| 摘要 |
PURPOSE:To prevent cracking and breakage and form a formed product having an uniform thickness with pressurized gas by a method wherein a desired position of a portion to be formed is softened locally in a forming work of a thin metallic plate. CONSTITUTION:In case a thin plate 2 is press-formed between a forming die 1 and a plate pressing metal member 3 by a gas pressurizing method, preventing leakage of pressurizing gas by 0 ring 4. A plurality of nozzles 8 for gas burners are provided on the plate pressing metal member 3 at an upper portion 3a of a chamber and nickel chrome wires 9 for ignition are arranged adjacent to the nozzles, thereby the thin plate 2 is heated and softened locally. The fuel gas is introduced from a gas cylinder as a mixture of oxigen and propane gas or the like through a switching valve 7. An outer rim portion of a thickness softened locally by heat softening is elongated by the pressure mainly. |
