Development Of Comprehensive Performance Detection System For Air Brake Valve

As executing agency for air brake system, the performance of air brakevalve directly relates to the braking system whether is normal work and its drivingsafety. At present, the domestic braking parts manufacturing enterprises still focus onthe sealing testing and testing equipment mostly depends on0.4magnitude pressuregauge shows. This leads to low degree of automation and can’t fundamentallyguarantee the reliability of test data. So it’s crucial to design a set of comprehensiveperformance detection system for Air brake valve. In this paper, a detection systemhas developed to realize test for sealing, dynamic characteristics and staticcharacteristics. The contents are as follows:Firstly, based on the analysis of air brake valve structure and working principle,this paper establishes mathematical models from quality flow, air pressure changesand force balance and analyses the performance parameters of these impact factors.According to these formulas, sets a simulation model and adopts the AMESimsoftware to carry on simulate research.Secondly, by analysis of the air brake valve’s sealing, dynamic and staticcharacteristics, designs the testing scheme accoding to QC/T35-2011and WABCOtest duidance. This system can realize testing for leakage in the braking state andnon-braking state, the response time and release time for dynamic characteristic, andinitial equilibrium pressure, predominance and maximum braking position for staticcharacteristic. In order to meet the different demands of loading rate for dynamic andstatic characteristics testing, this paper has innovative designed a set of loadingmechanism, which dynamic characteristic through the air cylinder to achieve rapidresponse while static characteristic through servo motor and ball screw to achieveuniform motion.This system is mainly consisted of industrial control computer, sensors, the dataacquisition module, dynamic and static loading mechanism, air pressure loop, testingsoftware and etc. Testing software realizes data acquisition, motion control and datamanagement, which is adopted joint programming design scheme for LabVIEW and DLL and based on the flexible design thought and multithreading technology.Thirdly, importing measurement system analysis from the six sigmamanagement systems and according to JBT10633-2006standard, this paper througha lot of testing to assess performance index of the system repeatability andreproducibility, measuring ability. Test data show that this system meet the newequipment acceptance requirements with expanded uncertainty less then8kPa，measurement ability index Cg/Cgkless than1.67, the index of discrimination largerthan6and%GagaR&R and%P/T all less than30%.At present, this system has successfully applied to the production inspection forWABCO.