WO2008007531A1

WO2008007531A1 - Tire air pressure monitoring device

Info

Publication number: WO2008007531A1
Application number: PCT/JP2007/062679
Authority: WO
Inventors: Tatsumi Iida
Original assignee: Calsonic Kansei Corporation
Priority date: 2006-07-10
Filing date: 2007-06-25
Publication date: 2008-01-17
Also published as: JP2008013145A

Abstract

A tire air pressure monitoring device has a transmission unit (5) provided on the tire side, detecting tire air pressure, and transmitting information on the tire air pressure and also has a reception unit (6) provided on the vehicle body side and receiving the information on the tire air pressure. A tire air pressure change determination section (66) of the reception unit (6) determines whether a difference between a tire air pressure obtained in the preceding measurement and a tire air pressure obtained in measurement of this time is greater than or equal to a preset change amount. If the difference is greater than or equal to the presetchange amount, the tire air pressure monitoring device issues an alarm even if the tire air pressure is higher than a preset air pressure.

Description

Specification

Tire pressure monitoring device

Technical field

[0001] The present invention relates to a tire air pressure monitoring device that receives tire air pressure information detected by a tire air pressure sensor attached to a tire of a vehicle by a receiver attached to the vehicle body and monitors each tire air pressure. Belonging to the field.

Background art

[0002] As this type of technology, the technology described in Patent Document 1 is disclosed. This conventional tire pressure monitor is composed of a tire pressure sensor provided on the tire side, a transmission CPU, a transmission unit, and a transmission antenna, and a reception antenna, a reception unit, and a reception device provided on the vehicle body side.

It has a receiving device consisting of a CPU and 1st to 3rd warning lights, detects tire air pressure every predetermined time, transmits this detected value with the transmitting device, receives the detected value with the receiving device, and the detected value becomes large If the three different values are reduced, the first and second warning lights will be issued in order according to the tire pressure drop.

Patent Document 1: Japanese Patent Laid-Open No. 2000-99869

Disclosure of the invention

Problems to be solved by the invention

[0003] 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 nails, when the nail is pierced and the air is gradually escaping, even before the tire pressure falls below the alarm value.

[0004] However, in the above-mentioned conventional technology, an alarm is given for the tire pressure drop, so it is difficult to recognize the situation where it is easy to come off, and it is difficult to notice deterioration of the valve, nail sticking, etc. There was a problem.

Hereinafter, this conventional problem will be specifically described.

[0006] [Conventional tire pressure monitoring processing]

Fig. 8 is a flowchart showing the flow of processing performed in a conventional tire pressure monitor. It is

[0007] In step SI, the RF signal force and tire pressure information received by the receiver is extracted.

The tire pressure information is processed and the process proceeds to step S2.

[0008] In step S2, the tire pressure information is stored, and the process proceeds to step S3.

[0009] In step S3, it is determined whether or not the tire air pressure is less than or equal to the set air pressure (Pl, P2,? 3; where 1 ³ 1>? 2> 3). If the tire pressure is less than or equal to the set air pressure P1 to P3, the process proceeds to step S4. If the tire pressure is higher than the set air pressure, the process returns to step S1.

[0010] In step S4, a process is performed to issue an alarm according to whether the set air pressure P1 to P3 is lower than the set air pressure of the deviation, and the process proceeds to step S5.

[0011] In step S5, the first to third warning lights are selected according to the result of step 4, and an alarm is issued.

[0012] [Conventional tire pressure monitoring function]

FIG. 9 is a diagram for explaining the detected tire pressure and alarm generation in a conventional tire pressure monitoring device.

[0013] As shown in FIG. 9, in the past, an alarm was not issued unless the tire air pressure dropped below the set air pressure.

[0014] Here, if the decrease in tire air pressure is due to deterioration of the nozzle 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 escaping, even before the tire pressure falls below the alarm value. ,.

[0015] However, in the conventional tire pressure monitoring device, since the alarm is not issued until the tire pressure falls below the set air pressure, the tire air pressure is lower than the set air pressure for tires in which air is gradually being removed. It will be difficult to grasp the decrease in tire pressure in advance. For this reason, tire failures cannot be detected until the alarm value falls below, and an alarm is not issued.

[0016] In this case, although it is within the normal tire pressure range, it is assumed that an alarm is issued for a state where the tire pressure drops! It is conceivable to provide atmospheric pressure (second set air pressure). However, even if the tire air pressure drops due to normal use, a warning is issued if the air pressure falls below the second set air pressure. For this reason, since the warning is issued to the passenger even though the vehicle is normally used, there is a risk that it may be annoying.

[0017] The present invention has been made by paying attention to the above-mentioned problems, and the object of the present invention is to make it possible to issue a warning earlier to a tire in a state where air is gradually removed. The object is to provide an air pressure monitoring device.

Means for solving the problem

[0018] In order to achieve the above object, in the present invention, there are a plurality of tire pressure detection units that detect each tire pressure, and a transmission unit that transmits a radio signal including at least tire pressure information. Tire pressure drop determining unit that determines that the tire pressure is less than the set air pressure based on the transmission means attached to each of the tires and the tire pressure information included in the radio signal. A tire pressure monitoring device comprising: a warning unit that issues a warning to the driver; a receiving unit that receives a radio signal transmitted from the transmission unit; and a reception unit that is attached to the vehicle body. In the above, 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. If the tire air pressure displacement determining means determines that the amount of displacement of the tire air pressure per predetermined time is equal to or greater than the set displacement amount, the means is provided to the driver even if the tire air pressure is greater than the set air pressure. To give an alarm.

The invention's effect

[0019] 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, it is possible for the occupant to know the tires that are easier to remove air in advance than the tire pressure falls below the set air pressure. For this reason, the warning can prompt the occupant to inspect tires such as nail sticks and replace valves, and to perform maintenance / inspection work.

Brief Description of Drawings

FIG. 1 is an overall system diagram of a tire air pressure monitoring device according to a first embodiment of the present invention. FIG. 2 is a block diagram of a transmission unit that constitutes the tire pressure monitoring apparatus according to the first embodiment.

FIG. 3 is a block diagram of a receiving unit constituting the tire air pressure monitoring device according to the first embodiment.

FIG. 4 is a flowchart showing a flow of tire pressure monitoring processing in the tire pressure monitoring device of Embodiment 1.

FIG. 5 is a diagram for explaining the detected tire pressure and alarm generation in the tire pressure monitoring apparatus of the first embodiment.

FIG. 6 is a flowchart showing the flow of tire pressure monitoring processing in the tire pressure monitoring device of Embodiment 2 according to the present invention.

FIG. 7 is a diagram for explaining tire pressure detected by the tire pressure monitoring apparatus of Example 2 and generation of an alarm.

FIG. 8 is a flow chart showing the flow of tire pressure monitoring processing in a conventional tire pressure monitoring device.

Explanation of symbols

1 Right front wheel tire

2 Left front wheel tire

3 Right rear wheel tire

4 Left rear wheel tire

5 Transmitter unit

51 Tire pressure sensor

53 Control unit

54 RF signal transmitter

55 RF signal transmission antenna

6 Receiver unit

60 RF signal receiving antenna

61 RF signal receiver 65 Air pressure drop judgment section

66 Pneumatic displacement judgment part

67 Alarm output section

BEST MODE FOR CARRYING OUT THE INVENTION

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

Example 1

[0023] First, the configuration of the tire pressure monitoring apparatus of the first embodiment will be described with reference to the accompanying drawings.

FIG. 1 is an overall system diagram showing a vehicle to which the tire pressure monitoring device of the first embodiment is applied. The tire pressure monitoring device is provided on each tire side of the right front wheel tire 1, the left front wheel tire 2, the right rear wheel tire 3, and the left rear wheel tire 4 to detect the tire air pressure, and to detect the detected tire air pressure information. A transmission unit 5 that transmits a packet is transmitted, and a reception unit 6 that is provided on the vehicle body 10 side and receives a packet transmitted by each transmission unit 5 is provided.

[0025] [Configuration of transmission unit]

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

The transmission unit 5 includes 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.

[0027] The centrifugal force switch 50 determines whether the vehicle is running or stopped based on the centrifugal force generated by the rotation of the wheels. Centrifugal force switch 50 is turned on while the vehicle is running and turned off when the vehicle is stopped, and each signal is output to control unit 53.

[0028] The tire pressure sensor 51 detects the tire pressure and outputs it to the control unit 53 as tire pressure information.

[0029] The control unit 53 inputs ON / OFF signal information from the centrifugal force switch 50 and tire pressure information from the tire pressure sensor 51 to perform calculation based on the respective information, and an RF signal transmission unit 54 Output a control signal. In addition, power is supplied from the battery 52 to the control unit 53.

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

[0031] [Configuration of receiving unit]

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

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

[0033] The receiving unit 6 is provided with an RF signal receiving antenna 60, an RF signal receiving unit 61, a stable power source 62, a control unit 63, and an alarm device 64. The receiving unit 6 is used as a receiving means of the present invention.

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

[0037] The air pressure decrease determination unit 65 is based on the tire air pressure information input from the RF signal receiving unit 61.

Then, it is determined whether or not the tire pressure is lower than the set air pressure, and the determination result is output to the alarm output unit 67.

[0038] The air pressure displacement determination unit 66 compares the tire air pressure information inputted from the RF signal receiving unit 61 this time with the tire air pressure information inputted last time, and determines whether or not the displacement amount is equal to or larger than the set displacement amount. The result of the determination is output to the alarm output unit 67.

The alarm output unit 67 outputs a control signal to the alarm device 64 in accordance with the determination result input from the air pressure decrease determination unit 65 or the air pressure displacement determination unit 66. The alarm output unit 67 and the alarm device 64 constitute an alarm unit of the present invention.

[0040] 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. [0041] Next, the operation of the tire pressure monitoring apparatus of the first embodiment will be described.

[0042] When the tire air pressure decreases, running stability, poor fuel consumption, and the like occur. The primary purpose of the tire pressure monitoring device is to fill the tires with the tires and to provide tire warnings when the tire pressure drops to such an extent that the running stability and fuel consumption deteriorate. This is to encourage repairs, etc., to restore normal tire pressure, or to reduce the running speed until repair.

[0043] Therefore, in the tire pressure monitoring device of the first embodiment, if the amount of decrease in tire pressure per predetermined time is equal to or greater than the set displacement, an alarm is issued even if the tire pressure is higher than the set pressure. I made it. In Example 1, when an abnormal decrease in tire air pressure occurs due to the road surface condition, usage environment, etc., by looking at the amount of displacement, this is the reason why this is different from normal for good driving, especially fuel consumption. By warning early on that it will have an impact, the vehicle can always run in good condition.

[0044] [Tire pressure monitoring process]

FIG. 4 is a flowchart showing the flow of the tire pressure monitoring process performed in the tire pressure monitoring apparatus of the first embodiment.

In step SI 1, the tire air pressure information is also extracted from the received RF signal force, processed as tire air pressure information, and the process proceeds to step S 12.

In step S 12, the tire pressure information is stored, and the process proceeds to step S 13.

[0047] In step S13, it is determined whether or not the tire air pressure is equal to or lower than the set air pressure. If the tire 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.

[0048] In step S14, it is determined whether or not the displacement amount per predetermined time of the currently detected tire air pressure with respect to the previously detected tire air pressure is greater than or equal to a set displacement amount. If the displacement is greater than or equal to the set displacement, the process proceeds to step S15. If the displacement is less than the set displacement, 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 pressure naturally decreases.

[0049] In step S15, processing for providing an alarm is performed, and the process proceeds to step S16.

[0050] In step S16, an alarm is issued. [0051] [Tire pressure monitoring function]

FIG. 5 is a diagram for explaining the detected tire pressure and alarm generation in the tire pressure device of the first embodiment. In Fig. 5, tire pressure is measured every predetermined time.

[0052] As shown in FIG. 5, the tire pressure measured from the nlth to the n3th time is constant at P1 and higher than the set air pressure, so the alarm device 64 does not issue an alarm. The tire pressure measured at the n4th time is P2 (P1), but the displacement of the tire pressure (P to P2) is smaller than the set displacement and higher than the set air pressure, so the alarm device 64 issues an alarm. do not do. nThe tire pressure measured at the fifth time is P3 ((P2), but the displacement of the tire pressure (P2-P3) is smaller than the set displacement amount.

[0053] On the other hand, the tire pressure measured at the n6th time is P4 (P3), and the displacement of the tire pressure (P3-P4) is larger than the set displacement amount. In this case, the tire pressure P4 is higher than the set pressure, but the alarm 64 issues an alarm.

[0054] As described above, even when the tire air pressure is higher than the set air pressure, the difference (displacement amount per predetermined time) between the tire air pressure measured last time and the tire air pressure measured this time is the set displacement amount. If so, an alarm was issued. Therefore, the occupant can grasp the decrease in the tire pressure in advance before the tire pressure falls below the set air pressure. For this reason, warnings can prompt passengers to perform maintenance and inspection tasks such as filling tire pressure and replacing / inspecting valves in advance.

Next, the effect of the tire pressure monitoring apparatus of Example 1 will be described.

[0056] (1) The tire pressure monitoring device of Example 1 includes a tire pressure sensor 51 (tire pressure detection unit) that detects the pressure of the tire 1 in a transmission unit 5 (transmission means) provided in each tire 1. And an RF signal transmitting unit 54 and an RF signal transmitting antenna 55 (transmitting unit) that transmit tire pressure information as a radio signal.

[0057] Further, an RF signal receiving antenna 60 and an RF signal receiving unit 61 (receiving unit) for receiving a radio signal transmitted from the transmitting unit 5 are connected to a receiving unit 6 (receiving unit) provided on the vehicle body side, From the tire pressure information included in the radio signal, 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, The air pressure displacement determining unit 66 (tire pressure displacement determining means) for determining that the displacement amount of the air pressure is equal to or greater than the set displacement amount, and the tire air pressure is less than the set air pressure or the displacement amount per predetermined time of the tire air pressure is the set displacement. The system is equipped with an alarm output unit 67 and an alarm device 64 (alarm unit) that alerts the driver when the amount exceeds the limit.

Therefore, even if the tire air pressure is higher than the set air pressure, an alarm can be issued if the displacement per predetermined time is equal to or greater than the set displacement. Therefore, a warning can be issued even earlier for tires in which air is gradually removed. Example 2

[0059] In Example 1, an alarm is issued when the displacement amount of one tire due to the passage of time is equal to or greater than the set displacement amount. On the other hand, Example 2 differs in that an alarm is issued when the amount of displacement of the other tires from the air pressure is equal to or greater than the set amount of displacement.

[0060] First, the configuration of the tire pressure monitoring apparatus of the second embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

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

[0062] In the tire pressure monitoring device of the first embodiment, the pneumatic displacement determination unit 66 compares the tire pressure information input from the RF signal receiving unit 61 this time with the tire pressure information input last time, and It is configured to determine whether or not the displacement amount is equal to or greater than the set displacement amount, and to output the determination result to the warning output unit 67.

On the other hand, in the tire air pressure monitoring device of the second embodiment, the air pressure displacement determining unit 66 includes, for example, the tire air pressure information of the left rear wheel tire 4 (RL) input from the RF signal receiving unit 61 and the right front wheel tire. Compare the tire pressure information of 1 (FL), left front wheel tire 2 (FR), and right rear wheel tire 3 (RR) to determine whether the displacement is greater than or equal to the set displacement. The result is output to the alarm output unit 67.

[0064] Next, the operation of the tire pressure monitoring apparatus of the second embodiment will be described.

[0065] For example, if the air pressure of any tire does not fall below the set air pressure, but the air pressure of only one tire falls, the tire pressure must be filled to balance with the air pressure of the other tire. Hope to do. [0066] Therefore, in Example 2, when the air pressure of a certain tire decreases and V rises with respect to the air pressure of another tire, an alarm is issued even if the tire air pressure is higher than the set air pressure.

[0067] [Tire pressure monitoring process]

FIG. 6 is a flowchart showing the flow of processing performed in the tire pressure monitoring apparatus of the second embodiment.

[0069] In step S12, the tire pressure information is stored, and the process proceeds to step S13.

[0070] In step S13, it is determined whether or not the tire air pressure is equal to or lower than the set air pressure. If the tire 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 S 17, it is determined whether or not the force between the tire air pressures is greater than or equal to the set displacement amount. If the displacement is greater than or equal to the set displacement, the process proceeds to step S15. If the displacement is lower than the set displacement !, the process returns to step S11.

[0072] In the tire pressure monitoring device of the second embodiment, whether or not the amount of displacement between the tire pressures is equal to or greater than the set displacement amount is not a comparison between the highest value and the lowest value of the tire pressure. Compare with adjacent tire pressure values. For example, if the tire pressure is right front wheel tire 1 (FR), left front wheel tire 2 (FL), right rear wheel tire 3 (RR), left rear wheel tire 4 (RL) in descending order of tire pressure, the right rear wheel Tire 3 (RR) is compared with the air pressure values of left front wheel tire 2 (FL) and left rear wheel tire 4 (RL).

[0073] In step S15, a process for alarming is performed, and the process proceeds to step S16.

[0074] In step S16, an alarm is issued.

[0075] [Tire pressure monitoring function]

FIG. 7 is a diagram for explaining the detected tire pressure and alarm generation in the tire pressure device of the first embodiment.

[0076] As shown in FIG. 7, in order of increasing tire pressure, right front wheel tire 1 (FR), left front wheel tire 2 (F), right rear wheel tire 3 (RR), left rear wheel tire 4 (RL) Tires. Right front wheel tire 1 (F

R) and left front tire 2 (FL) tire pressure displacement, left front tire 2 (FL) and right rear tire The displacement amount of 3 (RR) is smaller than the set displacement amount. On the other hand, since the displacement amount of the tires 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.

[0077] By the above-described action, for example, the pressure of any tire must be equal to or lower than the set air pressure V, but even if only one tire has a reduced pressure, an alarm can be issued. . Therefore, it is possible to prompt the occupant to fill the tire pressure and balance the air pressure of other tires.

Next, the effect of the tire pressure monitoring apparatus of Example 2 will be described.

[0079] (2) The tire pressure monitoring device of the second embodiment includes a tire pressure sensor 51 (tire pressure detection unit) that detects the pressure of the tire 1 in a transmission unit 5 (transmission means) provided in each tire 1. And an RF signal transmission unit 54 and an RF signal transmission antenna 55 (transmission unit) that transmit tire pressure information as a radio signal.

[0080] Further, an RF signal receiving antenna 60 and an RF signal receiving unit 61 (receiving unit) that receive a radio signal transmitted from the transmitting unit 5 are connected to a receiving unit 6 (receiving unit) provided on the vehicle body side, From the tire pressure information included in the radio signal, the tire pressure drop judging unit 65 (tire pressure drop judging means) for judging that the tire pressure is equal to or lower than the set air pressure, and the displacement of the tire pressure with respect to the air pressure of other tires. When the tire pressure is less than the set air pressure, or when the tire pressure displacement is greater than or equal to the set displacement amount The alarm output unit 67 and the alarm device 64 (alarm unit) for alarming the driver.

[0081] Therefore, for example, although the air pressure of any tire does not become equal to or lower than the set air pressure, an alarm can be issued even when only the pressure of one tire decreases. Therefore, it is possible to encourage 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 Example 1 and Example 2. However, the specific configuration of the present invention is limited to Example 1 or Example 2. is not. For example, when a vehicle is equipped with a keyless entry system, the tire pressure information may be transmitted to the portable terminal when the driver goes out of the vehicle.

Claims

The scope of the claims

[1] A tire pressure detection unit that detects each tire pressure and a transmission unit that transmits a radio signal including at least the tire pressure information, and is attached to each of a plurality of tires mounted on the vehicle. A transmission means,

A tire pressure drop determining unit that determines that the tire pressure is less than or equal to a set air pressure from information on the tire pressure included in the wireless signal. When the tire pressure is less than or equal to a set air pressure, An alarm unit that performs an alarm, and a receiver unit that receives a radio signal transmitted from the transmitter, and a receiver unit 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 alarm means determines that the tire air pressure is greater than the set air pressure when the tire air pressure displacement judging means judges that the amount of displacement of the tire air pressure per predetermined time is equal to or greater than a set displacement. A tire pressure monitoring device that warns the driver even if it exists.

[2] A tire pressure detection unit that detects each tire pressure and a transmission unit that transmits a radio signal including at least the tire pressure information, and is attached to each of a plurality of tires mounted on the vehicle Means,

In a tire pressure monitoring device comprising:

The receiving means is provided with tire air pressure displacement determining means for determining that the amount of displacement of the tire air pressure relative to the air pressure of other tires is greater than or equal to a set displacement amount,

The alarm means is adapted to detect the tire air pressure displacement judgment means against the air pressure of another tire. When it is determined that the displacement amount of the tire air pressure is greater than or equal to the set displacement amount, a warning is given to the driver even when the tire air pressure is greater than the set air pressure. Air pressure monitoring device.