Air-inflated tyre

Abstract

A pneumatic tire for improving ABS braking performance on worn wet road surfaces. This pneumatic tire, while having a tread pattern specifying the direction of rotation, has a block divided by a main groove extending in the tire circumferential direction and a lateral groove extending in the width direction on the tread, and a pair of opposing apex angles of the block are Acute angle, in a pneumatic tire provided with at least one sipe on the block, while the length of the sipe gradually becomes longer from the tread surface to the bottom of the sipe, when a straight line parallel to the tire circumferential direction is When the block is equally divided into an area U with an acute angle on the kick-out side and an area L with an acute angle on the step-in side, the edge length L of the block measured along the main groove in the areas U and L respectively U , L L , and the distance from the top corner of the kick-out side of the block to the open end of the bottom of the sipe measured in regions U and L respectively 1 U ,1 L Set to 0.4≤1 L / L L ≤0.8, 0.2≤1 U / L U ≤0.6,1 L / L L ≥1 U / L U Relationship.

Description

technical field [0001] The present invention relates to a pneumatic tire suitable for a vehicle having an ABS (Antilock Braking System), and more particularly, to a pneumatic tire which improves the braking performance of the ABS on a wet road surface after wear. Background technique [0002] As is well known, in pneumatic tires, sipes (sips) are provided on the blocks (blocks) divided by the tread (Tread), so that the edge effect (the effect of cutting the thin water film on the road surface) can be increased, and the ABS braking performance on wet roads. In such a pneumatic tire, when the wear of the tread progresses, the edge effect of the sipe is substantially constant, but there is a problem that the rigidity of the block increases due to aging of the rubber or the height of the block becomes low, etc. , thereby reducing the ABS braking performance on wet roads. [0003] As a technique related to the sipe, the exposed length of the sipe is increased as wear progresses...

AI Technical Summary

Problems solved by technology

In such a pneumatic tire, when the wear of the tread progresses, the edge effect of the sipe is substantially constant, but there is a problem that the rigidity of the block increases due to aging of the rubber or the height of the block becomes low, etc. , thereby reducing ABS braking performance on wet roads

However, in a pneumatic tire having a tread pattern in a specified direction of rotation, since the opposing pair of apex angles are generally acute angles within the block, if the shape of the sipe is changed arbitrarily, the rigidity of the block may locally decrease, which cannot be achieved. Obtain a good ABS braking effect, and the problem that the block is twisted (crushed) occurs, etc.

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