Pneumatic tire
AssigneeThe Yokohama Rubber Co., Ltd.
InventorHiroshi FUJII
Life of this patent
Estimating the term…
Abstract
In a state in which a pneumatic tire is mounted on a specified rim, inflated to 92% of a specified internal pressure, and loaded with a load of 75% of the maximum load capacity, an average thickness of an undertread rubber is smaller in a center region than in a shoulder region, a ratio (CAO/UAO) is 0.15 or more and 0.95 or less, a ratio (UAI/UAO) is less than 1, and a ratio (L/W) is 0.29 or more and 0.51 or less, in a tire meridian cross-sectional view, where CAO, UAO and UAI are cross-sectional areas of the cap tread rubber, the undertread rubber, and the undertread rubber in the center region, respectively, L is a tire width direction dimension from a defined intersection point to a ground contact edge, and W is a tire width direction dimension of each shoulder region.
Claims11
1-6. (canceled)
A pneumatic tire, comprising:
- a carcass comprising at least one carcass ply;
- a belt comprising a belt layer comprising cords, the belt being disposed on an outer side in a tire radial direction of the carcass;
- and
- a tread rubber disposed on the outer side in the tire radial direction of the belt, the tread rubber constituting a portion of a tread portion;
- at least one circumferential main groove having a total width of 15% or greater of a ground contact width being formed in the tread portion,
- the tread rubber comprising an undertread rubber and a cap tread rubber formed on the outer side in the tire radial direction of the undertread rubber, the cap tread rubber being formed of rubber having a hardness lower than a hardness of the undertread rubber,
- in a state in which the pneumatic tire is mounted on a specified rim, inflated to 92% of a specified internal pressure, and loaded with a load of 75% of a maximum load capacity,
- when a tire ground contact width is divided into four regions in a tire width direction in a tire meridian cross-sectional view and two out of the four regions located in a center in the tire width direction are regarded as a center region and remaining two regions are regarded as shoulder regions, an average thickness of the undertread rubber being smaller in the center region than in the shoulder region,
- in the tire meridian cross-sectional view, in a region of the shoulder region, located closer to an inner side in the tire radial direction than an imaginary line that extends in parallel to a tire profile line at a position located 1.6 mm on the outer side in the tire radial direction from a groove bottom of the circumferential main groove, a ratio CAO/UAO of a cross-sectional area CAO of the cap tread rubber to a cross-sectional area UAO of the undertread rubber being 0.15 or more and 0.95 or less,
- in the tire meridian cross-sectional view, a ratio UAI/UAO of a cross-sectional area UAI of the undertread rubber in the center region to a cross-sectional area UAO of the undertread rubber in the shoulder region being less than 1, and
- in a tire plan view, a ratio L/W of a tire width direction dimension L from an intersection point P1 between an extension line of the imaginary line and a tread profile line to a ground contact edge to a tire width direction dimension W of each shoulder region being 0.29 or more and 0.51 or less.
Dependencies are inferred from the claim text.