工程机械动力舱罩的隔声性能分析

Analysis of Sound Insulation Performance of a Power System Enclosure for Construction Machinery

面向工程机械动力舱罩“散热-降噪”平衡的需求,设计一种新型的动力舱罩双层周期结构,并结合某型双钢轮振动压路机的整机噪声特性研究,应用有限单元法对新型动力舱罩的声传递损失进行分析。结果表明,在目标频段内,改进的动力舱罩在不降低动力系统通风散热性能前提下表现出良好隔声性能。最后通过“混响室-消声室”法及实车测试测量动力舱罩改进结构和具有相同开孔面积的单层板传递损失,验证了改进动力舱罩双层周期结构对提高隔声薄弱频段内声传递损失的有效性。

In order to balance the requirement between ventilation and noise reduction of the power system enclosure of engineering machinery,a new double-layer periodic power system enclosure is proposed.By using finite element method and targeting noise level reduction of a double-wheel vibratory roller,the sound transmission loss of the proposed structure is analyzed.The results show that the new power system enclosure presents a good sound insulation performance in the targeted frequency regions without decreasing the heat dissipation capability.Finally,the sound transmission losses of the proposed structure and a single-layer plate with the same ventilation area are measured by reverberation-anechoic chamber method to verify the improvement effect on sound insulation performance.The noise level of the vibratory roller is also measured in the cases before and after installing the proposed enclosure to further testify its noise-reduction effectiveness.It is verified that the improved power system enclosure with double-layer periodic structure can effectively raise the sound transmission loss in the weak-isolation frequency range.