【作者】 王文明；

【导师】 王春光；

【作者基本信息】 内蒙古农业大学 ， 农业机械化工程， 2012， 博士

【摘要】 捡拾压捆机是牧草收获机械的一种，弹齿滚筒式捡拾装置是捡拾压捆机的主要工作部件之一，对捡拾装置进行深入研究对我国提高捡拾压捆机的工作性能，实现牧草收获机械化有重要的现实意义。我国对弹齿滚筒式捡拾装置尚没有明确的设计方法，所有捡拾装置的设计均参照国外相应参数仿制，不清楚各结构参数如何匹配才是最优的，才能更好地实现捡拾作业，也不清楚控制弹齿运动的凸轮滑道廓线应设计成何种形状才是最优的，才能使捡拾装置在工作时弹齿的漏捡区域小，速度变化合理，各零件受力小，功率消耗小。论文通过理论分析、计算机仿真模拟以及试验测试对弹齿滚筒式捡拾装置的捡拾过程进行了研究。在此基础上，对弹齿滚筒式捡拾装置的结构参数及工作参数进行了改进设计。（1）对弹齿滚筒式捡拾装置进行了机构分析，确定了弹齿滚筒式捡拾装置的机构性质，反转的摆动从动件盘形凸轮机构；分析了弹齿的运动，并在此基础上建立了弹齿端部的数学模型。（2）确定了影响弹齿滚筒式捡拾装置捡拾效果的影响因素，其主要是特征参数λ的取值和凸轮机构参数。其中λ的大小取决于机器前进速度V t、滚筒回转角速度ω（即转速n）和凸轮机构参数。（3）得出了满足捡拾装置工作要求的凸轮机构运动规律。（4）应用虚拟样机技术，利用机械系统设计软件Pro/Engineer和机械系统分析软件ADAMS建立了捡拾装置的参数化模型；计算机仿真分析了9KJ^-1.4A小方捆捡拾压捆机捡拾装置：捡拾装置原凸轮滑道廓线设计和参数匹配使弹齿运动过程中漏捡区面积较大且加速度较大而有突变。在ADAMS环境下用相对轨迹生成实体的方法，对弹齿滚筒式捡拾装置的凸轮滑道廓线进行了改进设计。经过改进设计，找出了捡拾装置结构参数的最佳值和工作参数的最佳匹配关系。滚筒半径R=125mm，曲柄长度l=80mm，弹齿长度l’=178mm，弹齿与曲柄夹角=1.1rad,滚子半径r=17.5mm，弹齿杆数z=5。机组工作速度V t5km·h^-1，滚筒转速n=64r·min^-1，凸轮运动规律：升程和回程均采用正弦加速度运动规律。（5）对改进设计前后的弹齿滚筒式捡拾装置进行了加速度测试分析。采用微型无线加速度传感器测试了弹齿端部的加速度，结果表明：改进设计后的弹齿端部加速度值明显减小，且加速度值无突变，改善了弹齿滚筒式捡拾装置的工作性能，加速度测试分析结果与仿真分析结果一致。（6）对改进设计前后的弹齿滚筒式捡拾装置进行了捡拾损失率和功率消耗测试分析。结果表明：在功率消耗与改进前基本相同的情况下，改进设计后的捡拾装置的捡拾损失率有了较大减小，说明改进设计后的参数更趋于合理。（7）用高速摄像方法分析了捡拾装置捡拾作业过程，分析结果表明：改进设计后的捡拾装置在弹齿放齿、捡拾、升举、推送和收齿等阶段，弹齿的运动规律能够满足使用要求，速度方向变化合理，且在捡拾过程中，弹齿端部没有产生过高的加速度，加速度没有突变现象，较平稳。高速摄像分析结果与仿真分析结果一致。更多还原

【Abstract】 Pickup baler is one of the grass harvest machine. Spring-finger cylinder pickupcollector is the main working parts of pickup baler. Profound study in spring-fingercylinder pickup collector is most significant for improving service behavior of pickupbaler and implementing mechanized harvest of pasture. There is no definite designmethod in designing spring-finger cylinder pickup collector. In our country, theparameters of pickup collector are in imitation of foreign. We do not know the optimummatching parameters that pickup working putting into effect well. And we do not knowthe optimum cam shape with smaller leakage collecting area, proper velocity variation,less stress on parts and less power consumption of pickup collector. Aiming at theproblems, theoretical analysis, kinematics simulation and experimental test for study ofthe working process of spring-finger cylinder pickup collector are carried out. Based onthe achievement, the structure parameters and the working parameters of pickup collectorare improved.（1） Mechanism analysis of spring-finger cylinder pickup collector is charified. It is adirection changing cam mechanism with oscillating follower. The movement ofspring-finger is discussed also. Based on the discussion, the mathematical model ofspring-finger is established.（2） The chief factors to affect the function of the pickup collector are analyzed. Themain parameters to affect the function of the pickup collector are λand parameters ofcam mechanism. The value of λ is determined by heading velocity, rotational angularvelocity of cylinder and parameters of cam mechanism.（3） The moving law of cam mechanism satisfying the demand of pickup working isacquired.（4） In the course of study, a modern designing theory was introduced and a computeraided analysis to the pickup process of the pickup collector is conducted by means ofPro/Engineer designing software, ADAMS analytical software of mechanical system andhaving established a ADAMS model for the pickup implement of the collector. By goingthrough kinetics analysis, the working status of pickup collector with original parametersis required. The leakage collecting area of spring-finger cylinder pickup collector withoriginal parameters is bigger and acceleration of the end of spring-finger is larger anddiscontinuous. The essential design parameters of pickup collector are improved also.Based on the achievement, the affecting laws of the variation of each factor to the moving state of spring-finger and appropriate design method of slide track cam areacquired. Working parameters of cylinder pickup collector at given structure parametersare found. The radius of cylinder is125mm, the length of crank is80mm, the length ofspring-finger is178mm, the angle between spring-finger and crank is1.1rad, the radiusof roller is17.5mm, the quantity of spring-finger rod is5, heading velocity of pickupcollector is5km·h^-1, and rotational speed of cylinder is64r·min^-1. The cam law in liftingand returning stage is sinusoidal acceleration moving rule.（5）The acceleration testing analysis is offered with original parameters and improvingparameters of pickup collector. The result indicates that the acceleration value of the endof spring-finger reduces after improving and it is continuous. It shows that the analyticalresults of simulation are good agreed with the experiment results. This result shows thefeasibility of using simulation method to analyze the performance of the cylinder pickupcollector.（6） The pickup loss factor and consumed power with original parameters andimproving parameters of pickup collector are acquired. The result shows that the pickuploss factor after improving is reduced. Consumed power is as the same as pickupcollector with original parameters. It indicates that parameters after improving are morereasonable.（7） The overall movement process of spring-finger and material is photographed online by using the high-speed photography equipment. By going through collection andanalysis of image sequence, the relative movement law between spring-finger andmaterial agrees with the requirement of picking material. The velocity of spring-fingervaries reasonable and the acceleration of spring-finger is continuous. It shows that thesimulation results are agreed with the experiment results.更多还原