Sumitomo Rubber Industries Limited

Yosuke Matsuda

Hiroaki Ninomiya

Satoshi Iwasaki

Takashi Nishiwaki

Keita Kuroda

A pneumatic tire has a tread portion provided with two crown main groove and two shoulder main grooves and divided into a center land zone, two middle land zones and two shoulder land zones. The middle land zone is provided with middle auxiliary grooves. The shoulder land zone is provided with shoulder axial grooves. The width of the shoulder axial groove at the axially outer end is more than the width of the shoulder axial groove at the axially inner end. Through the shoulder main groove, the shoulder axial grooves are continued to the respective middle auxiliary grooves.

Pneumatic tire

A pneumatic tire is provided in a tread portion with a center land portion which is defined between center main grooves and whose top surface has a certain area and a maximum axial width of 15% to 19% of a tread width. The center land portion is provided with axial sipes and recesses. The recess extends from the center main groove toward the tire equator, and has a depth of 60% to 80% of the depth of the center main groove. The total area of the recesses is 5% to 9% of the area of the above-mentioned top surface. The center land portion is formed as a substantially continuous rib.

A pneumatic tire includes a tread portion provided with a pair of shoulder main grooves adjacent to each tread edge and a pair of center main grooves disposed axially inwardly of the shoulder main grooves to define a pair of middle portions each of which is between the adjacent shoulder main groove and center main groove. The center main grooves have groove widths larger than the groove widths of the shoulder main grooves. The respective middle portions are provided with a plurality of inner middle lug grooves extending axially outwardly of the tire from the center main groove, and a plurality of outer middle lug grooves extending axially inwardly of the tire from the shoulder main groove. The total number of inner middle lug grooves is smaller than the total number of outer middle lug grooves in each middle portion.

A pneumatic tire includes a tread portion provided with a pair of center main grooves to define a center portion therebetween, a pair of shoulder main grooves arranged axially outside the center main grooves to define a middle portion between the center and shoulder main grooves, and middle lateral grooves to divide the middle portion into middle blocks. Each center main groove extends in a zigzag manner including inclined long sides and inclined short sides alternately arranged in a circumferential direction of the tire. The center portion is provided with at least six center sipes within a circumferential region corresponding to a pitch of middle lateral grooves. Each middle block has a circumferential length of 85% to 95% the pitch, and is provided with at least one middle sipe. The number of middle sipe on each middle block is five or less.

Pneumatic tire with tread having center sipes and middle sipes

A pneumatic tire includes a tread portion, a pair of sidewall portions, a pair of bead portions, and a protrusion. The protrusion includes a plurality of longitudinal ribs and a low height part. Each rib has a protruding height of 0.5 to 7.0 mm from the normal outer surface of the sidewall. Each low height part has a protruding height from the normal outer surface of the sidewall that is lower than that of the longitudinal ribs. The sidewall portion with the protrusion has a ratio between a total area of the protrusion projected onto the normal outer surface of the sidewall portion and an area between an outer circumferential line on the sidewall portion passing through a radially outmost point of the protrusion and an inner circumferential line on the sidewall portion passing through a radially innermost point of the protrusion in a range of from 50 to 80%.

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Kobe, Japan

Yosuke Matsuda