导向充填式水稻精量穴播排种器孔-槽组合型孔设计与试验

针对水稻轻简型机械式排种器因稻种无序充填型孔，导致种群精量分离效果不佳，播量精确调节困难等问题，该研究基于稻种在齿盘疏导下的分布姿态规律，设计了一种具有导向充填效果的孔-槽组合型孔。构建了衡量型孔充种区域稻种分布姿态的评价方法，明确了该区域稻种姿态随时间的变化规律，分别确定了适宜于常规稻和杂交稻排种的大、小组合型孔的结构参数。以常规稻黄华占与杂交稻丰两优3948稻种为排种对象，以大、小进种孔宽度和振动频率为试验因素，依次开展了单因素、二因素全因子和品种适应性试验。单因素试验表明，当大进种孔宽度为6.8～7.6 mm、小进种孔宽度为4.6～5.2 mm时，排种器排种常规稻和杂交稻的合格率均大于85%；低频振动是影响排种器排种性能的主要振动工况。全因子试验表明，当大进种孔宽度为7 mm、小进种孔宽度为5 mm时，排种器的合格率基本不低于90%，并能适应不同的振动工况；品种适应性试验表明，在适宜的进种孔有效长度下，不同尺寸稻种的排种合格率不低于88.80%、漏播率不高于3.60%、破损率不高于0.16%。田间播种试验表明，大组合型孔播种黄华占时，各行合格率不低于89.33%、漏播率不高于1.60%、重播率不高于9.60%、穴径平均值44.64～54.83 mm、穴距平均值133.21～144.67 mm；小组合型孔播种丰两优3948时，合格率不低于85.73%、重播率不高于8.27%、漏播率不高于6.53%、空穴率不高于1.73%，穴径平均值39.88～45.59 mm、穴距平均值200.79～205.56 mm，均满足常规稻和杂交稻大田精量旱穴直播的种植要求。本文通过组合型孔不同大小进种孔的切换及进种孔有效长度的调整兼用于不同水稻品种不同穴播量的低损精量排种，为水稻可调播量排种器设计提供理论参考依据。

Design and experiment of the orifice-groove combined hole of the oriented filling type precision hill-drop seed-metering device for rice

High-speed seed filling can widely be used in rice planting in recent years. However, rice seeds filling hole in a disorderly manner has been resulted in the low precision separation of seed population. It is also difficulty in the precise adjustment during the seed filling. In this study, an orifice-groove combined hole of oriented filling type precision hill-drop seed-metering device was proposed to deal with the issue. A combination of waist round seed orifice and V-groove slot was also designed to adjust to the attitude change of rice seeds under the churning disturbance of tooth plate. The systematic evaluation was constructed to measure the distribution of rice seeds in the area of seed filling. The attitude change of rice seeds was then clarified with the time. The structural parameters of large and small orifices were determined suitable for the conventional and hybrid rice. Taking the conventional rice Huang Huazhan and hybrid rice Feng liangyou 3948 as the seeding objects, the single-factor, full factor, and variety adaptability experiments were carried out with the large and small orifice widths and vibration frequency as the experimental factors. The single-factor experiment showed that the qualifying rate of the seed-metering device was more than 85% for seeding conventional and hybrid rice, when the width sizes of the large and small orifice were 6.8-7.6 and 4.6-5.2 mm, respectively. Low-frequency vibration was the main vibration condition to dominate the seeding performance. The full factorial test showed that the qualified rate of the seed-metering device was not less than 90%, when the width sizes of the large and small orifice were 7 and 5 mm, respectively, indicating suitable for the different vibration conditions. The variety adaptability test showed that the qualified rates of different size rice seeds were not less than 88.80%, the miss-seeding rates were less than 3.60%, and the damage rates were less than 0.16% under the appropriate effective length of the orifices. The field seeding test showed that the qualified rates of various rows were not less than 89.33%, the miss-seeding and reseeding rates were less than 1.60%, and 9.60%, respectively, the average values of the hole diameter and spacing of various rows were 44.64-54.83, and 133.21-144.67 mm, respectively, when seeding Huang huazhan with the large combined orifice-groove. When seeding Feng liangyou 3948 with the small combined orifice-groove, the qualified rates of various rows were not less than 85.73%, the reseeding, miss-seeding, and empty-seed rates were less than 8.27%, 6.53%, and 1.73%, respectively, the average values of the hole diameter and spacing of various rows were 39.88-45.59, and 200.79-205.56 mm, respectively, all of which fully met the planting requirements of precision dry hill-drop direct seeding of the conventional and hybrid rice. Therefore, through the switching of different combined orifice-grooves and the adjustment of the effective length of the orifices, the seed-metering device can be expected to use for the low damage and precision seeding of various rice varieties with the different sowing amount. The finding can also provide the theoretical reference for the design of rice seed-metering device with the adjustable seeding amount.