JP5521817B2 - Transmitter for transmitting tire information and tire information monitoring system - Google Patents

Description

  The present invention relates to a transmission device that is provided in a tire cavity region and transmits tire information related to a tire state, and a tire information monitoring system that determines whether or not there is a tire abnormality.

  Conventionally, checking and managing the air pressure of tires mounted on a vehicle has been important in terms of improving tire durability, wear resistance, fuel economy, riding comfort, and steering performance. It is desired. For this reason, various systems for monitoring the tire air pressure have been proposed. In general, this system detects information on the pressure of a tire mounted on a wheel, and provides a transmitting device for transmitting the information in the tire cavity region of each wheel, and sends information on the pressure of each tire from the transmitting device. Obtain and monitor tire pressure.

  On the other hand, a puncture repair agent that is injected into a tire cavity region sandwiched between a tire and a rim when the tire is punctured is often used. Since the puncture repair agent is liquid, when the puncture repair agent is injected into the tire cavity region, the puncture repair agent is applied not only to the tire inner surface facing the tire cavity region but also to the transmitting device provided in the tire cavity region. Adheres, and in some cases, solidifies and closes an opening provided in the transmission device, affecting the measurement of air pressure.

In order to solve this problem, there has been proposed a wheel state detection device capable of preventing a foreign substance from entering from a detection communication portion and maintaining a normal detection state (Patent Document 1).
Specifically, a TPMS (Tire Pressure Monitoring System) valve of the wheel state detection device is provided with a communication portion opening / closing mechanism that opens and closes a communication hole provided in the case. In the case of puncture repair, the puncture repair agent is restricted from entering the detection space through the communication hole. This communication portion opening / closing mechanism is constituted by a mechanical mechanism including a lid and a torsion coil spring, and the communication hole is automatically opened and closed by a centrifugal force acting on the wheel.

Further, a tire pressure monitoring system and a tire pressure sensor unit have been proposed that can inform the occupant that the tire pressure may subsequently drop when a puncture repair agent is used during puncture repair (Patent Literature). 2).
Specifically, the tire pressure monitoring system is provided in each tire of a vehicle, and includes a sensor unit having a pneumatic sensor and a transmitter, a receiver that receives radio waves from the sensor unit, and the pneumatic pressure of each tire is below a threshold value. And a control ECU that issues an alarm. In this system, there is provided a puncture judging means for judging a puncture of each tire, and a puncture repair agent use judging means for judging whether or not the puncture has been repaired using the puncture repair agent after the puncture is judged. When it is determined that the punctured tire has been repaired using the puncture repair agent, the control ECU continues the alarm even if the tire air pressure value from the air pressure sensor is a normal value.

JP 2008-62730 A JP 2007-196834 A

Since the communication portion opening / closing mechanism of the device described in Patent Document 1 is configured by a mechanical mechanism including a lid and a torsion coil spring, there is a problem that the device itself becomes complicated and expensive.
In the system and unit described in Patent Document 2, it is not known whether or not the tire pressure information measured after repairing the tire using the puncture repair agent is correct. For this reason, it is not possible to determine the presence or absence of tire abnormality after puncture repair.

  Therefore, the present invention provides a transmission device that can properly detect and transmit tire information such as tire air pressure information even if the tire puncture is repaired using a puncture repair agent by a new method different from the above-described conventional technology. It is another object of the present invention to provide a tire information monitoring system that determines the presence or absence of tire abnormality.

One aspect of the present invention is a transmission device that is provided in a tire cavity region and transmits tire information related to a tire state.
The transmission device includes a sensor that detects, as tire information, a gas state filled in a tire cavity region surrounded by a tire and a rim.
A transmitter for wirelessly transmitting the detected tire information;
A wall covering the sensor and the transmitter; an internal space defined by the wall from the tire cavity region; and a vent hole penetrating the wall to communicate the internal space and the tire cavity region. A housing, and
A brush-like region in which a plurality of flexible filaments are erected from the surface of the housing is formed around the vent hole.

At that time, the filament is made of a thermoplastic resin selected from polyethylene naphthalate, polybutylene terephthalate, polyethylene terephthalate, nylon 6 and nylon 66, and the filament preferably has a diameter of 1 mm or less.
The density of the filaments in the brush-like region is preferably 30 or more per 100 mm ² .
The brush-like region is preferably formed in an annular shape around the vent hole, and the width of the annular brush-like region is preferably 10 mm or more.
The brush-like region is preferably formed in an annular shape around the vent hole, and an inner edge of the annular brush-like region is preferably 2 mm or more and 10 mm or less away from the vent hole.

In addition, it is preferable that the area | region between the inner edge of the said brush-like area | region and the said vent hole is given the water-repellent process.
Further, the material of the filament is a thermoplastic resin selected from polyethylene naphthalate, polybutylene terephthalate, polyethylene terephthalate, nylon 6 and nylon 66, and the height of the filament is 3 mm or more and 10 mm or less. Preferably there is.

  It is preferable that an enlarged diameter portion having a diameter larger than that of the base portion and the intermediate portion of the filament is provided at the tip portion of the filament to be erected.

Furthermore, another aspect of the present invention is a tire condition monitoring system.
The system includes a transmission device, a reception device, and a monitoring unit.
The transmitter is
A sensor for detecting a state of gas filled in a tire cavity region surrounded by a tire and a rim as tire information;
A transmitter for wirelessly transmitting the detected tire information;
A wall covering the sensor and the transmitter; an internal space defined by the wall from the tire cavity region; and a vent hole penetrating the wall that communicates the internal space and the tire cavity region. A housing, and
A brush-like region in which a plurality of flexible filaments are erected from the surface of the housing is formed around the vent hole.
The receiving device receives the tire information transmitted from the transmitter.
The said monitoring part determines the presence or absence of abnormality of a tire based on the said tire information, and alert | reports the determination result.

  The transmission device and the tire information monitoring system described above can appropriately measure and acquire tire information such as tire air pressure information even if the tire puncture is repaired using the puncture repair agent.

It is a figure showing the whole tire pressure monitoring system which is one embodiment of a tire information monitoring system. It is a figure explaining an example of the method by which the transmission device shown in FIG. 1 is fixed in a tire cavity area | region. It is a perspective view which shows the whole device with which the transmission device shown in FIG. 2 was integrated with the tire valve. It is arrow sectional drawing of the transmission device along the AA line shown in FIG. It is a circuit block diagram of the transmission device shown in FIG. It is a figure explaining the brush-like field of the transmitting device of this embodiment. (A), (b) is a figure explaining the filament of the brush-like area | region provided in the transmission device of this embodiment. It is a circuit block diagram of the monitoring apparatus shown in FIG.

  Hereinafter, the transmitting apparatus and tire information monitoring system of the present invention will be described in detail.

(Outline of tire pressure monitoring system)
FIG. 1 is a diagram showing an overall outline of a tire pressure monitoring system 10 which is an embodiment of a tire information monitoring system.
A tire pressure monitoring system (hereinafter referred to as a system) 10 is mounted on a vehicle 12. The system 10 includes a pneumatic information transmitting device (hereinafter referred to as a transmitting device) 16a, 16b, 16c, 16d provided in each tire cavity region of the tires 14a, 14b, 14c, 14d of each wheel of the vehicle 12, and a monitoring device 18. And having.

  Each of the transmission devices 16a, 16b, 16c, and 16d detects, as tire information, information related to the air pressure filled in the tire cavity region surrounded by the tire and the rim, and wirelessly transmits the tire information to the monitoring device 18. . Hereinafter, when the transmission devices 16a, 16b, 16c, and 16d are described together, the transmission devices 16a, 16b, 16c, and 16d are collectively referred to as the transmission device 16.

(Transmission device configuration)
FIG. 2 is a diagram illustrating an example of a method in which the transmission device 16 is fixed in the tire cavity region. FIG. 3 is a perspective view showing the entire device in which the transmission device 16 shown in FIG. 2 is integrated with the tire valve 20.
The transmission device 16 is provided at an end portion of the tire valve 20 extending toward the tire cavity region, and the tire valve 20 is mechanically fixed to the rim 19 as shown in FIG. Fixed and arranged.
FIG. 4 is a cross-sectional view of the transmission device 16 taken along the line AA shown in FIG. As illustrated in FIG. 4, the transmission device 16 includes a housing 22 and a circuit 24 provided inside the housing 22. The circuit 24 includes a substrate 26, a sensor unit 28 provided on the substrate 26, a transmitter 30, a processing unit 32, a power supply unit 34, and an antenna 40 (see FIG. 5). The housing 22 is provided with a vent hole 36 that passes through the wall of the housing 2 and communicates between the internal space of the housing 22 and the tire cavity region. A brush-like region 39 in which a large number of filaments 37 are erected from the surface of the housing 22 is formed on the surface of the housing 22 so as to surround the ventilation hole 36. The brush-like region 39 will be described later.

FIG. 5 is a circuit configuration diagram of the transmission device 16.
The sensor unit 28 includes an air pressure sensor 28a and an A / D converter 28b. The air pressure sensor 28a senses the air pressure in the internal space 38 in the housing 22 and outputs a pressure signal. The internal space 38 in the housing 22 communicates with the space in the tire cavity region via a vent hole 36 (see FIG. 4) provided in the housing 22.
The A / D converter 28b digitally converts the pressure signal output from the air pressure sensor 28a and outputs pressure data.

  The processing unit 32 includes a central processing unit 32a and a storage unit 32b. The central processing unit 32a operates based on a program stored in the semiconductor memory of the storage unit 32b. When the central processing unit 32a is driven by being supplied with electric power, the pressure data sent from the sensor unit 28 is air pressure information to the monitoring device 18 via the transmitter 30 at predetermined time intervals, for example, every 5 minutes. Control to send pressure data. Identification information unique to the transmission device 16 is stored in the storage unit 32b in advance, and the central processing unit 32a controls to transmit the identification information together with the pressure data to the monitoring device 18.

  The storage unit 32b includes a ROM in which a program for operating the central processing unit 32a is recorded and a rewritable nonvolatile memory such as an EEPROM. The unique identification information of the transmission device 16 is stored in the non-rewritable area of the storage unit 32b.

The transmitter 30 includes an oscillation circuit 30a, a modulation circuit 30b, and an amplification circuit 30c.
The oscillation circuit 30a generates a carrier wave signal, for example, an RF signal having a frequency of 315 MHz band.
The modulation circuit 30b modulates the carrier wave signal using the pressure data sent from the central processing unit 32a and the identification information unique to the transmission device 16 to generate a transmission signal. As the modulation method, methods such as amplitude shift keying (ASK), frequency modulation (FM), frequency shift keying (FSK), phase modulation (PM), phase shift keying (PSK) can be used.
The amplifier circuit 30c amplifies the transmission signal generated by the modulation circuit 30b. The amplified transmission signal is wirelessly transmitted to the monitoring device 18 via the antenna 40.
For example, a secondary battery is used as the power supply unit 34 and supplies power to the sensor unit 28, the transmitter 30, and the processing unit 32 semipermanently.

  As shown in FIG. 4, the housing 22 that covers the circuit 24 is provided with a vent hole 36 that penetrates a wall that covers the internal space 38 of the housing 22. A brush-like region 39 in which a large number of flexible filaments 37 are provided is provided around the opening of the vent hole 36.

Thus, the brush-like region 39 is provided so that the communication between the internal space 38 of the housing 22 and the tire cavity region is maintained even when the puncture repair agent is injected into the tire cavity region when the tire is punctured. It is to make it. By providing the brush-like region 39 so as to surround the opening of the vent hole 36, the vent hole 36 is less likely to be blocked by the puncture repair agent.
In general, a puncture repair agent is easily cured by receiving vibration or the like due to its properties. For this reason, when the puncture repair agent adheres to the housing 22 and flows in the direction of the air hole 36 along the surface of the housing 22, the puncture repair agent passes through the flexible filament 37 of the brush-like region 39. . At this time, the filament 37 vibrates back and forth and right and left by the rolling of the tire, so that the puncture repair agent is cured by the filament 37. For this reason, the puncture repair agent does not reach the vent hole 36.
Further, since the filament 37 in the brush-like region 39 is flexible, even if the filament 37 protrudes from the surface of the housing 22, it interferes with the rim assembly lever and the tire bead portion when the rim is assembled, thereby preventing the rim assembly. There is nothing.

The material of the filament 37 is, for example, a thermoplastic resin selected from polyethylene naphthalate, polybutylene terephthalate, polyethylene terephthalate, nylon 6, and nylon 66. The filament 37 has a diameter of 1 mm or less. It is preferable at the point which has flexibility.
6 and 7A and 7B show the dimensions of the filament 37 and the brush-like region 39. FIG.
The height B (see FIGS. 7A and 7B) at which the filament 37 stands is preferably 3 mm or more and 10 mm or less. When the height B is less than 3 mm, the flexibility is lost, and the puncture repair agent scattered from above the housing 22 is hard to be cured by the vibration of the filament 37, and as a result, the puncture repair agent is introduced into the vent hole 36. It becomes easy to flow. On the other hand, when the height B exceeds 10 mm, the puncture repair agent is likely to approach the vent hole 36 through the filament 37.
In the brush-like region 39, the density of the filaments 37 is preferably 30 or more per 100 mm ² . When the filaments 37 in the brush-like region 39 are in the above density range, the puncture repair agent stays in the brush-like region 39 and is easily hardened, so that it is difficult to reach the vent hole 36.

The brush-like region 39 is formed in an annular shape around the vent hole 36, and the width C (see FIG. 6) of the annular brush-like region 39 is preferably 10 mm or more. When the width C of the brush-like region 39 is less than 10 mm, the width C is too narrow, and the puncture repair agent flowing from the periphery of the opening of the vent hole 36 on the surface of the housing 22 is sufficiently retained and cured. Furthermore, the ventilation hole 36 is not sufficiently protected against scattering of the puncture repair agent.
The brush-like region 39 is preferably formed in an annular shape around the air hole 36, and the inner edge of the annular brush-like region 39 is preferably 2 mm or more and 10 mm or less away from the edge of the air hole 36. That is, the distance A shown in FIG. 6 is preferably 2 mm or more and 10 mm or less. This is because when the distance A exceeds 10 mm, the puncture repair agent may adhere to the inner region of the brush-like region 39 due to scattering. Further, when the distance A is less than 2 mm, the puncture repair agent attached to the filament 37 located on the inner edge of the brush-like region 39 is likely to move to the vent hole 36 along the filament 37.

  As shown in FIG. 7A, a diameter enlarged portion 37a having a diameter larger than that of the base portion and the intermediate portion of the filament 37 is provided at the tip portion of the filament 37 standing in the brush-like region 39. It is preferable. By providing the filament 37 with the enlarged diameter portion 37a, when the puncture repair agent scatters from above the housing 22 and adheres to the filament 37, it easily adheres to the enlarged diameter portion 37a, and thus adheres to the enlarged diameter portion 37a. The puncture repair agent is easily sandwiched between the enlarged diameter portions 37a of the adjacent filaments 37 and hardened. For this reason, the possibility of reaching the ventilation hole 36 is reduced. As shown in FIG. 7B, the filament 37 may not be provided with the diameter enlarged portion 37a. However, in order to prevent the puncture repair agent from reaching the air holes 36 more effectively, it is preferable that the enlarged diameter portion 37 a is provided in the filament 37.

On the surface of the housing 22, it is preferable that the region between the inner edge of the brush-like region 39 and the air hole 36 (the region indicated by the distance A shown in FIG. 6) is subjected to water repellent treatment.
As the water repellent treatment, for example, a silicone resin, a fluorine resin, or a modified resin grafted with an organic silyl group or a fluoroalkyl group is formed as a film on the surface. In addition, a fine uneven pattern exhibiting water repellency is formed on the surface of the region surrounding the opening of the vent hole 36. Furthermore, the water repellent treatment may be performed on the inner peripheral surface of the vent hole 36. By subjecting the surface of the region surrounding the opening of the vent hole 36 or the inner peripheral surface of the vent hole 36 to water repellency, the puncture repair agent scattered in this region is repelled and the puncture repair agent can adhere. Low. For this reason, the possibility that the puncture repair agent adheres to this region and closes the air hole 36 is extremely reduced.

Note that the transmitting device 16 of the present embodiment detects the air pressure filled in the tire cavity area as an air state, but the object to be detected is the temperature of the air in the tire cavity area in addition to the air pressure. May be. Moreover, the temperature of the air pressure and air in the tire cavity region may be used.
In addition to being fixed to the tire valve 20, the transmission device 16 may be directly fixed to the tire inner surface facing the tire cavity region or the surface of the rim 19 facing the tire cavity region.

(Configuration of monitoring device)
FIG. 8 is a circuit configuration diagram of the monitoring device 18.
The monitoring device 18 is disposed, for example, at the position of the driver's seat of the vehicle 10 and notifies the driver of air pressure information. The monitoring device 18 includes an antenna 52, a reception unit 54, a reception buffer 56, a central processing unit 58, a storage unit 60, an operation unit 62, a switch 64, a display control unit 66, a display unit 68, Power supply unit 70.

The antenna 52 is matched to the same frequency as the transmission frequency of the transmission device 16 and is connected to the reception unit 54.
The receiving unit 54 receives a transmission signal of a predetermined frequency transmitted from the transmission device 16, performs demodulation processing, and extracts pressure data and identification information data. This data is output to the reception buffer 56.
The reception buffer 56 temporarily stores pressure data and identification information data output from the reception unit 54. The stored pressure data and identification information data are output to the central processing unit 58 in accordance with instructions from the central processing unit 58.

  The central processing unit 58 is mainly configured by a CPU and operates based on a program stored in the storage unit 60. The central processing unit 58 monitors the air pressure of the tires 14a to 14d for each identification information based on the received pressure data and identification information data. Specifically, the presence or absence of abnormality of the tires 14a to 14d is determined based on the pressure data, and the determination result is notified to the driver. Determining whether or not there is an abnormality in the tire means, for example, determining whether or not the tire is punctured because the air pressure becomes abnormally low or rapidly decreases in a short time.

The central processing unit 58 outputs the determination result to the display control unit 66 and causes the display unit 68 to output the determination result via the display control unit 66.
Furthermore, the central processing unit 58 performs initial settings such as a communication method with the transmission device 16 in accordance with information from the operation unit 62 and information from the switch 64. Further, based on information from the operation unit 62, a determination condition for determining whether there is a tire abnormality in the central processing unit 58 can be set.
The storage unit 60 includes a ROM that stores a program for operating the CPU of the central processing unit 58 and a nonvolatile memory such as an EEPROM. The storage unit 60 stores a table of communication methods with the transmission device 16 at the manufacturing stage. The transmission device 16 and the monitoring device 18 communicate with each other using a communication method set in advance in the initial stage. The communication method table includes information such as a communication protocol, a transfer bit rate, and a data format corresponding to the unique identification information of each transmission device 16. Such information can be freely changed by input from the operation unit 62.

The operation unit 62 includes an input device such as a keyboard and is used to input various information and conditions. The switch 64 is used to instruct the central processing unit 58 to start the initial setting.
The display control unit 66 controls the display unit 68 to display the tire air pressure corresponding to the mounting positions of the tires 14a to 14d according to the determination result from the central processing unit 58. At that time, the display control unit 66 controls the display unit 68 to simultaneously display a determination result that the tire is in a puncture state.
The power supply unit 70 controls the power supplied from the battery mounted on the vehicle 10 to a voltage suitable for each part of the monitoring device 18 and supplies the power through a power supply line (not shown).
Thus, the transmission device 16 and the monitoring device 18 are configured.

  As described above, since the brush-like region 39 is formed around the opening of the ventilation hole 36 of the casing 22 of the transmission device 16, the possibility that the ventilation hole 36 is blocked by the puncture repair agent is extremely high. Low. For this reason, the communication between the internal space 38 of the housing 22 and the tire cavity region can be maintained.

(Examples 1 to 5, conventional examples)
Hereinafter, in order to investigate the effect of this embodiment, various brush-like regions 39 were produced in the transmission device.
First, the distance A (see FIG. 6) and the height B (see FIGS. 7A and 7B) were variously changed using Examples 1 to 5 and the conventional example.
In each of Examples 1 to 5, the filament 37 is provided on the surface of the housing 22, the thickness of the filament 37 is 0.5 mm, the density of the filament 37 is 50 per 100 mm ² , and the width C of the brush-like region 39 is set. Fixed to 20 mm. Nylon 66 was used as the material of the filament 37.
In the conventional example, the brush-like region 39 is not provided.
When evaluating the transmitting device, a 195 / 65R15 passenger car tire was used, and the tire air pressure was set to 200 kPa. Before performing the drum running test, approximately 450 ml of the puncture repair agent is injected into the tire cavity region, and the value of the air pressure measured by the system 10 decreases by 5% with respect to the correct air pressure, that is, the time until malfunction occurs. Examined.
Table 1 shows the specifications of Examples 1 to 5 and the conventional example and the evaluation results.

  As can be seen from the evaluation results in Table 1, it can be seen that the time until malfunctioning in the conventional examples is overwhelmingly long in Examples 1 to 5, and it is difficult for the puncture repair agent to adhere to the air holes 36. In particular, Example 5 in which the diameter-enlarged portion 37a is provided on the filament 37 does not cause a malfunction of air pressure.

(Examples 6 to 8)
Next, the effect of the thickness (diameter) of the filament 37 was examined.
Examples 6 to 8 in which the thickness of the filament 37 was variously changed were produced. The density, distance A, height B, and width C of the filament 37 in Examples 6 to 8 were aligned with the density, distance A, height B, and width C of the filament 37 of Example 1. Nylon 66 was used as the material of the filament 37.
For the evaluation, the same method as the above evaluation method was used, and the evaluation was performed by the time until the system 10 malfunctioned.
Table 2 below shows the specifications of Examples 6 to 8 and the evaluation results together with Example 1.

  As can be seen from Table 2, in Examples 1, 6, and 7 where the thickness (diameter) of the filament is 1 mm or less, the time until malfunctioning is long. Accordingly, the thickness (diameter) of the filament is preferably 1 mm or less.

(Examples 9 to 11)
Next, the effect of the density of the filament 37 was examined.
Examples 9 to 11 in which the density of the filament 37 was variously changed were produced. The thickness, distance A, height B, and width C of the filament 37 in Examples 9 to 11 were aligned with the thickness, distance A, height B, and width C of the filament 37 in Example 1. Nylon 66 was used as the material of the filament 37.
For the evaluation, the same method as the above evaluation method was used, and the evaluation was performed by the time until the system 10 malfunctioned.
Table 3 below shows the specifications of Examples 9 to 11 and the evaluation results together with Example 1.

As can be seen from Table 3, in Examples 1, 9, and 10 where the density is 30 or more per 100 mm ² , the time until malfunctioning is extremely long compared to Example 11. Accordingly, the density of the filament 37 is preferably 30 or more per 100 mm ² .

(Examples 12 to 14)
Next, the effect of the width C of the brush-like region 39 was examined.
Examples 12 to 14 in which the width C of the brush-like region 39 was variously changed were produced. The thickness, density, distance A, and height B of the filament 37 in Examples 12 to 14 were aligned with the thickness, density, distance A, and height B of the filament 37 of Example 1. Nylon 66 was used as the material of the filament 37.
For the evaluation, the same method as the above evaluation method was used, and the evaluation was performed by the time until the system 10 malfunctioned.
Table 4 below shows the specifications of Examples 12 to 14 and the evaluation results together with Example 1.

  As can be seen from Table 4, in Examples 1, 12, and 13 in which the width C is 10 mm or more, the time until malfunctioning is extremely long compared to Example 14 in which the width C is less than 10 mm. Accordingly, the width C is preferably 10 mm or more.

  The transmission device and the tire information monitoring system according to the present invention have been described in detail above. However, the transmission device and the tire information monitoring system according to the present invention are not limited to the above-described embodiment, and various types can be used without departing from the gist of the present invention. Of course, improvements and changes may be made.

DESCRIPTION OF SYMBOLS 10 Tire pressure monitoring system 12 Vehicle 14,14a, 14b, 14c, 14d Tire 16,16a, 16b, 16c, 16d Air pressure information transmission device 18 Monitoring device 19 Rim 20 Tire valve 22 Case 24 Circuit 26 Substrate 28 Sensor unit 28a Air pressure Sensor 28b A / D converter 30 Transmitter 32 Processing unit 34 Power supply part 36 Ventilation hole 37 Filament 37a Diameter enlarged part 38 Internal space 39 Brush-like area 40 Antenna 42 Opening part 52 Antenna 54 Reception part 56 Reception buffer 58 Central processing part 60 Storage unit 62 Operation unit 64 Switch 66 Display control unit 68 Display unit 70 Power supply unit

Claims (9)

A transmitting device that is provided in a tire cavity region and transmits tire information related to a tire state,
A sensor for detecting a state of gas filled in a tire cavity region surrounded by a tire and a rim as tire information;
A transmitter for wirelessly transmitting the detected tire information;
A wall covering the sensor and the transmitter; an internal space defined by the wall from the tire cavity region; and a vent hole penetrating the wall to communicate the internal space and the tire cavity region. A housing, and
A transmitting device, wherein a plurality of flexible filaments are provided around the air hole so that a plurality of flexible filaments are erected from the surface of the housing.   The transmission according to claim 1, wherein the filament is made of a thermoplastic resin selected from polyethylene naphthalate, polybutylene terephthalate, polyethylene terephthalate, nylon 6, and nylon 66, and the filament has a diameter of 1 mm or less. apparatus. Density of the filaments of the brush-like region is greater than or equal to 30 lines per 100 mm ^2, transmission apparatus according to claim 2.   The transmission device according to claim 1, wherein the brush-like region is formed in an annular shape around the vent hole, and the width of the annular brush-like region is 10 mm or more.   The brush-like region is formed in an annular shape around the vent hole, and an inner edge of the annular brush-like region is 2 mm or more and 10 mm or less away from the vent hole. The transmitter according to the item.   The transmission device according to claim 5, wherein a region between an inner edge of the brush-like region and the air hole is subjected to water repellent treatment.   The material of the filament is a thermoplastic resin selected from polyethylene naphthalate, polybutylene terephthalate, polyethylene terephthalate, nylon 6, and nylon 66, and the height of the filament is 3 mm or more and 10 mm or less. The transmission device according to any one of claims 1 to 6.   The transmitting apparatus according to claim 1, wherein a diameter-enlarged portion having a diameter larger than that of the base portion and the intermediate portion of the filament is provided at a tip portion of the filament to be erected. . A tire condition monitoring system,
The system includes a transmission device, a reception device, and a monitoring unit,
The transmitter is
A sensor for detecting a state of gas filled in a tire cavity region surrounded by a tire and a rim as tire information;
A transmitter for wirelessly transmitting the detected tire information;
A wall covering the sensor and the transmitter; an internal space defined by the wall from the tire cavity region; and a vent hole penetrating the wall that communicates the internal space and the tire cavity region. A housing, and
Around the vent hole, a brush-like region is formed in which a plurality of flexible filaments are erected from the surface of the housing,
The receiving device receives the tire information transmitted from the transmitter,
The said monitoring part determines the presence or absence of abnormality of a tire based on the said tire information, and alert | reports the determination result, The tire condition monitoring system characterized by the above-mentioned.