To provide a method for easily manufacturing a square pipe-like molded product having proper shape by molding a pipe-like metal material.
The manufacturing method includes: a preliminary molding step for molding the pipe-like metal material W so as to have the peripheral length substantially the same as that of a square-pipe-like molded product S; a fluid injecting step for injecting a fluid into the metal material W; and a pressurizing molding step for pressurizing the metal material W from the surrounding by using an upper die 3 and a lower die 4, and molding it so as to have a shape corresponding to the cavity surface 8 of the molding die 5 while controlling an internal pressure of the metal material W. In this method, the internal pressure of the metal material W which is controlled in the pressurizing molding step is controlled at a value capable of resisting an external force to be applied to the metal material W to prevent buckling from being generated in the metal material, and is controlled at a value capable of preventing a corner portion of the square pipe-like molded product S from excessively expanding.
JPS5719114 | METHOD FOR FORMING HYDRAULIC BULGE OF ELBOW |
WO/2021/029392 | DISPLAY DEVICE AND SHAPING DEVICE |
Masataka Otani
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