Bridgestone Corporation

Shun Oogane

Yuki Kawakami

Kazutaka Matsuzawa

An object of the present invention is to provide a pneumatic tire capable of facilitating heat dissipation of a tread portion thereof to lower temperature at the tread portion. Specifically, the present invention provides a pneumatic tire having in a tread surface at least one circumferential groove extending in the tire circumferential direction and plural lateral grooves, the lateral grooves each opening to the circumferential groove, having a wider groove width than the circumferential groove and extending to be inclined with respect to the tire circumferential direction, comprising: a recessed portion formed in a groove wall, facing the corresponding lateral groove, of the circumferential groove; and at least one projecting portion formed at a groove bottom of the circumferential groove between the recessed portions adjacent to each other in the tire circumferential direction.

Pneumatic tire

In a pneumatic tire, a side surface (), on a buttress portion () side, of a land portion block () is inclined to the inside of the land portion block (). The length (Lb), in a tread width direction, of an and portion (B) of the land portion block () is smaller than the length (La), in the tread width direction, of an end portion (A). The end portion (B) is located at a rear side in a rotational direction (R) in which the pneumatic tire () installed on a vehicle rotates when the vehicle moves forward, and the end portion (A) is located at a front side in the rotational direction (R).

Heavy duty tire

An of object of the present invention is to provide a pneumatic tire which exhibits improved durability of a bead portion due to further suppressing compression strain at a carcass ply fold-up portion and, in particular, suppressing fatigue fracture at the carcass ply fold-up portion. Cord distance between the carcass main body and the carcass ply fold-up portion gradually decreases from the bead core toward the outer side in the tire radial direction to reach the minimum value a, then gradually increases to the maximum value b; provided that height Hof a flange of an application rim, measured from a base line of the application rim in a state where the tire is assembled with the rim and inflated at a prescribed internal pressure, is 1, heights Hand Hmeasured from the base line to the positions on the carcass main body corresponding to the minimum and the maximum values, respectively, and the maximum height Hof the tire satisfy relationship formulae below,H&#x2267;8.001.26&#x2266;H&#x2266;2.142.43&#x2266;H&#x2266;3.75; anda value of ratio (b/a) of the maximum value b with respect to the minimum value a of distance between cords of the carcass main body and the carcass ply fold-up portion exceeds 1.00.

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Kodaira, Japan

Shun Oogane