| 摘要 |
PURPOSE:To improve the strength of a gear manufactured by sintering and forging by shearing a sintered preform of a larger diameter to the shape of a gear and compressing the resulting gear to provide the desired shape as well as to increase the density. CONSTITUTION:A sintered preform 12 whose diameter is larger than the diameter of the through hole 22 in dies 2 is prepd. The preform 12 is set on hold pins 8 projected from the top of the dies 2 so as to leave an interval between the preform 12 and the dies 2. An upper punch is then lowered to shear the preform 12 to the normal shape of a spur gear together with the dies 2 and the resulting spur gear is compressed by further lowering the punch to increase the density.
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