| 摘要 |
PURPOSE:To reduce the noise of the running sound of tire, for which a longitudinal line block group that is divided by a plurality of circumferential grooves as well as lateral grooves is provided on the tread, by setting the width of the lateral groove that belongs to a long pitch, narrower than the width of the lateral groove that belongs to a short pitch. CONSTITUTION:Four lines of longitudinal line block groups 5-8, i.e., each two lines on both sides of a center circumferential groove 1, are divided by a circumferential groove 2 that forms the same pattern in both sides of the center circumferential groove 1 extended along a center circumferential line O of a tread and in the center circumferential line O, and by a lateral groove 4, which crosses the circumferential grooves 1, 2, and which runs between each circumferential groove 1 and 2 or between the circumferential groove 2 and a tread groove T. With regard to this pneumatic tire, the circumferential length of each block including an adjacent lateral groove 4 is changed according to a plurality of length pitches. The width of the lateral groove that belongs to a long pitch is set narrower than the width of a lateral groove that belongs to the pitch that is shorter than this pitch. For example, the width of a lateral groove 4b that belongs to a pitch P2 is set narrower than the width of the lateral groove 4a that belongs to a pitch P1. |
