联合收获机切割器驱动装置减振设计与试验  

Design and test on vibration reduction for knife driving device of combine harvester

作　　者：王志明[1,2] 马广[2] 吕彭民[1] 陈霓[2] 

机构地区：[1]长安大学道路施工技术与装备教育部重点实验室,西安710064 [2]金华职业技术学院机电工程学院,浙江金华321017

出　　处：《浙江大学学报（农业与生命科学版）》2014年第5期579-584,共6页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家自然科学基金资助项目(51305182)

摘　　要：为提高联合收获机割台的工作可靠性,构建了联合收获机切割器驱动装置力学模型,对平衡块安装位置和质量2个减振参数进行了理论计算.当曲柄轴转速为常用转速700 r/min时,计算得到最佳减振设计参数组合为平衡块质量1.677 kg,平衡块安装位置243°.在4LZS-1.8型联合收获机割台上进行振动试验,对滤波处理后的振动加速度测量值和惯性力计算值进行时间序列分析比较,验证了力学模型的准确性;最佳减振设计参数组合的减振比为66.3%,切割器驱动装置摇臂末端与切割器连接处的间隙是造成割台非线性振动的主要原因.为了明确由于长期使用导致间隙扩大造成振动加剧对减振设计参数的影响,构建了带间隙碰撞振动模型,分析了不同间隙距离的碰撞振动对减振效果的影响.结果表明,间隙大小不影响平衡块的安装位置,但间隙超过0.002 m时,驱动装置所受惯性力随间隙增大而增大.Summary In the knife driving system of combine harvester,a slider-crank mechanism with a simple structure is used for driving the cutter bar.A low-cost balance mass is generally used in this mechanism to offset the unbalanced force for vibration reduction.The vibration characteristics of the knife driving system should be clarified in order to develop a method to reduce the vibration.Furthermore,it is necessary to develop a design theory of the knife driving system of combine harvesters in order to derive the control parameters of the balance weights used for vibration reduction. <br> The mechanical model of the knife driving device that is equipped with a slider-crank mechanism was constructed in order to derive the control parameters of the balance weights,such as the mass and the location of the balance mass.The simulation conditions of the model,which reflect the condition of the actual combine harvester, are listed.The angular velocity was equivalent to the rotation number of the crank wheel and was around 73 rad/s (700 r/min)in the clockwise direction.Vibration experiment was done with the type 4LZS-1.8 combine harvester.&nbsp;The vibration acceleration was measured using the preprocessing and cutting device of the actual combine harvester (the divider and conveying unit did not work;only the knife driving system worked).The interval time in calculation was set to 1 ms according to the sampling time of the measurement of the acceleration.The simulated inertia force was compared with measured acceleration in time series in order to evaluate the vibration model of the knife driving system.In the state without a balance mass,the simulation could express the vibration of the knife driving system well by comparing it with the measured acceleration.Consequently,this mechanical model could express the vibration characteristics of the knife driving system.The root mean square (RMS) value of the inertia force was simulated in the state with the balance mass in order to examine the effect of the vibration reduction.

关 键 词：联合收获机 切割器驱动装置 减振设计 时间序列分析 

分 类 号：S225.31[农业科学—农业机械化工程]