| 摘要 |
PURPOSE:To part easily forming goods, to reduce a distortion of the forming goods, and to increase a forming draft by forming a gap by which the outside edge part of a plate to be formed can be inserted into a female metallic die without pressure, in a forming metallic die of a superplastic metallic plate by a fluid pressure. CONSTITUTION:A female die 11 having a product die recessed part 12, and an opposed metallic die 13 having a feed port 14 of a pressurized fluid are combined by each clamp part 15, 16. A circumferential groove part 17 is formed in the circumferential edge of the recessed part 12, and the circumferential part 17 has a gap by which the outside edge part of a plate to be formed 18 can be inserted without pressure. That is to say, this gap has a size of at least a thickness of the plate 18. Accordingly, the plate 18 can be formed freely without being restricted by the metallic die. Also, the plate 18 and the female die 11 are made to adhere tightly to each other by a fluid pressure at the time of forming, therefore, it is not feared that a fluid leaks. However, if said gap is excessive, said fluid leakage is apt to occur, and a function for suppressing wrinkles cannot be fulfilled, therefore, an air-gap in case when the plate 18 has been inserted into the circumferential groove part 17 is set to a prescribed range. |
