Abstract: In order to further improve the sowing accuracy of hybrid rice bowl seedling raising, this paper aims to address the problems of high resowing index, high seed crushing index, and unequal number of seeds per hole in the operation of the original intelligent double filling hole roller hybrid rice seedling raising precision planter. A secondary seed clearing area was added to improve the structure of seed protection parts of the planter. The improved planter relies on the double seed filling mechanism to complete the roller hole seed filling, and further improves the sowing accuracy of 1-3 seeds per hole through the measures of twice seed cleaning, seed protection, and forced seed injection into the hole. The improved principle prototype was trial produced. Taking Teyou 2068 budding rice seed as the test material, the effects of productivity, installation clearance of seed cleaning wheel, and inlet opening of seed protection parts on the sowing qualification index, resowing index, and seed damage index were studied using a threefactor and threelevel orthogonal test method. The results showed that the primary and secondary order of the factors affecting the sowing qualification and replanting index was as follows: productivity、 installation clearance of seed cleaning wheel、 inlet opening of seed protection parts. The primary and secondary order of the factors affecting the seed damage index was: productivity、 inlet opening of seed protection parts、 installation clearance of seed cleaning wheel. Under the optimal parameter combination of 400 discs/h productivity, 2 mm installation clearance of seed cleaning wheel, and 3 mm inlet opening of seed protection parts, the sowing performance of Teyou 2068 and Wuyou 1179 with similar triaxial size and Hengfengyou 1179 with certain differences were compared before and after the improvement. The results showed that Teyou 2068 and Wuyou 1179 with similar sizes had good adaptability. The sowing qualification index reached 94.8% and 94.6%, which increased by 2.6% and 2.9%, respectively, compared with before the improvement. The resowing index decreased by 17% and 2.2%, respectively, and the seed damage index decreased by 2.9% and 3.6%, respectively. The experimental indexes met the technical requirements of low sowing rate precision sowing of hybrid rice. The results provide a reference for the structural optimization and performance improvement of the planter of the light and simple rice bowl seedling raising machine.

Key words: hybrid rice, precision sowing, seed protection components, seed cleaning area, damage index

摘要： 为进一步提高杂交稻钵苗育秧的播种精度，针对原设计的智能双充种型孔滚筒杂交稻育秧精密播种器作业过程中存在两次充种后重播指数偏高、种子破碎指数高和每穴播种粒数不均等问题，增加二次清种区，改进播种器的护种部件结构，改进后的播种器依靠双充种机构完成滚筒型孔充种，通过2次清种、护种及强制对穴投种的措施，提高每穴1~3粒的播种精度。试制改进后的原理样机，以特优2068催芽稻种为试验材料，采用三因素三水平正交试验方法，研究生产率、清种轮安装间隙和护种部件入口开度对播种合格指数、重播指数和种子破损指数的影响规律。试验表明影响播种合格指数与重播指数的因素主次顺序为生产率、清种轮安装间隙、护种部件入口开度；影响种子破损指数的因素主次顺序为生产率、护种部件入口开度、清种轮安装间隙。在生产率为400盘/h，清种轮安装间隙为2 mm、护种部件入口开度为3 mm的较优参数组合下，改进前后播种器对三轴尺寸相近的特优2068和五优1179及有一定差异的恒丰优1179稻种进行播种性能对比试验。结果表明尺寸相近的特优2068和五优1179，播种合格指数分别达到94.8%和94.6%，较改进前分别提高2.6%和2.9%，重播指数分别降低1.7%和2.2%，种子破损指数分别降低2.9%和3.6%，试验指标满足杂交稻低播量精密播种技术要求。研究结果为轻简型水稻钵苗育秧机播种器结构优化与性能提高提供参考。

关键词: 杂交稻, 精密播种, 护种部件, 清种区, 破损指数