MANUFACTURE OF METAL-MADE CURVED LONG LENGTH HOLLOW BODY BY APPLICATION OF INNER HIGH PRESSURE THERMOPLASTIC DEFORMATIONPROCESS AND PRESS FOR SAID DEFORMATION

摘要

PURPOSE: To produce an elongate hollow body in which a cross sectional contour are varied impossible in a conventional method by bending a sheet-metal blank in the plane vertical to the sheet-metal blank when progressing a closing action of an internal high pressure plastic deformation press. CONSTITUTION: Stock portions 2, 3 are overlapped each other, the overlapped stock portion is subjected to roller seam welding continuously in the region of a continuous joining portion 4 over a whole length. The integrally joined sheet-metal stock is introduced into an internal high pressure plastic deformation press and is bent by the plane vertical to the sheet-metal stock in progressing a closing action of the press. Next, the sheet-metal stock is expanded by introducing a pressure medium between both stock portions 2, 3, when expanding, both stock parts are abutted on the inner face of the internal type high pressure plastic deformation tool which has the outside profile of the elongate hollow body for its inside profile. A cleaving graver with a supply hole is used for a pressure supply tool to between both stock portions.