Sumitomo Rubber Industries Limited

Hiroaki Ninomiya

Tadao Matsumoto

Fumikazu Yamashita

Satoshi Iwasaki

Yasutaka Iwata

Takashi Nishiwaki

Yosuke Matsuda

Yasuaki Kuniyasu

Kentaro Yagyu

Keita Kuroda

Shingo Umekita

A pneumatic tire comprises a carcass which comprises a carcass ply composed of a main portion extending between bead portions and a pair of turned-up portions turned-up around respective bead cores. The bead portion is provided with: a primary bead apex rubber disposed between the carcass-ply main portion and the carcass-ply turned-up portion; an insulation rubber layer extending radially outwardly through between the carcass-ply main portion and the carcass-ply turned-up portion; and a subsidiary bead apex rubber layer disposed on the axially outside of the carcass-ply turned-up portion. The radially outer edge of the insulation rubber layer is located radially outside the radially outer edge of the subsidiary bead apex rubber layer. The complex elastic modulus of the insulation rubber layer is equal to or greater than the complex elastic modulus of the topping rubber of the carcass ply.

Pneumatic tire

A tire comprises a carcass ply extending between bead portions through a tread portion and sidewall portions, and turned up around a bead core in each of the bead portions from the inside to the outside in the tire axial direction so as to form a pair of turnup portions and a main portion therebetween. Each of the bead portions is provided with: a rubber bead apex disposed between the turnup portion and the main portion, and extending radially outwardly from the bead core in a tapered manner; a bead reinforcing rubber layer disposed axially outside the main portion; and an insulation rubber layer disposed between the main portion and the bead reinforcing rubber layer and having a hardness smaller than a hardness of the bead reinforcing rubber layer.

Tire

A tire comprises a tread portion. The tread portionhas a repeated pattern portionin which a plurality of minimum pattern constituent unitsis arranged in a tire circumferential direction. Each of the minimum pattern constituent unitsincludes a center block, a plurality of surrounding blockssurrounding the center block, and dividing grooveseach arranged between adjacent ones of the plurality of the surrounding blocks. The dividing groovesinclude first dividing groovesand second dividing groovesinclined in opposite directions to each other.

A tire includes a tread portion including a first land portion defined between circumferentially extending first and second edges. The first land portion is provided with first and second lateral grooves respectively extending from the first and second edges and terminating within the first land portion and a circumferentially extending first longitudinal narrow groove in communication with the first and second lateral grooves. Each of the first and second lateral grooves includes a wide-width portion and a narrow-width portion. The wide-width portion of each of the first lateral grooves extends from the first edge and the wide-width portion of each of the second lateral grooves extends from the second edge. The first longitudinal narrow groove passes through the narrow-width portion of each of the first and second lateral grooves without passing through the wide-width portion of each of the first and second lateral grooves.

In the tire, fillersare layered over clinchesin portions outward of a carcassin the axial direction. A carcass plyis turned up around cores. Turned-up portionsare disposed between the fillersand apexes. Each clinchhas a maximum thickness Tcx that is measured along a line normal to an inner surface, in the axial direction, of the clinch. A ratio of a thickness Tfof the fillerto a sum of the thickness Tfand the thickness Tcx is greater than or equal to 0.1 and not greater than 0.6. A percentage of a complex elastic modulus E*f of the fillerrelative to a complex elastic modulus E*a of the apexis greater than or equal to 70% and not greater than 125%.

A pneumatic tire comprises a tread portionprovided with at least one circumferentially continuously extending main groove. The main groovehas a zigzag periodical pattern formed by circumferentially repeatedly arranging a first oblique segmentand a second oblique segmentas a repeating unit which define one zigzag pitch. The first oblique segmentextends without being bent, and the second oblique segmentextends in a bent manner.

Tire for automobile

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.

A pneumatic tire includes a tread portion provided with a pair of center main grooves and a pair of shoulder main grooves to define a center portion, a pair of middle portions, and a pair of shoulder portions. The shoulder main grooves extend in a trapezoid wave manner that includes a circumferentially extending axially outer part, an axially inner part arranged axially inwardly of the axially outer part, and an inclined part connecting between the axially outer and inner parts. The shoulder portion is provided with shoulder lateral grooves extending from the shoulder main groove to a tread edge to define a plurality of shoulder blocks. Each shoulder lateral groove has its axially inner end connected to the axially outer part of the shoulder main groove so as to include an outer corner point between the axially outer part and the inclined part.

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Kobe, Japan

Hiroaki Ninomiya