METHOD FOR TURNING BLANK OF PISTON OF INTERNAL COMBUSTION ENGINE IN LATHE

processes for turning in lathes high-accuracy articles with complex geometry of outer profile, namely turning blanks of pistons of internal combustion engines. SUBSTANCE: method comprises steps of mounting and basing piston blank in lathe with use of basic members, semifinishing and finishing it at turning chamfered grooves for piston rings, turning skirt surface and boring hole for piston pin; before making chamfered grooves, turning end of blank bottom. At turning bottom end, chamfered grooves and skirt surface, blank is mounted due to coaxial cantilever-type fixation on flanged mandrel in rotating lathe spindle. At boring hole for piston pin blank is mounted on lathe working table performing translation motion. Blank is based on mandrel according to two basic points arranged at sides of hole for piston pin directed to skirt surface and according to reciprocal points for resting basic members of blank (at inner side of skirt) upon basic plane of mandrel flange, said plane is normal relative to spindle axis. Blank is based on working table according to basic points of blank basic members arranged at opposite sides of working table, according to reciprocal points for resting blank bottom end upon surface of working table of lathe and according to orientation points of basic members of blank outer surface. Orientation points are arranged at opposite sides of hole for piston pin in order to prevent turning over of blank at working. EFFECT: enhanced quality of worked blanks of pistons. 2 dwg