| 摘要 |
PROBLEM TO BE SOLVED: To easily obtain, by bulging, a curved hollow body in which the middle part in the longitudinal direction is bent downward and/or upward. SOLUTION: On the mating surface of the upper and lower dies 21, 22, there are provided the upper and lower forming faces 21b, 22b that are bent downward and/or upward in the middle in the longitudinal direction and that have a prescribed cross section; after the hollow body 4 to be worked (the workpiece) is placed on the lower die, the workpiece is closed at both ends with a punch 25; liquid is force-fed into the workpiece, with the upper die lowered; and the workpiece is compressed in the axial direction with the punch, making the middle part of the workpiece bent downward and/or upward and also deformed in the cross section into a prescribed shape; thus, the curved hollow body is provided.
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