针对某型号履带式液压挖掘机驾驶室怠速时声振舒适性较差的问题，对其进行测试并分析发动机、驾驶室两级悬置的隔振性能及上车架的振动，确定怠速时上车架受发动机激励产生共振。对上车架结构进行改进，并通过有限元模态分析预测了改进效果。试制样件后再次测试，发现驾驶室内噪声明显下降，上车架的低频共振基本消除。以怠速时驾驶员右耳耳旁噪声的响度、粗糙度和抖动度为指标，对驾驶室的声振舒适性进行了客观评价。结果表明，上车架改进后的各参数较改进前均有所下降，驾驶室的声振舒适性得到改善。%The vibration isolation performance of the suspension system of an excavator which supports the engine and the cab, and the vibration of the upper frame, are analyzed based on the test results. It is found that a low-frequency resonance excited by the engine occurs in the upper frame. The structure of the upper frame is modified, and the validity of the modification is predicted by modal analysis simulation and is verified by the tests. The NVH character of the cab is estimated by the parameters of loudness, roughness and fluctuation intensity corresponding to the noise at the driver’s right ear. It is shown that these parameters are reduced apparently after the modification of the upper frame and the NVH character of the cab is improved.
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