Noise Analysis And Technology Improvement For Sunroof

With the continuous development of the country,the automobile industry in China has developed rapidly,and the volume of automobile production and the amount of ownership have leaped into the first place in the world.In recent years,people's economic living standard has been obviously improved.More and more cars have come into the ordinary family.At the same time,people have higher requirements for the comfort performance from a sedan.The sedan as the main vehicle for the people in our lives to bring a huge change,but the disadvantage is also constantly expanding,the noise is often happen from a sedan,Especially the wind vibration noise problem for a sedan,so we must have a further improvement for some parts.This article is focused on the noise problem of sunroof for E302 sedan with three compartment produced by Benz company.Through do simulation analysis and road test to improve winddeflector.This paper firstly elaborates the domestic and international development trend for sedan sunroof.The practical value is based on the research of winddeflector noise problem for E302 sedan sunroof.One road of solving problem is clear from find the problem.Analyze the problem to the implementation of short solution,at last do the prototype sample to test,and make continuous reasoning and inquiry to solve the noise problem.The wind vibration noise principle for winddeflector is studied in this paper.It is preliminarily determined that the noise comes from the deformation of winddeflector frame or the large gap between the winddeflector frame and the front frame of sunroof.Calculating the stiffness by Hypermesh and Abaqus software,the factors of the deformation for winddeflector is eliminated.The problem of the excessive gap between the two parts is analyzed and verified by increasing the felt of different lengths.It is determined that the noise can be improved by reducing the gap between two parts according to the verification results.Then the proposed change scheme is simulated by CFD,and the ideal part state is determined from the vorticity cloud image.According to the simulation results,the frame structure under winddeflector is improved.The prototype sample is made and verified by wind tunnel test,high ring road test and so on,confirm that the improved sample meets the requirements.Finally,the improved winddeflector has been successfully applied to the batch production of E302 sedan.