| 摘要 |
PROBLEM TO BE SOLVED: To realize light weighting of a product by molding with a high fluid pressure, wherein at least one end face ranging to a flange part is hollow, having a swelling at the hollow part and its thickness is almost even at one cross section. SOLUTION: At a portion ranging to a molding die, a high fluid pressure is generated with a slide of a press machine for energizing a metallic material with the high fluid pressure so as to perform a molding by flowing the metallic material into a die cavity. It is desirable that a high fluid pressure is three times or more than a deformation resistance of the metallic material. When an upper die 5 descends, a fluid is compressed with an action of a piston 7 and a high fluid pressure chamber 17 is formed downwards. This high fluid pressure acts on the material and the material is flowed in a cavity 13 so that the material is molded into a crank shaft 1. At a stage where a sufficient space is created between a bottom block 14 and an upper block 10 when the upper die 5 is ascended accompanied by a slide, the crank shaft 1 remained in the bottom block 14 is pushed out from the bottom block 14 by an action of a knockout pin 16.
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