双孔并行气吸式油莎豆精量穴播器设计与试验

Design and Experiment of Two-hole Parallel Air-absorbing Precision Seed Metering Device for Cyperus esculentus

摘要:

针对大粒径油莎豆种子表面凹凸不平、尺寸差异大而导致穴播器充种、携种不稳定及难以实现精量播种的问题，结合油莎豆一穴2粒、等距穴播的农艺要求，设计了一种双孔并行气吸式油莎豆精量穴播器。以油莎豆为研究对象，阐述了穴播器的结构和基本原理，对穴播器关键部件进行设计，确定其结构参数，对充种、携种过程进行力学分析并构建种子动力学模型。采用Fluent仿真模拟分析双孔不同分布组合下不同位置截面流场的压力、速度分布情况，优选确定了型孔最佳组合方式。结合单因素试验，进一步分析影响穴播器排种性能的主要参数，选取排种盘转速、气室负压、型孔直径为试验因素，以合格指数、漏播指数、重播指数为排种性能评价指标进行三因素五水平二次旋转正交组合试验。对试验结果进行多元回归分析，确定影响穴播器性能指标的主次影响因素，并通过多目标优化确定最佳参数组合：排种盘转速为34.3r/min、负压为19.79kPa、型孔直径为6.83mm，对此参数组合进行台架验证试验，合格指数为92.1%，漏播指数为3.63%，重播指数为4.27%，满足油莎豆精量播种要求，提高了排种均匀性。

Abstract:

Aiming at the problems of uneven surface and excessive size difference of large particle size of the Cyperus esculentus, which led to the instability of filling and carrying of the seeding device, and it is difficult to achieve accurate seeding, a twohole parallel airsuction roller precision seed metering device for Cyperus esculentus was designed in accordance with the agronomic requirements of equidistant planting of two seeds in one hole. Taking Cyperus esculentus as the research object, the structure and basic principles of the seed discharger were elaborated, the key components of the seed discharger were designed, its structural parameters were determined, and the mechanical analysis of the seed filling and seed carrying process was carried out and a seed dynamics model was constructed. Fluent simulation was used to analyze the pressure and velocity distribution of the cross-section flow field at different locations under different distribution combinations of double holes, and the best combination of holes was optimally determined. Combined with the single factor test, the main parameters affecting the seed discharge performance were further analyzed. The rotation speed of the seed discharge disk, the negative pressure of the air chamber and the diameter of the mold hole were selected as the test factors, the three factor and five level quadratic rotation orthogonal combination test was carried out with the qualification index, the missing index and the reseed index as the evaluation indexes of seeding performance. Multiple regression analysis was carried out on the experimental results to determine the primary and secondary factors affecting the performance indicators of the seed discharge device, and the optimal parameter combination was determined through multi-objective optimization: the speed of the seed discharge disk was 34.3r/min, the negative pressure was 19.79kPa, and the diameter of the mold hole was 6.83mm. The results of this parameter combination were verified by bench test, and the qualified index was 92.1%, the missed sowing index was 3.63%, and the reseed index was 4.27%, which met the requirements of precision sowing for Cyperus esculentus and improved the uniformity of seeding.