| 摘要 |
PURPOSE:To manufacture a semi-circular member having a finishing margin, by pressing down a ring material having a diameter a little larger than the intended radius, and by dividing it into two pieces upon giving the circular part the desired dimension. CONSTITUTION:A ring material 31 with a size a little larger than the intended radius is processed into a specified width t using a ring rolling mill etc. Then it is pressed down for a distance equal to the specific dimension b to provide a long circular material 33, in which the radius r of the circumferential part will be the intended radius. A semi-circular material having a finishing margin a is now obtained by dividing this long circular material 33 in the short dia. direction into two pieces. |
