数控机床进给系统精度保持性研究

Study on Accuracy Stability Testing of Servo Feed System on CNC Machine Tool

设计了机床进给系统的精度保持性试验,对其试验方法进行了研究;在整个寿命期的精度数据分析过程中,运用基于AMSAA模型的非齐次泊松过程理论,对定位精度随累积跑合行程的变化规律及其分布函数进行了拟合。结果表明:在跑和初期,进给系统处于磨合期,随着跑合次数的增加失效率逐渐降低;当跑合次数超过300次后,失效率趋于稳定,进给系统进入稳定期;实现了精度保持性与可靠性理论的结合,并验证了定位精度预测公式的可靠性。

A test was designed, which concerns to the precision retaining ability of machine tool＇s feed system, and the test meth- od was also researched. The changing pattern and distribution function of positioning accuracy with accumulated distance was fitted, in the process of analyzing the accuracy data of the hole life cycle, by using the nonhomogeneous position process theory based on AMSAA model. The results indicate that during the initial period, the feed system is in the process of running-in, with the increase of running- in times gradually the failure rate reduces. After the running-in time beyond 300, the failure rate becomes stable, the feed system is in stable period. The combination of accuracy retaining and reliability theory is realized, and the reliability of the positioning accuracy prediction formula is verified.