| 摘要 |
PROBLEM TO BE SOLVED: To attain a traveling of 20,000 km or more without failure of a carcass ply by setting the cord space between an outermost ply and the inside ply adjacent to this ply so as to exceed the cord spaces between the adjacent plies of the remaining plies except the outermost ply. SOLUTION: A carcass 3 in the area of a crown part 2 satisfies the relation ofδ<δ1,δ>δ2 among a cord spaceδ(mm) between a cord 3-1c of an outermost play 3-1 and a cord 3-2c of a second ply 3-2, a cord spaceδ1 (mm) between the cord 3-2c of the second play 3-2 and a cord 3-3c of a third ply 3-3, and a cord spaceδ2 (mm) between the cord 3-3c of the third ply 3-2 and a cord 3-4c of a fourth ply 3-4. In this case,δ1=δ2 orδ1≈δ2 may be adapted. According to such a structure, though the shearing strain between the outermost play 3-1 and the second ply 3-2 is unchanged, the shearing stress can be significantly reduced. |
