Pneumatic tire

Abstract

The invention provides a pneumatic tire which can uniformly improve the noise performance, snow rode performance, and ice rode performance. The pneumatic tire is provided with a center pattern block (5) and a middle pattern block (6). The two pattern blocks are provided with a plurality of sipes (14). A central transverse groove (4A) is inclined at an angle in the range of 5-20 degrees, and the average groove width is 7-15% of the maximum length (L3) of the center pattern block. A middle transverse groove (4B) is inclined at an angle in the range of 5-25 degrees, and the average groove width is 7-11% of the maximum length (L4) of the middle pattern block (6). In the grounding surface under the standard load state, the tire circumferential distance (La) of a first intersection point (K1) and a second intersection point (K2) is 0.75-1.00 times of the difference (L5-L6) of the length of the grounding surface at the tire equator position (Ce) and the length of the grounding surface at the middle position (6c) of the middle pattern block, and the first intersection point is obtained by the intersection of the central transverse groove and a central main groove (3A), and the second intersection point is obtained by the intersection of the middle transverse groove and the central main groove.

Description

technical field [0001] The present invention relates to a pneumatic tire which improves noise performance, snow road performance and icy road performance in a balanced manner. Background technique [0002] Pneumatic tires for winter use not only on snowy and icy roads but also on asphalt roads, etc. Therefore, it is required to improve not only snow performance and icy performance but also noise performance in such winter pneumatic tires. [0003] For example, in order to improve performance on snowy roads, it has been proposed to increase the volume of lateral grooves in the tread portion for the purpose of increasing snow column shear force. However, in this method, since the ground contact area of ​​the tread portion is reduced, there is a problem that performance on icy roads is deteriorated. In addition, when the volume of the lateral groove is large, there is a problem that the air in the lateral groove flows out along with the rolling of the tire, thereby increasing...

AI Technical Summary

Problems solved by technology

However, in this method, since the ground contact area of ​​the tread portion is reduced, there is a problem that performance on icy roads deteriorates.

In addition, when the volume of the lateral groove is large, there is a problem that the air in the lateral groove flows out along with the rolling of the tire, and the pumping sound etc. generated thereby increases, so that the noise performance is also deteriorated.

Thus, there is a reciprocal relationship between snow performance, ice performance, and noise performance, making it difficult to improve all of the above performances in a balanced manner

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