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

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.