| 摘要 |
PURPOSE:To prevent a sipe forming blade from being broken or deformed by making the depth of sipes in a tread ground contact surface which face the edges of respective circular arc shaped segments shallower than the other sipes in a sipe group, and forming sipes in a prescribed form at prescribed positions. CONSTITUTION:Block lines 9-12 are formed from blocks 5-8 which are partitioned by peripheral direction grooves 1-3 extending in a tire peripheral direction in a zig-zag shape and a width direction groove 4. Besides, the depth of sipes 13-15 which are formed from a sipe forming blade which is protrudingly- formed inward in the radius direction in the inner peripheral surface of a circular arc shaped segment is formed into more than 8mm, and the depth of the sipes within a range A from a tread surface position X-X which faces the edges of respective circular arc shaped segments in the tire peripheral direction is formed into less than 7mm. Moreover, the maximum depth (hs) and tire width direction length W of a sipe where only one end opens to the groove part is set(hs)XW<=70. Therefore, it is possible to form sipes in a desired form and at the necessary positions of a tread part, and prevent a sipe forming blade and so forth from being broken. |
