基于发动机悬置动刚度分析的车内降噪研究

某微型客车在行驶过程中发动机高转速时驾驶室产生共鸣声,车身有严重的振动现象。NVH测试结果显示发动机右悬置支架Z向动刚度偏低。采用有限元分析方法对发动机右悬置进行动刚度分析,基于动力总成悬置系统刚度匹配原则和结构参数敏感性分析,并考虑装配及焊接工艺等因素,提出一个较为合理的改进方案。改进方案装车后NVH测试结果表明车内噪声明显降低,发动机转速为3 315 r/min时降了4.3 dB,3 671 r/min时降了10 dB,3 860r/min时降了4.5 dB,车身振动主观感觉亦有明显减弱。

Research on Reducing Interior Noise Based on the Analysis of Engine Mounting Dynamic Stiffness

There are obviously booming noise inside a small passenger vehicle during driving in high engine speeds.It also go with strong resonance phenomena of the body. The test result shows that the dynamic stiffness in Z direction of the right engine mount is low. In this paper,a finite element method was used for the analysis of the dynamic stiffness of the engine mount structure. Based on the match principle of the powertrain mounting system, using structural parameter sensitivity analysis technique, with considering the assembly and welding factors, a reasonable optimized case was proposed. Refixing one existing small passenger vehicle with the proposed case. The test result in steady state condition shows that interior noise significantly reduced.h reduced 4.3dB around engine speed 3 315 r/min, 10dB around engine speed 3 671 r/min ,4.5dB around engine speed 3 860 r/min, and the resonance phenomena of the body become obviously weak.