Rigid core mold and method for manufacturing pneumatic tire using the same

Abstract

A technique for easily taking out a main body of a core mold is proposed. An annular core-mold main portionhaving a molding surfacefor shaping an inner surface of a pneumatic tire is included, and the core-mold main portionis composed of a plurality of segments each of which is taken out toward the inside in a radial direction. In the molding surfaceof the core-mold main portion, a ratio Bd/W of a maximum width W lying in regions for shaping sidewall portions and a width Bd in the tire axial direction measured at toe-end shaping positionsfor shaping toe ends of bead portions is not less than 0.80. In an inside zonefrom the toe-end shaping positionof the molding surfaceto the position of the maximum width W, the angle α of a tangent T drawn to the molding surfaceis not more than 15 degrees. The inside zoneincludes an oblique partin which the angle α of the tangent T is 30 to 45 degrees, and a ratio h/H of a length h in a radial direction of the oblique partand a length H from the toe-end shaping positionto an intersecting point P of a line drawn in the tire radial direction from the toe-end shaping positionoutwardly in the radial direction with the molding surfaceis less than 0.25.