Method of manufacturing a laminated ring and apparatus for measuring the circumferential length difference of a ring in such a method

摘要

A laminated ring 6 is manufactured by severing a cylindrical drum 2, which comprises a sheet 1 of maraging steel with welded opposite ends, into a plurality of rings 4 of predetermined width, rolling the rings 4 to a predetermined target circumferential length, correcting circumferential lengths of the rings 4 aging and nitriding the rings 4, and laminating the rings 4 into a laminated ring 6 for transmitting power in a continuously variable transmission. A load applied to a circumferential edge of each of the rolled rings 4 and a load applied to another circumferential edge thereof are measured while supporting an inner circumferential surface of the ring 4 and applying a tensile load in a direction to expand the ring 4. The difference between circumferential lengths of the circumferential edges of the ring 4 is detected based on the difference between the loads applied to the circumferential edges when the difference between the loads is maximum. <IMAGE>