| 摘要 |
PURPOSE:To prevent waste of a material, while maintaining strength of a function and to reduce the weight of a device, by a method wherein, a disc, on the periphery of which a gear portion forming part is provided, and a laminar ring, on the periphey of which a gear portion forming part of the same shape is provided, are firmly secured to each other so that the gear portion forming parts coincide with each other. CONSTITUTION:A disc 13, which is press-molded as a prime forming part, has a corrugated gear portion forming part 13a along its periphery. A laminar ring 25, which is press-molded in the same manner described in the disc 13, is brazed to the joining surface of the disc 13. Namely, the laminar ring 25 has a gear portion forming part 25a formed in the same shape as that of the gear portion forming part 13a of the disc 13, and the gear portion forming parts 25a and 13a are superposed on each other so that they coincide with each other to form a gear portion 27 of a sprocket 11. This eliminates a lightening work, resulting in the ability to manufacture it at a low cost. |
