Pneumatic tire and manufacturing method therefor

A method for manufacturing a pneumatic tire comprising a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, and a carcass extending between the bead cores, wherein

• at least one of the bead cores comprises a wire wound body in which one bead wire is spirally wound in a continuous manner around a tire rotational axis so that a plurality of layers of the bead wire are formed in a radial direction of the tire, and
• the wire wound body comprises a first part and a second part, the first part comprising a plurality of layers of the bead wire each extending in a circumferential direction of the tire having a constant radius from the tire rotational axis, and the second part comprising a plurality of layers of the bead wire each extending in the circumferential direction of the tire while changing its radius from the tire rotational axis,
• the method comprising
• a wire wound body forming step in which one bead wire is spirally wound in a continuous manner on a predetermined area of a side surface of an inner core to form the wire wound body, wherein the wire wound body forming step comprises
• a wire fixing step in which a winding-starting end of the bead wire is pushed and fixed on the predetermined area, and then
• a wire winding step in which the bead wire is spirally wound on the predetermined area by rotating the inner core around the tire rotational axis,
• wherein the wire winding step comprises
• a first rotating step in which the inner core rotates to wind the bead wire while maintaining a constant angle α1 between the tire rotational axis and a Y-axis direction that is a feeding direction of the bead wire to the inner core, and
• a second rotating step in which the inner core rotates to wind the bead wire while gradually increasing the angle α1 wherein the angle α1 is increased by turning the inner core around a radial axis passing through a point “O” at which a core equatorial plane and the tire rotational axis intersect.