摘要 |
A process for producing hollow one-piece elements having a highly curved lateral wall from metal, in particular copper or copper alloy, pipes. A cylindrical pipe is widened via permanent deformation between two appropriately shaped dies (9,10), by simultaneously applying hydraulic pressure directly inside the pipe (2) and axial pressure on the opposite ends (16,18) of the pipe; the required finished shape being achieved in successive stages, by inserting inside the dies (9,10) molds (20) having a predetermined profile and of gradually increasing size. |