# US 12,214,626 B2 · Tire wear state detection device using waveform data

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- Number: US 12,214,626 B2
- Document ID: US12214626B2
- Status: Granted
- Kind: B2
- Application number: 17/759,419
- Filed: 2021-01-15
- Published: 2023-03-16
- Granted: 2025-02-04
- Earliest claimed: 2020-01-29
- Assignees: The Yokohama Rubber Co., Ltd.
- Applicants: The Yokohama Rubber Co., LTD.
- Inventors: Masahiro Naruse; Jun Matsuda; Heishiro Fudo; Eiji Shinohara; Shinya Ichise; Hiroyuki Tobari; Yuki Ono
- Web page: https://patentgrep.com/patent/US12214626B2

## CPC

- B60C 11/243: {Tread wear sensors, e.g. electronic sensors}
- B60C 11/246: {Tread wear monitoring systems}
- B60C 23/0493: {for attachment on the tyre}
- B60C 2019/004: {Tyre sensors other than for detecting tyre pressure}
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES

## Abstract

A wear state detection device includes an element configured to generate voltage based on deformation of a tread portion during tire rotation, a voltage detection unit configured to detect the voltage generated by the element, a speed detection unit configured to detect vehicle speed or tire rotation speed, a storage area configured to store waveform data over time of the voltage detected by the voltage detection unit together with the vehicle speed or the tire rotation speed detected by the speed detection unit, a calculation unit configured to calculate frequency of exceedance of a predetermined threshold value based on the waveform data in a predetermined speed range and a predetermined time period stored in the storage area, and a determination unit configured to determine a progress condition of wear of the tread portion based on the frequency of exceedance of the predetermined threshold value calculated by the calculation unit.

## Claims

### Claim 1

A wear state detection device comprising:
an element configured to generate voltage based on deformation of a tread portion during tire rotation;
a voltage detection unit configured to detect the voltage generated by the element;
a speed detection unit configured to detect vehicle speed or tire rotation speed;
a storage area configured to store waveform data over time of the voltage detected by the voltage detection unit together with the vehicle speed or the tire rotation speed detected by the speed detection unit;
a calculation unit configured to calculate frequency of exceedance of a predetermined threshold value based on the waveform data in a predetermined speed range and a predetermined time period stored in the storage area; and
a determination unit configured to determine a progress condition of wear of the tread portion based on the frequency of exceedance of the predetermined threshold value calculated by the calculation unit.

### Claim 2 (depends on 1)

The wear state detection device according to claim 1, comprising an air pressure detection unit configured to detect air pressure inside a tire, wherein the calculation unit corrects the waveform data or the predetermined threshold value based on the air pressure detected by the air pressure detection unit.

### Claim 3 (depends on 1)

The wear state detection device according to claim 1, wherein the determination unit performs at least two determination operations, and conclusively determines the progress condition of the wear of the tread portion based on results of the determination operations.

### Claim 4 (depends on 1)

The wear state detection device according to claim 1, wherein a sensor module comprising at least the element and the voltage detection unit is fixed to a tire inner surface via a container into which the sensor module is inserted.

### Claim 5 (depends on 4)

The wear state detection device according to claim 4, wherein
the container is bonded to the tire inner surface via an adhesive layer, and
as roughness of the tire inner surface, an arithmetic mean height Sa ranges from 0.3 μm to 15.0 μm, and a maximum height Sz ranges from 2.5 μm to 60.0 μm.

### Claim 6 (depends on 4)

The wear state detection device according to claim 4, wherein a width Lc1 of an opening portion of the container and an inner width Lc2 of a bottom surface of the container satisfy a relationship of Lc1<Lc2.

### Claim 7 (depends on 4)

The wear state detection device according to claim 4, wherein a width Lc1 of an opening portion of the container and a maximum width Lsm of the sensor module satisfy a relationship of 0.10≤Lc1/Lsm≤0.95.

### Claim 8 (depends on 4)

The wear state detection device according to claim 4, wherein a width Lc1 of an opening portion of the container, an inner width Lc2 of a bottom surface of the container, a width Ls1 of an upper surface of the sensor module, and a width Ls2 of a lower surface of the sensor module satisfy a relationship of Lc1<Ls1≤Ls2<Lc2.

### Claim 9 (depends on 4)

The wear state detection device according to claim 4, wherein an average thickness of the container ranges from 0.5 mm to 5.0 mm.

### Claim 10 (depends on 4)

The wear state detection device according to claim 4, wherein a ratio of a height Hc of the container with the sensor module inserted to a height Hs of the sensor module ranges from 0.5 to 1.5.

### Claim 11 (depends on 4)

The wear state detection device according to claim 4, wherein
an elongation at break EB of rubber constituting the container ranges from 50% to 900%, and
a modulus at 300% elongation of the rubber constituting the container ranges from 2 MPa to 15 MPa.

### Claim 12 (depends on 4)

The wear state detection device according to claim 4, wherein the container is disposed on an inner side of a ground contact edge in a tire width direction.

### Claim 13 (depends on 1)

The wear state detection device according to claim 1, wherein the element is a piezoelectric element.

### Claim 14 (depends on 2)

The wear state detection device according to claim 2, wherein the determination unit performs at least two determination operations, and conclusively determines the progress condition of the wear of the tread portion based on results of the determination operations.

### Claim 15 (depends on 14)

The wear state detection device according to claim 14, wherein a sensor module comprising at least the element and the voltage detection unit is fixed to a tire inner surface via a container into which the sensor module is inserted.

### Claim 16 (depends on 5)

The wear state detection device according to claim 5, wherein
the container is bonded to the tire inner surface via an adhesive layer, and
as roughness of the tire inner surface, an arithmetic mean height Sa ranges from 0.3 μm to 15.0 μm, and a maximum height Sz ranges from 2.5 μm to 60.0 μm.

### Claim 17 (depends on 16)

The wear state detection device according to claim 16, wherein a width Lc1 of an opening portion of the container and an inner width Lc2 of a bottom surface of the container satisfy a relationship of Lc1<Lc2.

### Claim 18 (depends on 17)

The wear state detection device according to claim 17, wherein a width Lc1 of an opening portion of the container and a maximum width Lsm of the sensor module satisfy a relationship of 0.10≤Lc1/Lsm≤0.95.

### Claim 19 (depends on 18)

The wear state detection device according to claim 18, wherein a width Lc1 of an opening portion of the container, an inner width Lc2 of a bottom surface of the container, a width Ls1 of an upper surface of the sensor module, and a width Ls2 of a lower surface of the sensor module satisfy a relationship of Lc1<Ls1≤Ls2≤Lc2.

### Claim 20 (depends on 19)

The wear state detection device according to claim 19, wherein an average thickness of the container ranges from 0.5 mm to 5.0 mm.