Sumitomo Rubber Industries Limited

Takuya Osawa

Ryota Ikeda

Keiji Higuchi

Kenji Ueda

Hiroki Uno

Yuto Ohte

Hiroshi Kikuchi

Teppei Nakamichi

Takashi Hagihara

Tomohisa Kuriyama

Masahiro Nagase

Daichi Takatsuki

Chisato Omori

Shigeki Nishijima

Kentaro Yagyu

Hiroto Takenaka

Takuya Fujimoto

Taiichiro Amemiya

Kensuke Aizawa

Dai Sunazuka

Atsushi Kamigori

Makoto Sonoda

A tire comprises a tread portion comprising circumferential grooves and land portions divided thereby. The land portions include a first shoulder land portion and a first middle land portion adjacent thereto. The first shoulder land portion is provided with first shoulder sipes. The middle land portion is provided with first middle sipes. Each of the first shoulder sipes and the first middle sipes comprises a main portion extending in the tire radial direction, and a widened portion having a width greater than the main portion and opened at the tread surface of the land portion. The opening width of the first shoulder sipe at the tread surface is larger than the opening width of the first middle sipe at the tread surface.

Tire

A tread of a tire can include a cap layer and a base layer. A loss tangent of the cap layer at 30° C. may be not greater than 0.30, and a loss tangent of the base layer at 30° C. may be less than the loss tangent of the cap layer at 30° C. The base layer can be inward of a reference end of the tread in an axial direction A fixing layer can be between the cap layer and a carcass in a radial direction. A first end of the fixing layer can be outward of an end of the base layer in the axial direction, or a position of the first end of the fixing layer can coincide with a position of the end of the base layer in the axial direction. Adhesiveness of the fixing layer can be higher than adhesiveness of the cap layer.

A tire includes a tread portion including four circumferential grooves between outboard and inboard tread edges, and five land portions divided by the circumferential grooves. The circumferential grooves include an inboard shoulder circumferential groove located nearest to the inboard tread edge in the circumferential grooves. The land portions include an inboard shoulder land portion disposed axially outward of the inboard shoulder circumferential groove and having a ground contact surface with the smallest axial width in the land portions. The inboard shoulder land portion is provided with inboard shoulder lateral grooves and inboard shoulder sipes. The inboard shoulder lateral grooves include inner ends away from the inboard shoulder circumferential groove. The inboard shoulder lateral grooves extend axially outward from the inner ends to a location beyond the inboard tread edge. The inboard shoulder sipes extends from the inboard shoulder circumferential groove to a location beyond the inboard tread edge.

A tyre includes a tread portion including first and second land portions. The first middle land portion is provided with first middle lateral grooves traversing the first middle land portion completely. The second middle land portion is provided with second middle lateral grooves traversing the second middle land portion completely. Each of the first middle lateral grooves and the second middle lateral grooves is a curved groove which includes a first convex portion located on a first side with respect to a groove-reference-straight-line that connects both ends of a groove centerline of the curved groove and a second convex portion located on a second side with respect to the groove-reference-straight-line, and a circumferential length of the groove-reference-straight-line of each first middle lateral groove is smaller than a circumferential length of the groove-reference-straight-line of each second middle lateral groove.

Tyre

A tireincludes a tread, a pair of sidewalls, a pair of beads, a carcass, a belt, an inner liner, and a pair of insertion layersdisposed between the carcassand the inner liner. Each insertion layeris disposed between an end of the beltand an end PB of the bead. Each insertion layerhas a volume resistivity of less than 10&#x3a9;&#xb7;cm. A complex elastic modulus of the insertion layeris equivalent to or higher than a complex elastic modulus of the inner liner. A thickness of each sidewallat a maximum width position PW is not greater than 5.0 mm.

The tire has a tread portion axially divided into two shoulder land regions, two middle land regions and one crown land region by two shoulder circumferential grooves and two crown circumferential grooves. The middle land regions are each provided with a single longitudinal sipe, and first and second middle transverse grooves extending from the adjacent shoulder circumferential groove and crown circumferential groove, and terminated without being connected to the longitudinal sipe. The shoulder land regions are each provided with shoulder transverse grooves extending from tread edges and terminated within the respective shoulder land regions.

A pneumatic tire includes a tread having main grooves extending in circumferential direction, and land portions partitioned by the main grooves. The main grooves include a pair of shoulder main grooves on tread edge sides, the land portions include a pair of shoulder ribs between the shoulder grooves and tread edges, rib has shoulder lug grooves extending from tread edge to axial direction inner side and having inner end terminated without reaching shoulder groove, and shoulder sipes extending from shoulder groove to axial direction outer side between adjacent lug grooves in the circumferential direction and having outer end terminated without reaching tread edge, and the ribs are forming such that circumferential direction length of first region between inner ends of sipe and adjacent lug groove is in range of 2 to 4 times circumferential direction length of second region between inner ends of sipe and the other adjacent lug groove.

Pneumatic tire

A tireincludes: a pair of beadsincluding cores; chafers, disposed near the beads, which are brought into contact with a rim; an inner linerdisposed inward of a carcassin an axial direction; and an insulationdisposed between the carcassand the inner linerin the axial direction. The chafersinclude bottom surfacesthat are brought into contact with the rim in portions inward of the coresin a radial direction. The insulationincludes insulation lower portionsdisposed between the coresand the bottom surfacesof the chafersin the radial direction. The inner linerincludes inner liner lower portionsdisposed between the coresand the bottom surfacesof the chafersin the radial direction.

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Kobe, Japan

Takuya Osawa