| 摘要 |
PROBLEM TO BE SOLVED: To provide a die assembly for molding a green compact with a shape in which boss parts and a rim part are connected with a plurality of arm parts and with a structure using a lower punch with a horn part, in which cracks are hard to occur at the root of the horn part, and whose service life is held for a long period of time. SOLUTION: In the die assembly for molding the green compact 60 with a shape where boss parts 62a, 62b, and a rim part 64 are connected with a plurality of arm parts provided between adjoining flange holes 65, a die 10 and a core part 20, a lower punch 41 with the horn part 42 supported to the lower ram side and an internal lower punch 40, an external upper punch 31 having a horn part guiding hole 32 fitted to the horn part 42 supported to the upper ram side and an internal upper punch 30 are provided, and further, in a state where the respective punches are arranged at powder compression completion positions, the clearance between the horn part 42 on the lower punch with the horn and the horn part guiding hole 32 on the external upper punch side is larger at the vicinity of each edge part located in the horn part circumferential direction than that at the inside part and the outside part in the horn part 42. COPYRIGHT: (C)2007,JPO&INPIT
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