| 摘要 |
PURPOSE:To restrain group cracks from occurring in groove bottom parts by press- fitting solid substance in a part of each lateral groove inside a tire whose one end is open to a tire side part, so as to relieve tensile strain applied to the bottom of the lateral groove by means of compressive strain applied in advance at the time of driving and so forth. CONSTITUTION:In a tire, a number of deep lateral grooves 3 are provided in the shoulder area 1a of a tread 1, five longitudinal groove 4 which extend in zig-zag form are provided in the central part of the tread 1, and sub-grooves 5 which continue between longitudinal grooves 4 in a straight or zig-zag form are provided, thus a tread pattern in a block pattern which has polygonal blocks 6 and pentagonal blocks 7 may be formed. Besides, lateral holes 8 in small diameter cylindrical shape are drilled in parallel to the groove bottoms of the lateral grooves 3 on both ends, on the groove bottom side of the lateral grooves 3 which are adjacent to the base end part of the blocks 7 in the respective shoulder areas. In this case, solid substances 9 each of which has a cross-sectional area in the range of 2-18 times as wide as cross- sectional area of the opening part of each lateral hole 8 and formed in bar-typed chip body or the like a little shorter than the depth of the lateral holes 8 by means of rubber material on the lateral hole 8 part are respectively press-inserted and filled into the respective lateral holes 8. |
