收割机用柴油机输出端异响分析与设计优化

Abnormal noise analysis and optimal design of diesel engine output for harvester

采用频谱分析、模态仿真与测试对某收割机用轻型柴油机离合器分离时各转速下存在的异响进行分析,确定噪声异响源为离合器外齿圈撞击柴油机飞轮内齿圈引起飞轮结构共振产生的表面辐射噪声。从噪声激励源、传递路径以及结构响应3方面进行系统分析,采取优化柴油机燃烧激励、增大飞轮刚度降低结构响应、增厚挡板并加密封吸音棉等改进措施。试验表明改进方案降噪效果非常明显。

The abnormal noise of a light diesel engine clutch used in a harvester at different speeds is analyzed by means of spectrum analysis, modal simulation and testing. The reason of abnormal noise is ascertained that the outer gear ring of clutch hints the inner gear ring of the flywheel of engine, which cause the resonance of the flywheel structure. On this basis, the noise excitation source, transfer path and structural response are systematically analyzed. Some improvement measures are taken, such as combustion optimization, increasing flywheel stiffness to reduce structural response, thickening baffle and adding sealed sound-absorbing cotton. The experimental results show that the improved scheme is very effective in noise reduction.