| 摘要 |
PURPOSE:To form an end plate unified with a nozzle by forging a circular disk from a steel ingot, pressing in a tapered ring to form an annular groove, extending the outside of the groove to form a flat tabular blank, heating the blank and pressing to specified shape. CONSTITUTION:A steel ingot is formed successively to a circular disk by upset forging. A tapered ring 2 having inner diameter nearly equal to outer diameter of the nozzle of an end plate is put at the center, and pressed in applying downward force. Outer part of the annular groove 1a thus formed is forged and extended to form a blank 3. Next, the blank 3 is heated and placed on a lower die 4 and pressed by an upper die 5. At this time, a concavity 4a having curved face corresponding to the tank head to be formed is provided, and a relief 4b for the nozzle is provided at the center of the concavity 4a. The upper die 5 has a convex curved face corresponding to the end plate to be formed, and the diameter is made smaller than inner diameter of the end plate. Thus, contact area with the blank 3 is small, and no ironing is performed. Accordingly, forming is possible by small pressing force. |
