| 摘要 |
A method of manufacturing a cylindrical part which has a number of small holes on its wall or the one having a bottom. The method comprises a punching process of forming a punched pattern having zigzag portions extending in radial directions and connection portions by which the zigzag portions adjoining each other are connected, and a drawing process of extruding the punched metal plate obtained by the punching in such a way that the punched pattern forms a cylinder or a part of a cylinder and that the zigzag portions are expanded. According to this invention, a cylindrical part which has a number of small holes on its wall or the one having a bottom can be so worked easily as to have a predetermined depth through one or two processings, and so the reductions of the manhour and cost can be attained. |
