| 摘要 |
<p>It is an object of the present invention to reduce fretting between strands in a steel cord, to suppress reduction in cord strength caused by running, to enhance rubber penetrability, and to improve tire durability. The steel cord includes a cord main portion 19 of a triple layer-stranding structure including: a core 16 formed from one core strand f1, an inner sheath 17 including N (2 to 5) inner sheath strands f2 stranded with a stranding pitch Pi around the core; and outer sheath 18 formed from M (6 to 11) outer sheath strands f3 stranded with a stranding pitch Po around the inner sheath. Diameters of the strands f1, f2 and f3 are equal to each other, and stranding directions of the sheaths 17 and 18 are the same. A difference (|Ai-Ao|) between a stranding angle Ai of the inner sheath strand f2 and a stranding angle Ao of the outer sheath strand f3 is greater than 1° and smaller than 3°.</p> |
