JP2022182440A - Method and system for acquiring wear amount of tire tread, and tire - Google Patents

Abstract

To accurately measure the amount of wear of a tread.SOLUTION: A method disclosed herein relates to a tire 10 comprising a tread 34 having a contact patch continuously extending in the circumferential direction along an outer periphery thereof, a magnetic material 12 arranged inside the tread 34, and a magnetic sensor 13 disposed to detect magnetic flux density originating from the magnetic material 12. The method disclosed herein comprises acquiring the amount of wear of the tread 34 on the basis of an output value of the magnetic sensor 13 generated when the tire 10 is continuously stationary for a predetermined period of time, and a correlation between the output value of the magnetic sensor 13 and the amount of wear of the tread 34.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a tire tread wear amount acquisition method, a tire tread wear amount acquisition system, and a tire.

Japanese Patent Laying-Open No. 2019-203831 discloses a wear measurement technique for pneumatic tires. In the pneumatic tire disclosed here, a magnetic material is included in the tread portion. Furthermore, a magnetic sensor for detecting the magnetic flux density of the magnetic field formed by the magnetic material is arranged at a radially enclosed position corresponding to the magnetic material. The magnetic body is formed by dispersing particles of a hard magnetic material in a polymer material and is magnetized in one direction. It is included in the tread portion so that the direction of magnetization of the magnetic material and the radial direction of the tire are aligned. According to such a pneumatic tire, it is said that the wear state of the tire can be grasped by measuring the intensity of the magnetic field that changes with wear.

JP 2019-203831 A

By the way, with regard to a tire in which a magnetic material is arranged in the tread portion, in the technology for grasping the wear state of the tire by measuring the strength of the magnetic field that changes due to wear, the magnetic material arranged in the tread portion is the It is preferable that the strength of the magnetic field be obtained with good accuracy. However, the accuracy of the magnetic field that is simply caused by the magnetic material may vary, and the wear state of the tire cannot be grasped in some cases.

The tire tread wear amount acquisition method disclosed herein includes a tread portion having a ground contact surface that is continuous in the circumferential direction along the outer peripheral surface, a magnetic material disposed inside the tread portion, and a magnetic material. and a magnetic sensor positioned so that magnetic flux density is sensed. The method disclosed here includes the correlation between the output value of the magnetic sensor output when the tire is stopped continuously for a predetermined time, the output value of the magnetic sensor, and the wear amount of the tread portion. and to acquire the amount of wear of the tread portion. According to this wear amount acquisition method, the wear amount of the tread portion can be acquired with high accuracy.

Further, based on the correlation between the output value of the magnetic sensor and the temperature, the output value of the magnetic sensor is corrected. A wear amount of the tread portion may be obtained based on the correlation with the amount. For example, the tire may have a temperature sensor, and the output value of the magnetic sensor may be corrected based on the output value of the temperature sensor. Also, the singular data may be excluded from the output values of the magnetic sensor. Then, the wear amount of the tread portion may be obtained based on the output value of the magnetic sensor after excluding the specific data and the correlation between the output value of the magnetic sensor and the wear amount of the tread portion.

In addition, the tire tread wear amount acquisition system disclosed herein compares the output value of the magnetic sensor output when the tire is stopped continuously for a predetermined time and the output value of the magnetic sensor. and an arithmetic unit configured to acquire the wear amount of the tread portion based on the correlation with the wear amount of the tread portion.

Further, the tire disclosed herein includes a tread portion having a ground-contacting surface continuous in the circumferential direction along the outer peripheral surface, and a magnetic force line disposed at a predetermined position on the tread portion and directed in a predetermined direction. A magnetic body magnetized in an orientation, a magnetic sensor arranged to detect a magnetic flux density caused by the magnetic body, and a controller. The control device is configured to execute a process of determining whether or not the tire is stopped, and a process of recording the output value of the magnetic sensor at least when it is determined that the tire is stopped. there is

FIG. 1 is a schematic diagram of a tire 10 to which a tire tread wear amount acquisition method is applied. FIG. 2 is a schematic diagram of a wear amount acquisition system to which the method disclosed herein is applied. FIG. 3 is a schematic diagram showing an example of a method of excluding singular data. FIG. 4 is a schematic diagram showing an example of a method of excluding singular data. FIG. 5 is an example of a flow chart of the tire tread wear amount acquisition system disclosed herein.

Hereinafter, a tire tread wear amount acquisition method, a wear amount acquisition system, and a tire disclosed herein will be described based on the drawings. In addition, this invention is not limited to the following embodiment. Each drawing is schematically drawn and does not necessarily reflect the real thing. Each drawing only shows an example and does not limit the present invention unless otherwise specified. Further, members and portions that perform the same functions are given the same reference numerals as appropriate, and overlapping descriptions are omitted.

FIG. 1 is a schematic diagram of a tire 10 to which a tire tread wear amount acquisition method is applied. The tire tread wear amount acquisition method disclosed herein acquires the wear amount of the tire tread portion of the tire 10 having the magnetic body 12 provided inside the tread portion 34 as shown in FIG. Regarding the method.

<Structure of tire 10>
As shown in FIG. 1, tire 10 is mounted on wheel rim 30 . The tire 10 includes bead portions 31 , sidewall portions 32 , shoulder portions 33 and tread portions 34 . The bead portion 31 is a portion to be combined with the wheel, and is a portion attached to the wheel rim 30 over the entire circumference. The sidewall portion 32 is a portion along the radial direction on the side surface of the tire 10 . The sidewall portion 32 is the portion where the tire 10 bends the most. The shoulder portion 33 is a portion that connects the sidewall portion 32 and the tread portion 34 . The shoulder portion 33 has a role of dissipating the heat generated inside the tread portion 34 and inside due to friction with the road surface during running.

The tire 10 is a molding of rubber 41 . The rubber 41 incorporates a tire cord called a carcass 42, a belt 43, a bead wire 44, etc., which form the skeleton of the tire 10. As shown in FIG. For the carcass 42, for example, resinous cords made of polymeric materials such as polyester, nylon, and rayon can be used. For the belt 43, for example, a steel wire bundled with high carbon steel is used. For the bead wire 44, for example, a steel wire bundled with high carbon steel is used. Thus, tire cords such as the carcass 42, the belt 43 and the bead wires 44 are members that provide the tire 10 with required mechanical strength. Each tire cord is made of a material having a required mechanical strength.

The carcass 42 is a continuous cord layer inside the tread portion 34 , the shoulder portions 33 on both sides of the tire 10 , the sidewall portions 32 , and the bead portions 31 . The belt 43 is a cord layer arranged on the outer diameter side of the carcass 42 in the tread portion 34 and continuous in the circumferential direction. The bead wire 44 is a ring-shaped reinforcing member in which steel wires are bundled and covered with rubber. The bead wires 44 are arranged on the bead portions 31 on both sides of the tire 10 . An end of the carcass 42 is folded back on the bead wire 44 . A bead wire 44 holds the end of the carcass 42 . The bead wire 44 has the role of receiving the tension applied to the carcass 42 and fixing it to the rim. By incorporating the tire cords in this manner, mechanical strength is ensured to withstand loads, shocks, filling air pressure, and the like. A rubber layer called an inner liner is formed on the inner peripheral surface of the tire 10, inside the tire cords, to ensure airtightness. A rubber layer called an overlayer is formed inside the tire cord, and a tread portion 34 is formed on the surface portion (outer portion) of the overlayer.

Although a so-called radial structure pneumatic tire is exemplified here, the tire is not limited to a radial structure unless otherwise specified. The tires disclosed herein are capable of detecting tread wear as described above. The tire preferably includes a tread portion having a circumferentially continuous contact patch along the outer peripheral surface. In this respect, no particular reference is made to the structure of the tire. The tire may be of so-called bias construction. Also, the tire may be a tube tire having a tube. The tire may be a reddread tire in which only the tread portion 34 can be replaced.

<Tread portion 34>
The tread portion 34 is a portion that directly contacts the road surface, is provided on the outer peripheral surface of the tire 10, and has a ground contact surface that is continuous in the circumferential direction along the outer peripheral surface. The tread portion 34 has a required thickness and is formed with a predetermined pattern of grooves 34a. Such grooves 34a are also referred to as a tread pattern. The tread portion 34 is a portion that gradually wears due to friction with the road surface when the vehicle is running. As the tread portion 34 wears, the grooves 34a forming the tread pattern become shallower. When the tread portion 34 is worn to a predetermined thickness, it is time to replace the tire 10 .

The tread portion 34 is provided with slip signs 34b at a plurality of predetermined locations in the circumferential direction. As the slip sign 34b, a raised portion with a predetermined height is provided at the bottom of the groove 34a of the tread portion 34. As shown in FIG. When the tire is new, the grooves 34a of the tread portion 34 are deep. Therefore, it is difficult for the user to see the raised portion. When the wear of the tread portion 34 progresses, the replacement time of the tire 10 approaches, and the grooves 34a of the tread portion 34 become shallow, the raised portions of the grooves 34a of the tread portion 34 become more visible to the user. When the slip sign 34b becomes visible, it indicates that the time to replace the tire 10 is near. However, it is not directly known to what extent the grooves 34a of the tread portion 34 have been reduced. How much the grooves 34a of the tread portion 34 have decreased can be grasped by actually measuring the depth of the grooves 34a.

A tire 10 to which the method is applied has a magnetic body 12 and a magnetic sensor 13, as shown in FIG. In the tire tread wear amount acquisition method, an estimated value of the tire tread wear amount can be acquired.

<Magnetic body 12>
The magnetic bodies 12 are arranged at predetermined positions on the tread portion 34 . In this embodiment, it is embedded in a predetermined position of the convex portion of the tread portion 34 . In the form shown in FIG. 1, the magnetic body 12 is arranged substantially in the center of the tread portion 34 in the width direction. The magnetic material 12 may be, for example, particles (magnetic powder) made of a hard magnetic material dispersed in a polymer material. The dispersed magnetic powder is preferably magnetized in a predetermined direction.

As a method of providing the magnetic body 12 in the tread portion 34, for example, the following method can be adopted. A hole for embedding the magnetic body 12 is formed at a predetermined position of the convex portion of the tread portion 34 . Separately, a magnetic body 12 formed by dispersing particles (magnetic powder) made of a hard magnetic material in a polymer material is formed into a shape that fits the hole. The molded magnetic body 12 is magnetized in a predetermined direction. Then, the magnetized magnetic body 12 is mounted and adhered to the hole formed in the convex portion of the tread portion 34 .

As another method of providing the magnetic body 12 in the tread portion 34, for example, the magnetic body 12 magnetized in a predetermined direction is prepared. The prepared magnetic body 12 is molded so as to match the holes formed in the convex portions of the tread portion 34 . The molded magnetic body 12 is mounted in the hole formed in the convex portion of the tread portion 34 and adhered. Thus, magnetization may be performed before the magnetic body 12 is embedded in the tread portion 34 or may be performed after the magnetic body 12 is embedded in the tread portion 34 . Although the method of providing the magnetic body 12 in the tread portion 34 is illustrated, the method is not limited to the method illustrated here. Various methods and materials can be employed for the method of attaching the magnetic body 12 and the material of the magnetic powder.

<Magnetic powder>
For example, as the magnetic powder, from the viewpoint that the coercive force after magnetization is large and is not easily demagnetized, aluminum, nickel, cobalt, and iron-based alnico-based magnets and iron oxide as the main component are used. Ferrite magnets, samarium, iron-based samarium-based magnets, neodymium, iron, and boron-based neodymium magnets can be preferably used as magnetic powders for producing neodymium magnets.

Specific alnico magnets include Al—Ni—Co—Fe—Cu, ferrite magnets include Fe ₂ O ₃ —SrO, and samarium magnets include Sm—Co—Fe— Cu, Sm--Fe--N and the like, and neodymium magnets such as Nd--Fe--B--Dy, Nd--Fe--Nb--B and Nd--Pr--Fe--Nb--B.

Two or more of the above magnetic powders may be selected and used. For example, a mixture of ferrite magnetic powder and samarium magnetic powder, and a mixture of samarium magnetic powder and neodymium magnetic powder By mixing, a samarium-ferrite-based magnetic material and a samarium-neodymium-based magnetic material can be formed.

The particle size of the magnetic powder is preferably 400 μm or less, more preferably 250 μm or less, in consideration of the dispersibility in the polymer material when forming the magnetic body 12 and the wear resistance associated with the metal particles. more preferred.

<Polymer material used for magnetic body 12>
As the polymer material used for the magnetic body 12, from the viewpoint of sufficiently exhibiting the characteristics of the tire, a resin material or a rubber material that can exhibit elasticity in a cured state is preferable, and magnetic powder is dispersed. From the viewpoint that the magnetic material formed by the curing wears in the same manner as the tread rubber and provides stable riding comfort, a resin material or rubber material that can exhibit wear characteristics equivalent to the tread rubber composition after curing is used. preferable.

Considering that the tread portion is the location where the magnetic body 12 is provided among the polymer materials described above, the polymer material used for the magnetic body 12 may be the same tread rubber composition as the tread rubber composition used for the tread portion 34. Compound rubber materials may also be used. For example, the magnetic body 12 may have magnetic powder dispersed in a rubber material having the same composition as the tread rubber composition used for the tread portion 34 . Also, for example, a part of the filler in the compounding of the tread rubber composition may be replaced with magnetic powder. The content of the magnetic powder in the magnetic body 12 is preferably 10% to 70% by mass, more preferably 30% to 70% by mass, still more preferably 40% to 70% by mass.

<Magnetism of Magnetic Body 12>
The magnetic body 12 is configured to have a magnetic flux density of 0.05 mT or more at the measurement position where the magnetic sensor 13 is arranged from the viewpoint that the magnetic flux density of the magnetic body can be reliably measured without being affected by the geomagnetism. preferably. In addition, from the viewpoint that the magnetic flux density of the magnetic body 12 can be measured by the magnetic sensor 13 even under the influence of magnetization and attenuation by the steel cord provided inside the tire, the magnetic flux of 0.5 mT or more at the measurement position of the magnetic sensor 13 More preferably, it is configured to have a density. Considering such a point of view, the surface of the magnetic body 12 is preferably configured to have a magnetic flux density of 1 mT or more.

On the other hand, from the viewpoint of preventing the magnetic force of the magnetic body 12 from adversely affecting other electronic devices mounted on the vehicle, the surface magnetic flux density of the magnetic body is preferably approximately 600 mT or less, for example. From the viewpoint of preventing metal pieces such as nails falling on the road surface from being attracted while traveling on the road, it is more preferable that the magnetic flux density of the magnetic body 12 measured on the surface of the tread portion 34 is approximately 60 mT or less, for example. . The magnetic flux density of the magnetic material 12 can be measured with a Tesla meter. For example, the surface magnetic flux density of the magnetic body 12 may be a value measured by directly contacting the magnetized surface of the magnetic body 12 with a Tesla meter. A known magnetizing device such as a capacitor-type magnetizing power supply, a magnetizing coil, or a magnetizing yoke can be used to magnetize the magnetic body 12 .

<Magnetic sensor 13>
The magnetic sensor 13 is arranged on the inner diameter side of the magnetic body 12 . In this embodiment, the magnetic sensor 13 is arranged on the inner peripheral surface of the tire 10 on the inner diameter side of the portion where the magnetic body 12 is embedded in the tread portion 34 . The magnetic bodies 12 are arranged inside the tread portion 34 at predetermined positions in the circumferential direction. The magnetic sensor 13 is arranged so that the magnetic flux density caused by the magnetic body 12 is detected.

As the magnetic sensor 13, a sensor that detects the direction of the magnetic lines of force at the position where the magnetic sensor is arranged can be used. A sensor element that can detect the direction and strength of a magnetic field can be used as the sensor element used in the magnetic sensor 13 . Magneto-resistive (MR) elements such as SMR elements, AMR elements, GMR elements, and TMR elements can be used as such sensor elements. A Hall element may be used as the sensor element used in the magnetic sensor. A magneto-impedance element may be used as the sensor element used in the magnetic sensor. In addition to the sensor elements mentioned here, the magnetic sensor 13 may employ various sensor elements capable of detecting the strength of a magnetic field. The effective measurement range of the magnetic flux density in the magnetic sensor 13 is preferably 1 mT or more, for example.

The SMR element is a semiconductor magnetoresistive element (SMR: Semiconductor Magneto Resistive). An SMR element is a sensor that utilizes changes in resistance value caused by the Lorentz force.

The AMR element is an anisotropic-magneto-resistive (AMR) element. An AMR element is composed of, for example, a Si or glass substrate and a thin film of an alloy mainly composed of a ferromagnetic metal such as Ni or Fe formed thereon. The AMR element exhibits shape anisotropy because domain walls (boundaries between magnetic domains) are aligned in the longitudinal direction by patterning. An AMR element has a characteristic that when a current is passed through a ferromagnetic thin film metal and a magnetic field is applied in a direction perpendicular to the current direction, the resistance value decreases according to the strength of the magnetic field.

A GMR element is a giant magnetoresistive element (GMR: Giant Magneto Resistive) that utilizes the giant magnetoresistive effect. The GMR element is a laminated film of ferromagnetic material (pinned layer) - non-magnetic metal - ferromagnetic material (free layer). The degree of scattering of electrons changes and the resistance value changes depending on whether the directions of the electrodes are aligned.

A TMR element is a tunnel magnetoresistive element (TMR: Tunnel Magneto Resistive). The TMR element is a laminated film of ferromagnetic (pinned layer) - insulator - ferromagnetic (free layer). , the ratio of electrons passing through the insulator changes due to the tunnel effect, and the resistance value changes.

A Hall element is an element that detects magnetism using the Hall effect. According to the Hall element, when a current is passed through a semiconductor thin film or the like, a voltage corresponding to the magnetic flux density and direction is output by the Hall effect.

A magneto-impedance element (MI) is an element that detects an external magnetic field using the magneto-impedance effect.

The magnetic sensor 13 may include one sensor element, or may include a plurality of sensor elements. For example, two or more sensor elements may be arranged in one sensor package that constitutes the magnetic sensor 13 .

For example, when the sensitivity direction of the sensor element used in the magnetic sensor 13 has directivity, one sensor package may include three sensor elements whose sensor sensitivity directions are oriented in the orthogonal three-axis directions. As a result, it is possible to obtain the magnetic sensor 13 that can determine the magnitude and direction of the magnetic force density at the position where the magnetic sensor 13 is arranged.

A plurality of sensor elements may be incorporated in one sensor package that configures the magnetic sensor 13 in this way. Moreover, the same type of elements may be used for the sensor elements incorporated in one sensor package. Moreover, different types of elements such as a Hall element and a magnetoresistive element may be combined in a sensor element incorporated in one sensor package. As for the magnetic sensor, magnetic sensors having various functions are available on the market. The magnetic sensor 13 is preferably arranged on the inner diameter side of the tread portion 34 . The magnetic sensor 13 may be arranged, for example, just inside or near the position where the magnetic body 12 is arranged on the tread portion 34 . Note that the magnetic sensor 13 is preferably capable of detecting the magnitude of the magnetic flux density caused by the magnetic body 12, and is not limited to the inner diameter side of the tread portion 34, and can be arranged in various ways. For example, the magnetic sensor 13 can be arranged at any position inside the tire 10 , such as inside the sidewall portion 32 or the shoulder portion 33 of the tire 10 .

The present inventor is considering detecting the magnetic flux density caused by the magnetic body 12 with the magnetic sensor 13 and acquiring the wear amount of the tread portion 34 based on the magnetic flux density. According to the study of the present inventor, in the tire 10 , the magnetic flux density caused by the magnetic body 12 is detected by the magnetic sensor 13 . The magnetic body 12 is arranged inside the tread portion 34 of the tire. When the tread portion 34 wears, the magnetic body 12 also wears. The magnetic flux density caused by the magnetic body 12 becomes weaker as the tread portion 34 wears. Therefore, theoretically, the wear amount of the tread portion 34 can be obtained based on the magnetic flux density detected by the magnetic sensor 13 . However, according to the knowledge of the present inventor, there are cases in which the amount of wear of the tread portion 34 cannot actually be obtained based on the magnetic flux density detected by the magnetic sensor 13 as theoretically.

According to the findings obtained by the study of the present inventor, for example, when the vehicle is running or immediately after stopping, the influence of disturbance is large, and the magnetic flux density detected by the magnetic sensor 13 tends to be unstable. In addition, according to the findings obtained by the study of the present inventor, even when the vehicle is stopped, the magnetic flux density detected by the magnetic sensor 13 sometimes does not reflect the wear amount of the tire tread portion. Furthermore, the tread portion 34 of the tire 10 is gradually worn out according to the running distance, and the magnetic body 12 is also gradually worn out. Therefore, the magnetic flux density detected by the magnetic sensor 13 due to the magnetic body 12 is also weakened. Therefore, the more the tread portion 34 of the tire 10 is worn, the greater the influence of the disturbance, and the greater the influence of the disturbance on the output value of the magnetic sensor 13 . According to studies by the present inventors, the main disturbance that affects the output value of the magnetic sensor 13 is geomagnetism. Moreover, when the magnetic body 12 is grounded, an appropriate value may not be obtained and an abnormal value may be output. Here, based on such independent studies by the present inventors, a method capable of obtaining the wear amount of the tire tread portion with higher accuracy is proposed.

In the method of acquiring the wear amount of the tire tread portion disclosed here, the output value of the magnetic sensor 13 output when the tire is stopped continuously for a predetermined time and the output value of the magnetic sensor 13 and the correlation with the wear amount of the tread portion 34, the wear amount of the tread portion 34 is acquired. Therefore, the output value of the magnetic sensor 13 acquired during running or immediately after stopping is excluded from the data for obtaining the wear amount of the tread portion 34 . Therefore, the wear amount of the tread portion 34 can be accurately obtained. The correlation between the output value of the magnetic sensor 13 and the amount of wear of the tread portion 34 is preferably prepared in advance by performing a test or the like.

Further, according to the findings of the present inventor, the output value of the magnetic sensor 13 is affected by temperature. Moreover, the magnetic force (magnetic flux density) emitted from the magnetic body 12 changes reversibly. In particular, the tire mounted on the vehicle has a road surface temperature of nearly 60°C during the daytime in summer. Also, at night in winter in cold regions, the temperature may drop to about -15°C or even lower. As described above, the temperature of the tires mounted on the vehicle greatly fluctuates between summer and winter, and between daytime and nighttime. Therefore, the temperature of the tire where the magnetic sensor 13 and the magnetic body 12 are provided may affect the output value of the magnetic sensor 13 . In the method disclosed here for acquiring the wear amount of the tread portion 34, the output value of the magnetic sensor 13 may be corrected based on the correlation between the output value of the magnetic sensor 13 and the temperature. By correcting the output value of the magnetic sensor 13 based on the temperature, the wear amount of the tread portion 34 can be obtained with higher accuracy.

Here, the temperature can be, for example, the temperature measured at the tire provided with the magnetic sensor 13 and the magnetic body 12 . The temperature may be, for example, the temperature measured at or near the position where the magnetic sensor 13 or the magnetic body 12 is provided. The temperature may be the temperature measured at a predetermined position of the vehicle, such as when there is a correlation between the temperature measured at the tire and the temperature measured at the predetermined position of the vehicle. In this case, the tire 10 may have a temperature sensor 22 as a suitable example. Then, the output value of the magnetic sensor 13 may be corrected based on the output value of the temperature sensor 22 . Further, regarding the tire 10 in which the magnetic body 12 is arranged inside the tread portion 34, the correlation between the output value of the magnetic sensor 13 and the temperature may be obtained in advance as reference data through tests. Such correction of the output value of the magnetic sensor 13 based on the temperature is appropriately referred to as "temperature correction".

The temperature sensor 22 may be integrated in a sensor module in which the magnetic sensor 13 is optionally integrated. By incorporating the temperature sensor 22 together with the magnetic sensor 13 into the sensor module, the positional relationship between the temperature sensor 22, the magnetic body 12, and the magnetic sensor 13 becomes constant. Therefore, for example, when correcting the output value of the magnetic sensor 13, the output value of the magnetic sensor 13 can be corrected with high accuracy. Therefore, the wear amount of the tread portion 34 can be obtained more accurately.

Furthermore, peculiar data may be excluded from the output values of the magnetic sensor 13 . According to the findings of the present inventor, the output value of the magnetic sensor 13 may be a specific value. By excluding the peculiar data from the output values of the magnetic sensor 13, the wear amount of the tread portion 34 can be obtained with higher accuracy. For example, quartile deviations may be applied to exclude data that deviate significantly from the median as singular data. As another method, for example, an output value that is at least twice the standard deviation from the average value of the output values of the magnetic sensor 13 and at least twice the standard deviation from the average value may be set as the singular data. In this case, the output value of the magnetic sensor 13 is preferably recorded together with the time information. Then, among the output values of the magnetic sensor 13 recorded together with the time information, the average value and the standard deviation may be obtained within the output values within a predetermined time range. In this way, by excluding data greatly deviating from the median value among the output values of the magnetic sensor 13 as peculiar data, the wear amount of the tread portion 34 can be obtained with higher accuracy. For example, abnormal values that may be output when the magnetic body 12 is grounded may be excluded.

When excluding the peculiar data from the output value of the magnetic sensor 13, the peculiar data may be extracted from the output value of the magnetic sensor 13 and the extracted peculiar data may be excluded. Furthermore, the output value of the magnetic sensor 13 may be temperature-corrected after the peculiar data is excluded. As a result, the amount of data on which correction processing is performed is reduced, and the load required for the processing is reduced. Alternatively, the output value of the magnetic sensor 13 may be temperature-corrected, then specific data may be extracted based on the temperature-corrected value, and the extracted specific data may be excluded. In this case, since the output value of the magnetic sensor 13 is temperature-corrected and then the specific data is extracted, the necessary data can be appropriately evaluated. Then, based on the output value of the magnetic sensor 13 output when the tire 10 is stopped continuously for a predetermined time, among the output values of the magnetic sensor 13 after excluding the peculiar data in this way, It is preferable that the wear amount of the tread portion 34 is acquired.

A wear amount acquisition system embodying the method disclosed herein will be described below. FIG. 2 is a schematic diagram of a wear amount acquisition system to which the method disclosed herein is applied. FIG. 2 shows a configuration in which the tire 10 is mounted on a vehicle 200. As shown in FIG.

The tire 10 preferably includes a tread portion 34, a magnetic body 12, and a magnetic sensor 13, as shown in FIGS. In the form shown in FIG. 2, the tire 10 comprises an acceleration sensor 21, a temperature sensor 22, a pressure sensor 23, a timer 24, a memory 25 and a communication device 26. In this embodiment, since the tire 10 is provided with the acceleration sensor 21, the behavior of the tire 10, such as vibration occurring in the tire 10, can be recorded.

<Temperature sensor 22>
The temperature sensor 22 is a sensor that detects the temperature of the magnetic sensor 13 . In this embodiment, the temperature sensor 22 is attached near the magnetic sensor 13 . An IC temperature sensor that can be incorporated in the microcomputer 50 can be applied to the temperature sensor 22 . With such a temperature sensor 22, the influence of the temperature of the magnetic sensor 13 can be taken into consideration. It should be noted that the temperature sensor 22 may be any sensor that can roughly detect the temperature of the magnetic sensor 13 . A temperature sensor disposed inside the tire 10 can be appropriately adopted as the temperature sensor 22 .

<Pressure sensor 23, timer 24>
The pressure sensor 23 is a sensor that detects the internal pressure of the tire 10 . The pressure sensor 23 can be built into the microcomputer 50 . By providing the tire 10 with the pressure sensor 23 that detects the internal pressure, the air pressure of the tire 10 can be monitored. Timer 24 may be a timer built into microcomputer 50 .

<Memory 25>
The memory 25 preferably records the output values of the magnetic sensor 13 . In the form shown in FIG. 1, the tire 10 has a microcomputer 50 as an arithmetic device. Memory 25 may be incorporated in microcomputer 50 .

<Communication device 26>
The communication device 26 is a device that transmits data recorded in the microcomputer 50 to an external device outside the tire 10 . The communication device 26 may employ, for example, a communication device capable of wireless communication. The communication device 26 preferably adopts a communication standard conforming to a short-range wireless communication standard such as the so-called BLE communication standard (Bluetooth Low Energy). The communication device 26 can be built into the microcomputer 50 .

<Power supply 27>
The power source 27 may be a battery such as a button battery. Moreover, the power supply 27 may be configured by a power generating element and a storage element. An element that generates power based on vibrations generated in the tire 10 may be used as the power generation element. Also, a power storage element may be provided in accordance with the power generation element.

At least part of the magnetic sensor 13, acceleration sensor 21, temperature sensor 22, pressure sensor 23, timer 24, communication device 26, power supply 27, microcomputer 50, etc. may be unitized as one device. The unitized device may be configured, for example, as a so-called MEMS device (MEMS: Micro Electro Mechanical Systems). Also, the unitized device may be attached to the inner surface of the tire 10 . Tire 10 may thus comprise memory 25 and communication device 26 .

For example, in the form shown in FIGS. 1 and 2, the vehicle 200 is equipped with the vehicle-mounted device 80 . A microcomputer 50 mounted on the tire 10 is communicably connected to an on-vehicle device 80 . The vehicle-mounted device 80 may be composed of a microcomputer mounted for acquiring the wear amount of the tire tread portion. Moreover, the vehicle-mounted device 80 may be configured by an ECU mounted on the vehicle 200 . The vehicle-mounted device 80 may acquire information from the vehicle 200 in cooperation with the ECU of the vehicle 200 .

The vehicle-mounted device 80 may be communicably connected to the cloud server 400 through a communication network NW such as the Internet. Vehicle-mounted device 80 may be connected to cloud server 400 via the Internet, for example, in cooperation with another ECU (ECU: electronic control unit) mounted on vehicle 200 . In this manner, vehicle 200 may be communicably connected to cloud server 400 via the Internet as appropriate.

A tire tread wear amount acquisition system 100 disclosed herein relates to a tire 10 having a magnetic body 12 disposed inside a tread portion 34 and a magnetic sensor 13, as shown in FIG. The wear amount acquisition system 100 includes an arithmetic unit 60 as shown in FIG. The computing device 60 calculates the output value of the magnetic sensor 13 output when the tire 10 is stopped continuously for a predetermined time, and the correlation between the output value of the magnetic sensor 13 and the wear amount of the tread portion 34. and the amount of wear of the tread portion 34 is acquired. As a result, the wear amount of the tread portion 34 can be obtained based on the output value of the magnetic sensor 13 output while the tire 10 is stopped continuously for a predetermined time.

According to the findings of the present inventor, the output values of the magnetic sensor 13 obtained during running tend to vary greatly. Therefore, when trying to obtain the wear amount of the tread portion 34 based on the output value of the magnetic sensor 13 obtained during running, the wear amount of the tread portion 34 cannot be obtained (measured, measured, estimated, etc.) with high accuracy. The wear amount of the tread portion 34 is obtained by obtaining the wear amount of the tread portion 34 based on the output value of the magnetic sensor 13 output when the tire 10 is stopped continuously for a predetermined time. Accuracy can be improved.

Tire 10 may have a temperature sensor 22 . The computing device 60 is configured to correct the output value of the magnetic sensor 13 based on the output value of the temperature sensor 22 and the previously prepared correlation between the output value of the magnetic sensor 13 and the temperature. may As a result, the output value of the magnetic sensor 13 is appropriately corrected, so the accuracy of the obtained wear amount of the tread portion 34 is improved.

The computing device 60 may be configured to exclude peculiar data from the output values of the magnetic sensor 13 . As a result, peculiar data is excluded from the output values of the magnetic sensor 13, so that the accuracy of the obtained wear amount of the tread portion 34 is improved. Since the output value of the magnetic sensor 13 is appropriately corrected, the accuracy of the obtained wear amount of the tread portion 34 is improved.

FIG. 3 is a schematic diagram showing an example of a method of excluding singular data. In FIG. 3, the horizontal axis represents the magnetic flux density as the output value of the magnetic sensor 13, and the vertical axis represents the frequency. Arrange the data in order of magnitude, and calculate the quartered values of 25% (Q1: Quartile 1), 50% (Q2: Quartile 2) (=median), and 75% (Q3: Quartile 3). Then, an interquartile range IQR (Q1-Q3) from 25% (Q1: Quartile 1) to 75% (Q3: Quartile 3) is obtained. Furthermore, the output values of the magnetic sensor 13 from Q1 + 1.5 × IQR to Q3 + 1.5 × IQR are adopted as population data, and the outlier value Dx1 ~ Dx3 is excluded as singular data. As a result, it is possible to exclude values far from the average value among the output values of the magnetic sensor 13 . This suppresses variations in the output values of the magnetic sensor 13 . Then, the accuracy of the acquired wear amount of the tread portion 34 is improved.

FIG. 4 is a schematic diagram showing an example of a method of excluding singular data. As shown in FIG. 4, data outside the range of ±2σ may be excluded from the average value of the output values of the magnetic sensor 13 as singular data. In this case also, it is possible to exclude values far from the average value among the output values of the magnetic sensor 13 . This suppresses variations in the output values of the magnetic sensor 13 . Then, the accuracy of the acquired wear amount of the tread portion 34 is improved. As described above, various statistical analysis methods can be adopted as a method of excluding data greatly deviating from the average value among the output values of the magnetic sensor 13 as peculiar data.

In the form shown in FIG. 2 , the computing device 60 is provided outside the tire 10 . The tire 10 is preferably provided with a communication device 50a that transmits the output value of the magnetic sensor 13 to an external device. The communication device 50a may be incorporated in a microcomputer 50 provided in the tire 10, for example. The microcomputer 50 is preferably configured to transmit the output value of the magnetic sensor 13 to the computing device 60 through the communication device 50a.

For example, as shown in FIGS. 1 and 2, the computing device 60 may be provided in a vehicle-mounted device 80 provided in a vehicle 200 on which the tire 10 is mounted. Further, arithmetic device 60 may be provided in cloud server 400 connected to vehicle 200 on which tire 10 is mounted through communication network NW. Since the computing device 60 is provided outside the tire 10 in this manner, calculations requiring a high computing load, such as calculation of the wear amount of the tread portion 34, can be performed by a higher performance computing device.

In the form shown in FIGS. 1 and 2, the arithmetic device 60 is incorporated in the vehicle-mounted device 80 . For example, it is preferable that a microcomputer incorporated in the vehicle-mounted device 80 incorporates the function of the arithmetic device 60 . The vehicle-mounted device 80 is preferably configured to acquire speed information of the vehicle 200 on which the tires 10 are mounted. The vehicle-mounted device 80 may be configured to acquire speed information of the vehicle 200 from an electronic control unit (ECU) of the vehicle 200, for example. The arithmetic unit 60 incorporated in the vehicle-mounted device 80 acquires the speed information of the vehicle 200 from the vehicle-mounted device 80, and detects the magnetic sensor 13 output when the tire 10 is stopped continuously for a predetermined time. configured to obtain an output value. The vehicle-mounted device 80 may be further configured to acquire the wear amount of the tread portion 34 based on the correlation between the output value of the magnetic sensor 13 and the wear amount of the tread portion 34 . In this case, the vehicle-mounted device 80 may be configured to appropriately notify the driver of the calculated wear amount of the tread portion 34 of the tire 10 .

Further, the arithmetic device 60 incorporated in the vehicle-mounted device 80 may be configured to appropriately correct the output value of the magnetic sensor 13 based on the correlation between the output value of the magnetic sensor 13 and the temperature. good. Further, the arithmetic device 60 incorporated in the vehicle-mounted device 80 may be configured to exclude singular data from the output values of the magnetic sensor 13 .

Note that the arithmetic device 60 is not limited to being incorporated in the vehicle-mounted device 80 . For example, the cloud server 400 may incorporate the functions of the computing device 60 . In this case, cloud server 400 may be configured to be connected to vehicle 200 on which tire 10 is mounted through a communication network.

In this case, the cloud server 400 acquires the speed information of the vehicle 200 from the vehicle-mounted device 80, and obtains the output value of the magnetic sensor 13 output when the tires 10 are stopped continuously for a predetermined time. may be configured to The cloud server 400 can improve the performance of the arithmetic unit so that calculation with a higher load than the on-vehicle device 80 is possible. Moreover, it is not necessary to improve the performance of the arithmetic unit incorporated in the vehicle-mounted device 80 . Therefore, the cost of the vehicle-mounted device 80 can be kept low compared to the case where the vehicle-mounted device 80 has the function of the arithmetic unit 60 . Also, the cloud server 400 can transmit information through a communication network such as the Internet. Therefore, the calculated wear amount of the tread portion 34 of the tire 10 can be widely notified by a predetermined terminal such as a predetermined mobile terminal of the driver or a terminal of the mechanic who maintains the vehicle 200 .

Next, as shown in FIG. 1, the tire 10 disclosed here includes a tread portion 34, a magnetic body 12, a magnetic sensor 13, and a microcomputer 50 as a control device. The magnetic body 12 is arranged at a predetermined position on the tread portion 34 and is magnetized so that the lines of magnetic force are oriented in a predetermined direction. The magnetic sensor 13 is arranged to detect the magnetic flux density caused by the magnetic body 12 . The microcomputer 50 as a control device executes a process of determining whether or not the tire 10 is stopped, and a process of recording the output value of the magnetic sensor 13 when it is determined that the tire 10 is stopped. is configured to In this case, the tire 10 records the output value of the magnetic sensor 13 in the memory 25 when it is determined that the tire 10 is stopped. Therefore, this tire 10 is suitable for calculating the wear amount of the tread portion 34 based on the output value of the magnetic sensor 13 acquired when it is determined that the tire 10 is stopped. The output value of the magnetic sensor 13 may not be recorded except when it is determined that the tire 10 is stopped. In this case, since the output value of the magnetic sensor 13 recorded in the memory 25 is reduced, the capacity of the memory 25 can be reduced.

The microcomputer 50 may be configured to communicate with an external device such as a vehicle-mounted device 80 through the communication device 26 incorporated in the tire 10 . Then, it may be configured to determine whether the tire 10 is stopped based on a signal (information) acquired from an external device. For example, the microcomputer 50 may be configured to communicate with the vehicle-mounted device 80 as described above.

In this case, the process of determining whether the tire 10 is stopped may be configured to determine whether the tire 10 is stopped based on information acquired from the vehicle-mounted device 80. . Further, tire 10 may be configured to communicate with an external device and record the output value of magnetic sensor 13 based on a signal from the external device. For example, it may be configured to record the output value of the magnetic sensor 13 based on the signal from the vehicle-mounted device 80 . In this case, the timing at which the microcomputer 50 of the tire 10 records the output value of the magnetic sensor 13 can be determined arbitrarily, regardless of whether the tire 10 is stopped.

In this case, it is determined whether or not the tire 10 is stopped based on the information acquired by the vehicle 200 . The information acquired by the vehicle 200 is based on the information acquired by the vehicle 200, such as the speed information of the vehicle 200, the fact that the engine is stopped, and the fact that the ignition switch of the vehicle 200 is turned off. Then, it can be determined whether the tire 10 is stopped. The microcomputer 50 incorporated in the tire 10 receives a signal indicating that the ignition switch of the vehicle 200 has been turned off, for example, through communication with the vehicle-mounted device 80 . Then, the output value of the magnetic sensor 13 may be recorded at a predetermined timing by sequence control from the timing when the signal indicating that the ignition switch of the vehicle 200 is turned off is received. As a result, the output value of the magnetic sensor 13 required for calculating the amount of wear of the tread portion 34 is properly recorded.

Tire 10 may further include a temperature sensor 22, as shown in FIG. The microcomputer 50 as a control device may be configured to record the output value of the temperature sensor 22 together with the output value of the magnetic sensor 13 in the memory 25 . In this case, according to the tire 10 , the output value of the magnetic sensor 13 can be corrected based on the output value of the temperature sensor 22 . Therefore, the acquired wear amount of the tread portion 34 can be obtained with high accuracy.

The microcomputer 50 incorporated in the tire 10 is preferably configured to transmit recorded information to an external device. For example, the microcomputer 50 may be configured to transmit information recorded in the memory 25 by the communication device 26 to an external device such as the vehicle-mounted device 80 . In this case, the output value of the magnetic sensor 13 can be transferred from the microcomputer 50 to the vehicle-mounted device 80 and further transferred to the cloud server 400 (see FIG. 2). Then, the wear amount of the tread portion 34 of the tire 10 can be calculated based on the output value of the magnetic sensor 13 by the vehicle-mounted device 80 or the cloud server 400 .

For example, the communication device 26 communicates with the vehicle-mounted device 80 . The vehicle-mounted device 80 appropriately issues a signal to the communication device 26 requesting that the output value of the magnetic sensor 13 be transferred to the communication device 26 . The communication device 26 may be configured to transfer the output value of the magnetic sensor 13 stored in the memory 25 to the vehicle-mounted device 80 when the signal is received from the vehicle-mounted device 80 . Further, the vehicle-mounted device 80 sends a signal requesting the communication device 26 of the tire 10 to transfer the output value of the magnetic sensor 13 to the vehicle-mounted device 80, for example, when the ignition switch of the vehicle 200 is turned on. 26. Further, the microcomputer 50 may be configured to transfer the output value of the magnetic sensor 13 stored in the memory 25 to the vehicle-mounted device 80 at pre-programmed timing.

Tire 10 may be provided with a power source 27 as described above. The power source 27 may be a battery such as a button battery. Moreover, the tire 10 may include a power generation element and a power storage element as the power source 27 . An element that generates power based on vibrations generated in the tire 10 may be used as the power generation element. Also, a power storage element may be provided in accordance with the power generation element. As described above, it is preferable that the tire 10 incorporates the power source 27 as a drive power source for the microcomputer 50 .

FIG. 5 is an example of a flow chart of the tire tread wear amount acquisition system disclosed herein.

The flowchart shown in FIG. 5 starts with the ignition switch of the vehicle 200 turned off. At this time, the microcomputer 50 is resting (S11). IG in the flowchart of FIG. 5 means an ignition switch of vehicle 200 .

When the vehicle 200 is stopped for a certain period of time, the microcomputer 50 of the tire 10 is at rest. It is preferable that the microcomputer 50 is configured so that the magnetic sensor 13 is acquired at predetermined intervals even during rest. The microcomputer 50 may be configured to store the output value of the magnetic sensor 13 for a predetermined number of times, for example, in a 30-minute cycle based on the built-in timer 24 .

In this embodiment, when the ignition switch of the vehicle 200 is turned on, the vehicle-mounted device 80 is turned on (S51). Then, when the vehicle-mounted device 80 is turned on, the communication device with the microcomputer 50 is also activated (S52). When the vehicle-mounted device 80 is turned on, the vehicle-mounted device 80 transmits a wireless communication signal, and communication between the vehicle-mounted device 80 and the microcomputer 50 becomes possible. Although not shown, the microcomputer 50 may be activated when communication between the vehicle-mounted device 80 and the microcomputer 50 becomes possible. For example, a predetermined signal for activating the microcomputer 50 may be transmitted from the vehicle-mounted device 80, and the microcomputer 50 may be activated when the signal is received.

When activated, the microcomputer 50 determines, for example, whether or not the vehicle 200 is running (S14). In this embodiment, the microcomputer 50 may be configured to determine whether or not the tire 10 is stopped based on communication with the vehicle-mounted device 80 . For example, the microcomputer 50 acquires speed information of the vehicle 200 from the vehicle-mounted device 80 . Then, when the speed of the vehicle 200 is 0, it may be determined that the tire 10 is stopped. The microcomputer 50 may acquire the speed information of the vehicle 200 from the vehicle-mounted device 80 at a predetermined cycle, for example, at a short cycle of about one second.

Further, the microcomputer 50 may be configured to transfer the output value of the magnetic sensor 13 stored in the memory 25 of the tire 10 to the vehicle-mounted device 80 (S15). For example, the data of the output value of the magnetic sensor 13 that the microcomputer 50 recorded while it was resting is transferred to the vehicle-mounted device 80 . The process of transferring the output value of the magnetic sensor 13 stored in the memory 25 of the tire 10 to the vehicle-mounted device 80 may be performed after the microcomputer 50 is activated and the vehicle-mounted device 80 becomes communicable. good. After transferring the output values of the magnetic sensor 13 stored in the memory 25 to the vehicle-mounted device 80 , the microcomputer 50 may erase all the output values of the magnetic sensor 13 stored in the memory 25 . After transferring the output values of the magnetic sensor 13 stored in the memory 25 to the vehicle-mounted device 80, the microcomputer 50 overwrites the output values of the magnetic sensor 13 stored in the memory 25 in chronological order. may be configured.

<Data acquisition 1: S16>
In this embodiment, the microcomputer 50 acquires data from the tires 10 at shorter intervals while the vehicle is running (S16). Here, the acquired data are magnetic flux density M, internal pressure P, temperature T, and the like. A magnetic flux density M is obtained as an output value of the magnetic sensor 13 . The internal pressure P is obtained as an output value of the pressure sensor 23 . A temperature T is obtained as an output value of the temperature sensor 22 . Also, if the tire 10 incorporates another sensor such as the acceleration sensor 21, the output value of the other sensor such as the acceleration sensor 21 may also be obtained. Data acquisition here is preferably performed, for example, every minute. Further, in this embodiment, while the vehicle is running, the output value of the magnetic sensor 13 stored in the memory 25 of the tire 10 is appropriately transferred to the vehicle-mounted device 80 (S16). For example, while driving, the output value of the magnetic sensor 13 stored in the memory 25 of the tire 10 may be transferred to the vehicle-mounted device 80 every minute. As a result, not only the output value of the magnetic sensor 13 but also the data of the running tire 10 such as the temperature and the internal pressure can be sequentially acquired by the vehicle-mounted device 80 . As a result, the condition of the tire 10 during running can be checked through the vehicle-mounted device 80. - 特許庁

The microcomputer 50 determines whether or not the tire 10 is stopped (S18) each time in the process of data acquisition 1 (S16). In this embodiment, the microcomputer 50 shifts to the data acquisition 2 process (S19) when the tires 10 are stopped in this determination (S18).

<Data Acquisition 2: S19>
In the data acquisition 2 process (S19), for example, data is acquired from the tire 10 in a cycle of one minute. The acquired data are sequentially transferred to the vehicle-mounted device 80 (S20). If the ignition switch is turned off during the data acquisition 2 process, communication with the vehicle-mounted device 80 may be interrupted. In that case, the microcomputer 50 is preferably configured to store the data of the tire 10 acquired in the data acquisition 2 process (S19) in the memory 25. FIG. The microcomputer 50 determines whether or not the tire 10 is stopped (S21) each time in the process of data acquisition 2 (S19). The data acquisition 2 process (S19) is data acquisition during suspension. If the tire 10 is not stopped (No), in other words, if the tire 10 starts to move, the process proceeds to data acquisition 1 (S16), which is data acquisition during running.

In the determination process of S21, if the tires 10 have stopped continuously for about 10 minutes (Yes), the microcomputer 50 proceeds to the data acquisition 3 process (S22) while the vehicle is stopped. In the data acquisition 3 process (S22) while the vehicle is stopped, data is acquired from the tires 10 at intervals of about 30 minutes. At this time, if communication with the vehicle-mounted device 80 is possible, such as when the ignition switch is ON, the data may be transferred to the vehicle-mounted device 80 (S23). Further, when communication with the vehicle-mounted device 80 is interrupted, such as when the ignition switch is turned off, the microcomputer 50 stores the data of the tire 10 acquired in the data acquisition 3 process (S22) in the memory 25. It should be configured as follows.

The microcomputer 50 determines whether or not the vehicle 200 is running in the determination process (S24) that is performed each time in the data acquisition 3 process. Such determination processing ( S<b>24 ) is preferably determined by communication with the vehicle-mounted device 80 . For example, when a signal indicating that the vehicle speed is 0 is obtained through communication with the vehicle-mounted device 80, or when communication with the vehicle-mounted device 80 is stopped, it can be determined that the tires 10 are stopped. On the other hand, when the vehicle 200 is running (Yes), the state is determined based on the signal obtained by communication with the vehicle-mounted device 80 . In this embodiment, when the vehicle 200 is running (Yes), the state (S13) when the microcomputer 50 is activated is restored. Then, the state stored in the memory 25 is transferred to the vehicle-mounted device 80 (S15). Further, the process of data acquisition 1 during running (S16) is performed.

Further, in the determination process (S24) that is performed each time in the process of data acquisition 3, if the tire 10 has stopped continuously for a predetermined number of times (No), the microcomputer 50 stops (S11). . In this embodiment, the process of data acquisition 3 (S22) is performed in a cycle of 30 minutes. When the data acquisition 3 process (S22) continues 18 times, the microcomputer 50 is configured to stop (S25). In other words, when the vehicle 200 has been parked for approximately nine hours or longer, the microcomputer 50 is put into a resting state after the data of the tires 10 are acquired every 30 minutes while the vehicle is parked. As a result, the power consumption of the power source 27 mounted on the tire 10 can be kept low. Here, the microcomputer 50 is configured to stop when the determination process (S24) performed in a cycle of 30 minutes continues 18 times (in other words, when it continues for 9 hours). The period of S24) is not limited to 30 minutes. Also, the time and number of times that the tire 10 continues to be in a non-moving state is not limited to 18 times or 9 hours, but can be set to an appropriate number and time to stop the microcomputer 50.例文帳に追加

In this way, the output value (magnetic flux density M) of the magnetic sensor 13, the output value (internal pressure P) of the pressure sensor 23, the output value (temperature T) of the temperature sensor 22, and the like are obtained from the tire 10 as appropriate. These data are preferably recorded in the memory 25 in association with the time data by the function of the timer 24 mounted on the microcomputer 50 . The data recorded in the memory 25 may be configured to be transferred to the vehicle-mounted device 80 of the vehicle 200 at any time. As a result, data of the tire 10 is acquired by the vehicle-mounted device 80 at any time.

Further, according to the wear amount acquisition method and the wear amount acquisition system disclosed herein, the output value of the magnetic sensor 13 output when the tire 10 is stopped and the output value of the magnetic sensor 13 prepared in advance and the correlation with the wear amount of the tread portion 34, the wear amount of the tread portion 34 can be obtained. In this case, the wear amount of the tread portion 34 can be obtained based on the output value of the magnetic sensor 13 output when the acceleration of the tire 10 is equal to or less than the predetermined value continuously for a predetermined time. Therefore, the wear amount of the tread portion 34 can be estimated with high accuracy.

For example, the wear amount of the tread portion 34 may be acquired by extracting only the data acquired in the process of data acquisition 3 from among the data of the tire 10 acquired as described above. . Moreover, the wear amount of the tread portion 34 may be obtained by further correcting the temperature of the data obtained by the data obtaining process 3 . Further, the wear amount of the tread portion 34 may be obtained by excluding the peculiar data from the data obtained in the data obtaining process 3 .

Various descriptions have been given above of the tire and wear amount acquisition system disclosed herein, but unless otherwise specified, the tire and wear amount acquisition system disclosed herein are not limited to the above-described embodiments and modifications. In addition, various configurations of the embodiments and modified examples can be appropriately combined as long as they do not hinder each other.

10 tire 12 magnetic body 13 magnetic sensor 21 acceleration sensor 22 temperature sensor 23 pressure sensor 24 timer 25 memory 26 communication device 27 power supply 30 wheel rim 31 bead portion 32 sidewall portion 33 shoulder portion 34 tread portion 34a groove 34b slip sign 41 rubber 42 Carcass 43 Belt 44 Bead wire 50 Microcomputer 60 Arithmetic device 80 Vehicle-mounted device 100 Wear amount acquisition system 200 Vehicle 400 Cloud server NW Communication network

Claims (23)

a tread portion having a ground contact surface that is continuous in the circumferential direction along the outer peripheral surface;
a magnetic body disposed inside the tread portion;
Regarding a tire having a magnetic sensor arranged so as to detect the magnetic flux density caused by the magnetic body,
Based on the output value of the magnetic sensor output when the tire is stopped continuously for a predetermined time and the correlation between the output value of the magnetic sensor and the wear amount of the tread portion, A wear amount acquisition method of a tire tread portion, comprising acquiring the wear amount of the tread portion. 2. The method of claim 1, further comprising correcting the output value of the magnetic sensor based on the correlation between the output value of the magnetic sensor and temperature. a tread portion having a ground contact surface that is continuous in the circumferential direction along the outer peripheral surface;
a magnetic body disposed inside the tread portion;
Regarding a tire having a magnetic sensor arranged to detect the magnetic flux density caused by the magnetic body,
correcting the output value of the magnetic sensor based on the correlation between the output value of the magnetic sensor and the temperature;
Acquiring the wear amount of the tread portion based on the corrected output value of the magnetic sensor and a previously prepared correlation between the output value of the magnetic sensor and the wear amount of the tread portion. A method for acquiring the amount of wear of a tire tread. Acquiring the amount of wear of the tread portion based on the output value of the magnetic sensor that is output when the tire is stopped continuously for a predetermined time, among the corrected output values of the magnetic sensor. 4. The method of claim 3, further comprising: 5. A method according to any one of claims 2 to 4, wherein the tire has a temperature sensor and the output value of the magnetic sensor is corrected based on the output value of the temperature sensor. 6. A method according to any one of claims 1 to 5, further comprising excluding anomalous data among the output values of the magnetic sensor. a tread portion having a ground contact surface that is continuous in the circumferential direction along the outer peripheral surface;
a magnetic body disposed inside the tread portion at a predetermined position in the circumferential direction;
Regarding a tire having a magnetic sensor arranged to detect the magnetic flux density caused by the magnetic body,
Excluding singular data among the output values of the magnetic sensor;
Acquiring the wear amount of the tread portion based on the output value of the magnetic sensor after the singular data is excluded and the correlation between the output value of the magnetic sensor and the wear amount of the tread portion. A method for acquiring a wear amount of a tire tread portion, comprising: Based on the output value of the magnetic sensor output when the tire is stopped continuously for a predetermined time, among the output values of the magnetic sensor after the peculiar data is excluded, the tread portion 8. The method according to claim 7, wherein the amount of wear is obtained. a tread portion having a ground contact surface that is continuous in the circumferential direction along the outer peripheral surface;
a magnetic body disposed inside the tread portion;
Regarding a tire having a magnetic sensor arranged to detect the magnetic flux density caused by the magnetic body,
Based on the output value of the magnetic sensor output when the tire is stopped continuously for a predetermined time and the correlation between the output value of the magnetic sensor and the wear amount of the tread portion, A wear amount acquisition system for a tire tread portion, comprising an arithmetic device configured to acquire the wear amount of the tread portion. The tire has a temperature sensor,
10. The computing device is configured to correct the output value of the magnetic sensor based on the output value of the temperature sensor and the correlation between the output value of the magnetic sensor and the temperature. system described in. 11. The system according to claim 9 or 10, wherein said arithmetic unit is configured to exclude singular data among the output values of said magnetic sensor. 12. A system according to any one of claims 9 to 11, wherein said tire comprises a communication device for transmitting the output value of said magnetic sensor to an external device. The system according to any one of claims 9 to 12, wherein the arithmetic unit is provided in a vehicle-mounted device provided in a vehicle on which the tire is mounted. The vehicle-mounted device acquires speed information of the vehicle on which the tire is mounted,
The computing device is configured to acquire speed information of the vehicle from the vehicle-mounted device and obtain an output value of the magnetic sensor output when the tire is stopped continuously for a predetermined time. 14. A system according to claim 13. 15. The system according to any one of claims 9 to 14, wherein said computing device is provided in a cloud server connected through a communication network to a vehicle on which said tire is mounted. The cloud server acquires speed information of the vehicle from the vehicle-mounted device, and obtains the output value of the magnetic sensor output when the tire is stopped continuously for a predetermined time. 16. A system as claimed in claim 15. a tread portion having a ground contact surface that is continuous in the circumferential direction along the outer peripheral surface;
a magnetic body disposed inside the tread portion;
a magnetic sensor arranged to detect a magnetic flux density caused by the magnetic material;
a control device;
The control device is
A process of determining whether the tires are stopped;
and recording the output value of the magnetic sensor at least when it is determined that the tire is stopped. The controller is configured to communicate with an external device and determine whether the tire is stationary based on a signal from the external device.
18. Tire according to claim 17. The control device communicates with an external device and records the output value of the magnetic sensor based on a signal from the external device.
A tire according to claim 17 or 18. further equipped with a temperature sensor,
20. Tire according to any one of claims 17 to 19, wherein the controller records the output value of the temperature sensor together with the output value of the magnetic sensor. 21. A tire as claimed in any one of claims 17 to 20, wherein the control device is arranged to transmit the recorded information to an external device. 22. A tire as claimed in any one of claims 17 to 21, further comprising a power source. 23. A tire according to any one of claims 17 to 22, further comprising a power generating element and an electrical storage means.

Images