| 摘要 |
PROBLEM TO BE SOLVED: To obtain a method for forge-shaping a holey part capable of forge- shaping a holey part with a simple process. SOLUTION: In a cutting process, a columnar stock 1 is cut so as to become an upsetting ratio of L/D=1.5-2.0. In a first process, the columnar stock 1 is shaped by upset forging in accordance with the outer shape of a nut. The height h of the intermediate product 2 is shaped lower than the height H of the final product 4. Next, in a second process, blind holes 3a, 3b are extruded from both sides. The depths of both blind holes 3a, 3b are different, and one side of blind hole 3a is shaped deeper. The height of the intermediate product 3 in the second process is shaped into the nearly same as the height of the final product 4. In third process, the deeper blind hole 3a side is punched and blind holes 3a, 3b are allowed to communicate.
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