Pneumatic tire

Abstract

Provided is a pneumatic tire with a durability improved by preventing the oxidation degradation of a belt layer. The pneumatic tire includes: an air permeation preventive layer disposed in the inner surface of the tire; a belt layer buried in a tread part; and a cord layer formed by arranging a plurality of cords. The cord layer is disposed between the air permeation preventive layer and the beltlayer, and extends to a bead part side further from a tire maximum width position. In addition, at least a part of the cord layer is located close to the outer surface of the tire, at a position closer to the bead part side than the tire maximum width position, so that the distance between the cords and the outer surface of the tire is not more than 2 mm. The following configuration may alternatively be possible. A cord layer is formed by arranging cords in parallel. The inner part of the cord layer is disposed between a carcass layer and the belt layer, while the outer part of the cord layeris disposed on the outer circumferential side of the belt layer, along the belt layer. Moreover, the cords of the cord layer are continuously extended, in a straddling manner, between the inner and outer parts.

Description

technical field [0001] The present invention relates to a pneumatic tire in which a belt layer is embedded in a tread portion, and more specifically, to a pneumatic tire in which durability can be improved by preventing oxidative degradation of the belt layer. Background technique [0002] In a pneumatic tire in which a belt layer is embedded in the tread portion, peeling of the cords and the covering rubber at both end portions of the belt layer in the tire axial direction can be cited as a cause of deterioration in durability. In particular, when the belt layer deteriorates, peeling of the cords and the covering rubber tends to occur. It has been studied that such deterioration of the belt is promoted because the oxygen in the air oxidizes the covering rubber of the belt during the process in which the air inside the tire leaks toward the outside of the tire. [0003] Therefore, it has been proposed that a cord auxiliary layer composed of a plurality of cords arranged in ...

AI Technical Summary

Problems solved by technology

Then, the moisture promotes the deterioration of the belt cord, which becomes the main cause of reducing the durability of the pneumatic tire.

In addition, since the amount of deformation of the supporting portion during tire running is relatively large, when the end portion of the cord auxiliary layer is brought close to the outer surface of the tire in the vicinity of the supporting portion, it is easy to cause damage starting from the approaching portion. Main causes of durability reduction of pneumatic tires

That is, even if the oxidative deterioration of the belt layer is prevented by the cord auxiliary layer, the effect of improving the durability of the pneumatic tire cannot be sufficiently obtained.

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