借助高速摄影观察发现,水稻气力式精量穴播排种器吸种盘上吸孔所吸附的种子会由于吸力不足,在离心力作用下,在到达投种区前从吸孔附近落下,从而产生＂飞种＂现象,进而对排种器排出的每穴种子数量以及成穴性产生影响,降低排种精度。为此,设计了一种挡种装置,以含水率为21.1%的培杂泰丰种子为对象,采用多因素试验的方法,研究了不同吸室负压和不同排种盘转速下,安装挡种装置前后对＂飞种＂现象的影响;采用单因素试验的方法,研究了安装挡种装置后不同吸室负压下,不同排种盘转速对排种器吸种精度的影响。结果表明,安装挡种装置后,＂飞种＂出现范围减小,＂飞种＂出现的数量减少,排种器排种精度与成穴性能提高;当转速在25～40 r/min,吸室负压1.6 k Pa时,（1-3）粒/穴概率在93%～97%之间变化。试验结果显示安装挡种装置后能控制＂飞种＂的跌落范围,并使部分＂飞种＂落回充种室内,从而提高排种器排种精度。
In order to meet the agronomy demand for hybrid rice direct seeding,a novel precise pneumatic rice seed metering device was designed with groups of sucking holes plate,by which 3-4 seeds could be synchronously sucked and synchronously dropped into the paddy field.The plate was divided into five sections:seed sucking,seed clearing,seed carrying,seed dropping,and blank sections.The seeds were sucked in sucking section by the vacuum,carried and rotated to the dropping section with the plate,blown away in dropping section by the positive pressure air,and thrown into the dropping tube.The influences of the hole diameter,vacuum degree,and clear-up equipment on precision of metering device were discussed.Experiments were conducted to investigate the seeding precision and simulate the field emergence rates on the indoor seeding test-bed.The subjects were pregnant Indic hybrid Peizataifeng under two kinds of moisture content(23.43%and 26.07%).Other experiment conditions included the vacuum degree of 2.60 kPa,the rotation speed of seed sucking plate of 30 r/min,three sucking holes with a diameter of 1.6 mm,and the seed layer thickness of 25 mm.The seeding results showed that,in condition of no more than two seeds per hill,the emergence probabilities under the two moisture contents were 11.82%and 11.95%,respectively,and in condition of 3-4 seeds per hill,the results were 64.81%and 65.84%,respectively.With 2-5 seeds per hill,the results were 92.08%and 92.60%,respectively.If the emergence probability was 80%,under the two moisture contents,the no seed per hill probabilities were 1.33%and 0.80%respectively;the probabilities with 3-4 seeds per hill were 56.13%and 56.40%respectively;the probabilities with 5 or more seeds per hill were 10.67%and 10.13%respectively;the probabilities with 2-5 seeds per hill were 87.60%and 88.13%respectively.The results showed the simulated experiment was an efficient and economic method to assess the capability of pneumatic rice seed drilling metering device,and the precise pneumatic rice seed dril
为改善水稻种子在充种室内的流动性并提高水稻气力式精量穴播排种器的排种精度,实现超级杂交稻（1-3）粒/穴精量穴播要求,在水稻气力式精量穴播排种器与种箱间设计了一种分层充种室。以含水率为20.3%（湿基）＂培杂泰丰＂超级杂交稻种子为对象,采用单因素试验和正交试验的方法,研究了不同吸室负压、吹种正压下,分层充种室对排种器排种性能的影响。试验结果表明,在吸种盘转速为30 r/min、吸室负压为1.6 k Pa、送种正压为0.1 k Pa、采用分层充种室的条件下,该排种器排出（1-3）粒/穴种子的概率为95.4%,空穴率为1.53%,大于4粒/穴的概率为3.07%,其中排出1粒/穴种子的概率为17.32%,2粒/穴种子的概率为58.72%,3粒/穴种子的概率为19.36%;与前期开展的水稻气力式精量穴播排种器排种性能试验结果相比较,增设分层充种室后,排种器播种精度提高。该研究表明,减小排种器中水稻种子之间的挤压力和摩擦力,改善种子的流动性,从而使吸种盘上吸孔对种子的吸附能力增强,是提高水稻气力式精量穴播排种器的性能的重要途径。该文为水稻气力式排种器结构优化与性能提升研究提供了重要参考。
