基于失效模式的曲轴再制造工艺优化方法研究

Remanufacturing process optimization method for crankshaft based on failure modes

针对曲轴再制造过程中工艺路线复杂多样的问题,从曲轴的工作状况、材料选择、失效原因和损伤程度等方面进行了研究,提出了基于失效模式的曲轴再制造工艺优化方法。通过故障树分析法分析了曲轴失效的主要原因,用树形图表示出来,从中提取了影响再制造工艺的关键因素作为失效特征;基于实际工作经验给出了失效特征的量化标准,并将量化结果作为选取再制造工艺的主要条件;根据再制造工艺标准剔除了不合理的工艺路线,并将结果用与或图简明表示出来,建立了涵盖经济成本与时间成本的再制造成本函数,对结果数据进行了无量纲化处理,分析比较了简化后的工艺路线,选取了成本最低的路线作为最优再制造工艺路线;选取DB-7020帕萨特汽车废旧曲轴为目标,从磨损、裂纹和变形失效角度进行了分析,应用再制造工艺优化方法获得了可行的再制造工艺路线,并通过再制造成本函数评价得到了最优路线。研究结果表明:再制造工艺优化方法可以解决由于废旧曲轴失效形式和失效程度不同而导致的工艺复杂性问题,能够提高再制造工艺选择的合理性和再制造效率。

Aiming at the problem that the process routes are complicated and diversified in crankshaft remanufacturing the crankshaft working con ditions material selection failure causes and damage degree were studied and a remanufacturing process optimization method for crankshaft based on failure modes was presented. The main causes of crankshaft failure were analyzed by fault tree analysis method and expressed by tree diagram. Futhermore the key factors affecting remanufacturing process were extracted as failure characteristics. The quantitative criteria of failure character istics for crankshaft were proposed based on engineering experience in practical work and the quantified results were taken as the main conditions for selecting remanufacturing process. The unreasonable process routes were removed by remanufacturing process standards and the result was ex pressed as AND/ OR diagrams. Remanufacturing cost function including economic and time costs was established. And the evaluation results were processed by dimensionless method. The simplified routes were analyzed and compared the lowest cost route was selected as the optimal route of remanufacturing process. The point of wear crack and deformation failure of DB 7020 Passat automobile crankshaft was analyzed. Remanufacturing process routes were obtained by applying remanufacturing process optimization method and the optimal route was obtained by remanufacturing cost function. The results indicate that the problem of process complexity caused by different failure forms and degrees of used crankshaft can be solved by remanufacturing process optimization method. And the rationality of process selection and remanufacturing efficiency can be improved.