4LL–1.5Y型联合收割机割台的振动特性

Analysis on vibration characteristics of the header for 4LL–1.5Y combined harvester

运用有限元软件ANSYS workbench仿真分析4LL–1.5Y型联合收割机割台,得到割台机架前6阶模态频率和模态振型,结果表明,割台在受振动时易产生变形的部位是割台机架的两侧壁和割台机架进口处的底板。利用三轴加速度传感和Co Co–80动态信号测试分析系统,分别测得割台机架关键部位的加速度信号,对比非田间作业试验发动机空转、整机运转(不行走)分别在怠速(700 r/min)、中速(1 200 r/min)、高速(1 800 r/min)和田间作业不同工况下各方向的加速度,各测点水平方向加速度是其他2方向的2~4倍,表明割台的振动主要以水平方向振动为主,其中倾斜输送器受振动比较严重,加速度最大值高达97.28 m/s2。对比有限元分析与振动试验结果发现,对割台振动影响较大的激励频率(20、22 Hz)几乎都出现在割台机架的模态频率(18.679 Hz)附近。

The vibration of the header for 4 LL–1.5 Y combined harvester has been studied by the ANSYS workbench simulation and the vibration experiment. The model frequencies and shapes of the header frame were obtained by the simulation in ANSYS workbench. The results showed that the two sides and the entrance floor of the header frame deformed easily while the combine harvester vibrating. Using the triaxial acceleration instrument and the Co Co–80 dynamic signal analysis system, the acceleration signals of the important parts of the header frame were measured separately, and the vibrations under different working conditions, like low speed（700 r/min）, middle speed（1 200 r/min）, high speed（1 800 r/min）, were tested in the experiment field. The data showed that the acceleration in the horizontal direction as 2–4 times as that the other two directions, and the vibration mainly occurred in the horizontal direction. Additionally, the vibration of the leaning transporter was very serious, with the high value of 97.28 m/s2. Compared the results of the ANSYS workbench simulation with the experiments, the excitation frequency of 20 Hz and 22 Hz, which had great impact on the vibration of the header, mainly appear near the model frequency of 18.679 Hz for the header frame.