pneumatic tire

Abstract

The present invention provides a tire which is provided with central side main grooves (1,1) and tire shoulder side main grooves (2,2) at a tire surface part T. Central strip-shaped patterns (10) are curved between the main grooves (1,1), and central strip-shaped patterns (20) are curved between the main grooves (1,2), wherein, on the central strip-shaped patterns (10) and the central strip-shaped patterns (20), a plurality of tread grooves (11,21) which are terminated in the strip-shaped patterns are formed according to a mode that the groove width reduces gradually in a process of approaching the central side. The distance between the central position of the tire surface part (T) and the center of the main groove (1) is set to 15%-25% of the distance between the central position and a grounding end. The distance between the central position of the tire surface part (T) and the main groove (2) is set to 60%-80% of the distance between the central position and the grounding end. The width of the main groove (1) is set to 70%-90% of the width of the main groove (2). The total area of the main groove (1) and the main groove (2) is set to 15%-25% of the area of the grounding area (A) in the tire surface part (T). The groove area ratio of a central area (Ac) is set to be smaller than that of a tire shoulder area (As).

Description

technical field [0001] The present invention relates to a pneumatic tire provided with four main grooves extending in the tire circumferential direction on the tread portion, and more specifically, to a pneumatic tire capable of reducing passing noise while maintaining good rolling resistance and wet performance . Background technique [0002] When a vehicle passes by, the pneumatic tires installed on the vehicle will generate noise, which is generally called passing sound. The passing sound is amplified by the suction effect when the air in the grooves of the tread portion is compressed and released. Therefore, reducing the groove area of ​​the tread portion is effective for reducing the passing sound. For example, in a pneumatic tire in which four main grooves extending in the tire circumferential direction are provided on the tread portion (for example, refer to Patent Document 1), the passage sound can be reduced by reducing the groove area of ​​the tread portion. [...

AI Technical Summary

Problems solved by technology

[0003] However, when the groove area is reduced to reduce the passing sound, there is a problem that the drainage performance is reduced and the wet performance is deteriorated.

In addition, when the groove area is reduced, the amount of rubber in the tread portion increases, so there is also a problem that the rolling resistance deteriorates

Therefore, it is difficult to reduce pass-through sound while maintaining good rolling resistance and wet performance, and it is currently difficult to satisfy these characteristics at the same time

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