| 摘要 |
In a heavy-load radial tyre, metal cords have a single twist structure obtd. by twisting 3 to 5 metal filaments having a filament dia. of 0.13 to 0.32 mm, and having an arithmetic-mean of elongations P1. 0.35 to 1.0%, in the range of a load of 0.25 to 5 kgf/piece cords are disposed as a carcass ply such that the cord gap at the end portion of the carcass ply is at least 0.25 mm. This arrangement makes it possible to reduce drastically the tie wt., to avoid problems with workability for loose bead etc., to improve breakage resistance at the end portion of the carcass ply, corrosion and fatigue resistance and anti-fretting property. Simultaneously it is possible to improve drastically side scratch resistance of the radial tyre (anti-cord break property). The radial tyre may be designed to satisfy a specific relationship between the tensile strength TS of the metal filament and the filament dia. d in the range where load index in accordance with ISO 4209/1 is 121 or below and 122 or above. |
