Dynamics Analysis And Test Study On Pick-up Mechanism For Vegetable Pot-seedling Transplanter

With the improvement of people’s nutrition requirements, vegetable has gradually becomeone kind of the necessary foods in life. As the second major crops, vegetables have a significantposition in agricultural development and play an important role in the development of ruraleconomy. At present, vegetables (such as broccoli, tomato, eggplant, pepper and so on) mainlyare transplanted by the method of manual operation in china. It is very difficult to realizeplanting vegetables in large area because of the problems of artificial planting, such aslabor-intensive, low productivity, poor planting quality and high costs of production, whichlimits the further development of vegetable production in china. Increasing the study ofvegetable planting machinery and realizing the mechanization of vegetable transplantingbecomes the new target of agricultural development. Rotary pick-up mechanism for vegetableseedling is the main working part of automatic transplanting machine, which directly affects thevegetables planting quality and the production efficiency. Therefore, dynamic analysis and teststudy of automatic transplanting mechanism can provide an important basis for design andperformance improvement of vegetable transplanter, which has the important scientificsignificance and the value of application.Transplanting process is generally completed with the coordination of pick-up mechanismand seedling mechanism. At present, seedling planting mechanisms used in semi-automaticvegetable transplanting mechanisms, such as clamp type, chain clip type, seedling-guided tubetype and blanket-hanging type, are already mature. In the international market, although theyare more perfect, transplanting machines made in Japan have the questions of complex structure,high cost, common efficiency and domestic patent protection. It is urgent for China to developthe new type of auto-transplanting mechanism independently. However，study on the automaticseedling transplanting mechanism at home has just being started and they are short ofapplication, which becomes the weakness to restrict the development of automatic transplantingmachine. Therefore, the paper takes a new type of rotary vegetable seedling pick-up mechanismof planetary gear train with ellipse gears and incomplete non-circular gear (the utility modelpatent,authorization number:201120343300.1) which was invented by our study group as theresearch object to carry out kinematics and dynamics analysis of this mechanism, virtualprototype simulation and related experiments, which can provide an important basis for optimization design and production application of this mechanism. The main contents andresults of the research are as follows:(1) First, domestic and foreign development situation of vegetable transplanting machinewas studied. The working principle and structural features of vegetable seedling pick-upmechanism of planetary gear train with ellipse gears and incomplete non-circular gearwas analyzed. Kinematics model of the mechanism was improved and its kinematicsanalysis was completed. Through the virtual prototype simulation, correctness of thekinematics model and analysis had been vitrified, which may lay the foundation for thefollowing dynamics analysis.(2) It builds the dynamics model of the vegetable seedling pick-up mechanism of planetarygear train with ellipse gears and incomplete non-circular gear by using thedynamics-static method and solve the model with dynamics equations sequence solutionmethod. Asoftware was developed for dynamics analysis of the mechanism to figure outits dynamics performance.(3) Physical prototype of the seedling pick-up mechanism was manufactured and test benchwas built for completing dynamics test of the mechanism to acknowledge relationshipbetween the bearing reaction force of the mechanism and the rotary angle ofplanet frameunder the rotary speed of40r/min、60r/min、80r/min、100r/min and120r/min respectively.Through the results comparison of the dynamics test and the theoretical analysis tovalidate the correctness of dynamics model and analysis of the mechanism.(4) Instantaneous center line of add-in boards was increased to improve the structure of themechanism for optimizing its dynamics performance. Through the dynamics test andcomparison with the original dynamics results, it is proved that the mechanism withimproved structure has better dynamics performance and working stability.(5) To conclude the research work and results, point out the innovation of thesis and theprospects of follow-depth research work.