JP2008013145A - Tire air pressure monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire air pressure monitoring device which emits warning according to a reduction displacement amount of a tire air pressure. <P>SOLUTION: In a receiving unit 6 for receiving tire air pressure information transmitted from a transmission unit 5, an air pressure displacement determination part 66 determines whether difference of the tire air pressure measured the last time and the tire air pressure measured this time is a set displacement amount or more, and issues warning even in the state in which the tire air pressure is higher than the set air pressure if the difference of the tire air pressure measured the last time and the tire air pressure measured this time is the set displacement amount or more. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention belongs to a technical field of a tire pressure monitoring device that receives tire pressure information detected by a tire pressure sensor attached to a tire of a vehicle by a receiver attached to a vehicle body and monitors each tire pressure.

As this type of technology, the technology described in Patent Document 1 is disclosed. In this publication, an alarm may be issued when the detected value of the tire air pressure changes around the stored alarm value.
JP 2000-99869 A

  If the decrease in tire air pressure is due to deterioration of the valve or the like, it is desirable to replace the valve. It is also desirable to avoid the risk of sudden bursts except for the nail when the nail is pierced and the air is gradually removed even before the tire pressure falls below the alarm value.

  However, in the above-described prior art, an alarm is given that the tire air pressure has dropped, so there is a problem that it is difficult to notice the situation where the tires are easily pulled out and the valve is deteriorated or light burst.

  The present invention has been made paying attention to the above-mentioned problems, and an object of the present invention is to provide a tire pressure monitoring device capable of issuing an alarm to a tire in a state where air is gradually removed. It is in.

  In order to achieve the above object, in the present invention, there are a plurality of tire pressure detectors that detect each tire pressure and a transmitter that transmits a radio signal including at least tire pressure information. From the transmission means attached to each of the tires and the tire air pressure information included in the radio signal, a tire air pressure lowering judgment unit for judging that the tire air pressure is lower than the set air pressure, and the tire air pressure is lower than the set air pressure. Tire pressure monitoring, comprising: an alarm unit that issues an alarm to the driver and a receiving unit that receives a radio signal transmitted from the transmitting unit, and a receiving unit that is attached to the vehicle body side In the apparatus, the receiving means is provided with tire pressure displacement determining means for determining that the displacement amount of the tire air pressure per predetermined time is equal to or greater than the set displacement amount. It means, when the displacement amount per predetermined time of the tire air pressure is equal to or greater than the set amount of displacement was an alarm to the driver even when tire pressure is greater than the predetermined air pressure.

  Even if the tire air pressure is higher than the set air pressure, an alarm can be issued if the displacement amount of the tire air pressure per predetermined time is equal to or greater than the set displacement amount. Therefore, the occupant can grasp the tire in which the air is easily removed in advance than the tire air pressure is lower than the set air pressure. Therefore, it is possible to prompt the occupant to perform maintenance / inspection work such as tire inspection and valve replacement / inspection by means of an alarm.

  Hereinafter, the best mode for carrying out the present invention will be described based on Example 1 and Example 2.

  First, the configuration will be described.

  FIG. 1 is an overall system diagram showing a vehicle to which the tire pressure monitoring apparatus according to the first embodiment is applied. The tire pressure monitoring device includes a right front wheel tire 1, a left front wheel tire 2, a right rear wheel tire 3, and a left rear wheel tire 4. Each tire is provided with a transmission unit 5 that detects the tire pressure and transmits the detected tire pressure information in a packet. The vehicle is provided with a receiving unit 6 that receives a packet transmitted by each transmitting unit 5.

[Configuration of transmission unit]
FIG. 2 is a block diagram showing the configuration of the transmission unit 5.

  The transmission unit 5 is provided with a centrifugal force switch 50, a tire pressure sensor 51, a battery 52, a control unit 53, an RF signal transmission unit 54, and an RF signal transmission antenna 55. The transmission unit 5 corresponds to the transmission means of the present invention, the tire pressure sensor 51 corresponds to the tire pressure detection unit of the present invention, and the RF signal transmission unit 54 and the RF signal transmission antenna 55 correspond to the transmission unit of the present invention.

  Centrifugal force switch 50 determines whether the vehicle is traveling or stopped based on the centrifugal force generated by the rotation of the wheels. The centrifugal force switch 50 is turned on while the vehicle is running and turned off when the vehicle is stopped, and outputs respective signals to the control unit 53.

  The tire pressure sensor 51 detects the tire pressure and outputs it to the control unit 53 as tire pressure information.

  The control unit 53 inputs ON / OFF signal information from the centrifugal force switch 50 and tire air pressure information from the tire air pressure sensor 51, calculates from each information, and outputs a control signal to the RF signal transmission unit 54. In addition, power is supplied from the battery 52 to the control unit 53.

  The RF signal transmission unit 54 generates an RF signal to be transmitted from the RF signal transmission antenna 55 based on the control signal input from the control unit 53, and transmits the RF signal from the RF signal transmission antenna 55 to the reception unit 6.

[Receiver configuration]
Next, the configuration of the receiving unit 6 will be described.

  FIG. 3 is a block diagram showing the configuration of the receiving unit 6.

  The receiving unit 6 is provided with an RF signal receiving antenna 60, an RF signal receiving unit 61, a stabilized power supply 62, a control unit 63, and an alarm device 64. The receiving unit 6 corresponds to the receiving means of the present invention, the RF signal receiving antenna 60 and the RF signal receiving unit 61 correspond to the receiving unit of the present invention, and the alarm device 64 corresponds to the alarming unit of the present invention.

  The RF signal receiving antenna 60 receives the RF signal from the receiving unit 6.

  The RF signal receiving unit 61 outputs tire pressure information of the RF signal received by the RF signal receiving antenna 60 to the control unit 63.

  The control unit 63 includes an air pressure decrease determination unit 65, an air pressure displacement determination unit 66, and an alarm output unit 67. The control unit 63 is supplied with power from the stabilized power source 62.

  The air pressure decrease determination unit 65 determines whether the tire air pressure has decreased below the set air pressure from the tire air pressure information input from the RF signal receiving unit 61, and outputs the determination result to the alarm output unit 67.

  The air pressure displacement determination unit 66 compares the tire air pressure information input from the RF signal receiving unit 61 this time with the tire air pressure information input last time, and determines whether or not the displacement amount is greater than or equal to the set displacement amount. The determination result is output to the alarm output unit 67.

  The alarm output unit 67 outputs a control signal to the alarm device 64 according to the determination result input from the air pressure decrease determination unit 65 or the air pressure displacement determination unit 66. In addition, the alarm output part 67 comprises the alarm part of this invention with the alarm device 64. FIG.

  The alarm device 64 gives an alarm to the occupant by sound, light, image, vibration or the like. The alarm method is not limited to sound, light, image, vibration, or the like as long as the occupant can recognize a decrease in tire air pressure.

  Next, the operation will be described.

  When the tire air pressure decreases, running stability and fuel consumption deteriorate. The first purpose of the tire pressure monitoring device is to prompt the occupant to fill the tires with air when the tire pressure has dropped to such an extent that the running stability or fuel consumption deteriorates, To restore normal tire pressure.

  First, an outline of the operation of a conventional tire pressure monitoring device that achieves the above object will be described.

[Conventional tire pressure monitoring processing]
FIG. 4 is a flowchart showing a flow of processing performed in a conventional tire pressure monitoring apparatus.

  In step S1, tire pressure information is extracted from the received RF signal, processed as tire pressure information, and the process proceeds to step S2.

  In step S2, tire pressure information is stored, and the process proceeds to step S3.

  In step S3, it is determined whether or not the tire air pressure is equal to or lower than a set air pressure. If the tire pressure is less than or equal to the set air pressure, the process proceeds to step S4. If the tire pressure is higher than the set air pressure, the process returns to step S1.

  In step S4, a process for alarming is performed, and the process proceeds to step S5.

  In step S5, an alarm is issued.

[Conventional tire pressure monitoring]
FIG. 5 is a diagram for explaining the detected tire pressure and alarm generation in a conventional tire pressure monitoring device.

  As shown in FIG. 5, conventionally, an alarm was not issued unless the tire air pressure was lower than the set air pressure.

  If the decrease in tire air pressure is due to deterioration of the valve or the like, it is desirable to replace the valve. It is also desirable to avoid the risk of sudden bursts except for the nail when the nail is pierced and the air is gradually removed even before the tire pressure falls below the alarm value.

  However, in the conventional tire pressure monitoring device, since the alarm is not issued until the tire pressure falls below the set pressure, it is difficult to grasp the decrease in the tire pressure in advance than the tire pressure falls below the set pressure. Therefore, there is a possibility that an alarm cannot be issued to the tire in a state where air is gradually removed.

  In addition, a set air pressure (second set air pressure) may be separately provided in the normal tire pressure range as an alarm for a state in which the tire air pressure is reduced although it is within the normal tire pressure range. Conceivable. However, even if the tire pressure drops due to normal use, a warning is issued if the tire pressure falls below the second set air pressure. For the passenger, a warning is issued despite the fact that the vehicle is normally used, and there is a risk that it will be annoying.

  Therefore, in Example 1, if the amount of decrease in the tire air pressure per predetermined time is greater than or equal to the set displacement, an alarm is issued even if the tire air pressure is higher than the set air pressure. In the first embodiment, when an abnormal decrease in tire air pressure occurs due to, for example, road surface condition or use environment, by looking at the amount of displacement, this causes a different influence on normal driving, particularly fuel efficiency. The vehicle is allowed to travel in a good state at all times by giving an early warning that the vehicle will be affected.

[Tire pressure monitoring process]
FIG. 6 is a flowchart showing a flow of processing performed in the tire pressure monitoring apparatus of the first embodiment.

  In step S11, tire pressure information is extracted from the received RF signal, processed as tire pressure information, and the process proceeds to step S12.

  In step S12, tire pressure information is stored, and the process proceeds to step S13.

  In step S13, it is determined whether the tire air pressure is equal to or lower than a set air pressure. If the tire air pressure is less than or equal to the set air pressure, the process proceeds to step S15, and if it is higher than the set air pressure, the process proceeds to step S14.

  In step S14, it is determined whether or not the displacement amount per predetermined time of the currently detected tire air pressure is greater than or equal to the set displacement amount with respect to the previously detected tire air pressure. When the displacement amount is equal to or larger than the set displacement amount, the process proceeds to step S15, and when it is lower than the set displacement amount, the process returns to step S11. Here, the predetermined time is set by experiment or calculation based on the amount of displacement when the tire air pressure naturally decreases.

  In step S15, a process for giving an alarm is performed, and the process proceeds to step S16.

  In step S16, an alarm is issued.

[Tire pressure monitoring]
FIG. 7 is a diagram illustrating the detected tire pressure and alarm generation in the tire pressure device of the first embodiment. In FIG. 7, the tire pressure is measured every predetermined time.

  As shown in FIG. 7, since the tire air pressure measured from the n1th time to the n3th time is constant at P1 and higher than the set air pressure, the alarm device 64 does not issue an alarm. The tire pressure measured at the n4th time is P2 (<P1), but since the displacement (P1-P2) of the tire pressure is smaller than the set displacement amount and higher than the set air pressure, the alarm device 64 does not issue an alarm. . The tire pressure measured at the n5th time is P3 (<P2), but since the displacement of the tire pressure (P2-P3) is smaller than the set displacement amount and higher than the set air pressure, the alarm device 64 similarly does not issue an alarm.

  On the other hand, the tire air pressure measured at the n6th time is P4 (<P3), and the displacement of the tire air pressure (P3-P4) is larger than the set displacement amount. In this case, although the tire air pressure P4 is higher than the set air pressure, the alarm device 64 issues an alarm.

  As described above, even if the tire air pressure is higher than the set air pressure, if the difference (displacement amount per predetermined time) between the tire air pressure measured last time and the tire air pressure measured this time is equal to or greater than the set displacement amount, An alarm was made. Therefore, the occupant can grasp the decrease in the tire air pressure in advance before the tire air pressure falls below the set air pressure. For this reason, it is possible to prompt the occupant to perform maintenance / inspection work such as filling the tire pressure or replacing / inspecting the valve in advance.

  Next, effects of the tire pressure monitoring apparatus according to the first embodiment will be described.

  (1) A tire pressure sensor 51 (tire pressure detector) that detects the air pressure of the tire 1 and an RF signal transmission that transmits tire pressure information as a radio signal to a transmission unit 5 (transmission means) provided in each tire 1 And an RF signal transmission antenna 55 (transmission unit).

  Also included in the radio signal are an RF signal receiving antenna 60 and an RF signal receiving unit 61 (receiving unit) that receive the radio signal transmitted from the transmitting unit 5 in the receiving unit 6 (receiving means) provided on the vehicle body side. From the information on the tire pressure to be determined, an air pressure decrease determining unit 65 (tire pressure decrease determining means) for determining that the tire air pressure is equal to or lower than the set air pressure, and determining that the displacement amount of the tire air pressure is greater than or equal to the set displacement amount An air pressure displacement determining unit 66 (tire pressure displacement determining means) that performs an alarm to the driver when the tire air pressure is less than or equal to the set air pressure, or when the amount of displacement per predetermined time of the tire air pressure is greater than or equal to the set displacement amount An output unit 67 and an alarm device 64 (alarm unit) were provided.

  Therefore, even if the tire air pressure is higher than the set air pressure, an alarm can be issued if the displacement amount per predetermined time is equal to or greater than the set displacement amount. Therefore, an alarm can be issued to a tire in a state where air is gradually removed.

  In the first embodiment, an alarm is issued when the displacement amount of one tire due to the passage of time is greater than or equal to the set displacement amount. On the other hand, the second embodiment is different in that a warning is issued when the displacement amount of the other tires with the air pressure is abnormal in the set displacement amount.

  First, the configuration of the second embodiment will be described. About the structure similar to Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the configuration of the second embodiment, the pneumatic displacement determination unit 66 of the control unit 63 of the receiving unit 6 is different from the first embodiment.

  In the first embodiment, the air pressure displacement determination unit 66 compares the tire air pressure information input from the RF signal receiving unit 61 this time with the tire air pressure information input last time, and the displacement amount is equal to or larger than the set displacement amount. Or not, and outputs the determination result to the alarm output unit 67.

  On the other hand, in the second embodiment, the air pressure displacement determination unit 66, for example, the tire air pressure information of the left rear wheel tire 4 (RL) input from the RF signal receiving unit 61, the right front wheel tire 1 (FL), and the left front wheel tire 2 (FR) and the tire pressure information of the right rear wheel tire 3 (RR) are compared to determine whether or not the displacement amount is equal to or greater than the set displacement amount, and the determination result is output to the alarm output unit 67. To do.

  Next, the operation will be described.

  For example, if the pressure of any tire does not fall below the set air pressure, but only the pressure of one tire is reduced, it is desirable to fill the tire pressure to balance the air pressure of the other tires.

  Therefore, in Example 2, when the air pressure of a certain tire is lower than the air pressure of other tires, an alarm is issued even if the tire air pressure is equal to or higher than the set air pressure.

[Tire pressure monitoring process]
FIG. 8 is a flowchart showing a flow of processing performed in the tire pressure monitoring apparatus of the second embodiment.

  In step S11, tire pressure information is extracted from the received RF signal, processed as tire pressure information, and the process proceeds to step S12.

  In step S12, tire pressure information is stored, and the process proceeds to step S13.

  In step S13, it is determined whether the tire air pressure is equal to or lower than a set air pressure. If the tire air pressure is less than or equal to the set air pressure, the process proceeds to step S15, and if it is higher than the set air pressure, the process proceeds to step S17.

  In step S17, it is determined whether or not the amount of displacement between the tire air pressures is greater than or equal to the set amount of displacement. If the displacement amount is greater than or equal to the set displacement amount, the process proceeds to step S15.

  In the second embodiment, whether or not the displacement amount between the tire pressures is equal to or greater than the set displacement amount is determined by comparing the tire pressure values adjacent to each other, not comparing the highest value and the lowest value. Make a comparison. For example, if the tire pressure is higher in the order of right front wheel tire 1 (FR), left front wheel tire 2 (FL), right rear wheel tire 3 (RR), and left rear wheel tire 4 (RL), the right rear wheel tire 3 (RR) is compared with the air pressure values of the left front wheel tire 2 (FL) and the left rear wheel tire 4 (RL).

  In step S15, a process for giving an alarm is performed, and the process proceeds to step S16.

  In step S16, an alarm is issued.

[Tire pressure monitoring]
FIG. 9 is a diagram for explaining the detected tire pressure and generation of an alarm in the tire pressure device of the first embodiment.

  As shown in FIG. 9, the tires are a right front wheel tire 1 (FR), a left front wheel tire 2 (FL), a right rear wheel tire 3 (RR), and a left rear wheel tire 4 (RL) in descending order of tire pressure. And The displacement amount of the tire air pressure of the right front wheel tire 1 (FR) and the left front wheel tire 2 (FL) and the displacement amount of the left front wheel tire 2 (FL) and the right rear wheel tire 3 (RR) are smaller than the set displacement amount. On the other hand, since the displacement amount of the right rear wheel tire 3 (RR) and the left rear wheel tire 4 (RL) is equal to or larger than the set displacement amount, the alarm device 64 issues an alarm.

  By the above action, for example, an alarm can be issued even when the air pressure of any tire is not lower than the set air pressure, but the pressure of only one tire is reduced. Therefore, it is possible to prompt the occupant to fill the tire pressure and balance the air pressure of other tires.

  Next, effects of the second embodiment will be described.

  (2) A tire pressure sensor 51 (tire pressure detector) for detecting the air pressure of the tire 1 and an RF signal transmission for transmitting tire pressure information as a radio signal to a transmission unit 5 (transmission means) provided in each tire 1 And an RF signal transmission antenna 55 (transmission unit).

  Also included in the radio signal are an RF signal receiving antenna 60 and an RF signal receiving unit 61 (receiving unit) that receive the radio signal transmitted from the transmitting unit 5 in the receiving unit 6 (receiving means) provided on the vehicle body side. The tire pressure drop determining unit 65 (tire pressure drop judging means) for judging that the tire pressure is equal to or lower than the set air pressure from the information on the tire pressure, and the displacement amount of the tire air pressure with respect to the air pressure of other tires is greater than or equal to the set displacement amount. A tire pressure displacement determining unit 66 (tire pressure displacement determining means) that determines that the tire pressure has been reached, and alerts the driver when the tire pressure is less than or equal to the set air pressure, or when the tire air pressure displacement amount is greater than or equal to the set displacement amount. An alarm output unit 67 and an alarm device 64 (alarm unit) are provided.

  Therefore, for example, even if the air pressure of any tire does not become lower than the set air pressure, it is possible to issue an alarm even when only the pressure of one tire is reduced. Therefore, it is possible to prompt the occupant to fill the tire pressure and balance the air pressure of other tires.

(Other examples)
As described above, the best mode for carrying out the present invention has been described based on the first and second embodiments. However, the specific configuration of the present invention is not limited to the first or second embodiment. Absent.

  For example, when a keyless entry system is mounted on a vehicle, tire pressure information may be transmitted to the portable terminal when the driver goes out of the vehicle.

1 is an overall system diagram of a tire pressure monitoring device according to a first embodiment. 3 is a block diagram of a transmission unit according to Embodiment 1. FIG. 2 is a block diagram of a receiving unit according to Embodiment 1. FIG. It is a flowchart which shows the flow of a process of the conventional tire pressure monitoring apparatus. It is a figure explaining generation | occurrence | production of the tire pressure detected and the alarm in the conventional tire pressure monitoring apparatus. It is a flowchart which shows the flow of a process of the tire pressure monitoring apparatus of Example 1. FIG. It is a figure explaining the tire pressure detected in the tire pressure monitoring device of Example 1, and generation of an alarm. It is a flowchart which shows the flow of a process of the tire pressure monitoring apparatus of Example 2. FIG. It is a figure explaining the tire pressure detected in the tire pressure monitoring device of Example 2, and generation of an alarm.

Explanation of symbols

1 right front wheel tire 2 left front wheel tire 3 right rear wheel tire 4 left rear wheel tire 5 transmitting unit 51 tire pressure sensor 53 control unit 54 RF signal transmitting unit 55 RF signal transmitting antenna 6 receiving unit 60 RF signal receiving antenna 61 RF signal receiving Unit 63 Control unit 64 Alarm 65 Air pressure drop determination unit 66 Air pressure displacement determination unit 67 Alarm output unit

Claims (2)

A tire pressure detector for detecting each tire pressure;
A transmission unit for transmitting a radio signal including at least information on the tire pressure;
A transmission means attached to each of a plurality of tires mounted on the vehicle,
From the tire pressure information included in the wireless signal, a tire pressure drop determination unit that determines that the tire pressure is equal to or lower than a set air pressure;
An alarm unit that issues an alarm to the driver when the tire pressure falls below a set air pressure;
A receiver for receiving a radio signal transmitted from the transmitter;
Receiving means attached to the vehicle body side,
In a tire pressure monitoring device comprising:
The receiving means is provided with tire pressure displacement determining means for determining that the displacement amount of the tire air pressure per predetermined time is equal to or greater than a set displacement amount,
The warning means issues a warning to the driver even when the tire air pressure is greater than the set air pressure when the displacement amount per predetermined time of the tire air pressure is equal to or greater than a set displacement amount. A tire pressure monitoring device. A tire pressure detector for detecting each tire pressure;
A transmission unit for transmitting a radio signal including at least information on the tire pressure;
A transmission means attached to each of a plurality of tires mounted on the vehicle,
From the tire pressure information included in the wireless signal, a tire pressure drop determination unit that determines that the tire pressure is equal to or lower than a set air pressure;
An alarm unit that issues an alarm to the driver when the tire pressure falls below a set air pressure;
A receiver for receiving a radio signal transmitted from the transmitter;
Receiving means attached to the vehicle body side,
In a tire pressure monitoring device comprising:
The receiving means is provided with tire air pressure displacement determining means for determining that the displacement amount of the tire air pressure with respect to the air pressure of another tire is equal to or greater than a set displacement amount,
The alarm means alerts the driver even when the tire air pressure is greater than the set air pressure when the displacement of the tire air pressure with respect to the air pressure of another tire is greater than or equal to a set displacement. A tire pressure monitoring device characterized by performing.

Images