JP2024018420A - Abnormality detection device for vehicle - Google Patents

Abstract

To provide an abnormality detection device for a vehicle which can detect, while suppressing increase of number of components, abnormality of a tire and vehicle members around the tire of a vehicle and output abnormality information.SOLUTION: An abnormality detection device for a vehicle comprises: tire condition detection means 31 which detects internal pressure and temperature of a vehicle tire; tire abnormality determination means 43a which determines abnormality of the tire based on the detected internal pressure and temperature of the tire; tire abnormality information output means 45a which generates tire abnormality information when abnormality of the tire is determined; ambient temperature detection means 42; determination threshold setting means 43c which sets a determination threshold value according to the detected ambient temperature; tire peripheral part high temperature determination means 43b which determines excessive temperature rise state of a bearing part around a wheel or a brake mechanism part when the detected internal temperature of tire is the determination threshold value or more; and abnormality information output means 45b which generates the excessive temperature rise information when the excessive temperature rise of the bearing part or the brake mechanism part is determined.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a vehicle abnormality detection device that detects abnormalities in vehicle tires and abnormalities in braking devices and bearing devices around the tires.

If an abnormality occurs in the air pressure or temperature of a tire while a vehicle is running, the risk of tire bursting or the like increases, which may lead to an accident. For this reason, devices (tire pressure monitoring systems, abbreviated as TPMS) have been developed that automatically monitor the air pressure and temperature of tires and issue an alarm when an abnormality occurs in the tires. For example, Patent Document 1 discloses a device in which a tire wheel is provided with means for detecting tire air pressure and temperature, and tire information obtained from the detecting means is displayed on a display section.

Furthermore, if the brake mechanism becomes abnormally heated, a fade phenomenon or a vapor lock phenomenon may occur, reducing the braking force and potentially leading to an accident. For this reason, devices have been developed that automatically monitor the temperature of the brake and issue an alarm if an abnormality occurs in the temperature of the brake mechanism. For example, Patent Document 2 discloses a device that is equipped with a brake temperature sensor that detects the temperature of the brake mechanism, and that predicts an abnormality in the brake mechanism based on changes in the temperature of the brake mechanism obtained from the brake temperature sensor and issues an alarm. ing.

Japanese Patent Application Publication No. 2003-121281 Japanese Patent Application Publication No. 10-44976

For safe vehicle operation, the above-mentioned tire pressure and temperature monitoring device (TPMS) and device that monitors the temperature of vehicle components around the tires, such as the brake mechanism, are effective, but it is necessary to install each device. In this case, cost increases are unavoidable. In addition, sensors that detect tire air pressure and temperature are attached to tire wheels, whereas brake temperature sensors, for example, are attached to the caliper of the brake mechanism, so there are not only sensor bodies but also harnesses, ECUs, and other parts. will increase. Therefore, there are concerns that the frequency of physical failures and maintenance costs will increase.

The present invention was developed with a focus on these issues, and it is possible to detect abnormalities in vehicle tires and vehicle components around the tires and output abnormality information while suppressing an increase in the number of parts. One of the purposes is to provide a vehicle abnormality detection device.

The present invention has been made to solve at least part of the above problems, and can be realized in the following aspects or application examples.
The vehicle abnormality detection device according to this application example is equipped on a vehicle, and is arranged on the outer rim of a wheel on which a tire is mounted, and includes a tire condition detection means for detecting the pressure and temperature inside the tire, and a tire condition detection means for detecting the pressure and temperature inside the tire. Tire abnormality determining means determines whether the tire is abnormal based on the pressure and temperature inside the tire detected by the detecting means, and if the tire abnormality determining means determines that the tire is abnormal, the tire abnormality information (for example, an alarm, a warning, etc.) is provided. tire abnormality information output means for emitting a light (such as a light, etc.); outside temperature detection means for detecting the outside temperature of the vehicle; and determination threshold setting means for setting a determination threshold according to the outside temperature detected by the outside temperature detection means. When the temperature inside the tire detected by the tire condition detection means exceeds the determination threshold, the bearing section that pivotally supports the wheel or the brake mechanism section disposed inside the wheel is overheated. If the tire peripheral high temperature determining means determines that the bearing or the brake mechanism is overheated, the tire peripheral high temperature determination means determines that the tire peripheral high temperature determination means is in the state of ).

According to this application example, tire abnormality is determined from the pressure and temperature inside the tire detected by the tire condition detection means, and when abnormality is determined, tire abnormality information is issued. Additionally, when the temperature inside the tire detected by the tire condition detection means exceeds the determination threshold, it is determined that the bearing that supports the wheel or the brake mechanism located inside the wheel is in an excessive temperature state. However, if excessive temperature rise is determined, abnormality information will be issued. In this way, the information detected by the tire condition detection means is used to detect abnormalities such as excessive temperature rise in the bearings or brake mechanism parts, which are vehicle components surrounding the tires, and issue abnormality information, thereby reducing the number of parts. It is possible to detect abnormalities in vehicle tires and vehicle components around the tires and output abnormality information while suppressing the abnormalities.
Further, since the determination threshold value for determining an abnormality in the bearing section or the brake mechanism section is corrected based on the outside temperature, the accuracy of abnormality determination can be improved.

According to the present invention, it is possible to detect an abnormality of excessive temperature rise in a tire of a vehicle and a vehicle component around the tire, such as a bearing or a brake mechanism, and output abnormality information, while suppressing an increase in the number of parts.

FIG. 1 is a block diagram showing a vehicle abnormality detection device according to an embodiment. FIG. 1 is a cross-sectional view showing essential parts of a tire for a vehicle according to an embodiment. 2 is a graph illustrating a relationship between a temperature rise due to use of the brake in the brake mechanism of the vehicle according to the embodiment and a temperature rise within the tire detected by the tire condition detection means. It is a graph explaining the setting of the determination threshold value used for excessive temperature rise determination of the brake mechanism part based on embodiment.

An embodiment of the present invention will be described with reference to the drawings. The following embodiment is merely an example, and there is no intention to exclude the application of various modifications and techniques not explicitly described in this embodiment. Each configuration of the embodiments described below can be modified in various ways without departing from the spirit thereof. Moreover, they can be selected or combined as necessary.

[1. composition]
[1.1. Configuration of wheels and surrounding areas]
FIG. 2 is a sectional view showing a main part of a rear wheel as an example of the wheel 11 of the vehicle (for example, a truck) 1. As shown in FIG. As shown in FIG. 2, the wheels 11 are pivotally supported by the vehicle body 10 via a suspension mechanism (not shown). This wheel 11 includes a wheel 12 and a tire 13 attached to an outer rim portion 12a of the wheel 12. The inner rim portion 12c of the wheel 12 is fastened to the flange portion 14a of the wheel hub 14 by fastening members (hub bolts 15a and wheel nuts 15b). A disk portion 12b having a lightweight hole (not shown) is provided between the outer rim portion 12a and the inner rim portion 12c of the wheel 12.

The wheel hub 14 is rotatably supported on the outer peripheral surface of the distal end side of the axle pipe 16 via a bearing portion 17 consisting of a pair of left and right roller bearings 17a and 17b. The axle pipe 16 is coupled to the tip of the axle housing. Further, an axle shaft 18 is inserted through the axle pipe 16, and a flange 18a on the tip side of the axle shaft 18 is connected to the wheel hub 14 by a connecting bolt 18b. As a result, the wheel hub 14 rotates together with the rotation of the axle shaft 18. Further, in the space within the wheel 12 of the wheel 11, a brake mechanism section 19 is provided between the wheel hub 14 side and the axle pipe 16 side. In this embodiment, a drum brake is employed as the brake mechanism section 19. However, the brake mechanism section 19 is not limited to a drum brake, and may be any mechanical brake that generates frictional heat, such as a disc brake.

[1.2. Tire pressure monitoring device]
The vehicle 1 is equipped with a vehicle abnormality detection device 20 including a tire pressure monitoring system (TPMS) 20A. FIG. 1 is a block diagram showing a vehicle abnormality detection device 20 according to this embodiment. As shown in FIG. 1, the abnormality detection device 20 includes a tire sensor unit 30 installed on the wheel 11 side (tire 13 side) and an abnormality detection unit 40 installed on the vehicle body 10 side.

As shown in FIG. 2, the tire sensor unit (tire sensor) 30 is disposed on the outer rim portion 12a of the wheel 12, and detects the pressure and temperature within the air chamber 13a of the tire 13. Here, in the outer circumferential rim part 12a of the wheel 12, a sensor part (tire condition detection means ) 31 are arranged. The pressure detection section 32 uses, for example, a pressure detection element, and the temperature detection section 33 uses, for example, a temperature detection element.

As shown in FIG. 1, this tire sensor unit 30 includes a signal processing section that processes detection signals output from a sensor section 31 (a pressure detection section 32 and a temperature detection section 33), a pressure detection section 32, and a temperature detection section 33. 34, a storage section 35 that stores various information such as programs, a transmission processing section 36 that transmits information processed by the signal processing section 34 using electromagnetic waves, and a battery 37 that is a power source.

The signal processing section 34 is configured by a CPU and operates according to a program stored in the storage section 35. The signal processing section 34 converts the analog detection signals outputted from the pressure detection section 32 and the temperature detection section 33 into digital signals at a predetermined period using an A/D conversion circuit (not shown), and converts the detected information taken in as digital values into digital signals. It is linked with the identification information and output to the transmission processing unit 36.

The transmission processing unit 36 includes a transmission circuit and a transmission antenna (not shown), and the transmission processing unit 36 transmits information sent from the signal processing unit 34 (detection information linked to identification information) to the transmission circuit. It transmits electromagnetic waves of a predetermined frequency from a transmitting antenna via a transmitting antenna.
Note that the battery 37 can be charged without contact, and the power charged in the battery 37 is used for the operation of the signal processing section 34, the storage section 35, and the transmission processing section 36.

As shown in FIG. 1, the abnormality detection unit 40 includes a reception processing section 41 that receives a signal transmitted from the tire sensor unit 30, and an outside temperature detection section (outside temperature detection means, outside temperature sensor) installed in the vehicle body 10. ) 42 , a signal processing section 43 that processes the detection signals output from the reception processing section 41 and the outside temperature detection section 42 , a storage section 44 that stores various information such as programs, and a signal processing section 43 and an information output unit (information output means) 45 that outputs the information.

The reception processing unit 41 includes a reception antenna and a reception circuit (not shown), and receives the electromagnetic waves transmitted from the tire sensor unit 30 using the reception antenna, and receives the received information (detection information linked to identification information). output as a digital signal.
The outside temperature detection section 42 detects the outside temperature around the vehicle and outputs the detected information as a digital signal.

The signal processing section 43 is configured by a CPU and operates according to a program stored in the storage section 44. The signal processing unit 43 includes, as functional elements, a tire abnormality determining unit (tire abnormality determining unit) 43a that determines whether the air pressure of the tire is abnormal, and a brake mechanism unit 19 disposed inside the wheel 12 that is in an excessive temperature state. A determination threshold is set according to the outside temperature detected by the tire peripheral high temperature determination section (tire peripheral high temperature determination means, also simply referred to as high temperature determination section) 43b and the outside temperature detection section 42. A determination threshold setting section (determination threshold setting means) 43c is provided.

The tire abnormality determining section 43a compares the pressure Pt and temperature Tt in the air chamber 13a of the tire 13 transmitted from the tire sensor unit 30 with threshold values stored in the storage section 44 to determine whether the tire 13 is abnormal. Here, the storage unit 44 stores an upper threshold Pts1 and a lower threshold Pts2 as thresholds for pressure (tire air pressure) Pt, and stores upper threshold Tts1 as a threshold for temperature (tire internal temperature) Tt. Note that the range of the pressure Pt from the lower limit threshold Pts2 to the upper limit threshold Pts1 is set as the appropriate air pressure for the tire 13. Further, the upper limit threshold Tts1 of the temperature Tt is set based on a temperature value that may cause high-temperature deterioration of the tire 13, and is set to a value of about 100° C., for example.

The tire abnormality determination unit 43a determines that the air pressure is excessive if the pressure Pt is larger than the upper limit threshold Pts1, and determines that the air pressure is insufficient if the pressure Pt is smaller than the lower limit threshold Pts2. If the temperature Tt is larger than the upper limit threshold Tts1, it is determined that the tire internal temperature is excessive. These determination results are sent to the information output section 45.

The tire peripheral high temperature determination unit 43b compares the temperature Tt in the air chamber 13a of the tire 13 with an excessive temperature rise determination threshold Ttss set by the determination threshold value setting unit 43c, and determines whether the temperature Tt in the air chamber 13a has increased excessively. When the temperature reaches or exceeds the temperature determination threshold Ttss, it is determined that the bearing portion 17 that pivotally supports the wheel 12 or the brake mechanism portion 19 disposed inside the wheel 12 is in an excessively heated state.
The determination threshold value setting unit 43c sets an excessive temperature rise determination threshold value Ttss based on the outside temperature around the vehicle detected by the outside temperature detection unit 42.

The tire peripheral high temperature determination section 43b uses the temperature Tt in the air chamber 13a of the tire 13 to determine whether the bearing section 17 that pivotally supports the wheel 12 or the brake mechanism section 19 disposed inside the wheel 12 is in an excessively heated state. Here, with reference to FIGS. 3 and 4, the relationship between the tire internal temperature Tt and the temperature of the bearing section 17 or the brake mechanism section 19 is determined based on tire peripheral high temperature determination and excessive temperature determination. Setting of the temperature increase determination threshold Ttss will be explained.

FIG. 3 shows the test results, where the horizontal axis is the number of brake operations, and the vertical axis is the tire internal temperature Tt and the temperature of the lining of the brake mechanism 19. The number of brake operations is the number of times the brake pedal is depressed at a predetermined period for a predetermined period of time. The tire internal temperature Tt at an outside temperature of 5° C., assuming a winter season, is shown by a circle, and the tire internal temperature Tt, at an outside temperature of 35° C., assuming a hot summer day, is shown by a □ mark. Also, the temperature of the lining depending on the number of brake operations is indicated by a △ mark.

As shown in FIG. 3, the temperature of the brake lining increases as the number of brake operations increases. Furthermore, as the number of brake operations increases, the tire internal temperature Tt also increases. However, the tire internal temperature Tt, which is relatively low compared to the brake lining temperature, is affected by the surrounding temperature (that is, the outside temperature), and the tire internal temperature Tt (marked with a circle) at an outside temperature of 5°C, assuming winter. On the other hand, the tire internal temperature Tt (marked by □) at an outside temperature of 35° C., which is assumed to be a very hot day in summer, shifts to the high temperature side.

Here, L1 is the increase characteristic line based on the temperature rise data of the tire internal temperature Tt (marked by □) at an outside temperature of 5°C, and the rise characteristic line is based on the temperature rise data of the tire internal temperature Tt (marked by □) at an outside temperature of 35°C. Assuming that the line is L2 and the rise characteristic line based on the brake lining temperature rise data is L3, L1, L2, and L3 are correlated with each other.

When the temperature of the brake lining increases, for example over 300° C., a fade phenomenon begins to occur. In this embodiment, even within this range, when the temperature of the brake lining reaches, for example, 350° C. or higher, an excessive temperature rise of the brake lining is determined so as to issue a warning.

The brake lining temperature of 350°C corresponds to approximately 80°C in the increase characteristic line L1 of the tire internal temperature Tt (marked with ◯) at an outside temperature of 5°C. Therefore, if the tire internal temperature Tt at an outside temperature of 5° C. is, for example, 80° C. or higher, it can be estimated that the brake lining is in an excessively heated state. In other words, the brake lining excessive temperature rise determination threshold Ttss is 80 (° C.).

Furthermore, if we focus on the increase characteristic line L2 of the tire internal temperature Tt (marked with a □) at an outside temperature of 35°C, the increase characteristic line L2 of the tire internal temperature Tt at an outside temperature of 35°C corresponds to the brake lining temperature of 350°C. In this case, the temperature is about 100°C. Therefore, if the tire internal temperature Tt at an outside temperature of 35° C. is, for example, 100° C. or higher, it can be estimated that the brake lining is in an excessively heated state. In other words, the brake lining excessive temperature rise determination threshold Ttss is 100 (° C.).

判定閾値設定部４３ｃでは、このように、外気温検出部４２により検出された車両の周囲の外気温に基づいて、過昇温判定閾値Ｔｔｓｓを設定する。 The tire internal temperature Tt (□ mark) at an outside temperature of 35°C shifts to the high temperature side compared to the tire internal temperature Tt (□ mark) at an outside temperature of 5°C. Here, as shown in FIG. 4, considering that the judgment threshold Ttss shifts linearly according to the outside temperature, if the outside temperature rises by 30 degrees, the judgment threshold Ttss increases by 20 (℃), so the judgment threshold Ttss is , based on the outside temperature of 5°C, add the threshold correction temperature Tc (=(20/30)・Δt(°C)) according to the temperature increase Δt (°C) from the outside temperature of 5°C, and calculate the following formula. It can be set as shown in (A).

The determination threshold value setting unit 43c thus sets the excessive temperature rise determination threshold value Ttss based on the outside temperature around the vehicle detected by the outside temperature detection unit 42.

In addition to the increase in the temperature of the brake lining due to brake operation, factors for increasing the tire internal temperature Tt are also thought to be heat generation in the tire 13 itself due to friction with the road surface and heat generation in the bearing portion 17. Therefore, when the tire internal temperature Tt exceeds the determination threshold Ttss, it cannot be determined that the brake lining is overheated, but there is a possibility that the brake lining is overheated, or the brake mechanism 19 and bearing It is possible to issue a warning that there is a possibility that one of the parts 17 may be in an overheated state.

As shown in FIG. 1, the information output unit 45 includes a tire abnormality information output unit ( When excessive temperature rise of the bearing portion 17 or brake mechanism portion 19 is determined by the tire abnormality information output means) 45a and the tire peripheral high temperature determination portion 43b, an alarm, a warning light display, a warning message, etc. are issued as excessive temperature rise information. An abnormality information output unit (abnormality information output means) 45b.

Since the determination by the tire abnormality determination section 43a and the determination by the tire peripheral high temperature determination section 43b are performed independently of each other, depending on the tire internal temperature Tt, an alarm etc. by the tire abnormality information output section 45a and a warning etc. by the abnormality information output section 45b are performed. Warnings, etc. may also be issued at the same time.

Note that the elements of the tire sensor unit 30 and the abnormality detection unit 40, excluding the outside temperature detection section 42, the tire peripheral high temperature determination section 43b, and the determination threshold setting section 43c, are components of the tire pressure monitoring system (TPMS) 20A. The vehicle abnormality detection device according to the present embodiment is a tire pressure monitoring device (TPMS) 20A in which an outside temperature detection section 42, a tire peripheral high temperature determination section 43b, and a determination threshold setting section 43c are added.
Furthermore, although the rear wheels have been described as an example in FIG. 2, the vehicle abnormality detection device according to the present embodiment is provided for each wheel equipped on the vehicle.

[2. Action and effect]
According to the vehicle abnormality detection device according to the present embodiment, an abnormality due to excessive temperature rise in the bearing portion 17 or the brake mechanism portion 19, which is a vehicle member around the tire 13, is detected using the detection information by the tire sensor unit 30. and issues abnormal information. Therefore, it is possible to prompt the driver to take measures such as using other braking operations such as engine braking in combination, making it possible to prevent brake fade.

In this way, it is possible to detect an abnormality in the tire 13 of the vehicle, the bearing section 17 around the tire 13, or the brake mechanism section 19 and output abnormality information while suppressing an increase in the number of parts, thereby reducing the equipment cost. This also reduces the frequency of physical failures and increases in maintenance costs.
Further, since the determination threshold value for determining an abnormality in the bearing portion 17 or the brake mechanism portion 19 is corrected based on the outside temperature, the accuracy of abnormality determination can be improved.

[3. others]
The configuration of the embodiment described above is an example, and can be modified and implemented as appropriate without departing from the spirit of the present invention.
For example, the values shown in FIGS. 3 and 4 and the above equation (A) are just examples, and the values may vary depending on the characteristics of the sensor, wheel, etc. However, each numerical value in the above formula (A) can be appropriately set by conducting a test or the like in advance and determining each numerical value depending on the characteristics of the sensor, wheel, etc.
Further, in the above embodiment, the operating state of the brake is not considered, but the frequency of operating the brake is calculated from the brake switch information, and it is determined that the frequency of operating the brake is above a certain level and the temperature inside the tire is above the determination threshold. In some cases, it may be determined that the brake mechanism is in an excessively heated state.

1 Vehicle 10 Body 11 Wheel 12 Wheel 12a Outer rim portion of wheel 12 12b Disc portion of wheel 12 12c Inner rim portion of wheel 12 13 Tire 14 Wheel hub 14a Flange portion of wheel hub 14 15a Hub bolt (fastening member)
15b Wheel nut (fastening member)
16 Axle pipe 17 Bearing section 17a, 17b Roller bearing 18 Axle shaft 18a Flange of axle shaft 18 18b Connection bolt 19 Brake mechanism section 20A Tire pressure monitoring device (TPMS)
20 Vehicle abnormality detection device 30 Tire sensor unit (tire sensor)
40 Abnormality detection unit 31 Sensor section (tire condition detection means)
32 Pressure detection unit 33 Temperature detection unit 34 Signal processing unit 35 Storage unit 36 Transmission processing unit 37 Battery 40 Abnormality detection unit 41 Reception processing unit 42 Outside temperature detection unit (outside temperature detection means, outside temperature sensor)
43 Signal processing section 43a Tire abnormality determination section (tire abnormality determination means)
43b Tire peripheral high temperature determination unit (tire peripheral high temperature determination means)
43c Judgment threshold setting unit (judgment threshold setting means)
44 Storage unit 45 Information output unit (information output means)
45a Tire abnormality information output unit (tire abnormality information output means)
45b Abnormality information output unit (abnormality information output means)

Claims (1)

Tire condition detection means installed on a vehicle and arranged on the outer rim of a wheel to which a tire is attached, and detects pressure and temperature inside the tire;
Tire abnormality determining means for determining abnormality in the tire from the pressure and temperature within the tire detected by the tire condition detecting means;
Tire abnormality information output means that outputs tire abnormality information when the tire abnormality determining means determines that the tire is abnormal;
outside temperature detection means for detecting the outside temperature of the vehicle;
determination threshold setting means for setting a determination threshold according to the outside temperature detected by the outside temperature detection means;
When the temperature inside the tire detected by the tire condition detection means exceeds the determination threshold, a bearing section that pivotally supports the wheel or a brake mechanism section disposed inside the wheel is in an excessive temperature state. a tire peripheral area high temperature determination means for determining that there is a high temperature;
An abnormality detection device for a vehicle, comprising: abnormality information output means for generating excessive temperature rise information when excessive temperature rise of the bearing portion or the brake mechanism portion is determined by the tire peripheral high temperature determination means.

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