The Yokohama Rubber Co., Ltd.

Masatoshi Shimizu

Yuji Minami

Masatoshi Kuriyama

Masaki Sato

Masatoshi Kuwajima

Takahisa Murata

Shinya Harikae

Provided is a tire having a cross-sectional height (SH) ranging from 50 mm to 150 mm, in an unloaded state where the tire is mounted on a specified rim and inflated to a specified internal pressure, an opening distance (A) between the tire and a rim flange on a perpendicular line drawn from an outermost point of the rim flange in a radial direction to an outer surface of the tire with respect to the cross-sectional height (SH) satisfies a relationship 0.01≤A/SH≤0.16 and a projection amount (W) corresponding to one half of a difference between a total width of the tire and a rim width of the specified rim satisfy a relationship 0.03≤A/W≤1.60.

Tire

In a tread portion of a pneumatic tire, an average lateral groove width Lc of a center region is obtained by dividing the groove area of lateral grooves in the center region by a circumferential length of the center region, and an average lateral groove width Lsh of a shoulder region is obtained by dividing the groove area of lateral grooves in the shoulder region by a circumferential length of the shoulder region. A relationship between a tire average thickness Gc of the center region and a tire average thickness Gsh in the shoulder region satisfies 1.05≤(Gc/Gsh)≤1.35, a relationship between the average lateral groove width Lc of the center region and the tire average thickness Gc in the center region satisfies 0.07≤(Lc/Gc)≤0.12, and a relationship between the average lateral groove width Lsh of the shoulder region and the tire average thickness Gsh in the shoulder region satisfies 0.17≤(Lsh/Gsh)≤0.26.

Pneumatic tire

In a pneumatic tire, a tread portion includes a main groove extending in a circumferential direction, and land portions defined by the main groove. A center region is a region where a center land portion included in the land portions is closest to a tire equatorial plane. Shoulder regions are each a region between a position corresponding to 85% of a width of the belt layer in a lateral direction and an end portion of the belt layer in the lateral direction, and intermediate regions are each a region between the center region and a corresponding one of the shoulder regions. A relationship among a tire average thickness Gc in the center region, a tire average thickness Gsh in the shoulder regions, and a tire average thickness Gm in the intermediate regions is within a range of 1.05≤(Gc/Gsh)≤1.35 and satisfies Gc≥Gm>Gsh.

In a pneumatic tire, a carcass layer is between bead portions, a bead core is in each bead portion, a reinforcement layer is on an outer side of the carcass layer, and a tread rubber layer is on the outer side of the reinforcement layer. A pair of first boundary lines passes through an intersection of an extension of a side arc forming a tread profile and an extension of a shoulder arc and orthogonal to a tire inner surface, a pair of second boundary lines passes through a rim check line and orthogonal to the tire inner surface, first to third regions are defined which have cross sectional areas of SA, SB, and SC, respectively, and the first to third regions respectively have lengths of a, b, and c along the tire inner surface such that 7.5&#x2264;SA/a&#x2264;11.5 and 2.0&#x2264;SB/b&#x2264;6.0 are satisfied.

Pneumatic tire for passenger vehicle

A pneumatic tire includes, in a tread portion, main grooves extending in a circumferential direction; ribs defined by the main grooves; at least one rib comprising sipes extending in a lateral direction; the sipes comprising a chamfered sipe with a chamfer portion provided on at least one edge, and a non-chamfered sipe with no chamfer portion provided on an edge; the chamfered sipe comprising one end portion terminating in the at least one rib and another end portion communicating with one of the main grooves located on either side of the at least one rib; a plurality of the chamfered sipes communicating with one of the main grooves located on either side of the at least one rib being alternately disposed in the circumferential direction; and the non-chamfered sipe being disposed close to the chamfered sipe on at least one side in the circumferential direction.

Automobile tire

A pneumatic tire includes a tread portion, sidewall portions, bead portions, and has at least one carcass layer disposed between the pair of bead portions. The ratio SW/OD between the total tire width SW and the tire external diameter OD satisfies the relationship SW/OD&#x2264;0.3. A first region A is defined between a pair of first boundary lines (L, L), second regions B are defined between a first boundary line (L) and a second boundary line (L), and third regions C are defined on the bead toe side of the second boundary lines (L). Defining SA, SB, and SC as the cross-sectional area (mm) of the first region A to the third region C, and defining the peripheral lengths (mm) of the first region A to third region C along the tire inner surface as a, b, and c, respectively, the relationship 7.5&#x2264;SA/a&#x2264;11.5 is satisfied.

A pneumatic tire has a ratio SW/OD between the total tire width SW and the tire external diameter OD satisfying SW/OD&#x2264;0.3. A first region A is defined between a pair of first boundary lines, second regions B are defined between a first boundary line and a second boundary line, and third regions C are defined on the bead toe side of the second boundary lines. Defining SA, SB, and SC as the cross-sectional area (mm) of the first region A to the third region C, and defining the peripheral length (mm) of the first region A to third region C along the tire inner surface as a, b, and c, SA/a and SB/b satisfy 7.5&#x2264;SA/a&#x2264;11.5 and 2.0&#x2264;SB/b&#x2264;6.0, and the ratio TDW/SW between the developed tread width TDW and the total tire width SW satisfies 0.7&#x2264;TDW/SW&#x2264;0.95.

The present technology provides a pneumatic tire that combines rolling resistance and wet grip performance while suppressing the occurrence of uneven wear. The pneumatic tire of the present technology has a cap rubber divided into a center portion that straddles a tire equator line and shoulder portions positioned on both sides thereof, a compound emphasizing wet grip performance and having a tan &#x3b4; at 0&#xb0; C. higher than that of the shoulder portions is disposed in the center portion and a compound emphasizing rolling resistance and having a tan &#x3b4; at 60&#xb0; C. lower than that of the center portion is disposed in both shoulder portions, and circumferential narrow grooves are formed on the respective shoulder sides of outermost main grooves in both the shoulder portions.

A pneumatic tire has two carcass layers including carcass cords are laid between a pair of bead portions, bead cores and bead fillers are disposed in the bead portions, and at least two belt layers are disposed on the outer circumferential side of the carcass layers, the tire being characterized in that both ends of the inner carcass layer are folded back from the tire inner side to the tire outer side around the bead cores, and the ends of the folded back portions of the inner carcass layer are disposed between the innermost belt layer and the outer carcass layer, while both ends of the outer carcass layer are disposed so as to pass between a main portion of the inner carcass layer and the bead fillers, and both ends of the outer carcass layer terminate at the bead portions without being folded back around the bead cores.

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Hiratsuka, Japan

Masatoshi Shimizu