JP2003341317A - Tire air pressure-monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire air pressure-monitoring device by which tire air pressure can easily be checked from the outside of a vehicle when a user performs a starting check before getting on the vehicle. <P>SOLUTION: This tie air pressure-monitoring device is equipped with a monitoring unit 20 which determines whether the air pressure of tire is normal or not by comparing the output of a pressure sensor which generates an output indicating air pressures of four tires fitted on the vehicle with a specified value. In the tire air pressure-monitoring device, an indicator (notifying unit 50b) which notifies the user of a determination result is provided on a remote keyless entry (portable terminal unit) 50 which is carried by the user outside of the vehicle, and thus, the user is notified of the determination result. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire pressure monitoring device.

[0002]

2. Description of the Related Art For a user of an automobile (vehicle), the amount of engine oil and the amount of radiator cooling fluid can be easily visually checked from the outside at the time of start-up inspection. Is difficult to confirm from the outside.

From that intention, in Japanese Patent Publication No. 43-17766, a tire of a vehicle is provided with a pressure-responsive electric switch,
A sensor unit including a small oscillator including a transmission antenna is attached, and when the tire air pressure drops below a predetermined value, the oscillator is activated to output an output, and a monitoring unit including a reception antenna is provided near the driver's seat. Tire pressure monitoring devices have been proposed which are adapted to receive output.

In addition to the above, as a method for detecting tire air pressure, a method for directly detecting tire air pressure using a pressure sensor as proposed in JP-A-2000-142043, and JP-A-6-92114. It is well known to estimate from the output of a wheel speed sensor for ABS (Antilock Brake System) as proposed in the publication.

[0005]

As described above, although it is possible to confirm a decrease in tire air pressure during traveling by the above-mentioned conventional technique, the user can easily check the tire air pressure from the outside of the vehicle at the start-up inspection before boarding. It was still difficult to confirm.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tire air pressure monitoring device which solves the above-mentioned inconvenience and allows the user to easily check the tire air pressure from the outside of the vehicle at the start-up inspection before boarding.

[0007]

To achieve the above object, according to the present invention, in claim 1, the output of a sensor for producing an output indicating the air pressure of a plurality of tires mounted on a vehicle is set to a predetermined value. In a tire pressure monitoring device including a monitoring unit that determines whether or not the tire pressure is appropriate, the portable terminal device carried by the user outside the vehicle notifies the user of the result of the determination. It was constructed so as to provide a notification unit.

Since the portable terminal device carried by the user outside the vehicle is provided with an informing unit for informing the user of the result of determination as to whether or not the tire pressure is proper, the user can start the work before boarding the vehicle. Tire pressure can be easily checked from the outside of the vehicle during inspections.

In the above description, "the output of a sensor that produces an output indicating the air pressure of a plurality of tires mounted on a vehicle is compared with a predetermined value to determine whether or not the air pressure of the tire is appropriate."
May be a method of directly detecting the tire air pressure using a pressure sensor as proposed in the above-mentioned Japanese Patent Laid-Open No. 2000-142043, and comparing the detected value with a predetermined value to make a determination, or As proposed in the above-mentioned Japanese Patent Laid-Open No. 6-92114, ABS (Antilock Brake System)
A method of determining the output of the wheel speed sensor for m) by comparing it with a predetermined value may be used. Further, the notifying unit may notify the user visually or audibly, or both.

According to another aspect of the present invention, there is provided a first transmission antenna for transmitting the output of the pressure sensor, which is arranged on each of the plurality of tires mounted on the vehicle, and which produces an output indicating the tire pressure. And a sensor unit that includes at least the following, and is mounted on the vehicle, receives an output transmitted from the sensor unit via a first receiving antenna, and compares the output with a predetermined value to determine whether the tire pressure is appropriate. In the tire pressure monitoring device including a monitoring unit that displays the determination result on the first notification unit, a second transmitting antenna arranged in the monitoring unit and a portable device carried by the user outside the vehicle. A terminal device, a second receiving antenna arranged in the mobile terminal device, and a second notification unit provided in the mobile terminal device are provided, and
The monitoring unit is configured to display the determination result on the second notification unit via the second transmitting antenna and the second receiving antenna according to an instruction from the user.

The monitoring unit displays the result of determining whether the tire pressure is proper via the second transmitting antenna and the second receiving antenna according to the user's instruction on the second notification unit provided in the portable terminal device. Since it is configured as described above, the user can easily check the tire pressure from the outside of the vehicle at the start-up inspection before getting on the vehicle, as in the first aspect. The first notifying unit and the second notifying unit may notify the user visually or audibly, or both of them. Is the same as.

According to another aspect of the present invention, the portable terminal is a remote keyless entry, a portable telephone and a PH.
Configured to be one of the S phones.

Since the mobile terminal is configured to be one of a remote keyless entry, a mobile phone and a PHS phone, the user can easily and quickly check the tire pressure from the outside of the vehicle at the start-up inspection before boarding. Can be confirmed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory view showing an overall tire air pressure monitoring device according to one embodiment.

Reference numeral 10 denotes the tire pressure monitoring device, and the tire pressure monitoring device 10 is provided at each of four (plural) tires generally designated by reference numeral 14 mounted on the vehicle 12 and designated by reference numeral 16. Four sensor units, which are collectively referred to, and one monitoring unit 20, which is mounted at an appropriate position inside the vehicle 12, are provided. The four tires 14 and the sensor units corresponding thereto are specifically, as shown, the front right FR 14FR or 16FR, the rear right RR 14RR or 16RR, and the front left FL 14.
FL or 16FL and the rear left RL are indicated by 14RL or 16RL.

FIG. 2 is an explanatory sectional view showing the structure of the sensor unit 16.

As shown in the figure, the sensor unit 16 is integrally formed with a valve 14b for injecting air, which is mounted on a metal wheel disc (rim) 14a. A grommet (bush) 14b1 is inserted between the wheel disc 14a and the valve 14b, and the stem 1 of the valve 14b is
Flange portion 14b3 formed so as to project to the outer periphery of 4b2
By sandwiching the grommet 14b1 with the nut 14b4 (and the washer 14b5), the valve 14b is fixed at the illustrated position. The valve 14b is enlarged on the inner side of the wheel disc 14a, and the main body 16a of the sensor unit 16 is connected thereto. Incidentally, reference numeral 14b
6 is a cap, and 14b7 is a valve core for air filling.

FIG. 3 shows the main body 16a of the sensor unit 16.
3 is a block diagram showing in detail the configuration of FIG.

The body 16a of the sensor unit 16 is a CP
U22 and a pressure sensor 24 that produces an output indicating the air pressure inside the wheel disc 14a, that is, the tire air pressure.
And a temperature sensor 26 that produces an output indicating the temperature of that part.
Equipped with. The outputs of the sensors 24 and 26 are converted into digital values via an A / D conversion circuit (not shown), and the CPU 2
Entered in 2. The CPU 22 and the pressure sensor 24
Components such as the above are integrally mounted on one circuit board 28 and integrated into one chip.

A power source (lithium battery, battery power source) 30 is arranged in the main body 16a and functions as an operating power source for the CPU 22. Further, the main body 16a is provided with a transmitting antenna 32 and a receiving antenna 34, and the pressure sensor 24
And the output of the temperature sensor 26 is transmitted to the monitoring unit 20, while the transmission from the monitoring unit 20 is received.

Although not shown, the power source 30 and the CPU 22
A voltage sensor is provided at an appropriate position of the power supply circuit between
It outputs a signal according to the output voltage of the power supply 30. The output of the voltage sensor is also A / D converted and input to the CPU 22.

Returning to the description of FIG. 1, the monitoring unit 20.
Is a main body 20b (not shown in FIG. 1) housed in a housing 20a at an appropriate position in the vehicle compartment, and four receiving antennas collectively denoted by reference numeral 40, arranged near each of the tires 14. , And four transmission antennas collectively referred to by reference numeral 42. That is, the monitoring unit 20 includes transmitting antennas 40FR to 40RL and receiving antennas 42FR to 42RL arranged corresponding to the tires 14FR to 14RL. The receiving antenna 40 and the transmitting antenna 42 are connected to the main body 20b in the housing 20a via a coaxial cable 44.

Further, the monitoring unit 20 includes an indicator (first notification unit) 46 arranged on the dashboard of the driver's seat of the vehicle 12. Main body 20b in housing 20a of indicator 46 and monitoring unit 20
Are connected via a harness 48.

Reference numeral 50 designates a portable terminal device carried by the illustrated user outside the vehicle 12, specifically one of a remote keyless entry, a portable telephone device and a PHS telephone device, more specifically, 1 illustrates a remote keyless entry that incorporates a transmit antenna for transmitting lock and unlock signals for the door of vehicle 12. The mobile terminal is not limited to the above as long as it can be carried by the user outside the vehicle 12.

FIG. 4 is an explanatory block diagram showing in detail the configuration of the main body 20b of the monitoring unit 20 and the like.

As shown, the body 20 of the monitoring unit 20.
b includes a CPU 52. Similarly to the main body 16a of the sensor unit 16, the CPU 52 is also mounted on a single circuit board 54 and integrated into a single chip. The CPU 52 receives the data from the sensor unit 14 via the receiving antenna 40 described above, and also transmits the data via the transmitting antenna 42 as described later.

The indicator 46 includes first and second warning lights 46a and 46b and five display panels 46c and 46.
d, 46e, 46f, 46g. The indicator 46 is connected to the main body 20b, more specifically to the CPU 52 thereof, as described above.

FIG. 5 is an explanatory block diagram functionally showing the operation of the monitoring unit 20, more precisely, the CPU 52 of the main body 20b.

The CPU 52 uses the four tires 14 transmitted from the sensor unit 16 via the transmitting antenna 32.
Is inputted via the receiving antenna 40, and the air pressure comparison block 52a compares the input value with the first predetermined value. As the first predetermined value, the recommended value (Re
commended Cold Pressure. A value obtained when the vehicle 12 is left unattended and the tires 14 are completely cooled, and a value obtained by multiplying a value preset by the vehicle type) by 1.3 is used.

The CPU 52 has an air pressure comparison block 52a.
When it is determined that the input value for one or more of the four tires is equal to or more than the first predetermined value, it is determined that the tire has excess air pressure, and a lighting instruction signal (notification instruction signal) is output to the indicator 46. The first warning lamp 46a is turned on, and a transmission cycle switching signal (described later) is output to the sensor unit 16 via the antennas 42 and 34.

When the CPU 52 outputs a lighting instruction signal to turn on the first warning lamp 46a, the corresponding one of the four tire partial views of the vehicle figure shown in the panel 46c is displayed. Although the indicator 46 for visually notifying is used as the notifying means, a speaker or buzzer for displaying by voice may be used, or both of them may be used.

The CPU 52 has an air pressure comparison block 52a.
When it is determined that the input value (detected tire air pressure) is less than the first predetermined value, the process proceeds to the alarm determination block 52b, where the input value is compared with the second predetermined value. A value obtained by multiplying the recommended value by 0.8 is used as the second predetermined value.

When the alarm determination block 52b determines that the input value is less than the second predetermined value, the CPU 52 similarly outputs a lighting instruction signal to turn on the first warning lamp 46a, and the antennas 42 and 34. Through the sensor unit 1
A transmission cycle switching signal is output to 6.

On the other hand, when the input value is determined to be equal to or greater than the second predetermined value, the CPU 52 outputs the turn-off instruction signal to output the first turn-off instruction signal.
The warning light 46a is turned off. This is the same when the input value is determined to be less than the first predetermined value in the air pressure comparison block 52a.

Further, the CPU 52 uses the sensor unit 1
6, the temperature in the wheel disk 14a for the four tires 14, that is, the output of the temperature sensor 26 indicating the tire temperature, which is transmitted from the antenna 6 through the antennas 32 and 40, is input, and the input values are input in the temperature comparison block 52c. Compare with a predetermined temperature (for example, 80 ° C.).

The CPU 52 outputs a lighting instruction signal to turn on the first warning lamp 46a when the temperature comparison block 52c determines that the input value for one or more of the four tires is equal to or higher than a predetermined temperature. At the same time, when it is determined that the input value is lower than the predetermined temperature, a turn-off signal is output to turn off the first warning lamp 46a.

Further, the CPU 52 uses the sensor unit 1
Power source 30 transmitted from antenna 4 through antennas 32 and 40
The output of the voltage sensor that indicates the output voltage of the
Compare with.

When the input value is judged to be less than the predetermined voltage in the voltage comparison block 52d, the CPU 52 outputs a lighting instruction signal to turn on the second warning lamp 46b, and at the same time, it is judged that the input value is not less than the predetermined voltage. When it is turned off, a turn-off instruction signal is output to turn off the second warning lamp 46b.

The operating power source will be described. As shown in FIG. 4, in the monitoring unit 20, the indicator 46 is an on-vehicle battery power source 56 mounted on the vehicle 12.
When the user turns on the ignition switch 58, it is energized and an operation (display) power source is supplied.

On the other hand, in the monitoring unit 20,
The CPU 52 is connected via a constant power supply circuit 62 to a second battery power supply 60 provided independently of the vehicle-mounted battery power supply 56. As described above, since the power source 30 of the sensor unit 16 is a lithium battery, the sensor unit 1
Reference numeral 6 also detects (measures) and outputs an output indicating a tire air pressure and the like even when the ignition switch 58 is turned off, that is, when the engine (not shown) of the vehicle 12 is stopped, and the monitoring unit 20 constantly outputs the output. The transmission is received and it is determined whether or not the tire pressure is appropriate as described later.

The operation switch 64 is inserted in the power supply circuit between the second battery power source 60 and the indicator 46. When the operation switch 64 is turned on, the second battery power source 60 is connected to the indicator 46. Is configured to supply its operating power. The operation switch 64 is
As shown in FIG. 1, it is arranged inside the vehicle 12, that is, adjacent to the indicator 46 arranged on the dashboard of the driver's seat so that the user can operate it.

Further, the indicator 46 is the CPU 5
2 to the first and second warning lights 46a and 46b and the panel 46
When a lighting instruction signal such as c is output, the output is sent to the switching circuit 66 via the signal line 481 to turn on the switching circuit 66 to turn on the in-vehicle battery power source 56.
Operating power is supplied from. That is, the indicator 46
When the CPU 52 determines that the tire air pressure or the like is not appropriate, the LED is turned on regardless of whether the ignition switch 58 is on or off, so that the user can easily perform the start-up inspection. When operating power is supplied to the indicator 46, a signal of the operating power is supplied to the CPU 5 via the signal line 482 (and a delay circuit (not shown)).
2, the CPU 52 recognizes the activation of the indicator 46 after the delay time.

FIG. 6 is a time chart showing the operation of the CPU 52 for detecting and transmitting the tire air pressure and the like.

FIG. 6A is a time chart when the tire air pressure is in a proper state, that is, when the tire air pressure is at least less than the first predetermined value and not less than the second predetermined value. Note that, in addition to the tire air pressure being in a proper state, a case where the tire temperature is lower than a predetermined temperature may be regarded as a proper tire air pressure.

In such an appropriate case, the CPU 22 in the sensor unit 16 causes the measurement cycle (for example, 7
The sensor output is A / D converted and input (read) every (sec), and the input value (detection value) is transmitted to the monitoring unit 20 every transmission cycle (for example, 4.0 min to 8.0 min). The transmission cycle is slightly shifted for each of the four sensor units 16.

The transmitting antenna 3 of the sensor unit 16
Data transmission from 2 through the receiving antenna 40 of the monitoring unit 20 is performed at a frequency of 315 MHz. Further, as described later, data transmission from the transmission antenna 42 of the monitoring unit 20 via the reception antenna 34 of the sensor unit 16 is also performed at the same frequency.

The transmission data from the sensor unit 16 is, as shown in FIG. 7, an ID pulse train (described later), other pressure sensor output (digital conversion value), temperature sensor output (digital conversion value), and voltage sensor. One unit of, for example, a 56-bit signal (32-bit ID pulse train, 8-bit pulse train each indicating pressure sensor output, temperature sensor output, and voltage sensor output) combined in the order of pulse trains indicating output (digital conversion value) Configured as.

The ID pulse train is as shown in the lower part of FIG.
One set of (4
Bar code attached to each of the tires 14). That is, when the vehicle 12 is shipped from the factory, the bar code is separately provided for each of the four tires such as 14 FL described above, and is also separately provided when the vehicle 12 is different. Therefore, one barcode (ID
The pulse train) specifies one tire in the target vehicle group.

As described above, in the monitoring unit 20, the CPU 52 causes the input value (detected tire air pressure) of any one of the four tires 14 to be equal to or greater than the first predetermined value or the second value.
When it is determined to be less than the predetermined value of, the first warning lamp 46a of the indicator 46 is turned on and the transmission cycle switching signal is output to the sensor unit 16 via the transmitting antenna 42 and the receiving antenna 34.
At that time, the above-mentioned ID pulse train is added and transmitted.

Therefore, in any of the sensor units 16a to 16d specified by the ID pulse train, the corresponding CPU 22 recognizes that the transmission cycle switching signal is a command directed to itself and switches the transmission cycle.

Further, after the user purchases the vehicle 12,
Since the rotation of the tire 14 may be performed, the CPU 52 in the monitoring unit 20 transmits the four transmission data from the transmission antenna 32 of the sensor unit 16 and the reception antenna 40 of the monitoring unit 20. , The data having the highest reception intensity (radio field intensity) is determined as the transmission data from the sensor unit 16 of the corresponding tire.

The receiving antenna 40FR will be specifically described as an example. When the tire closest to the receiving antenna 40FR is 14FR as shown in FIG. 1 above, the receiving intensity of the receiving antenna 40FR is the highest among the transmission data of four tires sequentially transmitted at each transmission interval. The higher one is the signal from the sensor unit 16FR,
The CPU 52 determines the transmission data from the sensor unit 16FR as information on the right front wheel FR of the vehicle. On the other hand, as a result of the rotation of the tire 14, the reception antenna 4
The tire closest to 0FR is 14RL, so the sensor unit closest to the receiving antenna 40FR is 16RL.
Then, the reception antenna 40FR has the highest reception intensity of the transmission data from the sensor unit 16RL. The CPU 52 discriminates the transmission data from the sensor unit 16RL having the highest reception intensity as the information of the right front wheel of the vehicle, and the ID pulse indicating the right front wheel of the vehicle written in the CPU 52 is detected from the sensor unit 16FR. Replace with unit 16RL.

Returning to the explanation of FIG. 6, FIG. 6 (b) shows the time when the above-mentioned proper condition is not satisfied, that is, when the tire air pressure is equal to or higher than the first predetermined value or lower than the second predetermined value. It is a chart.

In that case, the monitoring unit 20
Outputs the transmission cycle switching signal as described above. Therefore, the sensor unit 16 A / D-converts and reads the sensor output at the same measurement cycle (for example, 7 seconds), and shortens the transmission cycle according to the transmission cycle switching signal, for example, 7.0 seconds.

This is because the power storage capacity of the power source 30 of the sensor unit 16 is limited, so that as long as the tire air pressure is in a proper state, the transmission cycle is lengthened to avoid the consumption of the power source voltage as much as possible. At the same time, when it is determined that the tire air pressure is not in an appropriate state, it is desirable to increase the monitoring frequency and promptly notify.

In the tire pressure monitoring device according to this embodiment, as described above, the pressures which are arranged on each of the four (plural) tires 14 mounted on the vehicle 12 and which produce an output indicative of the tire pressure. A sensor unit 16 including at least a sensor 24 and a transmitting antenna 32 that transmits the output of the pressure sensor 24, and a receiving antenna 40 that is mounted on the vehicle 12 and that receives the output transmitted from the sensor unit 16
It is received through to determine whether the air pressure of the tire is appropriate by comparing with a predetermined value, more accurately, the output of the pressure sensor 24 is compared with a first predetermined value and a second predetermined value, It is mounted on the vehicle 12 and the monitoring unit 20 that determines whether the tire air pressure of the second predetermined value or more is less than the predetermined value of 1 and is in an appropriate state, and displays the determination result on the indicator (notification unit) 46. In the tire air pressure monitoring device 10 including the vehicle-mounted battery power source 56 that supplies the operating power to the indicator (notification unit) 46 via the ignition switch 58, a second battery power source 60 provided separately from the vehicle-mounted battery power source 56 And an operation switch 64 which is arranged inside the vehicle 12 and which connects the second battery power source 60 to the indicator (notification unit) 46 and supplies operation power by the operation of the user. It was constructed as.

Thus, when the user gets out of the vehicle 12 and fills the air of the tire 14 whose air pressure has dropped, the indicator 46 is simply operated by operating the operation switch 64 in the vehicle compartment without turning on the ignition switch 58. Can be displayed to confirm the tire that needs to be filled, so that the air filling work becomes easy.

When outputting the transmission cycle switching signal, the monitoring unit 20 adds the ID pulse train (identification signal) for specifying the tire 14 for which the air pressure is determined to be not proper to the transmission data and outputs it. So 4
Since it is possible to shorten the transmission cycle of only the sensor units 16 mounted on the tires 14 that are determined to have an improper air pressure or the like, instead of all the sensor units 16, it is possible to reduce the consumption of the power supply 30. it can.

FIG. 8 is a block diagram similar to FIG. 4, showing a second embodiment of the tire pressure monitoring device according to the present invention.

Explaining focusing on the points different from the first embodiment, in the tire pressure monitoring device according to the second embodiment, the remote keyless entry (portable terminal) 50 receives the third signal. While arranging the antenna 50a, providing a second indicator (notification unit) 50b,
Therefore, the above-described determination result is displayed on the indicator 50b via the second transmitting antenna 42 and the third receiving antenna 50a according to the user's instruction.

That is, the remote keyless entry 50 is
Although a transmission antenna 50d for transmitting a lock signal and an unlock signal of the door of the vehicle 12 is intrinsically built in through the operation button 50c, in addition to that, a reception antenna 50a is arranged and an indicator 50b and a first indicator as shown in the figure are provided. The second operation button 50e is provided. The second operation button 50e is for inputting a user's instruction.

As described above, the transmission frequency between the monitoring unit 20 and the sensor unit 16 is 315 MHz, but since the remote keyless entry 50 also generally uses the same frequency for transmission, a receiving antenna 50a or the like is added. However, the change of the circuit is small.

As a result, in the monitoring unit 20, the user's instruction issued by pressing the second operation button 50e is sent to the CPU via the transmitting antenna 50d and the receiving antenna 40.
When it is transmitted to 52, the determination result can be displayed on the indicator 50b via the transmitting antenna 42 and the receiving antenna 50a. The rest of the configuration is the same as that of the first embodiment.

The pattern (graphic) displayed on the indicator 50b is the same as the panel 46c of the indicator 46. Reference numerals 50f and 50g denote warning lights similar to the first and second warning lights 46a and 46b of the indicator 46.

Incidentally, the pattern displayed on the indicator 50b is not limited to that shown in the figure, and the air pressure state may be shown for each tire using a pattern as shown in FIG. In FIG. 9, the diagonal cross hatching between the front and rear left FL and RL indicates that the tire pressure is normal, the vertical line hatching on the front right FR indicates insufficient tire pressure, and the diagonal hatching on the rear right RR indicates excessive tire pressure. Actually, the difference in hatching is shown by color. For example, it is shown in blue when the tire pressure is normal, in yellow when the tire pressure is insufficient, and in red when the tire pressure is excessive.

Further, a pattern as shown in FIG. 10 may be used. In FIG. 10, in addition to the state display of the tire air pressure by the hatching described above, the adjustment direction (increase / decrease direction) of the air pressure is indicated by an arrow. Front left and right F
Since the R and RL tires are normal, the arrow is solid and the front right FR is lacking, so the upward arrow is hatched similarly to indicate insufficient air pressure, and the rear right RR is also Similar hatching indicating excess air pressure was applied to the downward arrow.

Furthermore, the state of air pressure may be shown for each tire using a pie chart-like pattern as shown in FIG. 11, and as shown in FIG. 12, the adjustment direction may also be shown. . In FIG. 12, since the tire on the front right side FR has insufficient air pressure, hatching indicating insufficient pressure is performed on the lower side, and the tire on the rear right side RR has excessive air pressure, and therefore hatching indicating excess pressure is performed on the upper side. It was applied to. That is, when the hatching is applied to the lower side, it is necessary to adjust the air pressure in the increasing direction, and when the hatching is applied to the upper side, it is necessary to adjust the air pressure in the decreasing direction. The patterns shown in FIGS. 11 and 12 have the advantage of using less space than those of FIGS. 9 and 10.

In the second embodiment, as described above, the vehicle 12 is used.
The output of a sensor (pressure sensor 24) that produces an output indicating the air pressure of the four (plurality) tires 14 mounted on the vehicle is a predetermined value, more accurately, a first predetermined value indicating excess air pressure and insufficient air pressure. In a tire pressure monitoring device 10 including a monitoring unit 20 that determines whether or not the tire pressure is proper by comparing with a second predetermined value, a remote keyless entry (portable terminal device) carried by a user outside the vehicle 12. ) 50 is provided with an informing section (indicator 50b) for informing the user of the result of the above-mentioned determination, so that the user can easily check the tire pressure from the outside of the vehicle at the start-up inspection before boarding.
Although the indicator 50b is visually informed to the user, it may be informed by voice.
Furthermore, both may be used.

More precisely, each of the four (plural) tires 14 mounted on the vehicle 12 is provided with a pressure sensor 24 which produces an output indicative of tire pressure, and a first sensor which transmits the output of the pressure sensor. Sensor unit 16 including at least the transmitting antenna 32 of the tire and the output transmitted from the sensor unit 16 mounted on the vehicle 12 via the first receiving antenna 40 and compared with a predetermined value to compare the air pressure of the tire 14. Is compared with a first predetermined value indicating insufficient air pressure and a second predetermined value indicating excess air pressure to determine whether the air pressure of the tire 14 is within an appropriate range. In the tire pressure monitoring device 10 provided with the monitoring unit 20 that makes the determination and displays the determination result on the indicator (first notification unit) 46, A transmitting antenna 42 of the vehicle 1
2, a remote keyless entry (portable terminal) 50 carried by a user outside the second key, and a third receiving antenna 50a (second key) arranged in the remote keyless entry 50.
Receiving antenna) and an indicator (second notification unit) 50b provided in the remote keyless entry 50, and the monitoring unit 20 is input according to a user's instruction, that is, by operating the second operation button 50e. The second transmitting antenna 42 according to the user's instruction
Then, the above-mentioned determination result is displayed on the indicator 50b via the third receiving antenna 50a.

As a result, the user can easily check the tire pressure from the outside of the vehicle 12 at the start-up inspection before boarding the vehicle. Incidentally, the indicators 46, 50
Although b informs visually, it is also possible to inform audibly, or both of them may be the same as described above.

Although the portable terminal device is the remote keyless entry 50 as described above, it may be either a portable telephone device or a PHS telephone device. Since the transmission frequency of the remote keyless entry 50 is the same as the transmission frequency of the tire pressure monitoring device 10 shown in the figure, the remote keyless entry 50 is preferable,
When the frequency is different from the transmission frequency of the tire pressure monitoring device in a mobile phone or the like, an appropriate multiplication circuit may be added.

In any case, by using such a portable terminal device, the user can easily and quickly check the tire pressure from the outside of the vehicle at the start-up inspection before boarding the vehicle.

The indicator 50b of the remote keyless entry 50 also displays the determination result including the tire air pressure condition. Therefore, the predetermined values are the first predetermined value indicating the excess value and the insufficient value. If the second predetermined value shown is used, the user can recognize and adjust the tire air pressure excess or deficiency state by the display of the notification unit, so that the air filling work becomes easier.

Further, when the result of the above-mentioned judgment indicates that the air pressure of one or more of the four tires is not proper, the monitoring unit 20 indicates that the air pressures of the four tires are as shown in FIGS. 10 and 12. The display also shows the adjustment direction. As a result, the adjustment direction of the air pressure, that is, whether the air should be filled or deflated, is also displayed, and the air filling operation is further facilitated.

Further, since the portable terminal device is configured to be either the remote keyless entry 50 or the portable telephone device and the PHS telephone device, the user holds the remote keyless entry 50 or the like at hand and fills the air. Therefore, the work becomes easier.

[0077]

According to the first aspect of the present invention, the portable terminal unit carried by the user outside the vehicle is provided with an informing unit for informing the user of the result of determination as to whether or not the tire pressure is proper. With this configuration, the user can easily check the tire pressure from the outside of the vehicle at the start-up inspection before boarding the vehicle.

In the second aspect, the monitoring unit is
According to the user's instruction, the second transmitting antenna and the second receiving antenna are used to display the result of determination as to whether or not the tire pressure is appropriate, on the second notification unit provided in the mobile terminal device. Similar to the item 1, the user can easily check the tire pressure from the outside of the vehicle at the start-up inspection before getting on the vehicle.

According to the third aspect of the present invention, since the portable terminal is any one of a remote keyless entry, a portable telephone, and a PHS telephone, the user is required to check the tires before starting the ride. The air pressure can be checked easily and quickly from outside the vehicle.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an overall tire air pressure monitoring device according to an embodiment of the present invention.

FIG. 2 is an explanatory sectional view showing the structure of a sensor unit in the apparatus shown in FIG.

FIG. 3 is a block diagram showing in detail the configuration of the main body of the sensor unit in the apparatus shown in FIG.

4 is an explanatory block diagram showing in detail the configuration of the main body of the monitoring unit in FIG.

5 is an explanatory block diagram functionally showing the operation of the CPU of the main body of the monitoring unit in FIG.

FIG. 6 is a time chart showing a detection / transmission operation of the sensor unit of FIG.

FIG. 7 is an explanatory diagram showing a configuration of transmission data of the sensor unit of FIG.

FIG. 8 is an explanatory block diagram similar to FIG. 4, showing an operation of the tire air pressure monitoring device according to the second embodiment of the present invention.

FIG. 9 is an explanatory diagram showing another example of the display pattern (graphic) of the indicator of the remote keyless entry of the tire air pressure monitoring device according to the second embodiment shown in FIG.

FIG. 10 is an explanatory diagram showing still another example of the display pattern (graphic) of the indicator of the remote keyless entry of the tire pressure monitoring device according to the second embodiment shown in FIG.

FIG. 11 is an explanatory diagram showing still another example of the display pattern (graphic) of the indicator of the remote keyless entry of the tire pressure monitoring device according to the second embodiment shown in FIG.

FIG. 12 is an explanatory diagram showing still another example of the display pattern (graphic) of the indicator of the remote keyless entry of the tire pressure monitoring device according to the second embodiment shown in FIG.

[Explanation of symbols]

10 Tire Pressure Monitoring Device 12 Vehicle 14 Tire 16 Sensor Unit 22 CPU (Sensor Unit) 24 Pressure Sensor 32 Transmission Antenna (First Transmission Antenna) 40 Reception Antenna (First Reception Antenna) 42 Transmission Antenna (Second Transmission) Antenna) 46 indicator (first notification unit) 50 remote keyless entry (portable terminal) 50a remote keyless entry reception antenna (second reception antenna) 50b remote keyless entry indicator (second notification unit) 50e remote keyless Entry second operation button 52 CPU (of monitoring unit)

Claims (3)

[Claims] 1. A tire air pressure monitor comprising a monitoring unit for comparing the output of a sensor which produces an air pressure output of a plurality of tires mounted on a vehicle with a predetermined value to determine whether the air pressure of the tire is proper or not. In the device, a tire air pressure monitoring device characterized in that a portable terminal device carried by a user outside the vehicle is provided with an informing unit for informing the user of the result of the determination. 2. A. A sensor unit disposed on each of a plurality of tires mounted on the vehicle, the sensor unit including at least a pressure sensor that generates an output indicating a tire pressure and a first transmitting antenna that transmits the output of the pressure sensor; b. Mounted on the vehicle, the output transmitted from the sensor unit is received via the first receiving antenna and compared with a predetermined value to determine whether the tire air pressure is appropriate,
A tire pressure monitoring device comprising: a monitoring unit that displays the determination result on the first notification unit; c. A second transmitting antenna located on the monitoring unit; d. A mobile terminal carried by a user outside the vehicle; e. A second receiving antenna arranged in the mobile terminal; f. A second notification unit provided in the mobile terminal device; and the monitoring unit, in accordance with an instruction from the user, outputs the determination result to the second transmission antenna and the second reception antenna via the second transmission antenna and the second reception antenna. A tire pressure monitoring device, which is displayed on a notification section of the tire. 3. The tire pressure monitoring device according to claim 1, wherein the mobile terminal is one of a remote keyless entry, a mobile phone and a PHS phone.