The Yokohama Rubber Co., Ltd.

Hideki Hamanaka

Yukihito Yamaguchi

Risa Tauchi

Toshiyuki Sato

Shoei Kakuta

Koichi Kotoku

Kotaro Iwabuchi

Koshi Iga

Daisen Hayashi

Takamasa Motomitsu

Kouichi Koutoku

Tsuyoshi Kunugi

Kohshi Iga

Mitsuru Manabe

A pneumatic tire comprises a carcass layer, a belt layer radially outward of the carcass layer, and a tread rubber radially outward of the belt layer. The belt layer is formed by laminating a large angle belt having a belt-cord angle of 45°-70°, a pair of cross belts having belt cord angles of 10°-45° with opposite sign belt cord angles, and a reinforcing layer having a belt cord angle satisfying ±5° relative to a circumferential direction. A reinforcing layer width Ws and a carcass cross-sectional width Wca satisfy 0.60≤Ws/Wca≤0.70. A wider cross belt width Wbof the pair of cross belts and the carcass width Wca satisfy 0.79≤Wb/Wca≤0.89. Relationships 0.79≤Wb/Wca≤0.84 and either 0.82≤TW/Wca≤0.92 or 0.79≤TW/SW≤0.89 are satisfied, where TW is a tread width and SW is a total tire width.

Pneumatic tire

A pneumatic tire comprises a carcass layer, a belt layer radially outward of the carcass layer, and a tread rubber radially outward of the belt layer. A belt cord angle of a belt layer large angle belt is 45-70°, opposite sign belt cord angles of cross belts are 10-45°, and a reinforcing layer belt cord angle is within ±5° of a circumferential direction. A reinforcing layer width Ws and a carcass cross-sectional width Wca satisfy 0.60≤Ws/Wca≤0.70. The reinforcing layer is radially outward of the cross belts which are radially outward of the large angle belt. A wider cross belt width Wbof the pair and Wca satisfy 0.79≤Wb/Wca≤0.89. Wb2 and Wca satisfy 0.79≤Wb/Wca≤0.89. Relationships 0.79≤Wb/Wca≤0.84 and either 0.82≤TW/Wca≤0.92 or 0.79≤TW/SW≤0.89 are satisfied, where TW is a tread width and SW is a total tire width.

Automobile tire

A pneumatic tire includes two circumferential main grooves disposed in an inner half of a tread developed width in a tire lateral direction; shoulder lug grooves that divide shoulder land portions into shoulder block portions and that each include a see-through portion in the tire lateral direction; center lug grooves dividing a center land portion into a plurality of center block portions; and center sipes having both ends terminated in the center block portions. The center sipe includes at least two sipe portions having different angles via at least one bent portion. An angle &#x3b8;of at least one sipe portion with respect to a tire equator line satisfies 0&#xb0;&#x2264;&#x3b8;&#x2264;15&#xb0;, and an angle &#x3b8;of at least the other sipe portion with respect to the tire equator line satisfies 35&#xb0;&#x2264;&#x3b8;&#x2264;60&#xb0;.

A pneumatic tire comprises a carcass layer, a belt layer disposed on an outer side of the carcass layer in a tire radial direction, and a tread rubber disposed on the outer side of the belt layer in the tire radial direction. The belt layer formed by laminating an angle belt having a belt angle &#x2265;45&#xb0; and &#x2264;70&#xb0; in absolute values, a pair of cross belts, having belt angles of &#x2265;10&#xb0; and &#x2264;45&#xb0; in absolute values and having belt angles of mutually opposite signs, and a circumferential reinforcing layer having a belt angle within a range of &#xb1;5&#xb0; with respect to a tire circumferential direction. A tread width TW and a cross-sectional width Wca of the carcass layer have a relationship such that 0.82&#x2264;TW/Wca&#x2264;0.92. A width Ws of the circumferential reinforcing layer and a cross-sectional width Wca of the carcass layer such that 0.60&#x2264;Ws/Wca&#x2264;0.70.

A pneumatic tire includes at least four circumferential main grooves extending in a tire circumferential direction and at least five land portions defined by the at least four circumferential main grooves. A center land portion includes a plurality of center lug grooves extending through the center land portion in a tire lateral direction and disposed at predetermined intervals in the tire circumferential direction, and a plurality of center blocks that are defined by the plurality of center lug grooves. The center blocks each include a narrow shallow groove that extends through the center block in the tire lateral direction and that remains open when the tire comes into contact with the ground.

A pneumatic tire includes: a rib defined by a circumferential main groove; circumferential sipes formed in the rib at intervals in the circumferential direction; rib edge sipes formed in the rib aligning in the circumferential direction, each of the rib edge sipes terminating in the rib opening to the circumferential main groove; and first and second narrow grooves extending in the circumferential direction, each of the first and second narrow grooves having a groove depth shallower than depths of the circumferential sipes and the rib edge sipes, the first narrow grooves having ends connected to one of the circumferential sipes adjacent to each other in the circumferential direction and the second narrow grooves each including an inner connecting portion connected to one of the first narrow shallow grooves and including an outer connecting portion connected to one of the rib edge sipes.

A pneumatic tire includes a plurality of center lug grooves disposed at intervals in a tire circumferential direction that extend crossing a tire equator line and include a first groove turning portion and a second groove turning portion; a plurality of shoulder lug grooves disposed in the intervals between the plurality of center lug grooves in the tire circumferential direction extending outward in the tire width direction, an inner end in the tire width direction being disposed outward of an end of the center lug groove in the tire width direction; a pair of circumferential main grooves to which the ends of the center lug grooves and the inner ends of the plurality of shoulder lug grooves in the tire width direction alternately connect; and a circumferential secondary groove disposed around the entire circumference of the pneumatic tire with a wave-like shape.

Growing community of inventors

Hiratsuka, Japan

Hideki Hamanaka