Authors

Abstract

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.

Abstract in Chinese

在顶出式取苗机构中，由于顶杆与钵苗基质直接接触，钵苗破碎率高，成功率低，育苗效果差。为解决这一问题，结合顶杆与钵苗的相互作用，分析了顶杆输送带取苗机构的工作原理，并对顶杆输送带取苗机构进行了优化设计。采用EDEM模拟分析和正交试验的方法，以钵苗基质破碎率和取苗成功率为试验响应指标，研究了顶杆端部形状、顶杆直径和取苗速度对取苗效果的影响，并对结果进行极差分析和方差分析，分析各因素交互作用对取苗效果的影响规律。模拟结果表明，钵苗破碎率随取苗速度的提高和顶杆直径的减小而增大。在三种不同类型的顶杆中，球头顶杆的效果最好。取苗机构的最佳参数组合为顶杆直径10 mm，取苗速度2m/s，顶杆形式为球头顶杆。验证实验表明，优化后的取苗机构取苗效果好于原取苗机构。结果表明，采用最佳工作参数组合取苗，取苗合格率不低于90%，破碎率不高于20%，取苗表现相对稳定。优化后的取苗机构可用于旱地钵苗自动移栽机，满足自动移栽机的作业要求。