Design And Tests Of Seedling Planting Mechanism Combined With Non-Circular Gear Train And Multilink

Globally,China’s vegetable planting area and output have exceeded 40 %,becoming the largest vegetable producer and consumer in the world.Seedling transplanting technology can significantly improve the survival rate of vegetables,shorten the growth cycle,and bring more economic benefits.Mechanized transplanting can not only improve work efficiency and reduce manpower,but also realize standardized planting.The planting mechanism is the core mechanism of mechanized transplanting,which directly affects the transplanting effect of vegetable plug seedlings.Referring to the relevant literature,it was found that the current seedling planting mechanism has the following problems : the duck-billed seedling planting mechanism would be adhered with a number of soil blocks in the clay environment,which is prone to block seedlings;The seedling pot is easy to be damaged and the plug seedling verticality is not easy to control due to the overall height of the seedling guide tube seedling planting mechanism is larger.Therefore,this paper proposes a seedling planting mechanism combined with non-circular gear train-multi-bar combined seedling planting mechanism,which is composed of seedling pushing mechanism and seedling supporting mechanism,and can realize wedge-shaped side seedling receiving mode,and carries out the working principle analysis,four-position motion synthesis,motion simulation,high-speed photography and seedling planting test.The main research contents are as follows :1)The interaction mechanism between vegetable plug seedling and guide tube seedling planting mechanism was analyzed,and the wedge-shaped side seedling receiving method was proposed to reduce the damage of the seedling pot.the collision mechanics modeling,EDEM discrete element simulation and plug seedling drop test were established.By comparing with the bottom plane collision seedling receiving method,the results show that the wedge side seedling receiving method can effectively reduce the damage degree of the seedling pot.2)The accurate four-position pose dimension synthesis method of open chain mechanism is introduced,and the comprehensive mathematical models of open-chain3 R and open-chain 2R are established.The motion defect identification of 2R and 3R mechanism was carried out,and the mechanism solution domain was established.The solution domain of the closed-chain five-bar mechanism is preliminarily constructed by combining the open-chain 2R and 3R mechanisms into a closed-chain five-bar mechanism and analyzing the conditions of its crank existence.3)The composition of non-circular gear train-multi-bar combined seedling planting mechanism and the working principle of plug seedling planting are proposed and analyzed.According to the seedling planting mechanism of the seedling planting mechanism,four key position points on the target trajectory of the seedling pushing board,as well as the rotation angle of the planet carrier,are given to complete the solution domain creation of the seedling pushing mechanism.The reasonable distribution of the transmission ratio of the two-stage non-circular gear and the method of generating the non-circular gear pitch curve are proposed.4)The motion trajectory of seedling pushing mechanism and seedling supporting mechanism was analyzed.The auxiliary analysis and calculation software of the five-bar seedling pushing mechanism of planetary gear train is developed by using MATLAB platform,and the parameter solution of the five-bar seedling pushing mechanism of planetary gear train is obtained.According to the calculation results,the cam linkage seedling supporting mechanism is designed to realize the coordinated movement of the seedling pushing mechanism and the seedling supporting mechanism.5)Complete the structural design of the seedling planting mechanism according to the parameters and working requirements of the seedling planting mechanism,establish a three-dimensional solid model of the mechanism in Solidworks,and import it into ADAMS for motion simulation.The correctness of the theoretical model and design of the seedling planting mechanism is verified by comparing the simulation analysis with the theoretical calculation results;Carry out component processing,prototype assembly,and test bench construction.Finally,an institutional seedling planting experiment was conducted to verify the working performance of the seedling planting mechanism prototype and its application feasibility.