Pneumatic tire
AssigneeThe Yokohama Rubber Co., Ltd.
InventorRisa Tauchi
Life of this patent
Estimating the term…
Abstract
A pneumatic tire is mounted on a 5° rim. A bead core includes a bottom inclined 0°-5° in a direction in which the bottom diverges outward in the radial direction as the bottom extends from an inner side toward an outer side in the width direction. A bead includes a base, a toe, a heel, and a back surface. The heel connects to the back surface by an arc. The base includes a region between a core lower inner end position on an inner circumferential surface of the bead and being identical to a position of a bead core inner end and a core lower outer end position on an inner circumferential surface of the bead and being identical to a position of a bead core outer end in the width direction. The base has a curved line projecting toward the inner side in the radial direction in a cross-section.
Claims11
A pneumatic tire, comprising:
- a pair of bead portions disposed on both sides of a tire equatorial plane in a tire width direction;
- and
- a bead core provided on each of the pair of bead portions,
- the pneumatic tire being mounted on a 5°-taper specified rim,
- the bead core has a hexagon shape in a tire meridian cross-section and includes a bead core bottom corresponding to an inner circumferential surface of the bead core and inclined within a range of 0° or larger and 5° or smaller with respect to a tire rotation axis in a direction in which the bead core bottom diverges outward in a tire radial direction as the bead core extends from an inner side in a tire width direction toward an outer side in the tire width direction,
- the bead portion comprising a bead base portion formed on an inner circumferential surface of the bead portion, a toe portion located on an inner side of the bead base portion in the tire width direction, a heel portion located on an outer side of the bead base portion in the tire width direction, and a back surface portion located on an outer side of the heel portion in the tire radial direction and facing an outer side in the tire width direction,
- the heel portion being connected to the back surface portion through an arc portion formed like an arc in the tire meridian cross-section,
- the bead base portion comprising a region between a core lower inner end portion position located on an inner circumferential surface and being identical to a position in the tire width direction of a tire width direction inner end portion of the bead core and a core lower outer end portion position where the position located on an inner circumferential surface and being identical to a position in the tire width direction of a tire width direction outer end portion of the bead core, and
- the bead base portion having a curved line projecting toward an inner side in the tire radial direction in the tire meridian cross-section;
- wherein
- the curved line extends continuously from the core lower inner end portion position to the core lower outer end portion position in the bead base portion;
- and
- assuming that, for the bead base portion, DP is a diameter at a core bottom outer end portion position where the position in the tire width direction is identical to the position in the tire width direction of the tire width direction outer end portion of the bead core bottom, DQ is a diameter at the core lower outer end portion position, DPR is a diameter at a position on the specified rim corresponding to the core bottom outer end portion lower position, and DQR is a diameter at a position on the specified rim corresponding to the core lower outer end portion position, (DPR−DP)/DPR×100 is at least 0.2% larger than (DQR−DQ)/DQR×100.
Dependencies are inferred from the claim text.