JP5099823B2 - Tire monitoring system - Google Patents

Description

  The present invention relates to a technique for monitoring whether or not the air pressure of a tire of a vehicle, for example, a tire attached to a run flat wheel, has decreased.

The run flat wheel is configured so that when the tire is punctured, the inner surface of the ground contact portion of the tire hits the core, and is applied to a passenger car, a bus, a truck, and the like.
In a normal wheel that is not a run-flat wheel, when the pressure in the tire is reduced due to puncture, the inner surface of the tire contact portion hits the rim. When the inner surface of the tire's ground contact part hits the rim, especially when the inner surface of the front tire's contact part hits the rim, the so-called "handle is taken" is instantaneously maintained and the vehicle posture is maintained. It becomes difficult.

  On the other hand, in the run flat wheel system, even if puncture occurs, the inner surface of the tire is in contact with the core and the vehicle is kept in a certain position (for example, a passenger car). For example, about 100 km: even a large truck can travel about 30 km).

FIG. 10 schematically shows a run flat wheel system, and FIG. 11 shows a cross section of the run flat wheel system.
10 and 11, the run flat wheel system 4J includes a wheel body 40, a core 44, and a tire 45. The core 44 is formed by dividing an annular member into, for example, six equal parts in the circumferential direction in the example of FIG. 10, and the six divided members 440 divided into six equal parts are adjacent divided members. 440 and a connecting member (not shown) are combined to form an annular shape.
As shown in FIG. 11, the core 44 integrally formed in an annular shape is in contact with the rim outer peripheral surface 41 o at the center of the wheel 40 in the width direction of the rim 41.
In FIG. 10, the symbol B indicates a division location in the circumferential direction of the core 44.
In FIG. 11, reference numeral 42 indicates a disk, and reference numeral 46 indicates an inflator valve.

The run flat wheel system 4J is very effective in an area where the road condition is bad or an area where the tire cannot be changed on the spot. Even if a vehicle traveling in such an area punctures the tire 45 at night, for example, it can travel to a safe place and replace the puncture without replacing the tire 45 at that location. It is.
Moreover, even if the tire 45 is bursted or the like, even if the air escapes instantaneously, it is possible to travel to a safe place.

Furthermore, if the run-flat wheel system 4J is adopted, even if the tire pressure becomes zero, the position of the vehicle is maintained and it remains as it is up to a certain distance (about 100 km for passenger cars and about 30 km for large trucks). It is possible to run.
That is, if the run flat wheel system 4J is employed, even if the tire is punctured, it is possible to travel to a place where there is a repair facility without replacing it with a spare tire on the road shoulder or the like. Therefore, it is possible to omit the spare tire itself if the traveling is within a limited range.

  If the spare tire can be omitted, the spare tire storage space in the vehicle can be omitted and the spare tire can be used effectively. In particular, in so-called “hybrid vehicles” and “natural gas vehicles”, auxiliary equipment such as gas tanks occupy space, so that there is a great merit that the spare tire storage space can be omitted.

  Further, if the spare tire itself can be omitted, it is not necessary to discard the spare tire, and it is not necessary to incinerate the spare tire. Therefore, the effect of reducing CO2 can be obtained.

Here, even when the air pressure of the tire attached to the run-flat wheel is reduced and the inner surface of the grounding portion of the tire comes into contact with the core, the driver often does not notice. In particular, when the rear wheel is punctured, the driver often does not notice even if the inner surface of the ground contact portion of the tire of the rear wheel hits the core.
Even if the inner surface of the tire's ground contact part hits the core, if the driver keeps running without noticing that, the tire may burst, which is dangerous.

Even in a normal wheel instead of a run-flat wheel, it is dangerous that the tire air pressure is too low when the vehicle travels, which adversely affects traveling.
For this reason, particularly in a run-flat wheel, it is necessary to mount a system for monitoring the air pressure in the tire in order to ensure safety in vehicle travel.

In the prior art, tire pressure monitoring systems exist. Such a technique is also applied to a general tire (other than a tire attached to a run-flat wheel), and is widely used.
Such a tire air pressure monitoring system includes, for example, a sensor that detects the air pressure in the tire, a monitor device that monitors the air pressure in the tire based on the detection result, and the detection result of the sensor wirelessly to the receiver of the monitor device. The sensor and the transmission device are provided in each tire (see Patent Document 1).

However, the conventional monitoring systems (including the system disclosed in Patent Document 1) have a problem that the cost for introducing them becomes too high.
Since the air pressure in the changing tire must be measured and the measurement result must be constantly transmitted as a radio wave signal, a high-end digital circuit must be used. Therefore, the sensor module (radio wave transmission device) attached to the tire side becomes expensive, and the entire system becomes expensive.

In addition to the fact that the run flat wheel itself is expensive (compared to a normal wheel that is not a run flat wheel), the system that monitors the air pressure in the tire is also expensive, so that the vehicle using the run flat wheel The price of will also be expensive. As a result, the spread of the run flat wheel itself is hindered.
JP 2004-145474 A

  The present invention has been proposed in view of the above-described problems of the prior art, and is a tire monitoring system that can reliably detect that the tire air pressure has become too low without increasing the introduction cost. The purpose is to provide.

  According to the present invention, the air pressure of the tire (45) decreases at the core (44) of the rim (41) of the wheel (4), and the ground contact portion (45a) of the tire (45) contacts the rim (41) side. Touch sensor (5, 5S) that senses the effect, temperature sensor (6) that measures the temperature of the internal space (45i) of the tire (45), detection results of the touch sensor (5, 5S), and temperature sensor Transmitters (7, 16, 17) that transmit the detection results of (6) as radio signals (So1, So11) to the chassis (3) side are provided, and a battery (73) is provided on the chassis (3) side, And the receiver (8) which receives the radio signal (So1, So11) transmitted from the transmitter (7, 16, 17) of the wheel (4), and the radio signal (So1, So11) received by the receiver (8). ) To the ground contact part (45a) of the tire (45) In the tire monitoring system having the control device (9) configured to determine whether or not the touch (41) side is touched, the sensing unit (50) of the touch sensor (5, 5S) includes a core ( 44) is located radially outward from the outer edge portion (44a), and the control means (9) indicates that the grounding portion (45a) of the tire (45) is in contact with the touch sensor (5, 5S). It is determined whether or not a signal is received (S1). If the signal is received, it is determined whether or not the speed signal of the speedometer (12) is equal to or higher than a predetermined speed (S2). If it is equal to or greater than a predetermined value, it is determined that the tire is rolling, and it is determined whether or not a signal indicating contact from the touch sensor (5, 5S) continues for a predetermined time (S3). If this continues, the grounding part (45 of the tire (45) ) Warns that it has contacted the core (44) (S4), receives a measurement signal from the temperature sensor (6) (S5), and whether the temperature inside the tire (45i) is equal to or higher than the threshold temperature. (S6), and if it is equal to or higher than the threshold temperature, it has a function of warning that the tire internal temperature has risen to the dangerous area.

According to the invention, the temperature sensor (6) is provided in the space (44i) inside the core (44).

According to the present invention having the above-described configuration, even if the rear wheel that is difficult for the driver to grasp that the air has escaped is punctured, the grounding portion (45a: more specifically, the inner surface of the grounding portion) of the tire (45) The touch sensor (5) detects that the wheel (4) is in contact with the rim (41) side (in the case of a run-flat tire, the core 44 provided on the rim 41) and warns the driver.
As a result, the driver can immediately know that the air from the tire (45) has escaped, and therefore, the driver can move to the tire repair facility and promptly repair the tire (45).
In other words, the contact portion (45a: more specifically, the inner surface of the contact portion) of the tire (45) is in contact with the rim (41) side of the wheel (4) (or the core 44 of the run-flat tire). It is reliably prevented in the present invention that the tire (45) bursts while running without being noticed.

Here, the touch sensor (5) outputs a measurement signal only when the grounding portion (45a: more specifically, the inner surface of the grounding portion) of the tire (45) is in contact with the sensing portion (50) of the touch sensor (5). Since power is output, power consumption is achieved when the grounding part (45a: more specifically, the inner surface of the grounding part) of the tire (45) is not in contact with the rim (41) side (or the core 44) of the wheel (4). There is almost no. Therefore, according to the present invention, compared with the case where a conventional air pressure sensor is used, the power consumption is small, and the life of the battery as the power source can be prolonged.
Moreover, according to the present invention, it is not necessary to constantly measure the air pressure in the changing tire, and it is not necessary to constantly transmit the measurement result as a radio wave signal. There is no need to use. Therefore, according to the present invention, the entire tire monitoring system can be introduced at low cost.

Here, if the tire (45) continues to travel with the ground contact portion (45a: more specifically, the inner surface of the ground contact portion) in contact with the core (44) or the rim (41) side of the wheel (4), 45), the temperature of the space inside the tire rises due to frictional heat between the ground contact portion (45a: more specifically, the inner surface of the ground contact portion) and the core (44) or the rim (41) of the wheel (4).
The temperature of the tire internal space (45i) is caused by frictional heat between the ground contact portion (45a: more specifically, the inner surface of the ground contact portion) of the tire (45) and the core (44) or the rim (41) of the wheel (4). Ascending means that the tire (45) itself is sandwiched between the road surface and the core (44) or the rim (41) of the wheel (4), and a certain amount of time has passed with an excessive load applied. This means that the risk of the tire (45) bursting has increased.
In the present invention, since the temperature sensor (6) is provided, the tire (45) bursts by detecting that the temperature of the tire internal space (45i) has reached a predetermined temperature (above the threshold temperature). Since the driver can be warned that the danger has increased, it can greatly contribute to the safe driving of the vehicle.

That is, if the temperature sensor (6) is provided in the present invention, the touch sensor (5) allows the rim (41) side (or the core 44) and the grounding portion (45a: more specifically, the grounding portion) of the tire (45). The driver can be warned that the inner surface is in contact, and the temperature sensor (6) can warn the driver that the risk of bursting of the tire (45) has increased.
In this manner, the touch sensor (5) and the temperature sensor (6) provide a double warning to the driver, whereby the air pressure of the tire (45) decreases, and the grounding portion (45a) of the tire (45) is reduced. : More specifically, even if the inner surface of the grounding part hits the rim (41) side (or the core 44), the driver keeps running without noticing it, and the tire (45) bursts. It can be prevented beforehand.

In addition, like the touch sensor (5), the temperature sensor (6) does not output a signal unless the tire internal space temperature becomes higher than the threshold value. Compared to pneumatic sensors that always output signals, power consumption is extremely low.
Therefore, even if the touch sensor (5) and the temperature sensor (6) are provided in parallel, the battery life can be prolonged as compared with the case where a conventional tire pressure sensor is used.

Embodiments of the present invention will be described below with reference to FIGS.
1 to 9, members similar to those in FIGS. 10 and 11 are described with the same reference numerals.
First, a first embodiment of the present invention will be described with reference to FIGS.

  The tire monitoring system according to the first embodiment is generally indicated by reference numeral 100 in FIG. 1 when applied to, for example, a freight vehicle. FIG. 2 shows details of the tire monitoring system shown in FIG. 1 excluding the freight vehicle 1. In FIG. 3, only the wheel and the tire and only the members necessary for monitoring the air pressure in the tire are schematically shown.

In FIG. 1, the tire monitoring system 100 according to the first embodiment is applied to a freight vehicle 1. The freight vehicle 1 has a cab (cab) 2, a chassis 3, and a wheel 4.
The tire monitoring system 100 includes a touch sensor 5, a temperature sensor 6, and a transmitter 7 in a tire 45 of the wheel 4 (see FIG. 5). The tire monitoring system 100 includes a receiver 8 on the chassis 3 side, and includes a control device 9 and a warning device 10 on the cab (cab) 2 side.

In FIG. 2, the transmitter 7 includes a power supply control unit 71, a high frequency transmission unit 72, and a battery 73.
The touch sensor 5 and the temperature sensor 6 are connected to the transmitter 7 by connection (wire harness) Li. The touch sensor 5, the temperature sensor 6 and the transmitter 7 use the battery 73 in the transmitter 7 as an operating power source.
The receiver 8, the control device 9, and the warning device 10 are supplied with power from the battery 11 mounted on the chassis 3.
The control device 9 is connected to the ACC (accessory) position of the speedometer 12 and the key switch 13. The speedometer 12 may not be connected depending on the vehicle application.

As shown in FIGS. 2 and 3, the detection results of the touch sensor 5 and the temperature sensor 6 are transmitted as a radio wave signal (arrow So1) from the high frequency transmitter 72 in the transmitter 7 and received by the receiver 8 on the chassis 3 side. Is done. Then, it is sent to the control device 9.
The control device 9 performs necessary control based on the detection results of the touch sensor 5 and the temperature sensor 6, the air pressure of the tire 45 decreases, and the ground contact portion 45 a (the inner surface) of the tire 45 is connected to the core 44 or the rim 41. In the case of touching, the warning device (for example, warning lamp) 10 in the cab 2 warns that effect. The details of the monitoring control will be described later with reference to FIG.

As shown in FIG. 3, sensors (touch sensor 5 and temperature sensor 6) are provided on each wheel 4. The radio signal So1 transmitted from the high-frequency transmitter 72 of the transmitter 7 provided on each wheel 4 is detected by the receiver 8 provided on the chassis 3 side corresponding to each wheel 4. That is, as shown in FIG. 4, the number of the receivers 8 on the chassis 3 side is provided by the number of the wheels 4, and the radio signal So1 transmitted from the high frequency transmitter 72 provided in each wheel 4 is received by the corresponding reception. Received by the device 8.
If comprised in this way, in the control apparatus 9, it will be able to determine easily and correctly which air pressure of the tire 45 of the wheel 4 decreased and the ground contact part 45a of the tire 45 and the core 44 or the rim | limb 41 contacted. I can do it.

  It is not preferable to set the distance between the transmitter 7 provided on each wheel 4 and the receiver 8 on the chassis 3 side to be longer than necessary. Since the chassis 3 uses a lot of metal plates, if the distance between the transmitter 7 and the receiver 8 is longer than necessary, the radio signal So1 from the transmitter 7 is blocked by the metal material of the chassis 3. is there.

According to the first embodiment, the touch sensor 5 indicates that the ground contact portion 45a of the tire 45 has contacted the core 44 or the rim 41 even if the rear wheel 4 that is difficult for the driver to grasp that the air has escaped is punctured. It is detected and notified to the driver by the warning device 10 in the cab 2. Therefore, the driver can quickly change or repair the tire 45 by moving to a safe place where the tire can be changed or a place where there is a tire repair facility.
In other words, it is possible to prevent the tire 45 from bursting by running without being noticed (by the driver) that the ground contact portion 45a of the tire 45 is in contact with the core 44 or the rim 41.

Here, the touch sensor 5 outputs a measurement signal only when the grounding portion 45 a of the tire 45 comes into contact with the sensing portion 50 of the touch sensor 5. When the air pressure of the tire 45 is not lowered and the ground contact portion 45a of the tire 45 is not in contact with the core 44 or the rim 41, there is almost no power consumption.
Therefore, compared with the prior art in which the air pressure sensor is always operating, the power consumption is small, and the life of the power source (for example, the battery 73) can be prolonged.
The transmitter 7 is preferably a circuit that transmits a radio wave signal only when the grounding portion 45a of the tire 45 contacts the touch sensor 5 and the touch sensor 5 detects the contact.

In FIG. 5 showing the details of the core 44 of the run flat wheel 4, the touch sensor 5 and the temperature sensor 6, the sensing unit 50 of the touch sensor 5 is an outer edge of the core 44 (radially outward surface: upward in FIG. 5). It is provided at a position radially outward (upward in FIG. 5) from the edge 44a.
Thereby, the touch sensor 5 detects that the tire pressure is reduced and the tire 45 is contracted before the inner portion of the portion 45a (grounding portion) 45a that contacts the road surface of the tire 45 contacts the core 44. can do.
Even if the ground contact portion 45a of the tire 45 and the core 44 or the rim 41 come into contact with each other, the detection can be continued in the same manner.

  In FIG. 5, the wheel (run flat wheel) 4 includes a wheel body 40, a tire 45, and a core 44. The wheel body 40 includes a rim 41 and a disk 42, and an inflator valve 46 is attached to one place of the rim 41.

As described above, the sensing unit 50 in the touch sensor 5 protrudes outward in the radial direction (upward in FIG. 5) from the outer edge portion 44 a of the core 44. For this reason, the air pressure of the tire 45 decreases due to puncture or other factors, and the inner portion of the portion 45a where the tire 45 contacts the road surface (grounding portion) 45a contacts the sensing unit 50 in the touch sensor 5 before hitting the core 44. To do.
When the ground contact portion 45 a of the tire 45 comes into contact with the sensing portion 50 of the touch sensor 5, the touch sensor 5 detects that fact and sends a detection signal from the transmitter 7. The signal is received by the receiver 8 on the chassis 3 side and sent to the control device 9.
As a result, when the air pressure of the tire 45 decreases and the grounded side of the tire 45 is recessed, it is possible to warn and notify the vehicle driver before the tire 45 hits the core 44.

Although not shown, when the monitoring system according to the first embodiment is applied to a normal wheel (wheel having no core) that is not a run-flat wheel, the touch sensor 5 and the temperature sensor 6 are used. Although the touch sensor 5 is attached to the rim 41, the inner part of the portion 45 a that contacts the road surface of the tire 45 is in a stage before the contact with the rim 41. 50 is preferably configured to come into contact.
For example, it is preferable to form a pedestal (portion protruding outward in the radial direction of the wheel) on the rim 41 and provide the touch sensor 5 on the pedestal.

  With such a configuration, when the air pressure of the tire 45 decreases due to puncture or other factors and the grounded side of the tire 45 is recessed, the inner portion of the tire 45 contacting the road surface (grounding portion) 45a becomes the rim 41. Before the contact, the inner portion of the grounding portion 45a of the tire 45 contacts the sensing unit 50 of the touch sensor 5, and the contact is detected. As a result, it is possible to warn the driver that the air pressure of the tire 45 has dropped and is about to come into contact with the rim 41.

Similarly to the touch sensor 5, the temperature sensor 6 described later does not output a signal unless the tire internal space temperature becomes higher than the threshold value. Compared to pneumatic sensors that always output signals, power consumption is extremely low.
Therefore, even if the touch sensor 5 and the temperature sensor 6 are provided in parallel, the life of the battery 73 of the transmitter 7 can be extremely prolonged as compared with the case of a conventional tire pressure sensor.

  In the first embodiment, it is not necessary to constantly measure the air pressure in the fluctuating tire, and it is not necessary to constantly transmit the measurement result as a radio wave signal, so a high-grade electronic circuit such as a conventional air pressure sensor is used. There is no need to do. Therefore, the entire tire monitoring system can be introduced at a low cost.

As shown in FIGS. 1 and 2, each wheel 4 is provided with a temperature sensor 6 in addition to the touch sensor 5.
As shown in FIG. 5, the temperature sensor 6 is provided, for example, in a space 44 i inside the core 44, but the temperature sensor 6 may be provided inside the transmitter 7 (see FIGS. 1 and 2).
The mounting position of the temperature sensor 6 is not particularly limited as long as it can detect that the temperature of the air inside the tire 45 has increased and the temperature sensor 6 is less likely to be damaged. .
Similarly to the temperature sensor 6, the transmitter 7 is provided in a space 44 i inside the core 44. The transmitter 7 is preferably attached so that the high-frequency transmitter 72 can easily transmit a radio signal toward the chassis-side receiver 8.

If the vehicle continues to run with the inner surface of the ground contact portion 45a of the tire 45 in contact with the core 44, the temperature of the inside 45i of the tire 45 rises due to frictional heat between the inner surface of the ground contact portion 45a of the tire 45 and the core 44. .
Here, the friction between the inner surface of the ground contact portion 45a of the tire 45 and the core 44 can be suppressed by the lubricant. However, if the vehicle keeps running with the inner surface of the ground contact portion 45a of the tire 45 in contact with the core 44, the lubricant disappears. As a result, the temperature of the inside 45i of the tire 45 rises due to friction between the core 44 and the inner surface of the ground contact portion 45a of the tire 45.

The fact that the temperature of the inside 45i of the tire 45 rises due to frictional heat between the inner surface of the ground contact portion 45a of the tire 45 and the core 44 means that the ground contact portion 45a itself of the tire 45 is sandwiched between the road surface and the core 44, This means that a certain amount of time has elapsed under an excessive load, and the risk that the tire 45 will burst or heat crack has increased.
A temperature sensor 6 is provided to detect that the temperature inside the tire 45i has reached a predetermined temperature (above the threshold temperature) and warn the driver that the possibility of the tire 45 causing bursts and heat cracks has increased. Thus, this is extremely effective from the viewpoint of safe driving of the vehicle 1.

That is, according to the illustrated embodiment, the touch sensor 5 warns the driver that the core 44 and the ground contact portion 45a of the tire 45 are in contact, and the temperature sensor 6 increases the risk of the tire 45 bursting. You can warn the driver.
As described above, the touch sensor 5 and the temperature sensor 6 provide a double warning to the driver, whereby the air pressure of the tire 45 due to puncture or the like decreases, and the grounding portion 45a of the tire 45 hits the core 44. However, it is possible to prevent the driver from continuing to run without noticing it and the tire 45 from bursting.

As the temperature sensor 6, a type having vibration resistance is preferable.
Here, the temperature sensor 6 does not have to be highly sensitive (sensitive). For example, a bimetal method may be used.
Further, as the temperature sensor 6, a thermistor, a thermocouple, or the like may be used.

  Although not shown, when the monitoring system according to the embodiment is applied to a normal wheel (wheel having no core) that is not the run-flat wheel 4, the temperature sensor 6 is provided on the rim 41. Alternatively, it is possible to form a pedestal (a portion protruding outward in the radial direction of the wheel) on the rim 41 and provide the pedestal on the pedestal.

Here, the radio signal So1 (see FIGS. 2 and 3) transmitted from the transmitter 7 of each wheel 4 is emitted from the region on the side of the tire 45 (the region in the direction of arrow S in FIG. 5), and the chassis 3 Is received by the receiver 8 on the side. From the region where the tire 45 is in contact with the road (the region where the steel cord 45b is embedded in FIG. 5, the region in the direction of the arrow R), the radio signal So1 is difficult to be emitted.
This is because the steel cord 45b embedded in the region of the tire 45 in the direction of arrow R acts as a radio wave shield (Faraday shield), so that the radio wave is shielded in the region of the tire 45 in the direction of arrow R.

As shown in FIG. 5, in the run flat wheel 4, the rim 41 is preferably configured as a multi-piece rim.
This is because the core 44 and the tire 45 can be easily attached to the rim 41 in the case of a multi-piece rim.
Note that the rim 41 may be an integral structure as long as the core 44 can be easily attached to the rim 41 together with the tire 45.

Next, the control in the first embodiment shown in FIGS. 1 to 5 will be described with reference to the flowchart of FIG.
In step S <b> 1 of FIG. 6, the control means 9 determines whether or not a signal indicating that the ground contact portion 45 a of the tire 45 has contacted has been received from the touch sensor 5. If a signal indicating that the ground contact portion 45a of the tire 45 is in contact is received (step S1 is YES), it is determined whether or not the speed signal of the speedometer 12 is equal to or higher than a predetermined speed (step S2).

If the speed signal of the speedometer 12 is equal to or higher than the predetermined speed (YES in step S2), for example, it is determined that the tire is rolling or running, and the process proceeds to step S3.
In step S3, it is determined whether or not a signal (contact signal) indicating that a touch has been made from the touch sensor 5 continues for a predetermined time or more. When the signal indicating that the touch sensor 5 has made contact has continued for a predetermined time or longer (YES in step S3), the process proceeds to step S4.

In step S2, if the speed signal of the speedometer 12 is slower than the predetermined speed (NO in step S2), for example, it is determined that the tire is not rolling or is in a stopped state, and step Return to S1.
In step S3, when the time that the signal indicating contact from the touch sensor 5 continues is shorter than the predetermined time (step S3 is NO), the process returns to step S1 as well.
As a case where NO is determined in step S2 or step S3, for example, there is a case where the vehicle is stopped in a state where the tire 45 rides on a step or a cat's eye marker. In such a case, the ground contact portion 45a of the tire 45 is pressed by a step or a cat's eye marker, and the ground contact portion 45a of the tire 45 contacts the touch sensor 5 even though the air pressure of the tire 45 does not decrease. Will be. By providing step S2 and step S3, it is possible to prevent erroneous determination that the tire air pressure has decreased in such a case (when the tire 45 has stopped on a step or a cat's eye marker).
Although not shown, step S2 can be omitted.

In step S4, the warning device 10 warns that the ground contact portion 45a of the tire 45 has touched the touch sensor 5, and then proceeds to step S5.
In step S1, if no signal indicating that the ground contact portion 45a of the tire 45 has contacted is received from the touch sensor 5 (NO in step S1), the process proceeds to step S5 as it is.

In step S5, the control means 9 determines whether or not a measurement signal has been received from the temperature sensor 6 to the effect that the temperature inside the tire 45i has reached a predetermined temperature (threshold temperature or higher). If a measurement signal indicating that the temperature inside the tire 45i has reached a predetermined temperature (threshold temperature or higher) is received (step S5 is YES), the process proceeds to step S6.
On the other hand, if a measurement signal indicating that the temperature inside the tire 45i has reached a predetermined temperature (threshold temperature or higher) has not been received (NO in step S5), the process proceeds to step S9.

In step S6, the control means 9 determines whether or not the measured temperature measured by the temperature sensor 6 exceeds a threshold value. If the measured temperature exceeds the threshold value (YES in step S6), the warning device 10 warns that the tire internal temperature has risen to the dangerous area (step S7), and proceeds to step S8.
On the other hand, if the measured temperature does not exceed the threshold value (step S6 is NO), the process proceeds to step S9.

  In step S8, the control means 9 determines whether or not to end the control. If the control is to be ended (YES in step S8), the control is ended as it is, and if the control is to be continued (NO in step S8), the process returns to step S1, and step S1 and subsequent steps are repeated.

  In step S9, the control means 9 determines whether or not the key switch 13 is OFF. If the key switch 13 is OFF (step S9 is YES), the control is terminated. On the other hand, if the key switch 13 is not OFF (step S9 is NO), the process returns to step S1, and step S1 and subsequent steps are repeated.

Although not explicitly shown in FIG. 6, in step S <b> 1, a measurement signal from the touch sensor 5 (a signal that the tire 45 has pressed the sensing unit 50 of the touch sensor 5) is given for a certain time (for example, 10 seconds) or more. Only when it is continuously received, it is determined that the tire air pressure has decreased and the ground contact portion of the tire has contacted the core.
When the tire 45 gets on various steps on the road during traveling, the ground contact portion 45a of the tire 45 may come into contact with the sensing portion 50 of the touch sensor 5. In such a case, “the air pressure decreases. This is to eliminate the possibility of malfunctioning.
“Continuously” means that the signal when the touch sensor 5 comes into contact with the grounding portion 45a of the tire 45 is continuously received without interruption, or the touch sensor 5 is connected to the grounding portion 45a of the tire 45. This means a state in which a signal indicating contact has been continuously transmitted in pulses (a state in which such pulse signals are intermittently received over a predetermined time).

In FIG. 6, the measurement signal from the temperature sensor 6 is processed after the measurement signal from the touch sensor 5 is processed, but the order is reversed and the measurement signal from the temperature sensor 6 is processed before the touch. The measurement signal from the sensor 5 may be processed.
Furthermore, the measurement signal processing from the touch sensor 5 and the measurement signal processing from the temperature sensor 6 are not executed in series, but the measurement signal processing from the touch sensor 5 and the measurement signal processing from the temperature sensor 6 are performed in parallel. It can also be configured to execute. When measurement signal processing is performed in parallel as described above, for example, when an excessive load is continuously applied to the tire by continuous traveling, or when traveling with a high frequency of using the brake is performed, Since the temperature becomes high, a warning can be given to the driver by the temperature sensor 6, which is effective.

A first modification of the first embodiment is shown in FIG.
In the modified example of FIG. 7, the switch 5 </ b> S is used instead of the touch sensor 5 to detect that the ground contact portion 45 a of the tire 45 has contacted the core 44.

The switch 5S includes a tire side terminal 5A and a core side terminal 5B.
The tire-side terminal 5A is attached to the inner side (the inner side of the tread portion 45t) where the tire 45 contacts the road surface.
The core-side terminal 5B is provided on the outer peripheral side of the core 44 (upper side in FIG. 7) and at a position where it comes into contact with the tire-side terminal 5A when the air pressure of the tire 45 decreases.
If the mounting position of the switch 5S is easy to mount and not easily damaged, the axial direction inner side (inner side with respect to the central axis CL direction) of the core 44 relative to the core 44 is also axially outer side (with respect to the central axis CL direction). It may be outside).

When the tire 45 is punctured, the tire side terminal 5A and the core side terminal 5B come into contact with each other, and a current flows through the circuit 5F. When a current flows through the circuit 5F, a radio signal (radio signal So1 in FIGS. 1 to 3) is transmitted from the transmitter 5C.
Here, in order to prolong the life of the battery 5E, a current flowing when the circuit 5F is closed by disposing the resistor 5D in series with the switch (the tire side terminal 5A and the core side terminal 5B) on the circuit 5F. Is preferably reduced.

  Other configurations and operational effects in the first modification are the same as those of the first embodiment shown in FIGS.

This will be described with reference to FIG. 12 which is another modification of FIG. 5 and FIG. 13 which is a modification of FIG.
5 and 7, the attachment position of the touch sensor 5 is a position that protrudes outward with respect to the core 44 in the axial direction (in the direction of the central axis CL in FIG. 7, hereinafter the same). On the other hand, as shown in FIGS. 12 and 13, the touch sensor 5 can be attached to the core 44 at a position that does not protrude outward in the axial direction.
Although not clearly shown in FIGS. 12 and 13, the core 44 may have a box-shaped cross section or other cross-sectional shapes.
Other configurations and operational effects of FIGS. 12 and 13 are the same as those shown in FIGS.

FIG. 14 shows still another modification of FIG.
In FIG. 7, the electrode 5 </ b> A is attached to the inner surface side of the grounding portion 45 a of the tire 45. In contrast, in FIG. 14, the electrode 5 </ b> A is arranged at a position close to the electrode 5 </ b> B on the core 44 side, not on the inner surface side of the ground contact portion 45 a of the tire 45.
Here, the electrode 5A and the electrode 5B may constitute a sensor as a unit.
Other configurations and operational effects in FIG. 14 are the same as those shown in FIG.

  7, 13, and 14, the electrodes 5 </ b> A and 5 </ b> B of the contact sensor 5 are configured as band-like electrodes extending in the circumferential direction of the core 44 (direction along the tire grounding portion 45 a). Also good.

8 and 9 show a second embodiment of the present invention.
In the first embodiment shown in FIGS. 1 to 7, a battery 73 serving as a driving power source for the sensors 5 and 6 and the transmitter 7 is provided on the wheel 4 side. In the second embodiment shown in FIGS. No battery is provided on the 4 side.

8 and 9, the touch sensor measurement signal transmitter 16, the temperature sensor measurement signal transmitter 17, and the radio wave are provided on the wheel 4 side instead of the transmitter 7 in the first embodiment of FIGS. 1 to 7. / Current converter 18 and capacitor 22 are provided. On the other hand, a radio wave transmitter 19 is provided on the chassis 3 side.
The radio wave / current converter 18 is configured to receive the radio wave So2 transmitted from the radio wave transmitter 19 on the chassis 3 side and convert it into a current. Then, the current converted by the radio wave / current converter 18 is stored as an electric charge by the capacitor 22 interposed in the wheel-side circuit 20.
Here, the radio wave transmitter 19 on the chassis 3 side is provided at a location corresponding to the radio wave / current converter 18 in each wheel 4.

The touch sensor 5, the temperature sensor 6, the touch sensor measurement signal transmitter 16, and the temperature sensor measurement signal transmitter 17 are activated by the electric charge stored in the capacitor 22.
The measurement result of the touch sensor 5 is transmitted from the touch sensor measurement signal transmitter 16 to the receiver 8 on the chassis 3 side as a radio wave signal So11.
The measurement result of the temperature sensor 6 is transmitted from the temperature sensor measurement signal transmitter 17 to the receiver 8 on the chassis 3 side as a radio wave signal So12.

  According to the second embodiment shown in FIGS. 8 and 9, the radio wave So2 transmitted from the chassis 3 side is converted into a current by the radio wave / current converter 18 and stored in the capacitor 22, and the touch sensor 5 and the temperature sensor 6 are stored. The operation power source of the touch sensor measurement signal transmitter 16 and the temperature sensor measurement signal transmitter 17 is used. Therefore, it is not necessary to provide a battery on the wheel 4 side.

  Other configurations and operational effects in the second embodiment shown in FIGS. 8 and 9 are the same as those in the first embodiment shown in FIGS.

The illustrated embodiment is merely an example, and is not intended to limit the technical scope of the present invention.
For example, in the illustrated embodiment, the case where the tire is attached to the run-flat wheel is described, but the monitoring system and the monitoring of the present invention are also applicable to the case where the tire is attached to a normal wheel having no core on the rim. The method can be applied.
1 to 3 show that the touch sensor and the transmitter are configured as separate parts and are connected by connection (wire harness), but the sensors (touch sensor 5 and temperature sensor 6) are shown. ) And the transmitter may be integrated into a sensor unit. Moreover, you may comprise a sensor (touch sensor 5, temperature sensor 6) and a transmitter as an integrated circuit.
Further, in FIG. 9, the touch sensor measurement signal transmitter 16 and the temperature sensor measurement signal transmitter 17 are shown separately, but the touch sensor measurement signal transmitter 16 and the temperature sensor measurement signal transmitter 17 are integrated. You may comprise, or it may comprise so that any one may serve the other function.

The block diagram which shows 1st Embodiment of this invention applied to the truck. The block diagram explaining the detailed structure except a vehicle among tire monitoring systems. The block diagram which shows typically the structure required for the tire pressure monitoring in FIG. The block diagram which simplifies and shows the structure by the side of a chassis. The partial expanded sectional view which shows the state which has arrange | positioned the touch sensor and the temperature sensor to the core of a run flat wheel. The flowchart which shows the control of 1st Embodiment. The block diagram which shows the principal part of the modification of 1st Embodiment. The block diagram which shows schematic structure of 2nd Embodiment. The block diagram explaining the detailed structure except a vehicle among the tire monitoring systems in 2nd Embodiment. The conceptual diagram of the run flat wheel in a prior art. The partial expanded sectional view of the run flat wheel in a prior art. The partial expanded sectional view which shows the modification of the touch sensor attachment state shown in FIG. The partial expanded sectional view which shows the modification of the touch sensor attachment state shown in FIG. The partial expanded sectional view which shows another modification of the touch sensor attachment state shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cargo vehicle / vehicle 2 ... Driver's cab / cab 3 ... Chassis 4 ... Wheel 5 ... Touch sensor 6 ... Temperature sensor 7 ... Transmitter 8 ... Receiver DESCRIPTION OF SYMBOLS 9 ... Control apparatus 10 ... Warning apparatus 11 ... Battery 13 ... Key switch 16 ... Touch sensor measurement signal transmitter 17 ... Temperature sensor measurement signal transmitter 18 ... Radio wave / current Conversion device 19 ... Radio wave transmitter 22 ... Capacitor

Claims (2)

Touch that senses that the air pressure of the tire (45) has dropped on the core (44) of the rim (41) of the wheel (4) and the ground contact portion (45a) of the tire (45) has come into contact with the rim (41) side. A sensor (5, 5S), a temperature sensor (6) that measures the temperature of the internal space (45i) of the tire (45), a detection result of the touch sensor (5, 5S), and a detection result of the temperature sensor (6) Are transmitted to the chassis (3) side as radio wave signals (So1, So11), the battery (73) is provided on the chassis (3) side, and the wheel (4) A receiver (8) that receives radio signals (So1, So11) transmitted from the transmitter (7, 16, 17), and a tire (45) from the radio signals (So1, So11) received by the receiver (8). Grounding part (45a) on the rim (41) side In a tire monitoring system having a control device (9) configured to determine whether or not it is touched, the sensing unit (50) of the touch sensor (5, 5S) is an outer edge portion ( 44a), the control means (9) has received a signal from the touch sensor (5, 5S) indicating that the grounding part (45a) of the tire (45) has been contacted. (S1), if the signal is received, it is determined whether or not the speed signal of the speedometer (12) is equal to or higher than a predetermined speed (S2). If it is determined that the tire is rolling and a signal indicating that the touch sensor (5, 5S) is in contact continues for a predetermined time or more (S3), The grounding part (45a) of the tire (45) is connected to the core (44). (S4), a measurement signal from the temperature sensor (6) is received (S5), and it is determined whether or not the temperature inside the tire (45i) is equal to or higher than the threshold temperature (S6). If the temperature is equal to or higher than the threshold temperature, the tire monitoring system has a function of warning that the tire internal temperature has risen to a dangerous area. The tire monitoring system according to claim 1, wherein the temperature sensor (6) is provided in a space (44i) inside the core (44).

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