| 摘要 |
A heavy duty pneumatic radial tire comprising a carcass (4) of one or more rubberized cord plies extending between a pair of bead cores (3) each embedded in a bead portion (1) and containing cords arranged along a plane inclusive of a rotating axial center of the tire, at least one of which plies being wound around the bead core from the inside of the tire toward the outside thereof to form a turnup portion (4t), and a bead portion reinforcing layer (5) comprised of a single rubberized steel cord layer covering a surface of the carcass ply over a region ranging from an outer position (4te) of the turnup portion (4t) in a radial direction of the tire along an outer surface of the turnup portion through the bead core (3) up to an inside of the tire, in which an inclination angle of steel cord in the bead portion reinforcing layer (5) with respect to a circumferential line of the tire is within a range of 22-35 DEG in outermost end portions outside and inside the tire in the radial direction, and an inclination angle of steel cord outside and inside of the tire in the vicinity of a straight line (L) passing through a graphic center of gravity (Cg) in the bead core (3) at a section thereof and in parallel to the rotating axis of the tire is within a range of 5-50 DEG added to the inclination angle range of the above outermost end portion. <IMAGE> |
