| 摘要 |
<p>Steel cord used as a reinforcement for a belt layer in pneumatic tires. The steel cord is manufactured by forming a plurality of bends per strand length equivalent to one twist pitch on a strand, which constitutes an outer layer sheath, with the strand length equivalent to one twist pitch being a cycle, twisting these strands while the bends belonging to the same phase are aligned in a cord axial direction, and subjecting cord side surfaces to compression processing. As a result, flat side surface portions are formed, in which a plurality of strands forming the outer layer sheath are positioned substantially in the same plane. The steel cord thus formed is used in reinforcement plies for pneumatic radial tires such that the reinforcement plies are laminated so that the flat side surface portions are mutually parallel. Accordingly, the distribution of shearing stress acting on rubber between the flat side surface portions of the steel cord is made uniform and rigidity of a tire per amount of steel cord used is enhanced. Therefore, it is possible to reduce a weight of the steel cord used per tire and improve fuel efficiency by mounting such pneumatic radial tires on a vehicle.</p> |
