Abstract: In this paper, the vibration of the overhead guard of a forklift is diagnosed. Firstly, the vibration signals are collected when the forklift is operating, and the signals corresponding to the worst subjective evaluation of comfort are extracted and analyzed. Then, the modal test of the overhead guard of the forklift is conducted, and the results are compared with the vibration signals corresponding to the worst comfort. It is found that the main reason of the forklift vibration which leads to the worst comfort is the resonance of the overhead guard excited by the engine. Since the modals of the overhead guard structure in the vicinity of the resonance frequency are very close one another, successive resonance will occur in the acceleration period, which is a serious impact on the comfort of the forklift. Finally, a scheme for reducing the vibration is proposed. A correlation between objective measurements and subjective evaluation is found by means of the proposed approach. This work supplies references for the vibration isolation design.

Key words: vibration and wave, forklift, modal testingm, vibration isolation

摘要： 针对某型号叉车护顶架、方向盘和座位振动较大的问题，首先对该型号叉车运行时的振动信号进行了采集，找出主观舒适度最差时刻的信号并侧重其进行分析。通过对护顶架做模态测试，将所测试的模态参数与现场主观振动评估结果相结合，确定导致该型号叉车舒适度较差的主要原因是护顶架在发动机激励下产生共振，且由于在共振频率周围护顶架结构模态较为密集，导致叉车加速状态下会产生连续的共振。由于在模态测试基础上引入了舒适度评估振动的方式，结果表明具有今后改进设计的价值。

关键词: 振动与波, 叉车, 模态测试, 隔振