双列限姿导引侧充式玉米高速精量排种器设计与试验

    Design and test of a double-row high-speed precision corn seed metering device with guided side-filling and posture control

    • 摘要:
      目的  针对现有的机械式玉米排种器在高速作业条件下播种质量下降的问题,设计一种双列限姿导引侧充式玉米高速精量排种器。
      方法 采用限姿板配合排种盘和护种盘分级限制引导种子侧充进入充种型孔前的姿态,同时利用径向突变结构辅助种子自重清种,实现高速精量排种作业。结合玉米种子的形状特征与尺寸,分析种子分级限姿导引侧充的原理,确定关键部件的基本结构参数。运用离散元法与多体动力学(Discrete element method and multi-body dynamics, DEM-MBD)耦合的方法,以型孔插件顶部宽度、护种盘后侧高度以及护种盘底部角度为试验因素,以合格指数、重播指数与漏播指数为评价指标,设计二次正交旋转回归组合仿真试验,并开展台架试验验证仿真试验的可靠性。
      结果 仿真试验结果表明:在作业速度为12 km/h 时,型孔插件顶部宽度为4.65 mm护种盘后侧高度为5.10 mm护种盘底部角度为81.86°时,玉米排种质量最优,此时排种合格指数、重播指数和漏播指数分别为92.18%、5.13%和2.69%。台架验证试验结果表明:在作业速度为12 km/h 时,排种合格指数为91.45%,与仿真试验的相对误差为0.79%,仿真优化试验结果可靠;在作业速度为8~16 km/h时,合格指数均大于90%,重播指数均小于7%,漏播指数均小于4%,且排种效果优于传统的勺轮式排种器。
      结论 设计的排种器对作业速度的适应性较好,满足玉米精量播种的技术要求。

       

      Abstract:
      Objective Aiming at the problem that the existing mechanical corn seed metering device decreases the seeding quality at the condition of high speed operation, a double-row high-speed precision corn seed metering device with guided side-filling and posture control was designed.
      Method The posture limiting plate, combined with the seed metering plate and the seed protection plate, was used to limit and guide the posture of seeds before side-filling into the seed filling holes in stages. Meanwhile, the radial mutation structure was used to assist the gravity seed cleaning to achieve high speed and precise seeding. Based on the shape characteristics and dimensions of corn seeds, the principle of staged posture control and guided side-filling and the basic structural parameters of key components were determined. Using the coupled discrete element method and multi-body dynamics (DEM-MBD) approach, with the top width of the orifice plug, the rear height of the seed protection plate, and the bottom angle of the seed protection plate as test factors, and with the qualified index, replay index and leakage index as evaluation indexes, a quadratic orthogonal rotational regression combined simulation test was designed, and the reliability of the simulation test was verified by bench test.
      Result The simulation results demonstrated that under an operating speed of 12 km/h, the optimal corn seeding quality was achieved with the following parameters: Orifice plug top width of 4.65 mm, rear height of the seed protection plate of 5.10 mm, and bottom angle of the seed protection plate of 81.86°. Under these conditions, the qualified index, replay index, and leakage index were 92.18%, 5.13%, and 2.69%, respectively. Bench validation tests indicated that at 12 km/h, the qualified index reached 91.45%, showing a relative error of 0.79% compared to the simulation results, thereby confirming the reliability of the simulation optimization. Furthermore, within the operating speed range of 8–16 km/h, the qualified index consistently exceeded 90%, while the replay index and leakage index remained below 7% and 4%, respectively. The seeding performance was notably superior to that of traditional spoon-wheel seed metering devices.
      Conclusion The designed seed metering device exhibits good adaptability to varying operating speeds and fulfills the technical requirements for precision corn seeding.

       

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