To easily manufacture a two-piece wheel by plastically forming regular curls of a rectangular section on both ends of a metal cylindrical member, and directly forming a rim from the cylindrical member.
A drop center part is formed on a barrel part of the metal cylindrical member 2, the both ends 3 of the cylindrical member 2 are plastically expanded, the expanded ends 3 are regularly curled into the curls 4 having a rectangular cross section (method 1). Alternatively, the expanded ends 3 are curled into the curls 4 having a circular cross section, and the curls 4 are finished into a regular shape of rectangular cross section by the machining for ensuring the shape and accuracy (method 2). A hump 7 is formed on a bead seat part 6 of a rim 8 having the curls 4 of rectangular section at both ends obtained in this manner, a water drain hole 9 is formed in the curls 4, a valve hole 11 for sealing air for the tire is opened in one drop inclination part 10, and a disk is fitted in the cylinder of the rim 8 to obtain the two-piece wheel.
KIMURA SHIZUO
KATO IKUO
