拖拉机驾驶室结构噪声改进研究

Research on improvement of structural noise in tractor cabs

降低驾驶室低频结构噪声对驾驶员耳旁声压的影响。结合声学贡献量结果与正交试验法,对声学贡献量最大的结构进行改进研究。通过建立拖拉机驾驶室声固耦合模型及边界元模型进行声学响应分析并进行实验验证,针对场点声压贡献最大的结构进行改进,并通过正交试验法确定结构改进参数。结果表明,将声学贡献量法与正交试验相结合的研究方法,以驾驶员耳旁总声压为指标的改进方式,能够得到最有效降低驾驶员耳旁声压结构参数改进组合H3T3D1,右挡板施加25 mm的加强筋,右窗添加3 mm的阻尼和前挡风玻璃增厚1 mm,使该受声点总声压降低7.74 dB,并在降低原声压峰值的基础上基本没有新的声压峰值的产生。具有较好的降噪效果,研究结果可为拖拉机结构噪声控制提供参考。

To reduce the effect of low-frequency structural noise in the cab on the sound pressure near the driver’s ears, the structure with the largest acoustic contribution was improved by combining the results of the acoustic contribution and the orthogonal test method. Acoustic response analysis was carried out by establishing a tractor cab acoustic-structure coupling model and a boundary element model and verified through experiments. The structure with the largest contribution to the field point sound pressure was improved, and the structural improvement parameters were determined by the orthogonal test method. The improvement method takes the total sound pressure at the driver’s ear as the indicator. The test obtained the most effective combination of structural parameter improvement H3T3D1 for reducing the sound pressure at the driver’s ear, with the right baffle applying 25 mm reinforcing ribs, the right window adding 3 mm damping, and the front windshield thickening by 1 mm, which reduces the total sound pressure of the sound point by 7.74 dB. There is basically no new sound pressure while reducing the original sound pressure peak. The peak value has a good noise reduction effect, and the research results can provide a reference for controlling tractor structure noise.