| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a pneumatic radial tire having high rigidity at a bead part. SOLUTION: In a cylindrical ply molding step, cylindrical plies 4 are molded so that one or more plies 3 for a carcass having cords 2θ(θ≠0) aligned are inclined at an angle to an axial line of the cylinder. In a cylindrical ply holding step, bead cores 5A, 5B are externally inserted from both sides of the ply 4 into positions isolated from its inside, and the plies 4 are urged to inner surfaces of the cores 5A, 5B to hold the plies. In an extending step, a body region 3i of an inside part between the cores 5A and 5B of the ply 4 is axially extended while being twisted to satisfy a formula: La/cosθ=Lb/cosβ(where La indicates an axial length of the body region before the extending step, Lb indicates an axial length of the region after the extending step, andβindicates an angle after the cord after the extending step is formed to the axial line). In a folding step, an outside region 3o of an outside part of the cores 5A, 5B is folded to the region 3i side.
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