Abstract: The gasoline direct injection system fault tree was estab!ished combining with the experience of automobile fault diagnosis expert. The minimal cut sets of 4 essential fault models were analyzed , and then a three-level structure model was established. The weight of each basic event OCCUlTence probability in the fault tree was obtained by analytic hierarchy process , and the weak link of the system reliability was found out by so此ing. The reliability of the high importance components including fuel pump , fuel injector, high pressure fuel pump , and fuel pump control unit were analyzed. Useful recommendations for system optimization and maintenance are proposed and the efficiency of fault diagnosis is improved.

Key words: vehicle engineering, engines, gasoline direct injection, reliability analysis

摘要： 结合汽车故障诊断专家经验，构建了汽油直接喷射系统失效的故障树，分析了4种主要故障形式的最小割集， 依此建立层次模型。利用层次分析法，定量计算出系统各底层事件发生概率的权值，通过排序找出影响系统可靠性 的薄弱环节。对燃油泵、喷油器、高压油泵与油压调节器、燃油泵控制单元、进气翻板位置传感器等高重要度部件进 行可靠性分析，为系统优化改进、使用维护、故障诊断的效率提升提出建议。

关键词: 车辆工程, 发动机, 汽油直接喷射, 可靠性分析