Sumitomo Rubber Industries Limited

Satoko Tsujibayashi

Yoshiyuki Takada

Satoshi Tanaka

A heavy duty tire comprises a tread portion having circumferential grooves and land portions. The circumferential grooves include two shoulder circumferential grooves and a crown circumferential groove. The land portions include two of shoulder land portions and two crown land portions. The width Wof the shoulder land portion is 17% to 28% of the tread width TW. The crown land portion is divided by crown shallow groove into crown blocks. The groove depth of the crown shallow groove is smaller than the groove depth of the crown circumferential groove. The groove bottom of the crown shallow groove is provided with a groove bottom sipe. The ground contacting top surface of the crown block is hexagonal, and the maximum circumferential dimension is 100% to 200% of the maximum axial dimension.

Heavy duty tire

A tire includes a tread portion being provided with circumferential grooves extending continuously in a zigzag manner. One of the circumferential grooves includes first inclined elements inclined in a first direction with respect to the tire circumferential direction, second inclined elements inclined in a second direction opposite to the first direction with respect to the tire circumferential direction, and intersections where the first inclined elements and second inclined elements intersect. Each of the first inclined elements and the second inclined elements is provided with at least one first protrusion that projects outwardly in a tire radial direction from the groove bottom and connects the pair of groove walls. At least one of the intersections is provided with a second protrusion that projects outwardly in the tire radial direction from the groove bottom and is separated from the pair of groove walls.

Tire

Tire for automobile

A heavy duty pneumatic tire in which occurrence of uneven wear is inhibited is provided. In the tire, each shoulder land portion includes a groove wall portion forming a wall of a shoulder circumferential groove, and a cap portion located outward of the groove wall portion in an axial direction. A wear resistance index of the groove wall portion is lower than a wear resistance index of the cap portion. A ratio of a distance in the axial direction from an outer edge of the shoulder circumferential groove to a boundary between the groove wall portion and the cap portion on an outer surface of the shoulder land portion, to a width in the axial direction of the shoulder land portion, is not less than 20% and not greater than 30%.

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Hyogo, Japan

Satoko Tsujibayashi