| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire excellent in both steering stability and vibration ride comfort. Ž<P>SOLUTION: The pneumatic radial tire is provided with a carcass 2 and a crossing belt layer 3 using a steel cord as a reinforcement material. A bead core 1 buried in a bead part 11 is a cable bead in which a plurality of wires are wound on a periphery of the core becoming a central structure and a plurality of layers of sheathes are arranged, and rigidity of the steel cord per unit width of the crossing belt layer 3 satisfies a relationship represented by a formula: (A-800)/B≥20, wherein A is cord traction rigidity (kg) defined by stress at 1% traction × the number of hitting (number/50 mm), and B is cord bending rigidity (g/mm) defined by inclination at 2-6 mm pushing-in deformation of stress-bending displacement curve obtained by cord 3-point bending test × the number of hitting (number/50 mm). Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
