Run-flat tire

Abstract

Provided is a run-flat tire that achieves a high dimension of both run-flat durability and riding comfort, and enables the improvement of steering stability during normal traveling. In the side-reinforced run-flat tire, the relationship between the rim width (Wr) and the distance (Do) to the tire equator plane from the center position of a peripheral-direction primary groove positioned to the outermost side in the widthwise direction of the tire in the outside region of the vehicle is 0.20 ≤ Do / Wr ≤ 0.30, the relationship between the rim width (Wr) and the distance (Di) to the tire equatorial plane from the center position of a peripheral-direction primary groove positioned to the outermost side in the widthwise direction of the tire in the inside region of the vehicle is 0.25 ≤ Di / Wr ≤ 0.35, the relationship between the groove width (Wi) of the peripheral-direction primary groove positioned at the outermost side in the widthwise direction of the tire at the inside region of the vehicle and the groove width (Wo) of the peripheral-direction primary groove positioned at the outermost side in the widthwise direction of the tire at the outside region of the vehicle is 0.80 ≤ Wo / Wi ≤ 0.90, the relationship between the thickness (Ga) at a rim check line position of an outside rubber portion at the outside of a carcass layer and the greatest thickness (Gb) of same is 0.8×Gb ≤ Ga ≤ 1.0×Gb, and the relationship between the thickness (Gc) at the rim check line position of an inside rubber portion at the inside of the carcass layer and the thickness (Ga) is 0.7×Ga ≤ Gc ≤1.0×Ga.

Description

technical field [0001] The present invention relates to a sidewall-reinforced zero-pressure tire, and more specifically, to a tire capable of multidimensionally combining durability during zero-pressure running and ride comfort during normal running, and improving ride quality during normal running. Stable zero pressure tires. Background technique [0002] Conventionally, as zero-pressure tires capable of running in a blown state, sidewall-reinforced zero-pressure tires in which a sidewall reinforcing layer having a crescent-shaped cross section is arranged inside the sidewall portion have been proposed (for example, refer to Patent Documents 1 to 5). . [0003] According to such a sidewall-reinforced zero-pressure tire, in order to improve the durability during zero-pressure running, the thickness of the sidewall reinforcement layer is generally increased or a high-hardness rubber composition is used for the sidewall reinforcement layer. [0004] However, when the thickne...

AI Technical Summary

Problems solved by technology

In addition, when the spring constant of the tire is reduced in order to ensure ride comfort, there is also a problem that the driving stability during normal driving will deteriorate.

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