JP2021022990A - Radio electric power reception system, control method of radio electric power reception system, and tire/wheel assembly - Google Patents

Abstract

To provide a radio electric power reception system, a control method of a radio electric power reception system and a tire/wheel assembly, each of which allows for improvement in efficiency of electric power reception in radio electric power supply.SOLUTION: A radio electric power reception system 1 comprises: a tire/wheel assembly 3 constituted of a tire 10 and a wheel 20; an electric power receiving device 30 which is housed in the tire/wheel assembly 3, and receives electric power supplied by radio; a compressor 50 connected to the tire 10 in such a manner that the compressor 50 can supply air to tire 10; and a control device 60 that controls the compressor 50 to change inner pressure of the tire 10. The control device 60 determines whether or not the electric power receiving device 30 is at a position where the device can receive electric power by radio, and when determined that the inner pressure is first inner pressure, changes the inner pressure to second inner pressure lower than the first inner pressure when determining that the electric power receiving device 30 is at the position where the device can receive electric power by radio, and when the inner pressure is the second inner pressure, changes the inner pressure to the first inner pressure when determining that the electric power receiving device 30 is not at the position where the device can receive electric power by radio.SELECTED DRAWING: Figure 1

Description

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

Conventionally, there is known a wireless power supply technology in which a power transmission device provided on a road or a parking lot or the like wirelessly supplies electric power to a power receiving device mounted on a vehicle. For example, Patent Document 1 discloses a vehicle that can be charged by a power transmission device provided on a road surface by providing a power receiving device on a wheel or tire of the vehicle.

Japanese Unexamined Patent Publication No. 2004-242380

Conventionally, in the wireless power supply technology for a power receiving device used in a vehicle, when the power receiving device installed in the vehicle and the power transmitting device installed on a road in the vertical downward direction are separated from each other, the power receiving efficiency May decrease.

An object of the present invention made in view of such circumstances is to provide a wireless power receiving system, a control method of the wireless power receiving system, and a tire / wheel assembly for improving the power receiving efficiency in wireless power feeding.

The wireless power receiving system according to the present invention is a power receiving device housed in a tire / wheel assembly composed of a tire and a wheel and receiving power wirelessly supplied from the tire radial outside of the tire. A compressor that is breathably connected to the tire, and a control device that controls the compressor to change the internal pressure of the tire.
The control device determines whether or not the power receiving device is in a position where it can receive power wirelessly, and when the internal pressure of the tire is the first internal pressure, the power receiving device can receive power wirelessly. When it is determined that the tire is in the position, the internal pressure of the tire is changed to the 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 the position is not possible, the internal pressure of the tire is changed to the first internal pressure.
According to the wireless power receiving system according to the present invention, the power receiving device housed in the tire / wheel assembly can efficiently receive the electric power supplied wirelessly from the power transmitting device provided on the road or the like, and wirelessly. Power receiving efficiency in power supply 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 it can receive wireless power based on the information received from the GPS satellite. According to such a configuration, it is possible to determine whether or not the power receiving device is in a position where it can receive power wirelessly, based on highly versatile information that can be received from GPS satellites.

In the wireless power receiving system according to the present invention, whether or not the control device is in a position where the power receiving device can receive power wirelessly based on information indicating the position of the power transmitting device that wirelessly supplies power to the power receiving device. It is preferable to determine. According to such a configuration, since the determination is made after the position of the power transmission device is specified, it is possible to determine with higher accuracy whether or not the power receiving device is in 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 it can receive wireless power based on the strength of the power supplied to the power receiving device wirelessly. preferable. According to such a configuration, since the determination is made based on the strength of the electric power actually received by the power receiving device, it is possible to determine with high accuracy whether or not the power receiving device is in a position where it can receive power wirelessly.

In the wireless power receiving system according to the present invention, the tire is provided with a tread portion made of a non-magnetic material, the wheel is provided with a rim portion made of at least a non-magnetic material, and the power receiving device is provided. It is preferable that the power receiving device is housed inside the rim portion of the wheel in the tire radial direction. According to such a 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 outside the tire in the radial direction of the tire. By the time, it is possible to reduce the damping through the tread portion of the tire and the rim portion of the wheel.

In the wireless power receiving system according to the present invention, it is preferable that the wheel includes a slip ring for breathably connecting the compressor to the tire. When the tire rotates in the tire circumferential direction, but the compressor is installed 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 electric power supplied by an electromagnetic induction method. According to such a configuration, wireless power supply can be performed with high transmission efficiency.

The control method of the wireless power receiving system according to the present invention includes a step of determining whether or not the power receiving device is in a position where it can receive power wirelessly by the control device, and a first step of determining the internal pressure of the tire by the control device. When it is determined that the power receiving device is in a position where power can be received wirelessly in the case of the internal pressure of the tire, the step of changing the internal pressure of the tire to the second internal pressure lower than the first internal pressure and the control device. 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, the step of changing the internal pressure of the tire to the first internal pressure is included. ..
According to the control method of the wireless power receiving system according to the present invention, the power receiving device housed in the tire / wheel assembly can efficiently receive the electric power supplied wirelessly from the power transmitting device provided on the road or the like. It is possible to improve the power receiving efficiency in wireless power supply.

The tire / wheel assembly according to the present invention is a tire / wheel assembly composed of tires and wheels, and is housed in the tire / wheel assembly and is wirelessly supplied from outside in the tire radial direction with respect to the tire. The power receiving device includes a power receiving device that receives the power, a compressor that is breathably connected to the tire, and a control device that controls the compressor to change the internal pressure of the tire. The control device wirelessly receives power from the power receiving device. When it is determined whether or not the tire is in a possible position and the internal pressure of the tire is the 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 determined to be the first internal pressure. When the internal pressure of the tire is changed to the second internal pressure lower than the internal pressure of the tire 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 internal pressure of the tire. Change to the first internal pressure.
According to the tire / wheel assembly according to the present invention, the power receiving device housed in the tire / wheel assembly can efficiently receive the electric power supplied wirelessly from the power transmission device provided on the road or the like. , The power receiving efficiency in wireless power supply is improved.

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

It is the schematic which shows schematicly which shows the wireless power receiving system which concerns on one Embodiment of this invention by using the cross section in the tire width direction. It is a tire width direction sectional view of an example of a tire in the wireless power receiving system which concerns on one Embodiment of this invention. It is a wheel width direction sectional view of an example of a wheel in the wireless power receiving system which concerns on one Embodiment of this invention. It is a functional block diagram which shows roughly the structure of an example of the control device in the wireless power receiving system which concerns on one Embodiment of this invention. It is a flow chart which shows the flow of the control method of the wireless power receiving system which concerns on one Embodiment of this invention. It is the schematic which shows the modification of the wireless power receiving system which concerns on one Embodiment of this invention schematicly using the cross section in the tire width direction.

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

(Configuration of wireless power receiving system)
FIG. 1 shows a schematic view schematically showing a wireless power receiving system 1 according to an 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 fully or partially automatic driving is performed. The power receiving device 30 is attached to the hub 2A of the vehicle 2, for example, and is housed in the tire / wheel assembly 3. The compressor 50 is ventilatedly connected to the tire 10 and more specifically to the cavity of the tire 10 by, for example, 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 tire 10, the wheel 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 examples shown in FIG. 1, depending on the application of the wireless power receiving system 1 and the like. Each of them may 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 located 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 is formed in an annular 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 alternating magnetic field toward the upper side of the road surface. However, in the drawing, the power transmission coil 41 is schematic. The power transmission coil 41 included in the power transmission device 40 is wound around a core such as a ferrite core to form an annular shape as a whole, but is not limited to this, and an alternating magnetic field such as a coil spring or an air core coil can be applied. 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, wireless power is supplied from the power transmission device 40 to the power reception device 30 by an electromagnetic induction method or the like.

An operation example of the wireless power receiving system 1 according to the embodiment of the present invention will be described with reference to FIG. The control device 60 identifies the position of the vehicle 2 based on, for example, information received from a GPS (Global Positioning System) satellite, 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 the electric power can be supplied by wireless power supply when the internal pressure of the tire 10 is the first internal pressure, the control device 60 controls the compressor 50 to control the internal pressure of the tire 10. Change to a second internal pressure that is lower than the first internal pressure. As a result, the outer diameter of the tire 10 becomes smaller, and the distance between the power receiving device 30 and the power transmitting device 40 becomes closer, so that the transmission efficiency of wireless power supply can be improved. Further, by changing the internal pressure of the tire 10 to a second internal pressure lower than the first internal pressure, the contact area of the tire 10 is increased, and the area to which electric power is supplied is widened.

On the other hand, when the control device 60 determines that the vehicle 2 is not in a position where the electric power can be supplied by wireless power supply when the internal pressure of the tire 10 is the second internal pressure, the control device 60 controls the compressor 50 to control the tire 10. The internal pressure of 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 composition)
The configuration of an example of a tire in the wireless power receiving system 1 according to the embodiment of the present invention will be described in detail.

Hereinafter, unless otherwise specified, the positional relationship of each element shall be measured in a reference state in which the tire is attached to the rim of the wheel, which is the applicable rim, the specified internal pressure is applied, and no load is applied. .. In addition, the width of the contact patch in contact with the road surface in the tire width direction is defined as the tire contact width when the tire is attached to the rim of the wheel, which is the applicable rim, the tire is filled with the specified internal pressure, and the maximum load is applied. The end of the contact patch in the tire width direction is called the contact patch.

In the present specification, the "applicable rim" is an industrial standard effective in the area where pneumatic tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) JATMA YEAR BOOK, and in Europe, ETRTO (ETRTO) The European Tire and Rim Technical Organization's STANDARDS MANUAL, and in the United States, TRA (The Tire and Rim Association, Inc.)' s YEAR BOOK, etc., or the size described or applied in the future. STANDARDS MANUAL refers to the Measuring Rim, and TRA's YEAR BOOK refers to the Design Rim), but in the case of a size not described in these industrial standards, it means a rim with a width corresponding to the bead width of the pneumatic tire. "Applicable rims" include sizes that may be included in the aforementioned industrial standards in the future in addition to current sizes. An example of a "future-described size" may be the size described as "FUTURE DEVELOPMENTS" in the ETRTO 2013 edition.

In the present specification, the "specified internal pressure" means the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in the applicable size and ply rating described in the above-mentioned industrial standards such as JATMA YEAR BOOK. In the case of a size not described in the above-mentioned industrial standards, it means the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle equipped with tires. Further, in the present specification, the "maximum load" means a load corresponding to the maximum load capacity of a tire of an applicable size described in the above-mentioned industrial standard, or a size not described in the above-mentioned industrial standard. Means the load corresponding to the maximum load capacity specified for each vehicle equipped with tires.

FIG. 2 shows a cross-sectional view in the tire width direction in which the tire 10 of the present embodiment is cut along the tire width direction. In the present specification, the tire width direction means a direction parallel to the rotation axis of the tire 10. In FIG. 2, the tire width direction is indicated by an arrow W. Further, the tire radial direction means a direction orthogonal to the rotation axis of the tire 10. In FIG. 2, the tire radial direction is indicated by an arrow R. In this embodiment, the tire 10 is described as having a configuration symmetrical with respect to the equatorial plane CL of the tire, but the present invention is not limited to this, and the tire 10 may have a configuration asymmetrical with respect to the equatorial plane CL of the tire.

In the present specification, the side close to the rotation axis of the tire 10 along the tire radial direction is referred to as "inside in the tire radial direction", and the side far from the rotation axis of the tire 10 along the tire radial direction is referred to as "outside in the tire radial direction". It is called. On the other hand, the side of the tire near the equatorial plane CL along the tire width direction is referred to as "inside in the tire width direction", and the side of the tire far from the equatorial plane CL along the tire width direction is referred to as "outside in the tire width direction".

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. The sidewall portion 12 extends between the tread portion 13 and the bead portion 11. The sidewall portion 12 is located outside the bead portion 11 in the tire radial direction. In the present specification, the tread portion 13 can be a portion between the above-mentioned grounding ends.

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 portion 11. As shown in a partially enlarged view in FIG. 2, the bead core 11A includes a plurality of bead wires 11c whose periphery is covered with rubber. The bead filler 11B is made of rubber or the like and is located outside the bead core 11A in the tire radial direction.

The tire 10 has a carcass 14. The carcass 14 extends toroidally between the pair of bead cores 11A to form the skeleton of the tire. The end side of the carcass 14 is locked to the bead core 11A. Specifically, the carcass 14 has a carcass main body portion 14A arranged between the bead cores 11A, and a carcass folding portion 14B that is folded around the bead core 11A from the inside in the tire width direction to the outside in the tire width direction. ing. In the present embodiment, the carcass 14 has a radial structure using a carcass cord, but the structure is not limited to this, and an arbitrary structure such as a bias structure can be used. The carcass 14 can be composed of one or more carcass layers (one in FIG. 2). As shown in a partially enlarged manner 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 on the outer side of the carcass 14 in the tread portion 13 in the tire radial direction. The belt 15 can be composed of, for example, one or more (two in FIG. 2) belt layers 15a and 15b laminated in the tire radial direction. As shown in a partially enlarged manner in FIG. 2, each of the belt layers 15a and 15b includes one or a plurality of belt cords 15c and a covering rubber 15r that covers the belt cords 15c.

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

The members constituting the tread portion 13 such as the belt 15 and the carcass 14, which are located outside the power receiving device 30 in the tire radial direction while the power receiving device 30 is housed in the tire / wheel assembly 3, are made of non-magnetic material. It may be formed. As a result, the magnetic field generated by the power transmission device 40 reaches the power reception device 30 due to the presence of a metal such as steel between the power reception device 30 and the power transmission device 40 while maintaining the strength of the tire 10 and the wheel 20. It is possible to prevent the power receiving device 30 from being attenuated by the time it is used, and to improve the power receiving efficiency of the power receiving device 30 in the wireless power supply.

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

In a state where the power receiving device 30 is housed in the tire / wheel assembly 3, the members constituting the bead portion 11 and the sidewall portion 12 and the like located outside the power receiving device 30 in the tire width direction are made of ferrite or the like. It may contain a magnetic material having a high magnetic permeability, for example, a ferromagnetic material. As a result, the magnetic field that reaches the power receiving device 30 from the power transmitting device 40 located outside the tire in the tire radial direction with respect to the tire 10 is a magnetic field of metal and other magnetic fields existing outside the bead portion 11 and the sidewall portion 12 in the tire width direction. It is possible to prevent attenuation due to the influence and, by extension, improve the power receiving efficiency of the power receiving device 30.

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

FIG. 3 shows a cross-sectional view in the wheel width direction in which the wheel 20 of the present embodiment is cut along the wheel width direction. In the present specification, the wheel width direction means a direction parallel to the rotation axis of the wheel 20. In FIG. 3, the wheel width direction is indicated by an arrow W. Further, the wheel radial direction means a direction orthogonal to the rotation axis of the wheel 20. In FIG. 3, the wheel radial direction is indicated by an arrow R. When the tire 10 is mounted on the wheel 20, the wheel width direction is parallel to the tire width direction described above, and the wheel radial direction is parallel to the tire radial direction described above.

In the present specification, the side close to the rotation axis of the wheel 20 along the wheel radial direction is referred to as "inside in the wheel radial direction", and the side far from the rotation axis of the wheel 20 along the wheel radial direction is referred to as "outside in the wheel radial direction". It is called. On the other hand, the side of the wheel near the equatorial plane CL along the wheel width direction is referred to as "inside in the wheel width direction", and the side of the wheel far from the equatorial plane CL along the wheel width direction is referred to as "outside in the wheel width direction".

As shown in FIG. 3, the wheel 20 has a cylindrical rim portion 21 and a disc 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 from the bead seat 24 outward in the wheel radial direction and outward in the wheel width direction in order to support the bead portion 11 of the tire 10 from the side surface. The well 25 has a concave shape inward in the radial direction of the wheel between the pair of bead seats 24 in order to facilitate the attachment / detachment of the tire. Therefore, the well 25 has an inclined surface that descends inward in the wheel width direction from the boundary with the bead sheet 24 to the bottom surface of the well 25. Further, the bead seat 24 is provided with a pair of humps 26 inside in the wheel width direction. The hump 26 projects outward in the wheel radial direction to prevent the tire bead from falling into the well 25.

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

The rim portion 21 of the wheel 20 is further provided with a valve 27 for filling the cavity of the tire 10 with a gas such as air when the tire 10 is mounted. The valve 27 can be made of, for example, the non-magnetic material described above. By making the valve 27 made of a non-magnetic material, when the power receiving device 30 is housed inside the wheel radial direction with respect to the rim portion 21 of the wheel 20, the power transmitting device located outside the wheel radial direction with respect to the rim portion 21. It is possible to prevent the magnetic field reaching the power receiving device 30 from 40 from being attenuated by the valve 27, and thus improve the power receiving efficiency of the power receiving device 30.

However, the rim portion 21 does not have to be entirely made of a non-magnetic material. For example, when the tire 10 is mounted, the inner part in the tire width direction of the tire 10 facing the tread portion 13 is formed of a non-magnetic material, and the outer part in the tire width direction is ferromagnetic such as metal. It may be made of a 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 contact surface of the tire 10. it can.

The disk portion 22 is provided with an annular mounting portion 22A forming an inner end portion in the radial direction and a plurality of spokes 22B extending outward in the radial direction of the wheel from the mounting portion 22A. The mounting portion 22A is a portion to be 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 radial outer end of the spoke 22B is integrally coupled to the end of the wheel radial inner surface of the rim portion 21.

The disk portion 22 may contain a magnetic material having a high magnetic permeability, for example, a ferromagnetic material, such as metal or ferrite. When the power receiving device 30 is housed inside the wheel radial direction with respect to the rim portion 21 of the wheel 20 due to the disk portion 22 containing the magnetic material, the power transmitting device 40 located outside the wheel radial direction with respect to the rim portion 21. It is possible to prevent the magnetic field reaching the power receiving device 30 from being attenuated by the influence of metal and other magnetic fields existing outside the disc portion 22 in the wheel width direction, and to improve the power receiving efficiency of the power receiving device 30. it can. On the other hand, the disk portion 22 can be made of the above-mentioned resin material. 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 contain a magnetic material having a high magnetic permeability, for example, a ferromagnetic material, such as metal or ferrite. When the power receiving device 30 is housed inside the wheel radial direction with respect to the rim portion 21 of the wheel 20 due to the wheel cover 28 containing the magnetic material, the power transmitting device 40 located outside the wheel radial direction with respect to the rim portion 21. It is possible to prevent the magnetic field reaching the power receiving device 30 from being attenuated by the influence of metal and other magnetic fields existing outside the wheel width direction from the wheel cover 28, and to improve the power receiving efficiency of the power receiving device 30. it can.

The wheel 20 is provided with a slip ring 29. The slip ring 29 can be provided, for example, on the mounting portion 22A of the wheel 20. The compressor 50 and the valve 27 provided in the vehicle 2 are connected via a slip ring 29 when they are airtably connected by a rubber tube or the like. As a result, when the tire 10 and the wheel 20 rotate in the tire circumferential direction, the valve 27 rotates and moves in the same manner, whereas the compressor 50 is installed at a position where it does not rotate, and the rubber tube It is possible to prevent such things from being twisted and damaged.

(Configuration of power receiving device)
Next, the configuration of an example of the power receiving device in the wireless power receiving system 1 according to the 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, for example, the hub 2A or the drive shaft 2B of the vehicle 2, so that the power receiving device 30 is attached to the hub 2A of the vehicle 2 and the wheel 20 is attached to the tire of the rim portion 21 of the wheel 20. It is housed inside in the radial direction. The power receiving coil 31 is configured 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 transmission coil 41 in a state where the tire / wheel assembly 3 is located above the power transmission device 40. It is arranged so as to be. As a result, when the tire 10 is located on the road surface above the power transmission coil 41, an electromotive force is generated by electromagnetic induction in the power receiving coil 31 based on the alternating magnetic field generated by the power transmission coil 41, and a current flows. The power receiving coil 31 included in the power receiving device 30 is wound around a core such as a ferrite core to form an annular shape as a whole, but is not limited to this, and can be used in an alternating magnetic field such as a coil spring or an air core coil. Based on this, any coil capable of generating an electromotive force can be used.

The power receiving device 30 may further include a power conversion circuit, a power storage unit, a measuring 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 the power storage unit or another in-vehicle device included in the vehicle 2 via a conductive wire or the like. The power storage unit stores the electric power generated in the power receiving coil 31. The power storage unit is, for example, a capacitor, but is not limited to this, and can be any power storage device such as a storage battery. When the power storage unit is a capacitor, charging / discharging can be performed in a shorter time than that of a storage battery. Therefore, the power storage unit, which is a capacitor, is advantageous in a situation where high responsiveness is required such that the power generated in the power receiving coil 31 is stored when the vehicle 2 travels on the power transmission device 40 provided on the road. is there. The measuring unit is, for example, a voltmeter or an ammeter, and by measuring the voltage or the current, the intensity of the electric power supplied by the power receiving device 30 from the outside can be calculated. In the present specification, the power intensity refers to an arbitrary numerical value representing the strength of power supplied wirelessly to the power receiving device 30, such as electric power, electric energy, 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 the power receiving device 30. The control unit may be a general-purpose processor such as a CPU (Central Processing Unit) that executes a program that defines a control procedure, or a dedicated processor that specializes in processing each function. The control unit may include any means used for controlling the power receiving device 30 such as a storage means for storing a program or the like and a communication means for communicating with an external electronic device by wire or wirelessly.

Although the power receiving device 30 has been described as being installed in the hub 2A of the vehicle 2 and being stored in the tire / wheel assembly 3, the installation position of the power receiving device 30 is not limited to the above-mentioned 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 in the wheel radial direction. According to these configurations, by changing the internal pressure of the tire 10 to a second internal pressure lower than the first internal pressure, the distance between the power transmission device 40 and the power receiving device 30 located outside the tire 10 in the tire radial direction. Can be brought closer, and the magnetic field reaching the power receiving device 30 can be increased. Further, by changing the internal pressure of the tire 10 to a second internal pressure lower than the first internal pressure, the contact area of the tire 10 is increased, and the area to which electric power is supplied is widened.

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

The compressor 50 fills the tire 10 with gas or discharges the gas from the tire 10 under the control of the control device 60. The compressor 50 is ventilatedly connected to the tire 10. The compressor 50 is breathably connected to the tire 10 by being connected to the valve 27 of the wheel 20 on which the tire 10 is mounted, for example, by a rubber tube or the like. The compressor 50 may further include a measuring unit for measuring the internal pressure of the tire 10. The measuring unit is, for example, a pressure gauge, but regardless of this, it can be any device such as a flow meter that can calculate the internal pressure of the tire 10. As a result, the compressor 50 can transmit the internal pressure of the tire 10 measured by the pressure gauge to the control device 60. Further, the compressor 50 is based on the control of the control device 60 described later so that the internal pressure of the tire 10 measured by the pressure gauge becomes the predetermined internal pressure when a predetermined internal pressure is specified by the control device 60. 10 can be filled with gas or gas can be released from the tire 10.

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

FIG. 4 is a functional block diagram schematically showing the configuration of the control device 60. 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 detachably installed.

The control device 60 includes a control unit 61, a storage unit 62, a communication unit 63, an output unit 64, and an input unit 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.

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

The storage unit 62 stores a process for controlling each function of the control device 60, information and a program used for the process. 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 as, for example, 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. Further, the storage unit 62 may be a volatile storage device or a non-volatile storage device. In the present embodiment, the storage unit 62 stores information and the like used for controlling the internal pressure of the tire 10, for example, as will be described in detail later.

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

The output unit 64 outputs information as sound, vibration, light, an image, or the like based on the control of the control unit 61. The output unit 64 may include at least one such as a speaker, an oscillator, a light, and a display device. 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 the power supplied to the power receiving device 30, information on the internal pressure of the tire 10, and the like. .. For example, when the power receiving device 30 is in a position where it can receive power wirelessly, the control unit 61 displays information on the output unit 64, which is a display device, and notifies the user that the 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 such as an input device such as a touch panel, a microphone that accepts voice input, and a camera that accepts gesture input. When the input unit 65 receives the input operation by the user, the input unit 65 transmits the input operation as electronic information to the control unit 61. The input operation may include, for example, an instruction to start a process of changing the internal pressure of the tire 10.

The control of the compressor 50 by the control device 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 unit 63 to the compressor 50. The control signal can be an arbitrary signal such as a signal that specifies the target value of the internal pressure of the tire 10 or a signal that specifies the operation of the compressor 50. The compressor 50 fills the tire 10 with air or discharges air from the tire 10 based on the control signal received from the control device 60. As a result, 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 by, for example, an arbitrary numerical value or numerical range within a range of air pressure suitable for the use of the tire 10, or a combination thereof, which is described in the above-mentioned industrial standards such as JATMA YEAR BOOK. it can. The predetermined internal pressure can be set, for example, by any numerical value or numerical range within the range specified in the "air pressure-load capacity correspondence table" of JATMA YEAR BOOK, or a combination thereof.

The predetermined internal pressure includes, at least, an internal pressure specified when the power receiving device 30 is in a position where it can receive power wirelessly, and an internal pressure specified in other cases. In the present specification, the internal pressure specified when power is not wirelessly supplied to the power receiving device 30 such as during normal driving is referred to as a first internal pressure, and a position where the power receiving device 30 can receive power wirelessly. The internal pressure specified in the case of is called the second internal pressure. The second internal pressure is set to a numerical value or a 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 depending on the traveling state of the vehicle 2, the road surface condition, and the like, such as the first internal pressure when the vehicle 2 is running and the first internal pressure when the vehicle 2 is stopped. Alternatively, a numerical range may be included. Further, the second internal pressure includes the electric power supplied by the traveling state, the road surface condition, and the wireless power supply of the vehicle 2, 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 that differ depending on the strength and the like may be included. 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.

The control device 60 determines whether or not the power receiving device 30 is in a position where it can receive power wirelessly.

For example, the control device 60 can determine whether or not the power receiving device 30 is in a position where it can receive power wirelessly, based on the information received from the GPS satellite. The control device 60 identifies the position of the vehicle 2 based on the information received from the GPS satellites. The control device 60 is located at a position where the power receiving device 30 can receive power wirelessly, for example, when the vehicle 2 is on a road or a parking lot where the power transmission device 40 is installed, as compared with map information or the like stored in advance. It can be determined that it is in.

Further, for example, the control device 60 can determine whether or not the power receiving device 30 is in a position where it can receive power wirelessly, based on the information indicating the position of the power transmitting device 40 that wirelessly supplies power to the power receiving device 30. it 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 a device installed in the vicinity of the power transmission device 40. For example, the control device 60 can determine that the power receiving device 30 is in a position where it can receive power wirelessly while receiving a predetermined signal. The predetermined signal may be a signal indicating a start position and an end position of the road on which the power transmission device 40 is installed. When the control device 60 receives the signal indicating the start position, it determines that the power receiving device 30 is in a position where it can receive power wirelessly, and when it receives the signal indicating the end position, the power receiving device 30 wirelessly receives power. It can be determined that the position is not possible.

Further, for example, the control device 60 can determine whether or not the power receiving device 30 is in a position where it can receive power wirelessly, based on the strength of the power supplied wirelessly to the power receiving device 30. The strength of electric power is, for example, electric power, but is not limited to this, and can be any numerical value indicating the intensity of electric power supplied to the power receiving device 30 by radio, such as electric energy, 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 on the strength of the power wirelessly supplied to the power receiving device 30. The control device 60 can determine, for example, that the power receiving device 30 is in a position where it can receive power wirelessly when the power receiving device 30 continuously receives power of a predetermined amount or more for a certain period of time.

When the control device 60 determines that the power receiving device 30 is in a position where it can receive power wirelessly when the internal pressure of the tire 10 is the first internal pressure, the control device 60 controls the compressor 50 to set the internal pressure of the tire 10 to the first internal pressure. Change to a second internal pressure that is lower than the internal pressure. As a result, the outer diameter of the tire 10 becomes smaller, and the distance between the power receiving device 30 and the power transmitting device 40 becomes closer, so that the transmission efficiency of wireless power supply can be improved. Further, by changing the internal pressure of the tire 10 to a second internal pressure lower than the first internal pressure, the contact area of the tire 10 is increased, and the area to which electric power is supplied is widened.

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

An example is shown in which the control device 60 automatically changes the internal pressure of the tire 10 based on the determination result of whether or not the power receiving device 30 is in a position where power can be received wirelessly, but this is not the case. For example, the control device 60 determines 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 of whether or not the power receiving device 30 is in a position where the power receiving device 30 can receive power wirelessly. May be changed. For example, when the power receiving device 30 is in a position where it can receive power wirelessly, the control device 60 displays information on the output unit 64, which is a display device, and notifies the user that the power receiving device 30 can receive power wirelessly. After that, when the input unit 65 receives an input from the user to change the internal pressure of the tire 10, 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 prevent the internal pressure of the tire 10 from changing at a timing not intended by the user, and to prevent a decrease in safety. Further, for example, when the user wants to prioritize the fuel efficiency performance of the tire 10 over the transmission efficiency of the wireless power supply, it can be determined that the internal pressure of the tire 10 is not changed, and the convenience of the wireless power receiving system 1 is improved.

The control device 60 can transmit a signal for changing the speed of the vehicle 2 when changing the internal pressure of the tire 10. For example, when automatic driving is performed in the vehicle 2, 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 is changed from the first internal pressure to the 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. Further, the control device 60 may increase the amount of electric power supplied to the power receiving device 30 by slowing down the speed of the vehicle 2 and increasing the time during which the power receiving device 30 is located above the power transmitting device 40. it can.

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

Step S101: The control device 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 in a position where it can receive power wirelessly. Specifically, the control device 60 is based on the information received from the GPS satellites, based on the information indicating the position of the power transmitting device 40, or based on the strength of the electric power supplied wirelessly to the power receiving device 30. It is possible to determine whether or not 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 not in a position where it can receive power wirelessly when the internal pressure of the tire 10 is the first internal pressure (step S102-No), the control device 60 sets the internal pressure of the tire 10 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 it can receive power 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 the second internal pressure lower than the first internal pressure.

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

Step S105: When the internal pressure of the tire 10 is the second internal pressure, the control device 60 controls the compressor 50 when it determines that the power receiving device 30 is not in a position where it can receive power wirelessly (step S104-No). , The internal pressure of the tire 10 is changed to the first internal pressure, and this process is completed.

Hereinafter, a modified example of the wireless power receiving system 1 according to the embodiment of the present invention will be described. FIG. 6 shows a schematic view schematically showing a modified example of the wireless power receiving system 1 according to the embodiment of the present invention using a cross section in the tire width direction. In the modified example of the wireless power receiving system 1, unlike the wireless power receiving system 1 shown in FIG. 1, the tire / wheel assembly 3 in which the tire 10 is mounted on the rim portion 21 of the wheel 20 has the power receiving device 30, the compressor 50, and the like. And the control device 60 is 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 members and parts common to the wireless power receiving system 1 shown in FIG. 1 are designated by the same reference numerals, and their description will be omitted.

The in-wheel motor 4 is integrated with the hub and installed in the accommodating 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 partially located outside the accommodating portion of the wheel 20 in the tire width direction in a state of being attached to the wheel 20. The power receiving device 30 can be 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 in-wheel motor 4 with DC power. it can.

While 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 is driven so that the ground contact surface of the tire 10 passes over the power transmission device 40 provided on the road or the like, or the vehicle 2 is stopped so as to be located on the power transmission device 40. Then, the power receiving device 30 can supply the power received wirelessly from the power transmission device 40 to the in-wheel motor 4. 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 in a position where it can receive power wirelessly. When the control device 60 determines that the power receiving device 30 is in a position where it can receive power wirelessly when the internal pressure of the tire 10 is the first internal pressure, the control device 60 controls the compressor 50 to set the internal pressure of the tire 10 to the first internal pressure. Change to a second internal pressure that is lower than the internal pressure. As a result, the outer diameter of the tire 10 becomes smaller, and the distance between the power receiving device 30 and the power transmitting device 40 becomes closer, so that the transmission efficiency of wireless power supply can be improved. On the other hand, when the control device 60 determines that the power receiving device 30 is not in a position where power can be received by wireless power supply when the internal pressure of the tire 10 is the second internal pressure, the control device 60 controls the compressor 50 to control the internal pressure of the tire 10. Is changed 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 of the tire 10 to the outer diameter OD is 0.26 or less. Is preferable. 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 the relational expressions (1) and 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, the air resistance is reduced, and the cross-sectional width is narrow. Therefore, it is possible to secure a vehicle space, and in particular, it is possible to secure an installation space for drive parts near the inside of the tire 10 mounted on the vehicle.

Further, by satisfying the above 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, the rolling resistance is reduced, and the tire 10 Since the wheel shaft becomes taller due to the larger diameter and the space under the floor is expanded, it is possible to secure a space such as a trunk of the vehicle 2 and a space for installing drive parts.

As described above, by satisfying the above ratio SW / OD or the relational expression (1), it is possible to achieve low fuel consumption with respect to the supplied electric energy, and it is also possible to secure a large vehicle space. ..

In the present invention, in the tire 10, the cross-sectional width SW (mm) and the outer diameter OD (mm) of the tire 10 have 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, the air resistance is reduced, and the vehicle space is reduced by the narrow cross-sectional width. It can be secured, and in particular, a space for installing drive parts can be secured in the vicinity of the inside of the tire 10 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, the rolling resistance is reduced, and the wheel is increased by increasing the diameter of the tire 10. Since the shaft is raised and the space under the floor is expanded, it is possible to secure a space for the trunk of the vehicle 2 and a space for installing drive parts.

As described above, by satisfying the above relational expression (2), it is possible to achieve low fuel consumption with respect to the supplied electric energy, and it is also possible 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 / Alternatively, it is preferable to satisfy the relational expression (2).

In each of the above examples, the tire 10 is preferably used at an internal pressure of 250 kPa or more. In this case, in particular, the tire 10 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 the relational expression (2). ) Is satisfied. As a result, both the rolling resistance value of the tire and the weight of the tire can be reduced. Therefore, both power feeding efficiency and fuel efficiency can be suitably achieved.

In each of the above examples, in the tire 10, the cross-sectional area of the bead filler 11B in the tire width direction (cross-sectional area of the bead filler 11B in the cross section shown in FIG. 2) is the cross-sectional area of the bead core 11A in the tire width direction (cross-sectional area of the bead core 11A in the cross section shown in FIG. 2). It is preferable that the cross-sectional area of the tire is 1 times or more and 8 times or less. As a result, both power supply efficiency and fuel efficiency can be suitably achieved.
In the case of a sandwiched bead core structure in which the carcass is held from the inside and the outside in the tire width direction, the total area of the bead cores inside and outside the width direction of the carcass is defined as 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, the volume of the bead filler 11B, which is a high-rigidity member, can be reduced, the longitudinal spring coefficient of the tire can be reduced, and the riding comfort can be improved. Further, the weight of the bead filler 11B can be reduced to reduce the weight of the tire 10, and therefore the rolling resistance value of the tire 10 is further reduced.
In particular, in a narrow-width / large-diameter tire that satisfies the above relational expression (1) or (2), the tension rigidity of the belt is high and the tension rigidity of the tire side portion is low as compared with the belt. In addition, the effect of reducing the longitudinal spring coefficient by setting the cross-sectional area of the bead filler 11B in the tire width direction within a predetermined range becomes very high.
Here, if the cross-sectional area of the bead filler in the tire width direction is more than 8 times the cross-sectional area of the bead core in the tire width direction, the volume of the bead filler, which is a high-rigidity member, becomes large, and the longitudinal spring coefficient of the tire is not sufficiently reduced. Ride quality may be reduced.
On the other hand, if the cross-sectional area in the tire width direction of the bead filler is less than 1 times the cross-sectional area in the tire width direction of the bead core, the rigidity of the bead portion is significantly reduced and the lateral spring coefficient is excessively reduced to ensure steering stability. It may not be possible.

In each of the above examples, the tire 10 has a width in the tire width direction of the bead filler 11B at the center position in the tire radial direction as "BFW" (see FIG. 2) and a maximum width of the bead core 11A in the tire width direction as "BDW" (FIG. 2). 2)
0.1 ≤ BFW / BDW ≤ 0.6
It is preferable to satisfy. As a result, both power supply efficiency and fuel efficiency can be suitably achieved.
By setting the ratio BFW / BDW to 0.6 or less, the volume of the bead filler 11B is reduced while maintaining the height of the bead filler, so that the rigidity in the tire rotation direction is secured and the vertical spring coefficient is reduced. The ride quality 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, the rigidity of the bead portion 11 can be ensured, the lateral spring constant can be maintained, and the steering stability can be further ensured.

In each of the above examples, the height of the bead filler 11B in the tire radial direction is "BFH" (see FIG. 2), and the tire cross-sectional height (section height) of the tire 10 is "SH" (see FIG. 2). When
0.1 ≤ BFH / SH ≤ 0.5
It is preferable to satisfy. As a result, both power supply efficiency and fuel efficiency can be suitably 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, the vertical spring constant of the tire 10 is effectively reduced, and the riding comfort is improved. Can be made to.
On the other hand, by setting the ratio BFH / SH to 0.1 or more, the rigidity of the bead portion 11 can be ensured, the lateral spring constant can be maintained, and the steering stability can be further ensured.
Here, the tire cross-sectional height SH is the difference between the outer diameter and the rim diameter of the tire 10 in a no-load state when the tire 10 is incorporated in the rim and the internal pressure specified for each vehicle to which the tire is mounted is applied. It shall mean 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 suitably achieved.

In each of the above examples, the tire 10 has a gauge Ts (see FIG. 2) of the sidewall portion 12 in the maximum tire width portion and a bead width Tb (in the tire width direction of the bead portion 11) at the center position in the tire radial direction of the bead core 11A. It is preferable that the ratio Ts / Tb with the width (see FIG. 2) is 15% or more and 60% or less. As a result, both power supply efficiency and fuel efficiency can be suitably achieved.
The "maximum tire width portion" refers to the maximum width position in the cross section in the tire width direction when the tire 10 is incorporated in the rim and is in a no-load state.
The 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 to the above range, it is possible to appropriately reduce the rigidity in the maximum width portion of the tire having a large bending deformation under a tire load, reduce the longitudinal spring coefficient, and improve the riding comfort. ..
That is, when the ratio Ts / Tb exceeds 60%, the gauge Ts (see FIG. 2) of the sidewall portion 12 in the maximum tire width portion becomes large, the rigidity of the sidewall portion 12 becomes high, and the longitudinal spring coefficient becomes high. It may be expensive. On the other hand, if the ratio Ts / Tb is less than 15%, the lateral spring constant may be too low 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 maximum tire width portion of 1.5 mm or more. As a result, both power supply efficiency and fuel efficiency can be suitably achieved.
By setting the thickness to 1.5 mm or more, it is possible to maintain an appropriate rigidity in the maximum tire width portion, suppress a decrease in the lateral spring coefficient, and further secure steering stability.

In each of the above examples, the tire 10 preferably has a bead core 11A having a diameter Tbc (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 suitably achieved.
By making it 3 mm or more, it is possible to realize weight reduction while ensuring bending rigidity and torsional rigidity on the flange 23 of the rim (see FIG. 3), while by making it 16 mm or less, the weight is increased. It is possible to secure steering stability while suppressing.
When the bead core 11A is divided into a plurality of small bead cores by the carcass 14, the distance between the innermost end and the outermost end in the width direction of all the small bead cores may be Tbc.

In each of the above examples, the tire 10 preferably has a ground contact area of 8000 mm ² or more when a maximum load specified for each vehicle to 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 the tire weight, and it is possible to preferably achieve both power feeding efficiency and fuel efficiency. In addition, the tire axial force can be secured to improve the stability and safety of the vehicle.

In each of the above examples, the tire 10 preferably has a belt cord 15c having a Young's modulus of 40,000 MPa or more. 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 a high internal pressure can be secured. In addition, both power supply efficiency and fuel efficiency can be suitably achieved.

In each of the above examples, the tire 10 preferably has an inner liner 16 having a thickness of 0.6 mm or more. This makes it possible to suppress air leakage in a high internal pressure state. In addition, both power supply efficiency and fuel efficiency can be suitably achieved.

In each of the above examples, the tire 10 has a ratio Ts / Tc of 4 or more between the gauge Ts of the sidewall portion 12 in the maximum tire width portion (see FIG. 2) and the diameter Tc of the carcass cord 14c (see FIG. 2). 12 or less is preferable. As a result, both power supply efficiency and fuel efficiency can be suitably achieved.
By setting the ratio Ts / Tc to the above range, it is possible to appropriately reduce the rigidity in the maximum width portion of the tire having a large bending deformation under a tire load, reduce the longitudinal spring coefficient, and improve the riding comfort. ..
That is, when the ratio Ts / Tc exceeds 12, the gauge Ts (see FIG. 2) of the sidewall portion 12 in the maximum tire width portion becomes large, the rigidity of this portion becomes high, and the longitudinal spring coefficient becomes high. There is a risk that it will end up. On the other hand, if the ratio Ts / Tc is less than 4, the lateral spring constant may be too low to ensure steering stability.

In each of the above examples, the tire 10 has a distance Ta and a diameter of the carcass cord 14c, where Ta (see FIG. 2) is the distance in the tire width direction from the surface of the carcass cord 14c to the outer surface of the tire in the maximum width portion of the tire. The ratio Ta / Tc with 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 suitably achieved.
By setting the ratio Ta / Tc to 8 or less, the gauge Ts (see FIG. 2) of the sidewall portion 12 in the maximum tire width portion is reduced, the rigidity of the sidewall portion 12 is reduced, and the longitudinal spring coefficient is increased. It can be reduced and the riding comfort can be further improved. On the other hand, by setting the ratio Ta / Tc to 2 or more, the lateral spring constant can be secured and the steering stability can be further ensured.
In addition, "Ta" (see FIG. 2) means 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 in the tire maximum width portion.
That is, when the carcass folded portion 14B extends radially outward from the maximum tire width portion, the distance in the tire width direction from the surface of the carcass cord 14c of the portion forming the carcass folded portion 14B to the outer surface of the tire is set to Ta. ..

In each of the above examples, the tire 10 preferably has a carcass cord 14c having a diameter Tc (see FIG. 2) of 0.2 mm or more and 1.2 mm or less. As a result, both power supply efficiency and fuel efficiency can be suitably achieved.
By setting it to 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 reduced to reduce the vertical spring coefficient, while by setting it to 0.2 mm or more, the gauge Ts can be reduced. The gauge Ts of the sidewall portion 12 with respect to the diameter Tc of the carcass cord 14c can be secured, and the lateral spring constant can be increased to ensure steering stability.

As described above, the wireless power receiving system 1 according to the embodiment of the present invention is housed in the tire / wheel assembly 3 composed of the tire 10 and the wheel 20, and the tire / wheel assembly 3, and is more tire than the tire 10. It includes a power receiving device 30 that receives power wirelessly supplied from the outside in the radial direction, a compressor 50 that is breathably 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 in a position where it can receive power wirelessly, and when the internal pressure of the tire 10 is the first internal pressure, the power receiving device 30 is in a position where it can receive power wirelessly. When the determination is made, the internal pressure of the tire 10 is changed to the 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 where the power can be received wirelessly. If it is determined, 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 the power receiving device 30 is in a position where the power receiving device 30 can receive power wirelessly. As a result, when the power receiving device 30 is in a position where power can be received by wireless power supply, the internal pressure of the tire 10 is lowered to bring the power receiving device 30 and the power transmitting device 40 closer to each other, thereby improving the transmission efficiency of wireless power feeding. When the power receiving device 30 is not in a position where power can be received by wireless power supply, the internal pressure of the tire 10 can be increased to reduce the rolling resistance coefficient of the tire 10 and improve the fuel efficiency of the tire 10. Therefore, the power receiving device 30 housed in the tire / wheel assembly 3 can efficiently receive the power wirelessly supplied from the power transmission device 40 provided on the road or the like, and the power receiving efficiency in the wireless power supply is improved. To do.

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

In the wireless power receiving system 1 according to the embodiment of the present invention, the control device 60 can wirelessly receive power from the power receiving device 30 based on the 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 or not 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 higher accuracy whether or not the power receiving device 30 is in a position where power can be received wirelessly.

In the wireless power receiving system 1 according to the embodiment of the present invention, whether or not the control device 60 is in a position where the power receiving device 30 can receive power wirelessly based on the strength of the power supplied wirelessly to the power receiving device 30. It is preferable to determine. According to such a configuration, since the determination is made based on the strength of the electric power actually received by the power receiving device 30, it is possible to determine with higher accuracy whether or not the power receiving device 30 is in a position where it can receive power wirelessly.

In the wireless power receiving system 1 according to the embodiment of the present invention, the tire 10 includes a tread portion 13 made of a non-magnetic material, and the wheel 20 has a rim portion 21 formed of at least a part of a non-magnetic material. It is preferable that the power receiving device 30 accommodates the power receiving device 30 inside the rim portion 21 of the wheel 20 in the tire radial direction. According to this configuration, in the case of a device that generates a magnetic field of the power transmission device 40, the tire 10 is reached by the time the magnetic field generated by the power transmission device 40 reaches the power receiving device 30 housed in the tire / wheel assembly 3. It is possible to reduce the damping through the tread portion 13 and the rim portion 21 of the wheel 20.

In the wireless power receiving system 1 according to the embodiment of the present invention, the wheel 20 preferably includes a slip ring 29 for breathably connecting the compressor 50 to the tire 10. According to this configuration, while the tire 10 rotates in the tire circumferential direction, when the compressor 50 is installed at a position where it does not rotate, the ventilation path between the tire 10 and the compressor 50 is twisted and damaged. Can be prevented.

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

The control method of the wireless power receiving system 1 according to the embodiment of the present invention includes a step 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, and a tire 10 by the control device 60. When it is determined 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, the step of changing the internal pressure of the tire 10 to the second internal pressure lower than the first internal pressure, and When the control device 60 determines that the internal pressure of the tire 10 is the second internal pressure and the power receiving device 30 is not in a position where power can be received wirelessly, the step of changing the internal pressure of the tire 10 to the first internal pressure, and 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 the power receiving device 30 is in 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 the power wirelessly supplied from the power transmission device 40 provided on the road or the like, and the power receiving efficiency in the wireless power supply can be improved. improves.

The tire / wheel assembly 3 according to an embodiment of the present invention is a tire / wheel assembly 3 composed of a tire 10 and a wheel 20, and is housed in the tire / wheel assembly 3 in the tire radial direction with respect to the tire 10. It includes a power receiving device 30 that receives power wirelessly supplied from the outside, a compressor 50 that is breathably 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 in a position where it can receive power wirelessly, and when the internal pressure of the tire 10 is the first internal pressure, the power receiving device 30 is in a position where it can receive power wirelessly. When the determination is made, the internal pressure of the tire 10 is changed to the 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 where the power can be received wirelessly. If it is determined, 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 the power receiving device 30 is in 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 the power wirelessly supplied from the power transmission device 40 provided on the road or the like, and the power receiving efficiency in the wireless power supply can be improved. improves.

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

For example, in the present invention, an example is shown in which the power receiving device 30 is wirelessly supplied with power from the power transmitting device 40 by an electromagnetic induction method, but the present invention is not limited to this. 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.

Further, for example, in the present invention, the vehicle 2 has been described as being an automobile, but this is not the case. In addition to automobiles such as passenger cars, trucks, buses, and two-wheeled vehicles, vehicle 2 can be moved by wheels and tires such as agricultural vehicles such as tractors, construction or construction vehicles such as dump trucks, bicycles, and wheelchairs. It may be any vehicle.

Further, for example, in the present invention, the tire 10 has been described as being filled with air, but the present invention is not limited to this. 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 including not only gas but also liquid, gel-like substance, powder or granular material and the like.

Further, for example, in the present invention, the tire 10 has been described as being a tubeless tire provided with an inner liner 16, but this is not the case. For example, the tire 10 may be a tube type tire including a tube. Further, for example, the tire 10 may be an airless tire which is formed in whole or in part by the above-mentioned resin material and 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 part, 11A: Bead core, 11B: Bead filler, 11c: Bead wire, 12 : Side wall part, 13: Tread part, 14: Carcus, 14A: Carcus body part, 14B: Carcus folded part, 14c: Carcus cord, 14r: Covered rubber, 15: Belt, 15a, 15b: Belt layer, 15c: Belt Cord, 15r: Coated rubber, 16: Inner liner, 20: Wheel, 21: Rim part, 22: Disc part, 22A: Mounting part, 22B: Spoke, 23: Flange, 24: Bead sheet, 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: Transmission device, 41: 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 consisting of tires and wheels,
A power receiving device housed in the tire / wheel assembly and receiving electric power wirelessly supplied from outside the tire in the radial direction of the tire.
With a compressor that is breathably connected to the tire,
A control device that controls the compressor to change the internal pressure of the tire,
With
The control device is
It is determined whether or not the power receiving device is in a position where it can receive power wirelessly.
When the internal pressure of the tire is the first internal pressure and it is determined that the power receiving device is in a position where it can receive power wirelessly, the internal pressure of the tire is changed to the second internal pressure lower than the first internal pressure. ,
A wireless power receiving system that changes the internal pressure of a tire to the first internal pressure when it is determined that the power receiving device is not in a position where it can receive power wirelessly when the internal pressure of the tire is the second internal pressure. The wireless power receiving system according to claim 1, wherein the control device determines whether or not the power receiving device is in a position where it can receive wireless power based on information received from GPS satellites. The first aspect of claim 1, wherein the control device determines whether or not the power receiving device is in a position where it can receive power wirelessly, based on information indicating the position of a power transmitting device that wirelessly supplies power to the power receiving device. Wireless power receiving system. The wireless power receiving system according to claim 1, wherein the control device determines whether or not the power receiving device is in a position where it can receive power wirelessly, based on the intensity of electric power supplied to the power receiving device wirelessly. The tire has a tread portion made of a non-magnetic material.
The wheel has a rim portion that is 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. The wireless power receiving system according to any one of claims 1 to 5, wherein the wheel includes a slip ring for breathably connecting the compressor to the tire. The wireless power receiving system according to any one of claims 1 to 6, wherein the power receiving device receives electric power supplied by an electromagnetic induction method. The control method for a 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 it can receive power wirelessly by the control device, and
When the control device determines that the internal pressure of the tire is the first internal pressure and the power receiving device is in a position where the electric power can be received wirelessly, the internal pressure of the tire is lower than the first internal pressure. Steps to change to the internal pressure of
When the control device determines that the internal pressure of the tire is the second internal pressure and the power receiving device is not in a position where it can receive power wirelessly, the step of changing the internal pressure of the tire to the first internal pressure. When,
How to control a wireless power receiving system, including. A tire-wheel assembly consisting of tires and wheels.
A power receiving device housed in the tire / wheel assembly and receiving electric power wirelessly supplied from outside the tire in the radial direction of the tire.
With a compressor that is breathably connected to the tire,
A control device that controls the compressor to change the internal pressure of the tire,
With
The control device is
It is determined whether or not the power receiving device is in a position where it can receive power wirelessly.
When the internal pressure of the tire is the first internal pressure and it is determined that the power receiving device is in a position where it can receive power wirelessly, the internal pressure of the tire is changed to the second internal pressure lower than the first internal pressure. ,
When the internal pressure of the tire is the second internal pressure, if 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 first internal pressure of the tire / wheel assembly. ..

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