| 摘要 |
PURPOSE: To provide a pneumatic tire which makes it possible to improve heel-and-toe wear resistance at the time of a tire being driven and, at the same time, to maintain traveling performance on an ice-and-snow road. CONSTITUTION: A pneumatic tire has a tread surface which is divided, by longitudinal grooves 2 and transverse grooves 3, into blocks 9 having a plurality of substantially rectangular block surfaces 5, and is equipped with at least two sipings 10 extending at an angle ranging from 88 to 90 degrees from the circumferencial direction of the tire, and in a circumference cross-section plane parallel to the equatorial plane of the tire, each of the sipings 10 is tilted, within a range up to its groove-bottom 11, at a siping angleβranging from 2 to 10 degrees relative to a tire-radius line R and also the groove-bottom 11 is tilted toward the earlier-contacting side of the block 9. An earlier-contacting wall surface 6 which contacts a road surface earlier when the tire rotates has a groove-bottom side 13A positioned on the earlier-contacting side while a later-contacting wall surface 6 which contacts the road surface later has a groove-bottom side positioned on the later-contacting side and, meanwhile, an angleγ2 formed by the earlier-contacting wall surface 6 with tire-radius line R in the circumference cross-section plane is not smaller than the siping angle and not greater than 30 degrees. |
