螺旋沟槽属于复杂的空间螺旋面,砂轮与刀具的相对运动复杂,在微细立铣刀的制造过程中耗时最长、难度最大,精确、高效加工螺旋沟槽成为微细铣刀制造过程亟须解决的关键问题之一。基于无瞬心包络原理研究了微细铣刀螺旋沟槽的刃磨过程,提出一种微细螺旋铣刀轴向型线的计算模型,该模型避免了利用接触公法线求解时,因砂轮截形上的奇点和圆滑二次曲线导致无法求解的情况,计算过程与求解简单,适用于对砂轮廓形复杂时刃磨求解。在所建模型基础上分析了砂轮形状和加工参数对螺旋槽型形状的影响,以及砂轮摆角和前刀面宽度对径向前角的影响。通过刃磨验证了模型与分析的正确性,试验证明实际加工的微细铣刀沟槽截形与包络计算的沟槽型线几何形状参数吻合良好。
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.