JP3815304B2 - Tire pressure monitoring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention receives a tire identification code, a detected air pressure, and a detected temperature sent from a transmitter individually provided for each tire by a receiver, and a mounted tire (traveling tire) and a non-mounted tire (spare tire). It belongs to the technical field of a tire pressure monitoring device for distinguishing and monitoring each tire pressure.
[0002]
[Prior art]
Conventionally, as a tire pressure alarm device, for example, the one described in Japanese Patent No. 3061047 is known.
[0003]
In this conventional publication, a tire identification code (ID: identification) sent from a transmitter that is individually attached to each tire is received by a receiver and registered within a predetermined time when it is registered. A technique for storing (registering) an ID from a higher one is described.
[0004]
[Problems to be solved by the invention]
However, in the conventional tire pressure alarm device, erroneous registration of IDs of other vehicles can be avoided in places where many vehicles are crowded, but it is also installed from non-mounted tires installed in the spare tire space of the own vehicle. If data is transmitted in the same manner as the tire, the reception frequency from the non-mounted tire becomes the same as the reception frequency from the mounted tire, and the ID of the non-mounted tire may be erroneously registered as the mounted tire. In that case, there is a possibility that the alarm of the air pressure of the mounted tire which is not registered in ID cannot be performed.
[0005]
Further, if a tire ID must be re-registered by using a dedicated device at a dealer or the like after replacing the tire, it will be necessary to re-register the ID every time the tire is replaced, which is not practical.
[0006]
The present invention has been made paying attention to the above-mentioned problems. The purpose of the present invention is to distinguish between mounted tires and non-mounted tires, and automatically identify codes without using dedicated equipment even when tires are replaced. It is an object of the present invention to provide a tire pressure monitoring device that can perform re-registration.
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, in the invention according to claim 1,
  In vehicles with multiple tires,
  Air pressure detecting means for detecting the air pressure of each tire;
  Temperature detecting means for detecting the temperature of each tire;
  Transmitting means for transmitting each tire individual identification code, detected air pressure and detected temperature by radio signal;
  Receiving means attached to a vehicle and receiving a radio signal from the transmitting means;
  Storage means for storing an identification code of a mounting tire mounted on a vehicle axle as a running tire;
  Tire group dividing means for dividing the first tire group having the same tire temperature change tendency during traveling into a second tire group having a different tire temperature change tendency during traveling;
  A tire identification code registration means for registering, in the storage means, the tire identification code of a group having a number of tire identification codes corresponding to the number of running tires;
  With,
  The tire grouping means includes
  Tire average temperature calculating means for calculating the average temperature of all tires including spare tires added to all installed tires;
  Each tire temperature and tire average temperature deviation is calculated, and if this deviation exceeds zero, the corresponding tire identification code is put in the first group, and if the deviation is less than zero, the corresponding tire Identification code grouping means for putting the identification codes in the second group;
  HaveIt is characterized by that.
[0009]
  Claim 2In the invention according toClaim 1In the tire pressure monitoring device described in
  The mounted tire identification code registration means is
  When there are identification codes for the number of running tires in either the first group or the second group, a group in which the identification codes exist for the number of running tires is re-registered in the storage means as the identification codes of the mounted tires. And when the identification code for the number of running tires does not exist in either the first group or the second group, the identification codes of the mounted tires are not replaced and remain registered. .
[0010]
  Claim 3In the invention according toClaim 1In the tire pressure monitoring device described in
  The mounted tire identification code registration means is
  If there are common identification codes for the number of traveling tires in the identification code of the first group divided as the installation tires and the identification codes already registered as installation tires, they are registered as installation tires. If there is an identification code that is not common between the identification code of the first group and the registered identification code without replacing the identification code, the identification codes that are not common are exchanged and registered in the storage means. It is characterized by doing.
[0011]
Operation and effect of the invention
In the invention according to claim 1, in the transmission means, the identification code for each tire, the air pressure detected by the air pressure detection means and the temperature detected by the temperature detection means are transmitted by radio signals, and are sent to the vehicle. In the attached receiving means, the radio signal from the transmitting means is received. Then, the tire group dividing means is divided into a first tire group having the same change tendency of the tire temperature during traveling and a second tire group having a different change tendency of the tire temperature during traveling. In the mounted tire identification code registration means, the identification codes of the tires in the group having the number of tire identification codes corresponding to the number of running tires are registered in the storage means as the identification codes of the mounted tires.
[0012]
In other words, when a tire is mounted (running tire), the internal temperature of each tire tends to increase due to frictional heat with the road surface due to similar temperature characteristics, while a non-wearing tire (spare tire) Since it is still mounted in the tire space of the vehicle, the temperature inside the tire does not rise, so there is almost no temperature change.
[0013]
Therefore, by monitoring the change in tire temperature, it is possible to distinguish between fitted tires and non-weared tires, and by registering the identification codes of the worn tires that have been distinguished, without using dedicated equipment even when replacing the tires. It is possible to automatically register the identification code again.
[0014]
  In addition, claim 1In the invention according to the above, when the tire grouping is performed, the tire average temperature calculating means calculates, for example, in the case of a four-wheeled vehicle, the average tire temperature of five wheels including a four-wheeled tire and a spare tire. In the identification code grouping means, the deviation between each tire temperature and the tire average temperature is calculated, and when this deviation exceeds zero, the identification code of the corresponding tire is put in the first group, and the deviation is If it is less than or equal to zero, the corresponding tire identification code is placed in the second group.
[0015]
Therefore, the mounted tire and the non-mounted tire can be reliably distinguished by a simple method of determining the size of the tire temperature based on the average tire temperature of the five wheels.
[0016]
  Claim 2In the invention according to the present invention, when registering the identification code of the mounted tire, for example, in the case of a four-wheeled vehicle, if there are four identification codes in either the first group or the second group, the identification code Is re-registered in the storage means as a tire identification code, and if there are no four identification codes in either the first group or the second group, the tire identification is performed. The registered code is not changed without changing the code.
[0017]
Therefore, when a spare tire is mounted by replacing the tire, when it is recognized that there are four tires having the same tendency to change in tire temperature, the identification code of the replaced spare tire is re-registered as an identification code of the mounted tire by replacing all of them. After the tire replacement, the identification code can be re-registered at an early stage.
[0018]
  Claim 3In the invention according to the present invention, when registering the identification code of the mounted tire, for example, in the case of a four-wheeled vehicle, the identification code of the first group divided as the mounted tire and the identification code already registered as the mounted tire When there are four common identification codes, the identification codes registered as wearing tires are not exchanged, and are common to the first group identification codes and the registered identification codes. If there is an unidentified identification code, only the uncommon identification code is replaced and re-registered.
[0019]
Therefore, when a spare tire is mounted by exchanging tires, when the existence of an identification code that does not match the identification code of the first group is recognized, partial replacement of only the identification code of the replaced spare tire is performed. The registration code can be re-registered at an early stage after tire replacement. In addition, because it is re-registration by partial replacement based on the identification code that has already been registered as a mounted tire, even if the wrong identification code is included for some reason, only the wrong identification code is replaced Thus, it is possible to register the identification code of the mounting tire with high reliability so that the registration of the common identification code is always ensured as the mounting tire.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an embodiment for realizing a tire pressure monitoring device according to the present invention will be described.Claims 1 and 2A first embodiment corresponding toClaim 3And a second embodiment corresponding to the above.
[0021]
(First embodiment)
First, the configuration will be described.
FIG. 1 is an overall view showing a vehicle to which the tire pressure monitoring device of the first embodiment is applied. In FIG. 1, 1 is a right front wheel tire, 2 is a left front wheel tire, 3 is a right rear wheel tire, and 4 is a left side. Rear tire, 5 spare tire, 6 right front wheel speed sensor, 7 left front wheel speed sensor, 8 right rear wheel speed sensor, 9 left rear wheel speed sensor, 10 tire pressure sensor, 11 ABS controller, 12 is a tire air pressure alarm controller, and 13 is a low air pressure warning lamp.
[0022]
The right front wheel speed sensor 6, the left front wheel speed sensor 7, the right rear wheel speed sensor 8, and the left rear wheel speed sensor 9 detect the wheel speeds of the front and rear wheels 1, 2, 3, and 4, and the wheel speed sensor signals are detected. Input to the ABS controller 11.
[0023]
The tire pressure sensor 10 is attached to the road wheels of the front and rear tires 1, 2, 3, 4 and the spare tire 5, respectively, and detects the tire pressure and the tire temperature of each tire, and the ID (identification) of each tire. ) And the detected tire pressure and tire temperature are transmitted as radio signals to a tire pressure alarm controller 12 having a receiving function.
[0024]
The ABS controller 11 receives wheel speed sensor signals from the wheel speed sensors 6, 7, 8, 9 and outputs vehicle speed information (vehicle speed, wheel speed, etc.) to the tire air pressure alarm controller 13.
[0025]
When the tire pressure warning controller 12 determines that the mounted tire (front and rear wheel tires 1, 2, 3, 4) and the non-mounted tire (spare tire 5) are separated, and the mounted tire pressure is reduced, A lamp lighting command is output to the air pressure reduction warning lamp 13.
[0026]
FIG. 2 is a detailed view showing the tire pressure sensor 10 and the tire pressure alarm controller 12 of the tire pressure monitoring device of the first embodiment.
[0027]
The tire air pressure sensor 10 includes a pressure sensor 10a (air pressure detecting means) that detects tire air pressure (internal pressure), a centrifugal force switch 10b that is open in a region where the acting centrifugal force is small and is closed in a region where the centrifugal force is large, A temperature sensor 10c (temperature detection means) that detects the temperature inside the tire, an ASIC 10d that is an application specific integrated circuit, a transmitter 10e, and a transmission antenna 10f (transmission means) are configured. Then, with the opening / closing of the centrifugal switch 10b installed to ensure the battery life as a trigger, a long transmission interval (1 hour) in a region where the vehicle speed including stop is low, and a short transmission interval in a region where the vehicle speed is higher than that. (1 minute) The transmission cycle is changed into two stages, and the modulated pressure value information from the pressure sensor 10a, the modulated temperature information from the temperature sensor 10c, and the ID information for each tire are used using electromagnetic waves. Send.
[0028]
The tire pressure warning controller 12 includes a 5V power supply circuit 12a, a receiving antenna 12b and a receiving circuit 12c (receiving means) for receiving transmission data from the transmitting antenna 10f of the tire pressure sensor 10, and vehicle speed information from the ABS controller 11. The vehicle speed information input circuit 12d for inputting the received data, the reception data from the receiving circuit 12c, the vehicle speed information from the vehicle speed information input circuit 12d, and the microcomputer 12e for performing arithmetic processing according to a predetermined control law, and ID registration EEPROM 12f (storage means) that is a read-only memory that can electrically erase stored information, and a warning lamp that determines a pressure value in the received data and outputs a tire air pressure warning command to a low air pressure warning lamp 13 when the pressure drops An output circuit 12g is included.
[0029]
Next, the operation will be described.
[0030]
[Installation tire ID registration calculation process]
FIG. 3 and FIG. 4 are flowcharts showing the flow of the ID registration calculation process of the attached tire executed by the tire air pressure alarm controller 12 of the first embodiment, and each step will be described below.
[0031]
In step S1, the in-tyre temperature for five wheels, each of the tires 1, 2, 3, 4 and the spare tire 5 that are the mounted tires, is set to T.₁, T₂, T₃, T₄, T₅In step S2, it is determined whether or not five wheels of radio waves have been received. If it is determined in step S2 that the number of wheels is equal to or less than four, the process proceeds to step S3, and the ID of the mounted tire is not replaced.
[0032]
If it is determined in step S2 that radio waves for five wheels have been received, the process proceeds to step S4, and in step S4, the tire average temperature T_HIs calculated by the following equation (corresponding to the tire average temperature calculating means of claim 2).
T_H= (T₁+ T₂+ T₃+ T₄+ T₅) / 5
In the next step S5, the tire internal temperature T₁And tire average temperature T_HWhether or not the deviation from the tire temperature exceeds zero is determined.₁And tire average temperature T_HIs greater than zero, the process proceeds to step S6, where the tire internal temperature T₁The tire ID is put in group 1 and the process proceeds to step S8. On the other hand, the tire internal temperature T₁And tire average temperature T_HIs less than zero, the process proceeds to step S7, where the tire internal temperature T₁The tire ID is entered in group 2 and the process proceeds to step S8.
[0033]
Similarly, in step S8, the tire internal temperature T₂And tire average temperature T_HWhether or not the deviation from the tire temperature exceeds zero is determined.₂And tire average temperature T_HIs greater than zero, the process proceeds to step S9, where the tire internal temperature T₂The tire ID is entered in group 1 and the process proceeds to step S11. On the other hand, the tire internal temperature T₂And tire average temperature T_HIs less than zero, the process proceeds to step S10. In step S10, the tire internal temperature T₂The tire ID is entered in group 2 and the process proceeds to step S11.
[0034]
Similarly, in step S11, the tire internal temperature T₃And tire average temperature T_HWhether or not the deviation from the tire temperature exceeds zero is determined.₃And tire average temperature T_HIs greater than zero, the process proceeds to step S12. In step S12, the tire internal temperature T₃The tire ID is put in group 1 and the process proceeds to step S14. On the other hand, the tire internal temperature T₃And tire average temperature T_HIs less than zero, the process proceeds to step S13, where the tire internal temperature T₃The tire ID is entered in group 2 and the process proceeds to step S14.
[0035]
Similarly, in step S14, the tire internal temperature T₄And tire average temperature T_HWhether or not the deviation from the tire temperature exceeds zero is determined.₄And tire average temperature T_HIs greater than zero, the process proceeds to step S15. In step S15, the tire internal temperature T₄The tire ID is entered in group 1 and the process proceeds to step S17. On the other hand, the tire internal temperature T₄And tire average temperature T_HIs less than zero, the process proceeds to step S16. In step S16, the tire internal temperature T₄The tire ID is entered in group 2 and the process proceeds to step S17.
[0036]
Similarly, in step S17, the tire internal temperature T₅And tire average temperature T_HWhether or not the deviation from the tire temperature exceeds zero is determined.₅And tire average temperature T_HIs greater than zero, the process proceeds to step S18. In step S18, the tire internal temperature T₅The tire ID is put in group 1 and the process proceeds to step S20. On the other hand, the tire internal temperature T₅And tire average temperature T_HIf the deviation from is zero or less, the process proceeds to step S19. In step S19, the tire internal temperature T₅The tire ID is entered in group 2 and the process proceeds to step S20.
[0037]
Steps S5 to S19 correspond to the identification code grouping means of claim 2.
[0038]
In the next step S20, it is determined whether or not four IDs exist in either group 1 or group 2. If there are four IDs in either group 1 or group 2, The process proceeds to S21. In step S21, a group having four IDs is recognized as a group of attached tires, and this is stored and registered. On the other hand, if four IDs do not exist in either group 1 or group 2, the process proceeds to step S22, and the IDs registered as the ID group of the attached tire are not replaced.
[0039]
Steps S20 to S22 correspond to the fitted tire identification code registration means of claim 3.
[0040]
[Installation tire ID registration]
For example, as shown in FIG. 5, before tire replacement, the right front wheel tire was ID1, the left front wheel tire was ID2, the right rear wheel tire was ID3, the left rear wheel tire was ID4, and the spare tire was ID5. After the tire replacement, the ID registration function of the mounted tire will be described in the case where the right rear wheel tire is ID5 and the spare tire is ID3 and the vehicle travels after the tire replacement.
[0041]
In this case, in the flowcharts of FIGS. 3 and 4, the process proceeds to step S1, step S2, step S4, step S5, step S6, and, as shown in FIG.₁Is the average tire temperature T_HIn step S6, the tire internal temperature T is exceeded.₁ID1 of the tire (attached to the right front wheel) is put in group 1.
[0042]
And it progresses from step S6 to step S8-> step S9, and as shown in FIG.₂Is the average tire temperature T_HIn step S9, the tire internal temperature T is exceeded.₂ID2 of the tire (attached to the left front wheel) is put in group 1.
[0043]
Then, the process proceeds from step S9 to step S11 to step S13, and as shown in FIG.₃Is the average tire temperature T_HIn step S13, the tire internal temperature T₃ID3 of the tire (installed in the spare tire space) is put in group 2.
[0044]
And it progresses from step S13 to step S14-> step S15, and as shown in FIG.₄Is the average tire temperature T_HIn step S15, the tire internal temperature T is exceeded.₄ID4 of the tire (attached to the left rear wheel) is put in group 1.
[0045]
And it progresses from step S15 to step S17-> step S18, and as shown in FIG.₅Is the average tire temperature T_HIn step S18, the tire internal temperature T is exceeded.₅ID5 of the tire (with a spare tire attached to the right rear wheel) is put into group 1.
[0046]
In the next step S20, ID1, ID2, ID4, and ID5 exist in group 1, ID3 exists in group 2, and four IDs exist in group 1, and the process proceeds to step S21. ID registration (ID1, ID2, ID4, ID5) is performed with group 1 as a group of tires.
[0047]
That is, as shown in FIG. 6, the tires mounted (running tires) tend to rise due to frictional heat with the road surface when the vehicle starts running, while the internal temperature of each tire tends to increase due to similar temperature characteristics. Since the tire (spare tire) is still mounted in the tire space of the vehicle, the temperature inside the tire does not rise, so there is almost no temperature change.
[0048]
Therefore, the change tendency of the tire temperature is expressed as the average tire temperature T of the five wheels._HTire internal temperature T₁, T₂, T₃, T₄, T₅Can be distinguished from non-mounted tires (ID3) by registering the IDs of the mounted tires as in the above example. Even when the right rear wheel tire is replaced with a spare tire, the ID can be automatically registered again without using a dedicated device.
[0049]
Next, the effect will be described.
[0050]
(1) A tire group (group 1) having the same trend of change in tire temperature during traveling is divided into a tire group (group 2) and a tire group (group 2) having a different tendency of tire temperature during traveling. Since the ID of the group with the ID of the number of tires corresponding to the number of running tires (four) is registered as the ID of the mounted tire, it is possible to distinguish between the mounted tire and the non-mounted tire, even when the tire is replaced The ID can be automatically re-registered without using a device.
[0051]
(2) When the tire grouping is performed, in step S4, the average temperature T in the five-wheel tire in which the spare tire 5 is added to the four-wheel mounted tires 1, 2, 3, 4_HIn step S5, S8, S11, S14, and S17, the temperature T in each tire is calculated.₁, T₂, T₃, T₄, T₅And tire average temperature T_HWhen the deviation exceeds zero, the corresponding tire ID is put into group 1, and when the deviation is less than zero, the corresponding tire ID is put into group 2. Average tire temperature T for five wheels_HTire internal temperature T₁, T₂, T₃, T₄, T₅With a simple method of determining the size of the tire, it is possible to reliably distinguish between a mounted tire and a non-mounted tire.
[0052]
(3) When registering the IDs of the mounted tires, if there are four IDs in either group 1 or group 2 in step S20, the process proceeds to step S21, and group 1 having four IDs is assigned to the mounted tire. If it is re-registered as an ID identification code, and if there are no four IDs in either group 1 or group 2, the process proceeds to step S22, and the IDs of the attached tires are not replaced and remain registered. Therefore, when the spare tire 5 is mounted by replacing the tire, the ID (ID5) of the replaced spare tire 5 is all set as the ID of the mounted tire when it is recognized that there are four tires having the same tendency of temperature change in the tire. It is re-registered by replacement, and ID can be re-registered at an early stage after tire replacement.
[0053]
(Second embodiment)
In the first embodiment, when registering the ID of the mounted tire, an example of re-registering as the ID of the mounted tire is re-registered. However, in the second embodiment, the ID of the mounted tire is re-registered by partially replacing the ID. This is an example. Since the configuration of the second embodiment is the same as that of the first embodiment, illustration and description thereof are omitted.
[0054]
Next, the operation will be described.
[0055]
[Installation tire ID registration calculation process]
FIG. 7 and FIG. 8 are flowcharts showing the flow of the ID registration calculation process of the attached tire executed by the tire air pressure alarm controller 12 of the second embodiment, and each step will be described below. Steps S101 to S119 are the same as steps S1 to S19 in the flowcharts shown in FIGS.
[0056]
In the next step S120, it is determined whether or not there are four common IDs in the group 1 IDs divided as the mounted tires and the IDs already registered as the mounted tires. If it exists, the process proceeds to step S122, and the IDs registered as mounted tires are not exchanged. If there are no four common IDs, the process proceeds to step S121, and only non-common IDs are exchanged. Will be re-registered.
[0057]
In addition, step S120-step S122 are equivalent to the mounting tire identification code registration means of Claim 4.
[0058]
Next, the effect will be described.
[0059]
In the tire air pressure monitoring device of the second embodiment, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
[0060]
(4) When registering the IDs of the mounted tires, if there are four common IDs in the group 1 ID divided as the mounted tires and the IDs already registered as mounted tires, they are registered as mounted tires. If the four IDs that are common to the group 1 ID and the registered ID do not exist, only the non-common IDs are exchanged. When the tire 5 is mounted, when it is recognized that there is a group ID that does not match the registered ID, it is re-registered by partial replacement of only the ID of the replaced spare tire 5, and after the tire replacement ID can be re-registered at an early stage.
[0061]
In addition, since it is re-registration by partial replacement based on the ID already registered as a mounted tire, even if an incorrect ID is included for some reason, only the incorrect ID is replaced, which is common. It is possible to register the ID of the mounted tire with high reliability so that registration is always ensured as a mounted tire.
[0062]
(Other examples)
The tire pressure monitoring device of the present invention has been described based on the first embodiment and the second embodiment. However, the specific configuration is not limited to these embodiments, and each of the claims Design changes and additions are allowed without departing from the scope of the present invention described in the claims.
[0063]
For example, in the first and second embodiments, the tire group is divided into a tire group having the same tendency of change in tire temperature during traveling and a group of tires having a different tendency of change in tire temperature during traveling. As a means, the average temperature T in the tires of the five wheels_HTire internal temperature T₁, T₂, T₃, T₄, T₅However, the difference in the temperature characteristics of the tires, such as dividing the tire group according to whether or not it has a temperature rise gradient above a predetermined level, is monitored. Other methods may be used as long as the grouping is focused.
[0064]
Also, the ID registration process for the attached tire may be performed in a region where the vehicle speed is equal to or higher than the set vehicle speed, or when the travel time or travel distance is greater than a predetermined value, or the travel conditions may be clarified.
[Brief description of the drawings]
FIG. 1 is an overall view showing a vehicle to which a tire pressure monitoring device according to a first embodiment is applied.
FIG. 2 is a detailed view showing a tire pressure sensor and a tire pressure alarm controller of the tire pressure monitoring device of the first embodiment.
FIG. 3 is a flowchart 1 showing a flow of an ID registration calculation process of a mounted tire executed by a tire pressure alarm controller of the tire pressure monitoring device of the first embodiment.
FIG. 4 is a flowchart 2 showing the flow of an ID registration calculation process for a mounted tire executed by a tire pressure alarm controller of the tire pressure monitoring device of the first embodiment.
FIG. 5 is a diagram showing the ID of each tire before and after tire replacement.
FIG. 6 is a temperature characteristic diagram in the tire of each tire including a spare tire.
FIG. 7 is a flowchart 1 showing a flow of an ID registration calculation process for a mounted tire executed by a tire pressure alarm controller of the tire pressure monitor device of the second embodiment.
FIG. 8 is a flowchart 2 showing a flow of ID registration calculation processing of a mounted tire executed by a tire pressure alarm controller of the tire pressure monitoring device of the second embodiment.
[Explanation of symbols]
1 Right front wheel tire
2 Left front wheel tire
3 Right rear wheel tire
4 Left rear wheel tire
5 Spare tires
6 Right front wheel speed sensor
7 Left front wheel speed sensor
8 Right rear wheel speed sensor
9 Left rear wheel speed sensor
10 Tire pressure sensor
11 ABS controller
12 Tire pressure alarm controller
13 Low air pressure warning lamp

Claims (3)

In vehicles with multiple tires,
Air pressure detecting means for detecting the air pressure of each tire;
Temperature detecting means for detecting the temperature of each tire;
Transmitting means for transmitting the identification code for each tire, the air pressure detected by the air pressure detecting means, and the temperature detected by the temperature detecting means by radio signals;
Receiving means attached to a vehicle and receiving a radio signal from the transmitting means;
Storage means for storing an identification code of a mounting tire mounted on a vehicle axle as a running tire;
Tire group dividing means for dividing the first tire group having the same tire temperature change tendency during traveling into a second tire group having a different tire temperature change tendency during traveling;
A tire identification code registration means for registering, in the storage means, the tire identification code of a group having a number of tire identification codes corresponding to the number of running tires;
Equipped with a,
The tire grouping means includes
Tire average temperature calculating means for calculating the average temperature of all tires including spare tires added to all installed tires;
Each tire temperature and tire average temperature deviation is calculated, and if this deviation exceeds zero, the corresponding tire identification code is put in the first group, and if the deviation is less than zero, the corresponding tire Identification code grouping means for putting the identification codes in the second group;
Tire air pressure monitoring system characterized by having a. In the tire pressure monitoring device according to claim 1,
The mounted tire identification code registration means is
When there are identification codes for the number of running tires in either the first group or the second group, a group in which the identification codes exist for the number of running tires is re-registered in the storage means as the identification codes of the mounted tires. And when the identification code for the number of running tires does not exist in either the first group or the second group, the identification codes of the mounted tires are not replaced and remain registered. Tire pressure monitoring device. In the tire pressure monitoring device according to claim 1,
The mounted tire identification code registration means is
If there are common identification codes for the number of traveling tires in the identification code of the first group divided as the installation tires and the identification codes already registered as installation tires, they are registered as installation tires. If there is an identification code that is not common between the identification code of the first group and the registered identification code without replacing the identification code, the identification codes that are not common are exchanged and registered in the storage means. A tire pressure monitoring device characterized by:

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