气力滚筒式蔬菜穴盘播种机吸排种动力学模型的研究

为设计结构合理的气力滚筒式排种器,按单刚体系统对种子的吸排种过程建立动力学模型,结合试验研究影响吸排种效果的主要因素.在吸附阶段,选用合适的滚筒材料,提高种子与滚筒间的摩擦系数,适当增大气流量,减小种子与吸孔的距离,可以大大提高吸附效果.为保证种子能随滚筒转到排种位置,需限制滚筒的最大圆周速度,为此滚筒直径尺寸应适中,滚筒上吸孔按种子平均直径设计,并应合理调节吸种气腔内的真空度.在排种阶段,应优化设计滚筒气腔结构,使每行排种孔的流场分布尽量均匀,以尽量减小射流场对排种穴距不均匀的影响.

Dynamic model for metering process for pneumatic roller-type vegetable seeder

For designing high performance pneumatic roller-type metering device, the seed was simplified as single rigid body, its dynamic models during metering process was built. By theoretic analysis and experiments, main factors of seeding effects were discussed. During absorbing phase, properly selecting roller material to add friction coefficient between seeds and the roller, increasing airflow rate, decreasing distance between seeds and metering holes, the absorbing effect can be greatly improved. In order to ensure that the seeds can rotate with the roller to their metering positions, the metering holes should be designed according to the average seed diameter, the depression of air in the air chamber should be properly adjusted, and the maximum circumferential speed of the roller should be limited. Structure of air chamber should be optimized for achieving uniform air field distribution of each metering hole, to minimize the effects of jet stream on metering precision.