PURPOSE: To support surely a reinforcing member in dies with excellent operability by projecting downward the lower part of a top die in the part facing the cavity, and forming continuously the inside circumferential groove surface in an annular hollow groove for detaining the reinforcing member.
CONSTITUTION: A reinforcing member 31 is placed in the hollow groove 33 of a bottom die 2 divided in a die open state and thereafter a top die 1 and the die 2 are clamped in the case of forming a reinforced piston. The member 31 is detained and supported in the groove 33 by clamping of the die 1 and the die 2, by which the die is loaded and set in the cavity 12. The loading and setting of the member 31 into the cavity 12 are thus accomplished by placing only approximately the lower half of the member 31 in the groove 33. The loading of the member 31 is thus accomplished more easily and quickly as compared to the prior art.
OGASAWARA AKIHIKO
HIROSE MAKI
YAMAGUCHI FUMIO
