Kinematics Analysis And Optimal Design Of High-speed Rice Bowl Seedling Transplanting Mechanism

Rice bowl seedling transplanting technology is a transplanting technology withbowl seedling, through it the nutrient soil is fully reserved with rice seedling,compared with the seedlings by rice transplanter it rarely hurts the seedlings andmakes them strong and mature faster, so the rice bowl seedling transplanting canproduce continuable economic and social benefits. As the core working component,the transplanting mechanism determines the transplanting efficiency and quality, butthe efficiency of the domestic rice bowl seedling transplanting mechanism isgenerally low, the imported machine is also expensive and complex. Therefore, toacclimate the current rice cultivation situation in china, it has a strategic significanceto design a new&efficient rice seedling transplanting mechanism.Through institutional innovation, the structural parameters and influencingfactors of the trajectory were analyzed, one new high-speed rice bowl seedlingtransplanting mechanism was proposed, which can take seedlings, transplantseedlings and reach the action of seedling-pushing. At the same time, it has appliedfor a patent for invention (Application NO.:201410662412.1) and utility modelpatent (Patent NO.:201420696058.X).The major research contents of this paper are as follows:1) The research status of domestic and overseas transplanting mechanism forrice bowl seedling transplanter was discussed, and the pros and cons of rice seedlingtransplanting mechanism were analyzed, One new high-speed rice seedlingtransplanting mechanism was proposed, which can take seedlings, transplantseedlings and reach the action of seedling-pushing according to the agronomicrequirements and transplanting trajectory.2) The structural features and operational principle of seedling transplantingmechanism with crank-rocker planetary gear train were discussed and the theoreticalmodel was established, the existing shortage of the transplanting mechanism was analyzed and improved by software matlab, thus providing a theoretical basis forkinematics simulation analysis. According to the improved scheme, the3-dimensionalparts of seedling-pushing device was designed and simulated, the structural featuresand working principle were also introduced. After improvement, the mechanism canmeet the requirements of the transplanting trajectory and planting-agriculture, thevertical seedling height increased24mm and the planting depth increased15mm, theseedling-pushing device can also reach the action of pushing seedlings simulatinghand-planting, thus ensure the vertical degree and planting depth.3) The working cycle and force of seedling transplanting mechanism wereanalyzed, then established the dynamic model of seedling-pushing process and thecompression spring, the compression spring was analyzed and optimized carefully, atlast the effect of stiffness value of the compression spring to the quality of riceseedling transplanting was grasped and got a set of optimized parameters.4) Based on the optimal parameters, by drawing the2-dimensional partdrawings and assembly drawings in AutoCAD, the design problems of some coreparts in the seedling transplanting mechanism were avoided, the initial installationposition of the cam was confirmed. The3-dimensional parts and assembly model,base on three-dimensional modeling software CATIA, were builded and theinterference checking was completed, after completing the kinematics simulation byRecurDyn software, the simulation results of the improved rice seedlingtransplanting mechanism were analyzed and compared with the previous one, theresults showed that: the improved rice seedling transplanting mechanism wasfeasible.5) Manufacture and assembling of the seedling transplanting mechanism havebeen fulfilled. Thus, reliability of new seedling transplanting mechanism have beenfurther identified after completing the test of kinematics characteristics and effect ofworking.