HERSTELLUNGSVERFAHREN FÜR EINEN HOHLRING MIT KÜGELCHEN UND GUSSFORM ZUR VERWENDUNG DAFÜR

摘要

A metal mold is disposed adjacent to the outer circumference of a base ring, and has a molding face in the inner circumference and a plurality of grooves for forming beads on the molding face along the circumferential direction. A coil for electromagnetic forming is disposed adjacent to the inner circumference of the base ring. When a momentary large current is applied to the coil in this arrangement, the diameter of the base ring is expanded by pressing the base ring toward the molding face of the metal mold such that the base ring is molded into a shape corresponding to the molding face by electromagnetic forming. Improvements such as a metal mold capable of degassing, a separable metal mold, roll-correcting after electromagnetic forming, application of momentary large current over several times, a metal mold with a cutting blade, use of a base ring with a large number of holes, and a metal mold with positioning means are then added. With these improvements, a highly accurate cylindrical ring with beads can be produced at low cost and with high productivity.