Grinding Analysis for Helical Groove of Micro Mill Based on Non-instantaneous-pole Envelope Principle

Helical groove is complex spatial helical surface. Because the complex relative motion between grinding wheel and the tool, which is the most time-consuming and most difficult manufacturing process of micro end mills, accurate and efficient processing of fine helical groove cutter become a pressing problem. Based on the principle of non-instantaneous envelope theory, the grinding process spiral groove millers are studied and a computational model of spiral miller axial line which can void the situation that it cannot be solved because of singularities and sleek shape of the cut-off wheel when contact normal line theory is applied. The effect of wheel shape and process parameters on shape of spiral groove and the effect of swing angle and rake width on radial rake angle are analyzed based on this model. In addition, the analysis is valid by the grinding experiment and the practical shape of micro miller and geometry shape of grooves truncate calculated by envelope are in good agreement.