基于生命周期的数控车床寿命分布模型及控制

针对国产数控机床故障频繁的问题,提出了建立基于生命周期的寿命分布模型,并揭示了故障机理和规律.选择国产和进口相同类型的数控车床,由同一机床用户进行现场跟踪试验.通过对故障时间信息进行拟合优度检验等建模分析,得出两类寿命分布模型:发达国家机床运行于故障率近似恒定的偶然故障期;而国产机床寿命模型包含浴盆曲线左侧面,首先运行于高故障率的早期故障期,然后过渡到偶然故障期.由此揭示了造成国内外机床可靠性差距的原因,提出了消除早期故障的方法,采用该方法可显著提高国产机床的可靠性水平.

Lifetime Distribution Model and Control for CNC Lathes Based on Life Cycle

The homemade CNC machine tools fail frequently whilst running. The lifetime distribution models based on life cycle of CNC machine tools were proposed to reveal the failure mechanism and rule. The field tracing test for the same type of homemade and import CNC lathes was carried out. After analyzing the fault data of time between failure by curves fitting and hypothesis test, two kinds of lifetime distribution models were found, which indicate those products from developed countries running on random failure period in where their failure rate is almost constant, those from home factories running on early failure period at first in where their failure rate is higher, and then transiting into random failure period. It is why the reliability level of homemade CNC machine tools is lower. The approaches to remove the early failure of those products were presented, with which reliability level of homemade CNC machine tools was obviously enhanced.