| 摘要 |
A method for forming sheet metal articles, such as automotive body panels, having complex curvatures. Opposing, complementary, pre-form and finish-form tools are used in a single press. A sheet of hot blow-formable sheet metal alloy, heated to a forming temperature, is placed between the tools. The pre-forming tool is lowered to a first stage closed position thereby trapping edges of the sheet between binder surfaces of the tools. The sheet is first stretched against the pre-form tool using pressurized gas to form a pre-form that undergoes most of the metal stretching required for the final part shape. Then the finish-form tool is pivotably advanced into a second stage closed position. The pre-form is displaced away from the pre-form tool and hot plastically formed against the opposing finish-form tool with pressurized gas to obtain the final sheet metal part shape. The finish-form tool is then pivotably retracted so as to avoid die lock or part interference conditions.
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