Research And Design On Vacuum Cylinder Precision Seeder Of Rice

As a core component of precision sowing technique, seeder’s working performance directly influenced the sowing accuracy, seed spacing uniformity and emergence rate. Precision seeding of existing can only be applied to meet the needs of conventional seedling of rice which 3-5 seeds per hole, and it is difficult to meet the precise demands of super hybrid rice planting which 1-3 seeds per hole. Through further study of the domestic and foreign existing precision seeding device, this paper analyzed the merits and shortcoming of diversified sowing devices. According to the combinations of vibrating-plate and vacuum cylinder for plug seedling of super rice, this paper designed a Precision seeding device, achieved the precise positioning of seeding. The mechanical models of seeds in the adsorbed phase and with the vacuum cylinder rotate phase were established after analyzed the sowing phase of the vacuum cylinder. Through the mechanical models we can find that the important operating factors for obtaining high seeding rates were typically the suction hole shape, suction hole diameter, vacuum pressure and the rotation speed of the roller. When the suction holes were in the same sizes, through CFD analysis we found that the straight hole shape has a highest seeding rate. Effects of suction hole diameter and vacuum pressure on the seeding rates were when choose straight shape hole. At last, analyzed different cases of the suck seed and seed sowing in the different types suction pore which in different rotational speed and suction pressure of the vacuum cylinder device by experiment. Combined data processing system, established the regression mathematic model of the cave rate of lacking and the enter rate of 1-2 by multivariate regression analysis. By optimizing the processing, when the suction hole was 1.41mm and vacuum pressure was 4298.5Pa, the vacuum cylinder has a cave rate of lacking 5.56% and enter rate of 1～2 86.61%.This paper gained some useful regular patterns through theoretical analysis, Simulation and experimental study. These provided a theoretical basis for parameter design and further improve performance of precision sowing device.