| 摘要 |
PURPOSE:To reduce tire noises due to air column resonance without damaging dry grip performance and wet grip performance by specifying a sea/land ratio in a specified rang of the groove width of a longitudinal groove. CONSTITUTION:A longitudinal groove 7 has the groove width W measured axially of a tire within 2570mm of range to reduce air column noises. Further, a sea/land ratio is set within 25-45% of range. Here a sea/land ratio is defined as a ratio of a land area to groove area in all apparent ground contacting region contacting a flat road surface under the reference condition that the tire is rimmed with a regular rim and added with regular internal pressure and load. Also all the apparent ground contacting region is all outer peripheral areas in the outer edge line (a) surrounding the outer edge of the ground contacting range in a ground contacting pattern. Also, a land area is the total area of hatched portions L1 actually contacting the road surface in all apparent ground contacting regions and the sea area is the total area of non-ground contacting portions S1 in the groove. |
