DRAWING LARGE-SIZED COMPLEX-SHAPE PARTS (VERSIONS) Russian patent published in 2015 - IPC B21D22/26 B21D37/00 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, namely, to sheet stamping. Sheet blank is placed on dual- or triple-action press die including female die with working cavity, pressure surface and extractor, pressure plate and male die. Sheet blank edge is pressed by die pressure plate to female die pressure surface to pull sheet blank central part by male die into female die cavity along with deceleration of blank edge by pressure plate. At termination of drawing and start of male die exit from female die, compressed air is fed through male dire holes to semi-finished product sections, bonded via grease with male die surface and tightly abutting thereon, to uncouple said sections from male die surface to follow said male die. Or, at termination of drawing and female die and pressure plate upward stroke start, compressed air is forced via male die orifices to semi-finished product sections, bonded via grease with male die surface and tightly abutting thereon, to uncouple said sections from male die surface to follow said male die.

EFFECT: higher precision and quality.

2 cl, 2 dwg