Tire air pressure monitoring system, tire air pressure sensor unit and method of monitoring-controlling tire air pressure

Abstract

A tire air pressure monitoring system includes: a sensor unit mounted to a tire and including: an air pressure sensor for outputting a tire air pressure, and a transmitter, a receiver for receiving a radio wave from the sensor unit; a tire air pressure monitoring controller for warning a vehicular occupant of a tire air pressure decrease when the tire air pressure is less than or equal to a warning threshold. A puncture sensor for sensing a puncture of the tire, and a puncture repairing agent use sensor for sensing whether or not the puncture is repaired by using a puncture repairing agent after the puncture is sensed. When the puncture repairing agent use sensor senses that the punctured tire is repaired using the puncture repairing agent, the tire air pressure monitoring controller continues the warning even though the tire air pressure from the air pressure sensor is normal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an entire perspective view of a vehicle to which a tire air pressure monitoring system is applied, according to first to fifth embodiments of the present invention.

FIG. 2 is a control block diagram of the tire air pressure monitoring system, according to the first to fifth embodiments of the present invention.

FIG. 3 is a flow chart of tire air pressure monitoring control operations implemented by a control ECU, according to the first embodiment of the present invention.

FIG. 4 sets forth issues brought about when the puncture is repaired by using a puncture repairing agent, according to a background art, where

FIG. 4A shows an ordinary state,

FIG. 4B shows that the puncture has occurred and the puncture repairing agent is used, and

FIG. 4C shows a state where the tire air pressure is decreased.

FIG. 5 shows air pressure characteristics of each tire, where

• • [I] denotes burst or puncture occurrence, [II] denotes an ordinary tire air pressure decrease, [III] denotes a puncture sensing threshold Ts, [IV] denotes tire air pressure decrease after puncture occurrence, and M denotes tire air pressure decrease after burst occurrence.

FIG. 6 shows tire air pressure characteristics including: i) an actual tire air pressure obtained when the puncture is repaired by using the puncture repairing agent, ii) the puncture sensing threshold Ts [II], and iii) a repairing agent use sensing threshold Traus [VI].

FIG. 7 shows tire air pressure characteristics including: i) an actual tire air pressure obtained when the user resets the tire air pressure (which was set high for high speed way traveling) to a placard pressure (tire setting pressure) and ii) the puncture sensing threshold Ts.

FIG. 8 is a flow chart of the tire air pressure monitoring control operations implemented by the control ECU, according to the second embodiment of the present invention.

FIG. 9 shows acceleration characteristics of tires wherein,

FIG. 9A shows a state where the user repairs the puncture by using the puncture repairing agent with the punctured tire mounted to the vehicle, and

FIG. 9B shows a state where the user repairs the puncture by using rubber, putty and the like with the punctured tire dismounted from the vehicle.

FIG. 10 is a flow chart of the tire air pressure monitoring control operations implemented by the control ECU, according to the third embodiment of the present invention.

FIG. 11 shows variation characteristics of the air pressure sensor values wherein,

FIG. 11A shows a first pattern in which the punctured hole is blocked with the puncture repairing agent, and

FIG. 11B shows a second pattern in which the punctured hole is blocked with rubber, putty and the like instead of the puncture repairing agent.

FIG. 12 is a flow chart of the tire air pressure monitoring control operations implemented by the control ECU, according to the fourth embodiment of the present invention.

FIG. 13 is a flow chart of the tire air pressure monitoring control operations implemented by the control ECU, according to the fifth embodiment of the present invention.

Claims

1. A tire air pressure monitoring system, comprising: 1) a sensor unit configured to be mounted to each tire of a vehicle and including: i) an air pressure sensor configured to output a tire air pressure, andii) a transmitter configured to transmit a radio wave;2) a receiver configured to receive the radio wave transmitted from the sensor unit;3) a tire air pressure monitoring controller configured to warn a vehicular occupant of a tire air pressure decrease when the tire air pressure is less than or equal to a warning threshold,the tire air pressure monitoring system further comprising:4) a puncture sensor configured to sense a puncture of the tire, and 5) a puncture repairing agent use sensor configured to sense whether or not the puncture is repaired by using a puncture repairing agent after the puncture is sensed,whereinwhen the puncture repairing agent use sensor senses that the punctured tire is repaired by using the puncture repairing agent, the tire air pressure monitoring controller continues the warning even though the tire air pressure from the air pressure sensor is normal.

2. The tire air pressure monitoring system as claimed in claim 1, wherein the puncture repairing agent use sensor senses, in the following state, that the puncture is repaired by using the puncture repairing agent:a first state where i) the tire air pressure recovers to more than or equal to the warning threshold after the puncture is sensed, andii) a value showing a decrease rate of the tire air pressure after the recovery of the tire air pressure is less than a repairing agent use sensing threshold which is smaller than a value showing the decrease rate attributable to the tire air pressure decrease caused at an air pressure adjustment only without using the puncture repairing agent.

3. The tire air pressure monitoring system as claimed in claim 1, wherein the puncture sensor senses, in the following state, that the tire is punctured:a second state where i) the value showing the decrease rate of the tire air pressure shows a decrease more than or equal to a puncture sensing threshold, andii) the tire air pressure shows less than or equal to a puncture warning threshold.

4. The tire air pressure monitoring system as claimed in claim 1, wherein with the tire air pressure decreased, the sensor unit transmits at least once a piece of tire air pressure information from the air pressure sensor to the tire air pressure monitoring controller,the tire air pressure monitoring controller includes: i) the puncture sensor configured to sense the puncture based on the tire air pressure information transmitted from the sensor unit, andii) the puncture repairing agent use sensor configured to sense the puncture repairing agent use.

5. The tire air pressure monitoring system as claimed in claim 4, wherein when the value showing the decrease rate of the tire air pressure is larger, the sensor unit shortens a frequency of transmitting to the tire air pressure monitoring controller the tire air pressure information from the air pressure sensor.

6. The tire air pressure monitoring system as claimed in claim 1, wherein the puncture repairing agent use sensor, in the following state, senses that the puncture is repaired without using the puncture repairing agent:a third state where i) the tire air pressure recovers to more than or equal to the warning threshold after the puncture is sensed, andii) the tire is dismounted in a stop of the vehicle after the recovery of the tire air pressure.

7. The tire air pressure monitoring system as claimed in claim 6, wherein monitoring an acceleration signal from the air pressure sensor mounted to the each tire, the puncture repairing agent use sensor senses a vibration caused to the each tire, andwhen the acceleration more than or equal to an acceleration threshold is caused only to a puncture-occurred wheel, the puncture repairing agent use sensor senses that the tire is dismounted.

8. The tire air pressure monitoring system as claimed in claim 1, wherein the puncture repairing agent use sensor, in the following state, senses that the puncture is repaired by using the puncture repairing agent:a fourth state where the tire air pressure recovers to more than or equal to the warning threshold after the puncture is sensed, anda variation of the tire air pressure of the puncture-occurred wheel is different from a variation of the tire air pressure of a wheel other than the puncture-occurred wheel, when the vehicle is traveling after the recovery of the tire air pressure.

9. The tire air pressure monitoring system as claimed in claim 8, wherein the puncture repairing agent use sensor senses, in the following state, that the puncture is repaired by using the puncture repairing agent:a fifth state where a deviation between the following values is more than or equal to the repairing agent use sensing threshold which is determined in view of I) an air pressure change attributable to a temperature increase and II) an air pressure fluctuation with a wheel rotation:i) a first value showing a slope of a tire air pressure characteristic approximated by a linear function of the variation of the tire air pressure of the puncture-occurred wheel, andii) a second value showing a slope of a tire air pressure characteristic approximated by a linear function of the variation of the tire air pressure of the wheel other than the puncture-occurred wheel.

10. The tire air pressure monitoring system as claimed in claim 1, wherein the sensor unit includes the puncture repairing agent use sensor configured to sense the puncture repairing agent use based on the tire air pressure measured by the air pressure sensor.

11. The tire air pressure monitoring system as claimed in claim 10, wherein when the puncture repairing agent use sensor senses the puncture repairing agent use, the sensor unit stops transmitting a piece of tire air pressure information or transmits a piece of repairing agent use information, andwhen the tire air pressure recovers to more than or equal to the warning threshold after the puncture is sensed, the tire air pressure monitoring controller is configured to continue the warning, in one of the following states:i) a sixth state where the transmission of the tire air pressure information from the sensor unit is stopped, andii) a seventh state where the repairing agent use information is received.

12. The tire air pressure monitoring system as claimed in claim 1, wherein based on a piece of tire temperature information, the puncture sensor sets the puncture sensing threshold showing the decrease rate of the tire air pressure for sensing the puncture.

13. The tire air pressure monitoring system as claimed in claim 1, wherein based on a piece of tire temperature information, the puncture repairing agent use sensor sets the repairing agent use sensing threshold showing the decrease rate of the tire air pressure for sensing the puncture repairing agent use.

14. A method of monitoring-controlling a tire air pressure, comprising: 1) sensing the tire air pressure, including the following sub-operations: i) outputting the tire air pressure, andii) transmitting a radio wave;2) a receiving the radio wave transmitted from the transmitting;3) monitoring-controlling to warn a vehicular occupant of a tire air pressure decrease when the tire air pressure is less than or equal to a warning threshold,the monitoring-controlling further comprising:4) puncture sensing for sensing a puncture of a tire, and5) puncture repairing agent use sensing for sensing whether or not the puncture is repaired by using a puncture repairing agent after the puncture sensing,whereinwhen the puncture repairing agent use sensing senses that the punctured tire is repaired by using the puncture repairing agent, the monitoring-controlling continues the warning even though the tire air pressure from the outputting is normal.

15. A tire air pressure monitoring system, comprising: 1) sensing means mounted to each tire of a vehicle and including: i) air pressure sensing means for outputting a tire air pressure, andii) transmitting means for transmitting a radio wave;2) receiving means for receiving the radio wave transmitted from the sensing means;3) monitoring-controlling means for warning a vehicular occupant of a tire air pressure decrease when the tire air pressure is less than or equal to a warning threshold,the tire air pressure monitoring system further comprising:4) puncture sensing means for sensing a puncture of the tire, and5) puncture repairing agent use sensing means for sensing whether or not the puncture is repaired by using a puncture repairing agent after the puncture is sensed,whereinwhen the puncture repairing agent use sensing means senses that the punctured tire is repaired by using the puncture repairing agent, the monitoring-controlling means continues the warning even though the tire air pressure from the air pressure sensing means is normal.

16. A tire air pressure monitoring system, comprising: 1) a sensor unit configured to be mounted to each tire of a vehicle and including: i) an air pressure sensor configured to output a tire air pressure, andii) a transmitter configured to transmit a radio wave; and2) a receiver configured to receive the radio wave transmitted from the sensor unit;whereinthe tire air pressure monitoring system is configured to warn a vehicular occupant of a tire air pressure decrease when the tire air pressure is less than or equal to a warning threshold, andin a case that a puncture is sensed to occur to the tire: when the punctured tire is sensed to be repaired by using a puncture repairing agent, the tire air pressure monitoring system continues the warning even though the tire air pressure from the air pressure sensor is normal.

17. A tire air pressure sensor unit configured to be mounted to each tire of a vehicle and including an air pressure sensor and a transmitter, the tire air pressure sensor unit comprising: 1) a puncture sensor configured to sense a puncture of the tire, and2) a puncture repairing agent use sensor configured to sense whether or not the puncture is repaired by using a puncture repairing agent after the puncture is sensed,whereinwhen the punctured tire is sensed to be repaired by using the puncture repairing agent, the tire air pressure sensor unit stops transmitting a piece of tire air pressure information or transmits a piece of repairing agent use information.