| 摘要 |
PURPOSE:To enhance the traveling performance on a frozen wet ground surface by providing narrow-width land parts subdivided by narrow grooves to the land-part division inside a tread surface, and also by forming both deformation regions having a specific shape and shear deformation regions respectively. CONSTITUTION:On a tread surface 1, a large number of land-part divisions 4 are partitioned both by a plurality of main grooves 2 and by a plurality of auxiliary grooves 3 traversing the former. In the land-part division 4, a narrow-width land part 6 which has a groove depth h equal to or less than the groove depth H of interdivision grooves 2, 3 and which is subdivided by at least one narrow groove 5 is provided. And a bending deformation region in which the thickness TS of the narrow-width land part 6 measured in the direction perpendicular to the groove walls of the narrow grooves 5 is in the range of 0.1 to 0.5 times the groove depth h of the narrow groove 5 is provided. Further, a shear deformation region in which the thickness TL between the narrow groove 5 and interdivision groove 2 or 3 is in the range of 0.78 to 2.07 times the groove depth h of the narrow groove 5 is provided. Thus, molten water discharging function for improving on-ice performance, and frictional force securing function between the tire and a frozen surface are alloted to respective regions. |
