Experiments and analysis on seeding performance of seed feeding device of rapeseed centralized metering device under lateral tilt

In order to solve the problems that the surface unevenness leads to the tilt of the seed feeding device of centralized metering device in rapeseed mechanized seeding, which causes insufficient seeding stability, the seed feeding device of centralized metering device was taken as the research object, the working process of the seed feeding device was analysied and the mechanical models between rapeseed and the type hole of the seed feeding device were built at different lateral tilt angle during the seed filling, seed carrying and seed dropping process. The effects of lateral tilt angle perpendicular to work direction and rotating speed of seed feeding device on seeds quantity in type hole and seeds migration trajectory during seeding process were analyzed by EDEM simulation. The simulation results showed that with the increase of the tilt angle within 0°-5°, the average increase of seed quantity in type hole of the tilt side relative to the no tilt increased within 0-36.55%, and the average decrease of seed quantity in type hole on the other side relative to the no tilt decreased within 0-26.68% during seed filling and seed carrying process. The ratio ranged from 1.02 to 2.70 between the highest seed quantity of type hole 1 and the lowest seed quantity of type hole 4. During the process of seed dropping, when the rotating speed of seed feeding device was fixed, with the increase of lateral tilt angle ranged from 0° to 5°, relative to the no tilt state, the average seed quantity increase of seed dropping port I was 0-86.82% and the average seed quantity decrease of seed dropping port II was 0-75.65%, respectively As the rotating speed of the seed feeding device was 20 r/min and 40 r/min, the ratio of seed quantity of seed dropping port I to that of seed dropping port II was 14.4 and 5.29, respectively. The intelligent test platform of planting machines was used to test the effects of different lateral tilt and swing on seeding performance of the seed feeding device. The experimental results indicated that the average error of seed quantity between the bench test and simulation test was 3.86%, which showed that the simulation results were reasonable and credible. With the increase of the absolute value of the lateral tilt angle, the increase of the total seeding rate was 0.76%-8.72% compared with the total seeding rate without tilt. With the increase of the absolute value of the lateral swing angle, the change of the seeding rate of the seed dropping port I and II was 0-55.61% compared with the no tilt state, and the increase of the total seeding rate was 0.65%-4.23%. With the increase of lateral reciprocating swing, the increase of total seeding rate was 1.12%-9.02% compared with that of no tilt state. The test results showed that lateral tilt, lateral swing and lateral reciprocating swing had significant influence on seeding stability. The effects of lateral tilt and swing on seeding performance could be reduced by increasing the rotating speed of the seed feeding device. The results can provide reference for promoting the structure improvement and performance improvement of the seed feeding device.