JP2008155795A - Tire internal pressure warning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire internal pressure monitoring system for detecting an abnormality of a tire in which reduction amount of internal pressure per unit time is small and of easily detecting an abnormality in internal pressure of the tire and informing a driver. <P>SOLUTION: A control part 15 stores a tire internal pressure value at normal temperature obtained from a sensor module 3 during stop of the engine and the date and time when the engine is stopped in a storage part 12. Based on a tire internal pressure value at normal temperature obtained from the sensor module 3 at start of the engine and the tire internal pressure value at normal temperature during stop of the engine stored in the storage part 12, the control part 15 determines a tire internal pressure reduction ratio from the date and time when the engine is stopped until the date and time when the engine is started. When the tire internal pressure reduction ratio exceeds a predetermined value, the control part 15 determines that the tire is abnormal. When the control part 15 determines that the tire is abnormal, an abnormality informing part 16 informs a driver of the abnormality. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tire internal pressure warning system for reporting a tire abnormality such as a tire puncture.

  In recent years, as a method of checking whether or not the air pressure (internal pressure) filled in a pneumatic tire for automobiles is normal, a sensor module for measuring a tire state quantity such as a tire internal pressure or a tire internal temperature is attached to the inside of the tire. The tire pressure monitoring system (Tire Pressure Monitoring) is configured to receive the measurement data transmitted from the sensor module by wireless communication by the receiving device on the vehicle body side and display the received data on the on-board display of the cab. System (hereinafter referred to as TPMS) has been proposed to be mounted on a vehicle (for example, see Patent Document 1). There is also a handy tire internal pressure reader using wireless communication.

Further, in Patent Document 2, the tire air pressure is converted to a standard temperature to detect an internal air pressure abnormality, and the amount of decrease in the tire air pressure measured by the air pressure sensor per unit time decreases beyond a predetermined threshold. A tire pressure detecting device is described which generates a warning signal when it is done.
JP-A-10-302187 JP 2002-225519 A

  The tire pressure monitoring system and handy tire internal pressure reader described above temporarily store the obtained tire internal pressure information on the driver's onboard display or handy reader side, and finally input it to the computer. Management, there is a problem that the system becomes large and expensive. In addition, there is no simple system for detecting and reporting abnormalities in tire internal pressure for users who manage personal vehicles.

  Further, in the tire air pressure detecting device described in Patent Document 2, a decrease amount per unit time (for example, 5 seconds, 10 seconds, 30 seconds, etc.) of the tire air pressure is obtained while the vehicle is running, and when the decrease amount is large, that is, , A warning signal is generated when a sudden pressure drop is detected, and there is a problem that a tire abnormality with a small decrease in air pressure per unit time, such as when tire air gradually leaks, cannot be detected. .

  The present invention has been made in view of such problems, and an object of the present invention is to detect a tire abnormality with a small amount of decrease in air pressure per unit time and to easily detect the internal pressure of the tire. It is intended to provide a tire internal pressure warning system that detects and reports an abnormality in the tire.

  In order to achieve the above object, a tire internal pressure alarm system according to the present invention includes a sensor module that is installed in each tire of a vehicle and detects the tire internal pressure and the tire internal temperature, and the tire internal pressure and the tire internal transmitted from the sensor module. Receiving means for receiving a signal including a temperature value; conversion means for converting the tire pressure value at the tire temperature received and acquired by the receiving means into a tire pressure value at a standard temperature; and the reception when the engine is stopped Storage means for storing the tire internal pressure value at the standard temperature obtained by conversion by the conversion means from the tire internal pressure value obtained from the sensor module obtained through the means and the engine stop date and time, and the reception means at the time of engine start. Converted by the conversion means from the tire internal pressure value obtained from the sensor module. The tire internal pressure value at the standard temperature and the tire internal pressure value at the standard temperature at the time of engine stop stored in the storage means are used to obtain a tire internal pressure decrease rate from the engine stop date and time to the engine start date and time. An abnormality determination unit that determines that an abnormality is present when the rate of decrease is greater than a predetermined value, and an abnormality notification unit that reports an abnormality when the abnormality determination unit determines that the abnormality is abnormal. .

  The tire internal pressure alarm system according to the present invention includes a sensor module that is mounted in each tire of a vehicle and detects a tire internal pressure and a tire internal temperature, a keyless entry device that transmits a door close signal or a door open signal, and the sensor. Receives signals including tire internal pressure and tire temperature values transmitted from the module, receives a door closing signal transmitted from the keyless entry device when the door is locked, and transmits from the keyless entry device when the door is unlocked A receiving means for receiving a door opening signal; a converting means for converting the tire internal pressure value at the tire temperature received and acquired by the receiving means into a tire internal pressure value at a standard temperature; and via the receiving means at the time of door locking. Calculated by the conversion means from the tire internal pressure value obtained from the sensor module Storage means for storing the tire internal pressure value at the standard temperature and the door locking date and time, and the standard temperature obtained by converting by the conversion means from the tire internal pressure value from the sensor module obtained through the receiving means at the time of door unlocking The tire internal pressure decrease rate from the door locking date to the door unlocking date is obtained from the tire internal pressure value at the standard temperature at the time of the door locking stored in the storage means, and the tire internal pressure decreasing rate is determined. An abnormality determination unit that determines that an abnormality is found when the value is larger than a predetermined value, and an abnormality notification unit that reports an abnormality when the abnormality determination unit determines that the abnormality is abnormal.

  Preferably, the abnormality reporting means reports an abnormality by lighting and blinking a hazard lamp at a timing different from a normal blinking timing, or a hazard lamp near a tire in which the tire internal pressure reduction rate is greater than a predetermined value It is preferable to report an abnormality by lighting and blinking only at a timing different from the normal blinking timing.

  Moreover, it is preferable that the abnormality reporting means reports the abnormality by lighting and blinking an alarm display section of the keyless entry device.

  Since the present invention measures the amount of decrease in tire internal pressure over a long period of time and determines an abnormality in the internal pressure of the tire, tires with a small amount of decrease in internal pressure per unit time such as when tire air gradually leaks are used. Abnormalities can be detected. Further, it is possible to easily detect an abnormality in the internal pressure of the tire.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a tire internal pressure warning system according to the first embodiment of the present invention. The tire internal pressure alarm system shown in FIG. 1 is installed in each tire 4 of the vehicle 6 to detect the internal pressure and internal temperature of the tire 4, and a signal including the detected tire internal pressure and tire internal temperature is sent to the vehicle body side. It comprises a sensor module 3 for transmission and a central control device 1 installed on the vehicle body side. The central control device 1 includes a transmission / reception unit (reception unit) 11 that receives signals including values of the tire internal pressure and the tire internal temperature transmitted wirelessly from the antenna of the sensor module 3, and the sensor module 3 acquired when the engine is stopped. The storage unit (storage unit) 12 stores the tire internal pressure value at the standard temperature obtained by conversion from the tire internal pressure value and the engine stop date and time, and the tire internal temperature received and acquired by the transmission / reception unit (reception unit) 11. Means for converting the tire internal pressure value into the tire internal pressure value at the standard temperature (conversion means), the tire internal pressure value at the standard temperature obtained by converting the tire internal pressure value from the sensor module 3 acquired at the time of starting the engine by the conversion means, The engine stop date based on the tire internal pressure value at the standard temperature when the engine is stopped, which is stored in the storage unit 12 The control unit 15 includes a means (abnormality determination means) for determining an abnormality when the tire internal pressure decrease rate from the engine start date to the engine start date and time is greater than a predetermined value. An abnormality reporting unit (abnormality reporting means) 16 for reporting an abnormality when it is determined to be an engine, and an engine start / stop mechanism unit 17 for outputting an engine start signal when the engine is started and outputting an engine stop signal when the engine is stopped. ing.

  FIG. 2 is a diagram showing the relationship between the internal pressure (air pressure) of the tire and the passage of time. As shown in the figure, the internal pressure of the tire decreases as a long time passes even in a tire having no abnormality. In addition, since the temperature of the air in a tire rises by driving | running | working, in order to ignore the air pressure change by this temperature change, in FIG. 2, the pressure at the time of converting into standard temperature is shown. The storage unit 12 stores in advance a tire internal pressure decrease rate that is a decrease amount of the tire internal pressure per unit time when there is no abnormality in the tire.

  As shown in the sectional view of the tire in FIG. 3, the sensor module 3 is attached to a wheel rim 23 integrally with a cylindrical tire valve 22 for injecting air into the tire. The sensor module 3 may be mounted by being baked on the inner surface of the tire so as not to be isolated or broken from the tire even if the running tire is deformed under load. It can also be held in the tire inner space by a separate means. When the sensor module 3 receives the tire internal pressure information return request signal from the transmission / reception unit 11, the sensor module 3 measures the tire internal pressure and outputs a signal including a sensor ID and a tire internal pressure value, which is an identification code unique to the sensor module, to the outside of the tire. Output.

Next, the operation of the first exemplary embodiment of the present invention will be described. When the driver stops the engine of the vehicle, the engine start / stop mechanism unit 17 transmits an engine stop signal to the control unit 15. When an engine stop signal is transmitted from the engine start / stop mechanism unit 17, the control unit 15 transmits a response request signal for in-tire information to the sensor module 3 via the transmission / reception unit 11. When the sensor module 3 receives a reply request signal for in-tire information, measures the tire internal pressure and the tire internal temperature, and transmits a signal including the sensor ID, the tire internal pressure, and the tire internal temperature to the transmission / reception unit 11. , the control unit 15 acquires the sensor ID and the tire inner pressure value and the tire internal temperature value via the transmitting and receiving unit 11, converts the tire pressure values in the acquired tire temperature inside the tire internal pressure value P ₁ at the standard temperature, in terms of the tire internal pressure value P ₁ for every tire with the engine stop time T ₁ in the standard temperature, that is, stored in the storage unit 12 for each sensor ID.

  When the driver starts the engine of the vehicle, the engine start / stop mechanism unit 17 transmits an engine start signal to the control unit 15. When an engine start signal is sent from the engine start / stop mechanism unit 17, the control unit 15 transmits a response request signal for in-tire information to the sensor module 3 via the transmission / reception unit 11. When the sensor module 3 receives a reply request signal for in-tire information, measures the tire internal pressure and the tire internal temperature, and transmits a signal including the sensor ID, the tire internal pressure, and the tire internal temperature to the transmission / reception unit 11, The control unit 15 acquires a tire internal pressure value and a tire internal temperature value for each tire, that is, for each sensor ID, via the transmission / reception unit 11.

For each tire (sensor ID), the control unit 15 converts the tire internal pressure value acquired at engine startup into the tire internal pressure value P ₂ at the standard temperature, and the converted tire internal pressure value P ₂ is stored in the storage unit 12. An internal pressure difference ΔP (ΔP = P ₂ −P ₁ ) with respect to the tire internal pressure value P ₁ when the engine is stopped is obtained, and this tire internal pressure difference ΔP is determined as a time difference from the engine stop date / time T ₁ to the engine start date / time T _2. By dividing by ΔT (ΔT = T ₂ −T ₁ ), a tire internal pressure reduction rate (ΔV / ΔT) is obtained, and this value is stored in advance in the storage unit 12 and the tire internal pressure when there is no abnormality in the tire. It is determined that there is an abnormality in the tire when it is greater than the reduction rate.

  When the control unit 15 determines that there is an abnormality in the tire, the abnormality reporting unit 16 lights and blinks the hazard lamp 5 at a timing different from the normal blinking timing, and further lights and blinks the on-board indicator on the cab. By displaying, the driver of the vehicle and the driver of the following vehicle are notified of the abnormality of the tire.

  As described above, according to the present invention, when the engine is started, the tire internal pressure abnormality is measured by measuring the amount of decrease in the tire internal pressure over a long period from the engine stop date to the engine start date. It is possible to detect an abnormality of the tire with a small amount of decrease in internal pressure per unit time, such as when the air leaks.

  Note that the relationship between the sensor ID and the tire mounting position is stored in the storage unit 12 in advance, and if the control unit 15 determines that there is an abnormality in the tire, the abnormality notification unit 16 determines whether the tire has an abnormality. The tire mounting position may be determined from the sensor ID, and the abnormality may be reported by turning on and blinking only the hazard lamp in the vicinity of the tire having the abnormality at a timing different from the normal blinking timing. By turning on and blinking only the hazard lamps in the vicinity of abnormal tires, the driver can know which tire is abnormal.

  Next, a second embodiment of the present invention will be described. FIG. 4 is a block diagram of a tire internal pressure warning system according to the second embodiment of the present invention. The tire internal pressure warning system shown in FIG. 4 is installed in each tire 4 of the vehicle 6 to detect the internal pressure and internal temperature of the tire 4 and to send a signal including the detected tire internal pressure and tire internal temperature to the vehicle body side. It comprises a sensor module 3 for transmission, a central control device 1 installed on the vehicle body side, and a keyless entry device 2.

  As shown in FIG. 5, the keyless entry device 2 includes a battery power source 31, a push button 32 for locking and unlocking the door of the vehicle 6, a control unit 33, and a door by input from the push button 32. And a transmitter 34 that wirelessly transmits a close signal or a door open signal.

  The central control device 1 includes a signal including values of tire internal pressure and tire temperature wirelessly transmitted from the antenna of the sensor module 3, a door closing signal wirelessly transmitted from the keyless entry device 2 when the door is locked, A standard obtained by converting from a tire internal pressure value obtained from a sensor module 3 acquired at the time of door locking and a transmission / reception unit (reception means) 11 that receives a door opening signal transmitted wirelessly from the keyless entry device 2 at the time of door unlocking. The tire internal pressure value at the standard temperature is set to the tire internal pressure value at the tire temperature received by the storage unit (storage unit) 12 that stores the tire internal pressure value at the temperature and the door locking date and time, and the transmission / reception unit (reception unit) 11. The conversion means (converting means) and the tire internal pressure value obtained from the sensor module 3 obtained at the time of door unlocking are converted by the converting means. The tire pressure reduction rate from the door locking date and time to the door unlocking date and time is obtained from the tire internal pressure value at the standard temperature and the tire internal pressure value at the standard temperature at the time of door locking stored in the storage unit 12, and the tire internal pressure is calculated. A control unit 15 including means (abnormality determination means) for determining that the tire is abnormal when the reduction rate is greater than a predetermined value, and reporting an abnormality when the control unit 15 determines that the tire is abnormal An abnormality reporting unit (abnormality reporting means) 16 is provided.

  Similar to the first embodiment, the storage unit 12 stores in advance a tire internal pressure decrease rate that is a decrease amount of the tire internal pressure per unit time when there is no abnormality in the tire. The sensor module 3 has the same configuration as that of the first embodiment.

Next, the operation of the second exemplary embodiment of the present invention will be described. When the driver pushes the push button 32 of the keyless entry device 2 to lock the door and transmits a door closing signal from the keyless entry device 2 to the transmission / reception unit 11, the transmission / reception unit 11 sends the received door closing signal to the control unit 15. Output. When a door closing signal is sent from the transmission / reception unit 11, the control unit 15 transmits a response request signal for in-tire information to the sensor module 3 via the transmission / reception unit 11. When the sensor module 3 receives a reply request signal for in-tire information, measures the tire internal pressure and the tire internal temperature, and transmits a signal including the sensor ID, the tire internal pressure, and the tire internal temperature to the transmission / reception unit 11, control unit 15 acquires the sensor ID and the tire inner pressure value and the tire internal temperature value via the transmitting and receiving unit 11, it converts the tire pressure values in the acquired tire temperature inside the tire internal pressure value P ₁ at standard temperature and converted the tire internal pressure value P ₁ for every tire with door locking time T ₁ at standard temperature, that is, stored in the storage unit 12 for each sensor ID.

  When the driver pushes the push button 32 of the keyless entry device 2 to unlock the door and transmits a door opening signal from the keyless entry device 2 to the transmission / reception unit 11, the transmission / reception unit 11 transmits the received door opening signal to the control unit 15. Output to. When a door opening signal is sent from the transmission / reception unit 11, the control unit 15 transmits a response request signal for in-tire information to the sensor module 3 via the transmission / reception unit 11. When the sensor module 3 receives a reply request signal for in-tire information, measures the tire internal pressure and the tire internal temperature, and transmits a signal including the sensor ID, the tire internal pressure, and the tire internal temperature to the transmission / reception unit 11, The control unit 15 acquires a tire internal pressure value and a tire internal temperature value for each tire, that is, for each sensor ID, via the transmission / reception unit 11.

For each tire (sensor ID), the control unit 15 converts the tire internal pressure value acquired at the time of door unlocking into the tire internal pressure value P ₂ at the standard temperature, and is stored in the converted tire internal pressure value P ₂ and the storage unit 12. An internal pressure difference ΔP (ΔP = P ₂ −P ₁ ) with respect to the tire internal pressure value P ₁ when the door is locked is obtained, and this tire internal pressure difference ΔP is calculated from the door locking date / time T ₁ to the door unlocking date / time T _2. By dividing by the time difference ΔT (ΔT = T ₂ −T ₁ ), the tire internal pressure reduction rate (ΔV / ΔT) is obtained, and this value is stored in advance in the storage unit 12 when there is no abnormality in the tire. It is determined that there is an abnormality in the tire when the tire internal pressure reduction rate is greater.

  When the control unit 15 determines that there is an abnormality in the tire, the abnormality notification unit 16 notifies the vehicle driver of the tire abnormality by lighting and blinking the hazard lamp 5 at a timing different from the normal blinking timing. To do. In the above-described embodiment, the standard temperature conversion is performed by the control unit 15 provided in the central controller. However, the present invention is not limited to this, and the standard temperature conversion is performed in advance on the sensor module side and the pressure is transmitted. You may make it do.

  As described above, according to the present invention, when the door is unlocked, the amount of decrease in the tire internal pressure over a long period of time from the door locking date to the door unlocking date is measured to determine abnormality of the tire internal pressure. Thus, it is possible to detect a tire abnormality with a small amount of decrease in internal pressure per unit time, such as when the tire air leaks.

  Note that the relationship between the sensor ID and the tire mounting position is stored in the storage unit 12 in advance, and if the control unit 15 determines that there is an abnormality in the tire, the abnormality notification unit 16 determines whether the tire has an abnormality. The tire mounting position may be determined from the sensor ID, and the abnormality may be reported by turning on and blinking only the hazard lamp in the vicinity of the tire having the abnormality at a timing different from the normal blinking timing. By turning on and blinking only the hazard lamps in the vicinity of abnormal tires, the driver can know which tire is abnormal.

  FIG. 6 is a block diagram showing another example of the keyless entry device. The keyless entry device 7 shown in FIG. 7 includes a power source 31 composed of a battery, a push button 32 for opening and closing the door of the vehicle 6, a control unit 33, a transmission / reception unit 35, and an alarm display unit 36. When the control unit 15 of the central control device 1 determines that there is an abnormality in the tire, an error notification signal is transmitted from the transmission / reception unit 11 to the keyless entry device 7, and the alarm display unit 36 of the keyless entry device 7 is turned on and blinked. The driver may be informed of the tire abnormality.

1 is a block diagram of a tire internal pressure warning system according to a first embodiment of the present invention. It is a figure which shows the relationship between the internal pressure (air pressure) of a tire, and progress of time. It is sectional drawing which shows the state which attached the sensor module to the tire. It is a block diagram of the tire internal pressure warning system which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows an example of a keyless entry apparatus. It is a block diagram which shows the other example of a keyless entry apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Central control apparatus 2,7 Keyless entry apparatus 3 Sensor module 4 Tire 5 Hazard lamp 6 Vehicle 11,35 Transmission / reception part 12 Storage part 15,33 Control part 16 Abnormality notification part 17 Engine start / stop mechanism part 22 Tire valve 23 Wheel rim 31 Power supply 32 Push button 34 Transmitter 36 Alarm display

Claims (5)

A sensor module that is mounted in each tire of the vehicle and detects a tire pressure and a tire temperature;
Receiving means for receiving signals including values of tire internal pressure and tire internal temperature transmitted from the sensor module;
Conversion means for converting the tire internal pressure value at the tire internal temperature received and acquired by the receiving means into a tire internal pressure value at a standard temperature;
Storage means for storing a tire internal pressure value at a standard temperature calculated by the conversion means from a tire internal pressure value obtained from the sensor module acquired through the receiving means when the engine is stopped and an engine stop date and time;
The tire internal pressure value at the standard temperature obtained by conversion by the conversion means from the tire internal pressure value from the sensor module acquired through the receiving means at the time of engine start, and the engine stop time stored in the storage means An abnormality determination means for determining a tire internal pressure reduction rate from the engine stop date and time to the engine start date and time based on the tire internal pressure value at the standard temperature, and determining that the tire internal pressure decrease rate is abnormal when the tire internal pressure decrease rate is greater than a predetermined value;
An abnormality reporting means for reporting an abnormality when the abnormality determining means is determined to be abnormal;
A tire internal pressure warning system comprising: A sensor module that is mounted in each tire of the vehicle and detects a tire pressure and a tire temperature;
A keyless entry device that transmits a door close signal or a door open signal; and
Receives a signal including the values of tire internal pressure and tire temperature transmitted from the sensor module, receives a door closing signal transmitted from the keyless entry device when the door is locked, and transmits from the keyless entry device when the door is unlocked Receiving means for receiving a door open signal,
Conversion means for converting the tire internal pressure value at the tire internal temperature received and acquired by the receiving means into a tire internal pressure value at a standard temperature;
Storage means for storing a tire internal pressure value at a standard temperature calculated by the conversion means from a tire internal pressure value obtained from the sensor module obtained through the receiving means at the time of door locking, and a door locking date and time;
The tire internal pressure value at the standard temperature obtained by converting the tire internal pressure value from the sensor module obtained through the receiving means at the time of door unlocking by the conversion means, and the door locking time stored in the storage means An abnormality determination means for determining a tire internal pressure reduction rate from a door locking date to a door unlocking date based on a tire internal pressure value at a standard temperature, and determining an abnormality when the tire internal pressure reduction rate is greater than a predetermined value; ,
An abnormality reporting means for reporting an abnormality when the abnormality determining means is determined to be abnormal;
A tire internal pressure warning system comprising:   3. The tire internal pressure alarm system according to claim 1, wherein the abnormality reporting unit reports an abnormality by turning on and blinking a hazard lamp at a timing different from a normal blinking timing.   The abnormality reporting means reports an abnormality by lighting and blinking only a hazard lamp in the vicinity of a tire having a tire internal pressure reduction rate larger than a predetermined value at a timing different from a normal blinking timing. Item 3. The tire internal pressure alarm system according to Item 1 or 2.   The tire internal pressure alarm system according to claim 2, wherein the abnormality notification means reports an abnormality by lighting and blinking an alarm display section of the keyless entry device.

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