| 摘要 |
PURPOSE: To prevent a reduction in strength of a ply cord and a reduction in tire life by setting the angle formed by the end surface and circumferential side surface of a bead wire to an obtuse angle having a specified range on the rear side of the section, and situating the top end side of the splice section on the inside of a bead. CONSTITUTION: A circular sectional wire 12 covered with rubber is spirally turned, and the wire 12 is bundled, whereby a bead core 10 is formed. The winding start and terminal ends of the wire 12 of the bead core 10 have a splice-cut form, and the angleψin the rear intersection B between the side surface of the wire 12 and a splice-cut section 15 is within a range of 130 deg.<=ψ<=170 deg.. The bead core 10 is formed in such a manner that the wire top end part intersection A between the side surface of the wire 12 and the splice-cut section 15 is situated on the inside of the bead, and the rear intersection B on the outside of the bead. According to such a constitution, reduction in strength of a ply cord and reduction in tire life can be prevented.
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