巨菌草排种器排种过程动力学仿真分析及试验研究

Dynamic simulation analysis and experimental study on seed metering process of giant Juncao metering device

为改善巨菌草种植机易伤种、排种流畅性差的问题,对现有巨菌草种植机核心部件排种器的作业参数进行优化.利用激光三维重构技术建立了巨菌草种茎三维模型,结合虚拟样机技术建立排种器刚柔耦合模型,运用虚拟样机对排种过程进行动力学仿真,并通过台架试验验证了仿真模型的正确性.排种器送种辊转速为30 r·min^(-1),预排种箱种茎个数为6,巨菌草种茎直径为18~22 mm,预排种槽中种茎排放次序按种茎直径大小层叠排放,预排种槽与送种辊上表面间距为12.05 mm,上述条件下送种辊所受平均扭矩值为0.0828 N·m^(-1),排种速度波动率为7.3%,漏种指数为2.5%,重播指数为0.排种完成后种茎表面无明显刮痕,芽节与茎秆无撕裂、挤压等损坏发生,排种流畅,各项指标符合巨菌草种植的农艺要求.

In order to solve the problems of easy damage and poor seed flow for giant Juncao planter,the operation parameters of the seed metering device and the core component of existing giant Juncao planter were optimized.Three-dimensional model of the stem of giant Juncao was firstly established using laser-based three-dimensional reconstruction technology,then the rigid-flexible coupling model of the metering device was established with the aid of virtual prototype technology.The dynamic simulation of the metering process was carried out using the virtual prototype,and lastly bench test was conducted to verify the accuracy of the simulation model.The results showed that when the roller revolved at the speed of 30 r·min^(-1)and the quantity of seed stem loaded was 6 in the seed slot,with the diameters of seed stem ranging between 18 and 22 mm,seed stem can be rearranged and stacked by seed diameter in the groove.When the distance between seed slot and the upper surface of the roller was 12.05 mm,the average torque which the roller beard reached 0.0828 N·m^(-1),with the fluctuation rate of metering speed,missed seed rate and repetitive seeding rate being 7.3%,25%and 0,respectively.The overall seeding process was fluent,resulting in barely scratched stem seed surface and no avulsion and extrusion for shoots and stems,which was in accordance with the agronomic requirements of Juncao cultivation.