| 摘要 |
<p>PURPOSE:To improve the quality and productivity and at the same time to lower the production cost, by molding only the outer circumferential surface of a drum with a forging process to minimize said process and molding a blank material with a die casting process. CONSTITUTION:A blank material 1 contains a bottomed cylinder 1a, a bottom circular plate 1b and a downward cylindrical part 1c and has a diameter slightly smaller than a finished product. The material 1 consists of a prescribed composition and is molded with a die casting process and has pinholes or flaws on its entire surface. As shown by imaginary lines, the pressure molding is applied to the cylinder 1a by means of a forging process. Thus the diameter of the outer circumferential surface 1d is slightly increased, and at the same time a working structure is formed to obtain the 2-3mu roughness on the surface 1d. And a hot forging process is best for formation of the working structure. After the formation of the working structure, a surface treatment is applied to coat the surface 1d with a thin film of metallic soap, etc.</p> |
