Authors

Abstract

The performance of hole-type metering device influenced the adaption of different rice varieties in the mechanical direct hill-drop seeding technology, and the stepless adjustable sowing amount hole-type metering wheel was designed to solve this problem. The mechanical characteristics of different seeds were analyzed to acquire the parameters including hole diameter, depth, number, diameter of metering wheel and jogger slider mechanism, and the performance of metering wheel was tested on JPS-12 experimental bench by using Yongyou 12, Huanghuazhan and Wanxiang youhuazhan varieties. The hole depth and rotating speeds of metering wheel were the independence variance, the average seed numbers per hole, the coefficient of variance and the cavity rate were taken as the evaluation indexes. The results showed that the metering wheel could sow 3.58~7.82 seeds per hole with less than 40% of the coefficient of variance in average seeds number per hole and less than 5% of the cavity rate, and the regression model of average seed numbers per hole was built by employing the length of seeds, the rotating speed of metering wheel and the hole depth. The correlation coefficient was 0.952, the prediction error of regression mode was 0.32~11.35% by the field experiment. This study could be used for designing the hole-type metering device for rice.

Abstract in Chinese

为提高型孔式水稻穴直播排种器对不同粒型稻种的适应性及播量调节范围，本文基于型孔深度可调的技术思路，设计了一种水稻播量无级可调型孔式排种轮；研究了不同稻种粒形尺寸特征，确定了型孔直径、型孔深度、型孔数量、排种轮直径、深度调节顶杆滑块机构等关键部件的结构参数；并以破胸露白稻种甬优12、黄华占和万象优华占为供试品种，以排种轮转速和型孔深度为试验因素，以穴粒数变异系数和空穴率为评价指标，开展了全因素台架试验，结果表明，就3种不同粒型供试品种而言，排种轮在型孔深度3~8 mm和排种轮转速10~90 r/min的不同组合条件下，且满足平均穴粒数变异系数小于40%和空穴率小于5%，可实现平均穴粒数3.58~7.82粒/穴可调播种；同时，采用逐步回归法，建立了以稻种长度、排种轮转速和型孔深度为自变量的排种轮平均穴粒数回归模型，相关系数为0.952，进而通过田间试验验证了模型准确性，模型预测误差为0.32~11.35%。本文研究结果可为型孔式水稻穴直播排种器开发提供关键部件。