Abstract:In order to improve the filling performance of seed metering device with roller of air-suction, the numerical simulation on the height of seeds layer, the vibration frequency and the angle of vibration were carried out with method of discrete element analysis. The results showed that the arc length in the area of filling seeds and the time of filling seeds can be increased through increasing the height of seeds layer. The leakage rate can also be reduced under the same conditions; the mean value of normal stress was increased with the increase of vibration frequency, which meant that the disturbance to the seeds can be enhanced; the proper vibration angle can increase the height of filling seeds effectively. The filling performance of the seeds metering device can be improved effectively by reducing the internal friction force, enhancing the disturbance of the populations and increasing the height of filling seeds. Maize seeds (Zhengdan 958) were taken as research materials in order to determine the optimal combination of parameters. The seeding performance of metering device was studied through the quadratic rotation-orthogonal combination experiment. The height of seeds layer, the vibration frequency and the vibration angle were taken as main factors. The qualified rate, leak seeding rate and the re-seeding rate were taken as indexes. The mathematical model between three factors and the indexes was built. The effect of each factor on the qualified rate was analyzed and optimized parameters were tested. The effect of factors on the qualified seeding rate in primary sequence was the negative pressure, forward speed and angle of seeds suction. The optimal parameters were obtained. The qualified rate was above 90%, the leak seeding rate was lower than 5% and the re-seeding rate was also lower than 5%, when the vibration angle was 45°, the vibration frequency was 116~122Hz and the height of seeds layer was 96~117mm. The results of the verified experiment were consistent with optimal results. Conclusions can be drawn that the seed metering device with roller of air-suction had good adaptability to maize seeds. References for the design of the maize seeds metering device with roller of air-suction can be provided.
