| 摘要 |
<p>PURPOSE:To improve durability in a bead part reinforced structure, by arranging carcass ply, first and second metallic cord reinforced layers around a bead core with their specified relationships, in case of a heavy-duty radial tire using a metallic cord carcass ply. CONSTITUTION:Carcass-ply turnup end height h1 is set to 0.3-0.5 times to height h6 from a bead base at the maximum width of a tire in time of prescribed air pressure charging, and height h2 in a tire axial outer end 4a of a first reinforced layer 4 is set to 0.7-0.9 h1, while height h4 in an inner side end 4b of the first reinforced layer 4 is set to being smaller than the h2. And, a lower end parts 6b is held between a first reinforced layr rolled-in part 4' and a carcass ply 2, and a second reinforced layer 6 is arranged within the range of a height h3 of 0.7- 1.3 h1 from height h5 at the inner side of a bead core at an arrangement angle of 10-50 deg. with a carcass cord in height h4. With this constitution, durability in a bead part reinforced structure is improvable.</p> |
