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

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