| 摘要 |
PURPOSE:To restrain resonance in an air columnar 20 between a circumferential groove 13 and a road surface to reduce noise, while performing water draining operation with the circumferential groove 13 formed on a tread part 12. CONSTITUTION:When noise is input to an air columnar 20, generation of standing wave of a definite frequency is obstructed by resistance due to the side wall 25 of a land part 16 continuously rising and falling in both the radial direction and the circumferential direction, further, the noise is curtailed by mutual interference due to reflection on the side wall 25, and hence the sound pressure level of the noise is reduced. |
