| 摘要 |
PURPOSE: To control partial wear of a shoulder part of a tire and to enhance the hill climbing performance on an ice and snow road in unloaded vehicle condition by determining the depth of a specified number % of sipes out of the total number of sipes, which are prepared in a block within a range extending from the outermost main groove to the inside/outside in the tire width direction, as prescribed percentage of the depth of the main groove. CONSTITUTION: A tread surface is provided with a plurality of main grooves 10, which extend in the circumferential direction EE' of a tire and which have groove width of 5 to 20mm, and a plurality of sub-grooves 11, which extend in the direction of the width of the tire, thereby partitioning blocks 12. At least one sipe 14 extending in the direction of the width of the tire are arranged in the respective blocks 12. Both ends of the sipes 14 open at the side edge of the block 12. The depth of at least 70, 80% in number of the sipes 14, which exist in the range extending from the outermost main groove 10 to the inner/ outer domains in the direction of the width of the tire, i.e., the block 12 of ranges A, B in the center domain and ranges C, D in the shoulder domain, should be 65 to 80%, 35 to 50% of the depth of the outermost main groove 10. |
