OPTIMAL DESIGN OF EJECTOR BELT SEEDLING COLLECTING MECHANISM BASED ON EDEM

In the seedling extraction mechanism of the ejection type, because the ejector rod is in direct contact with the seedling substrate, the fragmentation rate of the seedling is high, the success rate is low, and the seedling effect is poor. In order to solve this problem, combined with the interaction between the ejector rod and the bowl seedling, this paper analyzes the working principle of the ejector rod conveyor belt seedling harvesting mechanism, and optimizes the design of the ejector rod conveyor belt seedling harvesting mechanism. By using the method of EDEM simulation analysis and orthogonal experiment, taking the breaking rate and success rate of bowl seedling as the test response index, the effects of ejector rod end form, ejector rod diameter and seedling extraction speed were studied, and the results were analyzed by range analysis and variance analysis to analyze the influence law of the interaction of various factors on bowl seedling extraction. The simulation results show that the crushing rate of bowl seedlings increases with the increase of seedling speed and the decrease of ejector diameter. Among the three different types of ejectors, the effect of round head ejector is the best. The best parameter combination of the seedling mechanism is the diameter of the ejector rod 10mm, the seedling speed 2m/s, and the ejector rod in the form of round head ejector rod. The verification experiment shows that the seedling extraction effect of the optimized seedling extraction mechanism is better than that of the original seedling extraction mechanism. The results show that when the best combination of working parameters is used to collect seedlings, the qualified rate of seedlings is not less than 90%, the fragmentation rate is not higher than 20%, and the seedling performance is relatively stable. The optimized seedling extraction mechanism can be used in the automatic dryland bowl seedling transplanter to meet the operational requirements of the automatic transplanter.