METHOD AND TOOL FOR EXTRUDING HOLLOW TUBULAR BLANK Russian patent published in 1998 - IPC

FIELD: plastic metal working, namely technique of cold backwards extrusion of tubular blanks of non-ferrous and noble metal alloys. SUBSTANCE: method of extruding hollow tubular blank comprises steps of setting tough lubricating insert into cavity of ejector. Said cavity is placed in lower portion of container duct. Blank is arranged on said insert for cold backwards extruding of cavity and piercing it at one stroke of needle-punch. Tool for performing the method includes container having in lower portion of its duct ejector provided with cavity in its upper portion. Cylindrical tough lubricating insert is arranged in cavity of said ejector. The last is built-up one, it has head secured by means of bolt and set of plate springs. Tough lubricating insert is arranged on head of said ejector for placing blank. Cavity is formed by means of needle-punch. Said ejector has radial ducts and grooves opened to upper end of ejector. EFFECT: enhanced efficiency, increased factor of metal use, lowered specific loads at deformation. 2 cl, 5 dwg