HOLLOW PRODUCT PRESSING TOOL Russian patent published in 1999 - IPC

FIELD: plastic working of metals. SUBSTANCE: pressing tool has container with mandrel, die, stamp, and pressure plate mounted on stamp, with all parts mentioned being placed inside container. Working surface of pressure plate and die entry part are made inclined. Inclination angle of pressure plate working surface generatrix is determined from formula: , where L(ni) is inclination angle of pressure plate working surface generatrix at distance ri from container axis, deg; L(mi) is inclination angle of die entry part generatrix at distance ri from container axis, deg; D(d) is diameter of die opening, mm; D(c) is diameter of container, mm; d(m) is diameter of mandrel, mm. Mandrel has bead. Mandrel bead and side surface junction portion is made curved in accordance with profile of opposite part of die. EFFECT: increased efficiency by reduced height of remainder of billet and by preventing pressed product from development of fractures on its inner surface. 1 dwg, 1 ex