磁吸滚筒式排种器种箱振动供种仿真与试验

基于颗粒离散元法,以番茄磁粉包衣种子为对象,采用Hertz-Mindlin接触模型,建立了种子和排种器仿真分析模型,研究了种箱振动频率、振幅对种群运动规律及种箱供种性能的影响。仿真结果表明,在振动频率40 Hz、振幅0.50 mm和0.75 mm时,种群堆积高度稳定,可以达到稳定供种。为了验证仿真模型的可靠性,采用高速摄像拍摄了在种箱振动频率为40 Hz、振幅为0.75 mm条件下的供种情况,种子实际供种情况与仿真结果吻合。以种箱振动频率、振幅为试验因素,在磁吸滚筒式排种器上进行排种性能试验,得出种箱在振动频率40 Hz,振幅为0.50 mm和0.75 mm时,单粒率达92%,漏播率低于3%;在振动频率20 Hz和60 Hz时,不同振幅下的单粒率均小于80%。

Simulation and Experiment of Supplying Seeds in Box of Magnetic Precision Cylinder-seeder

Discrete element method was used to analyze the influence of working parameters on supplying seeds performance of magnetic precision cylinder seeder. Tomato powder coated seed was taken as the object of study, and then the seed and seeder simulation model was established. The mechanical interaction forces, both between seed and seeder and among the seeds were modeled by Hertz-Mindlin method(no slip). The effects of vibration frequency and amplitude on the seeds movement rule and the supplying performance were analyzed. The simulation results showed that when the vibration frequency was 40Hz and the vibration amplitude was 0.5mm or 0.75mm, the seeds accumulated a stable height and the ideal seeds supplying performance could be received, which was beneficial to improve suction precision. In order to verify the reliability of the simulation model, high-speed photography technology was used to record the supplying process with the seed box vibration frequency of 40Hz and vibration amplitude of 0.75mm, and the supplying results were consistent with the simulation results. Experiments were carried out on magnetic precision cylinder-seeder and the results showed that the single grain rate was greater than 92% and leak seeding rate was less than 3% with the seed box vibration frequency of 40Hz, vibration amplitude of 0.5mm and 0.75mm. The single grain rate was lower than 80% with vibration frequency of 20Hz and 60Hz, with different amplitudes.