the tire so as to allow ventilation, and a control device for controlling the compressor to change the internal pressure of the tire, wherein the control device controls the power receiving device to wirelessly receive power. If it is determined that the power receiving device is in a position where wireless power reception is possible when the internal pressure of the tire is the first internal pressure, the internal pressure of the tire is reduced to the first internal pressure. is changed to a second internal pressure lower than the internal pressure of the tire, and when the internal pressure of the tire is the second internal pressure and it is determined that the power receiving device is not in a position where power can be received wirelessly, the internal pressure of the tire is changed to the Change to the first internal pressure.
According to the tire/wheel assembly of the present invention, the power receiving device accommodated in the tire/wheel assembly can efficiently receive power wirelessly supplied from a power transmitting device provided on a road or the like. , the power reception efficiency in wireless power supply is improved.

Advantageous Effects of Invention According to the present invention, it is possible to provide a wireless power receiving system, a control method for a wireless power receiving system, and a tire/wheel assembly that improve power receiving efficiency in wireless power feeding.

1 is a schematic diagram schematically showing a wireless power receiving system according to an embodiment of the present invention using a cross section in the tire width direction; FIG. 1 is a tire width direction cross-sectional view of an example of a tire in a wireless power receiving system according to an embodiment of the present invention. FIG. 1 is a wheel width direction cross-sectional view of an example of a wheel in a wireless power receiving system according to an embodiment of the present invention. FIG. 1 is a functional block diagram schematically showing an example configuration of a control device in a wireless power receiving system according to an embodiment of the present invention; FIG. FIG. 2 is a flow chart showing the flow of a control method for the wireless power receiving system according to one embodiment of the present invention; It is a schematic diagram which shows roughly the modification of the radio|wireless electric power receiving system which concerns on one Embodiment of this invention using a tire width direction cross section.

A wireless power receiving system, a control method for a wireless power receiving system, and a tire/wheel assembly according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals are given to the members/parts that are common in each figure.

(Configuration of wireless power receiving system)
FIG. 1 shows a schematic diagram schematically showing a wireless power receiving system 1 according to one embodiment of the present invention using a cross section in the tire width direction. The wireless power receiving system 1 includes a tire-wheel assembly 3 in which a tire 10 is mounted on a wheel 20, a power receiving device 30, a compressor 50, and a control device 60, which are provided in a vehicle 2 such as an automobile. The vehicle 2 is, for example, a vehicle driven by a user, but is not limited to this, and may be a vehicle in which complete or partial automatic operation is performed. The power receiving device 30 is attached, for example, to the hub 2A of the vehicle 2 and housed in the tire/wheel assembly 3 . The compressor 50 is air-permeably connected to the tire 10, more specifically, to the inner cavity of the tire 10, for example, by a rubber tube or the like. The control device 60 is communicably connected to the compressor 50 via an in-vehicle network such as CAN (Controller Area Network). The positions and numbers of the tires 10, the wheels 20, the power receiving device 30, the compressor 50, and the control device 60 included in the wireless power receiving system 1 are not limited to the example shown in FIG. can be arbitrarily determined.

The power transmission device 40 includes a power transmission coil (primary coil) 41 . The power transmission device 40 is installed on a road surface such as a road, or is buried so as to be positioned near the road surface. The power transmission coil 41 generates an alternating magnetic field based on the alternating current supplied from the power source. The power transmission coil 41 has a ring shape as a whole, and is arranged so that the axial direction of the ring is substantially perpendicular to the road surface so as to generate an AC magnetic field directed upwards from the road surface. However, in the drawing, the power transmission coil 41 is schematically illustrated. The power transmission coil 41 included in the power transmission device 40 is, for example, wound around a core such as a ferrite core, and configured in an annular shape as a whole. It can be any coil that can be generated. As a result, when the tire 10 passes over the power transmission device 40 while the vehicle 2 is running or the like, wireless power supply is performed from the power transmission device 40 to the power reception device 30 by an electromagnetic induction method or the like.

An operation example of a wireless power receiving system 1 according to an embodiment of the present invention will be described with reference to FIG. The control device 60 identifies the position of the vehicle 2, for example, based on information received from GPS (Global Positioning System) satellites, and determines whether or not the vehicle 2 is in a position where power can be supplied by wireless power supply. .

When the control device 60 determines that the vehicle 2 is in a position where it can be supplied with power by wireless power supply when the internal pressure of the tire 10 is the first internal pressure, it controls the compressor 50 to increase the internal pressure of the tire 10 . The internal pressure is changed to a second internal pressure that is lower than the first internal pressure. As a result, the outer diameter of the tire 10 is reduced and the distance between the power receiving device 30 and the power transmitting device 40 is shortened, so that the transmission efficiency of wireless power supply can be improved. Furthermore, by changing the internal pressure of the tire 10 to a second internal pressure that is lower than the first internal pressure, the ground contact area of the tire 10 is increased and the area to which power is supplied is widened.

On the other hand, when the internal pressure of the tire 10 is the second internal pressure and the control device 60 determines that the vehicle 2 is not in a position where power can be supplied by wireless power supply, the control device 60 controls the compressor 50 so that the tire 10 is changed to the first internal pressure. As a result, the rolling resistance coefficient (RRC) of the tire 10 is reduced, and the fuel efficiency of the tire 10 can be improved.

Next, each configuration of the wireless power receiving system 1 will be described in detail.

(Tire configuration)
An example configuration of a tire in the wireless power receiving system 1 according to one embodiment of the present invention will be described in detail.

Hereinafter, unless otherwise specified, the positional relationship, etc. of each element shall be measured under the standard condition in which the tire is mounted on the rim portion of the wheel, which is the applicable rim, filled with the specified internal pressure, and no load is applied. . In addition, when the tire is mounted on the rim portion of the wheel, which is the applicable rim, the tire is filled with the specified internal pressure, and the maximum load is applied, the width of the contact patch in contact with the road in the tire width direction is the contact width of the tire. The edge of the ground contact surface in the width direction of the tire is called the contact edge.

As used herein, the term "applicable rim" refers to an industrial standard effective in the region where pneumatic tires are produced and used, such as JATMA (Japan Automobile Tire Manufacturers Association) JATMA YEAR BOOK in Japan and ETRTO (Europe) in Europe. The European Tire and Rim Technical Organization's STANDARDS MANUAL, TRA's (The Tire and Rim Association, Inc.) YEAR BOOK in the United States, etc. Measuring Rim in STANDARDS MANUAL and Design Rim in TRA YEAR BOOK), but for sizes not listed in these industrial standards, it refers to a rim with a width corresponding to the bead width of a pneumatic tire. "Applicable rims" include current sizes as well as sizes that may be included in the aforementioned industry standards in the future. An example of a "size to be described in the future" may include sizes described as "FUTURE DEVELOPMENTS" in the 2013 edition of ETRTO.

As used herein, the term "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 the industrial standards such as the JATMA YEAR BOOK. In the case of sizes not listed in the aforementioned industrial standards, the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is mounted is used. In this specification, the "maximum load" refers to a load corresponding to the maximum load capacity of a tire of the applicable size described in the industrial standards described above, or in the case of a size not described in the industrial standards described above. means the load corresponding to the maximum load capacity specified for each vehicle on which the tire is mounted.

FIG. 2 shows a cross-sectional view in the tire width direction of the tire 10 of this embodiment cut along the tire width direction. As used herein, the tire width direction refers to a direction parallel to the rotation axis of the tire 10 . In FIG. 2, the tire width direction is indicated by an arrow W. As shown in FIG. Moreover, the tire radial direction refers to a direction perpendicular to the rotation axis of the tire 10 . In FIG. 2, the tire radial direction is indicated by an arrow R. As shown in FIG. In this embodiment, the tire 10 is described as being symmetrical with respect to the equatorial plane CL of the tire.

In this specification, the side closer to the rotational axis of the tire 10 along the tire radial direction is referred to as the "tire radial inner side", and the side farther from the rotational axis of the tire 10 along the tire radial direction is referred to as the "tire radial outer side". called. On the other hand, the side closer to the tire equatorial plane CL along the tire width direction is referred to as the "tire width direction inner side", and the side farther from the tire equatorial plane CL along the tire width direction is referred to as the "tire width direction outer side".

As shown in FIG. 2 , the tire 10 has a pair of bead portions 11 , a pair of sidewall portions 12 and a tread portion 13 . Sidewall portion 12 extends between tread portion 13 and bead portion 11 . The sidewall portion 12 is located outside the bead portion 11 in the tire radial direction. As used herein, the tread portion 13 may be the portion between the grounding edges described above.

The pair of bead portions 11 each have a bead core 11A for fixing the tire 10 to the rim portion 21 of the wheel 20 and a bead filler 11B for increasing the rigidity of the bead portions 11 . As shown in a partially enlarged view in FIG. 2, the bead core 11A includes a plurality of bead wires 11c whose peripheries are covered with rubber. The bead filler 11B is made of rubber or the like, and is positioned radially outward of the bead core 11A.

Tire 10 has a carcass 14 . The carcass 14 extends in a toroidal shape between the pair of bead cores 11A to form the frame of the tire. The end side of the carcass 14 is engaged with the bead core 11A. Specifically, the carcass 14 has a carcass body portion 14A arranged between the bead cores 11A, and a carcass folded portion 14B folded around the bead cores 11A from the inner side in the tire width direction to the outer side in the tire width direction. ing. In this embodiment, the carcass 14 has a radial structure using carcass cords, but it is not limited to this, and can have an arbitrary structure such as a bias structure. The carcass 14 can be composed of one or more (one in FIG. 2) carcass layers. As partially enlarged in FIG. 2, the carcass layer of the present embodiment includes one or more carcass cords 14c and a covering rubber 14r covering the carcass cords 14c.

A belt 15 and tread rubber for reinforcing the tread portion 13 are provided outside the carcass 14 in the tread portion 13 in the tire radial direction. The belt 15 can be configured by, for example, one or more (two in FIG. 2) belt layers 15a and 15b laminated in the tire radial direction. As partially enlarged in FIG. 2, each belt layer 15a, 15b includes one or more belt cords 15c and a covering rubber 15r covering the belt cords 15c.

The tire 10 has an inner liner 16 for retaining gas such as air in the inner cavity of the tire 10 . The inner liner 16 is arranged so as to cover the inner wall surface of the tire 10 .

When the power receiving device 30 is accommodated in the tire-wheel assembly 3, the members constituting the tread portion 13, such as the belt 15 and the carcass 14, which are positioned radially outward of the power receiving device 30, are made of a non-magnetic material. may be formed. As a result, the presence of metal such as steel between the power receiving device 30 and the power transmitting device 40 while maintaining the strength of the tire 10 and the wheel 20 allows the magnetic field generated by the power transmitting device 40 to reach the power receiving device 30. It is possible to prevent the power from attenuating by the time the power reaches the power receiving device 30 , thereby improving power reception efficiency in wireless power feeding of the power receiving device 30 .

Non-magnetic materials include paramagnetic and diamagnetic materials with low magnetic permeability. As the non-magnetic material, for example, resin materials including plastic resins such as polyester and nylon, thermosetting resins such as vinyl ester resins and unsaturated polyester resins, and other synthetic resins can be used. The resin material can further contain fibers such as glass, carbon, graphite, aramid, polyethylene, and ceramics as reinforcing fibers. Non-magnetic materials are not limited to resins, and any non-metallic materials including rubber, glass, carbon, graphite, aramid, polyethylene, and ceramics can be used. Furthermore, metal materials including paramagnetic materials such as aluminum or diamagnetic materials such as copper can be used as non-magnetic materials.

When the power receiving device 30 is accommodated in the tire/wheel assembly 3, the members constituting the bead portion 11, the sidewall portion 12, and the like, which are located outside the power receiving device 30 in the tire width direction, are made of ferrite, etc. It may comprise a magnetic material with high magnetic permeability, eg a ferromagnetic material. As a result, the magnetic field reaching the power receiving device 30 from the power transmitting device 40 located outside the tire 10 in the tire radial direction is reduced to the magnetic field of the metal and other substances existing outside the bead portion 11 and the sidewall portion 12 in the tire width direction. Attenuation due to influence can be prevented, and the power receiving efficiency of the power receiving device 30 can be improved.

(Wheel configuration)
Next, an example configuration of the wheel in the wireless power receiving system 1 according to one embodiment of the present invention will be described in detail.

FIG. 3 shows a cross-sectional view in the wheel width direction of the wheel 20 of this embodiment cut along the wheel width direction. In this specification, the wheel width direction refers to a direction parallel to the rotation axis of the wheel 20 . In FIG. 3, the wheel width direction is indicated by an arrow W. As shown in FIG. Moreover, the wheel radial direction refers to a direction orthogonal to the rotation axis of the wheel 20 . In FIG. 3, the wheel radial direction is indicated by arrow R. As shown in FIG. When the tire 10 is mounted on the wheel 20, the wheel width direction is parallel to the tire width direction, and the wheel radial direction is parallel to the tire radial direction.

In this specification, the side closer to the rotation axis of the wheel 20 along the wheel radial direction is referred to as the "wheel radial inner side", and the side farther from the rotation axis of the wheel 20 along the wheel radial direction is referred to as the "wheel radial outer side". called. On the other hand, the side closer to the equatorial plane CL of the wheel along the wheel width direction is referred to as the "wheel width direction inner side", and the side farther from the wheel equatorial plane CL along the wheel width direction is referred to as the "wheel width direction outer side".

As shown in FIG. 3 , the wheel 20 has a cylindrical rim portion 21 and a disk portion 22 provided inside the rim portion 21 in the tire radial direction and supported and fixed to the hub 2A of the vehicle 2. there is

The rim portion 21 is provided with a pair of flanges 23, a pair of bead seats 24, and a well 25 from the outside in the wheel width direction. The bead portion 11 of the tire 10 is attached to the bead seat 24 . The flange 23 extends outward in the wheel radial direction and the wheel width direction from the bead seat 24 in order to support the bead portion 11 of the tire 10 from the side surface. The well 25 has a concave shape facing inward in the wheel radial direction between the pair of bead seats 24 in order to facilitate attachment and detachment of the tire. Therefore, the well 25 has an inclined surface that descends inward in the wheel radial direction from the boundary with the bead seat 24 to the bottom surface of the well 25 as it goes inward in the wheel width direction. Further, the bead seat 24 is provided with a pair of humps 26 on the inner side in the wheel width direction. The hump 26 projects outward in the wheel radial direction to prevent the bead of the tire from falling into the well 25 .

At least part of the rim portion 21 is made of, for example, the resin material described above, but is not limited to this, and can be made of any non-magnetic material. As a result, while maintaining the strength of the wheel 20, when the power receiving device 30 is accommodated inside the rim portion 21 of the wheel 20 in the wheel radial direction, that is, inside the tire radial direction, The magnetic field reaching the power receiving device 30 from the power transmitting device 40 located outside can be prevented from being attenuated by passing through the rim portion 21 , and thus the power receiving efficiency of the power receiving device 30 can be improved.

The rim portion 21 of the wheel 20 is further provided with a valve 27 for filling gas such as air into the inner cavity of the tire 10 when the tire 10 is mounted. The valve 27 can be made of, for example, the non-magnetic material described above. By configuring the valve 27 with a non-magnetic material, when the power receiving device 30 is accommodated inside the rim portion 21 of the wheel 20 in the wheel radial direction, the power transmitting device positioned outside the rim portion 21 in the wheel radial direction. The magnetic field reaching the power receiving device 30 from 40 can be prevented from being attenuated by the valve 27, and the power receiving efficiency of the power receiving device 30 can be improved.

However, the rim portion 21 does not have to be entirely made of non-magnetic material. For example, when the tire 10 is mounted, the inner portion in the tire width direction of the portion facing the tread portion 13 of the tire 10 is made of a non-magnetic material, and the outer portion in the tire width direction is made of a ferromagnetic material such as metal. It may be made of any material. As a result, the power receiving device 30 housed in the wheel 20 can improve the strength of the wheel 20 or reduce the manufacturing cost of the wheel 20 without reducing the power receiving efficiency of the wireless power supply on the ground surface of the tire 10. can.

The disc portion 22 is provided with an annular mounting portion 22A forming a radially inner end portion, and a plurality of spokes 22B extending outward in the wheel radial direction from the mounting portion 22A. The mounting portion 22A is a portion that is coupled and fixed to the hub 2A of the vehicle 2, and has a mounting hole penetrating in the wheel width direction for inserting a bolt or the like for fixing the hub 2A and the mounting portion 22A. . The wheel radially outer end of the spoke 22B is integrally joined to the wheel radially inner surface end of the rim portion 21 .

The disk portion 22 may comprise a magnetic material, such as a ferromagnetic material, having a high magnetic permeability, such as metal or ferrite. Since the disk portion 22 contains a magnetic material, when the power receiving device 30 is housed inside the rim portion 21 of the wheel 20 in the wheel radial direction, the power transmitting device 40 is positioned outside the rim portion 21 in the wheel radial direction. It is possible to prevent the magnetic field reaching the power receiving device 30 from being attenuated by the influence of the metal and other magnetic fields existing outside the disk portion 22 in the wheel width direction, thereby improving the power receiving efficiency of the power receiving device 30. can. On the other hand, the disk portion 22 can be made of the resin material described above. As a result, the weight of the wheel 20 can be reduced.

The disc portion 22 of the wheel 20 is provided with a wheel cover 28 that covers the outside of the spokes 22B in the wheel width direction. The wheel cover 28 may comprise a magnetic material, such as a metal or ferrite, having a high magnetic permeability, eg a ferromagnetic material. Since the wheel cover 28 contains a magnetic material, when the power receiving device 30 is accommodated inside the rim portion 21 of the wheel 20 in the wheel radial direction, the power transmitting device 40 is located outside the rim portion 21 in the wheel radial direction. It is possible to prevent the magnetic field reaching the power receiving device 30 from being attenuated by the influence of the metal and other magnetic fields existing outside the wheel cover 28 in the wheel width direction, thereby improving the power receiving efficiency of the power receiving device 30. can.

A slip ring 29 is provided on the wheel 20 . The slip ring 29 can be provided on the mounting portion 22A of the wheel 20, for example. The compressor 50 and the valve 27 provided in the vehicle 2 are connected via a slip ring 29 when they are connected with a rubber tube or the like so as to allow ventilation. As a result, when the tire 10 and the wheel 20 rotate in the tire circumferential direction, the valve 27 similarly rotates. etc. can be prevented from being twisted and damaged.

(Configuration of power receiving device)
Next, an example configuration of the power receiving device in the wireless power receiving system 1 according to one embodiment of the present invention will be described in detail.

The power receiving device 30 includes a power receiving coil (secondary coil) 31 . As shown in FIG. 1 , the power receiving device 30 is housed in the tire/wheel assembly 3 . The power receiving device 30 is attached to the hub 2A or the drive shaft 2B of the vehicle 2, for example, so that the power receiving device 30 can be attached to the tire of the rim portion 21 of the wheel 20 while the wheel 20 is attached to the hub 2A of the vehicle 2. Housed radially inward. The power receiving coil 31 is formed in an annular shape as a whole, and the axial direction of the ring is substantially perpendicular to the road surface so as to face the power transmitting coil 41 when the tire-wheel assembly 3 is positioned above the power transmitting device 40 . are arranged so that As a result, when the tire 10 is positioned on the road surface above the power transmission coil 41 , electromotive force is generated in the power reception coil 31 by electromagnetic induction based on the alternating magnetic field generated by the power transmission coil 41 , and current flows. The power receiving coil 31 included in the power receiving device 30 is, for example, wound around a core such as a ferrite core and configured in an annular shape as a whole. It can be any coil that can generate an electromotive force based on it.

The power receiving device 30 may further include a power conversion circuit, a power storage unit, a measurement unit, and a control unit. The power conversion circuit converts the power generated in the power receiving coil 31 into DC power, and supplies the DC power to a power storage unit or other in-vehicle devices provided in the vehicle 2 via a conductive wire or the like. The power storage unit stores power generated in the power receiving coil 31 . The power storage unit is, for example, a capacitor, but is not limited to this, and may be any power storage device such as a storage battery. When the power storage unit is a capacitor, it can be charged and discharged in a shorter time than a storage battery. Therefore, the power storage unit, which is a capacitor, is advantageous in situations where high responsiveness is required, such as storing power generated in the power receiving coil 31 when the vehicle 2 travels on the power transmission device 40 provided on the road. be. The measuring unit is, for example, a voltmeter or an ammeter, and can calculate the intensity of power wirelessly supplied from the outside to the power receiving device 30 by measuring voltage or current. In this specification, the power intensity refers to any numerical value representing the intensity of power wirelessly supplied to the power receiving device 30, such as power, power amount, voltage, current, magnetic flux amount, or magnetic flux density. The control unit may include one or more processors that provide processing for controlling each function of power receiving device 30 . The control unit can be a general-purpose processor such as a CPU (Central Processing Unit) that executes a program defining a control procedure, or a dedicated processor that specializes in processing each function. The control unit may include arbitrary means used to control the power receiving device 30, such as storage means for storing programs and the like, and communication means for wired or wireless communication with an external electronic device.

Although the power receiving device 30 is installed in the hub 2A of the vehicle 2 and stored in the tire/wheel assembly 3, the installation position of the power receiving device 30 is not limited to the above example. For example, the power receiving device 30 may be arranged inside the tread portion 13 of the tire 10 or inside the tread portion 13 in the tire radial direction. Further, for example, the power receiving device 30 may be arranged inside the rim portion 21 of the wheel 20 in the wheel radial direction or outside the wheel radial direction. According to these configurations, by changing the internal pressure of the tire 10 to the second internal pressure that is lower than the first internal pressure, the distance between the power transmitting device 40 and the power receiving device 30 located outside the tire 10 in the tire radial direction is reduced. can be brought closer, and the magnetic field reaching the power receiving device 30 can be increased. Furthermore, by changing the internal pressure of the tire 10 to a second internal pressure that is lower than the first internal pressure, the ground contact area of the tire 10 is increased and the area to which power is supplied is widened.

(compressor configuration)
Next, an example configuration of the compressor in the wireless power receiving system 1 according to one embodiment of the present invention will be described in detail.

The compressor 50 fills the tire 10 with gas or releases the gas from the tire 10 under the control of the control device 60 . Compressor 50 is connected with tire 10 so that ventilation is possible. The compressor 50 is connected to the tire 10 so as to allow ventilation by being connected to the valve 27 of the wheel 20 on which the tire 10 is mounted, for example, by means of a rubber tube or the like. The compressor 50 may further include a measuring section for measuring the internal pressure of the tire 10 . The measurement unit is, for example, a pressure gauge, but may be any device capable of calculating the internal pressure of the tire 10, such as a flow meter. Thereby, the compressor 50 can transmit the internal pressure of the tire 10 measured by the pressure gauge to the control device 60 . Further, when a predetermined internal pressure is designated by the control device 60, the compressor 50 controls the tire according to the control of the control device 60, which will be described later, so that the internal pressure of the tire 10 measured by the pressure gauge becomes the predetermined internal pressure. The tire 10 can be filled with gas or vented from the tire 10 .

(Configuration of control device)
Next, the configuration of an example of the control device in the wireless power receiving system 1 according to one embodiment of the present invention will be described in detail.

FIG. 4 is a functional block diagram schematically showing the configuration of control device 60. As shown in FIG. The control device 60 is an ECU (Electronic Control Unit) that controls the vehicle 2, but is not limited to this and may be any electronic device. The control device 60 may be installed integrally with the vehicle 2 or may be installed detachably.

The control device 60 includes a control section 61 , a storage section 62 , a communication section 63 , an output section 64 and an input section 65 . The control unit 61 is electrically connected to each of the storage unit 62 , the communication unit 63 , the output unit 64 and the input unit 65 .

Control unit 61 includes at least one processor to provide control and processing power to perform various functions. The control unit 61 can be a general-purpose processor such as a CPU that executes a program defining a control procedure, or a dedicated processor that specializes in processing each function. The control unit 61 can control each of a storage unit 62, a communication unit 63, an output unit 64, and an input unit 65, which will be described later, in order to realize the functions thereof.

The storage unit 62 stores processing for controlling each function of the control device 60, information and programs used in the processing, and the like. The storage unit 62 can be, for example, a semiconductor memory, a magnetic memory, an optical memory, or the like. The storage unit 62 can function, for example, as a main storage device or an auxiliary storage device. The storage unit 62 may be a cache memory or the like included in the control unit 61 . Moreover, the memory|storage part 62 may be a volatile memory|storage device, and may be a non-volatile memory|storage device. In the present embodiment, the storage unit 62 stores, for example, information used for controlling the internal pressure of the tire 10, as will be detailed later.

The communication unit 63 is a CAN communication module, a wired LAN (local area network) communication module, a wireless LAN communication module, and a mobile communication module compatible with mobile communication standards such as 4G (Generation) and 5G. Contains modules. As a result, the communication unit 63, based on the control of the control unit 61, controls electronic devices installed inside the vehicle 2, such as the power receiving device 30 and the compressor 50, or external devices such as a GPS satellite and a web system. can communicate with electronic devices located in the

The output unit 64 outputs information by sound, vibration, light, image, or the like under the control of the control unit 61 . The output unit 64 may include, for example, at least one of a speaker, vibrator, light, display device, and the like. The output unit 64 can output information on whether or not the power receiving device 30 can receive wireless power supply from the power transmitting device 40, information on power being supplied to the power receiving device 30, information on the internal pressure of the tire 10, or the like. . For example, when the power receiving device 30 is in a position where power can be received wirelessly, the control unit 61 displays information on the output unit 64, which is a display device, to notify the user that power can be supplied wirelessly. be able to.

The input unit 65 receives an input operation from the user. The input unit 65 may include at least one of, for example, an input device such as a touch panel, a microphone that accepts voice input, and a camera that accepts gesture input. Upon receiving an input operation by the user, the input unit 65 transmits the input operation to the control unit 61 as electronic information. The input operation may include, for example, an instruction to start the process of changing the internal pressure of the tire 10 .

Control of the compressor 50 by the controller 60 will be described below. The control device 60 controls the compressor 50 to change the internal pressure of the tire 10 . The control device 60 transmits a control signal from the communication section 63 to the compressor 50 . The control signal can be any signal such as a signal specifying a target value of the internal pressure of the tire 10 or a signal specifying the operation of the compressor 50 . The compressor 50 causes the tire 10 to be inflated or discharged from the tire 10 based on the control signal received from the control device 60 . Thereby, the internal pressure of the tire 10 is changed to a predetermined internal pressure by the control device 60 . The predetermined internal pressure can be set to any numerical value, numerical range, or a combination thereof within the range of air pressure appropriate for use of the tire 10, which is described in industrial standards such as the JATMA YEAR BOOK. can. The predetermined internal pressure can be set, for example, as an arbitrary numerical value within the range defined in the "air pressure-load capacity correspondence table" in the JATMA YEAR BOOK, a numerical range, or a combination thereof.

The predetermined internal pressure includes at least the internal pressure specified when power receiving device 30 is at a position capable of receiving power wirelessly and the internal pressure specified otherwise. In this specification, the internal pressure specified when power is not being supplied wirelessly to the power receiving device 30, such as during normal driving, is referred to as a first internal pressure, and is a position where the power receiving device 30 can wirelessly receive power. The internal pressure specified in the case of is referred to as the second internal pressure. The second internal pressure is set to a numerical value or numerical range lower than the first internal pressure, or a combination thereof. Further, the first internal pressure includes a plurality of numerical values that differ according to the running state of the vehicle 2, the road surface state, etc., such as the first internal pressure when the vehicle 2 is running and the first internal pressure when the vehicle 2 is stopped. or numerical ranges may be included. The second internal pressure includes the running state of the vehicle 2, the road surface state, the power supplied by wireless power supply, such as the second internal pressure when the vehicle 2 is running and the second internal pressure when the vehicle 2 is stopped. A plurality of numerical values or numerical ranges may be included that differ depending on the strength of, etc. The internal pressure included in the predetermined internal pressure is not limited to the first internal pressure and the second internal pressure. The number of internal pressures set as predetermined internal pressures and the setting conditions can be arbitrarily determined.

Control device 60 determines whether or not power receiving device 30 is at a position where power can be received wirelessly.

For example, based on information received from GPS satellites, the control device 60 can determine whether the power receiving device 30 is at a position where power can be received wirelessly. Control device 60 identifies the position of vehicle 2 based on information received from GPS satellites. For example, when the vehicle 2 is on a road, a parking lot, or the like where the power transmission device 40 is installed, the control device 60 compares with map information or the like stored in advance, and determines the location where the power reception device 30 can wirelessly receive power. can be determined to be in

Further, for example, the control device 60 can determine whether or not the power receiving device 30 is at a position where power can be received wirelessly, based on information indicating the position of the power transmitting device 40 that wirelessly supplies power to the power receiving device 30 . can. Information indicating the position of the power transmission device 40 may be included in a predetermined signal transmitted from the power transmission device 40 itself or from a device installed near the power transmission device 40 . For example, while receiving a predetermined signal, the control device 60 can determine that the power receiving device 30 is at a position capable of receiving power wirelessly. The predetermined signal may be a signal indicating the start position and end position of the road on which the power transmission device 40 is installed. Control device 60 determines that power receiving device 30 is at a position where power can be received wirelessly when a signal indicating the start position is received, and power receiving device 30 wirelessly receives power when a signal indicating the end position is received. It can be determined that it is not in a possible position.

Further, for example, the control device 60 can determine whether or not the power receiving device 30 is at a position where power can be received wirelessly, based on the intensity of power wirelessly supplied to the power receiving device 30 . The power intensity is, for example, power, but is not limited thereto, and can be an arbitrary numerical value representing the intensity of power wirelessly supplied to the power receiving device 30, such as power amount, voltage, current, magnetic flux amount, or magnetic flux density. can do. The control device 60 can, for example, communicate with the power receiving device 30 to acquire information about the intensity of power wirelessly supplied to the power receiving device 30 . For example, when the power receiving device 30 continues to receive power equal to or greater than a predetermined amount for a certain period of time, the control device 60 can determine that the power receiving device 30 is in a position where power can be received wirelessly.

When the control device 60 determines that the power receiving device 30 is in a position where the power can be received wirelessly when the internal pressure of the tire 10 is the first internal pressure, the control device 60 controls the compressor 50 to reduce the internal pressure of the tire 10 to the first pressure. The internal pressure is changed to a second internal pressure that is lower than the internal pressure. As a result, the outer diameter of the tire 10 is reduced and the distance between the power receiving device 30 and the power transmitting device 40 is shortened, so that the transmission efficiency of wireless power supply can be improved. Furthermore, by changing the internal pressure of the tire 10 to a second internal pressure that is lower than the first internal pressure, the ground contact area of the tire 10 is increased and the area to which power is supplied is widened.

On the other hand, if control device 60 determines that power receiving device 30 is not in a position where power can be received wirelessly when the internal pressure of tire 10 is the second internal pressure, control device 60 controls compressor 50 to increase the internal pressure of tire 10 . Change to the first internal pressure. As a result, the contact area of the tire 10 is reduced, so that the rolling resistance coefficient of the tire 10 is reduced, and the fuel efficiency of the tire 10 can be improved.

Although the control device 60 automatically changes the internal pressure of the tire 10 based on the determination result as to whether or not the power receiving device 30 is at a position capable of wirelessly receiving power, the present invention is not limited to this. For example, the control device 60 changes the internal pressure of the tire 10 only when the input unit 65 receives an input operation from the user in addition to the determination result as to whether or not the power receiving device 30 is at a position where power can be received wirelessly. may be changed. For example, when the power receiving device 30 is in a position where power can be received wirelessly, the control device 60 displays information on the output unit 64, which is a display device, to notify the user that power can be received wirelessly. After that, when an input to change the internal pressure of the tire 10 is received by the input unit 65 from the user, the internal pressure of the tire 10 can be changed. As a result, for example, when the user is driving the vehicle 2, it is possible to avoid changes in the internal pressure of the tire 10 at timing unintended by the user, thereby preventing deterioration in safety. Further, for example, when the user wants to give priority to the fuel consumption performance of the tire 10 over the transmission efficiency of wireless power supply, the user can decide not to change the internal pressure of the tire 10, thereby improving the convenience of the wireless power receiving system 1.

The control device 60 can transmit a signal to change the speed of the vehicle 2 when changing the internal pressure of the tire 10 . For example, when the vehicle 2 is automatically driven, the control device 60 transmits a signal for changing the speed of the vehicle 2 to a power source such as an engine or a motor of the vehicle 2 . For example, the control device 60 can reduce the speed of the vehicle 2 when the internal pressure of the tire 10 changes from a first internal pressure to a second internal pressure lower than the first internal pressure. As a result, even when the internal pressure of the tire 10 is lowered, the burden on the tire 10 can be reduced or the safety of the vehicle 2 can be improved. Furthermore, the control device 60 can increase the amount of power supplied to the power receiving device 30 by increasing the time during which the power receiving device 30 is positioned above the power transmitting device 40 by reducing the speed of the vehicle 2 . can.

(Control Method for Wireless Power Receiving System)
Next, a control method of the wireless power receiving system 1 according to one embodiment of the present invention will be described in detail. FIG. 5 is a flow chart showing the flow of the control method for the wireless power receiving system according to one embodiment of the present invention. This control method can be executed by the control device 60 included in the wireless power receiving system 1, for example.

Step S101: The controller 60 controls the compressor 50 to change the internal pressure of the tire 10 to the first internal pressure.

Step S102: The control device 60 determines whether or not the power receiving device 30 is at a position where power can be received wirelessly. Specifically, based on the information received from the GPS satellite, based on the information indicating the position of the power transmitting device 40, or based on the strength of the power wirelessly supplied to the power receiving device 30, the control device 60 It is possible to determine whether or not the power receiving device 30 is at a position where power can be received wirelessly. When the control device 60 determines that the power receiving device 30 is not in a position where the power can be received wirelessly when the internal pressure of the tire 10 is the first internal pressure (step S102-No), the internal pressure of the tire 10 is changed to the first internal pressure. The determination is repeated without changing from .

Step S103: When the control device 60 determines that the power receiving device 30 is in a position where power can be received wirelessly when the internal pressure of the tire 10 is the first internal pressure (step S102-Yes), the control device 60 controls the compressor 50. , the internal pressure of the tire 10 is changed to a second internal pressure lower than the first internal pressure.

Step S104: When the internal pressure of the tire 10 is the second internal pressure, the control device 60 determines whether or not the power receiving device 30 is at a position capable of receiving power wirelessly. When the internal pressure of the tire 10 is the second internal pressure, if it is determined that the power receiving device 30 is in a position where power can be received wirelessly (step S104-Yes), the internal pressure of the tire 10 is not changed from the second internal pressure. , the determination is repeated.

Step S105: If the control device 60 determines that the power receiving device 30 is not in a position where power can be received wirelessly when the internal pressure of the tire 10 is the second internal pressure (step S104—No), the control device 60 controls the compressor 50. , the internal pressure of the tire 10 is changed to the first internal pressure, and the process ends.

A modification of the wireless power receiving system 1 according to one embodiment of the present invention will be described below. FIG. 6 shows a schematic diagram schematically showing a modification of the wireless power receiving system 1 according to one embodiment of the present invention using a cross section in the tire width direction. In the modification of the wireless power receiving system 1, unlike the wireless power receiving system 1 shown in FIG. 1, a power receiving device 30, a compressor 50, a and a control device 60 are installed and housed. The control device 60 is, for example, a control device for the in-wheel motor 4, but is not limited to this and may be any electronic device. In the modified example of the wireless power receiving system 1, the same reference numerals are given to the members/parts common to the wireless power receiving system 1 shown in FIG. 1, and the description thereof will be omitted.

The in-wheel motor 4 is integrated with the hub and installed in the accommodation portion of the wheel 20 to drive the tire 10 and the wheel 20 . As shown in FIG. 6 , the in-wheel motor 4 may be mounted on the wheel 20 , and a part of the in-wheel motor 4 may be positioned outside the accommodating portion of the wheel 20 in the tire width direction. The power receiving device 30 is connected to the in-wheel motor 4 via a conductive wire or the like to convert the power generated in the power receiving coil 31 into DC power and supply the DC power to the in-wheel motor 4. can.

When the wheel 20 is attached to the in-wheel motor 4 , the power receiving device 30 included in the in-wheel motor 4 can be accommodated inside the rim portion 21 of the wheel 20 in the tire radial direction. As a result, the vehicle 2 can be driven so that the contact surface of the tire 10 passes over the power transmission device 40 provided on the road or the like, or the vehicle 2 can be stopped so as to be positioned over the power transmission device 40. The power receiving device 30 can supply the in-wheel motor 4 with the power wirelessly received from the power transmitting device 40 . As a result, the power transmission path from the power receiving device 30 to the motor can be shortened, and the power loss in the power transmission path can be reduced.

In this modification, the control device 60 determines whether or not the power receiving device 30 is at a position where power can be received wirelessly. When the control device 60 determines that the power receiving device 30 is in a position where the power can be received wirelessly when the internal pressure of the tire 10 is the first internal pressure, the control device 60 controls the compressor 50 to reduce the internal pressure of the tire 10 to the first pressure. The internal pressure is changed to a second internal pressure that is lower than the internal pressure. As a result, the outer diameter of the tire 10 is reduced and the distance between the power receiving device 30 and the power transmitting device 40 is shortened, so that the transmission efficiency of wireless power supply can be improved. On the other hand, if control device 60 determines that power receiving device 30 is not at a position where power can be received by wireless power supply when the internal pressure of tire 10 is the second internal pressure, control device 60 controls compressor 50 to increase the internal pressure of tire 10 . to the first internal pressure. As a result, the rolling resistance coefficient of the tire 10 is reduced, and the fuel efficiency of the tire 10 can be improved.

In the present invention, when the cross-sectional width SW of the tire 10 is less than 165 (mm), the ratio SW/OD of the cross-sectional width SW to the outer diameter OD of the tire 10 is 0.26 or less. is preferred. Further, in the present invention, when the cross-sectional width SW of the tire 10 is 165 (mm) or more, the cross-sectional width SW (mm) and the outer diameter OD (mm) of the tire 10 are obtained from the relational expression (1), OD (mm )≧2.135×SW (mm)+282.3 (mm).

By satisfying the above ratio SW/OD or the relational expression (1), the cross-sectional width SW of the tire 10 becomes relatively small with respect to the outer diameter OD of the tire 10, thereby reducing air resistance and narrowing the cross-sectional width. Accordingly, the vehicle space can be secured, and in particular, the installation space for the drive components can be secured in the vicinity of the inner side where the tire 10 is mounted on the vehicle.

Further, by satisfying the ratio SW/OD or the relational expression (1), the outer diameter of the tire 10 becomes relatively large with respect to the cross-sectional width SW of the tire 10, thereby reducing the rolling resistance. Since the wheel shaft becomes higher due to the larger diameter and the space under the floor is expanded, the space for the trunk of the vehicle 2 and the installation space for the driving parts can be secured.

As described above, by satisfying the ratio SW/OD or the relational expression (1), low fuel consumption can be achieved with respect to the supplied electric energy, and a large vehicle space can be secured. .

In the present invention, the tire 10 has a cross-sectional width SW (mm) and an outer diameter OD (mm) that satisfy the relational expression (2), OD (mm)≧−0.0187×SW (mm) ² +9. It is preferable to satisfy 15×SW (mm)−380 (mm).

By satisfying the above relational expression (2), the cross-sectional width SW of the tire 10 becomes relatively small with respect to the outer diameter OD of the tire 10, thereby reducing air resistance. In particular, it is possible to secure an installation space for drive components in the vicinity of the inner side of the tire 10 where the tire 10 is mounted on the vehicle.

Further, by satisfying the above relational expression (2), the outer diameter of the tire 10 becomes relatively large with respect to the cross-sectional width SW of the tire 10, thereby reducing the rolling resistance. Since the shaft is raised and the space under the floor is expanded, the space for the trunk of the vehicle 2 and the installation space for the driving parts can be secured.

As described above, by satisfying the above relational expression (2), it is possible to achieve low fuel consumption with respect to the supplied electrical energy, and also to secure a large vehicle space.

In the present invention, the tire 10 preferably satisfies the ratio SW/OD and/or the relational expression (2), or preferably satisfies the relational expression (1) and/or the relational expression (2).

In each of the above examples, the tire 10 preferably satisfies the ratio SW/OD and/or the relational expression (2) when the internal pressure is 250 kPa or more, or the relational expression (1) and/or Alternatively, it is preferable to satisfy the relational expression (2).

In each example described above, the tire 10 is preferably used at an internal pressure of 250 kPa or more. In this case, in particular, when the internal pressure of the tire 10 is 250 kPa or more, the tire 10 satisfies the ratio SW/OD and/or the relational expression (2), or the relational expression (1) and/or the relational expression (2 ) is preferably satisfied. Thereby, both the rolling resistance value of the tire and the tire weight can be reduced. Therefore, both power supply efficiency and low fuel consumption can be favorably achieved.

In each of the above examples, the tire 10 has a cross-sectional area of the bead filler 11B in the tire width direction (the cross-sectional area of the bead filler 11B in the cross section shown in FIG. cross-sectional area) is preferably 1 to 8 times. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
In the case of a sandwiched bead core structure that sandwiches the carcass from the inside and outside in the tire width direction, the total area of the bead cores on the inside and outside in the width direction of the carcass is the cross-sectional area of the bead core in the tire width direction.
By setting the cross-sectional area of the bead filler 11B in the tire width direction within the above range, it is possible to reduce the volume of the bead filler 11B, which is a highly rigid member, reduce the longitudinal spring coefficient of the tire, and improve ride comfort. Moreover, the weight of the bead filler 11B can be reduced to reduce the weight of the tire 10, so that the rolling resistance of the tire 10 can be further reduced.
In particular, in narrow-width, large-diameter tires that satisfy the above relational expression (1) or (2), the tensional rigidity of the belt is high, and the tensional rigidity of the tire side portion is lower than that of the belt. In addition, by setting the cross-sectional area of the bead filler 11B in the tire width direction within a predetermined range, the effect of reducing the longitudinal spring coefficient is greatly increased.
Here, if the cross-sectional area of the bead filler in the tire width direction is more than eight times the cross-sectional area of the bead core in the tire width direction, the volume of the bead filler, which is a highly rigid member, becomes large, and the vertical spring coefficient of the tire is not sufficiently reduced. Riding comfort may deteriorate.
On the other hand, if the cross-sectional area of the bead filler in the tire width direction is less than 1 time the cross-sectional area of the bead core in the tire width direction, the rigidity of the bead portion is significantly reduced, and the lateral spring coefficient is excessively reduced, thereby ensuring steering stability. There is a risk that you will not be able to

In each of the examples described above, the tire 10 defines the width of the bead filler 11B in the tire width direction at the center position in the tire radial direction as “BFW” (see FIG. 2), and the maximum width of the bead core 11A in the tire width direction as “BDW” (see FIG. 2). 2), when
0.1≤BFW/BDW≤0.6
is preferably satisfied. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
By reducing the volume of the bead filler 11B while maintaining the bead filler height by setting the ratio BFW/BDW to 0.6 or less, the longitudinal spring coefficient is reduced while maintaining the rigidity in the tire rotation direction. , the ride comfort can be improved, and the weight of the tire 10 can be reduced.
On the other hand, by setting the ratio BFW/BDW to 0.1 or more, it is possible to ensure the rigidity of the bead portion 11, maintain the lateral spring coefficient, and further ensure steering stability.

In each of the examples described above, the tire 10 has a height of the bead filler 11B in the tire radial direction of "BFH" (see FIG. 2), and a tire cross-sectional height (section height) of the tire 10 of "SH" (see FIG. 2). When
0.1≤BFH/SH≤0.5
is preferably satisfied. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
By setting the ratio BFH/SH to 0.5 or less, the radial height of the bead filler 11B, which is a highly rigid member, is reduced, effectively reducing the longitudinal spring coefficient of the tire 10, and improving ride comfort. can be made
On the other hand, by setting the ratio BFH/SH to 0.1 or more, it is possible to ensure the rigidity of the bead portion 11, maintain the lateral spring coefficient, and further ensure steering stability.
Here, the tire cross-sectional height SH is the difference between the outer diameter of the tire 10 and the rim diameter in a no-load state when the tire 10 is mounted on a rim and filled with an internal pressure specified for each vehicle on which the tire is mounted. 1/2 of

The height BFH (see FIG. 2) of the bead filler 11B in the tire radial direction is preferably 45 mm or less. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.

In each of the above examples, the tire 10 has a gauge Ts (see FIG. 2) of the sidewall portion 12 at the tire maximum width portion, and a bead width Tb at the center position of the bead core 11A in the tire radial direction (the width of the bead portion 11 in the tire width direction). width, see FIG. 2) is preferably 15% or more and 60% or less. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
The term "tire maximum width portion" refers to the maximum width position in the cross section in the tire width direction when the tire 10 is mounted on the rim and placed in an unloaded state.
Gauge Ts (see FIG. 2) is the total thickness of all members such as rubber, reinforcing members, and inner liner.
By setting the ratio Ts/Tb within the above range, it is possible to moderately reduce the rigidity at the tire maximum width portion where bending deformation under tire load is large, reduce the vertical spring coefficient, and improve ride comfort. .
That is, when the ratio Ts/Tb is more than 60%, the gauge Ts (see FIG. 2) of the sidewall portion 12 at the tire maximum width portion increases, the rigidity of the sidewall portion 12 increases, and the longitudinal spring coefficient increases. It may become expensive. On the other hand, if the ratio Ts/Tb is less than 15%, the lateral spring coefficient may be too low, making it impossible to ensure steering stability.

In each of the above examples, the tire 10 preferably has a gauge Ts (see FIG. 2) of the sidewall portion 12 at the tire maximum width portion of 1.5 mm or more. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
By setting the width to 1.5 mm or more, it is possible to moderately maintain the rigidity at the tire maximum width portion, suppress a decrease in the lateral spring coefficient, and further ensure steering stability.

In each of the above examples, the tire 10 preferably has a diameter Tbc of the bead core 11A (in this example, the maximum width of the bead core in the tire width direction, see FIG. 2) of 3 mm or more and 16 mm or less. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
By making it 3 mm or more, it is possible to achieve weight reduction while ensuring bending rigidity and torsional rigidity on the flange 23 (see FIG. 3) of the rim, while making it 16 mm or less increases weight. It is possible to secure the steering stability while suppressing the
In the case of a structure in which the bead core 11A is divided into a plurality of small bead cores by the carcass 14, the distance between the widthwise innermost end and the outermost end of all the small bead cores may be Tbc.

In each of the above examples, the tire 10 preferably has a contact area of 8000 mm ² or more when the maximum load specified for each vehicle on which the tire is mounted is applied. As a result, it is possible to achieve both a reduction in the rolling resistance value of the tire 10 and a reduction in tire weight, and it is possible to suitably achieve both power supply efficiency and low fuel consumption. In addition, it is possible to secure the tire axial force and improve the stability and safety of the vehicle.

In each of the above examples, the tire 10 preferably has a Young's modulus of 40000 MPa or more of the belt cords 15c. As a result, the carcass structure and belt rigidity can be optimized, and the strength of the tire 10 that can be used even at high internal pressure can be ensured. Moreover, both power supply efficiency and low fuel consumption can be favorably achieved.

In each of the examples described above, the inner liner 16 of the tire 10 preferably has a thickness of 0.6 mm or more. As a result, air leakage can be suppressed in a high internal pressure state. Moreover, both power supply efficiency and low fuel consumption can be favorably achieved.

In each of the above examples, the tire 10 has a ratio Ts/Tc of the gauge Ts (see FIG. 2) of the sidewall portion 12 at the tire maximum width portion to the diameter Tc (see FIG. 2) of the carcass cord 14c of 4 or more. It is suitable in it being 12 or less. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
By setting the ratio Ts/Tc within the above range, it is possible to moderately reduce the rigidity at the tire maximum width portion where bending deformation under tire load is large, reduce the longitudinal spring coefficient, and improve ride comfort. .
That is, when the ratio Ts/Tc exceeds 12, the gauge Ts (see FIG. 2) of the sidewall portion 12 at the tire maximum width portion becomes large, and the rigidity of this portion becomes high, resulting in a high longitudinal spring coefficient. There is a risk that it will be lost. On the other hand, if the ratio Ts/Tc is less than 4, the lateral spring coefficient will be too low, and steering stability may not be ensured.

In each of the above-described examples, the tire 10 has the distance Ta (see FIG. 2) in the tire width direction from the surface of the carcass cords 14c to the outer surface of the tire at the maximum width portion of the tire. The ratio Ta/Tc to Tc (see FIG. 2) is preferably 2 or more and 8 or less. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
By setting the ratio Ta/Tc to 8 or less, the gauge Ts (see FIG. 2) of the sidewall portion 12 at the tire maximum width portion is reduced, the rigidity of the sidewall portion 12 is reduced, and the longitudinal spring coefficient is reduced. can be reduced, and ride comfort can be further improved. On the other hand, by setting the ratio Ta/Tc to 2 or more, it is possible to secure a lateral spring coefficient and to secure more steering stability.
“Ta” (see FIG. 2) is the distance in the tire width direction from the surface of the outermost carcass cord 14c in the width direction to the outer surface of the tire at the tire maximum width portion.
That is, when the carcass turn-up portion 14B extends radially outward from the tire maximum width portion, the distance in the tire width direction from the surface of the carcass cord 14c of the portion forming the carcass turn-up portion 14B to the tire outer surface is Ta. .

In each of the above examples, the tire 10 preferably has a diameter Tc (see FIG. 2) of the carcass cords 14c of 0.2 mm or more and 1.2 mm or less. As a result, both power supply efficiency and fuel efficiency can be favorably achieved.
By making it 1.2 mm or less, the gauge Ts of the sidewall portion 12 with respect to the diameter Tc of the carcass cord 14c can be made smaller, and the longitudinal spring coefficient can be reduced. Steering stability can be ensured by securing the gauge Ts of the sidewall portion 12 with respect to the diameter Tc of the carcass cord 14c and increasing the lateral spring coefficient.

As described above, the wireless power receiving system 1 according to one embodiment of the present invention includes the tire/wheel assembly 3 including the tire 10 and the wheel 20, and the tire/wheel assembly 3. It includes a power receiving device 30 that receives power wirelessly supplied from the outside in the radial direction, a compressor 50 that is air-permeably connected to the tire 10, and a control device 60 that controls the compressor 50 to change the internal pressure of the tire 10. . The control device 60 determines whether or not the power receiving device 30 is at a position capable of wirelessly receiving power, and if the internal pressure of the tire 10 is the first internal pressure, the power receiving device 30 is at a position capable of wirelessly receiving power. When the determination is made, the internal pressure of the tire 10 is changed to a second internal pressure lower than the first internal pressure, and when the internal pressure of the tire 10 is the second internal pressure, the power receiving device 30 is not in a position capable of wirelessly receiving power. If so, the internal pressure of the tire 10 is changed to the first internal pressure. According to this configuration, the position of the power receiving device 30 housed in the tire/wheel assembly 3 can be changed depending on whether or not the power receiving device 30 is at a position where power can be received wirelessly. As a result, when the power receiving device 30 is at a position where power can be received by wireless power supply, the internal pressure of the tire 10 is reduced, the distance between the power receiving device 30 and the power transmitting device 40 is shortened, and the transmission efficiency of wireless power feeding is improved. When the power receiving device 30 is not at a position where power can be received by wireless power supply, the internal pressure of the tire 10 is increased to decrease the rolling resistance coefficient of the tire 10, thereby improving the fuel efficiency of the tire 10. Therefore, the power receiving device 30 housed in the tire/wheel assembly 3 can efficiently receive power wirelessly supplied from the power transmitting device 40 installed on a road or the like, and the power receiving efficiency in wireless power feeding is improved. do.

In the wireless power receiving system 1 according to one embodiment of the present invention, the control device 60 preferably determines whether or not the power receiving device 30 is at a position where power can be received wirelessly, based on information received from GPS satellites. . According to such a configuration, it is possible to determine whether or not the power receiving device 30 is at a position where power can be received wirelessly, based on highly versatile information that can be received from GPS satellites.

In the wireless power receiving system 1 according to one embodiment of the present invention, the control device 60 allows the power receiving device 30 to wirelessly receive power based on information indicating the position of the power transmitting device 40 that wirelessly supplies power to the power receiving device 30. It is preferable to determine whether it is in position. According to such a configuration, since the determination is made after specifying the position of the power transmission device 40, it is possible to determine with high accuracy whether or not the power reception device 30 is at a position where power can be received wirelessly.

In the wireless power receiving system 1 according to one embodiment of the present invention, the control device 60 determines whether or not the power receiving device 30 is at a position where power can be received wirelessly, based on the intensity of power wirelessly supplied to the power receiving device 30 . is preferably determined. With such a configuration, determination is made based on the intensity of the power actually received by the power receiving device 30, so whether or not the power receiving device 30 is at a position where power can be received wirelessly can be determined with higher accuracy.

In the wireless power receiving system 1 according to one embodiment of the present invention, the tire 10 has a tread portion 13 made of a non-magnetic material, and the wheel 20 has a rim portion 21 at least partially made of a non-magnetic material. In addition, the power receiving device 30 is preferably accommodated inside the rim portion 21 of the wheel 20 in the tire radial direction. According to such a configuration, when the power transmission device 40 is a device that generates a magnetic field, the tire 10 can reach the power reception device 30 housed in the tire/wheel assembly 3 by the time the magnetic field generated by the power transmission device 40 reaches the power receiving device 30 . Attenuation through the tread portion 13 of the wheel 20 and the rim portion 21 of the wheel 20 can be reduced.

In the wireless power receiving system 1 according to one embodiment of the present invention, the wheel 20 preferably includes a slip ring 29 for ventilably connecting the compressor 50 with the tire 10 . According to such a configuration, when the tire 10 rotates in the tire circumferential direction but the compressor 50 is mounted at a position where it does not rotate, the ventilation path between the tire 10 and the compressor 50 is prevented from being twisted and damaged. can be prevented.

In the wireless power receiving system 1 according to one embodiment of the present invention, the power receiving device 30 preferably receives power supplied by an electromagnetic induction method. According to this configuration, by housing the power receiving device in the tire/wheel assembly, the distance between the power receiving device and the power transmitting device provided on the road or the like can be set within the range of the distance at which wireless power supply by electromagnetic induction can be performed. can be As a result, in wireless power supply, for example, an electromagnetic induction method, which has higher transmission efficiency than an electric field coupling method, can be adopted. As a result, wireless power supply can be performed with high transmission efficiency.

A method for controlling the wireless power receiving system 1 according to an embodiment of the present invention comprises steps of determining whether or not the power receiving device 30 is in a position where power can be received wirelessly by the control device 60; when the internal pressure of the tire 10 is a first internal pressure and it is determined that the power receiving device 30 is in a position where power can be received wirelessly, changing the internal pressure of the tire 10 to a second internal pressure lower than the first internal pressure; changing the internal pressure of the tire 10 to the first internal pressure when the control device 60 determines that the power receiving device 30 is not in a position where power can be received wirelessly when the internal pressure of the tire 10 is the second internal pressure; including. According to such a configuration, the position of the power receiving device 30 housed in the tire/wheel assembly 3 can be changed depending on whether or not it is at a position where power can be received wirelessly. As a result, the power receiving device 30 housed in the tire/wheel assembly 3 can efficiently receive power wirelessly supplied from the power transmitting device 40 installed on a road or the like, and the power receiving efficiency in wireless power feeding can be improved. improves.

A tire-wheel assembly 3 according to one embodiment of the present invention is a tire-wheel assembly 3 composed of a tire 10 and a wheel 20, is accommodated in the tire-wheel assembly 3, and is arranged in the tire radial direction from the tire 10. It includes a power receiving device 30 that receives power wirelessly supplied from the outside, a compressor 50 that is connected to the tire 10 so as to allow ventilation, and a control device 60 that controls the compressor 50 to change the internal pressure of the tire 10. - 特許庁The control device 60 determines whether or not the power receiving device 30 is at a position capable of wirelessly receiving power, and if the internal pressure of the tire 10 is the first internal pressure, the power receiving device 30 is at a position capable of wirelessly receiving power. When the determination is made, the internal pressure of the tire 10 is changed to a second internal pressure lower than the first internal pressure, and when the internal pressure of the tire 10 is the second internal pressure, the power receiving device 30 is not in a position capable of wirelessly receiving power. If so, the internal pressure of the tire 10 is changed to the first internal pressure. According to such a configuration, the position of the power receiving device 30 housed in the tire/wheel assembly 3 can be changed depending on whether or not it is at a position where power can be received wirelessly. As a result, the power receiving device 30 housed in the tire/wheel assembly 3 can efficiently receive power wirelessly supplied from the power transmitting device 40 installed on a road or the like, and the power receiving efficiency in wireless power feeding can be improved. improves.

Although the present invention has been described with reference to drawings and embodiments, it should be noted that various variations and modifications can be easily made based on the present invention by those skilled in the art. Therefore, it should be noted that these variations and modifications are included within the scope of the present invention. For example, configurations or functions included in each embodiment or each example can be rearranged so as not to be logically inconsistent. In addition, 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 present invention, an example in which the power receiving device 30 is wirelessly supplied with power by electromagnetic induction from the power transmitting device 40 has been described, but this is not the only option. For example, the power receiving device 30 may be wirelessly supplied with power from the power transmitting device 40 by any method such as an electric field coupling method.

Also, for example, in the present invention, the vehicle 2 has been described as an automobile, but this is not the only option. Vehicles 2 include automobiles such as passenger cars, trucks, buses, and two-wheeled vehicles, agricultural vehicles such as tractors, construction or construction vehicles such as dump trucks, bicycles, and wheelchairs that can move with wheels and tires. It can be any vehicle.

Further, for example, in the present invention, the tire 10 has been described as being filled with air, but this is not the only option. For example, the tire 10 can be filled with a gas such as nitrogen. Further, for example, the tire 10 can be filled with any fluid, not limited to gas, including liquid, gel-like substance, granular material, or the like.

Further, for example, in the present invention, the tire 10 has been described as being a tubeless tire provided with the inner liner 16, but this is not the only option. For example, tire 10 may be a tube-type tire comprising a tube. Further, for example, the tire 10 may be an airless tire that is entirely or partially formed of the resin material described above and that is used without being filled with gas.

1: Wireless Power Receiving System 2: Vehicle 2A: Hub 3: Tire/Wheel Assembly 4: In-Wheel Motor 10: Tire 11: Bead Portion 11A: Bead Core 11B: Bead Filler 11c: Bead Wire 12 : sidewall portion 13: tread portion 14: carcass 14A: carcass body portion 14B: carcass folded portion 14c: carcass cord 14r: covering rubber 15: belt 15a, 15b: belt layer 15c: belt Code 15r: Coating rubber 16: Inner liner 20: Wheel 21: Rim part 22: Disc part 22A: Mounting part 22B: Spoke 23: Flange 24: Bead seat 25: Well 26 : hump 27: valve 28: wheel cover 29: slip ring 30: power receiving device 31: power receiving coil 32: power conversion circuit 33: power storage unit 34: control unit 40: power transmitting device 41: Power transmission coil 50: Compressor 60: Control device 61: Control unit 62: Storage unit 63: Communication unit 64: Output unit 65: Input unit

Claims (9)

a tire-wheel assembly comprising a tire and a wheel;
a power receiving device that is housed in the tire/wheel assembly and receives electric power that is wirelessly supplied from outside the tire in the tire radial direction;
a compressor ventilably connected to the tire;
a control device that controls the compressor to change the internal pressure of the tire;
with
The control device is
determining whether or not the power receiving device is in a position where power can be received wirelessly;
When the internal pressure of the tire is a first internal pressure and it is determined that the power receiving device is in a position where power can be received wirelessly, the internal pressure of the tire is changed to a second internal pressure lower than the first internal pressure. ,
A wireless power receiving system that changes the internal pressure of the tire to the first internal pressure when it is determined that the power receiving device is not in a position where power can be received wirelessly when the internal pressure of the tire is the second internal pressure. 2. The wireless power receiving system according to claim 1, wherein said control device determines whether said power receiving device is in a position where power can be received wirelessly, based on information received from a GPS satellite. 2. The control device according to claim 1, wherein the control device determines whether or not the power receiving device is in a position where power can be received wirelessly, based on information indicating a position of a power transmitting device that wirelessly supplies power to the power receiving device. wireless power receiving system. 2. The wireless power receiving system according to claim 1, wherein said control device determines whether said power receiving device is in a position capable of receiving power wirelessly, based on intensity of power wirelessly supplied to said power receiving device. The tire comprises a tread portion made of a non-magnetic material,
The wheel has a rim portion at least partially made of a non-magnetic material,
The wireless power receiving system according to any one of claims 1 to 4, wherein the power receiving device is housed inside the rim portion of the wheel in the tire radial direction. 6. The wireless power receiving system of any one of claims 1-5, wherein the wheel comprises a slip ring for ventilably connecting the compressor with the tire. The wireless power receiving system according to any one of claims 1 to 6, wherein the power receiving device receives power supplied by an electromagnetic induction method. A control method for the wireless power receiving system according to any one of claims 1 to 7,
a step of determining whether or not the power receiving device is in a position where power can be received wirelessly by the control device;
When the control device determines that the power receiving device is in a position where power can be received wirelessly when the internal pressure of the tire is a first internal pressure, the internal pressure of the tire is set to a second pressure lower than the first internal pressure. changing the internal pressure to
When the control device determines that the power receiving device is not in a position capable of receiving electric power wirelessly when the internal pressure of the tire is the second internal pressure, the step of changing the internal pressure of the tire to the first internal pressure. and,
A method of controlling a wireless power receiving system, comprising: A tire-wheel assembly comprising a tire and a wheel,
a power receiving device that is housed in the tire/wheel assembly and receives electric power that is wirelessly supplied from outside the tire in the tire radial direction;
a compressor ventilably connected to the tire;
a control device that controls the compressor to change the internal pressure of the tire;
with
The control device is
determining whether or not the power receiving device is in a position where power can be received wirelessly;
When the internal pressure of the tire is a first internal pressure and it is determined that the power receiving device is in a position where power can be received wirelessly, the internal pressure of the tire is changed to a second internal pressure lower than the first internal pressure. ,
A tire-wheel assembly that changes the internal pressure of the tire to the first internal pressure when it is determined that the power receiving device is not in a position where power can be received wirelessly when the internal pressure of the tire is the second internal pressure. .

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