METHOD FOR MACHINING STEPPED FLANGE AND ITS DIE FOR THIS METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for machining a stepped flange in which a blank punched from a plate material is set at a lower die, an outer side of this blank is held with an upper die and a lower die and compressed, thereafter in the case that a trim work is applied for arranging its outer shape, this amount of trim is reduced and its surplus state can be restricted. SOLUTION: An outer extremity end of an upper die 3 is provided with a protrusion 4. A lower die 2 is formed with a slant surface 5. Material at the outer side of a blank depressed and flowed out with the protrusion 4 of the upper die 3 is pushed out along the slant surface 5 formed at the lower die 2 so as to restrict an outward flow.