Pneumatic tire with tread having groove area ratio
AssigneeThe Yokohama Rubber Co., Ltd.
InventorKouichi Koutoku
Life of this patent
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Abstract
In a pneumatic tire, a difference Gs−Ge falls in a range of Gs−Ge≧0.10, where Gs is a groove area ratio for a wear rate 0% and Ge is a groove area ratio for a wear rate 100%. Further, a groove area ratio G for a wear rate 20% falls in a range of (Gs−G)/(Gs−Ge)≧0.30, and a groove area ratio G for a wear rate 35% falls in a range of (Gs−G)/(Gs−Ge)≧0.50.
Claims17
A pneumatic tire, having a tread that includes at least three circumferential main grooves extending in a tire circumferential direction, a plurality of widthwise grooves extending in a tire width direction, and a plurality of block arrays segmented by the circumferential main grooves and the widthwise grooves, said tread further including a pair of shoulder ribs disposed outwardly of the plurality of blocks in a widthwise direction of the tire, and which are not intersected by the widthwise grooves,
- provided that a ratio of a sum A+B of a total groove area A of the circumferential main grooves and a total groove area B of the widthwise grooves on a tire-ground contact surface to a tire-ground contact area X is defined as a groove area ratio G=(A+B)/X, and that a wear rate of the tread is defined based on a condition where a remaining groove depth of the circumferential main grooves is 1.6 millimeters as a reference (100%),
- a difference Gs−Ge falls in a range of Gs−Ge≧0.10, where Gs is a groove area ratio for a wear rate 0% and Ge is a groove area ratio for a wear rate 100%, the groove area ratio G for a wear rate 20% is in a range of (Gs−G)/(Gs−Ge)≧0.30, and the groove area ratio G for a wear rate 35% is in a range of (Gs−G)/(Gs−Ge)≧0.50.
A pneumatic tire having a tread that includes at least three circumferential main grooves extending in a tire circumferential direction, a plurality of widthwise grooves extending in a tire width direction, and a plurality of block arrays segmented by the circumferential main grooves and the widthwise grooves,
- provided that a ratio of a sum A+B of a total groove area A of the circumferential main grooves and a total groove area B of the widthwise grooves on a tire-ground contact surface to a tire-ground contact area X is defined as a groove area ratio G=(A+B)/X, and that a wear rate of the tread is defined based on a condition where a remaining groove depth of the circumferential main grooves is 1.6 millimeters as a reference (100%),
- a difference Gs−Ge falls in a range of Gs−Ge≧0.10, where Gs is a groove area ratio for a wear rate 0% and Ge is a groove area ratio for a wear rate 100%, the groove area ratio G for a wear rate 20% is in a range of (Gs−G)/(Gs−Ge)≧0.30, and the groove area ratio G for a wear rate 35% is in a range of (Gs−G)/(Gs−Ge)≧0.50,
- wherein the groove area ratio G of the tread for each wear rate is adjusted by providing bottom-up sections on bottoms of the widthwise grooves, the bottom-up sections provided at positions corresponding to laterally intermediate portions of individual blocks of the block arrays adjacent to the widthwise grooves.
Dependencies are inferred from the claim text.