STEEL CORD OF A PNEUMATIC RADIAL TIRE FOR PREVENTING STRESS CONCENTRATION ON A CORE FILAMENT BY ADDING STRUCTURAL ELONGATION GENERATED BY STRAIN

摘要

PURPOSE: A steel cord of a pneumatic radial tire is provided to keep technical advantage of the existing core-parallel 2+5 structure and to improve the durability of the tire by removing stress concentration on a core filament by two-dimensionally deforming the core filament. CONSTITUTION: A steel cord applied for a belt or a carcass comprising a pneumatic radial tire has a 2+5 structure composed of two core filaments arranged in parallel to each other and five sheath filaments for covering the core filaments. Two core filaments are deformed two-dimensionally. The diameter of the core filament is 0.15¯0.30 mm. The diameter of the sheath filament is 0.22¯0.40 mm. The diameter ratio(Dc/Ds) of the core filament and the sheath filament is 0.5 <= Dc/Ds <= 0.85. The twist length(Ls) of the sheath filament is 10.0 <= Ls <= 20.0 mm.