关键词: 小麦, 气吸式排种器, 离散元法, 正交试验

Abstract: Aiming at the problem of reduced seeding performance of the airsuction wheat seed metering device due to poor seed filling, a wheat airsuction precision seed metering device that assists in seeding and stirring the seed tray is designed. This type of seed metering device can use the hole boss to disturb the population during the seed filling process and at the same time, use the stirring plate to increase the dispersion of the population and improve the filling performance. In the seedcarrying area, the seeds are more easily stabilized and absorbed by the hole boss, reducing the negative pressure required for seed adsorption. EDEM was used to simulate the discrete element population of 4 different design seeding discs, and the variation of the average population velocity and the normal stress beating of the population of each seeding disc was analyzed. Taking the speed, air chamber pressure and the inclination angle of the stirring plate as factors, the orthogonal bench test was carried out on the optimal seeding plate designed. Through the variance analysis of the test results, the goodness of fit and regression equation for each test factor combination of the seeding performance index were determined. Finally, the multiobjective optimization of experimental factors was adopted, with the optimal conditions being the largest qualified index and the smallest replay and missed index. The best performance parameters for the designed seed metering device were obtained: the seed metering disk speed was 36.7 r/min, the air chamber pressure was -3.6 kPa, and the inclination angle of the stirring plate was 26.2°. The optimized results were tested and verified, and the error between the bench test results and the theoretical calculation results was less than 5%. This research can provide a reference for the optimization and improvement of wheat suction precision metering devices.

Key words: wheat, air suction seed metering device, discrete element method, orthogonal test