| 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 filament length equivalent to one twist pitch, on each of filaments which constitute an outer layer sheath, with the filament length equivalent to one twist pitch being a cycle; twisting these filaments 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 filaments 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 in a manner in which 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 by mounting such pneumatic radial tires on a vehicle, to improve fuel efficiency. <IMAGE></p> |
