| 摘要 |
The present invention relates to a heavy duty tire being capable of preventing positional shift of carcass cords in the blowout direction while restricting rupture of the carcass cords for improving bead durability. A ply turnup portions 6 b of a carcass 6 includes a sub-portion 11 that extends proximate of an upper surface SU of a bead core 5 in a tire radial direction upon inclining towards a ply main body portion 6 a and further includes an auxiliary cord layer 20 for pressing the sub-portion outside thereof in the radial direction. A bead portion 4 is further provided with a U-shaped bead reinforcing layer 15 . A periphery of the bead core 5 is coated by a reinforcing rubber layer 15 made of high elastic rubber having a complex elastic modulus E*a of 20 to 70 MPa, and a rubber thickness T 0 of a clearance portion G at which bead wires 5 w and carcass cords 20 are adjacent is defined to be not less than 0.7 mm while a cushion rubber layer 16 made of low elastic rubber layer 16 is interposed between the reinforcing rubber layer 15 and the carcass cords 20. |
