| 摘要 |
<p>PURPOSE:To improve the durability of the bead part by making the stiffener of a tire a hard and soft complex with the fixed hardness and further forming the folded part of a carcass by the fixed measure. CONSTITUTION:The stiffener 5 of a tire is constructed of a hard stiffener 5a forming the base part and a soft stiffener 5b forming the decreased width part. The hard stiffener 5a is made such as to occupy 20-30% of the stiffener 5. The contact length (m) between the hard stiffener and a folded part and the contact length (n) between the hard stiffener and the carcass ply inside the tire in relation to the distance between the contact starting point of the carcass folded part with the hard stiffener and the carcass folded end are set within the range of m: (1/4-1/2).l, n: (/3-4/3).l. In this way, the deflection quantity of the folded part of the ply cord is integrally reduced, the durability of the bead part is heightened, and thereby the durability of the tire is largely improved.</p> |
