HEAVY-DUTY PNEUMATIC TIRE

摘要

A heavy-duty pneumatic tire includes a carcass ply including a main portion extending between bead cores and a pair of turn-up portions, a first reinforcing layer of a steel cord disposed in each bead portion in a U-shaped manner, and a second reinforcing layer of an organic fiber cord disposed in each bead portion and at least a part of the second reinforcing layer extending in a radial direction of the tire at an axially outward location of the first reinforcing layer. The second reinforcing layer includes an axially inner second ply and an outer second ply. The outer second ply has an inner end positioned below the bead core. The inner second ply has an inner end located axially inward of the inner end of the outer second ply, and has a substantially same length as the outer second ply in a tire cross-section.

主权项

1. A heavy-duty pneumatic tire comprising:
a tread portion; a pair of sidewall portions; a pair of bead portions each having a bead core therein; a carcass comprising a carcass ply comprising a main portion extending between the bead cores and a pair of turn-up portions each wound up around the bead core from axially inside to the outside of the tire; a first reinforcing layer of a steel cord disposed in each bead portion, the first reinforcing layer extending in a U-shaped manner to surround the bead core; a second reinforcing layer of an organic fiber cord disposed in each bead portion, at least a part of the second reinforcing layer extending in a radial direction of the tire at an axially outward location of the first reinforcing layer; the second reinforcing layer comprising an inner second ply being in contact with the first reinforcing layer and an outer second ply being in contact with the inner second ply; the outer second ply having an inner end positioned below the bead core; and the inner second ply having an inner end located axially inward of the inner end of the outer second ply, the inner second ply having a substantially same length as the outer second ply in a tire cross-section.