| 摘要 |
PURPOSE:To prevent occurrence of cracks in forming members at the time of forging and simplify the constitution of the die, by constituting the forming hole in the die body with plural forming members and, at the same time, by installing a hole through which a knockout pin is inserted, to the lower part of the forming hole. CONSTITUTION:A forming member 12 is fitted to the upper half part 2a of a reception hole 2 in a die body 1 and a forming hole 4 having a nearly hexagonal cross section and a knockout pin inserting hole 6 communicating with a concaved part 7 and the forming hole 4 are formed on the center line of the forming member 12. Moreover, the forming member 12 is equally divided into six parts by three planes containing the central axis of the hole 6 and two angular parts of the forming hole 4 which are opposed to each other, respectively, and each split piece 12a is closely contacted with each other. Since each split piece 12a can be deformed individually against elastic force when a nut is forged by placing a metallic material having a nearly cylindrical shape in the forming hole 4 and by pressing the metallic material with a pressure pin, the breakage of the forming member 12 by the angular part of the forming hole 4 can be prevented. |
