Method and device to produce an annular workpiece of sheetmetal.

摘要

The invention permits the manufacture of annular components such as shroud collars on which machining is to be carried out. The method consists in bending a presized metal sheet by means of a series of internal bearing elements (8) mounted on a rotary plate (6) and by means of a pressure roller (4) bearing on the outer surface of the metal sheet (2). A complete rotation of the rotary plate (6) permits the complete bending of the metal sheet (2) into the shape of a shroud collar. The second main operation consists in carrying out, on the device itself, the welding operation for joining the two ends (1, 3) of the metal sheet (2). This method enables any prior machining to be carried out on the presized flat metal sheet, without these machining operations being impaired by the bending or welding operation. Application to the manufacture of front casing collars shroud surrounding the colder duct of a bypass turbojet. <IMAGE>