真空泵系统引致车内结构噪声快速识别与控制

Rapid Identification and Control of Interior Structural Noise Caused by Vacuum Pump System

针对某车辆怠速工况下多次深踩制动踏板后驾驶室内出现“哒哒”声异响问题,采用小波分析方法快速识别出异响源为真空泵系统,对真空泵系统进行全面分析,确认异响原因为:采用真空泵抽真空时气流产生压力脉动冲击,该冲击经过“真空泵-管路-固定支架-前围板”结构路径产生异响传递至驾驶室。根据异响机理,提出4种优化方案:(1)噪声源优化;(2)结构路径隔离;(3)路径低刚度隔振;(4)路径高阻尼衰减;详细介绍和对比分析4种方法的优缺点,对于应用于工程实际的短期方案和长期方案给出建议,通过分析测试数据可知,采用这4种方案可将原状态异常振动峰值从0.69 g分别降低至0.23 g、0.15 g(无异常峰值)、0.42 g、0.38 g,优化效果明显。

Aiming at the problem of abnormal noise in the cab of a vehicle after repeatedly stepping on the brake pedal in idling condition,the wavelet analysis method is used to quickly identify that the vacuum pump system is the abnormal noise source.Then,the vacuum pump system is analyzed carefully.It is confirmed that when the vacuum pump is operating,the air flow produces pressure pulsation and impact,which is transmitted to the cab as the abnormal noise through the structural path of"vacuum pump-pipeline-fixed bracket-body front panel".According to the abnormal noise mechanism,four solution schemes,such as optimizing the noise source,structural path isolation,low stiffness vibration isolation and high damping attenuation of the path,for optimizing the problem are proposed.The advantages and disadvantages of the four schemes are discussed and compared in detail,and the suggestions for short-term and long-term schemes in engineering practice are given.According to the test data analysis,the abnormal vibration peak value of the original state is reduced from 0.69 g to 0.23 g,0.15 g(no abnormal peak),0.42 g and 0.38 g respectively by the four schemes,and the optimization effect is obvious.