变曲率沟槽高精度球体精研工艺优化实验研究

Research on optimization experiment for precision balls with variable-radius groove in finishing process

基于变曲率沟槽研磨抛光方法,对球体进行运动学分析并建立运动学方程。利用Matlab绘制球体表面加工轨迹并结合Preston方程建立球度误差计算模型。仿真结果表明最短的加工时间为26 h。基于田口法对精研阶段球体加工工艺进行正交试验,并对实验结果进行方差分析及S-N-K分析,优化各加工阶段加工参数以获得最优的圆度值。结果表明:在半精研阶段将球体的球度研磨至0.7μm,精研阶段研磨至0.3μm时加工效率最高。完成精研阶段(半精研、精研和超精研)阶段只需要29 h,相较于传统的加工方法其效率提高了14.7%,并且抛光结束后的氧化锆陶瓷球粗糙度达到14 nm,圆度达到0.13μm,达到了G5级国家标准。

The kinematics equation of the ball is established through theoretical analysis based on the variable-radius groove polishing method. The processing trajectory was plotted using Matlab, and the spherical error calculation model is established with the Preston equation. The result shows that the shortest processing time is 26 hours. The orthogonal test was done based on Taguchi method, then the analysis of variance (ANOVA) and Student-Newman-Keuls (S-N-K) posttest were utilized for the optimization of different stage processing parameters to obtain the highest roundness. The results can be concluded that the highest lapping efficiency can be achieved when the sphericity reach to 0.7 μm after semi-finishing, and 0.3 μm for finishing process. It takes only 29 hours including semi-finishing, finishing, ultra-finishing stages, comparing with the traditional method the efficiency improved 14.7%. Meanwhile the final roughness and sphericity of high precision Zirconia ceramic balls were 14 nm and 0.13 μm respectively, achieved the G5 grade of national standard.