JPS54143760A - Drawing die for metal - Google Patents

Abstract

PURPOSE: The simply constructed die which can complete the deep drawing through one pass, by forming the projection thread at the conical part of the truncated conical punch.

CONSTITUTION: At the conical part 10 of the drawing punch whose head is formed into a truncated cone, plural projecting threads with approximately triangular section are formed on the planes vertical to the axis of the punch. These projecting threads can be formed into the ring type 11, the segments 12 separated into plural pieces, or the ring type thin tongued and grooved face 13. This punch is pushed down to thrust the blank 16 being held by the die 14 and the blank-holder pad 15; hereby, the drawing is given to the blank 16 starting at the corner part at the tip of punch. By further pushing down the punch, the blank 16 contacts with the projecting thread 11' of the punch and then is penetrated; after that, the blank 16 is pressed by the penetrated part, so that the enlongation between the projecting threads 11' is reduced from the corner part at the tip of the punch, being locally elongated until then. Similary, the blank 16 is penetrated by the projecting thread 11 and the elongation of the blank 16 between both projecting threads 11, 11', is reduced. Hereby, the elongation is dispersed and the breaking of the blank 16 at the corner part of the drawn bottom plane is prevented.

COPYRIGHT: (C)1979,JPO&Japio