The Yokohama Rubber Co., Ltd.

Toyoaki Endo

Kenichi Sato

Daigen Tsunekawa

Yoshiaki Hashimura

Jun Matsuda

Yuichi Hara

Yoshifumi Koishikawa

Hideki Seto

Takashi Shibai

A pneumatic tire includes a land portion defined by two circumferential main grooves extending in the circumferential direction, lug grooves in the land portion, and a sipe between adjacent lug grooves. An outer side edge of the land portion in the width direction has a zigzag shape, and an inner side edge of the land portion in the width direction has a straight shape. The sipe extends continuously from the outer side edge to the inner side edge, and the sipe has a Z-shape with two bent portions, and a ratio of a distance in the width direction between a bent portion closer to a center line passing through a midpoint position of the land portion in the width direction and the center line to a width of the land portion in the width direction being 0 to 0.40.

Pneumatic tire

A tread portion of a pneumatic tire includes: an intermediate land portion being delimited by an inner circumferential main groove and an outer circumferential main groove on one side in a tire lateral direction across a tire center line as a boundary; and a side land portion adjoining the outer circumferential main groove and being provided outward of the outer circumferential main groove in the tire lateral direction. At least one land portion of the intermediate land portion and the side land portion has a swelling profile line. In a region of the land portion, a composite sipe is provided. In the composite sipe, a first sipe extending linearly in a sipe depth direction and a second sipe (S) extending in a wave manner in the sipe depth direction are connected. The second sipe in the composite sipe is disposed so as to be connected to the outer circumferential main groove.

A tread pattern of a pneumatic tire includes two or more circumferential main grooves in a half region demarcated by the equatorial plane, and land portions defined by the circumferential main grooves. A center land portion closest among the land portions to the equatorial plane includes a center sipe extending in the width direction, the center sipe is a composite sipe including a two-dimensional portion and three-dimensional portions provided on both sides of the two-dimensional portion in the width direction, a middle land portion that is adjacent to an outer side of the center land portion in the width direction includes a middle sipe extending in the width direction, and the middle sipe is a composite sipe comprising a two-dimensional portion provided on an inner side in the width direction and a three-dimensional portion provided on an outer side of the two-dimensional portion in the width direction.

A tread pattern of a pneumatic tire includes three or more circumferential main grooves extending in a tire circumferential direction, a plurality of lug grooves provided in a land portion defined by two circumferential main grooves, and a sipe provided between adjacent lug grooves. The sipe is a composite sipe having a two-dimensional portion and a three-dimensional portion. Among open ends on both sides of the lug groove, an open end on an identical side to an end portion of the sipe at which the two-dimensional portion is provided is provided with a raised bottom portion.

A tread pattern of a pneumatic tire includes circumferential main grooves, a land portion defined by the circumferential main grooves in the lateral direction, and sipes at intervals in a circumferential direction, the sipes connecting the circumferential main grooves with each other. Each of the sipes has a peak-like shape protruding to a first side in the circumferential direction. When, in a profile cross-section of the tread portion taken along the lateral direction, an arc passing through two land portion edge points at which a tread surface of the land portion is connected with groove wall surfaces of the circumferential main grooves and having a center point positioned on the equator line is set to a standard profile line, a profile line formed by the tread surface of the land portion is a swelling profile line protruding outward of the standard profile line in a radial direction.

Automobile tire

A pneumatic tire which uses, as an inner liner layer, a laminated sheet obtained by laminating an air permeation preventing layer, made of any one of a thermoplastic resin and a thermoplastic elastomer composition containing a blend of the thermoplastic resin and an elastomer, and a tie rubber layer, and which has high durability to prevent development of a crack in the tie rubber layer that occurs around a splice portion of the laminated sheet after the tire starts to be used. In the pneumatic tire, a sagged portion is formed by a concavo-convex structure in the air permeation preventing layer at least between points P and Q in a shape that a length La of a straight line connecting points P and Q and a length Lb of the air permeation preventing layer actually passing through points P and Q satisfy a relationship of (1.03&#xd7;La)&#x2266;Lb&#x2266;(1.5&#xd7;La).

Disclosed is a pneumatic tire comprising (A) reinforcing layer comprising a plurality of reinforcing cords or wires coated with a rubber composition, wherein (B) a film layer, (C) an elastomer layer, and (D) a film layer comprising ethylene-vinyl alcohol copolymer are sequentially laminated on the tire inner surface side of reinforcing layer (A), and the product of Young's modulus Eb (MPa) and thickness Gb (mm) of film layer (B) is equal to or more than 5 kN/m, wherein the reinforcing layer having improved durability.

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Hiratsuka, Japan

Toyoaki Endo