Development And Implementation Of High Temperature Performance Testing System For Muffler

As the most effective key component to suppress the motor vehicle exhaust noise,the forward design and performance testing of muffler are the key technical problems of the automobile and motorcycle industry in our country.Transmission loss is the core performance index of muffler,which measures noise reduction effect of muffler,and has important influence on product overall comfort.In addition,the thermal durability of mufflers is one of the concerns in the whole life cycle of its products,and also has a great impact on product quality evaluation.Traditional performance test of muffler is tested under the condition of normal temperature and no air flow,especially in the process of transmission loss test,which does not reflect the influence of the muffler through the actual working conditions of high temperature and high speed airflow,so it can not accurately reflect the actual performance of the muffler.In view of this,this paper designed and developed a set of high temperature muffler performance testing system,which aims to improve the ability of the muffler test bench to simulate the actual working condition and the degree of automation,so that accurate and effective test results of muffler can be obtained quickly.The transmission loss of mufflers is the difference between the level of the incoming sound power at the entrance of muffler and the sound power level at the outlet.In the first chapter,after comparing various testing methods and referring to the research situation at home and abroad,we use four microphone method to measure muffler transmission loss.The second chapter briefly describes the theoretical knowledge of the four microphone method,and puts forward the overall scheme of the high temperature muffler performance testing system based on the testing principle.The overall scheme includes hardware structure,process control system based on PLC and software system based on Labview.The third chapter introduces the design of the hardware structure of the muffler test system,including the hardware of the blast system,the hardware of the heating system,the hardware of the acoustic system,the tail gas treatment device,the support and the design of the thermal insulation / heat dissipation device.The fourth chapter introduces the development and implementation of process control system based on PLC in detail.The fifth chapter carries out a detailed requirement analysis to the software system,and implements the whole software system function based on Labview,including manmachine interaction,state monitoring,test measurement,data analysis,report generation,user management and so on.Finally,the transmission loss experiments of mufflers under various conditions are carried out,and compared with the test results of the existing test stations and the software simulation results.Experimental results show that the test system achieves high temperature environment simulation and transmission loss test.The test system plays a positive role in improving the positive design ability of mufflers and ensuring the reliability of mufflers at high temperature and high pressure,and also improves the performance of our automobile and motorcycle enterprises and make them more competitive.