Design And Research On The Picking Seedling Machinery Of Tobacco Auto-Transplanter

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.