| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic forming method and a hydraulic forming apparatus which can improve productivity by eliminating the retention time of die clamping for a blank during forming, and can suppress equipment investment to reduce production cost by using a general-purpose mechanical press.SOLUTION: By using a first drawing die, a first convex die is lowered against a first concave die to a bottom dead center to press a plate-like blank, so that the blank is previously processed to the stage of an intermediate formed article (x), in which a liquid storage part (a) is formed on a concave side, in the middle stage of forming a product shape. Then, by using a second drawing die N, the intermediate formed article is set on a concave surface part 20 of a second concave die N1 with a cavity S located below and with the liquid storage part facing upward. After a liquid W is injected into the liquid storage part, the peripheral edge part of the intermediate formed article is pressed, and die clamping is performed. At the same time, a second convex die N2 is lowered against the second concave die to a bottom dead center. Thus, the intermediate formed article is pushed into the cavity and pressed along the concave surface part of the second concave die by liquid pressure generated between the intermediate formed article and a convex surface part 25 of the second convex die. Thereby, the remaining part of the forming process is immediately performed to the stage of a final formed article X in the product shape. |
