Abstract:

Through analyzing the working principle of automatic brake adjuster,this paper used FTA  method to establish a
mathematic failure model of helical compression spring,which directly caused the disable of automatic brake adjuster's self-regulation.Both of  the model
and the data of separation force and backlash which were tested by a measurement system of automatic brake adjuster,were used to judge whether the
critical position of the function of automatic brake adjuster's self-regulation was failure.As well,through testing the value change of adjusted torque to check whether the failure model above was right.Through the experiments,this model can judge correctly whether the function of automatic brake adjuster's self-regulation is failure.

Key words: automatic brake adjuster, self-regulation, helical compression spring, failure model, fault tree analysis(FTA) method

摘要：

通过分析自动调整臂的工作原理,基于故障树分析法（FTA）构建了引起自动调整臂自调功能失效的螺旋压缩弹簧的失效模型。结合该模型,利用自动调整臂综合性能测试系统测得的分离力和分离间隙数据来判断自调功能发生失效的临界点,通过测试调整力矩值的变化对上述模型加以验证。实验验证结果表明,该模型能正确判别自动调整臂的自调功能是否发生失效。

关键词: 自动调整臂, 自调功能, 螺旋压缩弹簧, 失效模型, 故障树分析法