JP2003220810A - Tire pneumatic pressure alarm device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To notify a driver of a travelable distance when drop in pneumatic pressure in a tire is detected in a run flat tire. <P>SOLUTION: The tire pneumatic pressure alarm device comprises a pneumatic pressure detecting means for detecting the pneumatic pressure in a tire, a pneumatic pressure drop discriminating means for discriminating the pneumatic pressure in the tire drops lower than a predetermined set value, a remaining traveling distance calculating means for integrating a travel distance of a vehicle from the time when the pneumatic pressure in the tire drops lower than the set value and for calculating the remaining traveling distance being the distance between a predetermined distance and the integrated traveling distance, a display means for displaying the remaining traveling distance, a traveling distance discriminating means for discriminating that the remaining traveling distance is lower than a predetermined threshold value, and a alarming means for giving an alarm when the remaining traveling distance is lower than the predetermined threshold value. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire air pressure alarm device, and more particularly to a tire air pressure alarm device for detecting a decrease in air pressure in a run flat tire and automatically issuing an alarm.

[0002]

2. Description of the Related Art In order to ensure the safe running of a vehicle, it is necessary to always set the tire air pressure of the vehicle to an appropriate state. For example, when the tire air pressure decreases, the occurrence rate of punctures increases, and at high speeds,
Bursts can occur, causing serious accidents.

For this reason, conventionally, various tire pressure warning devices have been proposed, such as WO01 / 19626A1 or WO01 / 17806A1, which detect a decrease in tire air pressure and give a warning to the driver. . As a device for measuring the tire air pressure, AB
Known methods include a method of indirectly estimating the tire air pressure by inputting data from the S speed sensor, and a method of directly measuring the tire air pressure by the air pressure sensor. Further, in the system disclosed in the above publication, the tire temperature is monitored to detect an abnormality in the tire air pressure to warn the driver.

However, even if the driver receives a tire pressure drop warning, the tires may not be replaced immediately on the spot depending on the condition of driving on the highway or other road conditions. On the other hand, in recent years, run-flat tires have been developed that can travel a certain distance even if the tire pressure becomes zero due to a flat tire. Run-flat tires include a core type with a metal or synthetic resin ring-shaped core attached to the rim of the tire's air chamber, and a relatively rigid cross section on the inner surface of the tire sidewall. There is known a side-reinforcing type in which a rubber layer is arranged and reinforced. Of these, the core type has a high load-bearing capacity for run-flat traveling, so it is suitable for vehicles that carry four or more wheels.
The side reinforcement type is used for passenger cars or two-wheeled vehicles.

[0005]

A run-flat tire is capable of running to some extent even if the tire is flat, so it is difficult to notice the flat tire. Therefore, a tire pressure warning device for detecting an abnormality in the tire air pressure and notifying the driver is indispensable. It is said that. However, in the conventional tire pressure alarm device,
The driver simply didn't know how much more he could run because he simply notified the tire pressure drop. Therefore, even if it is notified that the tire pressure has dropped, the fact that the tire is a run-flat tire may cause it to continue to run beyond the specified speed and specified distance, which may lead to a serious situation. It was

The present invention has been made in view of the above-mentioned conventional problems, and in a pneumatic tire, especially a run flat tire, when a decrease in tire air pressure is detected, the vehicle can travel thereafter. An object of the present invention is to provide a tire pressure warning device that allows the driver to take appropriate measures by notifying the driver of whether or not the tire pressure is informed.

[0007]

In order to solve the above problems, the present invention provides a tire air pressure detecting means for detecting tire air pressure, a tire air pressure detecting signal from the tire air pressure detecting means, and the tire air pressure detecting means. When the air pressure in the tire is determined to be lower than the set value, the running distance of the vehicle from that time is integrated. The remaining travel distance calculating means for calculating the remaining travel distance, which is the difference between the predetermined travel distance after the preset decrease in the air pressure and the accumulated travel distance, and the display for displaying the remaining travel distance. Means, a travel distance determining means for determining that the remaining travel distance is below a predetermined threshold, and a predetermined alarm when it is determined that the remaining travel distance is below the predetermined threshold. Further comprising a, a warning means for emitting to provide a tire pressure warning system according to claim.

The alarm means is a lamp, a buzzer,
It is preferable that the alarm means is a means for issuing an alarm by means of at least one of voices.

Further, the tire air pressure warning device further comprises speed determining means for determining that the traveling speed of the vehicle has exceeded a preset predetermined speed, and the traveling speed exceeds the predetermined speed. It is preferable that the warning means gives a warning when the judgment is made.

Further, in the tire pressure warning device, when the speed determining means determines that the traveling speed of the vehicle exceeds the predetermined speed, the remaining traveling speed is determined according to the traveling speed of the vehicle. It is preferable to include a remaining travel distance correcting means for correcting the distance.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The tire pressure warning device of the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings. The present invention, in a vehicle equipped with run-flat tires, when the tire pressure is lower than a predetermined value, the driver is warned by displaying to the driver how much more the vehicle can run, and the driver is warned according to the situation at that time. Will be able to determine what action to take thereafter.

FIG. 1 is a block diagram showing a schematic configuration of a tire pressure warning device according to an embodiment of the present invention. As shown in FIG. 1, the tire pressure warning device 1 of the present embodiment
Is mainly an air pressure sensor 1 for detecting the tire air pressure.
0, a control means 12 for receiving various signals such as an air pressure detection signal and making various judgments and processing, a display means 14 for displaying various information and warnings according to the judgment result of the control means 12, and a driver in a serious situation. It is configured to have an alarm means 16 for issuing an alarm notifying that there is something.

The control means 12 is a core portion of the tire pressure warning device 1 of the present invention.
It includes a remaining travel distance calculation means 20, a travel distance determination means 22, a speed determination means 24, and a remaining travel distance correction means 26. The air pressure drop determination means 18 receives the air pressure detection signal from the air pressure sensor 10 and determines whether or not the tire air pressure has fallen below a preset predetermined value. As a predetermined value that serves as a reference for determining this decrease in air pressure, for example, 80% of the normal air pressure of the tire is exemplified. That is, according to this predetermined value, when 20% of the tire's normal air pressure is released and the air pressure drops, it is determined that the air pressure has dropped, and an air pressure drop signal is sent to the remaining travel distance calculation means 20.

The vehicle in this embodiment is equipped with a run flat tire, and the air pressure sensor 10 is attached to the rim portion of the wheel. The run flat tire is not particularly limited and may be a core type or a side reinforcing type. The air pressure sensor 10 is also not particularly limited, and is, for example, attached to a wheel rim portion and has a diaphragm made of an elastic material such as silicon rubber in an opening in the tire communicating with the inside of the tire. The deformation of the diaphragm may be detected as a change in capacitance, or may be another type. Also,
The air pressure sensor 10 is provided with a transmitter (wireless transmission device) that wirelessly transmits a detection signal, and constitutes a sensor tag. The detected tire air pressure detection signal is wirelessly transmitted by the wireless transmission device provided in the air pressure sensor 10 that constitutes the sensor tag. This signal is received by the wireless receiving device provided on the vehicle body side near the tire and is sent to the air pressure drop determining means 18 of the control means 12.

Alternatively, as the tire air pressure detecting means, other than the one in which the tire air pressure is directly measured by the air pressure sensor, for example, the tire air pressure of each wheel is determined based on the wheel speed detected by the wheel speed sensor. It may be one that is calculated and indirectly obtained.
In any case, it is sufficient as long as it has a function of detecting the air pressure in the tire and sequentially sending the air pressure detection signal to the air pressure drop determination means 18 of the control means 12.

When the remaining running distance calculating means 20 receives from the air pressure drop determining means 18 an air pressure drop signal indicating that the tire air pressure has dropped below the predetermined value, the running distance calculation means 20 starts integrating the running distance of the vehicle. . This mileage integration is performed by a mileage sensor (cumulative distance meter) 28, such as a magnet type or an electronic type, which detects rotation of an output shaft of a transmission normally mounted on a vehicle.
It is done by receiving a signal from. The remaining travel distance calculating means 20 integrates the travel distance of the vehicle after the air pressure drop is detected, and subtracts this from a preset predetermined safe travel distance after the air pressure drop (the travel limit km number). , Calculate the remaining travel distance.

The predetermined safe traveling distance after the air pressure drop is set by the run-flat tire mounted on the vehicle, for example, even if the tire air pressure becomes 0, the vehicle can travel at 80 km / h for 80 km. It is determined by the standard that the vehicle can travel 100 km at a speed of 60 km per hour. Remaining mileage calculation means 20
Calculates the remaining travel distance (remaining safe travel distance) by subtracting the integrated distance traveled by the vehicle after detection of the decrease in air pressure from the predetermined distance determined by the standard of 80 km or 100 km.

The remaining traveling distance calculated by the remaining traveling distance calculating means 20 is displayed on the display means 14. Display means 1
4 is, for example, installed in the instrument panel near the driver's seat, displays that the tire pressure (at least one of the tires) has dropped, and then displays the remaining travel distance that can be safely traveled, Encourage the driver to change tires at the nearest tire shop as soon as possible.

The remaining traveling distance calculated by the remaining traveling distance calculating means 20 is also sent to the traveling distance determining means 22. The traveling distance determining means 22 determines whether or not the remaining safe traveling distance is below a predetermined threshold value set in advance. The predetermined threshold value is appropriately set, for example, a distance of 10% of the limit number of kilometers traveled. When the remaining travel distance is less than this threshold value, it is considered that the travel distance after the tire air pressure has dropped reaches the safe travelable distance (travel limit km), and the travel distance determination means 22 causes the display means 14 and the alarm means. A signal is sent to 16 to display a warning on the display means 14, and an alarm is issued from the warning means 16. The alarm means 16 is not particularly limited,
It comprises an alarm lamp provided near the driver's seat, a buzzer that emits an alarm sound, or an audio device that issues an alarm sound from a speaker. The alarms are these lamps, buzzers,
Any one of the voices or the like, or a plurality of these may be used in combination.

As mentioned above, the remaining safe traveling distance is, for example, 80 km / h when traveling at a speed within a prescribed (predetermined) speed, such as 80 km / h.
This is a guaranteed distance, and when the vehicle travels at a speed higher than the predetermined speed, the situation changes and the remaining travel distance is not always guaranteed. In such a case, it is necessary to correct the remaining travel distance.

Therefore, a speed determining means 24 and a remaining travel distance correcting means 26 are provided. Speed determination means 2
4 receives a signal from a vehicle speed sensor 30 normally provided in the vehicle and determines whether or not the traveling speed of the vehicle exceeds a predetermined speed. This predetermined speed is, for example, 80 km / h depending on the run-flat tire mounted on the vehicle.
It is a speed that is specified as "etc." When the speed determination means 24 determines that the vehicle traveling speed exceeds a predetermined (specified) speed, a signal indicating that the vehicle has exceeded the predetermined speed and its excess speed are sent to the remaining travel distance correction means 26.

When the remaining travel distance correction means 26 receives a signal indicating that the predetermined speed is exceeded from the speed determination means 24, the remaining travel distance calculation means 20 receives the accumulated travel distance at that time, and in response to this, Make corrections. This correction is performed by subjecting the integrated travel distance to a coefficient process of multiplying a predetermined coefficient greater than 1 in accordance with the speed amount exceeding the predetermined speed detected by the speed determination means 24. That is, when the vehicle travels at a speed higher than the predetermined speed, the traveling distance is corrected so that the traveling distance is greater than the actual traveling distance so that the remaining traveling distance is reduced.

As described above, when the vehicle travels at a speed exceeding the predetermined speed, the remaining travel distance correcting means 26 makes a correction so as to increase the accumulated travel distance according to the excess for safety. . The corrected total mileage is
It is sent to the mileage discriminating means 22, and the mileage discriminating means 22
Then, thereafter, the traveling distance is integrated with respect to the corrected integrated traveling distance, and the result is subtracted from the predetermined distance to calculate the remaining traveling distance. Therefore, when traveling at a speed exceeding the predetermined speed, depending on the excess,
The remaining mileage becomes smaller. The traveling distance determination means 22 determines whether or not to issue an alarm by comparing the remaining traveling distance thus corrected with a predetermined threshold value.

At this time, even if the remaining travel distance has not yet reached the threshold value, the traveling speed is too high. Therefore, the warning means 16 issues an alarm so that the driver can drive at a lower speed. May be warned. Also, even if the driver slows down due to this warning and travels at a speed within the predetermined speed, no correction is made to increase the remaining running distance again. Is calculated. In addition, when the vehicle speed exceeds the predetermined speed, the remaining travel distance may be multiplied by a coefficient smaller than 1 to directly correct the remaining travel distance. However, in this case,
Subsequent integration processing becomes somewhat complicated.

The operation of this embodiment will be described below with reference to the flow chart of FIG. First, step 100
In, it is assumed that a decrease in tire air pressure is detected. This decrease in the air pressure is detected by the air pressure decrease determining means 18 receiving an air pressure detection signal from the air pressure sensor 10 and determining at all times, for example, at regular time intervals while the vehicle is traveling. Upon receiving the air pressure detection signal, the air pressure drop determination means 18 compares it with a predetermined set value to determine whether the tire air pressure has dropped. As described above, the set value is, for example, a value that is 20% lower than the normal air pressure. However, the set value is not limited to this, and the type of the run flat tire mounted and the running condition of the vehicle (running) It is appropriately set according to the history).

When a decrease in tire air pressure is detected, in the next step 110, the remaining travel distance calculating means 20 starts integration of the travel distance after detection of the decrease in air pressure.
When the remaining running distance calculation means 20 receives the air pressure drop detection signal, it clears the previous running distance integrated value to 0, receives running distance data from the running distance sensor 28, and integrates the running distance. The integrated value may be cleared when the tire whose air pressure has dropped is replaced.

In step 120, the remaining travel distance calculating means 20 subtracts the cumulative travel distance after the decrease in air pressure from a preset predetermined safe travel distance after the decrease in air pressure (travel limit number of kilometers), Calculate the remaining mileage.
The calculated remaining travel distance is sent to the travel distance determination means 22 and the display means 14. The display unit 14 displays the remaining traveling distance to the driver together with a warning message indicating that the tire pressure has decreased. In this way, by not only issuing a warning that the tire pressure has dropped, but also displaying the remaining mileage, the driver can think of a coping method such as how far to travel and where to replace the tire. .

In step 130, the speed determination means 2
No. 4 receives the vehicle traveling speed data from the vehicle speed sensor 30 at a constant time interval after the vehicle traveling hollow pressure drop is detected, and the traveling speed does not exceed the predetermined speed compared with a predetermined speed set in advance. Determine whether. In this determination, if the traveling speed does not exceed the predetermined speed in traveling after the air pressure is reduced, in the next step 140, it is determined whether or not the remaining traveling distance is less than a preset threshold value in the traveling distance determining means 22. To be determined.

This threshold value is set in advance in order to prevent the driver from traveling beyond the traveling limit kilometer after the air pressure is reduced. For example, the traveling limit kilometer, that is, a predetermined distance that allows safe traveling after the air pressure is reduced. However, the present invention is not limited to this. In the mileage judging means 22, the remaining mileage is compared with the threshold value, and if the remaining mileage is not equal to or less than the threshold value, the process returns to step 120 to integrate the mileage after the reduction of the air pressure and the remaining amount. The steps of calculating the traveling distance, determining the traveling speed, and comparing the remaining traveling distance with the threshold value are repeated.

If it is determined in step 140 that the remaining travel distance has become equal to or less than the threshold value, an alarm is issued in step 150. When the mileage judging means 22 judges that the remaining mileage is equal to or less than the threshold value, a signal is sent to the display means 14 and the alarm means 16.
When the display means 14 receives this signal, the display means 14 displays a message to the driver that the tires should be replaced immediately because the vehicle has reached the running limit km. Further, the warning means 16 gives a warning to the driver by using any one of a lamp, a buzzer, a voice, or a combination thereof.

When it is determined in step 130 that the traveling speed exceeds the preset predetermined speed, in step 160, the warning means 16
An alarm is issued to inform the driver that the speed is too high. Further, in step 170, when the remaining travel distance correction means 26 receives a signal indicating that the traveling speed exceeds the predetermined speed from the speed determination means 24, it receives the integrated travel distance from the remaining travel distance calculation means 20, and Is multiplied by a predetermined coefficient corresponding to the excess speed to correct the remaining travel distance.

As mentioned above, the run flat tire is
Even if the air pressure becomes 0 in advance, how many kilometers per hour and how many kilometers
Since it is specified that the vehicle can travel m, if the vehicle runs at a speed exceeding this specified speed (predetermined speed), it is not possible to guarantee the required limit number of kilometers, so the remaining travel distance is a safe range. It is modified so that The mileage judging means 22 uses the corrected remaining mileage to compare with a threshold value in step 140. The subsequent steps are the same as above.

As described above, since the remaining travel (possible) distance after the tire pressure is lowered is displayed, the driver can appropriately respond to the tire pressure drop in consideration of road conditions. Becomes When the driver replaces a tire at the nearest tire shop or the like, it is preferable that all the remaining mileage integration routines be automatically reset. With the automatic reset function, it is possible to prevent the driver from forgetting to reset in the case of manual operation, and to ensure correct operation of the system.

When the tire is punctured while the vehicle is running, the air temperature inside the tire rises sharply.
By detecting not only the air pressure inside the tire but also the air temperature inside the tire and using this temperature information together with the air pressure information, it is possible to more reliably detect the tire pressure drop due to a flat tire. Therefore, it is preferable that a temperature sensor is also attached to the air pressure sensor attached to the tire rim portion, and the temperature detection signal is wirelessly transmitted to the vehicle-side receiving device by the wireless transmitting device.

Although the tire pressure warning device of the present invention has been described in detail above, the present invention is not limited to the above embodiments, and various improvements and changes are made without departing from the gist of the present invention. Of course you may go.

[0036]

As described above, according to the present invention, after detecting the decrease in tire air pressure, the remaining running distance up to the limit number of kilometers that can be safely traveled is displayed to the driver. It is possible for the driver to take appropriate measures against the tire pressure drop due to.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a tire pressure warning device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the present embodiment.

[Explanation of symbols]

1 Tire pressure alarm device 10 Air pressure sensor 12 Control means 14 Display means 16 Alarm means 18 Air pressure drop determination means 20 Remaining mileage calculation means 22 mileage determination means 24 Speed judgment means 26 Remaining mileage correction means 28 mileage sensor 30 vehicle speed sensor

Claims (4)

[Claims] 1. A tire air pressure detecting means for detecting tire air pressure, and a tire air pressure detecting means for receiving a tire air pressure detection signal from the tire air pressure detecting means to determine that the tire air pressure has dropped below a predetermined set value. When it is determined that the air pressure inside the tire has dropped below the set value, the running distance of the vehicle from that point is integrated, and a predetermined distance that allows safe running after a preset air pressure drop And a remaining travel distance calculating means for calculating a remaining travel distance which is a difference between the accumulated travel distance, a display means for displaying the remaining travel distance, and the remaining travel distance falling below a predetermined threshold. And a warning means for issuing a predetermined warning when it is determined that the remaining travel distance is below the predetermined threshold value. Ya pressure warning system. 2. The tire air pressure warning device according to claim 1, wherein the warning means is a warning means that issues a warning by at least one of a lamp, a buzzer, and a sound. 3. The tire pressure warning device according to claim 1 or 2, further comprising speed determining means for determining that the traveling speed of the vehicle has exceeded a predetermined speed set in advance. The tire pressure warning device, wherein the warning means gives a warning when it is determined that the vehicle speed exceeds the predetermined speed. 4. The tire pressure warning device according to claim 3, further comprising: a traveling speed of the vehicle when the traveling speed of the vehicle is determined to exceed the predetermined speed by the speed determining means. A tire pressure warning device comprising: a remaining travel distance correcting means for correcting the remaining travel distance accordingly.