Design and Experimentation on a Pneumatic Corn Seed Metering Device with Assisted Seed-Filling and Airflow-Guided Seed Release

In view of the problem that the qualified index of grain spacing deteriorates during high-speed operation of the pneumatic corn seed dispenser, a new method of homologous dual-action positive-pressure-assisted seed filling and seed release is proposed, and a pneumatic corn seed dispenser with assisted inflow filling is designed. The structure and working principle of the seed dispenser are explained, and a theoretical analysis is carried out on the seed filling and seed release process in the seed guide tube. The key structural parameters of the conical deflector-groove seed metering disc and the homologous airflow-assisted seed release mechanism are determined. The test factors were working pressure and operating speed, and the evaluation indicators were the qualified particle spacing index, missed sowing index, resowing index, and qualified particle spacing variation coefficient. A full-factor bench test was carried out, and the test results showed that when the sowing speed was 6 km/h and the working pressure was 5 kPa, the qualified particle spacing index was 96.37%, the missed sowing index was 0.30%, the resowing index was 3.33%, and the coefficient of variation in the qualified particle spacing was 17.37%. The results of the field test showed that when the operating speed was 6 km/h and the working pressure was 5 kPa, the qualified particle spacing index was 95.30%, the missed sowing index was 2.33%, and the resowing index was 2.37%. All indicators met the technical requirements for precision single-seed maize sowing.