# US 12,214,625 B2 · Wear-condition-sensing device

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- Number: US 12,214,625 B2
- Document ID: US12214625B2
- Status: Granted
- Kind: B2
- Application number: 17/759,321
- Filed: 2021-01-15
- Published: 2023-04-06
- 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/US12214625B2

## CPC

- B60C 11/243: {Tread wear sensors, e.g. electronic sensors}
- B60C 11/246: {Tread wear monitoring systems}
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES

## Abstract

A wear-condition-sensing 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 storage area configured to store waveform data over time of the voltage detected by the voltage detection unit, a calculation unit configured to calculate an index value of voltage change based on the waveform data stored in the storage area, and a determination unit configured to determine a progress condition of wear of the tread portion by comparing the index value calculated by the calculation unit with reference information.

## Claims

### Claim 1

A wear-condition-sensing 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 integrally store waveform data over time of the voltage detected by the voltage detection unit together with the vehicle speed or the rotation speed detected by the detection unit;
a calculation unit configured to calculate an index value of voltage change based on the waveform data in a predetermined speed range stored in the storage area; and
a determination unit configured to determine a progress condition of wear of the tread portion by comparing the index value calculated by the calculation unit with reference information corresponding to a predetermined speed range to determine a progress state of wear of the tread portion,
the predetermined speed range being a range of ±5 km/h from any speed within a range of 30 km/h to 60 km/h.

### Claim 2 (depends on 1)

The wear-condition-sensing 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 index value obtained based on the waveform data on a basis of the air pressure detected by the air pressure detection unit.

### Claim 3 (depends on 1)

The wear-condition-sensing device according to claim 1, wherein the calculation unit calculates a peak amplitude value between a maximum value and a minimum value in the waveform data as the index value of voltage change.

### Claim 4 (depends on 1)

The wear-condition-sensing 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 5 (depends on 1)

The wear-condition-sensing 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 6 (depends on 5)

The wear-condition-sensing 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 7 (depends on 5)

The wear-condition-sensing device according to claim 5, 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 8 (depends on 5)

The wear-condition-sensing device according to claim 5, 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 9 (depends on 5)

The wear-condition-sensing device according to claim 5, 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 10 (depends on 5)

The wear-condition-sensing device according to claim 5, wherein an average thickness of the container ranges from 0.5 mm to 5.0 mm.

### Claim 11 (depends on 5)

The wear-condition-sensing device according to claim 5, 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 12 (depends on 5)

The wear-condition-sensing device according to claim 5, 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 13 (depends on 5)

The wear-condition-sensing device according to claim 5, wherein the container is disposed on an inner side of a ground contact edge in a tire width direction.

### Claim 14 (depends on 1)

The wear-condition-sensing device according to claim 1, wherein the element is a piezoelectric element.

### Claim 15 (depends on 1)

The wear-condition-sensing device according to claim 1, wherein the reference information is an arbitrary rate of change with respect to the index value of voltage change when the tire was new.

### Claim 16

A wear-condition-sensing 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 integrally 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 an index value of voltage change based on the waveform data in a predetermined speed range stored in the storage area; and
a determination unit configured to determine a progress condition of wear of the tread portion by comparing the index value calculated by the calculation unit with reference information corresponding to a predetermined speed range to determine a progress state of wear of the tread portion,
the predetermined speed range being a range of ±5 km/h from any speed within a range of 30 km/h to 60 km/h, and the reference information being an arbitrary rate of change with respect to the index value of voltage change when the tire was new, 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, and
a width Lc1 of an opening portion of the container and a maximum width Lsm of the sensor module satisfy a relationship of 0.15≤Lc1/Lsm≤0.90.