Study On The Analysis And Control Technology For The Pass-by Noise Of Mini-vehicle

The major component of urban traffic noise,vehicle noise,have a serious impact on the urban environment,on people's lives,work causing distress.Therefore,in the current automotive industry,both in vehicle noise control methods,with emphasis on controlling the vehicle acceleration noise.For vehicle acceleration noise,after its generation mechanism,transmission analysis and summary,to mini-vehicle for the study,analysis of the status of its radiation outside the vehicle acceleration noise for noise source identification,take spectrum analysis,sound intensity measurement for the main part of the car,the noise generated by the size of the preliminary determination,as well as throughout the vehicle acceleration noise occupy proportion.The results showed that the largest proportion,that is the main source of noise is the exhaust noise,engine noise radiation.For radiated noise produced by the engine,in order to further identify students,by means of surface vibration method,sound intensity measurement technique,the results that the main source of radiation transmitter noise is a cylinder head cover,exhaust manifold cover,oil pan shell,they radiate a lot of noise energy.Referring to the results of the identification of the sound source,targeted to develop appropriate programs to control the noise.Since the exhaust muffler research vehicle has a very large flow noise,high-frequency noise,for the redesign and improvement of the muffler,the test results show that the design improves performance muffler,amplitude 3~5dB(A).Can be used to control noise damping,sound insulation and sound absorption,the present design of the integrated use of these methods to select targeted materials for the implementation of noise oil pan,hood and engine compartment,the radiation noise produced by the engine is reduced and control.Before designing,after the implementation of noise control programs,mini-car noise control obtained more satisfactory results,the implementation of the control scheme,the value of 75.5dB(A),and after the implementation of the program,the value drops to 73.7dB(A),noise value meets the requirements of GBl495-2002.