制动气室推杆行程故障诊断

推杆行程失调会引起客车制动力的损失，使制动力矩减小，针对此问题提出了一种诊断制动气室推杆行程失调故障的方法。分析了气制动系统中的制动总阀和制动气室的工作状态，利用模型对制动气室伸出推杆的行程值进行理论估计，通过判断估计值是否落在规定的推杆有效行程范围内，对系统是否存在推杆行程失调故障进行判断。然后搭建了整车气压制动系统模拟试验台，针对整车制动系统进行制动性能模拟试验，对制动气室的气压变化量进行测量，将归一化后的试验值与理论值进行比较，对气制动系统是否存在推杆行程失调进行了诊断。试验结果表明，该模型能很好地对气制动系统推杆行程失调进行故障诊断。

Push Rod Stroke Fault Diagnosis for Air Brake Systems

 In the car air brake system the imbalance of the push rod stroke can cause the loss of breaking force and the decrease of breaking torque. Aimed at this problem a model based imbalance of the push rod stroke fault diagnostic method for the brake chamber is presented. First, the working condition of the brake valve and the brake chamber in the air brake system is analyzed. The push rod stroke value according to the model is estimated. The estimated push rod stroke is detected whether within the effective range to judging the imbalance fault. A simulation test rig for the vehicle air brake system is built to simulate the braking performance. The brake performance by this simulative test rig can be gotten and the brake chamber state pressure can be measured. The normalized data measured in experiments are compared with the predictions of the model. So it can diagnose the imbalance of the push rod stroke fault. Test results show that the method is effective to diagnose the imbalance of the push rod stroke fault for air brakes.