Sumitomo Rubber Industries Limited

Koichi Nakajima

Masayuki Fujita

Yoshifumi Kawagoe

Yuichi Ishigaki

Tetsuya Sakaguchi

Naoki Ishida

Hiroshi Yamaoka

Toshiaki Suzuki

Shintaro Tomita

Kazuma Mori

Sho Nakajima

Mitsuhiro Nishino

Kohei Ikeda

Yu Hashimoto

A tire comprises a tread portion including a land portion. In the land portion, closed sipes are arranged in a tire axial direction. Each of the closed sipes includes a first end, a second end, a first sipe piece extending in the tire axial direction on a first end side, a second sipe piece extending in the tire axial direction on a second end side, and a third sipe piece inclined with respect to the tire axial direction and positioned between the first sipe piece and the second sipe piece. The closed sipes arranged in the tire axial direction overlap each other in the tire axial direction.

Tire

A tire includes a tread portion including at least one circumferential groove extending continuously in a tire circumferential direction. The at least one circumferential groove includes a groove bottom having a plurality of protrusions projecting in a tire radial direction. Each of the plurality of protrusions has a longitudinally elongated shape with a width in a tire axial direction and a length in the tire circumferential direction that is greater than the width. Each of the plurality of protrusions includes a tapered portion whose width decreases in the tire circumferential direction.

A tire is provided with blocks in a tread portion. Each of the blocks has a block wall surface provided with first recesses. Each of the first recesses extends across a block ground contacting surface and the block wall surface. Each of the first recesses has a triangular ground contacting surface opening on the block ground contacting surface and a triangular wall surface opening on the block wall surface. The wall surface opening has a first end terminating without reaching a groove bottom of one of grooves demarcating the each of the blocks.

A tyre includes a tread portion including a tread surface which is provided with grooves. At least one of the grooves includes a widening-width portion at least partially. The widening-width portion includes a first groove portion extending inwardly in a tyre radial direction from the tread surface, and a second groove portion located inwardly in the tyre radial direction of the first groove portion and having a groove width greater than that of the first groove portion.

Tyre

A tire includes a pair of sidewall portions. An outer surface of at least one of the sidewall portions includes at least one concave mark recessed from a reference surface. The or each concave mark includes a bottom surface and an inner wall surface. The bottom surface includes a peripheral region and a main region. The peripheral region includes a shadow region and a non-shadow region. The shadow region and the non-shadow region are each formed with an uneven surface provided with minute protuberances. A width of the uneven surface of the non-shadow region measured in a direction perpendicular to a contour of the or each concave mark is smaller than a width of the uneven surface of the shadow region measured in a direction perpendicular to the contour.

Tire for automobile

Provided is a tire that allows reduction of uneven wear such as heel-and-toe wear around a plurality of closed sipes. The tire includes a tread portion. A plurality of closed sipesare aligned in a tire axial direction in a land portionof the tread portion. Each of the closed sipesincludes a sipe bottom, a first endand a second end, a first sipe piece, a second sipe piece, a third sipe piece, and at least one tie bar. The closed sipesaligned in the tire axial direction overlap each other in the tire axial direction and a tire circumferential direction. The tie barincludes a first tie bar. A center, in a sipe length direction, of the first tie baris disposed closer to a first intersecting portionthan a center, in a length direction, of the first sipe pieceis. A distance from the first tie barto the first intersecting portionis not greater than 25% of a length of the first sipe piece

A tire that can achieve both desired visibility and design properties of a mark provided on a sidewall portion is provided. A tire has a mark provided on a surface of a sidewall portion so as to be raised from the surface. The mark includes a curved surface portion curved so as to project in a direction substantially perpendicular to the surface of the sidewall portion, and a flat surface portion provided on at least one side in a tire circumferential direction of the curved surface portion, and a raised height h of the flat surface portion from the surface gradually decreases with increasing distance in the tire circumferential direction from the curved surface portion.

A tread portion includes a groove having first and second groove walls opposing each other, at least one first recess formed by partially recessing the first groove wall, and at least one second recess formed by partially recessing the second groove wall. A depth of each of the first and second recess from a ground contact surface is less than a groove depth of the groove. The first recess includes a first opening disposed at the first groove wall, and a first end portion extending substantially parallel to the first opening at a position farthest from the first opening. The second recess includes a second opening disposed at the second groove wall, and a second end portion extending substantially parallel to the second opening at a position farthest from the second opening. The first and second end portions are disposed so as not to oppose each other through the groove.

A tire includes a tread portion that includes a first circumferential groove and a first land portion. A groove bottom portion of the first circumferential groove includes a groove bottom reference surface and a plurality of projections projecting outwardly in a tire radial direction from the groove bottom reference surface. The first land portion has at least one first lateral groove extending from the first circumferential groove and terminating within the first land portion. In a tread plan view, an entirety of a first lateral groove extension region obtained by extending a connection portion of the first lateral groove at the first circumferential groove to the groove bottom portion of the first circumferential groove so as to be parallel to a tire axial direction is formed on the groove bottom reference surface.

A lateral groove provided in a tread portion has: an opening formed in a tread surface; a minimum portion having the smallest groove width, positioned radially inside the opening; and a maximum portion having the largest groove width, positioned radially inside the minimum portion. The width of the opening increases toward the outside in the tire axial direction.

A tyre includes a tread portion provided with a circumferential groove and a lateral groove. The at least one lateral groove includes a connected portion connected to the circumferential groove. The circumferential groove includes a groove bottom provided with groove bottom protruding portions protruding outwardly in the tyre radial direction. Each groove bottom protruding portion includes a first surface portion extending in the tyre radial direction and facing a first circumferential direction, and a second surface portion arranged on a second circumferential direction opposite to the first circumferential direction and extending at a larger angle with respect to the tyre radial direction than that of the first surface portion. In a tread plan view, at least a part of the groove bottom protruding portions is located in a lateral-groove extended region in which the connected portion is extended into the circumferential groove along the tyre axial direction.

A tyre includes a tread portion having a tread surface being provided with a plurality of lateral grooves extending in a tyre axial direction. In a cross-sectional view perpendicular to a longitudinal direction of the at least one of the plurality of lateral grooves, the at least one of the plurality of lateral grooves includes a pair of groove walls and a groove bottom. At least one of the pair of groove walls includes a serrated portion including first surfaces and second surfaces that are arranged alternately. Each first surface is inclined outwardly in a groove width direction toward the groove bottom and has a radially inner end thereof, and each second surface extends substantially parallel with the tread surface from the radially inner end of a respective one of the first surfaces toward a groove centerline of the at least one of the plurality of lateral grooves.

A tireincludes a tread portionprovided with a block. A block corner portionof the blockhas a stepped chamfered portionformed therein in which a block height decreases stepwise from a tread surfacetoward a top portion. The stepped chamfered portionincludes upper surfacesparallel to the tread surface, and step corner portionseach formed so as to protrude toward a block outer side as a result of the upper surfaceand a vertical surfaceor the vertical surfaceand the tread surfaceintersecting each other. An angle &#x3b8;between the tread surfaceand a virtual straight line nconnecting the step corner portionsin a vertical cross-sectional view, of the block corner portion, passing through the top portionis 10 to 40 degrees.

A tire can include a block having a recess. The recess can include a first opening on a tread side and a second opening on a side wall face side. The first opening can include a pair of first edges extending from a first vertex to the side wall face side so as to form a V-shaped edge on the tread. The second opening can include a pair of second edges that can extend from a second vertex on the side wall face, and can be connected to the pair of first edges at intersection points. One of the pair of second edges can include a second edge body that can extend on a straight line from the second vertex to the intersection point, and a second edge subsidiary portion that can be bent so as to widen the second opening.

Growing community of inventors

Hyogo, Japan

Koichi Nakajima