JP2003291615A - Tire air pressure detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire pressure detecting device capable of making a monitoring device having a small number of receiving antennas receive the data showing a tire condition properly even if the transmission intensity is weak and reducing the cost of the monitoring device. <P>SOLUTION: A receiving circuit 17 and a transmitting circuit 18 are arranged in sensor devices 14a to 14f, and the data received from other sensor devices 14a to 14f through the receiving circuit 17 are transferred through the transmitting circuit 18 by a CPU 25. Even if the data detected by any of the sensor devices 14a to 14f do not reach the monitoring device, therefore, the data detected by the sensor devices 14a to 14f are transferred by any one of or a plurality of sensor devices 14a to 14f and received by the monitoring device. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire pressure detecting device for detecting a tire condition including a tire pressure and transmitting the tire condition as a radio signal.

[0002]

2. Description of the Related Art Conventionally, a tire air pressure monitoring device for detecting a tire condition such as a tire air pressure and a temperature, and judging whether or not an abnormality has occurred in the tire based on the detected results to improve the safety of a vehicle. It has been known.

Such a tire pressure monitoring device includes a sensor device (tire pressure detection device) provided on a tire valve of a vehicle tire and a monitor device provided inside the vehicle. The sensor device modulates the detected air pressure and temperature data (tire condition) of each tire into a radio wave (radio signal) having a predetermined frequency and transmits the radio wave to the outside. Also,
The monitor device receives the radio signal transmitted from the sensor device by the receiving antenna, demodulates the radio signal into a pulse signal through the receiving circuit, and inputs the pulse signal to the microcomputer.
The microcomputer of the monitor device reads air pressure and temperature data based on the received pulse signal. When the microcomputer determines that the data is abnormal, the microcomputer operates, for example, a display provided on the instrument panel to notify the passenger to that effect.

[0004]

By the way, when such a tire air pressure monitoring device is installed in a large vehicle such as a truck or trailer having a large number of tires, a monitor device (reception antenna) is provided as compared with a case where it is installed in a passenger car. There are sensor devices whose distances are long. In that case, in order to preferably receive the wireless signal from the sensor device having a long distance by the monitor device, it is necessary to increase the number of the receiving antennas, for example, disposing the receiving antennas in the vicinity of each tire. There was a problem that the cost would be high. Therefore, in order to preferably receive the wireless signal in the monitor device without increasing the number of receiving antennas, the transmission intensity (radio wave intensity) of the wireless signal from the sensor device is increased,
It is considered that the wireless signal can be received in a wide range. However, since the tire air pressure monitoring device is positioned as a radio equipment (so-called weak radio station) in which radio waves to be transmitted (radiated) are extremely weak, an upper limit is set to the transmission intensity by the Radio Law.

The present invention has been made in view of the above circumstances, and an object of the present invention is to allow a monitor device having a small number of receiving antennas to preferably receive data indicating a tire condition even when the transmission intensity of a radio signal is weak. Accordingly, it is an object of the present invention to provide a tire air pressure detection device that can reduce the cost of the monitor device.

[0006]

In order to solve the above problems, the invention according to claim 1 discloses a tire condition detecting means for detecting a tire condition including at least tire pressure, and data indicating the tire condition. In a tire pressure detecting device including a transmitting unit that transmits (hereinafter, referred to as first data) as a wireless signal, a receiving unit that can receive a wireless signal transmitted from another tire pressure detecting device, and a received wireless signal. And a transfer means for transferring data indicating a tire condition of another tire (hereinafter referred to as second data) included in the above (1) as a wireless signal via the transmitting means.

According to a second aspect of the present invention, in the first aspect, there is provided a storage means capable of storing the second data, and the transfer means temporarily stores the received second data in the storage means. The point is to transfer.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the first data and the second data are provided with identification data attaching means for attaching their own identification data to the transmitting means. The main point is to transmit each data to which the identification data is added as a radio signal.

According to a fourth aspect of the present invention, in the third aspect, the transfer means determines whether the second data received by the reception means is provided with identification data other than itself, and the transfer means itself. If it is determined that the identification data is added, it is not transferred.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects, a random number generation means for generating a random number is provided, and the transfer means is based on the random number, and the storage means. The gist is to determine when to transfer the second data stored in the.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the tire pressure monitoring device 11 includes first to sixth sensor devices 14a to 14f integrally formed with tire valves of the first to sixth tires 13a to 13f of the vehicle 12, respectively, and the vehicle 1
2 and a monitor device 15 disposed in the inside. The first to sixth sensor devices 14a to 14f correspond to the tire pressure detection device. In this embodiment, the vehicle 12 is
For example, because it is a large vehicle such as a truck or trailer,
The tires 13a to 13f are provided at 6 places.

(Sensor device) First to sixth sensor devices 14
a to 14f have the same configuration. Therefore, the configuration of the first sensor device 14a will be specifically described below, and the other second to sixth sensor devices 14b to 14f will be described.
The duplicated description of the configuration will be omitted.

As shown in FIG. 2, the first sensor device 14a
Includes a receiving circuit 17, a transmitting circuit 18, a micro computer (hereinafter referred to as a microcomputer 19), an air pressure sensor 20, a temperature sensor 21, and an antenna 22. The receiving circuit 17 and the antenna 22 constitute a receiving means, and the transmitting circuit 18 and the antenna 22 constitute a transmitting means.

The air pressure sensor 20 is configured to detect the air pressure in the first tire 13a, and the microcomputer 1
9 is connected. Then, the air pressure sensor 20 outputs air pressure data indicating the detected air pressure to the microcomputer 19. Further, the temperature sensor 21 is configured to detect the temperature inside the first tire 13a and is connected to the microcomputer 19. Then, the temperature sensor 21 outputs temperature data indicating the detected temperature to the microcomputer 19. In addition,
In the present embodiment, the tire state detecting means is composed of the air pressure sensor 20 and the temperature sensor 21, and the air pressure inside the tire and the temperature inside the tire correspond to the tire state.

The transmission circuit 18 is connected to the microcomputer 19,
Various data output from the microcomputer 19 are modulated into radio signals (radio waves) of a predetermined frequency and transmitted to the outside. Further, the receiving circuit 17 is connected to the microcomputer 19, and when receiving a wireless signal from the outside, demodulates the signal into a pulse signal and inputs the pulse signal to the microcomputer 19. An antenna 22 is connected to the transmitting circuit 18 and the receiving circuit 17, and the antenna 2
2 is used for both transmission and reception.

The microcomputer 19 includes a CPU 25 and a ROM 2
6, a CPU unit including a RAM 27.
The ROM 26 stores various control programs for controlling the first sensor device 14a.
Further, in the ROM 26, the sensor devices 14a to 14f are included.
A unique ID code (identification data) is stored. R
The AM 27 temporarily stores and holds various data that are appropriately rewritten during the operation of the first sensor device 14a. The CPU 25 corresponds to a transfer unit, an identification data addition unit, a random number generation unit, and the RAM 27 corresponds to a storage unit.

Then, according to the detection control program stored in the ROM 26, the CPU 25 causes the predetermined intermittent cycle T
Air pressure data is input from the air pressure sensor 20 and temperature data is input from the temperature sensor 21 for each one. Also, the CPU 25
Applies the ID code to the air pressure data and the temperature data and outputs the data to the transmission circuit 18. In the following description, the data (air pressure data, temperature data, and ID code) detected by the air pressure sensor 20 and the temperature sensor 21 and output with the own ID code is referred to as “detection data D1”. Then, this detection data D1 is transmitted as a radio signal. In the detection data D1, the air pressure data and the temperature data indicating the tire condition correspond to the first data.

The first sensor device 14a receives a radio signal transmitted from another sensor device to the outside, and transmits the data (air pressure data, temperature data, ID code) included in the radio signal again as a radio signal ( It has a transfer function to transfer. That is, when the antenna 22 receives the radio signal and the demodulated pulse signal is input from the receiving circuit 17, the CPU 25 causes the data (pneumatic pressure data) included in the pulse signal based on the transfer control program stored in the ROM 26. , Temperature data and ID code) are temporarily stored in the RAM 27. After that, the same data is stored in ROM2
The ID code stored in No. 6 is added and the signal is transmitted as a radio signal via the transmission circuit 18.

In the following description, the receiving circuit 17
The data (air pressure data, temperature data, and ID code) input from is referred to as "reception data D2". Further, in the reception data D2, the air pressure data and the temperature data indicating the tire condition correspond to the second data. Also, CP
Since U25 attaches its own ID code to the reception data D2 and transmits it, the reception data D2 may include a single ID code or a plurality of ID codes.

By the way, the transmission timings of the detection data D1 (radio signals) in the six first to sixth sensor devices 14a to 14f provided in the vehicle 12 are set to be different as shown in FIG. , Data interference is prevented. Specifically, the transmission timings are shifted so that the detection data D1 is transmitted every time the predetermined time I elapses from the six sensor devices 14a to 14f. And in this embodiment, as shown in FIG.
As shown in, the cycle of the first sensor device 14a → the second sensor device 14b → ... → the sixth sensor device 14f is repeated, and the detection data D1 is transmitted from each of the sensor devices 14a-14f. The order in which the detection data D1 is transmitted can be changed as appropriate. In addition, in the present embodiment, the intermittent cycle T in each of the sensor devices 14a to 14f.
1 is set to about 6 minutes, and about 1 minute (= predetermined time I
Any one of the first to sixth sensor devices 14a to 14
The detection data D1 is transmitted from f.

The first to sixth sensor devices 14a to 14f
The transmission strength of the radio signal in the above, that is, the electric field strength of the transmission radio wave (the strength of the radio wave) is set to be weak enough to transmit / receive the radio signal to / from the sensor devices 14a to 14f of the adjacent tires 13a to 13f. . Specifically, in FIG. 1, the first sensor device 14a located at the left rear and the sixth sensor device 14f located at the left center can transmit and receive, and the sixth sensor device 14f at the left center and the front left The fifth sensor device 14e, which is located, is capable of transmitting and receiving. Further, the second sensor device 14b located at the right rear and the third sensor device 14c located at the right center can transmit and receive, and the third sensor device 14c at the right center and the fourth sensor device 14d located at the front right. Can be sent and received. In addition, the first sensor device 14a on the left rear and the second sensor device 14b on the right rear are also capable of transmitting and receiving, and the sixth sensor device in the left center.
The sensor device 14f and the third sensor device 14c at the center of the right are also capable of transmitting and receiving. Furthermore, the fifth sensor device 1 on the left front
4e and the fourth sensor device 14d on the front right are also capable of transmitting and receiving. The left and right are the left and right when the vehicle 12 is viewed in plan, and the front and rear are the front and rear of the vehicle 12.

(Monitoring Device 15) As shown in FIG. 1, the monitoring device 15 includes a receiving antenna 31, a receiving circuit 32, a microcomputer (hereinafter, referred to as a microcomputer 33), and a display 34.

In this embodiment, only one receiving antenna 31 is provided and is connected to the receiving circuit 32. The receiving antenna 31 is connected to the fourth sensor device 14d.
And the position where the wireless signal from the fifth sensor device 14e can be received. The reception circuit 32 demodulates the radio signal received by the reception antenna 31 into a pulse signal and outputs the air pressure data, the temperature data, and the ID code to the microcomputer 33.

The microcomputer 33 is a CPU, RO (not shown).
It is composed of a CPU unit including M and RAM. Further, the microcomputer 33 is provided with tires 13a to 13f.
The reference data of is stored in advance. This reference data is a value indicating a normal value such as the air pressure or temperature of the tires 13a to 13f, and is set within a predetermined range.
Then, the microcomputer 33 determines that the input air pressure data and the temperature data are normal if they are within the range of the reference data, and determines that they are abnormal if they are outside the range of the reference data, and outputs an operation signal to the display 34. Is output.

The display device 34 is provided in the interior of the vehicle 12 (for example, an instrument panel) and is an indicator that indicates when an abnormality occurs in the tires 13a to 13f. This display 34 is a microcomputer 33
, And displays based on the operation signal from the microcomputer 33.

Next, the first to sixth parts configured as described above
The operation of the sensor devices 14a to 14f will be described. In the following description, the case where the air pressure data and the temperature data detected by the first sensor device 14a are transferred to the sixth sensor device 14f and the fifth sensor device 14e and received by the monitor device 15 will be described as an example. .

The CPU 25 of the first sensor device 14a inputs the air pressure data and the temperature data from the air pressure sensor 20 and the temperature sensor 21 at the timing of the intermittent cycle T1 according to the detection control program. And ID for both data
A code is added and the detected data D1 is output to the transmission circuit 18. The transmission circuit 18 to which the detection data D1 is input
Modulates the detection data D1 into a radio signal having a predetermined frequency and transmits the radio signal to the outside.

Then, the sixth sensor device 14f capable of transmitting and receiving to and from the first sensor device 14a receives the radio signal transmitted from 14a by the antenna 22. Then, the reception circuit 17 of the sixth sensor device 14f demodulates the radio signal input via the antenna 22 and inputs the demodulated radio signal to the microcomputer 19. As a result, the detection data D1 included in the wireless signal is input to the microcomputer 19 as the reception data D2. Microcomputer 19
The CPU 25 processes the received data D2 according to the transfer control program. The process for the received data D2 will be described below with reference to the flowchart shown in FIG.

In the sixth sensor device 14f, the CPU 25
When the reception data D2 is input from the reception circuit 17,
It is determined whether the ID code included in the received data D2 is different from the ID code of its own stored in the ROM 26 (step (hereinafter abbreviated as S) 11). In the present embodiment, data (detection data D
1. When transmitting the reception data D2), the CPU 25
Is given its own ID code stored in the ROM 26. Therefore, the CPU 25 compares the ID code included in the received data D2 with its own ID code to determine whether the newly received data (received data D2) or the data transmitted once (detection data D1 or received data D2). judge.

Then, the CPU 25 does not transfer the received data D2 when its own ID code is added, and transfers it when another ID code is added. When the reception data D2 transferred by the plurality of sensor devices 14a to 14f is received, the CPU2
5 is a plurality of ID codes and R included in the received data D2
The ID code stored in the OM 26 is compared to determine whether they are different.

By determining in S11 that the data is different, that is, the new data to which only the ID codes of the other sensor devices 14b to 14f are added (YES in S11),
The CPU 25 generates a pseudo random number. Then, the received data D2 once stored in the RAM 27 based on the result.
The transmission timing (time of transfer), that is, the data holding time Tr is determined (S12). Specifically, the CPU 25
Generates a pseudo-random number by a predetermined random number generation method such as the mixed congruential method. The CPU 25 adds or subtracts the generated pseudo-random number to the reference time (for example, 1 minute) stored in the ROM 26 in advance, so that the data holding time (1 minute ±
α) Tr is determined, and the timing for transmitting the reception data D2 is determined based on this data holding time Tr. Then, during the data holding time Tr, the received data D2 is R
It is temporarily stored in the AM 27 (S13).

After the data holding time Tr has elapsed, the CPU 25 reads the received data D2 from the RAM 27, adds its own ID code stored in the ROM 26, and outputs it to the transmission circuit 18 to execute the transfer (S14). Then, the transmission circuit 18 modulates the reception data D2 into a radio signal having a predetermined frequency and transmits (transfers) it to the outside.

At this time, since the reception data D2 is transmitted at random transmission timing based on the pseudo random number,
Data interference can be avoided. Specifically, when the data holding time Tr is set to a predetermined time in advance,
Data interference may occur. As an example, the data holding time Tr is set to, for example, 1 minute (same as the predetermined time I), and the order of transmission of the detection data D1 is different from that of the present embodiment, and the fourth sensor device is next to the first sensor device 14a. Assume that it is 14d. In this case, the sixth
The reception data D2 (wireless signal) from the sensor device 14f and the detection data D1 (wireless signal) from the fourth sensor device 14d are transmitted at the same timing. As a result, the sixth sensor device 14f and the fourth sensor device 14d
Interference will occur in the fifth sensor device 14e which is adjacent to and is capable of receiving the respective data D1 and D2 (radio signals). Unlike this case, if the transmission timing of the reception data D2 is randomly set by the pseudo random number, the transmission timings of the respective data D1 and D2 from the sixth sensor device 14f and the fourth sensor device 14d described above will be different. Therefore, data interference does not occur in the fifth sensor device 14e.

Now, when the wireless signal from the sixth sensor device 14f is transmitted, the fifth sensor device 14e capable of transmitting / receiving the same sensor device 14f transmits the wireless signal to the antenna 22.
To receive. Then, in the fifth sensor device 14e, the reception data D2 included in the wireless signal is input to the microcomputer 19 via the reception circuit 17. CPU of microcomputer 19
Reference numeral 25 denotes S11 to S11 of the flowchart shown in FIG. 4 according to the transfer control program as in the case of the sixth sensor device 14f.
The reception data D2 is output to the transmission circuit 18 by performing the processing and determination of S14. The processing flow of the CPU 25 in the fifth sensor device 14e is as follows.
Since it is the same as the processing flow of the CPU 25 in 4f, duplicate description thereof will be omitted. Then, in the fifth sensor device 14e, the reception data D2 is modulated into a radio signal by the transmission circuit 18 and transmitted (transferred) to the outside.

Next, the receiving antenna 31 of the monitor device 15
Receives a wireless signal from the fifth sensor device 14e. Then, the reception circuit 32 of the monitor device 15 demodulates the radio signal input via the reception antenna 31 and inputs it to the microcomputer 33. The microcomputer 33 determines whether the input air pressure data and temperature data are within the range of the reference data. If the air pressure data and the temperature data are within the range of the reference data, the first sensor device 14a
It is determined that the first tire 13a corresponding to is normal.
On the other hand, if the input air pressure data and temperature data of the first sensor device 14a are outside the range of the reference data, an operation signal is output to the display 34 to notify the abnormal state of the first tire 13a.

In this way, the detection data D1 in the first sensor device 14a is the sixth sensor device 14f and the fifth sensor device 14f.
It is transferred by the sensor device 14e and received by the monitor device 15. Therefore, even if the transmission intensity of the wireless signal from the first sensor device 14a is weak and the receiving antenna 31 of the monitor device 15 is not provided at a position where it can be received by the first sensor device 14a, the monitor The device 15 can preferably receive the detection data D1 of the first sensor device 14a.

The second, third and sixth sensor devices 14b, 1 other than the fifth sensor device 14e and the fourth sensor device 14d, which can directly transmit the detection data D1 to the monitor device 15, are provided.
Also for 4c and 14f, the detection data D1 is transferred and received by the monitor device 15 similarly to the first sensor device 14a. Briefly, the detection data D1 of the sixth sensor device 14f is transferred to, for example, the fifth sensor device 14e and received by the monitor device 15. Further, the detection data D1 of the second sensor device 14b is, for example, the third sensor device 14
c and the fourth sensor device 14d and transferred to the monitor device 1
5 is received. Further, the detection data D1 of the third sensor device 14c is transferred to, for example, the fourth sensor device 14d and received by the monitor device 15.

Next, data (detection data D1 or reception data D1) once transmitted from each of the sensor devices 14a to 14f.
2) is returned via the other sensor devices 14a to 14f.

For example, the first sensor device 14a and the sixth sensor device 14f can be transmitted and received. For this reason,
When the first sensor device 14a receives the reception data D2 from the sixth sensor device 14f, the first sensor device 14a may receive the transmitted detection data D1 as the reception data D2. Similarly, the fifth sensor device 14e and the sixth sensor device 14f can be transmitted and received. Therefore, when the sixth sensor device 14f receives the reception data D2 from the fifth sensor device 14e, the sixth sensor device 1
There is a case where the reception data D2 transferred by 4f is received.

In this case, the CPU 25 of the first sensor device 14a or the sixth sensor device 14f causes the ID included in the received data D2 in S11 of the flowchart shown in FIG.
It is determined that the code matches the own ID code stored in the ROM 26 (NO in S11). As a result, the CPU
25 determines that the once transmitted detection data D1 has returned and discards the same. In this way, the same data will not be transmitted (transferred) again from each of the sensor devices 14a to 14f, and the adjacent sensor devices 14a to 1 will not be transmitted.
The same data is not repeatedly transmitted and received between 4f.

Therefore, according to the above embodiment, the following effects can be obtained. (1) In the above embodiment, each of the sensor devices 14a to 14f.
The receiver circuit 17 and the transmitter circuit 18 are provided in the above, and the received data D2 received from the other sensor devices 14a to 14f via the receiver circuit 17 is wirelessly transferred via the transmitter circuit 18. For this reason, even when the detection data D1 of an arbitrary sensor device (for example, the first sensor device 14a) cannot be received by the monitor device 15, it is transferred via another sensor device (for example, the sixth and fifth sensor devices 14e, 14f). By doing so, the monitor device 15 can be made to receive. As a result, it is not necessary to provide a large number of receiving antennas 31 on the monitor device 15 so as to correspond to the sensor devices 14a to 14f. Even if the transmission intensity is weak, the number of receiving antennas 31 is small and the monitor device 15 is suitable.
Can receive data indicating the tire condition of each tire 13a to 13f. Further, by reducing the number of receiving antennas 31, it is possible to reduce the cost of the monitor device 15.

(2) In the above embodiment, the received data D2 received via the receiving circuit 17 is temporarily stored in the RAM 27 and then transferred. Therefore, CPU2
5 makes it possible to change the transmission timing of the reception data D2 and transfer the reception data D2, thereby preventing interference of data (radio signal).

(3) In the above embodiment, the air pressure sensor 2
The ID code is added to the air pressure data and the temperature data input from 0 and the temperature sensor 21, and the data is transmitted to the outside. Further, the received data D2 is also given an ID code and transmitted to the outside. Therefore, the first to sixth sensor devices 14a to 14f (CPU
25) can easily determine whether or not the data is the data transmitted by itself (detection data D1, reception data D2) by comparing the ID codes.

(4) In the above embodiment, the CPU 25
ID code and ROM included in the received data D2 received
The ID code is compared with its own ID code stored in No. 26, and if they match, the transfer is not performed. When the reception data D2 having the ID code that matches the ID code of itself is received, the transmitted data (detection data D1, reception data D
Since 2) has returned, the same data will not be repeatedly transmitted and received.

(5) In the above embodiment, the microcomputer 19 generates a pseudo random number and determines the timing of transferring the received data D2 based on the pseudo random number. Therefore, the transmission timing can be easily and randomly set by the pseudo-random number, and the data interference can be preferably prevented.

The above embodiment may be modified as follows. In the above-described embodiment, the tire pressure monitoring device 11 is provided in a large vehicle having six tires 13a to 13f, but the tire pressure monitoring device 11 is provided in a normal vehicle (passenger vehicle) having four tires. Good. In addition, the tires 13a to 13
The number of f may be more than six.

In the above embodiment, the CPU 25 generates a pseudo random number and changes the data holding time Tr based on the pseudo random number. However, for example, a plurality of data holding times Tr are stored in the ROM 26 in advance, and the CPU 25 It is also possible to adopt a mode in which the pseudo-random number is not used, such as selecting any of the above.

In the above embodiment, the CPU 25 compares the ID code included in the received data D2 with its own ID code so as not to transfer the received data D2, but compares the ID code. Instead, the received data D2 may be transferred.

Also, even if the ID codes match, the transfer may be repeated until a predetermined number of times of continuous reception. In this case, for example, a counter is provided to count the number of times that the ID code of the received data D2 received matches the ID code of itself. Then, based on this counter, if they match a predetermined number of times or more, the data is discarded. Even in this case, the same data is not repeatedly transmitted and received.

In the above embodiment, the CPU 25 stores the received data D2 in the RAM 27 during the data holding time Tr and then transfers the received data D2. However, the CPU 25 may transfer the received data D2 immediately after receiving it. .

In the above embodiment, S11 and S1 of the flowchart based on the transfer control program shown in FIG.
The order of 2 may be exchanged. Even in this case, appropriate processing can be realized for the reception data D2.

In the above embodiment, the detection data D1
Is not limited to the above-mentioned route that is transferred as the reception data D2, and the sensor devices 14a to 14f capable of transmitting and receiving.
Any route may be followed as long as it is transferred between the two and received by the monitor device 15. For example, it can be considered that the detection data D1 of the first sensor device 14a is transferred to the second sensor device 14b, the third sensor device 14c, and the fourth sensor device 14d and is received by the monitor device 15.

Next, the technical ideas which can be understood from the above-described embodiment and each other example will be added below. (A) The tire pressure detection device according to any one of claims 1 to 5 and a tire condition included in the wireless signal, the tire pressure detection device having a receiving antenna capable of receiving a wireless signal transmitted from the device. A tire air pressure monitoring device having a tire air pressure monitoring device having a determination means for making a tire abnormality determination corresponding to the tire air pressure detecting device based on data indicating the tire air pressure detecting device, wherein the tire air pressure detecting device is a wireless signal. A plurality of tire air pressure monitoring devices are provided at transferable positions, and the tire air pressure monitoring device is provided at a position at which a wireless signal from at least one of the plurality of tire air pressure detecting devices can be received. Tire pressure monitoring device.

[0054]

As described in detail above, according to the present invention,
Even when the transmission strength of the wireless signal is weak, the monitor device having a small number of receiving antennas can preferably receive the data indicating the tire condition, and the number of receiving antennas can be reduced to reduce the cost of the monitoring device. .

[Brief description of drawings]

FIG. 1 is a schematic plan view of a vehicle provided with a tire pressure monitoring device.

FIG. 2 is a block diagram showing an electrical configuration of a sensor device.

FIG. 3 is a timing chart showing transmission timings of detection data and reception data transmitted from each sensor device.

FIG. 4 is a flowchart showing processing of a CPU based on a transfer control program.

[Explanation of symbols]

13a-13f ... 1st-6th tire, 14a-14f ...
1st-6th sensor apparatus (tire pressure detection apparatus), 17
... reception circuit (reception means), 18 ... transmission circuit (transmission means), 20 ... air pressure sensor (tire state detection means), 2
1 ... Temperature sensor (tire state detection means), 22 ... Antenna (reception means, transmission means), 25 ... CPU (transfer means,
Identification data giving means, random number generating means), 27 ... RAM
(Memory means).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromitsu Mizuno             260-chome, Toyota, Oguchi-cho, Niwa-gun, Aichi             Tokai Rika Electric Co., Ltd. F term (reference) 2F055 AA12 BB20 CC60 DD20 EE40                       FF34                 2F073 AA02 AA03 AA36 AB01 AB07                       BB02 BC02 CC03 CC08 CC12                       CC14 DD10 DE16 EE07 EF09                       FF02 GG01 GG07

Claims (5)

[Claims] 1. A tire pressure including a tire condition detecting means for detecting a tire condition including at least tire pressure, and a transmitting device for transmitting data indicating the tire condition (hereinafter referred to as first data) as a radio signal. In the detecting device, the receiving means capable of receiving the wireless signal transmitted from the other tire pressure detecting device, and the data indicating the tire condition of the other tire included in the received wireless signal (hereinafter, referred to as second data) are described above. A tire air pressure detection device comprising: a transfer unit that transfers a wireless signal via a transmission unit. 2. The storage device according to claim 1, further comprising a storage unit capable of storing the second data, wherein the transfer unit transfers the received second data after temporarily storing the received second data in the storage unit. Tire pressure detection device. 3. An identification data assigning unit that assigns its own identification data to the first data and the second data, wherein the transmitting unit transmits each data to which the identification data is attached as a radio signal. The tire air pressure detection device according to claim 1 or 2, wherein: 4. The transfer means determines whether or not identification data other than itself is added to the second data received by the reception means, and determines that the identification data of itself is added. Is not transferred. The tire pressure detecting device according to claim 3, wherein 5. The random number generating means for generating a random number is provided, and the transfer means determines the time when the second data stored in the storage means is transferred based on the random number. The tire pressure detection device according to any one of claims 4 to 4.