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

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.

Keywords:Cyperus esculentus seeds;air-absorbing;two-hole parallel precision seed metering device