| 摘要 |
PURPOSE:To form toothed parts with a high mass-producing property by inserting a material between the upper and lower die sets, punching a core hole of the parts and punching a prepared hole, based on its core hole as a reference, working a rough tooth part to one side of the prepared hole and working a final tooth crest shape, and punching the whole periphery of an external form. CONSTITUTION:A material M is inserted into an annular groove 19 under a neck of a lifter pin 14 and fed, a core hole of toothed parts is made by a core hole punching punch 1, and also, a pilot use hole is made by a pilot punch 2. Subsequently, an arc- shaped prepared hole corresponding to the outside periphery of a tooth crest part is punched by a prepared hole punching punch 3, and also, a rough tooth part hole is punched in the material M by a rough tooth part punching punch 4. As for the material M which has been fed between a finish punching punch 5 and a finish use counter 6, when the upper die set 102 descends, the material M which has been punched goes into a die bush 85. A partially fabricated item is pressed in the die bush 85, and toothed parts having high accuracy, from which a draft has been eliminated entirely are manufactured by one reciprocating process of the finish use punch 5 and the counter 6. |
