COMBINED MILLING METHOD BY MEANS OF NEEDLE MILLING CUTTER AT STRENGTHENING OPENINGS Russian patent published in 2007 - IPC B23C3/00 

FIELD: manufacturing processes in machine engineering, working materials by cutting.

SUBSTANCE: method comprises steps of imparting lengthwise feed to tool having body with seats provided with turning on their inner surfaces for freely mounting bushings with working surfaces in the form of wire pile bundles and imparting rotation to blank. In order to enlarge manufacturing possibilities due to controlling depth of cut-off layer and micro-relief of worked surface, tool is used in seats of which additional bushings are arranged for preliminarily knurling of worked surface and for surface plastic deforming. Said bushings are arranged according to blank rotation sign in next succession: bushing for preliminarily knurling, bushing with pile bundles, bushing for surface plastic deforming. Tool body is in the form of mandrel with radial seats having rectangular cross sections. On outer surface of bushing whose shape is reciprocal to that of seat shoulder is formed. In turning of seats for bushings with pile bundles compression spring is arranged. Said spring rests upon shoulder of bushing and creates static load at needle milling. In turnings of seats for bushings used for preliminary knurling and for surface plastic deforming, compression spring and ring are arranged. Said spring displaces bushings to center of tool and it rests upon said shoulder of bushing. Ring is arranged on periphery of mandrel and it has openings for working surfaces of sleeves. Bottom of bushings is inclined by acute angle to plane normal relative to lengthwise axis of bushing and it engages with cone surface of wave-guide arranged in central lengthwise opening of mandrel. Striker acts upon end of wave-guide and it creates pulse load acting upon bushings. Striker is mounted in central lengthwise opening of mandrel along the same axis and it is driven from hydraulic pulse generator. Helical cylindrical compression spring acts upon opposite end of wave-guide. Radial extension of bushings is regulated by means stop limiting lengthwise motion of wave-guide at side of said spring.

EFFECT: enlarged manufacturing possibilities of method.

5 dwg, 1 ex