基于DEM-MBD耦合的链勺式大蒜精量排种器设计与试验

Design and Test of Chain-spoon Type Precision Seed-metering Device for Garlic Based on DEM-MBD Coupling

摘要:

针对现有大蒜精量排种装置漏播率高、取种单粒率低等问题，设计了一种链勺式大蒜精量排种器，阐述了排种器结构和工作原理，对其关键部件进行了优化设计，分析了排种器工作过程，确定了影响其作业性能的关键因素，建立了排种器DEM-MBD耦合仿真模型并进行了单因素仿真试验，探究了排种器不同工作参数对作业性能的影响，以主动链轮转速、种层高度和充种区排种链条倾角为试验因素，以取种单粒率、漏充率和重充率为试验指标，进行了二次回归正交旋转组合仿真试验，建立了各试验指标与试验因素的回归模型，并确定了排种器最优作业参数。试验结果表明，当主动链轮转速为23.1r/min、排种链条倾角为67.6°、种层高度为301.5mm时，工作性能最佳，此时取种单粒率为92.5%，漏充率为2.5%，重充率为5.0%。为了验证优化后排种器作业性能，进行了台架试验，试验结果与回归模型预测结果基本一致，该研究为链勺式大蒜精量排种器及其关键部件优化设计提供了参考。

Abstract:

A new type of chain-spoon type garlic precision seed-metering device was designed to solve the problem of the high missing rate of the previous devices. The overall structure and working principle of the seed-metering device were explained and analyzed, the design of its key components was optimized, the working process of the seed-metering device was analyzed, and the key factors affecting its operational performance were identified. A single-factor simulation test based on EDEM-RecurDyn coupled simulation was conducted to investigate the effects of active sprocket rotational speed, seeding chain inclination in the seed-filling zone, and seed layer’s height on the seeding performance. Besides, a quadratic regression orthogonal rotational combination simulation test was carried out with the active sprocket rotational speed, seed layer’s height, and seeding chain inclination angle as test factors and the single seed picking rate, missing rate, and replay rate as test indicators. A regression model of the evaluation indicators and test factors was established, and the parameters of the test factors were optimized. The test results showed that the best performance was achieved when the active sprocket rotational speed was 23.1r/min, the seeding chain inclination angle was 67.6°, and the seed layer’s height was 301.5 mm. At this time, the rate of single seed-picking was 92.5%, the missing rate was 2.5%, and the replay rate was 5.0%. Bench tests were carried out to verify the seed-metering device’s operational performance, and the results generally agreed with those predicted by the regression model. This study provides a reference for the optimized design of chain-spoon type garlic precision seed-metering device and its key components.