APPARATUS FOR KNURLING LARGE-SIZE OUTER THREADS Russian patent published in 2005 - IPC

FIELD: manufacturing processes in machine engineering, namely apparatuses for forming outer large- and mean-size threads by plastic deforming in blanks of highly ductile materials.

SUBSTANCE: apparatus includes at least three thread knurling rollers that are mutually joined through rigid kinematic connection and subjected to positive rotation and two punches. Rollers have multi-start thread whose profile corresponds to that of knurled thread. Two punches are provided with thrust bearing assemblies and they act upon ends of blank one towards other for deforming blank. One punch is floating stop that allows compensate axial motion of blank. Diameter of thread knurling rollers is selected in such a way that rollers may impart to blank axial motion only in direction towards floating stop and it is normalized by means of mathematical expression. Invention provides efficiency increased by 2 - 3 times, strength of tool increased by 1.5 - 2 times, roughness of surface improved by 1 - 2 classes.

EFFECT: enhanced accuracy and stability of thread size, possibility for knurling rectangular, trapezoidal and other threads at enhanced efficiency and quality.

2 dwg, 1 ex