DIE FOR OPEN VOLUMETRIC FORMING WITH EXPANDING FLASH BRIDGE Russian patent published in 2020 - IPC B21J13/02 

FIELD: metal forming.

SUBSTANCE: invention relates to metal forming and can be used in making dies for open forging of axially-symmetric forgings without inner cavity punching into butt end. Die includes upper and lower halves made with engravings forming preliminary and final grooves. Final groove is made with a hollow groove for displacement of excess metal in the final groove having a magazine and a diverging flash bridge. Flash bridge is made with a slot in the place of the groove, which is filled in the last turn, and with one-sided expansion having the profile of curvilinear shape. Shape of the profile is defined taking into account equal volume of metal displaced from the groove in the hollow at the last stage of pre-dampening (V_pd), and volume of the flash bridge (V_fb) at the initial height of the flash bridge h_hb, equal to the thickness of the shin h_s, taken taking into account the press force. At that V_pd is not more than half the flash volume (V_fb).

EFFECT: result is reduced metal consumption and forcing force and increased durability of tooling.

1 cl, 3 dwg