【作者】 惠东志；

【导师】 谢方平；

【作者基本信息】 湖南农业大学 ， 农业机械化工程， 2010， 硕士

【摘要】 移栽是当前烟草田间生产的主要栽植方式,但我国生产的烟苗自动移栽机,大都属于半自动机器。烟苗仍需人工供给,不仅劳动强度大,工作效率低,而且作业质量难以保证。因此要实现烟苗移栽的自动化,必须解决烟苗的供给问题。本论文的研究对象是烟苗自动移栽机中的重要组成部分—取苗机构。课题从基础理论分析和试验研究入手,通过分析获得取苗机构的主要组成部分,并通过计算确定机构的主要设计参数。利用Pro\E建立了虚拟样机模型,进行运动仿真。根据仿真结果对设计参数进行优化,并基本确定部件的结构形状。利用ADAMS软件对该虚拟样机模型进行动力学仿真,研究该机构主要部件的受力情况,对部件结构部分进行优化,使其满足力学要求。建立真实样机进行取苗试验,根据试验结果对部件结构再次进行优化,并确定主要影响因素的最终参数。试验结果表明,该机构可以完成预定功能。结论如下：1、烟草钵苗拔取试验表明：在正常情况下,单株烟苗抗拉断力远远大于从育苗穴盘中拔出烟苗所需的拔秧力,因此采用拔取方式取秧是可行的；对于烟草钵苗,苗夹通过夹取育苗基质的方式将烟苗从穴腔中取出,不易伤苗,且更容易实现定点夹苗,有利于取苗机构和送苗机构的设计。2、在理论分析的基础上,完成了取苗机构的设计。该机构通过曲柄滑块机构、双滑块机构、凸轮机构和平行四边形机构相互配合,完成取苗、送苗和落苗过程。并通过建力虚拟样机进行运动学和动力学仿真,对该机构进行优化,确定结构参数。该机构已获得国家发明专利。3、根据试验效果对机构的局部结构进行优化,并确定影响取苗效果的主要因素,经过试验确定主要因素的优化方案,曲柄转速为120n/min,苗盘倾角为64°,夹持力为4.3N。更多还原

【Abstract】 Transplantation is currently the main way of the tobacco plantation, but the most tobacco auto-transplanters made in china are semiautomatic machines.The seedlings still need to be manually supplied, which result in labor-intensive, low efficiency, and the quality of the work hardly to be guaranteed.It is necessary to resolve the problem of the seedling supply,to achieve the automation of the tobacco transplant.Picking seedling mechanism, which is the key component of the tobacco auto-transplanter, is focused on this dissertation. The task began with analysis of the basic theories and research of the experiments,the primary components of the picking seedling mechanism and the design parameters are obtained through analyzing and computing. The virtual prototype model is established by Pro\E,and its kinematics stability is simulated.According to the simulation results,the design parameters are optimized and the structural shape is confirmed preliminarily. Then its dynamics stability is simulated by ADAMS.Researching the stress of the main parts and optimizing the structural shape,which can satisfy stress requirements,is done.On the basis of the virtual prototype model,the experimental prototype is manufactured to finish picking seedling test and the structural shape is optimized again based on the results of the test and the structural shape is optimized again based on the results of the test while the ultimate parameters are confirmed.The results indicate that the machinery can implement the destined functions.The conclusions are as following.1、The results from the experimental research about the strength of pulling the seedlings from the trays show that the tensile strength of the seedlings is much larger than the strength of pulling seedlings from trays under the normal condition,so it is feasible to pull out the seedlings from trays.lt is not easy to hurt seedlings and more easier to implement picking seedlings at a fixed location through picking nursery substrate to pull out the tobacco seedlings from trays,which is benefical to design picking seedling mechanism and feeding seedling mechanism.2、Based on the theoretical anslysis,the design of the picking seedling mechanism is finished.It consists of slider-crank mechanism,double-slider mechanism,cam mechanism and parallelogram mechanism.Resulted from the coordination of the four mechanism,it can implement the processes of picking seedlings,transporting seedlings and droping seedlings in the same circle.The virtual prototype is established and its kinematics and dynamics is simulated.According to the designing results,the picking seedling mechanism is optimized and the structural parameters are confirmed.This mechanism has obtained national invention patent.3、according to the experimental results,the local structures are optimized,and the main factors which affect the result of the picking seedling are confirmed.The optimization of the main factors are confirmed,crank rolling velocity is 120n/min,the dip angle of the seedling tray is 64°,the strength of pulling out seedlings from trays is 4.3 N.更多还原