Authors

Abstract

In response to the current challenges in the harvesting process of hybrid rice, where the threshing gap cannot adequately adapt to the varying threshing requirements, leading to high grain breakage rates, loss rates, and frequent clogging of the drum, a new threshing device for hybrid rice was designed by adjusting the gap of the concave screen. The concave screen was divided into a low-loss threshing section and a low-damage threshing section, with the addition of a hydraulic system to enable the adjustment of the threshing gap. A dynamic analysis of the rice at the spiral feeding inlet and within the threshing drum was conducted, determining that the adjustable range of the threshing gap is between 10 and 20 mm. A prototype of the low-loss threshing device for hybrid rice was built, and bench tests were performed with feed rate, drum speed, and threshing gap as influencing factors, while cleaning rate and breakage rate were used as response indicators in an orthogonal experiment to determine the optimal parameter combination. The optimal threshing performance was achieved at a threshing gap of 14.19 mm, a drum speed of 460.12 r/min, and a feed rate of 2.13 kg/s, resulting in a cleaning rate of 97.67% and a breakage rate of 0.295%. Subsequent verification tests under the optimal combination showed a cleaning rate of 96.2% and a breakage rate of 0.36%, meeting the harvesting standards for hybrid rice. This research provides theoretical support for the development of mechanized harvesting equipment for hybrid rice.

Abstract in Chinese

针对目前制繁种水稻收获过程中脱粒间隙无法很好的适应不同条件下水稻脱粒需求，脱粒过程中水稻籽粒破碎率、损失率及滚筒易堵塞等问题，从调节凹板筛脱粒间隙的角度出发，设计了一种制繁种水稻脱粒装置。将凹板筛设计为低损失脱粒段与低损伤脱粒段，通过加入液压系统能够实现脱粒间隙调节。对水稻在螺旋喂入口和脱粒滚筒内进行动力学分析，确定了脱粒间隙可调范围为10～20mm。试制了制繁种水稻低损脱粒装置试验台，进行台架试验，以喂入量、滚筒转速、脱粒间隙作为影响因素，以脱净率和破损率作为响应指标进行正交实验，确定最优组合参数，获得脱粒装置在脱粒间隙14.19mm、滚筒转速460.12r/min、喂入量2.13kg/s的组合参数下脱粒效果最优，脱净率为97.67%，破损率为0.295%，并在最优组合下验证试验，结果表明脱净率为96.2%，破损率为0.36%，满足水稻制繁种收获标准，该研究可为制繁种水稻机械化收获装备的研制提供理论支持。