某乘用车起步噪声分析与优化

Analysis and Optimization of Starting Noise of a Passenger Car

针对某乘用车起步噪声大问题,运用主观评价、消传递路径分析以及频谱分析技术,确定问题主要原因,在起步过程中加速结构声较大,低频存在轰鸣,加速声音和转速线性度差。提出了悬置优化、加静音钢板和标定优化方案,结果表明,悬置优化能降低低频轰鸣,但增大了2阶噪声;加静音钢板和标定优化方案皆能明显减小发动机2阶噪声,其中静音钢板方案对于低频轰鸣改善效果也较好;综合考虑建议加静音钢板和标定优化方案结合,其有利于较好的解决起步噪声大问题,提高NVH品质。

In view of the large starting noise problem of a passenger car,subjective evaluation,transmission path analysis and spectrum analysis techniques are used to determine the main cause of the problem.During the starting process,the acceleration structure is louder,there is a roar at low frequencies,and the acceleration sound and speed linearity are poor.The suspension optimization,the addition of silent steel plate and the calibration optimization scheme are proposed.The results show that the suspension optimization can reduce low-frequency roar,but increase the second-order noise;the addition of silent steel plate and the calibration optimization scheme can significantly reduce the engine’s second-order noise.Among them,the silent steel plate solution is also better for improving the low-frequency roar;comprehensive consideration is to combine the silent steel plate with the calibration optimization solution,which is conducive to better solving the problem of large initial noise and improving the quality of NVH.