Power supply unit, sensor module and tire equipped therewith, and wireless power supply system

Abstract

The present invention provides a power supply unit, a sensor module, a tire equipped therewith, and a wireless power supply system, which can receive and store power from a power transmission device on the outside of the tire, and which also improves impact resistance. [Solution] The unit body 11 comprises a power receiving unit 12 that receives power and a power storage unit 13 that stores the received power, and at least a part of this unit body 11 is housed in an elastic body 30, and the modulus M when the elastic body 30 is stretched to 50% 50 The pressure is in the range of 0.3 MPa to 10 MPa.

Description

[Technical Field]

[0001] The present invention relates to a power supply unit, a sensor module, a tire equipped therewith, and a wireless power supply system, and more particularly to a power supply unit, a sensor module, a tire equipped therewith, and a wireless power supply system that can receive and store power from a power transmission device on the outside of the tire and improve impact resistance. [Background technology]

[0002] Various sensors are installed inside the tire cavity to acquire internal tire information such as internal pressure and temperature (see, for example, Patent Documents 1 and 2). Such sensors require a large power supply to continuously acquire advanced tire information. For example, if batteries are used as the power source for the sensors, there is a problem in that power cannot be supplied continuously over a long period of time. Furthermore, when used over a long period, the sensors may be damaged by the tire's operating environment, so adequate protection of the sensors is required. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 6272225 [Patent Document 2] Special Publication No. 2016-505438 [Overview of the project] [Problems that the invention aims to solve]

[0004] The object of the present invention is to provide a power supply unit, a sensor module, a tire equipped therewith, and a wireless power supply system that can receive and store power from a power transmission device on the outside of the tire, and that can improve impact resistance. [Means for solving the problem]

[0005] To achieve the above objective, the power supply unit of the present invention comprises a unit body integrally housing a power receiving section for receiving power and a power storage section for storing the received power, wherein at least a part of the unit body is housed in an elastic body, and the modulus M when the elastic body is stretched to 50% 50 It is characterized by having a pressure range of 0.3 MPa to 10 MPa.

[0006] Furthermore, the sensor module of the present invention comprises a module body that integrally houses an electronic component including a power receiving unit for receiving power, a power storage unit for storing the received power, and a sensor element for detecting tire information, and at least a part of this module body is housed in an elastic body, and the modulus M when the elastic body is stretched to 50% 50 It is characterized by having a pressure range of 0.3 MPa to 10 MPa.

[0007] Further, the wireless power supply system of the present invention includes a tire provided with the above-described power supply unit or sensor module on the inner surface of the tire, a power receiving circuit unit disposed as a power receiving unit of the power supply unit or the power receiving unit of the sensor module, and configured to receive power wirelessly, and a power supply device including a power supply circuit unit that wirelessly supplies power to the power receiving unit. The power supply circuit unit has at least a power supply coil that generates a magnetic flux, and supplies power to generate a magnetic flux in the power supply coil. The power receiving circuit unit has at least a power receiving coil that receives the magnetic flux emitted from the power supply coil, and recovers the energy generated in the power receiving coil by electromagnetic induction. The power supply circuit unit includes a resonance capacitor on the power supply side that forms a parallel resonance circuit so as to resonate at a predetermined resonance period in combination with the power supply coil, a switch circuit that realizes a switch-on state in which a drive current flows through the power supply coil and a switch-off state in which the drive current is cut off, and a control circuit that inputs a drive pulse signal for controlling on and off of the switch circuit and adjusts the timing of inputting the drive pulse signal. The power receiving circuit unit has a resonance capacitor on the power receiving side that forms a resonance circuit so as to resonate at a predetermined resonance period in combination with the power receiving coil. When the power supply device is installed at a location close to a part of the tire and the power receiving unit is located within the power supply range of the power supply device, the capacitance of the resonance capacitor on the power supply side or the inductance of the power supply coil is appropriately finely adjusted with respect to the distance between the power receiving unit and the power supply device, and the resonance period of the power supply device is finely adjusted at the timing of inputting the drive pulse signal, and further includes a frequency adjustment circuit that appropriately controls the distance between the power receiving unit and the power supply device.

Advantages of the Invention

[0008] In the power supply unit of the present invention, since the unit body integrally houses a power receiving unit that receives power and a power storage unit that stores the received power, the power receiving unit can receive power supplied from a power transmission device outside the tire and store the received power in the power storage unit. As a result, it is possible to use the unit for a long time without replacing the battery as in the prior art. Further, at least a part of the unit body is housed in an elastic body, and the modulus M when the elastic body is stretched by 50% 50 is in the range of 0.3 MPa to 10 MPa. Therefore, when the elastic body is deformed, it is possible to appropriately ensure the force to maintain the original shape or the force to return to the original shape without breaking, and it is possible to relieve or absorb the impact, so that the power supply unit can be sufficiently protected. Thereby, the impact resistance of the power supply unit can be improved.

[0009] In the power supply unit of the present invention, it is preferable that the inner surface area Ea [mm 2 of the elastic body and the outer surface area Pa [mm 2 of the unit body satisfy the relationship of 0.4 ≦ Ea / Pa. Thereby, it is possible to prevent damage to the power supply unit and detachment from the elastic body.

[0010] In the sensor module of the present invention, since the module body integrally houses a power receiving unit that receives power, a power storage unit that stores the received power, and an electronic component including a sensor element that detects tire information, the power receiving unit can receive power supplied from a power transmission device outside the tire and store the received power in the power storage unit. As a result, it is possible to use the module for a long time without replacing the battery as in the prior art. Further, at least a part of the module body is housed in an elastic body, and the modulus M when the elastic body is stretched by 50% 50 is in the range of 0.3 MPa to 10 MPa. Therefore, when the elastic body is deformed, it is possible to appropriately ensure the force to maintain the original shape or the force to return to the original shape without breaking, and it is possible to relieve or absorb the impact, so that the sensor module can be sufficiently protected. Thereby, the impact resistance of the sensor module can be improved.

[0011] In the sensor module of the present invention, the inner surface area Ea [mm 2 of the elastic body and the outer surface area Ma [mm 2 of the module body preferably satisfy the relationship of 0.5 ≦ Ea / Ma. Thereby, breakage of the sensor module and dropping off from the elastic body can be prevented.

[0012] In the power supply unit or sensor module of the present invention, the elongation at break EB [%] of the elastic body at 20°C and the modulus M 100 [MPa] at 100% elongation of the elastic body preferably satisfy the relationship of the following formula (1). Thereby, the elongation at break at normal temperature and the modulus at high temperature in the elastic body can be appropriately balanced, and the workability of housing the power supply unit or sensor module in the elastic body and the high-speed durability can be made compatible. 1000 ≧ 275 × M 100 -EB ···(1)

[0013] In the tire of the present invention, a tire having the above power supply unit or sensor module on the inner surface of the tire, a reinforcing layer including a plurality of steel cords is disposed, and the sensor module is disposed in a region of the inner surface of the tire corresponding to the disposition region of the reinforcing layer. The ratio of the area of the portion excluding the steel cords to the area of the reinforcing layer in the front view of the reinforcing layer is preferably in the range of 5% to 60%. While ensuring the effects as a reinforcing layer (for example, course holding property, cut resistance, and turning performance), the power receiving function of the power receiving unit and the power storage function of the power storage unit can be sufficiently exhibited.

[0014] In the tire of the present invention, a tire having the above power supply unit or sensor module, and the power receiving unit is preferably disposed parallel to the inner surface of the tire. By disposing in this way, it is suitable when the power receiving unit receives power supplied from a power transmission device outside the tire.

[0015] In this invention, the modulus at 50% elongation is determined by taking a predetermined rubber test piece (e.g., dumbbell-shaped type 7) from an elastic body, and performing a tensile test on this rubber test piece at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and determining the tensile stress (MPa:M) at 50% elongation. 50 This value is confirmed by measuring it at room temperature.

[0016] The tire of the present invention is preferably a pneumatic tire, but may also be a non-pneumatic tire. In the case of a pneumatic tire, the inside can be filled with air, an inert gas such as nitrogen, or other gases. [Brief explanation of the drawing]

[0017] [Figure 1] (a) and (b) show an example of a power supply unit according to an embodiment of the present invention, where (a) is a perspective view of the power supply unit and (b) is a cross-sectional view of the power supply unit. [Figure 2] (a) and (b) show an example of a sensor module according to an embodiment of the present invention, where (a) is a perspective view of the sensor module and (b) is a cross-sectional view of the sensor module. [Figure 3] This is a meridian cross-sectional view showing an example of a pneumatic tire according to an embodiment of the present invention. [Figure 4] Figure 3 is a plan view showing the belt layer arranged in a pneumatic tire. [Figure 5] This is a basic circuit diagram of a wireless power supply system according to an embodiment of the present invention. [Figure 6] This is a basic waveform diagram of the power supply device according to the present invention (when SW2 = OFF). [Figure 7] This is a basic waveform diagram of the power supply device according to the present invention (when SW2 = ON). [Figure 8] This is a configuration diagram of a wireless power supply system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0018] The configuration of the present invention will be described in detail below with reference to the attached drawings. Figures 1(a) and 1(b) show a power supply unit consisting of an embodiment of the present invention.

[0019] As shown in Figures 1(a) and 1(b), the power supply unit 10 comprises a unit body 11 (housing) that integrally houses a power receiving unit 12 that receives power supplied from a power transmission device (power supply device) on the outside of the tire, and a power storage unit 13 that stores the received power. The unit body 11 has a contact surface 11x that contacts the inner surface of the tire. That is, the contact surface 11x is the surface that contacts the bottom surface of the elastic body 30, which will be described later. This contact surface 11x may be bonded to the elastic body 30, but if it is bonded, it will be difficult to replace the power supply unit 10.

[0020] The power receiving unit 12 receives power wirelessly from a power transmission device (power supply device) located on the outside of the tire. Electromagnetic induction can be used as the wireless power supply method. The power receiving unit 12 can be composed of, for example, a coil, a capacitor, and a rectifier circuit.

[0021] The power storage unit 13 stores the power received by the power receiving unit 12. The power storage unit 13 can utilize a secondary battery. If the power storage unit 13 is connected to, for example, a sensor attached to the inside of a tire, it can supply power to that sensor.

[0022] These power receiving unit 12 and power storage unit 13 are electrically connected to each other. In particular, it is preferable that the power receiving unit 12 and power storage unit 13 are stacked in that order from the inner surface side of the tire.

[0023] In such a power supply unit 10, at least a portion of the unit body 11 is housed in an elastic body 30. That is, the elastic body 30 is a housing for protecting the power supply unit 10. The elastic body 30 comprises a flat plate-shaped base portion 31 fixed to the inner surface of the tire and a cylindrical side wall portion 32 protruding from the base portion 31.

[0024] The elastic body 30 can be made of, for example, rubber. The modulus M of the elastic body 30 when stretched to 50% 50 The modulus M is in the range of 0.3 MPa to 10 MPa. 50 The pressure is preferably in the range of 0.5 MPa to 8.0 MPa, and more preferably in the range of 0.5 MPa to 4.0 MPa.

[0025] The power supply unit 10 described above includes a unit body 11 that integrally houses a power receiving unit 12 for receiving power and a power storage unit 13 for storing the received power. Therefore, the power receiving unit 12 can receive power supplied from a power transmission device on the outside of the tire, and the received power can be stored in the power storage unit 13. This eliminates the need to replace batteries as in conventional systems, enabling long-term use. Furthermore, at least a portion of the unit body 11 is housed in an elastic material, and the modulus M of the elastic material 30 when stretched to 50% 50 Since the pressure range is between 0.3 MPa and 10 MPa, when the elastic body 30 is deformed, it can adequately maintain its original shape or return to its original state without breaking, thereby mitigating or absorbing the impact and adequately protecting the power supply unit 10. This improves the impact resistance of the power supply unit 10.

[0026] Here, the modulus M of the elastic body 30 50 If the modulus M of the elastic body 30 is less than 0.3 MPa, the force that tries to maintain the original shape of the elastic body 30 becomes weak, and the effect of improving impact resistance cannot be fully obtained. Conversely, if the modulus M of the elastic body 30 50 If the pressure exceeds 10 MPa, the flexibility of the elastic body 30 decreases, making it difficult to follow the deformation that occurs when the tire makes contact with the ground during rotation. As a result, the cushioning ability of the elastic body 30 decreases, and the impact resistance of the power supply unit 10 tends to decrease.

[0027] In the above power supply unit, the internal surface area Ea[mm²] of the elastic body 30 2 ] and the outer surface area Pa[mm] of the unit body 11 2The ratio Ea / Pa preferably satisfies the relationship 0.4 ≤ Ea / Pa, more preferably 0.5 ≤ Ea / Pa, and most preferably 0.6 ≤ Ea / Pa. As the ratio Ea / Pa increases, the contact area between the elastic body 30 and the power supply unit 10 increases, and the height of the elastic body 30 (side wall portion 32) increases. The upper limit of the ratio Ea / Pa is preferably 2.0 or less, may be 1.5 or less, or may be 1.0 or less. In addition, for example, a configuration in which a second power supply unit (not shown) is stacked on the unit body 11 can be used, in which case the outer surface area Pa of the unit body 11 does not include the outer surface area of ​​the stacked second power supply unit. By setting the ratio Ea / Pa appropriately in this way, damage to the power supply unit 10 and detachment from the elastic body 30 can be prevented. The internal surface area Ea of the elastic body 30 is the internal surface area measured with the power supply unit 10 housed within the elastic body 30, and can be measured using images of the elastic body 30 and the power supply unit 10 obtained by X-ray or CT (Computed Tomography).

[0028] In this case, if the ratio Ea / Pa is less than 0.4, there is a risk that the power supply unit 10 may fail due to insufficient protection when it detaches from the elastic body 30.

[0029] Figures 2(a) and 2(b) show a sensor module according to an embodiment of the present invention. As shown in Figures 2(a) and 2(b), the sensor module 20 comprises a module body 21 (housing) that integrally houses a power receiving unit 12 that receives power supplied from a power transmission device (power supply device) on the outside of the tire, a power storage unit 13 that stores the received power, and an electronic component 22 including a sensor element that detects tire information. The power receiving unit 12 and the power storage unit 13 are electrically connected, and the power storage unit 13 is electrically connected to the electronic component 22 including the sensor element, and can supply power to the electronic component 22. The module body 21 has a contact surface 21x that contacts the inner surface of the tire. That is, the contact surface 21x is the surface that contacts the bottom surface of the elastic body 30. This contact surface 21x may be bonded to the elastic body 30, but if it is bonded, it will be difficult to replace the sensor module 20.

[0030] Figures 2(a) and (b) show an example in which the power receiving unit 12, power storage unit 13, and electronic components 22 are stacked in that order from the inner surface side of the tire, but this is not the only option, and the stacking order can be appropriately changed according to the various sensor functions. Furthermore, the electronic components 22, including the sensor element, are integrally configured as a sensor unit, and the sensor module 20 is constructed by combining this sensor unit with the power supply unit 10.

[0031] The module body 21 has a structure that houses various electronic components 22 inside. The electronic components 22 can be configured to include various sensors for acquiring tire information, transmitters, receivers, and control circuits. Tire information acquired by the sensors can include the internal temperature and pressure of a pneumatic tire, the amount of wear and deformation of the tread, and abnormal tire conditions (such as separation failures). For example, temperature sensors and pressure sensors are used to measure the internal temperature and pressure. When detecting the amount of wear and deformation of the tire tread, for example, a piezoelectric element is provided as a sensor element, and this sensor element detects an output voltage corresponding to the tire deformation during driving, and the amount of wear of the tread is detected based on that output voltage. In addition, acceleration sensors, magnetic sensors, optical sensors, and sound sensors (microphones) can also be used.

[0032] In such a sensor module 20, at least a portion of the module body 21 is housed in an elastic body 30. The elastic body 30 that houses the module body 21 has a modulus M when stretched to 50%. 50 The modulus M is in the range of 0.3 MPa to 10 MPa. 50 The pressure is preferably in the range of 0.5 MPa to 8.0 MPa, and more preferably in the range of 0.5 MPa to 4.0 MPa.

[0033] The sensor module 20 described above includes a module body 21 that integrally houses a power receiving unit 12 for receiving power, a power storage unit 23 for storing the received power, and an electronic component 22 including a sensor element for detecting tire information. Therefore, the power receiving unit 12 can receive power supplied from a power transmission device on the outside of the tire, and the received power can be stored in the power storage unit 23. This eliminates the need to replace batteries as in conventional systems, enabling long-term use. Furthermore, at least a portion of the module body 21 is housed in an elastic body 30, and the modulus M of the elastic body 30 when stretched to 50% 50 Since the pressure range is between 0.3 MPa and 10 MPa, when the elastic body 30 is deformed, it can adequately maintain its original shape or return to its original state without breaking, thereby mitigating or absorbing the impact and adequately protecting the sensor module 20. This improves the impact resistance of the sensor module 20.

[0034] In the above sensor module, the internal surface area Ea[mm²] of the elastic body 30 2 ] and the outer surface area Ma[mm] of the module body 21 2The ratio Ea / Ma preferably satisfies the relationship 0.5 ≤ Ea / Ma, preferably 0.7 ≤ Ea / Ma, and most preferably 0.8 ≤ Ea / Ma. As the ratio Ea / Ma increases, the contact area between the elastic body 30 and the sensor module 20 increases, and the height of the elastic body 30 (side wall portion 32) increases. The upper limit of the ratio Ea / Ma is preferably 2.0 or less, may be 1.5 or less, or may be 1.0 or less. Furthermore, for example, a configuration in which a second power supply unit (not shown) or a second sensor unit (not shown) is stacked on the module body 21 can be used, in which case the outer surface area Ma of the module body 21 does not include the outer surface area of ​​the stacked second power supply unit and second sensor unit. By setting the ratio Ea / Ma appropriately in this way, damage to the sensor module 20 and detachment from the elastic body 30 can be prevented. The internal surface area Ea of the elastic body 30 is the internal surface area measured with the sensor module 20 housed within the elastic body 30, and can be measured using images of the elastic body 30 and the sensor module 20 captured by X-ray or CT.

[0035] In the elastic body 30 housing the power supply unit and sensor module, the elongation EB[%] at break at 20°C and the modulus M at 100% elongation are specified. 100 [MPa] preferably satisfies the following equation (1). This allows the elongation EB at break at room temperature and the modulus M at high temperature in the elastic body 30 to be determined. 100 This allows for a proper balance between the ease of housing the power supply unit 10 or sensor module 20 into the elastic body 30 and high-speed durability. When housing the power supply unit 10 or sensor module 20 into the elastic body 30, the physical properties of the elastic body 30 at room temperature (20°C) are relevant, while frictional heat is generated between the contact surface of the power supply unit 10 or sensor module 20 and the elastic body 30 during tire rotation, which can degrade the physical properties of the elastic body 30 and reduce its durability. Therefore, the elongation at break EB at room temperature and the modulus M at high temperature of the elastic body 30 are important. 100 It is important to strike the right balance between these factors. 1000 ≥ 275 × M 100 -EB ···(1)

[0036] To further improve the durability of the elastic body 30, 275 × M of the above formula (1) 100 - The value of EB is preferably 950 or less, more preferably 800 or less, and most preferably 700 or less. The lower limit may be 100 or more, 200 or more, or 250 or more.

[0037] Furthermore, in the elastic body 30, the elongation EB at fracture at 20°C is 150% or more, and the modulus M at 100% elongation at 100°C is... 100 It is preferable that the elongation EB at break at 20°C be 5.0 MPa or less. In particular, it is preferable that the elongation EB at break at 20°C be 160% or more, more preferably 180% or more, even more preferably 200% or more, even more preferably 230% or more, even more preferably 250% or more, even more preferably 280% or more, and even more preferably 300% or more. Also, the modulus M at 100% elongation at 100°C 100 The modulus M is preferably 4.9 MPa or less, more preferably 4.7 MPa or less, even more preferably 4.5 MPa or less, even more preferably 4.2 MPa or less, even more preferably 4.0 MPa or less, and even more preferably 3.7 MPa or less. 100 The lower limit is more preferably 1.0 MPa or higher, even more preferably 1.3 MPa or higher, and even more preferably 1.5 MPa or higher, as this makes it easier to prevent the housed power supply unit 10 or sensor module 20 from falling out.

[0038] Here, the elongation at break EB at 20°C is a value confirmed by taking a predetermined rubber test piece (e.g., dumbbell-shaped No. 7) from the elastic body 30, performing a tensile test at a tensile speed of 500 mm / min on this rubber test piece in accordance with JIS K6251:2017, and measuring the elongation at break (elongation rate at break (%): EB) at 20°C. Also, the modulus M at 100% elongation 100A predetermined rubber test piece (e.g., dumbbell-shaped type 7) is taken from the elastic body 30, and a tensile test is performed on this rubber test piece at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and the tensile stress at 100% elongation (MPa:M) is measured. 100 This value is confirmed by measuring it at 100°C.

[0039] Figure 3 shows a pneumatic tire according to an embodiment of the present invention. As shown in Figure 3, the pneumatic tire comprises a tread portion 1 that extends in the circumferential direction of the tire and forms an annular shape, a pair of sidewall portions 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3 arranged radially inward of these sidewall portions 2.

[0040] A carcass layer 4 is mounted between a pair of bead portions 3, 3. This carcass layer 4 includes multiple reinforcing cords extending in the radial direction of the tire, which are folded back from the inside to the outside of the tire around the bead core 5 located in each bead portion 3. A bead filler 6 made of a triangular cross-section rubber composition is placed on the outer circumference of the bead core 5. An inner liner layer 9 is placed in the region between the pair of bead portions 3 on the inner surface Ts of the tire. This inner liner layer 9 forms the inner surface Ts of the tire.

[0041] On the other hand, multiple belt layers 7 (two in Figure 3) are embedded on the outer circumference of the carcass layer 4 in the tread portion 1. These belt layers 7 include multiple reinforcing cords that are inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged to intersect each other between layers. In the belt layers 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set to, for example, a range of 10° to 40°. Steel cords are preferably used as the reinforcing cords of the belt layers 7. On the outer circumference of the belt layers 7, at least one belt cover layer 8 is arranged, in which the reinforcing cords are arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction, for the purpose of improving high-speed durability. Organic fiber cords such as nylon or aramid are preferably used as the reinforcing cords of the belt cover layer 8.

[0042] The tire internal structure described above is a typical example of a pneumatic tire, but is not limited to this example.

[0043] In the above-described pneumatic tire, at least one power supply unit 10 or sensor module 20 can be attached to the inner surface Ts of the tire. In this case, it is preferable that the power receiving section 12 of the power supply unit 10 is arranged parallel to the inner surface Ts of the tire. In particular, it is more preferable that the power receiving section 12 is arranged such that the angle between the central axis of the coil inside the power receiving section 12 and the inner surface Ts of the tire is 45° to 135°.

[0044] This arrangement of the power receiving unit 12 is suitable when the power receiving unit 12 receives power supplied from a power transmission device on the outside of the tire. It can be attached to the inner surface Ts of the tire corresponding to any of the tread portion 1, sidewall portion 2, or bead portion 3. However, if the sensor function is intended to detect road surface or wear, it is desirable to detect the behavior of the tire contact surface, so it is preferable to attach it to the inner surface Ts of the tire corresponding to the tread portion 1. Also, if fault detection is intended, it is desirable to attach it near the part to be detected, so it can be attached to the inner surface Ts of the tire corresponding to any part.

[0045] Furthermore, in the above-described pneumatic tire, in addition to the belt layer 7 arranged in the tread portion 1, an additional reinforcing layer containing multiple steel cords can be arranged in the sidewall portion 2. A power supply unit 10 or a sensor module 20 is arranged in the area of ​​the inner surface Ts of the tire corresponding to the area where such a reinforcing layer (belt layer 7 or additional reinforcing layer) is arranged. At this time, in a front view of the reinforcing layer (belt layer 7 or additional reinforcing layer), the ratio (×100%) of the area of ​​the portion excluding the steel cords to the area of ​​the reinforcing layer is preferably in the range of 5% to 60%, and more preferably in the range of 10% to 45%. This area ratio (gap ratio) is calculated by using an image of the reinforcing layer taken from the outer surface side of the tire by X-ray or CT, extracting a 30 mm square area (for example, area S1 or area S2 shown in Figure 4) from the image, and binarizing it by image processing. For example, in the case of the tread portion 1, either the center region S1 or the shoulder region S2 may be used. However, if the shoulder region S2 is used, a 30 mm square region is targeted, with one end of region S2 being 5 mm inward in the tire width direction from the end Ae of the intersection region A of the inner belt layer 7A in the tire radial direction and the outer belt layer 7B in the tire radial direction.

[0046] By setting the area ratio (gap ratio) appropriately in this way, the power receiving function of the power receiving unit 12 and the power storage function of the power storage unit 13 can be fully performed while ensuring the effectiveness of the reinforcing layer (for example, trajectory retention, damage resistance, and turning ability). Such a reinforcing layer is preferably composed of three or fewer layers, and more preferably composed of two or three layers.

[0047] If the area ratio is less than 5%, sufficient gaps between the steel cords cannot be secured, resulting in reduced power supply efficiency. Conversely, if the area ratio exceeds 60%, the reinforcing layer may not be sufficiently effective, leading to reduced course retention and damage resistance. While reinforcing cords made of aramid fibers can be used in the reinforcing layer to improve power supply efficiency, this is not ideal from the standpoint of handling stability (course retention, turning ability, etc.).

[0048] Although Figures 3 and 4 show an example in which the sensor module 20 is attached to the inner surface Ts of the tread portion 1 of the tire, the system is not limited to this. For example, if the power supply unit 10 or the sensor module 20 is attached to the inner surface Ts of the sidewall portion 2 of the tire, the gap ratio is calculated based on the steel cords of the additional reinforcing layer placed on the sidewall portion 2, similar to the case of the belt layer 7 described above.

[0049] Next, the wireless power supply system of the parallel resonant circuit of the present invention will be described. In the wireless power supply system of the present invention, the power receiving circuit section 700 described later can be replaced with the power receiving section 12 of the power supply unit 10 or the power receiving section 12 of the sensor module 20, and the capacitor 74 described later can be replaced with the power storage section 13 of the power supply unit 10 or the power storage section 13 of the sensor module 20.

[0050] Figure 5 shows a basic circuit diagram of a wireless power supply system 50 according to an embodiment of the present invention. As shown in Figure 5, the wireless power supply system 50 is composed of a power supply device 60 and a power receiver 70. The power supply device 60 supplies electrical energy to the power receiver 70.

[0051] As shown in Figure 5, the power receiver 70 consists of a power receiving coil 71, a power receiving side resonant capacitor 72, a rectifier circuit 73, a capacitor 74, and a power receiving side frequency adjustment circuit 75. Both ends of the power receiving coil 71 are connected to the capacitor 74 via the rectifier circuit 73. The power receiving side resonant capacitor 72 is connected in parallel with the power receiving coil 71. In this case, the resonant capacitor 72 is composed of one or more capacitors in parallel. A frequency adjustment circuit 75 is connected between the resonant capacitor 72 and the rectifier circuit 73, and this frequency adjustment circuit 75 adjusts the frequency of the rectifier circuit 73. The power receiving side frequency adjustment circuit 75 consists of a frequency adjustment element, which is a capacitor or inductor element, and a FET switching element. Note that if the resonant frequency is constant, the resonant frequency can be tuned during manufacturing using the frequency adjustment element, so in that case, the FET switching element is not necessarily required.

[0052] There are several distinctive features of the power receiver 70. Firstly, the power receiver 70 is equipped with some kind of capacitor 74. Secondly, the size, material, and electrical specifications of the power receiving coil 71 in the power receiver 70 and the power supply coil 61 of the power supply device 60 are designed according to the power supply range, power supply distance, and power supply capacity. Thirdly, the power receiving coil 71 of the power receiver 70 and the resonant capacitor 72 on the power receiving side are configured as a so-called resonator (LC resonant circuit) and are configured to have good characteristics at a predetermined resonant frequency. (The same applies to the power supply coil 61 and the resonant capacitor 62 of the power supply device 60.) Fourthly, if the power receiver 70 is a parallel resonant circuit, half-wave rectification is sufficient for the rectifier circuit.

[0053] In the power receiver 70 of this embodiment, the power receiving coil 71, the resonant capacitor 72, the rectifier circuit 73, and the frequency adjustment circuit 75 constitute a power receiving circuit section 700 that recovers the energy generated in the power receiving coil 71 by electromagnetic induction. The power receiving circuit section 700 does not include a capacitor 74.

[0054] In this invention, because the allowable deviation range of the resonant frequency is large, it is possible to realistically address variations in the electrical performance of manufactured products, also known as yield issues. Therefore, it is conceivable to define the resonant frequency for each model.

[0055] The power supply device 60 includes a power supply coil 61, a resonant capacitor 62 that forms a resonant circuit together with the power supply coil 61, a switch circuit 63 for turning power on and off to the power supply coil 61, and a control circuit 64 that operates the switch circuit 63. The resonant capacitor 62 on the power supply side is composed of one or more capacitors in parallel. A frequency adjustment circuit 65 (a circuit including, for example, a PLL circuit) that creates the on / off timing of the switch is connected to the control circuit 64. A resonant state sensor 66 that detects the resonant state is included in the control circuit 64. This is composed of, for example, a phase detection circuit. A current measurement circuit 67 and a voltage sensor 68 are connected to the resonant state sensor 66. The power supply device 60 is also provided with a power supply 69 that supplies power to the power supply coil 61 and supplies the necessary power to each circuit.

[0056] The characteristics of the power supply device 60 are as follows: Firstly, the power supply coil 61 and the resonant capacitor 62 form a parallel resonant circuit. Secondly, there is one switch circuit. When this switch is turned on, it is in a driving state, and when it is turned off, it is in a resonant state. Thirdly, the control circuit 64 uses the timing of the frequency adjustment circuit 65 to control the switch circuit 63, thereby controlling the timing of the driving state and the resonant state. Fourthly, it has a resonant state sensor 66 that detects the resonant state (mainly the frequency deviation), and the control circuit 64 performs control to stop power supply or adjust the resonant frequency based on the detection result of the resonant state sensor 66.

[0057] In the power supply device 60 of this embodiment, the power supply coil 61, the resonant capacitor 62, the switch circuit 63, the control circuit 64, the frequency adjustment circuit 65, the resonant state sensor 66, the current measurement circuit 67, and the voltage sensor 68 constitute a power supply circuit section 600 that supplies power to generate magnetic flux in the power supply coil 61. The power supply circuit section 600 does not include a power supply 69.

[0058] Figure 5 shows a basic circuit diagram (closer to a block diagram). In the basic circuit, a power supply coil 61 is provided, which generates magnetic flux and causes electromagnetic induction. At least the electrical circuit of the power supply device 60 is equipped with a resonant capacitor 62 and a power supply 69 for the power supply device 60, which establish a resonant relationship with the power receiving coil 71 of the power receiver 70 at a certain frequency. This frequency is called the resonant frequency, and generally, a long wave frequency that has little effect on the human body is used. If this is considered the reference resonant frequency, the reference resonant frequency used in the present invention is not particularly limited. On the other hand, an important feature of the present invention is that the resonant frequencies of the power supply side and the power receiving side, which will be described later, are not usually matched to the same resonant frequency, but are shifted based on a predetermined timing time.

[0059] There is an appropriate resonant frequency depending on the distance between the power supply coil 61 and the power receiving coil 71. The positional relationship and condition of the power receiving coil 71 in the power receiver 70 will cause a slight shift in the resonant frequency. For example, the situation will change depending on the position and inclination of the power receiving coil 71 in the power receiver 70. Therefore, if the power receiving coil 71 is within the range reached by the magnetic flux emitted from the power supply coil 61, energy can be supplied. At this time, the magnetic coupling state between the coil windings is represented by a coefficient that indicates the degree of coupling, which is generally called the coupling coefficient (K). The present invention also has a distinctive feature regarding the method of determining a predetermined coupling coefficient that improves power supply efficiency.

[0060] The presence of the receiving coil 71 in the magnetic flux affects the power supply device 60 in the form of a shift in the resonant frequency. A shift in the resonant frequency reduces the efficiency of energy supply. Therefore, the shifted frequency and phase are detected by a resonance state sensor 66 (for example, a circuit including a phase detection circuit), and the resonant frequency of the power supply coil 61 is adjusted according to that frequency and phase. For example, this can be done by changing the resonant capacitor 62. This adjustment is also called tuning, and there are methods that are performed during manufacturing and methods that are automatically controlled by an adjustment circuit during operation, but they are collectively called frequency adjustment circuits. The resonant capacitor is composed of one or more capacitors, but the simplest tuning method is to connect several types of capacitors in parallel beforehand, and then during manufacturing, unnecessary capacitors are cut from the pattern to disable them and adjust them to achieve a predetermined resonant frequency. Alternatively, trimmer capacitors, variable capacitors, etc., can be placed and manually adjusted with an adjustment knob.

[0061] Another method for automatically controlling the operation using an adjustment circuit is to pre-connect several pairs of capacitors and switches in parallel, and then have the adjustment circuit control the switches connected in series with each capacitor to achieve a predetermined resonant frequency. Alternatively, a servo motor can be attached to the adjustment knob of a variable capacitor, and the adjustment circuit controls the servo motor to achieve a predetermined resonant frequency.

[0062] On the other hand, while the receiving side often uses a method of adjustment during manufacturing, a method of pre-measuring the inductance of the receiving coil and then installing a capacitor of the appropriate value in the unmounted section can also be considered a frequency adjustment circuit in a broad sense.

[0063] Connecting capacitors in parallel reduces internal resistance and further suppresses heat generation. Furthermore, the frequency adjustment circuit 65, for example, incorporates a PLL (Phase-Locked Loop) circuit, allowing for adjustment of the power supply capacity by lengthening or shortening the operating time. In some cases, it is also possible to change the resonant frequency by switching between multiple power supply coils 61. Here again, a key feature of this invention is that the optimal resonant frequency adjustment value is determined by a shifted resonant frequency based on a predetermined timing time, as described later.

[0064] Adjusting the frequency (or phase) requires considering various factors. Therefore, it is preferable to provide a control circuit 64 that performs programmatic control using a microcontroller (an integrated circuit including a processor, memory, and peripheral circuits) or a programmable logic device (an integrated circuit that can define and change its internal logic circuits). The control circuit 64 is connected to a resonance state sensor 66 (phase detection circuit). The resonance state sensor 66 senses frequency deviations and phase deviations and transmits the signal to the control circuit 64. As a result, when an object other than the designated power receiver 70 approaches, the resonance state sensor 66 detects abnormal frequency or phase and transmits the signal to the control circuit 64, which then acts on the power supply 69 to stop the power supply.

[0065] However, since this system uses tires in which the steel cords of the aforementioned reinforcing layer (belt layer 7 or additional reinforcing layer) are embedded, a certain amount of energy loss is detected. Assuming the tire is in the predetermined position, the system determines whether or not there is an abnormality.

[0066] The wireless power supply system of the present invention is composed of the basic circuit shown in Figure 5. The resonant capacitor 62 of the power supply device 60 is connected in parallel with the power supply coil 61. The circuit in which this resonant capacitor 62 is located is generally called a parallel resonant circuit. On the other hand, in commonly used wireless power supply systems, a series resonant circuit is formed, and the resonant capacitor is located in series with the coil.

[0067] In this parallel resonant circuit, a key feature is that when SW1 is turned on and a stable resonant state is achieved, and then SW1 is turned off, the power supply device 60 maintains a resonant state with the power receiver 70 while the energy stored in the power receiving coil 71 and the resonant capacitor 72 is released. Here, based on the resonant state transition detected by the resonant state sensor 66 connected in parallel with the power supply coil 61, the control circuit 64 realizes power supply at an appropriate frequency through timing control of the resonant capacitor and the drive state by the frequency adjustment circuit 65 (PLL circuit). This resonant state sensor 66 is a sensor that detects the resonant state, and detects voltage and current transitions, as well as phase detection of the resonant frequency.

[0068] A detailed example of the switch circuit 63 in Figure 5 consists of an N-channel MOSFET and a Schottky barrier diode. Similarly, a detailed example of the rectifier circuit 73 of the power receiver 70 consists of a capacitor, a voltage stabilization circuit 76, and a Schottky barrier diode 77. The Schottky barrier diode 77 may be a rectifier diode. These are merely examples, and the appropriate configuration should be chosen according to the product specifications.

[0069] Furthermore, a flyback switch is provided to switch between utilizing or short-circuiting the Schottky barrier diode that constitutes the switch circuit 63. When the Schottky barrier diode element is utilized, it is called the "resonant method," and when the Schottky barrier diode element is short-circuited, it is called the "flyback method." The flyback switch FS(SW2) may be provided as an electronic switch to be switched, or it may be manually shorted using jumper pins or the like. In some cases, when using only the flyback method, the diode may not be implemented, and a short pattern may be implemented instead.

[0070] In the case of a resonant power supply system, the basic waveform diagram of the power supply device (when SW2=OFF) is the waveform diagram shown in Figure 6, which will be described later. In the case of a flyback power supply system, the waveform diagram is the "basic waveform diagram of the power supply device (when SW2=ON)" shown in Figure 7.

[0071] Figure 6 shows the basic waveform diagram of the power supply device according to the present invention (when SW2 = OFF). That is, it is a waveform diagram of the resonant type. In Figure 6, the waveform of the drive current is omitted. Also, the resonant coil current is omitted and the power receiving coil voltage is drawn. The resonant coil voltage is omitted and the power supply coil voltage is drawn.

[0072] In Figure 6, there is a drive voltage pulse P1, which is depicted as a rectangular shape, representing the pulse waveform used to control the switch circuit 63. This drive voltage pulse P1 is the waveform of the signal supplied from the control circuit 64 in Figure 5 to the switch circuit 63, and is precisely the pulse generated by the control circuit 64 to control the switch circuit 63 based on the timing of the frequency adjustment circuit 65. The switch turns on when the drive voltage pulse P1 is high. In other words, when the switch is turned on, power from the power supply 69 is supplied to the resonant capacitor 62 of the power supply device 60, thus creating a driven state. This driving time DT1(t1) is called the drive pulse width PW1.

[0073] When the switch is off and the device is not operating, it enters a resonant state, or resonant time. The resonant time RT(t2) is referred to as the resonant period SC1(t2) of the power supply device.

[0074] As shown in Figure 5, when the power supply coil 61 and the resonant capacitor 62 form a parallel resonant circuit, it is safe to say that the power supply device 60 will continue to supply energy as long as it is in a resonant state with the power receiver 70, whether in a driving state or a resonant state. That is, the resonant period RC1(t3) on the power receiver side is adjusted by adjusting the frequency adjustment circuit so that 0.6(t1+t2)≦t3≦1.1(t1+t2) is satisfied with respect to the sum of the time of the resonant state (t2) and the driving state (t1) of the power supply device 60.

[0075] When the switch circuit 63 is turned on, that is, while the drive voltage pulse P1 is supplied, the power supply coil voltage V1 is kept near zero (or it can be said that the drive voltage pulse P1 is supplied at the timing when it is near zero). Also, the power receiving coil voltage V2 shows a distorted waveform as a result during the driving time DT1. During the driving time DT1, the power supply coil voltage V1 is zero, and the drive current is flowing. The drive current is the waveform at a point along the path from the switch circuit 63 to the resonant capacitor 62 of the power supply device 60 in Figure 5. The resonant capacitor 62 of the power supply device 60 appears as an AC waveform with a 90-degree phase shift from the resonant coil current, but the drive current is a portion of the electrical energy stored in the resonant capacitor 62 that has been converted.

[0076] When an electric current flows, it is converted into a magnetic flux output from the power supply coil 61 and acts on the power receiving coil 71 of the power receiver 70. At this time, it can be said that energy transfer occurs due to electromagnetic induction.

[0077] Once the specifications for the drive pulse width PW1 are determined, the design value of the resonator between the power supply coil 61 and the resonant capacitor 62 of the power supply device 60, i.e., the resonant frequency, can be determined. The resonant frequency of the power supply device 60 is determined by the period time of the resonant period SC1 of the power supply device 60. On the other hand, in the power receiver 70, the resonant period RC1 of the power receiver side is determined by the period time of the sum of the period time of the drive pulse width PW1 and the resonant period SC1 of the power supply device 60. Thus, a feature of the present invention is that the resonant frequency of the power supply device 60 and the resonant frequency of the power receiver 70 are adjusted with a predetermined difference.

[0078] In this invention, the magnetic flux from the power supply device must pass through the reinforcing steel cord embedded in the tire and reach the receiving coil of the power receiver, and it is assumed that the coupling is small. Appropriately determining this coupling coefficient is an important element, and it is desirable to set the coupling coefficient K to a range of 0.3 (30%) or less, or close to it. A weak coupling can be achieved by adjusting the size, number of turns, and inductance of the power supply coil and the power receiving coil. For example, if the coupling coefficient is too weak when measured at the required power supply distance between the power supply coil and the power receiving coil, the coupling coefficient can be increased by, for example, increasing the size of the power receiving coil (inner diameter of the coil) or increasing the number of turns. In particular, a range of approximately K = 0.05 to 0.3 (5% to 30%) is the range of power supply efficiency in which energy can be efficiently transmitted. Conversely, the specifications of the drive pulse width, the specifications of the power supply coil and the receiving coil, and the specifications of the power supply range and power supply distance should be determined so that the coupling coefficient falls within this range.

[0079] Furthermore, the coupling coefficient is closely related to the power supply distance. The higher the coupling coefficient, the higher the power supply efficiency. The position with the highest power supply efficiency is when the power supply distance is zero. The coupling coefficient increases when the distance between the power supply coil and the power receiving coil is short, and decreases when they are far apart. In this invention, the power supply efficiency is high when the coupling coefficient is relatively low, around K = 0.05 to 0.3 (5% to 30%), so high power supply efficiency can be achieved when the power supply coil and the power receiving coil are placed at a certain distance apart.

[0080] Figure 7 shows the basic waveform diagram of the power supply device according to the present invention (when SW2=ON). In other words, it is a waveform diagram of the flyback method. When SW2=ON, the diode is short-circuited, resulting in the flyback method. Compared to the waveform of the resonant method with SW2=OFF, the power supply coil voltage V3 only appears in the positive direction. The drive pulse width PW2 and drive time DT2 can be made longer. Basically, it can be set to a maximum of slightly less than half a cycle of the resonant period SC2 of the power supply device.

[0081] The longer the driving time (driving pulse width), the more current flows through the coil, generating a magnetic flux in the power supply coil 61. This magnetic flux also passes through the power receiving coil 71 of the resonant receiver 70, causing current to flow. However, it's not necessarily true that setting the driving voltage pulse P2 for the full half-cycle is sufficient. The power supply capacity plateaus beyond a certain time (width). Therefore, slightly shortening the period to less than half a cycle improves power supply efficiency.

[0082] In the flyback configuration, the relationship between the power supply resonant period and the receiver resonant period is not such that the sum of the resonant time and the drive time equals the receiver resonant period. However, by optimizing the simulation performed using the resonant method, it is sufficient to ensure that the sum of the resonant state time (t2) and the drive state time (t1) (t1+t2) satisfies the condition 0.6(t1+t2)≦t3≦1.1(t1+t2). Alternatively, the interval of the drive voltage pulse P2 becomes the resonant period SC2 of the power supply, and this can be adjusted to match the resonant period RC2 of the receiver.

[0083] Figure 8 shows a configuration diagram of a wireless power supply system according to an embodiment of the present invention. A power receiver 70 is built into the tire T. The tire T is in a state where it can rotate. For example, it may be mounted on a car, or it may be attached to a dedicated device. The power supply device 60 is installed in a predetermined location, but it is positioned so that the power receiver 70 is within the power supply range, that is, close to the tire T. When the tire T rotates, the power receiver 70 approaches the power supply device 60, causing a current change in the current measurement circuit 67, such as a current value At measured by the current measurement circuit. Also, a voltage change occurs in the voltage sensor 68, such as a voltage value Vt measured by the voltage sensor. The control circuit 64 detects and determines this, and notifies the system that the power receiver 70 has approached by a predetermined communication means or by a function that notifies with light or sound. By fixing the power receiver 70 in that position, the power receiver 70 efficiently charges the battery built into the tire T wirelessly.

[0084] Furthermore, a reinforcing layer of steel cords Sc is embedded in the tire T, which obstructs the magnetic flux and results in energy loss. At this time, a constant current value is observed in the current measurement circuit 67. A constant voltage value is also observed in the voltage sensor 68. Based on the changes in the measured current value of the current measurement circuit 67 and the voltage value of the voltage sensor 68, the control circuit 64 detects the energy loss. This also makes it possible to determine whether the tire T is in a predetermined position. For example, it is possible to sense that the tire T has entered the power supply range of the power supply device (is in a predetermined position), notify the device of this using a predetermined communication means or by light or sound, rotate the tire T, and as described above, notify the device that the power receiver 70 is approaching (the power receiver 70 has entered the power supply range of the power supply device 60), and wirelessly charge the capacitor from the power receiver 70.

[0085] Although the explanation described a scenario where the power supply device is fixed and the tire rotates, the same principle can be applied in the reverse scenario: the tire is fixed, and the power supply device is operated to rotate around the tire's circumference. The same mechanism can then be used to detect whether the power receiver has entered the power supply range. [Examples]

[0086] The tire size is 225 / 45R18, and it is equipped with a power supply unit having a unit body that integrally houses a power receiving section and a power storage section, at least a part of this unit body is housed in an elastic body, and this elastic body is fixed to the inner surface of the tire, modulus M 50 Comparative Example 11 and Examples 11-15 tires were manufactured with the ratio Ea / Pa set as shown in Table 1.

[0087] The ability to supply power to these test tires was evaluated using the test method described below, and the results are shown in Table 1.

[0088] Each test tire was mounted on a wheel with a rim size of 18 x 7.5J, and a driving test was conducted on a drum test machine under the following conditions: air pressure of 230 kPa, load of 4.5 kN, driving speed of 81 km / h, and driving distance of 15,000 km. Afterwards, power was supplied from the outside of the tire using a power transmission device to check whether the power supply unit could supply power. The evaluation results were shown as "D (Not Possible)" if power could not be supplied and "C (Acceptable)" if power could be supplied. Furthermore, if power could be supplied when the driving distance was extended to twice the above driving distance, it was shown as "B (Good)", if power could be supplied when the driving distance was extended to three times the above driving distance, it was shown as "A (Excellent)", and if power could be supplied when the driving distance was extended to four times the above driving distance, it was shown as "AA (Best)".

[0089] [Table 1]

[0090] As can be seen from Table 1, the tires of Examples 11 to 15 were found to have a longer power supply range compared to Comparative Example 11. This indicates that the power supply unit is adequately protected by the elastic material, resulting in improved impact resistance.

[0091] Furthermore, the sensor module has a module body with a tire size of 225 / 45R18, which integrally houses an electronic component including a power receiving unit, a power storage unit, and a sensor element. At least a portion of this module body is housed in an elastic body, and this elastic body is fixed to the inner surface of the tire, and the modulus M 50 Comparative Example 21 and Examples 21-26 tires were manufactured with the ratio Ea / Ma set as shown in Table 2.

[0092] The ability to supply power to these test tires was evaluated using the following test method, and the results are shown in Table 2.

[0093] Each test tire was mounted on a wheel with a rim size of 18 x 7.5J, and a driving test was conducted on a drum test machine under the following conditions: air pressure of 230 kPa, load of 4.5 kN, driving speed of 81 km / h, and driving distance of 15,000 km. Afterwards, power was supplied from the outside of the tire using a power transmission device to check whether the sensor module could be powered. If power could not be supplied, it was indicated as "D (Not Possible)", and if power could be supplied, it was indicated as "C (Acceptable)". Furthermore, if power could be supplied when the driving distance was extended to twice the above driving distance, it was indicated as "B (Good)", if power could be supplied when the driving distance was extended to three times the above driving distance, it was indicated as "A (Excellent)", and if power could be supplied when the driving distance was extended to four times the above driving distance, it was indicated as "AA (Best)".

[0094] [Table 2]

[0095] As can be seen from Table 2, the tires of Examples 21 to 26 were found to have a longer power supply range compared to Comparative Example 21. This indicates that the sensor module was adequately protected by the elastic material, resulting in improved impact resistance.

[0096] Furthermore, elastic bodies having the composition shown in Table 3 and the shape shown in Figure 2 were attached to tires of size 225 / 45R18. For the tires of the obtained standard example 31 and examples 31-35, the modulus M at 100% elongation of the elastic body was determined as follows. 100 In addition, the elongation EB at break at 20°C was measured, and an indoor durability test was conducted.

[0097] Modulus M at 100% stretch 100 : From the elastic body of each tire obtained, a dumbbell-shaped rubber test piece of type 7 (thickness 1.0 ± 0.1 mm) was taken, and a tensile test was performed on this rubber test piece at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and the tensile stress at 100% elongation (MPa: M) was measured. 100 The temperature was measured at 100°C. The results are shown in the middle section of Table 3.

[0098] Elongation at break (EB) at 20°C: From the elastic bodies of each tire obtained, dumbbell-shaped rubber test pieces of type 7 (thickness 1.0 ± 0.1 mm) were taken. Tensile tests were performed on these rubber test pieces at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and the elongation at break (elongation rate at break (%): EB) was measured at 20°C. The results are shown in the middle section of Table 3.

[0099] Indoor durability test: Each tire, equipped with a sensor module using a piezoelectric element as the sensor element and mounted on an elastic body, underwent pretreatment by being filled with 350 kPa of oxygen and stored at 80°C for 5 days. It was then assembled onto a wheel and subjected to an indoor driving test using a drum testing machine, with the driving conditions starting at 81 km / h and increasing by 10 km / h every 2 hours. The speed at which the elastic body broke was used as the evaluation result. This breakage of the elastic body was defined as a state where the sensor module could no longer function due to cracking or detachment of the elastic body. These results are shown in the lower section of Table 3. For Examples 31-35, the values ​​are shown as an index with the value of Reference Example 31 set to 100.

[0100] [Table 3]

[0101] Detailed information on each component in Table 3 above is as follows: NR: Natural rubber (STR20, manufactured by Bombandit) BR: Butadiene rubber (Nipol BR1220, manufactured by Nippon Zeon Co., Ltd.) CB1: Carbon Black (Show Black N330, Nitrogen Adsorption Specific Surface Area (N2SA): 71m²) 2 (Manufactured by Cabot Japan Co., Ltd.) CB2: Carbon Black (Show Black N660, Nitrogen Adsorption Specific Surface Area (N2SA): 34m²) 2 (Manufactured by Cabot Japan Co., Ltd.) Oil: Aroma oil (Diana Process NH-70S, manufactured by Idemitsu Kosan Co., Ltd.) Zinc oxide: Zinc oxide (Ginrei R, manufactured by Toho Zinc Co., Ltd.) Stearic acid: Bead stearic acid, Kiri (manufactured by Chiba Fatty Acid Co., Ltd.) Anti-aging agent: 6PPD (manufactured by Flexis) Sulfur: Sulfax 5 (manufactured by Tsurumi Chemical Industries Co., Ltd.) Vulcanization accelerator: Noxellar DM-PO (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)

[0102] As can be seen from Table 3, the tires of Examples 33-35 showed improved high-speed durability compared to the standard example 31. The tires of Examples 31 and 32 did not show any deterioration in high-speed durability compared to the standard example 31, and their performance remained unchanged.

[0103] Examples 41 to 46 were manufactured in which a 225 / 45R18 tire had the basic structure illustrated in Figure 3, and an elastic body with the shape shown in Figure 2 was attached to the inner surface of the tire while housing a sensor module, and the gap ratio of the steel cords constituting the belt layer and the number of belt layers were varied as shown in Table 4.

[0104] These test tires were evaluated for handling stability and power supply capability using the following test methods, and the results are shown in Table 4.

[0105] Stability: Each test tire was mounted on a wheel with a rim size of 18 x 7.5J and fitted to a test vehicle (2000cc engine displacement). The tire pressure was set to 230kPa, and a test driver conducted a subjective evaluation of the handling stability on a paved test course. The evaluation results were scored on a 10-point scale, with 5 points being the baseline. A higher score indicates better handling stability.

[0106] Power supply availability: Power was supplied from the outside of the tire using a power transmission device to check whether the sensor module could receive power. The evaluation results were indicated as "○ (possible)" if power could be supplied and "× (unable)" if power could not be supplied.

[0107] [Table 4]

[0108] As can be seen from Table 4, the tires of Examples 41 to 46 were all able to supply power. In particular, the tires of Examples 41 to 44 had superior handling stability, exceeding the reference point.

[0109] This disclosure encompasses the following inventions [1] to

[15] . The invention [1] comprises a unit body integrally housing a power receiving unit for receiving power and a power storage unit for storing the received power, wherein at least a part of the unit body is housed in an elastic body, and the modulus M when the elastic body is stretched to 50% 50 This power supply unit is characterized by having a pressure range of 0.3 MPa to 10 MPa. The invention [2] relates to the internal surface area Ea [mm²] of the elastic body. 2 ] and the outer surface area Pa[mm] of the unit body 2 The power supply unit according to the invention [1] is characterized in that the relationship between ] and 0.4 ≤ Ea / Pa is satisfied. The invention [3] relates to the elongation EB[%] at break of the elastic body at 20°C and the modulus M when the elastic body is 100% stretched. 100 The power supply unit according to invention [1] or [2] is characterized in that [MPa] and satisfy the relationship shown in formula (1) below. 1000 ≥ 275 × M 100 -EB ···(1) The invention [4] comprises a module body that integrally houses a power receiving unit for receiving power, a power storage unit for storing the received power, and electronic components including a sensor element for detecting tire information, wherein at least a part of the module body is housed in an elastic body, and the modulus M when the elastic body is stretched to 50% 50 This sensor module is characterized by having a pressure range of 0.3 MPa to 10 MPa. The invention [5] relates to the internal surface area Ea [mm²] of the elastic body. 2 ] and the outer surface area Ma[mm] of the module body 2The invention is a sensor module according to [4], characterized in that the relationship between ] and 0.5 ≤ Ea / Ma is satisfied. The invention [6] relates to the elongation EB[%] at break of the elastic body at 20°C and the modulus M of the elastic body when stretched to 100%. 100 The sensor module according to invention [4] or [5] is characterized in that [MPa] and satisfy the relationship of formula (1) below. 1000 ≥ 275 × M 100 -EB ···(1) Invention [7] is a tire having a power supply unit according to any of Inventions [1] to [3] on its inner surface, wherein a reinforcing layer containing a plurality of steel cords is arranged, the power supply unit is arranged in a region of the inner surface of the tire corresponding to the area where the reinforcing layer is arranged, and in a front view of the reinforcing layer, the ratio of the area of ​​the portion excluding the steel cords to the area of ​​the reinforcing layer is in the range of 5% to 60%. Invention [8] is a tire having a sensor module according to any of Inventions [4] to [6] on its inner surface, wherein a reinforcing layer containing a plurality of steel cords is arranged, the sensor module is arranged in a region of the inner surface of the tire corresponding to the area where the reinforcing layer is arranged, and in a front view of the reinforcing layer, the ratio of the area of ​​the portion excluding the steel cords to the area of ​​the reinforcing layer is in the range of 5% to 60%. Invention [9] is a tire equipped with a power supply unit according to any of Inventions [1] to [3], characterized in that the power receiving unit is arranged parallel to the inner surface of the tire. Invention

[10] is a tire equipped with a sensor module according to any of Inventions [4] to [6], characterized in that the power receiving unit is arranged parallel to the inner surface of the tire. Invention

[11] is a wireless power supply system comprising a tire having a power supply unit according to any one of Inventions [1] to [3] or a sensor module according to any one of Inventions [4] to [6] on its inner surface, a power supply unit having a power supply unit according to any one of Inventions [1] to [3] or a sensor module according to any one of Inventions [4] to [6] disposed as a power receiving unit of the power supply unit or a power receiving unit of the sensor module and receiving power wirelessly, and a power supply device including a power supply circuit unit that wirelessly supplies power to the power receiving unit, wherein the power supply circuit unit has at least a power supply coil that generates magnetic flux and supplies power to the power supply coil to generate magnetic flux, the power receiving circuit unit has at least a power receiving coil that receives magnetic flux emitted from the power supply coil and recovers energy generated in the power receiving coil by electromagnetic induction, and a power supply side resonant capacitor that forms a parallel resonant circuit so that the power supply circuit unit resonates at a predetermined resonant period in combination with the power supply coil, and a power supply device that flows a drive current to the power supply coil The wireless power supply system is characterized by having a switch circuit that realizes an on state and a switch off state that cuts off the drive current, a control circuit that inputs a drive pulse signal to control on and off to the switch circuit and adjusts the timing of inputting the drive pulse signal, the power receiving circuit having a power receiving side resonant capacitor that forms a resonant circuit so as to resonate at a predetermined resonant period in combination with the power receiving coil, and when the power supply device is installed in a location close to a part of the tire and the power receiving unit is located within the power supply range of the power supply device, the frequency adjustment circuit further having a frequency adjustment circuit that appropriately fine-tunes the capacitance of the power supply side resonant capacitor or the inductance of the power supply coil with respect to the distance between the power receiving unit and the power supply device, and fine-tunes the resonant period of the power supply device at the timing of inputting the drive pulse signal to appropriately control the distance between the power receiving unit and the power supply device. The invention

[12] is a wireless power supply system according to the invention

[11] , characterized in that a magnetic flux passes through the steel cords of the reinforcing layer embedded in the tire by coupling obtained by adjusting the size, number of turns and inductance of the power supply coil and the power receiving coil so that the coupling coefficient K between the power supply coil and the power receiving coil is in the range of K = 0.3 or less. Invention

[13] is a wireless power supply system according to Invention

[11] or

[12] , characterized in that the power supply circuit unit has a current measuring circuit and a voltage sensor for measuring the current flowing through the power supply coil, the tire is in a state of rotation, the power supply device is installed in a location close to a part of the tire, the current measuring circuit measures changes in current, the voltage sensor measures changes in voltage, the measured information is input to the control circuit, and when the power receiving unit enters the power supply range of the power supply device due to the rotation of the tire, the control circuit has a function to notify by predetermined means or by light or sound when it senses that the power receiving unit is within the power supply range of the power supply device based on the change in the current value of the current measuring circuit and the change in the voltage value of the voltage sensor. The invention

[14] is a wireless power supply system according to the invention

[11] or

[12] , characterized in that the power supply circuit unit has a current measuring circuit and a voltage sensor for measuring the current flowing through the power supply coil, the power supply device is in a state of rotating around the outer circumference of the tire, the power supply device is installed in a location close to a part of the tire, the current measuring circuit measures changes in current, the voltage sensor measures changes in voltage, the measured information is input to the control circuit, and when the power receiving unit enters the power supply range of the power supply device as the power supply device rotates around the outer circumference of the tire, the control circuit has a function to notify by predetermined communication means or by light or sound when it senses that the power receiving unit is within the power supply range of the power supply device based on changes in the current value of the current measuring circuit and changes in the voltage value of the voltage sensor. The invention

[15] is a wireless power supply system according to the invention

[11] or

[12] , characterized in that the power supply circuit section has a current measuring circuit and a voltage sensor for measuring the current flowing through the power supply coil, the power supply device is installed in close proximity to a part of the tire, the current measuring circuit measures changes in current, the voltage sensor measures changes in voltage, the measured information is input to the control circuit, and when the tire enters the power supply range of the power supply device, the control circuit detects energy loss due to steel cords in a reinforcing layer embedded in the tire based on changes in the current value of the current measuring circuit and the voltage value of the voltage sensor, and when it senses that the tire is in a predetermined position, it has a function to notify by predetermined means or by light or sound. [Explanation of Symbols]

[0110] 1. Tread section 2 Sidewall section 3. Bead section 10 Power supply units 11 Unit body 12 Power receiving section 13. Energy Storage Unit 20 Sensor Modules 21 Module body 22 Electronic Components 30 Elastic body 31 Base 32 Side wall section 50 Wireless power supply systems 60 Power supply device 70 Power receiver Ts inner surface of tire CL tire centerline

Claims

1. The unit body comprises a power receiving section for receiving power and a power storage section for storing the received power, and at least a part of this unit body is housed in an elastic body, wherein the modulus M when the elastic body is stretched to 50% 50 A power supply unit characterized by having a pressure in the range of 0.3 MPa to 10 MPa.

2. The inner surface area Ea [mm²] of the elastic body 2 ] and the outer surface area Pa [mm²] of the unit body 2 The power supply unit according to claim 1, characterized in that the relationship between ] and 0.4 ≤ Ea / Pa.

3. The elongation EB [%] at break of the elastic material at 20°C and the modulus M of the elastic material when stretched to 100%. 100 The power supply unit according to claim 1 or 2, characterized in that [MPa] and the relationship shown in formula (1) below are satisfied. 1000≧275×M 100 -EB ・・・(1)

4. The module body comprises an integrated power receiving unit for receiving power, a power storage unit for storing the received power, and electronic components including a sensor element for detecting tire information, and at least a portion of this module body is housed in an elastic body, wherein the modulus M when the elastic body is stretched to 50% 50 A sensor module characterized by having a pressure range of 0.3 MPa to 10 MPa.

5. The inner surface area Ea [mm²] of the elastic body 2 ] and the outer surface area Ma [mm²] of the module body 2 The sensor module according to claim 4, characterized in that the relationship between ] and 0.5 ≤ Ea / Ma is satisfied.

6. The elongation at break EB [%] of the elastomer at 20°C and the modulus M at 100% elongation of the elastomer 100 [MPa] satisfy the relationship of the following formula (1), and the sensor module according to claim 4 or 5, characterized in that. 1000≧275×M 100 -EB ・・・(1)

7. A tire having a power supply unit according to claim 1 or 2 on its inner surface, wherein a reinforcing layer containing a plurality of steel cords is arranged, the power supply unit is arranged in a region of the inner surface of the tire corresponding to the area where the reinforcing layer is arranged, and in a front view of the reinforcing layer, the ratio of the area of ​​the portion excluding the steel cords to the area of ​​the reinforcing layer is in the range of 5% to 60%.

8. A tire having a sensor module according to claim 4 or 5 on its inner surface, wherein a reinforcing layer containing a plurality of steel cords is arranged, the sensor module is arranged in a region of the inner surface of the tire corresponding to the area where the reinforcing layer is arranged, and in a front view of the reinforcing layer, the ratio of the area of ​​the portion excluding the steel cords to the area of ​​the reinforcing layer is in the range of 5% to 60%.

9. A tire comprising the power supply unit according to claim 1 or 2, characterized in that the power receiving unit is arranged parallel to the inner surface of the tire.

10. A tire comprising the sensor module according to claim 4 or 5, characterized in that the power receiving unit is arranged parallel to the inner surface of the tire.

11. A wireless power supply system comprising: a tire having a power supply unit according to claim 1 or a sensor module according to claim 4 on its inner surface; a power receiving circuit unit disposed as a power receiving unit of the power supply unit or the sensor module and receiving power wirelessly; and a power supply device including a power supply circuit unit that wirelessly supplies power to the power receiving unit, The power supply circuit section includes at least a power supply coil that generates magnetic flux, and supplies power to the power supply coil in order to generate magnetic flux. The power receiving circuit section includes at least a power receiving coil that receives the magnetic flux emitted from the power supply coil, and recovers the energy generated in the power receiving coil by electromagnetic induction. The power supply circuit section includes a power supply side resonant capacitor that forms a parallel resonant circuit in combination with the power supply coil so as to resonate at a predetermined resonant period, a switch circuit that realizes an on state in which a drive current flows to the power supply coil and a switch off state in which the drive current is cut off, and a control circuit that inputs a drive pulse signal to control the on and off states to the switch circuit and adjusts the timing of inputting the drive pulse signal. The power receiving circuit section has a power receiving side resonant capacitor that forms a resonant circuit in combination with the power receiving coil so as to resonate at a predetermined resonant period. A wireless power supply system characterized in that, when the power supply device is installed in close proximity to a part of the tire and the power receiving unit is located within the power supply range of the power supply device, the system further includes a frequency adjustment circuit that appropriately controls the distance between the power receiving unit and the power supply device by appropriately fine-tuning the capacitance of the resonant capacitor on the power supply side or the inductance of the power supply coil with respect to the distance between the power receiving unit and the power supply device, and by fine-tuning the resonant period of the power supply device at the timing of inputting the drive pulse signal.

12. The wireless power supply system according to claim 11, characterized in that magnetic flux passes through the steel cords of the reinforcing layer embedded in the tire by coupling obtained by adjusting the size, number of turns, and inductance of the power supply coil and the power receiving coil so that the coupling coefficient K between the power supply coil and the power receiving coil is in the range of K = 0.3 or less.

13. The power supply circuit section includes a current measurement circuit and a voltage sensor for measuring the current flowing through the power supply coil, the tire is in a rotating state, the power supply device is installed in close proximity to a part of the tire, the current measurement circuit measures the change in current, the voltage sensor measures the change in voltage, and this measured information is input to the control circuit. The wireless power supply system according to claim 11, characterized in that when the power receiving unit enters the power supply range of the power supply device due to the rotation of the tire, the control circuit has a function to notify by predetermined communication means or by light or sound when it senses that the power receiving unit is within the power supply range of the power supply device based on the change in the current value of the current measurement circuit and the change in the voltage value of the voltage sensor.

14. The power supply circuit section includes a current measurement circuit and a voltage sensor for measuring the current flowing through the power supply coil, the power supply device is in a state where it is rotating around the outer circumference of the tire, the power supply device is installed in a location close to a part of the tire, the current measurement circuit measures the change in current, the voltage sensor measures the change in voltage, and this measured information is input to the control circuit. The wireless power supply system according to claim 11, characterized in that when the power supply device rotates around the outer circumference of the tire, causing the power receiving unit to enter the power supply range of the power supply device, the control circuit has a function to notify by predetermined communication means or by light or sound when it senses that the power receiving unit is within the power supply range of the power supply device based on the change in the current value of the current measurement circuit and the change in the voltage value of the voltage sensor.

15. The power supply circuit section includes a current measurement circuit and a voltage sensor for measuring the current flowing through the power supply coil, the power supply device is installed in a location close to a part of the tire, the current measurement circuit measures the change in current, the voltage sensor measures the change in voltage, and this measured information is input to the control circuit. The wireless power supply system according to claim 11, characterized in that when the tire enters the power supply range of the power supply device, the control circuit detects energy loss due to the steel cords of the reinforcing layer embedded in the tire based on changes in the current value of the current measurement circuit and the voltage value of the voltage sensor, and when it senses that the tire is in a predetermined position, it has a function to notify by predetermined communication means or by light or sound.

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