【作者】 尹大庆；

【导师】 王金武；

【作者基本信息】 黑龙江八一农垦大学 ， 农业机械化工程， 2014， 博士

【摘要】 中国土地资源匮乏，增加玉米产量主要依靠提高单产。玉米移栽可以延长作物生育期，大幅度提高产量和品质。国际先进的移栽机械，结构复杂、成本高、效率低，只能用于经济作物。用于玉米的移栽装备在国内外仍处于空白，国内急切需要结构简单、成本低、效率高的全自动玉米移栽机。本文对玉米钵苗移栽机核心工作部件有序顶出式分秧机构的机理和参数优化做了系统的研究。着重对机构的运动学和动力学进行了分析和优化，并进行了机构的ADAMS和ANSYS联合仿真分析。通过建立的杠杆有序顶出式分秧机构试验台上进行的试验研究，为全自动高效、轻简化玉米移栽机提供自主创新的核心工作部件和理论与技术基础。主要结论如下：1)通过分析国内外分秧机构的工作原理和结构特点，针对玉米钵苗移栽采用顶出式有序分秧模式和连续转动输送的纵向送秧；2)玉米钵苗在育苗过程中为了避免盘外盘根现象，钵盘底部以外不能存有土壤；试验的特定土壤条件下，含水率在18%左右时有利于提高玉米钵苗的顶出成功率和高效率；3)基于从动件最大有效受力而提出的“渐开线反转法”设计偏心直动盘形凸轮的轮廓曲线，该方法简单且精度高；4)通过ADAMS与ANSYS的联合仿真，对关键部件的应力、应变和位移等参数进行了仿真分析和对比，对拨杆和杠杆的结构进行了优化，结构更加合理，节省了成本；5)所编制的机构运动参数优化软件给机构设计提供了依据，优化方法具有快捷性、灵活性和可靠性。发现在优化目标值基本不变的情况下可以得到系列的“非劣解”群，这为实际设计时带来了很大的方便；6)顶杆复位弹簧的参数影响顶杆复位时间和受力大小，以满足复位时间和最小受力为目标编制的弹簧参数优化软件为弹簧的设计提供了依据。得到的一组优化参数为：d=0.8mm，n=14，△x0=49mm，对应该组参数，k=0.167N/mm，弹簧最大作用力F=14.88N，理想状态下顶杆复位时间为t=0.01s；7)试验结果表明，杠杆有序顶出式分秧机构工作效率高于每分钟300次；高速摄像的结果证明玉米钵苗分秧后是有序的，时间间隔基本一致。试验结果证明理论分析和优化结果是合理的，方法是正确的。更多还原

【Abstract】 In order to increase the output of corn, the best way is to increase the output per ha Becauseof short of soil in China. Based on the procreating period being prolonged by corn transplanting,the output and quanlity of corn are to be increased. Structures of transplanting machines ataboard are complex and price of them are high and the efficiencies of them are low. And at homecorn transplanting machine is none. So full automatic corn transplanting machine is urgentlyneeded, which structures of transplanting machines at abroad are simple and price of them arelow and the efficiencies of them are high.Systemtically studies on mechanism and parameters optimization on key parts of theorderly push-out separating seedling mechanism for transplanting corn were maken. Andanalyses and optimization on the kinematics and dynamics of mechanism are emphases.Simulations of mechanism were done by ADAMS and ANSYS. Experimental studies were doneon the test bed of the orderly push-out separating seedling lever mechanism, which could providefreedom innovation of key parts and theory and technical basis for full automatic higheffienciency and light corn transplanting machine.The conclusions are as follows.1) Through analyzing the work principles and structural characteristics of separatingseedling mechanism at home and abroad, for corn seedling transplanting, orderly push-out modeland continuous rotating delivering portrait seedling were chosen.2) In order to avoid the phenomenon of entangle root outside of corn pot seedling plate, nosoil exist outside of it. Based on the special soil, moisture of soil was18%that was best toincrease the ratio of success and high efficiency of corn seedling pushed out.3) Based on the biggest bearing force of driven parts, involute reversed was put forward todesign profile construction of partialital straight moving tray cam, which was simple andprecise.4) Through simulation by ADAMS and ANSYS combined, stress and strain anddisplacement of key parts were obtained and analyzed. The structures of dial rod and lever wereoptimized. And the results were more in reason. And the material cost was saved.5) The soft was workout to optimize the moving parameters of mechanism, which wereshortcut and agility and reliable. Under the same target values optimized, a series of non badsolution group, which was very convenien for actual design.6) The time and bearing force of mandril returning were effected by parameters of mandril reposition spring. In order to satisfy the reposition time and make bearing force least, the softwas workout to optimize the parameters of spring. The results of optimization were thatd=0.8mm，n=14，△x0=49mm，and bearing force of spring F=14.88N，the time of mandrilreturning were t=0.01s under ideal conditions.7) The results of test show that the efficiency of lever push-out separating seedlingmechanism was higher than300times per minute. The results of high speed video show thatcorn pot seedling separated was orderly and the time were basic consistent. So the theorical andoptimized results were in reason, which showed that the method was correct.更多还原