METHOD FOR KNURLING PRELIMINARILY CUT THREAD Russian patent published in 2005 - IPC

FIELD: machine engineering, namely forming threads by plastic deforming, for example knurling thread by means of rollers.

SUBSTANCE: method comprises steps of knurling with use of built-up roller having three portions namely: two supporting portions and one deforming portion arranged between supporting ones. Supporting portions are rigidly mounted on spindle; deforming portion is movably mounted in splines whose direction is inclined by angle 45° relative to lengthwise axis. There is gap h between supporting and deforming portions. Width of said gap is equal to thickness difference of deforming and supporting turns. At knurling left side of thread profile of blank, gap h is self-aligned on the right from deforming portion and at knurling right side of thread profile of blank gap is self-aligned on the left from deforming portion due to changing rotation sign of spindle and axial motion of movable deforming portion in inclined splines. Invention provides efficiency of process increased by 1.8 - 2 times, strength of tool increased by 2.5 - 3 times, height of roughness of thread surface lowered by 1 - 2 classes, cost price of process reduced by 2 times.

EFFECT: enhanced efficiency, reduced cost price of process.

3 dwg, 1 ex