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JP-7855877-B2 - tire

JP7855877B2JP 7855877 B2JP7855877 B2JP 7855877B2JP-7855877-B2

Inventors

  • 岡 健太朗
  • 阿部 頌太朗
  • 早苗 隆平
  • 中島 翔

Assignees

  • 住友ゴム工業株式会社

Dates

Publication Date
20260511
Application Date
20220314

Claims (9)

  1. A tire having a tread portion with a specified direction of rotation, The tread portion includes a first tread end, a plurality of first inclined grooves extending at least from the first tread end toward the tire equator toward the leading side in the rotational direction, and a plurality of first land portions divided by the plurality of first inclined grooves. Each of the plurality of first inclined grooves includes a first groove wall on the leading side in the rotational direction and a second groove wall on the trailing side in the rotational direction. A first chamfered portion is formed on the first groove wall. The second groove wall has a second chamfered portion formed therein. In a cross-section perpendicular to the groove centerline of the first inclined groove, the chamfering area S1 of the first chamfered portion is larger than the chamfering area S2 of the second chamfered portion. In a region of 50% or more of the total length of the first inclined groove, the chamfer area S1 is larger than the chamfer area S2 . tire.
  2. The tire according to claim 1, wherein the chamfered area S1 is 1.1 times or more the chamfered area S2.
  3. The tire according to claim 1 or 2, wherein the chamfered area S1 is 1.5 times or less the chamfered area S2.
  4. The tire according to any one of claims 1 to 3, wherein the chamfered area S1 of the first chamfered portion increases toward the outward direction in the tire axial direction.
  5. The tire according to any one of claims 1 to 4, wherein the chamfered area S2 of the second chamfered portion increases toward the outward direction in the tire axial direction.
  6. The tire according to any one of claims 1 to 5 , wherein the chamfered area S1 is larger than the chamfered area S2 over the entirety of the first inclined groove .
  7. The tire according to any one of claims 1 to 6, wherein the angle of the first inclined groove with respect to the tire circumferential direction increases toward the outward direction in the tire axial direction .
  8. The tire according to any one of claims 1 to 7, wherein the angle of the first inclined groove at the first tread end with respect to the tire circumferential direction is 80 to 90° .
  9. The first inclined groove includes the inner end on the tire equator side, The tire according to any one of claims 1 to 8, wherein the angle of the first inclined groove at the inner end with respect to the tire circumferential direction is 30 to 70° .

Description

This disclosure relates to tires. Patent Document 1 below proposes a tire in which the tread portion is provided with multiple inclined grooves that extend diagonally from one of the first tread ends in the axial direction of the tire toward the tire equator. Japanese Patent Publication No. 2019-156025 This is an exploded view of the tread portion of a tire according to one embodiment of the present disclosure.This is an enlarged view of the first inclined trench and the first land area in Figure 1.This is a cross-sectional view taken along line A-A in Figure 2.Figure 3 is an enlarged view of the first and second chamfered sections.This is an enlarged cross-sectional view showing the state of a conventional inclined groove when it is in contact with the ground. The following describes one embodiment of this disclosure based on the drawings. Figure 1 is an exploded view of the tread portion 2 of the tire (hereinafter sometimes simply referred to as "tire") 1 of this embodiment. As shown in Figure 1, the tire 1 of this embodiment is preferably, for example, a passenger car tire. However, the tire 1 of this disclosure is not limited to this form, and may also be, for example, a heavy-duty tire. The tire 1 of this disclosure has a tread portion 2 with a specified rotation direction R. The rotation direction R is indicated, for example, by letters or symbols on the sidewall portion (not shown). The tread portion 2 of the tire 1 in this embodiment includes a first tread end T1 and a second tread end T2. In the figures of this specification, the tread end on the left side of the tire equator C is the first tread end T1, and the tread end on the right side of the tire equator C is the second tread end T2. The tread portion 2 includes a first tread portion 2A located on the first tread end T1 side of the tire equator C, and a second tread portion 2B located on the second tread end T2 side of the tire equator C. The first tread portion 2A and the second tread portion 2B are substantially symmetrical with respect to the tire equator C, except for a point of displacement in the circumferential direction of the tire. Therefore, each component of the first tread portion 2A can be applied to the second tread portion 2B. The first tread edge T1 and the second tread edge T2 are the outermost contact points in the tire's axial direction when tire 1 in its normal state is loaded with 60% of its normal load, has a camber angle of 0°, and is in contact with a flat surface. "Normal condition" refers to the state in the case of pneumatic tires for which various standards are defined, where the tire is mounted on a normal rim, filled to the normal internal pressure, and under no load. For tires for which various standards are not defined, or for non-pneumatic tires, the normal condition refers to the standard operating condition according to the tire's intended use, and is under no load. Unless otherwise specified in this specification, the dimensions of each part of the tire are values measured under the normal condition. Furthermore, unless otherwise specified in this specification, known methods may be appropriately applied to the measurement methods of the aforementioned dimensions and material composition. A "standard rim" is the rim specified for each tire within the tire's standardization system, including the standard on which the tire is based. For example, it would be a "standard rim" for JATMA, a "design rim" for TRA, or a "measuring rim" for ETRTO. "Regular internal pressure" refers to the air pressure specified for each tire within the tire standard system, including the standard on which the tire is based. For JATMA, this is the "maximum air pressure"; for TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES"; and for ETRTO, it is the "INFLATION PRESSURE." "Regular load" refers to the load specified for each tire within the standard system, including the standard on which the tire is based, for pneumatic tires with various defined standards. For example, it's the "maximum load capacity" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "LOAD CAPACITY" for ETRTO. For tires without defined standards, "regular load" refers to the maximum load applicable to the tire's use, in accordance with the aforementioned standards. The tread portion 2 includes a plurality of first inclined grooves 5 and a plurality of first land portions 7. The first inclined grooves 5 extend at least from the first tread end T1 toward the tire equator C, inclined toward the leading side in the rotational direction R (the downward side in the figures herein). In this embodiment, the first inclined grooves 5 are interrupted before reaching the tire equator C. The first inclined grooves 5 may, for example, cross the tire equator C. The first land portion 7 is divided into the first inclined grooves 5. The tread portion 2 of this embodi