摘要
针对果园垄面割草机作业时振动剧烈从而导致割茬高度稳定性差、机械寿命短、作业效率低等问题,通过运用ANSYS Workbench软件对垄面切割装置进行基础模态分析和振动动力学分析。在模态分析的基础上针对切割装置各关键特征节点的振动位移进行响应分析,从而探究其工作状态下激振频率对切割装置各特征节点加速度载荷值的影响。对比分析结果表明切割装置1阶模态频率对应的极限转速远低于其危险转速范围;经过加速度载荷值数据的比对,得出工作状态下的Z向主要振动传递路径;对切割装置进行谐响应分析,得出在180 Hz时甩刀顶端的径向振幅达到最大值,为12.3 mm;在250 Hz时,花键套与刀盘连接处的径向振幅达到峰值,为7.7 mm;通过田间试验得出平均切割高度偏移最大值为28 mm,与切割装置的一阶振动偏移量32.43 mm接近,数据可靠;改进后田间试验数据显示平均割茬高度与设定高度最大差值为10 mm,有效的保证了割茬高度的稳定性。通过振动分析和田间试验表明,在作业前将拖拉机提前启动并维持稳定动力输出进行作业可有效避开切割装置自身的共振频率,采用更换加厚甩刀和在花键套与主轴的连接处加设橡胶垫圈的方法,可降低切割装置的振动,保证割茬高度的稳定,研究结果可为果园割草机垄面切割装置减振措施的研究提供数据基础和新思路。
Aiming at the severe vibration of the orchard ridge mower during operation,which results in poor stubble height stability,short mechanical life,and low work efficiency,the basic modal analysis and vibration dynamics analysis of the ridge cutting device are carried out by using ANSYS Workbench software.Based on the modal analysis,the response analysis of the vibration displacement of each key characteristic node of the cutting device is carried out,so as to explore the influence of the excitation frequency on the acceleration load value of each characteristic node of the cutting device in its working state.The comparative analysis results show that the limiting speed corresponding to the first-order modal frequency of the cutting device is much lower than its dangerous speed range;after the comparison of acceleration load value data,the Z-direction main vibration transmission path under working conditions is obtained.Response analysis shows that at 180 Hz,the radial amplitude of the tip of the flail reaches the maximum value of 12.3 mm.At 250 Hz,the radial amplitude of the joint between the spline sleeve and the cutter head reaches the peak value of 7.7 mm.The test shows that the maximum deviation of the average cutting height is 28 mm,which is close to the first-order vibration deviation of the cutting device 32.43 mm,and the data is reliable;the improved field test data shows that the maximum difference between the average cutting height and the set height is 10 mm,which is effective This ensures the stability of the cutting stubble height.Vibration analysis and field tests show that starting the tractor in advance and maintaining a stable power output before operation can effectively avoid the resonance frequency of the cutting device itself.It adopts the replacement of thick flail and the connection between the spline sleeve and the main shaft.The method of installing rubber gaskets can reduce the vibration of the cutting device and ensure the stability of the cutting height.The research results can provide a
作者
李雪军
毛雷
杨欣
王鹏飞
刘洪杰
李建平
Li Xuejun;Mao Lei;Yang Xin;Wang Pengfei;Liu Hongjie;Li Jianping(School of Mechanical and Electrical Engineering,Hebei Agricultural University,Baoding,071000,China)
出处
《中国农机化学报》
北大核心
2020年第11期51-59,共9页
Journal of Chinese Agricultural Mechanization
基金
河北省重点研发计划项目(19221902D)
河北省现代农业产业技术体系水果创新团队(HBCT2018100205)
国家现代农业产业技术体系专项资金(CARS—27)。
