This invention provides a pneumatic tire having its weight reduced without degrading the durability of bead portions. Provided is a pneumatic tire comprising, as a framework, at least one carcass ply comprising a steel cord covered with rubber. Letting d (mm) be the cord diameter of the steel cord and T (MPa) be the tensile strength of a steel filament forming the steel cord, the following relation is satisfied: a1T−b1>d>a2T+b2 (where a1 is 3.65×10−4 mra/MPa, b1 is 0.42 mm, a2 is −8.00×10−5 mm/MPa, and b2 is 0.78 mm), and the tensile strength T of the steel filament is 3000 MPa (exclusive) to 4000 MPa (exclusive) and the number of hits E under a bead core of the steel cord in the carcass ply is 12 hits/25 mm (exclusive) to 38 hits/25 mm (exclusive).
PNEUMATIC TYRE
2016-06-16
Patent
Electronic Resource
English
IPC: | B60C VEHICLE TYRES , Fahrzeugreifen |