METHOD FOR CUTTING OFF HEADS OF ROD ARTICLES AND TOOL FOR PERFORMING THE SAME Russian patent published in 2007 - IPC B21K1/50 B21J13/02 

FIELD: plastic working of metals, possibly manufacture of rod like fastening articles with heads having curvilinear supporting surface, such as clamp bolts for joining rails of railway road.

SUBSTANCE: cutting off operation is realized by means of tool having die, punch and knocking out member. Rod portion of blank of rod article is placed in hole of die having recess. At initial stage of cutting off operation by action of punch upon end face of head the last is embedded into cut-off die. Then simultaneously punch and cutting edges of die are cut into body of head at clamping cut-off metal between end surfaces of punch and die. Said cut-off metal is separated from head by pushing rod article through opening of punch. Cutting edges of die are cut into bode of head by depth consisting of 0.65 - 0.80 of height of article head while preventing contact of faces of head part placed between cutting edges of die with die surface. Distance between cutting edges of die providing cutting-off of mutually opposite faces of head consists of 0.95 - 0.99 of similar distance between cutting edges of punch. Height of die recess consists of 0.65 - 0.80 of head height.

EFFECT: improved quality of articles, enhanced strength of tool.

2 cl, 4 dwg