Development Of Testboard For Performance Of Automatic Slack Adjuster

As a key component of braking system, the performance of automaticslack adjuster relates to the braking system whether is normal work and drivingsafety. At present, domestic does not have the test equipment of automatic slackadjuster, it can only provide relevant simple performance testing, there are greatshortcomings in testing method, precision, reliability and automaticity of theequipment; meanwhile, foreign advanced testing equipment, testing technology andspecific detection are all blockaded to our country, we can not reference. Therefore,it is crucial to design a set of performance detection system for ensuring the qualityof automatic slack adjuster. The detection system can realize the tests forautomodulation, free travel, torque modulation and static strength.In this paper, the main content includes the following aspects:Firstly, the paper introduces the structure, working principle and characteristicsof automatic slack adjuster, then analyze the performance index and primary testingobjectives.Secondly, based on the United States SAE J1462-1994standard and thedomestic existing industry standard, the design decision of performance testingsystem of automatic slack adjuster is formulated. The system realizes to test someparameters such as shell stroke, worm corner and brake clearance in the brakingprocess of automatic slack adjuster, load torque and automatic clearance in the test offree travel, torque modulation and worm corner in the test of torque modulation, loadforce in the static strength test. Then both the hardware platform and software aredesigned and realized based on industry control computer. The hardware platform ismade up of industry control computer, sensor, data acquisition module, motioncontrol agency, gas supply system and so on. Using Visual C++6.0programming,the testing software realizes the functions of data acquisition, motion control and datamanagement and so on.Thirdly, using the testboard for performance of automatic slack adjuster, the paper detects automodulation, free travel, torque modulation and static strength, thenjudge the performance of the automatic slack adjuster whether it is qualified throughthe analysis of the testing curve and data. According to the standard JBT10633-2006"the guide for special testing equipment evaluation method ", this paper evaluates theperformance index of the system repeatability, reproducibility and measuring ability.The testing data shows that the measurement ability index C_g/C_gk greater than2.0,they meet the requirements of the new equipment acceptance.