基于精密装配和双驱优化的数控机床定位问题分析与处理

Analysis and Treatment of NC Machine Tool Positioning Problem Based on Precise Assembly and Dual-driving Optimization

某型数控机床的一个摆动轴在失去重力平衡后,出现"定位异常"问题。作者在没有更换主要传动部件的情况下,提出了降低该问题的影响程度的方法。针对某大型五轴龙门数控机床的一个双驱摆动轴在急停报警后出现的定位异常偏摆问题,应用排除法得出了机械传动链存在间隙或打滑现象是其主要原因。结合工厂生产实际和备件等待周期,通过对旧传动部件的精密装配减少了偏摆量;对蜗轮蜗杆双驱传动进行了同步和优化,延长精密装配部件的使用寿命;通过延长液压平衡对重力补偿的持续时间,弥补了精密装配无法消除的旧件磨损误差,最终降低了问题的影响程度。经过连续11个月的使用,尽管期间出现急停报警6次,但无一次工件铣伤问题,验证了以上方法的有效性。在不更换旧传动部件的情况下,通过精密装配恢复了机床的功能,通过液压平衡弥补了旧件带来的误差,在机床应用和维修中具有较强的实用价值。

The "Positioning abnormality" situation, that a wing shafts of gantry Numerical Control(NC) machine tools losing the gravity balance, has been reduced efficiently without replacing the main drive parts, for this a method is proposed. The mechanical transmission gap and slipping were the main reason according to exclusive analysis, for the wing shaft precision abnormality after emergency stop alarmed from a dual-driving wing shaft of one large type 5-axis gantry NC machine tool. Base on the practical production and the waiting period of spare parts in one plant, the old component’s deflection was reduced through the precise assembly, and the dual drive parts transmission was optimized and synchronized to prolong the service life. Also the hydraulic balance time to gravitational compensation had been prolonged to make up for the wears error of used parts which were hard to eliminate in precise assembly, and finally reduced largely the influence of the problem to machine tools. There was no part accident happened, although 6 times emergency stop alarm occurred during 11 months continuously using, which proved the effectiveness above method. Machine’s function is recovered without replacing the traditional transmission old parts, and the old errors are compensated using hydraulic balance, which has strong practical value in using and maintenance.