| 摘要 |
PROBLEM TO BE SOLVED: To improve brake performance and traction performance on an ice road surface, while improving wear resisting performance on a dry road surface. SOLUTION: Middle land part 51 structuring a middle land part lines 50 formed on a tread 12 are divided into three areas of a treading area 51A in a circumferential direction, a circumferential center area 51C, and a kicking-out area 51C, by a pair of dividing auxiliary grooves 54, 55 extending in a tire width direction. In the treading area 51A and the kicking-out area 51B, a plurality of small holes opening on a tread surface and extending inward in a tire diametrical direction. In the circumferential center area 51C, a plurality of sipes 53 extending in a tire width direction are formed. Divided auxiliary grooves 54, 55 are formed to have groove width wider than the sipep 53. Therefore, the block rigidity of the treading area 51A provided with the small holes 52 and the kicking-out area 51B can be improved, and the falling amount of the circumferential center area 51C equipped with the sipes 53 can be reduced. COPYRIGHT: (C)2006,JPO&NCIPI |
