油菜脉冲气送式排种器设计与试验OA

In response to the problems of uneven distribution of plant spacing and poor emergence uniformity in rows caused by seed jumping into the soil during the mechanized direct seeding process of oilseed rape in the rice-oil rotation area in the middle and lower reaches of the Yangtze River,a kind of impulse air-feeding seed discharger,which is used to take seeds from the seed-splitting wheel and cast the seeds by the assistance of impulse airflow,was designed.The seed force model of seed discharge process was constructed,and the main structural parameters of the seed discharger were analyzed and determined.Bench test analyzed the effects of seed separation wheel speed,air chamber cross-section ratio and airflow incidence angle on the seed discharge performance,and the results of orthogonal tests showed that:when the air chamber cross-section ratio was 4,the airflow incidence angle was 30°,and the speed of the seed separation wheel was 55 r/min,the seed discharge performance was better,and the index of qualification and the index of replanting were 90.74% and 3.70%,and the coefficient of variation of the spacing of the grains was 6.80%,respectively.High-speed camera analysis shows that the trajectory of rapeseed seeds leaving the seed displacer after airflow acceleration is nearly a straight line,and the average speed of rapeseed seeds is 1.40 m/s,which is much smaller than the collision speed of rapeseed breaking under the action of airflow.The results of the field test showed that the average plant spacing of rapeseed was 92.50 mm,and the coefficient of variation of plant spacing was 7.20%.