JPH09300928A - Reading and writing method for transponder mounted on wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the performance and durability of a transponder without having influence on a tire, by reading and writing form the outside of a wheel from/to the transponder which is arranged in the air filling chamber of a pneumatic tire and whose circumference is coated with a cushioning. SOLUTION: In a wheel, a transponder 6 whose circumference is coated with a cushioning 5, is stored under nonrestraint in an air filling chamber 4 surrounded by a tire 1 and a rim 3. Rubber and the like is used for the cushioning 5, and the cushioning 5 is formed in a spherical shape. Then, when read-write is executed to the transponder 6, a vehicle is stopped, and the transponder 6 is positioned on the road surface side of a tire inner wall by gravity. Then, a reading/writing device is arranged in a predetermined range from a tire grounding part so as to be accessed to the transponder 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading and writing method for a transponder which transmits various information regarding a tire.

[0002]

2. Description of the Related Art The basic technology of a transponder, which has the functions of both a receiver and a transmitter, has already been established and is now applied in various fields. One of them is application to a tire, and a transponder is used to obtain information for identifying the tire or information such as the tire internal pressure, temperature, and rotation speed. For example, from a position remote from the tire, a radio wave from a reading / writing device (hereinafter referred to as a reading / writing device) is applied to a transponder embedded in the tire to generate an electric induction signal in the transponder to activate the transponder. A technique for receiving an information signal from the transponder is disclosed in Japanese Utility Model Publication No. 2-123404.

This transponder is a relatively small one mainly composed of an integrated circuit and a coil, and an outer shell that protects the coil. The transponder has various shapes such as a coin shape and a cylindrical shape. As the embedding position, the carcass ply outer end surface of the carcass ply roll-up portion or the buttress portion (the tire radial outer end of the sidewall portion) is shown.

[0004]

When embedding a transponder in a tire, the transponder becomes a foreign substance in terms of the performance of the tire and induces separation, so that the durability of the tire deteriorates due to the transponder. It is essential to avoid On the other hand, in the transponder which is an electronic component, the internal environment of the tire is harsh, and it is important that the failure is not induced by an external force received through the tire or heat generated in the tire.

That is, the information from the transponder is
For example, it is extremely advantageous in managing the tire, but since the performance of the tire does not exceed the subordinate characteristics, embedding the transponder impairs the durability of the tire becomes a serious problem.

Therefore, it is essential to establish communication with the transponder while the transponder does not adversely affect the durability of the tire and the transponder is protected from the severe environment in which the tire is used.

[0007]

DISCLOSURE OF THE INVENTION The inventors have found that the structure in which a transponder is buried in a tire cannot completely prevent the transponder from becoming a foreign matter in the tire even if the buried position is strictly defined. From this, when the advantageous mounting method of the transponder was investigated without being confined to the built-in tire, the present invention was completed.

That is, according to the present invention, a transponder whose periphery is covered with a cushioning material is unconstrainedly housed in an air-filled chamber surrounded by a pneumatic tire of a wheel in which a pneumatic tire is assembled to a wheel and a rim of the wheel. However, the reading and writing method for the transponder is characterized by reading and writing from the outside of the wheel.

Here, it is advantageous in practice that reading and writing are performed when the wheel is stopped, that the cushioning material is rubber, and that the outer shape of the cushioning material is spherical.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The method of the present invention is characterized by reading and writing to a transponder contained unconstrained in an air-filled chamber surrounded by a pneumatic tire of a wheel and a rim of a wheel. There is. That is, as shown in FIG. 1, the tire 1 is attached to the rim 3 of the wheel 2.
It is essential that the transponder 6 whose periphery is covered with the cushioning material 5 is unconstrained and housed in the air-filled chamber 4 surrounded by the tire 1 and the rim 3 in the wheel that is assembled to. In the tire 1, 7 is a bead core, 8 is a carcass ply wound around the bead core 7, 9 is a belt, and 10 is a tread.

Since the transponder 6 mounted on the wheels as described above is unrestrained, the transponder 6 is always positioned on the road surface side of the inner wall of the tire due to gravity when the vehicle is stopped. Therefore, when the vehicle stops, the position of the transponder 6 is determined. Therefore, if the read / write device is arranged around the ground contact portion of the tire, the transponder 6 can be almost certainly accessed. As the read / write device for transmitting / receiving a signal to / from the transponder, for example, those described in Japanese Patent Publication No. 501939/1992, US Pat. No. 5181975, etc. are advantageously applicable.

By the way, since the reaching distance of the radio wave acting on the transponder at the time of access is as short as less than 1 m, it is preferable to access after knowing the position of the transponder in a large tire for trucks and buses, for example. Therefore, it is preferable to access after understanding the position of the transponder. Therefore, it can be said that the method of the present invention in which the position of the transponder is almost constant is particularly suitable for large tires for trucks and buses.

Further, since the transponder 6 is housed in the air-filled chamber 4, the existence of the transponder 6 is not known from the outside of the wheel, which is useful for theft prevention. That is, writing the serial number etc. stamped at the time of tire manufacturing on the transponder and reading this will allow the tire to be identified at all times. This makes it possible to check whether the tires attached to the rented vehicle are installed and prevent theft of the tires.

As shown in FIG. 2, the transponder 6 includes a package 11 containing an integrated circuit and a rod antenna 12 containing a ferrite core, a cylindrical glass container 13 and a rod antenna 12.
It is generally housed in. Since the heat resistance limit of this type of transponder is usually about 60 to 80 ° C., the heat resistance limit is exceeded inside the tire and in the vicinity of the axle, and the frequency of failure has conventionally been high. On the other hand, according to the present invention, by housing the transponder 6 whose periphery is covered with the cushioning material 5 in the air-filled chamber 4, the transponder 6 is separated from the axle, so that the temperature exceeding the heat resistance limit is not reached. Moreover, since the transponder is not built in the tire, the durability or performance of the tire is not impaired.

As the cushioning material 5 for covering the transponder 6, a material excellent in impact absorption especially during wheel rotation during traveling of the vehicle, such as rubber, polyphenylene sulfide (PPS), polybutylene terephthalate (PBT) is used. ), Polyethylene terephthalate (PET),
A synthetic resin such as ABS resin is suitable, but other materials may be used as long as they have appropriate shock absorption, heat insulation, mechanical strength and moldability.

Further, the outer shape of the cushioning material 5 is not particularly limited as long as the transponder rolls on the inner wall of the tire with a low resistance during rotation of the tire, but as shown in a typical example in FIG. It is preferably spherical, such as spindle-shaped. That is, by making the outer shape of the cushioning material 5 spherical and forming a curved surface, the rolling resistance is reduced,
As a result, rolling noise of the transponder during tire rotation can be reduced.

In FIG. 1 or 3, the transponder of the type shown in FIG. 2, that is, an electric induction signal is generated in the transponder by a radio wave from the outside of the transponder to activate the transponder to transmit an information signal. Although the so-called passive type is shown, for example, as shown in FIG.
It is also possible to apply a so-called active type transponder to which a power source and sensors are attached to the present invention.

That is, in the active transponder shown in FIG. 4, a package 11 containing an integrated circuit and an antenna, a pressure sensor 15, a temperature sensor 16 and a battery 17 are arranged on a substrate 14, and these are placed in a container 18. The container 18 is housed, and the container 18 is covered with a spherical cushioning material 5. Also, reference numeral 19
Is a conduit that connects the pressure sensor 15 to the outside, and guides external pressure to the pressure sensor 15 through the conduit opening 19A to measure the pressure. This conduit 19 can be formed by means such as filling the pipe to form the conduit 19 when the buffer material 5 is coated. The temperature sensor 16
Since it suffices to measure the heat from the outside that is transmitted through the cushioning material 5 and the container 18, it is not necessary to make a connection with the outside.

The pressure sensor 15 is used to measure the internal pressure of the tire before and during running, and the temperature sensor 16 is used mainly to measure the tire temperature during running.
If these data are abnormal, the transponder can issue an alarm. The integrated circuit built in the package 11 consists of a pressure sensor 15 and a temperature sensor 16.
Functions such as recording information from the vehicle, responding to signals from the read / write device, performing two-way communication of identification information regarding the tire with the read / write device, and issuing an alarm. preferable.

This active type transponder is larger than the passive type, but since the air-filled chamber 4 for accommodating the transponder is a relatively large space, it is possible to accommodate the active type transponder. .

[0021]

According to the present invention, various information can be read from and written to the transponder while ensuring the performance and durability of the transponder without sacrificing the performance of the tire.

[Brief description of drawings]

FIG. 1 is a diagram showing a wheel equipped with a transponder.

FIG. 2 is a diagram showing the structure of a passive transponder.

FIG. 3 shows a passive transponder.

FIG. 4 is a diagram showing an active transponder.

[Explanation of symbols]

 1 tire 2 wheel 3 rim 4 air filling chamber 5 cushioning material 6 transponder 7 bead core 8 carcass ply 9 belt 10 tread 11 package 12 rod antenna 13 glass container 14 substrate 15 pressure sensor 16 temperature sensor 17 battery 18 container

Claims (4)

[Claims] 1. A transponder, the circumference of which is covered with a cushioning material, is unconstrainedly housed in an air-filled chamber surrounded by a pneumatic tire of a wheel having a pneumatic tire mounted on a wheel and a rim of the wheel. A reading and writing method for a transponder mounted on a wheel, wherein reading and writing are performed from the outside of the wheel. 2. The method according to claim 1, wherein reading and writing are performed when the wheel is stationary. 3. The method according to claim 1, wherein the cushioning material is rubber. 4. The outer shape of the cushioning material is spherical.
Or the method of 3.