研磨驱动方式和转速比对磨粒运动轨迹的影响研究

Influence of lapping drive mode and rotational speed ratio on the track of abrasive particles

针对常规平面研磨过程中磨粒运动轨迹重复性较高、研磨抛光均匀性不足的问题,引入了无理转速比概念,以进一步提升研磨加工均匀性。建立了定偏心主驱动式和直线摆动驱动式下的轨迹数学模型,通过Matlab进行了运动学仿真,对两种驱动方式和不同转速比下的单颗与多颗磨粒运动轨迹进行了对比研究,最后用离散系数对两种驱动方式在不同转速比下的研磨轨迹均匀性进行了分析。研究结果表明:当转速比为有理数时,研磨轨迹重复,转速比大小与驱动方式对轨迹均匀性影响较大;而当转速比为无理数时,研磨轨迹开放不闭合,其轨迹均匀性优于有理数的,且转速比大小与驱动方式对轨迹均匀性影响较小;该研究为选择合理的驱动方式与转速比提供了理论依据,有利于工件被加工表面质量的提高。

Aiming at the problem that the abrasive grain trajectory was highly reproducible,and the lapping and polishing uniformity was insufficient in the conventional lapping process,the introduction of irrational speed ratio of this new concept,was expected to further enhance the lapping process uniformity. The mathematical model of the trajectory of the eccentric main drive and the linear swing drive was established,and the kinematics simulation was carried out by Matlab. The trajectory of single and multiple abrasive grains were compared between two driving modes and different speed ratios. Finally,the uniformity of lapping trajectory at different speed ratios was analyzed by discrete coefficient. The results indicate that when the speed ratio is rational,the lapping trajectory are repeated,speed ratio size and drive mode have a great influence on the trajectory uniformity; when the speed ratio is irrational,the lapping trajectory are open,its trajectory uniformity is better than the rational number,and the speed ratio and driving mode have little effect on the trajectory uniformity. The research provides a theoretical basis for selecting reasonable driving mode and speed ratio,and is beneficial to improve the quality of machined surface.