JP2002264617A - Structure for installing rfid tag on tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for installing an RFID tag on a tire enabling communication with the internal RFID tag from any directions throughout the circumference of the tire by way of the action of a loop antenna, while making it possible to increase the distance of the communication and easily read from the outside the value detected by an internal state detecting part installed inside the tire. SOLUTION: The loop antenna 8 is provided along the circumferential direction of the tire 7, and the RFID tag 1a having both a detection coil 9a forming a series circuit with the loop antenna and an antenna coil 2a electromagnetically coupled to the coil 9a is provided within the tire 7. Further, the internal state detecting part 11 for detecting air pressure and internal temperature or the like is provided inside the tire 7 and the tag 1a is connected thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting an RFID tag having an antenna coil and a control unit on a tire of an automobile or the like.

[0002]

2. Description of the Related Art Tires for vehicles such as automobiles are required to store unique information and history information of each tire such as its type, serial number, type of vehicle used, characteristics, and the like in production management, shipping and distribution management, and maintenance management. Need to know quickly.

[0003] In particular, due to the conversion from conventional fault liability to zero fault liability under the Product Liability (PL) Law, which came into effect on July 1, 1995, it is a problem whether or not the manufacturer is negligible. And the existence of product defects has become a problem, and the International Organization for Standardization (ISO;
International Organization for Standardization) is one of the ISO9000 series of quality assurance established by the International Organization for Standardization, and is a certification of the ISO9001 standard that is applied when products are designed, developed, manufactured, installed, and ancillary services are consistently performed by producers. In the case of obtaining a product, whether or not a reliable quality assurance system from the customer's point of view has been established for products and services is subject to examination, the design and development of products and parts from manufacturing Various information managements such as installation, ancillary services, and the like are being demanded.

[0004] Therefore, it is desirable that such information be easily comprehended from the viewpoint of measures against the PL law and the acquisition of ISO standard certification. The method of storing the tire information separately from the tire has a low utility value, and thus it is desirable to add the tire information to a part of the tire.

[0005] Further, if tire-specific information is added to tires, vehicle management (for example, vehicle entrance / exit management in a parking lot).
Can be used for

As a method of adding such information to a tire, a method of sticking or engraving the information on a tire side surface or the like in the form of a bar code has been proposed.

[0007]

However, in the engraving, the amount of information is limited by the display surface area and may disappear due to wear. Barcodes have not been put into practical use due to problems such as a small information capacity and inability to be read due to contamination or wear due to a severe use environment.

On the other hand, an RFID which stores a large amount of information and can read the information from outside without contact
A tag (Radio Frequency IDentification TAG) is known and is used in various fields.

Therefore, it is conceivable to install the RFID tag inside the tire and read out the information from the outside using an electromagnetic wave.

However, since the communicable distance of the RFID tag is generally several millimeters to several centimeters, it is difficult to set the detection position when the RFID tag is installed in a part of a tire, and the RFID tag cannot be put to practical use as it is. Absent.

[0011] Further, if there is a system that informs the driver's seat of information on the internal state of the tire, such as the tire pressure and internal temperature, and alerts the driver, the system can be used for driving management and prevent accidents. It is desirable from the point of view.

However, a technique for remotely transmitting information in a tire rotating at a high speed to a driver's seat or the like has not been known so far.

The present invention has been made to solve the above problems, and
The purpose is to provide a loop antenna along the circumferential direction of the tire, and provide a detection coil constituting a series circuit in the loop antenna and an RFID tag having an antenna coil electromagnetically coupled to the detection coil in the tire. This allows the loop antenna to communicate with the internal RFID tag in any direction over the entire circumference of the tire from any direction, thereby increasing the communication distance, and further reducing the air pressure and internal temperature inside the tire. By installing an internal state detection unit for detection and connecting it to an RFID tag, the detected value can be easily read from the outside to the RFID on the tire.
It does not provide a tag installation structure.

[0014]

According to the present invention, there is provided a structure for mounting an RFID tag on a tire according to the present invention.
An RFID tag and a detection coil electromagnetically coupled to an antenna coil of the RFID tag are provided inside the tire, and a loop antenna is provided along a circumferential direction of the tire, and the detection coil and the loop antenna are connected in series. It is characterized by constituting a circuit.

Since the present invention is constructed as described above, a loop antenna is provided along the circumferential direction of the tire, and has a detection coil constituting a series circuit, and an antenna coil electromagnetically coupled to the detection coil. Since the RFID tag is provided in the tire, the RFID inside the tire from any direction over the entire circumference of the tire by the action of the loop antenna.
Communication with the tag is possible, the communication distance can be lengthened, and communication can be made with the driver's seat or the like even when the tire is rotating at a high speed such as when driving a vehicle.

That is, when an external read / write terminal
When reading the unique information stored in the FID tag, the information is transmitted from the antenna coil of the RFID tag as a change in magnetic flux to the detection coil.

Then, a current corresponding to the change in the magnetic flux flows through the detection coil, and the current also simultaneously flows through the loop antenna forming a series circuit with the detection coil, thereby causing a change in the magnetic flux over the entire circumference of the tire. Therefore, the information can be read by the read / write terminal or the like from all directions outside the tire.

Conversely, when transmitting power or information from a read / write terminal to an RFID tag, a change in magnetic flux caused by a signal transmitted from an antenna of the read / write terminal or the like is first detected by a loop antenna, and thereby a loop antenna is used. Then, the detection coil amplifies it in the form of magnetic flux (amplification by the number of turns), and the antenna coil of the RFID tag detects the change in the amplified magnetic flux.

Since communication is possible from all directions,
Even when the tire is rotating at a high speed, such as when driving a vehicle, R
The FID tag information can be displayed on, for example, an operation panel provided in a driver's seat.

The loop antenna can be embedded in the tire or fixed along the inner peripheral surface of the tire.

Further, it is preferable that the tire is a steel tire provided with steel along the circumferential direction of the tire, and at least one of the steels also serves as the loop antenna.

In addition, a concentric disk-shaped antenna coil provided on the RFID tag and a circular detection coil are electromagnetically coupled to each other, or a cylindrical antenna coil provided on the RFID tag, It is preferable that the cylindrical detection coil is electromagnetically coupled to the detection coil.

Also, a case is provided in which an internal state detecting section provided in the tire is connected to the RFID tag, and a detection value detected by the internal state detecting section can be read out from the outside via the RFID tag. In, the detection value detected by the internal state detection unit can be read from the outside and the information in the tire can be notified to the driver's seat or the like.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the structure for mounting an RFID tag on a tire according to the present invention will be specifically described with reference to the drawings. FIG. 1A is a sectional explanatory view showing a first embodiment of a structure for mounting an RFID tag on a tire according to the present invention, and FIG.
FIG. 2B is an explanatory side view showing a first embodiment of a structure for mounting an RFID tag on a tire according to the present invention, and FIG. 2A is a second embodiment of a structure for mounting an RFID tag on a tire according to the present invention. FIG. 2B is an explanatory side view showing a second embodiment of a structure for mounting an RFID tag on a tire according to the present invention.

FIG. 3 is a diagram showing a state in which a cylindrical antenna coil and a cylindrical detection coil are electromagnetically coupled, and FIG. 4 is a diagram in which a concentric disk-shaped antenna coil and a circular detection coil are electromagnetically coupled. FIG.

FIG. 5 is an explanatory front view showing the configuration of an RFID tag having a cylindrical antenna coil, and FIG. 6 is a schematic diagram showing the state of a magnetic field generated in the RFID tag having a cylindrical antenna coil.

FIG. 7 is an explanatory front and side view showing the structure of an RFID tag having a concentric disk-shaped antenna coil.
FIG. 3 is a schematic diagram showing a state of a magnetic field generated in an RFID tag having a concentric disk-shaped antenna coil.

FIG. 9 is a block diagram showing a configuration of a control system of the RFID tag, and FIG. 10 is a block diagram of a control system when an internal state detecting unit provided in the tire is connected to the RFID tag.

The RF preferably employed in each of the following embodiments
The ID tags 1a and 1b are RFID tags of an electromagnetic coupling type or an electromagnetic induction type, and both can communicate with a read / write terminal or the like without using an electromagnetic wave. In the following embodiments, an embodiment in which an electromagnetic induction type RFID tag is used will be described below.

Generally, the RFID tags 1a and 1b have antenna coils 2a and 2b and a semiconductor IC chip 4 serving as a control unit. When the antenna coils 2a and 2b receive a transmission signal from an external read / write terminal (not shown) or the like. The control unit accumulates the electric power in the capacitor 4d as electric power, and uses the electric power to store the information such as the ID code stored in the memory 4b as the storage unit again into the antenna coils 2a, 2d.
2b to the read / write terminal.

As a transmission / reception system, amplitude shift keying using one wave (ASK system: Amplitude Shift Keying system)
And frequency shift keying using two waves (FSK: Frequenc
y Shift Keying method), the former performs transmission and reception by intensity modulation of electromagnetic waves, and the latter performs transmission and reception by frequency modulation of electromagnetic waves.

When a general RFID tag is divided into antenna coil types, a cylindrical antenna coil 2a in which an insulated copper wire such as an enamel wire is wound around a core member 3 such as a rod-shaped ferrite core, and a circular air core coil are used. There are two types, that is, a concentric disk-shaped antenna coil 2b, and the outer shape is formed in a rod shape, and the latter is formed in a disk shape according to the shape of each antenna coil 2a, 2b.

The RFID tag 1a having the cylindrical antenna coil 2a performs communication by utilizing the change in the magnetic flux in the axial direction, and the RFID tag 1a having the concentric disk-shaped antenna coil 2b.
The FID tag 1b performs communication using a change in magnetic flux in the surface direction of the circular coil. In the present invention, any of these cylindrical and disk-shaped RFID tags 1a and 1b can be used.

In the RFID tag 1a shown in FIG. 5, a cylindrical antenna coil 2a and a semiconductor IC chip 4 serving as a control unit are directly connected without a printed circuit board or the like, and are integrally formed. As a result, the size of the RFID tag 1a is reduced.

A cylindrical core member 3 such as an iron core or ferrite is inserted in an axial direction (left and right direction in FIG. 5) inside an antenna coil 2a formed in a single wire winding into a cylindrical shape. The core member 3, the semiconductor IC chip 4, and the like are integrally formed, and the whole is configured in a rod shape.

The semiconductor IC chip 4 is formed by integrally packaging an IC (semiconductor integrated circuit) chip, an LSI (semiconductor large scale integrated circuit) chip, or the like. As shown in FIG. 9, a CPU 4a serving as a control unit, a memory 4b serving as a storage unit, a transceiver 4c, and a capacitor 4d serving as power storage means are provided.

A signal transmitted from an external reader / writer terminal (not shown) is transmitted to a CPU 4a via a transceiver 4c.
And the power is stored in the capacitor 4d. still,
There may be no capacitor 4d serving as power storage means, and power may be continuously supplied to the semiconductor IC chip 4 from an external reader / writer terminal.

The CPU 4a is a central processing unit that reads out programs and various data stored in the memory 4b, performs necessary calculations and judgments, and performs various controls.

The memory 4b stores various programs for operating the CPU 4a, and various information such as history data and lot management data on the tire on which the RFID tags 1a and 1b are installed. The detection value detected by the state detection unit 11 is stored as needed.

The RFID tags 1a and 1b according to the present embodiment
Amplitude shift keying (ASK; Amplitude Sh
CMOS with very low power consumption incorporating a special transmitting / receiving circuit using antenna coils 2a and 2b having an air core or core member 3 having a wide resonance frequency band and a wire diameter of several tens of microns using a wireless communication system of "ift Keying". -Adopted RFID tags 1a and 1b using IC.

As shown in FIG. 5, the RFID tag 1a
Outer diameter D of the antenna coil 2a in the radial direction _TwoOuter diameter D according to₁To
Glass made of a glass material to be a non-conductive material
The container 5 is sealed and the entire periphery is covered.

The axial length L ₁ of the RFID tag 1a glass vessel 5 employed in this embodiment is about 7Mm～15.7Mm, the outer diameter D ₁ is about 2.12Mm～4.12Mm. The weight of the RFID tag 1a is 55 mg to 400 mg.
It is about mg.

The length L ₁ and outer diameter D ₁ of the glass container 5 in the axial direction of the RFID tag 1a and the length L ₂ and outer diameter D ₂ of the antenna coil 2a in the axial direction employed in this embodiment will be described below. An example is shown.

[0044]

[Table 1]

As an example of the antenna coil 2a, for example, a copper wire having a diameter of about 30 μm is wound in a single wire and is wound in a multilayer shape in the radial direction in a cylindrical shape in the axial direction, and the core member 3 is provided inside the antenna coil 2a. In this state, the inductance was about 9.5 mH (frequency 125 kHz), and the capacitance of a capacitor separately connected to the antenna coil 2a for resonance was about 170 pF (frequency 125 kHz).

FIG. 6 shows a state of a magnetic field H generated from the RFID tag 1a in a free state.

The RFID tag 1b shown in FIG. 7 also includes a concentric disk-shaped antenna coil 2b and a semiconductor
The C chip 4 is directly connected to the C chip 4 without a printed circuit board or the like, and is integrally formed.
Has been downsized. The configuration of the control system of the RFID tag 1b is the same as that shown in FIG. 9 and described above.

The inside of the RFID tag 1b shown in FIG.
An antenna coil 2b and a semiconductor IC chip 4 which are formed in a concentric disk shape by forming a multilayer in the radial direction by a single wire winding
And the like are integrally sealed with a resin 6 to form a disk-like structure as a whole.

[0049] RFID tag 1b is sealed with a resin 6 having an outer diameter D ₃ corresponding to the outer diameter D ₄ in the radial direction of the antenna coil 2b.

An example of the outer diameter D ₃ of the resin 6 of the RFID tag 1b, the outer diameter D ₄ of the antenna coil 2b, and the inner diameter D ₅ of the antenna coil 2b employed in the present embodiment are shown below.

[0051]

[Table 2]

The thickness T of the resin 6 of the RFID tag 1b
Is about 0.7 mm to 12.0 mm, and the RFID tag 1b
Weighs about 0.7 g to 5.2 g.

As an example of the antenna coil 2b, a copper wire having a diameter of about 30 μm is wound concentrically in a single-layer winding and in a radial direction in a multi-layered manner.
Had an inductance of about 9.5 mH (frequency 125 kHz), and the capacitance of a capacitor separately connected to the antenna coil 2b for resonance was about 170 pF (frequency 125 kHz).

FIG. 8 shows the state of the magnetic field H generated from the RFID tag 1b in a free state.

In FIG. 1, an RFID tag 1a having a cylindrical antenna coil 2a is installed inside a rubber tire 7 of an automobile or the like on the grounding surface side, and the tire 7 is contacted along the circumferential direction of the tire 7. A large-diameter loop antenna 8 is embedded all around the ground side inside.

The tire 7 shown in FIG. 1 has steel 10 such as tire cords inside the tire 7 along the circumferential direction of the tire 7.
Is a buried steel tire, and at least one of the steel tires 10 may also serve as the loop antenna 8.

As shown in FIG. 3, the loop antenna 8 forms a series circuit with a small-diameter cylindrical detection coil 9a.
The detection coil 9a is wound around the outer periphery of the glass container 6 along the core member 3 inserted into the antenna coil 2a of the RFID tag 1a, and is fixed by an adhesive or the like in a state of being electromagnetically coupled. 1a and detection coil 9a
Are integrally fixed to the tire 7 with an adhesive or the like.

In FIG. 2, an RFID tag 1 b having a concentric disk-shaped antenna coil 2 b is installed inside the side surface of the tire 7, and has a large diameter along the entire circumference inside the side surface of the tire 7 along the circumferential direction of the tire 7. Loop antenna 8 is embedded.

As shown in FIG. 4, the loop antenna 8 forms a series circuit with a small-diameter, circular detection coil 9b, and the detection coil 9b is formed on the antenna coil 2b of the RFID tag 1b via an insulating film or sheet. The RFID tag 1b and the detection coil 9b are integrally fixed to the tire 7 by an adhesive or the like while being in contact with the electromagnetic wave and electromagnetically coupled.

Although FIG. 1 and FIG. 2 are schematically shown for easy explanation and understanding, the actual R
The FID tags 1a, 1b and the detection coils 9a, 9b are extremely small as compared with the tire 7, are fixed to the tire 7 by bonding with an adhesive, and the protrusion into the tire 7 is minute. The tire 7 is fixed so as to sufficiently withstand the centrifugal force caused by the high-speed rotation of the tire 7.

Further, the RFID tags 1a and 1b and the detection coils 9a and 9b may be provided so as to be integrally embedded in the tire 7.

The detection coils 9a and 9b and the loop antenna 8
May be integrally formed, or may be formed separately and electrically connected as shown in FIGS. 3 and 4.

Although the RFID tags 1a and 1b are preferably fixed to the inner peripheral surface of the tire 7 by bonding or the like for ease of installation, the RFID tags 1a and 1b may be embedded in the tire 7 together with the loop antenna 8 and the detection coils 9a and 9b. good. These are tire 7
When buried in the inside of the tire 7, it is preferable to be integrally molded with the constituent material of the tire 7.

The loop antenna 8 is buried along the inner or inner peripheral portion of the tire 7 or is fixedly laid along the inner or inner peripheral surface by bonding or the like.

In the case of a steel tire, at least one of the reinforcing steels 10 can be formed in a continuous loop shape along the periphery, and can also be used as the loop antenna 8.

The loop antenna 8 may be at least one wire or tape made of a conductive metal material such as copper, but it is desired to further increase the communication sensitivity (to increase the communication distance). Sometimes it can be dealt with by winding several.

The detection coils 9a and 9b are the RFID tags 1
In order to perform electromagnetic coupling with the antenna coils 2a and 2b of the antenna coils a and 1b, the antenna coils 2a and 2b are adapted to the shapes of the antenna coils 2a and 2b. That is, in the case of the cylindrical antenna coil 2a, the detection coil 9a has a cylindrical (tubular) shape. In the case of a concentric disk-shaped antenna coil 2b, a circular detection coil 9b is used.

Then, the detection coils 9a and 9b and the antenna coils 2a and 2b are brought close to each other, and a signal or electric power is transmitted by a change in magnetic flux linking the two coils. That is, transmission of signals and the like is performed by electromagnetic coupling. Note that the detection coils 9a,
To increase the communication sensitivity of 9b, the number of turns may be increased.

The detection coils 9a and 9b are connected to the loop antenna 8
May be installed close to the end of the tire 7 and buried and fixed inside the tire 7, or may be fixed to the inner peripheral surface or inner surface of the tire 7 by bonding or the like. Further, the detection coils 9a, 9b and R
The FID tags 1a and 1b can be structurally integrated with each other.

By providing such detection coils 9a and 9b, there is an advantage that the conventional RFID tag can be used as it is, and by increasing the number of turns of the detection coils 9a and 9b, the current flowing through the loop antenna 8 can be increased. Can increase the amount of magnetic flux generated as needed.

The memory 4b of the RFID tags 1a and 1b stores, in addition to the unique information of the tire 7, vehicle information on which the tire 7 is mounted, for example, a vehicle registration number (number of a license plate), an owner name, a card number, and the like. You can also memorize. Such vehicle information can also be used for, for example, management of parking and entering and exiting parking lots, management of truck operation, and the like.

For example, when reading unique information stored in the RFID tags 1a and 1b from an external read / write terminal or the like, the information is transmitted from the antenna coils 2a and 2b to the detection coils 9a and 9b as a change in magnetic flux.

Then, a current corresponding to the change in the magnetic flux flows through the detection coils 9a and 9b, and the current also simultaneously flows through the loop antenna 8 forming a series circuit with the current. Change occurs.

Therefore, information can be read from the read / write terminal or the like from all directions outside the tire 7. Conversely, power and information from a read / write terminal etc.
When transmitting to the antennas a and 1b, a change in magnetic flux caused by a signal transmitted from an antenna of a read / write terminal or the like is first captured by the loop antenna 8, whereby a current flows through the loop antenna 8, and this is detected by the detection coils 9a and 9b. Is amplified in the form of a magnetic flux (amplification by the number of turns), and the change in the amplified magnetic flux is reflected on the antenna coil 2 of the RFID tags 1a and 1b.
a and 2b capture.

As described above, since communication is possible from all directions, various kinds of information stored in the memory 4b of the RFID tags 1a and 1b can be stored in the driver's seat, for example, even when the tire 7 is rotating at a high speed such as when driving a vehicle. Can be displayed on an operation panel or the like provided in the.

FIG. 10 is a block diagram of a control system when the internal state detecting unit 11 provided in the tire 7 is connected to the RFID tags 1a and 1b. As shown in FIG. 10, the internal state detection unit 11 has an internal pressure detector using a magnetostrictive element or the like for detecting the air pressure in the tire 7, a temperature detector using a thermistor for detecting the temperature of the tire 7, and the like. A detector 12, an amplifier 13 for amplifying a detection signal of the detector 12, and an A for converting an analog signal detected by the detector 12 into a digital signal;
/ D converter 14 and the like.

Power for operating the amplifier 13 and the A / D converter 14 is supplied from the capacitor 4 d, the analog detection signal detected by the detector 12 is amplified by the amplifier 13, and the analog detection signal is digitalized by the A / D converter 14. The signal is converted into a signal and stored in the memory 4b.

The detection value detected by the internal state detector 11 stored in the memory 4b by an external read / write terminal or the like can be read from the outside via the RFID tags 1a and 1b.

Most of the current tires 7 are tubeless, and the internal pressure detector (such as a magnetostrictive element) and the temperature detector (such as a thermistor) of the tire 7 are simply fixed to the inner peripheral surface of the tire 7 by bonding or the like. Then, the state in the tire 7 can be accurately detected.

Further, the main body of the detector 12 can be embedded in the tire 7 so that only the detection probe is exposed on the inner peripheral surface of the tire 7.

When the capacitor 4d of the semiconductor IC chip 4 receives the power of the read signal from an external read / write terminal or the like and accumulates it instantaneously, the internal state detector 11 is activated by the power, and the detector 12 Signal 13
, And digitized by the A / D converter 14 and stored in the memory 4b. Then, it is read out to the outside by a read timing signal from the CPU 4a. This series of operations is completed in about several milliseconds.

[0082]

Since the present invention has the above-described structure and operation, a loop antenna is provided along the circumferential direction of the tire, and a detection coil forming a series circuit is electromagnetically coupled to the detection coil. R with an integrated antenna coil
By providing the FID tag in the tire, it is possible to communicate with the internal RFID tag from any direction over the entire circumference of the tire by the action of the loop antenna, and the communication distance can be lengthened. It is possible to communicate with the driver's seat even when the tires are rotating at high speed.

In the case where the internal state detecting section provided in the tire is connected to the RFID tag and the detection value detected by the internal state detecting section can be read out from the outside via the RFID tag, In addition, the detection value detected by the internal state detection unit can be read from the outside, and the information in the tire can be notified to the driver's seat or the like.

[Brief description of the drawings]

FIG. 1 (a) is a cross-sectional explanatory view showing a first embodiment of a structure for mounting an RFID tag on a tire according to the present invention, and FIG. 1 (b) is a first view of a structure for mounting an RFID tag on a tire according to the present invention.
It is a side explanatory view showing an embodiment.

FIG. 2A is a cross-sectional explanatory view showing a second embodiment of a structure for mounting an RFID tag on a tire according to the present invention, and FIG. 2B is a second view showing a second structure for mounting an RFID tag on a tire according to the present invention;
It is a side explanatory view showing an embodiment.

FIG. 3 is a diagram showing a state in which a cylindrical antenna coil and a cylindrical detection coil are electromagnetically coupled.

FIG. 4 is a diagram showing a state in which a concentric disk-shaped antenna coil and a circular detection coil are electromagnetically coupled.

FIG. 5 is an RFID having a cylindrical antenna coil.
FIG. 3 is an explanatory front view showing the configuration of the tag.

FIG. 6 shows an RFID having a cylindrical antenna coil.
FIG. 3 is a schematic diagram illustrating a state of a magnetic field generated in a tag.

FIG. 7 is an RFID having a concentric disk-shaped antenna coil.
It is a front and side explanatory view showing the configuration of a tag.

FIG. 8 shows an RFID having a concentric disk-shaped antenna coil.
FIG. 3 is a schematic diagram illustrating a state of a magnetic field generated in a tag.

FIG. 9 is a block diagram illustrating a configuration of a control system of the RFID tag.

FIG. 10 shows that the internal state detection unit provided in the tire is RFI.
FIG. 3 is a block diagram of a control system when connected to a D tag.

[Explanation of symbols]

 1a, 1b RFID tag 2a, 2b Antenna coil 3 Core member 4 Semiconductor IC chip 4a CPU 4b Memory 4c Transceiver 4d Capacitor 5 Glass container 6 Resin 7 Tire 8 Loop antenna 9a 9b ... Detection coil 10 ... Steel 11 ... Internal state detector 12 ... Detector 13 ... Amplifier 14 ... A / D converter

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60C 23/20 B60C 23/20 H04B 5/02 H04B 5/02 (72) Inventor Tomoki Uchiyama Shinjuku-ku, Tokyo 1-22-2 Nishi Shinjuku Haneda Hume Tube Co., Ltd. F-term (reference) 5K012 AB05 AC06 AE01

Claims (5)

[Claims] An RFID tag inside a tire and the RFI
A detection coil electromagnetically coupled to the antenna coil of the D tag is provided, and a loop antenna is provided along the circumferential direction of the tire, and the detection coil and the loop antenna form a series circuit. Characteristic structure of mounting RFID tags on tires. 2. The RFI to a tire according to claim 1, wherein the loop antenna is embedded in the tire or fixed along an inner peripheral surface of the tire.
Installation structure of D tag. 3. The tire according to claim 1, wherein the tire is a steel tire provided with steel along a circumferential direction of the tire, and at least one of the steels also serves as the loop antenna. Installation structure of the RFID tag. 4. A concentric disk-shaped antenna coil provided on the RFID tag and a circular detection coil are electromagnetically coupled to each other, or a cylindrical antenna coil provided on the RFID tag, The RFID for a tire according to any one of claims 1 to 3, wherein the cylindrical detection coil is electromagnetically coupled to the detection coil.
Tag installation structure. 5. An internal state detecting section provided in the tire is connected to the RFID tag, and a detection value detected by the internal state detecting section can be read from the outside via the RFID tag. Claims 1 to
4. The structure for mounting an RFID tag on a tire according to any one of the above items 4.