Abstract:

: In disturbance-assisted seed filling vacuum seed-metering devices, the suction hole causes difficulty in quickly and stably sucking seeds when used for high-speed seeding and the large working negative pressure demand is used. To address this difficulty, this study’s authors designed a seed disk hole with a variable cross-section structure, and the groove depth, which has the function of assisting seed filling, was optimized. Using the combined method of Fluent numerical analysis and an orthogonal experiment, the influence of the shape, inlet diameter, and length of the seed disk hole on the pressure difference of the seed disk hole was analyzed. The working process of the vacuum seed meter was simulated and analyzed by the Discrete Element Method and Computational Fluid Dynamics coupling method. It was found that with the increase of the diameter of the seed disk hole, the pressure difference decreased, and the length of the seed disk hole had little effect on the pressure difference. The best diameter of the seed disk hole was 5.4 mm, and the length was 5 mm. It was found that the pressurization effect of the arc-shaped seed disk hole is better. With the increase of groove depth, the leakage rate shows a trend of first decreasing and then increasing, which was determined to be 1.5 mm. The verification experiment proved that the working performance of the optimized seed metering device is better than that of the original one. The results show that when the working negative pressure was 4 kPa and the working speeds were 8~14 km·h −1, the qualified rate was not less than 95.0%, and the seed filling performance was relatively stable. The optimized vacuum seed metering device can be applied to high-speed seeders, while ensuring the requirements of high-speed sowing operations.

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