| 摘要 |
PROBLEM TO BE SOLVED: To prevent cracking of a green compact caused by difference of spring back quantities among respective punch elements at the time of releasing compressive load. SOLUTION: After compression molding is finished, the green compact W is held between an upper punch 4 and a lower punch 5 and is taken out of a die 2 while pressing an upper surface side of the green compact W by the upper punch 4 under pressure holding load smaller than molding load. At that time, a first punch 9 and a third punch 11 constituting the lower punch 5 are pushed up by prescribed quantities respectively by adjusting cylinders 33, 34. Thus, difference of spring back quantities between the first and third punches 9, 11 and the second punch 10 is absorbed. |
