| 摘要 |
We provide a run flat tire capable of ensuring high resistance to coming off of a bead portion from a rim in run flat running, while maintaining high durability of a side-reinforcing rubber. Specifically, a run flat tire, has a tread portion, a pair of sidewall portions continuous with respective sides of the tread portion, bead portions continuous with the respective sidewall portions, bead cores each embedded in the corresponding bead portion, and a side-reinforcing rubber having a crescent-shaped cross section and provided in each sidewall portion, wherein in a cross section in the tire width direction thereof: diameter of an annular inner end in the tire radial direction of the bead core is larger by 3.0-4.5 mm than rim diameter of a prescribed rim; and diameter of a circle collectively formed by the bead heal point is smaller by 1.7-2.9 mm than the rim diameter of the prescribed rim. |
| 主权项 |
1. A run flat tire, having a tread portion, a pair of sidewall portions continuous with respective sides of the tread portion, bead portions continuous with the respective sidewall portions, bead cores each embedded in the corresponding bead portion, and a side-reinforcing rubber having a crescent-shaped cross section and provided in each sidewall portion, wherein in a cross section in the tire width direction thereof:
diameter of an annular inner end in the tire radial direction of the bead core is larger by 3.0-4.5 mm than rim diameter of a prescribed rim; and provided that an intersection of a straight line tangent to an outer contour line of a bead heal of the bead portion at an end on the bead base surface side of the outer contour line and a straight line tangent to the outer contour line of the bead heal at an end on the bead back surface side of the outer contour line represents “bead heal point” in a case where the outer contour line of the bead heal of the bead portion is constituted of a curved line, and provided that an intersection of an outer contour line, on the bead base surface side, of the bead heal and an outer contour line, on the bead back surface side, of the bead heal represents “bead heal point” in a case where the outer contour line of the bead heal of the bead portion is constituted of straight lines, diameter of a circle collectively formed by the bead heal point is smaller by 1.7-2.9 mm than the rim diameter of the prescribed rim. |
