Study on influencing factors of hole-filling performance of rice precision direct seed-metering device with hole ejection

Designing improved rice direct seeding metering devices is crucial for improving rice planting mechanisation. The performance hole formation of the device will directly affect the precision sowing and yield. Current devices are limited by their structure and concentration on accuracy and low seeding rate, which causes hole-filling performance to decrease as the seeding rate increases. This study analyses the main factors affecting hole-filling performance based on the device with hole ejection. An optimisation experiment was conducted to determine the optimal parameters with seeding performance as the primary index. Firstly, it was determined that rotational speed and spring force are the primary factors affecting the hole-filling performance. The coupling simulation study determined that the rotational speed should not exceed 40 r min−1, and the spring force should not exceed 15 N. Secondly, the quadratic rotation orthogonal experiment was designed, and the experiment platform was built to conduct the investigation. The results show that when the rotational speed is 29.86 r min−1, and the spring force is 13.94 N, the qualification rate of hole diameter, the average hole diameter, the coefficient of variation of hole diameter, and the coefficient of variation of hole spacing are 97.99%, 37.3 mm, 20.99%, and 8.41%, respectively. Finally, a field experiment demonstrated that the device had good hole-filling performance under four different hole spacing, which met the requirements of direct seeding of rice. This study provides methods and reference data for the development and performance improvement of rice precision direct seed-metering devices.