基于FTA-FMMEA综合分析法的发动机曲柄连杆机构可靠性研究

Research on the Reliability of the Engine Crank Rod System Based on FTA-FMMEA Comprehensive Analysis

为了提高发动机曲柄连杆机构的可靠度,采用FTA-FMMEA综合分析法对其进行分析。通过分析曲柄连杆机构各零件的故障,建立故障树模型,对其进行定性分析找出对系统影响较大的故障模式;对其中的活塞环磨损这一故障模式进行FMMEA分析,得到了其故障原因及故障机理,确定了其故障影响,并根据分析结果提出改进方案。改进前后的RPN值对比结果表明,FTA-FMMEA综合分析方法可以很好的分析系统故障并提高系统可靠性水平。

FTA-FMMEA comprehensive analysis method can be used to improve the reliability of engine crank rod system.The analysis process can be described as follows： firstly,establish the fault tree model based on the analysis of the part failures of the crank rod system,and find the hazardous failure mode according to FTA qualitative analysis;then analyze the mode ＂scuffing＂ of the piston ring by using FMMEA,get the failure cause and failure mechanism,find the failure effect,and finally give the correction measures according to the analytical results.The comparison result of RPN value before and after correction indicated that FTA-FMMEA comprehensive analysis can effectively analyze system failures and improve the system reliability.