JP2005088874A - Travelable distance estimation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely estimate travelable distance capable of traveling in a state of puncture of the run-flat tire in a vehicle with wheels having run-flat tires. <P>SOLUTION: The vehicle with wheels 10 having run-flat tires 20 is provided with a device which estimates the travelable distance L capable traveling in the state of puncture of the run-flat tire. The device comprises (a) a tire load state quantity sensor 42 which is mounted to the run-flat tire and detects the tire load state quantity (for example, temperature and strain) of the state quantity expressing the load and (b) an estimation apparatus estimating the travelable distance L based on the detected tire load state quantity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a travelable distance estimating device for estimating a travelable distance in which a runflat tire can travel in a punctured state in a vehicle having wheels equipped with runflat tires. The present invention relates to an improvement in the technology for estimating the distance.

  When a normal tire is forced to run with the air pressure lowered to 0 due to puncture, a large deformation occurs in itself, so it is recommended to stop the vehicle as soon as possible and replace the tire.

  On the other hand, a run flat tire is already known that can travel a sufficient distance to move to a place where the tire can be replaced or repaired safely even in a puncture state.

  And the technique which estimates the driving | running | working distance which the run flat tire can drive | work in a puncture state is already known in the vehicle provided with the wheel with which such a run flat tire was mounted | worn (for example, refer patent document 1). .)

In Patent Document 1, when a puncture occurs in a run-flat tire, the distance that the punctured run-flat tire can travel is estimated based on the travel distance and travel speed of the vehicle after the occurrence.
JP-A-62-87816

  If it becomes possible to accurately estimate the distance that the punctured run-flat tire can travel, it will be clear to the driver the distance that the vehicle can safely travel and when the run-flat tire should be replaced. As a result, the driver can easily drive the vehicle even when puncturing.

  Against such a background, the present inventor has studied a technique for accurately estimating the travelable distance of a punctured run-flat tire, and as a result, in order to improve the estimation accuracy, It has been found that it is important to detect and refer to the state quantity of the flat tire (for example, the temperature of the run-flat tire, the amount of deformation state).

  Based on such knowledge, the present invention has been made to accurately estimate the travelable distance that the runflat tire can travel in a puncture state in a vehicle having wheels equipped with runflat tires. Is.

  The following aspects are obtained by the present invention. Each aspect is divided into sections, each section is given a number, and is described in a form that cites other section numbers as necessary. This is to facilitate understanding of some of the technical features described herein and some of their combinations. The technical features and combinations thereof described herein can be It should not be construed as limited.

Further, describing each section in the form of quoting the numbers of the other sections does not necessarily prevent the technical features described in each section from being separated from the technical features described in the other sections. It should not be construed as meaning, but it should be construed that the technical features described in each section can be appropriately made independent depending on their properties.
(1) A travelable distance estimation device that estimates a travelable distance in which a runflat tire can travel in a punctured state in a vehicle configured such that a wheel on which a runflat tire is mounted is supported by a vehicle body,
A tire load state quantity sensor which is mounted on the run flat tire and detects a tire load state quantity which is a state quantity representing the load of the tire;
A travelable distance estimation device comprising: an estimator that estimates the travelable distance based on the detected tire load state quantity.

  According to the inventor's research, it has been found that the travelable distance that the run-flat tire can travel in the punctured state strongly depends on the state quantity representing the load of the run-flat tire. Specifically, it has been found that it strongly depends on the temperature of the run-flat tire, the amount of deformation state, and the like.

  Therefore, it is possible to accurately estimate the travelable distance of the punctured run-flat tire by referring to the state quantity representing the load of the run-flat tire.

  Based on such knowledge, in the apparatus according to this section, a run load tire is equipped with a tire load state quantity sensor that detects a state quantity representing the load thereof, and the detected tire load state quantity is determined. Based on this, the travelable distance of the punctured run-flat tire is estimated.

  The “runflat tire” in this section should be referred to as, for example, a side wall reinforcing type in which the rigidity of the side fall of the tire is higher than that of a normal tire and the side wall is prevented from being greatly bent even in a puncture state. There is a format.

  As the “runflat tire” in this section, a member having rigidity higher than that of the tire is disposed as a core between the tread of the tire and the rim of the wheel in the tire air chamber. There is also a type that should be referred to as a core type in which the tread and the rim are prevented from approaching each other more than a set distance by the core.

  In this core type, the rigidity of the sidewall of the tire (particularly the longitudinal rigidity) is apparently increased by the core. In this core type, the core does not contact the tire in a state where the tire is normal, but contacts the tire for the first time in the puncture state, thereby acting to suppress the tire from being bent. Thus, in the puncture state, the core acts to apparently improve the rigidity of the tire. Therefore, although the core is separated from the tire when the tire is normal, it is functionally run. It is reasonable to think that it forms part of a flat tire.

  Therefore, in this core type, in the act of attaching the “tire load state quantity sensor” in this section to the run-flat tire, it is attached to the tire in a narrow sense or attached to the core as an element of a broad sense tire. To be included.

  The “puncture state” in this section can be defined as a term meaning a complete puncture state or a term meaning a state indicating a sign of a complete puncture state.

  The “tire load state sensor” in this section is preferably one that directly detects the tire load state quantity, but can be indirectly detected.

Further, the “tire load state quantity sensor” can be attached to a sidewall of a run flat tire, for example. According to this aspect, it is easy to detect the load state amount for a portion of the run flat tire that has a large deformation amount in the puncture state.
(2) The run-flat tire includes a shape deformation suppressing portion that suppresses shape deformation of the run-flat tire during traveling of the vehicle without depending on the air pressure therein.
The travelable distance estimation device according to (1), wherein the tire load state quantity sensor is attached to the shape deformation suppression unit and detects the load state quantity of the shape deformation suppression unit as the tire load state quantity.

  According to this device, the load state quantity of the shape deformation suppressing unit that is a part of the run-flat tire is detected as the tire load state quantity, and the travelable distance is estimated based on the detected tire load state quantity. The

  Therefore, according to this device, it is possible to estimate the travelable distance in consideration of the remaining amount or margin of the suppression capability of the shape deformation suppression unit that is a part of the run-flat tire.

The “shape deformation suppressing portion” in this section is, for example, a side wall reinforcing member in the above-described side wall reinforcing type, and a core in the above core type.
(3) The travelable distance estimation device according to (1) or (2), wherein the tire load state quantity includes a temperature of the run-flat tire.

  The properties of rubber, which is a general material constituting a run-flat tire, are easily affected by heat. Specifically, rubber is more susceptible to deterioration at higher temperatures.

  Therefore, referring to the temperature of the run-flat tire, it becomes easy to accurately estimate the distance that it can travel in the puncture state.

Based on such knowledge, in the apparatus according to this item, the tire load state quantity in the item (1) or (2) is assumed to include the temperature of the run-flat tire.
(4) The travelable distance estimation device according to any one of (1) to (3), wherein the tire load state quantity includes a deformation state quantity of the run-flat tire.

  The greater the amount of deformation of a run-flat tire (for example, the above-described core, etc., including the shape deformation suppressing portion), that is, the deformation in the puncture state from the shape in the non-puncture state, the larger the run flat tire. It can be determined that the tire sag is large, or that the run-flat tire has a short life.

  Accordingly, referring to the deformation state quantity of the run-flat tire, it becomes easy to accurately estimate the travelable distance of the punctured run-flat tire.

  Based on such knowledge, in the apparatus according to this section, the tire load state quantity in any one of the items (1) to (3) includes the deformation state quantity of the run-flat tire.

Examples of the “deformation state amount” in this section include strain of a run-flat tire (for example, a sidewall thereof in particular), a deflection amount (including a deflection angle), a bending amount (including a bending angle), and the like. .
(5) The estimator includes at least one of the detected tire load state quantity, a running speed of the vehicle, a load acting on the run-flat tire, and a state quantity of a road surface on which the vehicle travels. The travelable distance estimating device according to any one of (1) to (4), wherein the travelable distance is estimated based on the travelable distance.

  The travelable distance in the punctured state of the run flat tire depends on, for example, the magnitude and frequency of the force applied from the outside to the run flat tire at the time of puncture or thereafter.

  For example, the higher the traveling speed of the vehicle, the more frequently the run-flat tire is deformed and its load increases, so the travelable distance becomes shorter. Further, as the load acting on the run-flat tire is larger, the deformation amount thereof is increased and the load is increased. In this case as well, the travelable distance is shortened. Further, the more uneven the road surface on which the vehicle travels, the greater the deformation amount of the run-flat tire and the load on the run-flat tire increases. In this case as well, the travelable distance becomes shorter.

  Here, when the tire load state quantity and the travel speed, load, and road surface state quantity are compared with each other in terms of their properties, the tire load state quantity is the run-flat tire (including the above-described shape deformation suppressing unit) itself. , While it can be categorized into parameters representing the mechanical characteristics at each time of the puncture state, such as the traveling speed, the environment where the run-flat tire is placed at each detection time of the tire load state amount, It can be classified into parameters representing the environment in which the run-flat tire is expected to be placed in the future of each detection time.

  Based on the knowledge explained above, in the device according to this section, among the state quantity representing the load of the run-flat tire, the running speed of the vehicle, the load acting on the run-flat tire, and the state quantity of the road surface on which the vehicle runs The travelable distance is estimated based on at least one of the following.

  The “vehicle traveling speed” in this section can be defined as the rotational speed of the run-flat tire. The “load acting on the run-flat tire” in this section includes, for example, a load acting on the run-flat tire in the width direction thereof, a load acting on the height direction thereof, that is, a contact load.

  Here, “the load acting on the run-flat tire in the width direction thereof” can be obtained directly by, for example, detecting the lateral force acting on the run-flat tire, or detecting the lateral acceleration of the wheel or the vehicle body. It is possible to acquire indirectly.

  Further, the “contact load” can be directly acquired by detecting the vertical force acting on the run-flat tire, or indirectly detected by detecting the vertical acceleration of the wheel or the vehicle body.

Examples of the “road surface state quantity” in this section include a road surface friction coefficient and a road surface unevenness degree.
(6) The estimator determines the travelable distance based on the detected tire load state quantity, and the determined travelable distance is determined based on the travel speed of the vehicle and the load acting on the run-flat tire. The travelable distance estimation device according to any one of (1) to (4), wherein the travelable distance is corrected based on at least one of a state quantity of a road surface on which the vehicle travels.

According to this apparatus, it is possible to realize basically the same operation effect according to basically the same principle as the apparatus according to the above item (5).
(7) The tire load state quantity includes a deflection amount of the run flat tire, the travelable distance estimation device further includes a tire air pressure sensor that detects an air pressure of the run flat tire, and the estimator includes: Based on the amount of deflection detected by the tire load state quantity sensor and the air pressure detected by the tire air pressure sensor, the ground contact load of the run flat tire is estimated as a load acting on the run flat tire, and the estimation The travelable distance estimation device according to any one of (1) to (6), wherein the travelable distance is estimated based on the detected ground contact load and the detected tire load state quantity.

  A certain relationship is established among the deflection amount of the run-flat tire, the air pressure, and the contact load. Therefore, if the deflection amount and the air pressure can be detected, the contact load can be estimated.

  On the other hand, the greater the ground contact load, the greater the load on the run-flat tire and the shorter the travelable distance.

Based on such knowledge, in the apparatus according to this item, the ground load of the run flat tire is estimated based on the deflection amount and the air pressure of the run flat tire, and the estimated ground load and the tire load state are estimated. Based on the quantity, the travelable distance of the punctured run-flat tire is estimated.
(8) The estimator is attached to the vehicle body, and the travelable distance estimation device further includes:
A transmitter mounted on the wheel and transmitting a signal representing a tire load state quantity detected by the tire load state quantity sensor;
A receiver mounted on the vehicle body and receiving a signal transmitted from the transmitter, wherein the estimator is capable of traveling based on a tire load state quantity represented by a signal supplied from the receiver. The travelable distance estimation apparatus according to any one of (1) to (7), wherein the distance is estimated.

According to this device, it is possible to estimate the travelable distance of the punctured run-flat tire on the vehicle body side while remotely monitoring the tire load state quantity on the vehicle body side.
(9) The wheel includes the run-flat tire and the wheel, and when the run-flat tire is attached to the wheel, an annular tire chamber is formed in the wheel.
The shape deformation suppression unit is a core disposed in the tire chamber in a posture that partitions the tire chamber into a tread side near the tread of the run-flat tire and a wheel side near the wheel, and the tread Including one that suppresses the tread from approaching the wheel by selectively contacting
The travelable distance estimation device according to any one of (1) to (8), wherein the tire load state quantity sensor is attached to a core of the tire load state quantity sensor on the wheel side.

  When the run-flat tire is a core type whose rigidity is reinforced by using a core disposed in the tire chamber, the tire chamber is partitioned into a tire side and a wheel side by the core. Accordingly, there are a tread side position and a wheel side position as two candidate positions for mounting the tire load state quantity sensor on the core.

  When these two candidate positions are compared with each other with respect to the possibility that the tire load state sensor contacts the tire, when the tire load state sensor is attached to the core on the wheel side, for example, in (a) A wheel assembly process to be inserted into the tire in order to mount the child on the tire; (b) the tire pressure tends to bend because the tire air pressure has dropped slightly, and therefore the tire steadily approaches the wheel. Or (c) a vehicle running state in which the tire is repeatedly approaching the wheel because the vehicle is running on a rough road such as an uneven road although the tire air pressure is not so low. There is no possibility that the tire load state sensor contacts the tire, or the tire load state sensor is attached to the core on the tire side. Less than if you.

  Based on such knowledge, in the apparatus according to this item, when the run-flat tire is a core type and the tire load state quantity sensor is attached to the core, the tire load state quantity sensor Is attached to the core on the wheel side.

Therefore, according to this device, it is easy to reduce the possibility that the tire load state sensor contacts the tire and, for example, it is easy to improve the assembly workability of the wheel and the reliability of the device. It becomes.
(10) The core is connected to the wheel and a mounting portion that is mounted on the wheel. The tread is attached to the wheel by selectively contacting the tread and supporting the tread from the inside. And a support part that suppresses approaching,
The travelable distance estimating device according to (9), wherein the tire load state quantity sensor is mounted on at least one of the mounting portion and the support portion on the wheel side.
(11) The tire load state quantity sensor is attached to a portion of the core that responds to a change in the load more sensitively than other portions in mechanical properties thereof (9) or (10) The travelable distance estimation apparatus according to the item.

According to this apparatus, the tire load state quantity sensor is attached to a portion of the core that is less sensitive to the mechanical properties of the core than other portions and responds to fluctuations in the load. And it becomes easy to detect the load applied to the core with high accuracy and high sensitivity.
(12) A tire information acquisition device that acquires tire information related to travel of the run-flat tire in a vehicle in which a wheel on which a run-flat tire reinforced by a core is mounted is supported by a vehicle body,
A tire load state sensor that is mounted on the core and detects a tire load state amount that is a state amount representing the load thereof;
A tire information acquisition device comprising: an acquisition unit configured to acquire the tire information based on the detected tire load state quantity.

  According to this device, by utilizing the property that the mechanical property of the core of the run-flat tire changes according to the load on the run-flat tire, the run-flat tire core is based on the detected value of the load on the core. It becomes possible to acquire tire information relating to the running of a flat tire.

  For example, when the vehicle travels in a puncture state of a core type run-flat tire, a larger load than usual is applied to the tire, the core, and the wheel among the wheels. Based on the magnitude and fluctuation tendency of the load, it is possible to estimate the distance that the run-flat tire can travel in a puncture state, and such information is an example of “tire information” in this section.

  Even when the vehicle travels in a state where the core-type run-flat tire is not punctured, a larger load than usual may be applied to the core. For example, because the vehicle is driving on rough roads such as gravel roads, uneven roads, etc., or because run flat tires have bumps such as curbs, steps, etc. May be impacted from the tire to the core.

  The core is a part having higher rigidity than the tire. Such a core is attached to a wheel, and the wheel is attached to a component on the vehicle body side such as a suspension. Therefore, when a load is applied to the core in an impact, the load may be applied to the wheel and the suspension in an impact. In any part, when a load is applied impactively, strength durability may be reduced or deformation that does not recover may occur.

  Such a load may be remarkably generated as a change in tire air pressure. Therefore, it is sufficient that the tire air pressure sensor can detect the load without omission, but such a load is not always expected. That is, even when a large impact force is applied to the core, the tire air pressure level may not change significantly as detected by the air pressure sensor. The fact that a large impact force is applied to the core cannot be detected by the tire pressure sensor.

On the other hand, according to the apparatus according to this section, the tire load state sensor mounted on the core can directly detect the load on the core, and thus the wheel including the core and the wheel. And / or it becomes easy to detect the overload to the vehicle body including the suspension without leakage and at an early stage.
(13) The tire information acquisition device according to (12), wherein the tire information includes a travelable distance in which the run-flat tire can travel in a punctured state.
(14) The tire load state quantity sensor includes a core load related quantity sensor that detects a physical quantity related to the core load input to the core from the road surface while the vehicle is running,
The tire information acquisition device according to (12) or (13), wherein the tire information includes core load related information related to the core load.

An example of the “core load related quantity sensor” in this apparatus is a strain gauge that detects strain generated in the core according to the magnitude of the input load.
(15) The tire information acquisition device according to (14), wherein the core load related information includes at least one of a magnitude of the core load and a change frequency thereof.

  In order to predict the strength durability of wheels and vehicle bodies that receive loads from the road surface and the presence or absence of deformation that does not recover, it is sufficient to consider the magnitude indicated at the moment when the load acting on the core is present, or within a certain period of time in the past In some cases, it is sufficient to consider the change frequency of the load (for example, the number of times the magnitude of the load exceeds a threshold value within a certain period of time), or to consider both of them may be important in ensuring accuracy. In other words, it may be important to consider the instantaneous value, the trend, and the instantaneous value and the trend for the load acting on the core. .

Based on such knowledge, in the apparatus according to this section, tire information is acquired based on at least one of the magnitude of the core load and the change frequency thereof.
(16) The core load related information includes the magnitude of the core load when the run flat tire is not punctured and the change frequency of the core load when the run flat tire is not punctured. The tire information acquisition device according to item (15), including at least one of them.

  According to this device, tire information can be acquired based on the detected value of the load input to the run-flat tire from the road surface when the run-flat tire is not punctured. For example, due to the impact load from the road surface, whether or not the strength durability may have been reduced in the core, wheel, or part of the vehicle body related to the wheel, or there is a possibility that deformation that has not been restored has occurred. It is possible to acquire tire information regarding whether or not there is.

The “change frequency of the core load” in this section is expressed, for example, as the number of times that the size of the core load exceeds a threshold value within a certain time, or the strength of the frequency component of the time variation of the core load is substantially It can be expressed as the frequency of the maximum (for example, the frequency component whose power spectrum is substantially maximum).
(17) The acquisition unit determines whether or not it is necessary to issue a warning to the driver of the vehicle based on the acquired tire information, and if necessary, a warning that issues the warning. The tire information acquisition device according to any one of (12) to (16), including means.
(18) The core is connected to the wheel and a mounting portion that is mounted on the wheel, and selectively contacts the tread to support the tread from the inside, whereby the tread is attached to the wheel. And a support part that suppresses approaching,
The tire information acquisition device according to any one of (12) to (17), wherein the tire load state quantity sensor is mounted on at least one of the mounting portion and the support portion on the wheel side.
(19) The tire load state quantity sensor is mounted on a part of the core that responds to the load variation more sensitively than the other parts of its mechanical properties (12) to (18). The tire information acquisition device according to any one of the items.

  According to this apparatus, the tire load state quantity sensor is attached to a portion of the core that is less sensitive to the mechanical properties of the core than other portions and responds to fluctuations in the load. And it becomes easy to detect the load applied to the core with high accuracy and high sensitivity.

  Hereinafter, some of more specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 conceptually shows a travelable distance estimation device (hereinafter simply referred to as “estimation device”) according to the first embodiment of the present invention mounted on a vehicle. The vehicle includes left and right front wheels 10 and 10 and left and right rear wheels 10 and 10. Each wheel 10 is configured by attaching a rubber tire 20 filled with air pressure under pressure to a metal wheel 22 as partially shown in a sectional view in FIG. The tire 20 is configured to include a tread 30 and a sidewall 32.

The tire 20 of each wheel 10 is a run flat tire that can travel to some extent even in a puncture state. Since the tire 20 is the above-described sidewall reinforcement type, as shown in FIG. 2, the inner portion of the sidewall 32 is a reinforcement portion 34 reinforced by rubber having higher hardness than other portions. Yes. However, the present invention can be implemented by changing the tire 20 to a core-type run-flat tire. As shown in FIG. 2, each wheel 10 includes a tire-side detection unit 40 and a tire load state quantity sensor 42. And are attached.

  Specifically, the tire side detection unit 40 is attached to an air valve 46 attached to the wheel 22 and includes a tire pressure sensor 50, a computer 52, and a transceiver 54 as shown in FIG.

  The tire air pressure sensor 50 is a sensor that directly detects the air pressure of the tire 20. On the other hand, the transceiver 54 has a function of wirelessly transmitting a signal representing the air pressure detected by the tire air pressure sensor 50 and a function of wirelessly receiving an external signal. The computer 52 is connected to the tire pressure sensor 50 and the transceiver 54, and performs signal processing necessary for them.

  As shown in FIG. 2, the tire load state quantity sensor 42 is attached to the tire 20, specifically, embedded in the reinforcing portion 34. As shown in FIG. 3, the tire load state quantity sensor 42 includes a tire temperature sensor 60 that detects the temperature of the tire 20 (particularly the temperature of the sidewall 32), and the amount of deflection of the tire 20 (particularly the amount of deflection of the sidewall 32). And a tire deflection sensor 62 for detecting the above.

  The sensors 60 and 62 are electrically connected to the computer 52 of the tire-side detection unit 40 by wires (not shown), and thus connected to the transceiver 54. Therefore, the detection results of these sensors 60 and 62 are transmitted to the outside wirelessly through the transceiver 54.

  However, by using a transceiver (at least a transmitter) dedicated to the tire load state quantity sensor 42, the detection result of the tire load state quantity sensor 42 is transmitted wirelessly without going through the transceiver 54. Is possible.

  As shown in FIGS. 1 and 3, the estimation apparatus further includes a signal processing device 70. As shown in FIG. 3, the signal processing device 70 is configured to include an electronic control unit (hereinafter referred to as “ECU”) 74 having a computer 72 as a main component. As is well known, the computer 72 includes a CPU 80, a ROM 82, and a RAM 84 connected to each other via a bus (not shown).

  A plurality of sensors are connected to the ECU 74. As these sensors, there are a vehicle speed sensor 90 that detects the vehicle speed, which is the traveling speed of the vehicle, a lateral G sensor 92 that detects the lateral acceleration of the vehicle body, and a vertical G sensor 94 that detects the vertical acceleration of the vehicle body.

  The vehicle speed sensor 90 may be a system that estimates the vehicle speed comprehensively based on output signals of a plurality of wheel speed sensors (not shown) that are respectively provided on the plurality of wheels 10 and detect the wheel speed. The lateral G sensor 92 can be used to estimate the lateral force of the tire 20, and the vertical G sensor 94 can be used to estimate the degree of unevenness of the road surface.

  Although it is possible to estimate the travelable distance L using the lateral force and / or the unevenness of the road surface, in the present embodiment, the travelable distance L is estimated without considering them. ing.

  A transceiver 96 is also connected to the ECU 74. As shown in FIG. 1, the transceiver 96 includes an antenna 100 in proximity to each wheel 10, and transmits and receives wirelessly to and from the transceiver 54 of each wheel 10.

  As shown in FIG. 3, the display unit 110 is also connected to the ECU 74. The indicator 110 is configured to puncture the tire 20 based on the air pressure P detected by the tire-side detection unit 40 and the output signal of the tire load state sensor 42 according to a command from the ECU 74 and estimated according to an algorithm described later. The travelable distance L that can be traveled in the state is displayed in association with each wheel 10. In the present embodiment, the display device 110 displays such information as numerical values.

  FIG. 4 shows an example of display by the display device 110. In this display example, an image representatively representing the vehicle in a plan view is displayed on the screen of the display 110, and a part of the four tires 20 in the vehicle image is distinguished from the other tires 20. It is displayed. Such distinction display is performed in order to identify and display the tire 20 that has a high possibility of being punctured. Further, on the screen of the display 110, a travelable distance L that the tire 20 can travel in a punctured state is displayed in association with the tire 20 that is likely to be punctured.

  FIG. 5 conceptually shows the contents of a tire-side signal processing program repeatedly executed by the computer 52 of the tire-side detection unit 40 in a flowchart.

  At each execution of the tire-side signal processing program, it is first determined whether or not a transmission request has been issued in step S1 (hereinafter simply represented by “S1”. The same applies to other steps). .

  For example, in the case where the computer 52 is designed to transmit a signal from the tire side in response to a transmission request received from the signal processing device 70 on the vehicle body side, this S1 receives a transmission request from the signal processing device 70. It is determined whether or not it has been received. On the other hand, when the computer 52 is designed to spontaneously transmit a signal from the tire side every time a predetermined transmission timing arrives, this S1 determines whether or not the transmission timing has arrived. I do.

  In any case, if it is assumed that a transmission request has not been issued this time, the determination in S1 is NO, and one execution of the tire side signal processing program is immediately terminated.

  On the other hand, if it is assumed that a transmission request is issued this time, the determination in S1 is YES, and the process proceeds to S2.

  In S2, the tire pressure sensor 50 detects the tire pressure P. Subsequently, in S3, the tire temperature θ is detected by the tire temperature sensor 60. Thereafter, in S4, the tire deflection amount sensor 62 detects the tire deflection amount d.

  Subsequently, in S5, the size and brand of the tire 20 mounted on the wheel 10 on which the computer 52 is mounted are read from the ROM (not shown) of the computer 52.

  Thereafter, in S6, signals representing the detected tire air pressure P, tire temperature θ, and tire deflection d are transmitted to the signal processing device 70 in association with the current wheel 10. In S <b> 6, signals representing the read tire size and tire brand are also transmitted to the signal processing device 70 in association with the current wheel 10.

  This completes one execution of the tire-side signal processing program.

  In FIG. 6, the contents of the vehicle body side signal processing program stored in the ROM 82 of the computer 72 of the signal processing device 70 and executed by the CPU 80 are conceptually represented by a flowchart.

  This vehicle body side signal processing program is also repeatedly executed. When executing each time, first, in S31, it is determined whether or not a signal is received from the tire-side detection unit 40. If it is assumed that no signal has been received this time, the determination is no, and one execution of the vehicle body side signal processing program immediately ends.

  On the other hand, if it is assumed that a signal is received from the tire side detection unit 40 this time, the determination in S31 is YES, and the process proceeds to S32.

  In S <b> 32, it is determined whether there is a punctured tire 20 among the plurality of tires 20 based on the signals received for the plurality of wheels 10 and representing the tire air pressure P. If it is assumed that there is no punctured tire 20 this time, the determination is no, and S33 to S37 are skipped, and then the process proceeds to S38.

  In this case, in S38, the signal representing the tire air pressure P of each wheel 10 received from each tire-side detection unit 40 is demodulated into data representing the tire air pressure P, and then associated with each wheel 10 in FIG. As illustrated, the tire pressure P is numerically displayed on the screen of the display 110.

  On the other hand, this time, if it is assumed that there is a punctured tire 20, the determination in S32 is YES, and the process proceeds to S33.

  In S33, for each tire 20 that is punctured, a tire-side detection unit is selected from a plurality of correspondence relationships stored in the ROM 82 for reference for estimating the ground load F and the travelable distance L. A correspondence that matches the tire size and tire brand received from 40 is selected.

  As a result, for each tire 20 that is punctured, in order to estimate the first correspondence relationship for estimating the contact load F and the travelable distance L that are suitable for both the tire size and the tire brand. The second correspondence relationship is selected. The first correspondence relationship is a known correspondence relationship established between the tire deflection amount d, the tire air pressure P, and the ground load F, and the second correspondence relationship includes the tire temperature θ, the vehicle speed V, and the ground load F. This is a known correspondence relationship established with the travelable distance L. Any correspondence can be expressed by, for example, an expression, a map, or a table.

  Subsequently, the vehicle speed V is detected by the vehicle speed sensor 90 in S34. Thereafter, in S35, for each tire 20 that is punctured, the contact load F according to the tire deflection amount d and the tire air pressure P received from the tire side detection unit 40 and according to the selected first correspondence relationship. Is determined.

  Here, the tire deflection amount d and the tire air pressure P used to determine the contact load F mean those received from the tire-side detection unit 40 and stored in the RAM 84 prior to the puncture of each tire 20. Yes. In S35, the contact load F is determined for each tire according to the tire deflection amount d and the tire air pressure P acquired before puncture and according to the first correspondence selected in S33 after puncture. As a result, the ground load F is estimated. FIG. 7 is a graph showing an example of the first correspondence relationship.

  Thereafter, in S36 of FIG. 6, for each tire 20 that is punctured, according to the detected vehicle speed V, the estimated ground load F, and the tire temperature θ received from the tire-side detection unit 40, and According to the selected second correspondence relationship, a travelable distance L that allows the tire 20 to travel in a punctured state is determined. As a result, the travelable distance L is estimated.

In the present embodiment, the second correspondence relationship is
L = K1 (V) · K2 (F) · f (θ)
It is expressed by the following formula.

  Here, “f (θ)” is a function of the tire temperature θ and is used to calculate a provisional value (value before correction) of the travelable distance L. An example of the characteristic of this function f (θ) is represented by a graph in FIG. In this example, the higher the tire temperature θ, the shorter the travelable distance L.

  “K1 (V)” is a first correction coefficient depending on the vehicle speed V. An example of the characteristic of the first correction coefficient K1 is represented by a graph in FIG. In this example, when the vehicle speed V is equal to the reference vehicle speed V0, the first correction coefficient K1 becomes 1, and when the vehicle speed V increases from the reference vehicle speed V0, the first correction coefficient K1 decreases from 1, and conversely, the vehicle speed V becomes the reference speed. When the vehicle speed decreases from V0, the first correction coefficient K1 increases from 1.

  “K2 (F)” is a second correction coefficient depending on the ground load F. An example of the characteristic of the second correction coefficient K2 is represented by a graph in FIG. In this example, as in the example shown in FIG. 5B, when the ground load F is equal to the reference ground load F0, the second correction coefficient K2 becomes 1, and when the ground load F increases from the reference ground load F0, 2 When the correction coefficient K2 decreases from 1, and the ground contact load F decreases from the reference ground load F0, the second correction coefficient K2 increases from 1.

  When the travelable distance L is estimated as described above, the estimated travelable distance L is then associated with each punctured tire 20 in S37 of FIG. 6 as illustrated in FIG. It is displayed on the screen of the display device 110.

  Subsequently, in S38 of FIG. 6, the tire air pressure P received from the tire side detection unit 40 is displayed as a numerical value on the screen of the display device 110 in association with each tire 20.

  Thus, one execution of the vehicle body side signal processing program is completed.

  In FIG. 9, three relationships between the tire temperature θ and the travelable distance L are represented by an uppermost graph, a center graph, and a lowermost graph, respectively.

  The uppermost graph shows that, when puncture occurs when the tire temperature θ is lower than the other two graphs, the travelable distance L subsequently decreases with the tire temperature θ.

  In the center graph, the tire temperature θ is lower than the top graph, but when a puncture occurs when the temperature is higher than the bottom graph, the cruising distance L subsequently decreases with the tire temperature θ. Represents that.

  The lowermost graph shows that when puncture occurs when the tire temperature θ is higher than the other two graphs, the travelable distance L subsequently decreases with the tire temperature θ.

  Each of these graphs shifts in such a direction that the travelable distance L decreases as the vehicle speed V increases, and similarly, as the ground load F increases, the travelable distance L decreases.

  That is, FIG. 9 is a graph showing the property that the travelable distance L depends on the tire temperature θ (or the tire deflection amount d), the vehicle speed V, and the ground load F.

  As is clear from the above description, in this embodiment, the ECU 74 constitutes an example of the “estimator” in any one of the above items (1) to (7), and the reinforcing portion 34 is in the above item (2). An example of the “shape deformation suppression unit” is configured.

  In addition, in this embodiment, as shown in FIG. 4, when a certain tire 20 is punctured, it is assumed that the vehicle continues to travel at the same vehicle speed V as that vehicle speed V for that tire 20. In addition, the travelable distance L is estimated and displayed.

  On the other hand, for example, as shown in FIG. 10, for the punctured tire 20, the travelable distance L (and / or travelable time) is estimated and displayed in association with each possible vehicle speed V in the future. It is possible to carry out the invention.

  According to this aspect, since the vehicle speed V suitable for the distance that the driver wants to travel after the puncture is quickly determined after the puncture, the driver can easily select the vehicle speed V suitable for the desired travel distance. .

  In addition, in the example shown in FIG. 2, the tire 20 is a sidewall reinforcing type. For example, as described above, the tire 20 is a core type, and the tire deflection sensor 62 is a core. It is possible to change this embodiment so that it may be attached to. In this modified example, the ECU 74 constitutes an example of the “acquisition device” in the item (8), and the tire deflection amount sensor 62 constitutes an example of the “tire load state amount sensor” in the same term.

  Next, a second embodiment of the present invention will be described. However, since this embodiment has elements in common with the first embodiment, the common elements are cited using the same reference numerals or names, and detailed description is omitted, and only different elements are cited. This will be described in detail.

  In FIG. 11, one wheel 10 out of four wheels 10 respectively mounted on the front, rear, left and right of a vehicle on which a tire information acquisition device (hereinafter simply referred to as “acquisition device”) according to the present embodiment is mounted. Is typically shown in a partial cross-sectional view. The wheel 10 is configured by mounting a tire 20 on a wheel 22 as in the first embodiment.

  The tire 20 is configured to include a tread 30 and a pair of sidewalls 32 and 32. The wheel 22 is configured to include a rim 150 that faces the tread 30 in the radial direction of the tire 20. The tire-side detection unit 40 is disposed in the vicinity of the surface of the rim 150 that faces the tread 30, and the tire-side detection unit 40 is attached to an air valve 46 that is attached to the rim 150. As shown in FIG. 12, the tire-side detection unit 40 is configured to include a tire air pressure sensor 50, a computer 52, and a transceiver 54, as in the first embodiment.

  As shown in FIG. 11, the tire chamber 152 is formed in the tire 20 by the tire 20 being in close contact with the rim 150 of the wheel 22. A core 160 is disposed in the tire chamber 152. That is, in the present embodiment, the tire 20 is configured as a core type run-flat tire.

  As shown in FIG. 11, the core 160 includes a pair of mounting portions 162 and 162 that are mounted on the rim 150 at two positions that are separated from each other in the axial direction of the tire 20. These mounting parts 162 and 162 are both made of rubber. The core 160 further includes a support portion 164 supported at both ends by the mounting portions 162 and 162. The support portion 164 is made of metal.

  When the height of the air pressure P of the tire 20 is normal, the support portion 164 does not contact the tread 30 unless the vehicle travels on a rough road or rides on a protrusion. However, when the air pressure P is lower than the normal pressure, the support portion 164 comes into contact with the tread 30 more easily than when the air pressure P is equal to the normal pressure, and the contact causes the tread 30 to first contact the support portion 164. To further approach the wheel 22 is mechanically suppressed. Accordingly, the support portion 164 functions to apparently increase the rigidity of the tire 20 by supporting the tread 30 in a contact state.

  As shown in FIG. 11, a tire load state quantity sensor 170 is attached to the core 160. By arranging the core 160 in the tire chamber 152, the space in the tire chamber 152 is partitioned into a tread side close to the tread 30 and a wheel side close to the wheel 22. The tire load state quantity sensor 170 is attached to the core 160 on the wheel side. As a result, the tire load state quantity sensor 170 is prevented from contacting the tire 20 by the core 160 functioning as a partition wall.

  As shown in FIG. 12, the tire load state quantity sensor 170 is configured mainly with a strain gauge 172. As shown in FIG. 11, the strain gauge 172 is provided in a high-sensitivity portion of the core 160 where distortion is generated with high sensitivity to an external force acting on the core 160 from the tread 30 in a contact state with the tread 30. It is installed. The high-sensitivity part is not a mounting part 162 but a part of the support part 164, for example. The high-sensitivity portion is, for example, in the vicinity of both end portions of the support portion 164 and is a connection portion with each mounting portion 162. In the connecting portion, a sufficiently large bending moment is generated by the external force, and accordingly, a sufficiently large strain is also generated.

  The strain gauge 172 is an example of a sensor that electrically detects a strain generated in a portion where the strain gauge 172 is attached to the portion where the strain gauge 172 is attached. On the other hand, a known relationship is established between the load acting on the object and the strain generated on the object due to the load. Therefore, the strain gauge 172 can eventually be used as a sensor for detecting a load acting on the support portion 162 from the tread 30 and the road surface through the strain generated in the support portion 162 as a medium.

  As shown in FIG. 11, in the present embodiment, since the tire side detection unit 40 and the tire load state quantity sensor 170 are arranged separately from each other, the tire side detection unit 40 and the tire load state quantity sensor 170 are arranged. Are electrically connected to each other by a wire 180 as a medium for transmitting an electrical signal.

  FIG. 13 conceptually shows the contents of a tire side signal processing program repeatedly executed by the computer 52 of the tire side detection unit 40 in a flowchart. Hereinafter, the tire-side signal processing program will be described, but steps common to the tire-side signal processing program shown in FIG. 5 will be briefly described.

  When the tire-side signal processing program is executed each time, first, in S31, it is determined whether or not a transmission request has been issued in the same manner as in S1. If it is assumed that a transmission request has not been issued this time, the determination in S31 is NO, and one execution of the tire side signal processing program immediately ends. On the other hand, if it is assumed that a transmission request has been issued this time, the determination in S31 is YES, and the process proceeds to S32.

  In S32, the tire air pressure P is detected by the tire air pressure sensor 50. Subsequently, in S33, the core load W acting on the core 160 is detected based on the output signal from the strain sensor 172.

  Thereafter, the change frequency frq of the core load W is recorded in the RAM 84 in S34. The change frequency frq is defined as, for example, the number of core loads W detected in the past certain time that exceed a predetermined first threshold value Wth1.

  Subsequently, in S35, signals representing the detected tire air pressure P, the magnitude of the core load W, and the change frequency frq are respectively transmitted to the current wheel 10 (each tire-side signal processing program of the four wheels 10 is executed). Is transmitted to the signal processing device 70 in association with it. In S35, the tire-side signal processing program is designed so that signals representing the tire size and tire brand of the current wheel 10 are also transmitted to the signal processing device 70 in association with the current wheel 10. Is possible.

  This completes one execution of the tire-side signal processing program.

  FIG. 14 conceptually shows the contents of a vehicle body side signal processing program stored in the ROM 82 of the computer 72 of the signal processing device 70 and executed by the CPU 80 in a flowchart. Hereinafter, the vehicle body side signal processing program will be described, but steps common to the vehicle body side signal processing program shown in FIG. 6 will be briefly described.

  The vehicle body side signal processing program is repeatedly executed sequentially for the four wheels 10. When the vehicle body side signal processing program is executed for the current wheel 10 of the four wheels 10, first, in S71, a signal is received from the tire side detection unit 40 provided on the current wheel 10. It is determined whether or not. If it is assumed that no signal has been received this time, the determination is no, and one execution of the vehicle body side signal processing program immediately ends. On the other hand, if it is assumed that a signal is received from the tire side detection unit 40 provided on the current wheel 10 this time, the determination in S71 is YES, and the process proceeds to S72.

  In S72, it is determined whether or not the tire 20 of the current wheel 10 is punctured based on the signal received for the current wheel 10 and representing the tire air pressure P. If it is assumed that the vehicle is punctured this time, the determination is YES, and in S73, the current wheel 10 travels in a punctured state based on the signal received for the current wheel 10 that represents the core load W. The possible travel distance L is estimated.

  In S73, for example, in the puncture state, attention is paid to the fact that the core load W corresponds to the above-described ground load F, and by utilizing the relationship that the travelable distance L is shorter as the ground load F is larger. The travelable distance L is estimated. In S73, for example, in order to improve the estimation accuracy of the travelable distance L, the vehicle can travel in consideration of the tire air pressure P, the tire temperature θ, or the vehicle speed V, as in the first embodiment. It is possible to estimate the distance L.

  When the travelable distance L is estimated as described above, in S74, the estimated travelable distance L is associated with each punctured tire 20 as shown in FIG. Displayed on the screen.

  Subsequently, in S75 of FIG. 14, the tire air pressure P received from the tire side detection unit 40 is displayed as a numerical value on the screen of the display device 110 in association with each tire 20. Thereafter, in S76, it is determined whether or not the detected value of the tire air pressure P is lower than the threshold value Pth. If it is assumed that it is low this time, the determination is YES, and in S77, a message indicating that the vehicle is currently running at a low pressure where the tire pressure P of the wheel 10 is lower than the normal pressure, or The driver is warned when the indicator is activated on the display 110. On the other hand, if it is assumed that the detected value of the tire air pressure P is not lower than the threshold value Pth this time, the determination in S76 is NO and S77 is skipped.

  In any case, one execution of the vehicle body side signal processing program is completed.

  As described above, the case where the wheel 10 is punctured has been described above. However, if the wheel 10 is not punctured, the determination in S72 is NO and the process proceeds to S78.

  In S78, it is determined whether the core load W detected for the current wheel 10 is greater than the first threshold value Wth1. If it is assumed that it is not large this time, the determination is no and the process immediately proceeds to S75.

  On the other hand, this time, if it is assumed that the core load W is greater than the first threshold value Wth1, the determination in S78 is YES, and in S79, this core load W is greater than the first threshold value Wth1. Thus, it is determined whether or not it is larger than a predetermined second threshold value Wth2. This time, if it is assumed that it is greater than the second threshold value Wth2, the determination in S79 is YES, and in S80, a message or indicator for recommending the vehicle to the driver is activated on the display 110. The driver is warned.

  That is, when the input load to the core 160 is larger than the second threshold value Wth2, even if the heavy load input to the core 160, the wheel 22 and the suspension (not shown) is only sudden, Since there is a possibility that the strength durability of the core 160, the wheel 22 and the suspension has deteriorated or has not been restored, vehicle inspection (for example, the core 160, the core 160, The driver is informed that the wheel 22 and the suspension need to be inspected for damage such as cracks and deformation. Thereafter, the process proceeds to S75.

  On the other hand, if it is assumed that the core load W is greater than the first threshold value Wth1 but not greater than the second threshold value Wth2 this time, the determination in S78 is YES, and the determination in S79 is NO. The process proceeds to S81.

  In S81, it is determined whether or not the change frequency frq recorded in the RAM 84 for the current wheel 10 is greater than a predetermined threshold frqth. If it is assumed that the vehicle is not large this time, the determination is YES, and it is desirable that the driver refrains from low-pressure traveling in which the vehicle travels in a state where the tire air pressure P of the wheel 10 is lower than the normal pressure in S82. A message or indicator is activated on the display 110 to alert the driver. That is, if the low-pressure running is performed, the strength durability of the core 160, the wheel 22 or the suspension may be lowered, so that the driver is informed that the low-pressure running is not appropriate. Thereafter, the process proceeds to S75.

  Thus, one execution of the vehicle body side signal processing program is completed.

  In addition, in this embodiment, the signal processing / transmission / reception for the tire pressure sensor 50 and the signal processing / transmission / reception for the tire load state quantity sensor 170 are a set of the computer 52 and the transceiver 54 in this embodiment. Therefore, the signal processing / transmission / reception for the two types of sensors 50 and 170 is performed by the combination of two sets of the computer and the transceiver, respectively. Reduction can be easily achieved.

  Next, a third embodiment of the present invention will be described. However, since the present embodiment has elements common to the second embodiment, the common elements are cited using the same reference numerals or names, and detailed description thereof is omitted, and only different elements are cited. This will be described in detail.

  In the second embodiment, a tire air pressure sensor 50 and a tire load state quantity sensor 170 are mounted on each wheel 10, and the tire air pressure P and the core load W are detected and transmitted to the signal processing device 70 on the vehicle body side. The On the other hand, in the present embodiment, only the tire load state quantity sensor 170 is attached to each wheel 10, and only the core load W is detected and transmitted to the signal processing device 70 on the vehicle body side.

  Furthermore, in the present embodiment, based on the magnitude of the core load W and the change frequency frq, an impact load larger than usual is input to the core 160 and the wheel 22 at least when the tire 20 is not punctured. It is determined whether or not the strength durability is reduced due to this, and if so, a warning is given to the driver. The signal processing for the warning is performed by, for example, executing steps corresponding to S78 to S82 in FIG.

  As shown in FIG. 15, in the tire information acquisition device according to the present embodiment, the tire side detection unit 200 is mounted (embedded) in the mounting portion 162 of the core 160. As shown in FIG. 16, the tire side detection unit 200 is configured as a chip (or ID chip) in which a computer 52, a transceiver 54, and a tire load state quantity sensor 170 are built. The tire side detection unit 200 includes a tire load state quantity sensor 170 instead of the tire air pressure sensor 50 with respect to the tire side detection unit 40 in the second embodiment.

  That is, in the present embodiment, as a result of the tire load state quantity sensor 170, the computer 52, and the transceiver 54 being arranged integrally with each other, wires that electrically connect them to each other are not necessary. This is different from the second embodiment in which the tire load state quantity sensor 170 and the computer and the transmitter / receiver 54 are arranged separately from each other, and as a result, a wire 180 that electrically connects them is necessary.

  In addition, in the present embodiment, the tire side detection unit 200 is mounted on the mounting portion 162 in the present embodiment, but the present invention can be implemented in a mode in which the tire side detection unit 200 is mounted on the support portion 164.

  Next, a fourth embodiment of the present invention will be described. However, since this embodiment has elements in common with the third embodiment, the common elements are cited using the same reference numerals or names, and detailed description thereof is omitted, and only different elements are cited. This will be described in detail.

  In 3rd Embodiment, the support part 164 of the core 160 is comprised with the metal. On the other hand, in the present embodiment, the core 220 is formed of a synthetic resin and has a cross-sectional shape shown in FIG. The core 220 includes an upper plate portion 222 and a lower plate portion 224 that are parallel to each other and are connected to each other by a column portion 226. In the core 220 having such a shape, when a load is input to the core 200 from the outside, distortion is more likely to occur in the column portion 226 than in other portions. Therefore, in the present embodiment, the tire side detection unit 200 is attached to the column portion 226.

  As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are exemplifications, and are based on the knowledge of those skilled in the art including the aspects described in the section of [Disclosure of the Invention]. The present invention can be implemented in other forms with various modifications and improvements.

It is a top view which shows the travelable distance estimation apparatus according to 1st Embodiment of this invention in the state mounted in the vehicle. FIG. 2 is a cross-sectional view partially showing one of the four wheels 10 shown in FIG. 1 and a tire-side detection unit 40 and a tire load state quantity sensor 42 attached to the wheel 10. FIG. 3 is a block diagram conceptually showing a tire side detection unit 40 and a tire load state quantity sensor 42 in FIG. 2 and a hardware configuration of the signal processing device 70 in FIG. 1. It is a figure which shows the example of a display on the screen of the indicator 110 in FIG. 5 is a flowchart conceptually showing the contents of a tire side signal processing program executed by a computer 52 of the tire side detection unit 40 in FIG. 2. 3 is a flowchart conceptually showing the contents of a vehicle body side signal processing program executed by a computer 72 of the signal processing device 70 in FIG. 2. It is a graph for demonstrating the execution content of S35 in FIG. It is a graph for demonstrating the execution content of S36 in FIG. It is a graph for demonstrating the execution result of the vehicle body side signal processing program of FIG. It is a figure which shows another example of a display on the screen of the indicator 110 in FIG. While partially showing one wheel 10 of four wheels with which a vehicle in which a tire information acquisition device according to a 2nd embodiment of the present invention is mounted is shown, tire side detection with which the wheel 10 is equipped It is sectional drawing which shows the unit 40 and the tire load state quantity sensor 170. FIG. It is a block diagram which shows the tire side detection unit 40 in the tire information acquisition apparatus according to the said 2nd Embodiment, the tire load state quantity sensor 170, and the signal processing apparatus 70. FIG. It is a flowchart which represents notionally the content of the tire side signal processing program performed by the computer 52 of the tire side detection unit 40 in FIG. 13 is a flowchart conceptually showing the contents of a vehicle body side signal processing program executed by a computer 72 of the signal processing device 70 in FIG. The tire side mounted on the wheel 10 while partially showing one wheel 10 of the four wheels 10 mounted on the vehicle on which the tire information acquisition device according to the third embodiment of the present invention is mounted. 2 is a cross-sectional view showing a detection unit 200. FIG. FIG. 16 is a block diagram conceptually showing an internal configuration of a tire side detection unit 200 in FIG. 15. A core type run-flat tire core 220 of wheels 10 mounted on a vehicle on which a tire information acquisition device according to a fourth embodiment of the present invention is mounted, and a tire side detection unit mounted on the core 220 FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wheel 20 Tire 32 Side wall 34 Reinforcement part 40,200 Tire side detection unit 42,170 Tire load state sensor 74 Electronic control unit ECU
160,220 Core 172 Strain gauge

Claims (10)

A travelable distance estimation device for estimating a travelable distance in which a runflat tire can travel in a punctured state in a vehicle configured by supporting a wheel on which a runflat tire is mounted on a vehicle body,
A tire load state quantity sensor which is mounted on the run flat tire and detects a tire load state quantity which is a state quantity representing the load of the tire;
A travelable distance estimation device comprising: an estimator that estimates the travelable distance based on the detected tire load state quantity. The run-flat tire includes a shape deformation suppressing portion that suppresses shape deformation of the run-flat tire during vehicle travel without depending on the air pressure inside the run-flat tire,
The travelable distance estimation device according to claim 1, wherein the tire load state quantity sensor is attached to the shape deformation suppression unit and detects a load state quantity of the shape deformation suppression unit as the tire load state quantity.   The travelable distance estimation device according to claim 1 or 2, wherein the tire load state quantity includes a temperature of the run-flat tire.   The travelable distance estimation device according to any one of claims 1 to 3, wherein the tire load state quantity includes a deformation state quantity of the run-flat tire.   The estimator is based on at least one of the detected tire load state quantity, a running speed of the vehicle, a load acting on the run-flat tire, and a state quantity of a road surface on which the vehicle runs; The travelable distance estimation device according to any one of claims 1 to 4, wherein the travelable distance is estimated.   The estimator determines the travelable distance based on the detected tire load state quantity, and determines the travelable distance determined based on the travel speed of the vehicle, the load acting on the run-flat tire, and the vehicle. The travelable distance estimation device according to any one of claims 1 to 4, wherein the travelable distance is corrected based on at least one of state quantities of a road surface on which the vehicle travels.   The amount of tire load state includes a deflection amount of the run flat tire, the travelable distance estimation device further includes a tire air pressure sensor that detects an air pressure of the run flat tire, and the estimator includes the tire load. Based on the amount of deflection detected by the state quantity sensor and the air pressure detected by the tire air pressure sensor, the ground load of the run flat tire is estimated as a load acting on the run flat tire, and the estimated ground contact The travelable distance estimation device according to any one of claims 1 to 6, wherein the travelable distance is estimated based on a load and the detected tire load state quantity. The wheel includes the run-flat tire and the wheel, and the run-flat tire is attached to the wheel, thereby forming an annular tire chamber in the wheel,
The shape deformation suppressing unit is a core disposed in the tire chamber in a posture that partitions the tire chamber into a tread side near the tread of the run-flat tire and a wheel side close to the wheel, and the tread Including one that suppresses the tread from approaching the wheel by selectively contacting
The travelable distance estimation device according to any one of claims 1 to 7, wherein the tire load state quantity sensor is attached to a core of the tire load state quantity sensor on the wheel side. The core is connected to the wheel and a mounting portion that is mounted on the wheel, and the tread approaches the wheel by selectively contacting the tread and supporting the tread from the inside. And a support part for suppressing
The travelable distance estimating device according to claim 8, wherein the tire load state quantity sensor is mounted on at least one of the mounting portion and the support portion on the wheel side. 11. The vehicle according to claim 9 or 10, wherein the tire load state quantity sensor is attached to a portion of the core that responds to a change in the load more sensitively than a mechanical portion of the core. Distance estimation device.

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