某乘用车加速工况车内轰鸣声诊断分析及控制方法

Diagnosis analysis and control method of booming noise in car’s passenger

该文针对某乘用车加速工况出现的轰鸣声进行诊断分析与控制。首先通过主观评价确定问题工况,通过实车测试发现2400 r/min左右车内存在明显轰鸣声。利用阶次分析、模态分析及错频验证可知,发动机激励经悬置传递副车架,引起副车架的共振,进而传递到车内引起轰鸣声。最后通过传递分析及柔性连接点导纳法,优化副车架橡胶衬套结构。结果表明,优化后在2400 r/min声压总级与2阶声压差值为7.5 dB(A);声压总级较原状态降低2 dB(A),2阶噪声降低7.8 dB(A),声压总级和2阶噪声声压差值增大,轰鸣声明显减小,主观评价可接受。

In this paper,diagnosis,analysis and control of the roar of a passenger car under acceleration conditions are carried out.First of all,the problem conditions are determined through subjective evaluation,and through the real vehicle test,it is found that there is obvious roaring noise in the car around 2400 r/min.Using order analysis,modal analysis and frequency-staggered verification,it can be seen that the engine excitation is transmitted to the sub-frame through the suspension,causing the resonance of the sub-frame,which is then transmitted to the interior of the vehicle to cause a roaring sound.Finally,the subframe rubber bushing structure is optimized by transfer analysis andflexible connection point admittance method.The results show that after optimization,the difference between the overall level at 2400 r/min and the second-order sound pressure is 7.5 dB(A);The overall level and the second order noise sound pressure increase,and the roaring sound decreases significantly.The subjective evaluation is acceptable.