基于动刚度分析优化的汽车怠速噪声控制

Control of the Vehicle Idle Speeding Noise Based on Dynamic Stiffness Analysis and Optimization

针对某轿车在怠速时驾驶舱内出现“呜呜”声,经测试排查,主要由排气系统激励引起,仿真分析该频率下挂钩与车身安装点动刚度不足,排气系统激励传递到车身上引起振动,产生车内低频噪音。采用ODS分析优化方法,改进排气吊钩结构,排气吊钩动刚度在181 Hz频率由385 N/mm提高到1340 N/mm。实测对比结果表明,搭载新结构的排气吊钩后,在怠速183 Hz时驾驶舱内噪声声压级下降8 dB且“呜呜”声消失,与主观评价一致。新的吊钩解决了怠速噪声问题,验证了该方法的有效性。

xConsidering the Idle speeding problem of a car,by test analysis,It is mainly caused by exhaust system excitation.By simulation analysis of this frequency,the dynamic stiffness of the connection between exhaust hook and body installation point is insufficient.Exhaust system excitation is transmitted to the car body to cause vibration,resulting in low frequency noise inside the car.Though modal analysis and ods optimization,dynamic stiffness of the Exhaust hook was raised from 385 to 1340.Test results indicate that the noise is reduced by 8dB and low frequency noise was disappeared by using new structure of the exhaust hook,as the same with the subjection evaluation.The improved exhaust hook can reduce the Idle speeding noise problem of a car,showing the effectiveness of this method.