DIE FOR MANUFACTURING HOLLOW FORGES WITH TWO SIDE PIPES Russian patent published in 1994 - IPC

FIELD: production of forges. SUBSTANCE: die has piercing punch with annular pressure bead having two inclined surfaces disposed adjacent to working end to form symmetrical wedge with an angle of 100-140 deg. between its surfaces, two half-dies defining central and two side cavities, where side punches are disposed. Half-dies have joining plane extending through axes of side cavities. Piercing punch is mounted in such a way that each inclined surface of wedge is positioned adjacent to side cavity of half-dies. Inclined surfaces of piercing punch wedge may made convex or concave. EFFECT: simplified construction and enhanced reliability in operation. 4 cl, 2 dwg