摘要
为实现三七种子的精量播种,针对三七种子形状不规则、含水率较高易造成种子流动性差和不易充种的问题,设计了一种滚轮圆刷式三七精密排种器,阐述了其基本结构和工作原理,分析了型孔的形状和大小对充种的影响;为实现零速投种,对护种板安装角度进行了分析;研究了充种区种子的受力情况,建立了圆刷滚轮接触区内三七种子运动方程.对圆刷滚轮接触区内三七种子的运动情况进行了仿真分析,其结果与理论计算值基本一致.选取型孔轮转速、型孔直径和型孔深度为试验因子,以粒距合格指数、重播指数和漏播指数为评价指标,采用3因子3水平正交设计方法进行排种器台架试验.结果表明:型孔轮转速20r/min、型孔深度7mm、型孔直径8.5mm为较优组合,此时的粒距合格指数可以达到93.17%,重播指数为3.40%,漏播指数为3.43%,达到了三七种子精密播种的要求.
Summary Panax notoginseng is a well-known Chinese herbal medicine and is manually sown because of no supporting device for precise seed metering. Seed-metering device was an essential part for the sower of P. notoginseng, and its efficiency has significant impact on the quality of sowing. The direction of design on mechanical precise seed-metering device is toward high efficiency and automation. The purpose of this study was to solve the problem of poor fluidity for P. notoginseng seed caused by irregular shape and high water content and to achieve precise seeding for P. notoginseng. A novel type of roller- round brush precise seed-metering device was designed for P. notoginseng, and the optimal metering parameters on the performance of the machine were explored. In this study, basic structure and working principle of the model were described, and the effect of shape and size of the type hole on seed-filling was analyzed. The angle for shield plate installation was analyzed to achieve zero-speed dropping. Simulation was utilized to analyze the motion of P. notoginseng seeds in the seed-filling zone, and a motion equation was established in the roller-round brush contact zone. The speed, diameter and depth of the type hole were selected as the three test factors for the precise seed-metering device. The simulation model of the seed-metering device for P. notoginseng seeds was established by the UGNX software, and was conducted on the basis of the EDEM dynamic simulation software. Through theoretical calculation, it was determined that the diameter of the type hole was in the range of 8 - 9 ram, and the depth of the type hole was in the range of 6 - 7 mm. For the zero speed seeding, the installation angle of the shield plate was related to the speed of the metering device and the wheel speed of the type hole. The change o[ the movement for P. notoginseng seeds was consistent with the direction of the motion analysis. The movement of the seeds in the contact zone of the roller-round brush was verified. Further experiments were conducted to increase the qualified index of seed space, and reduce the multi-seeding and miss-seeding indexes, lower the intensity of field test. The results showed that the optimal condition was the speed of the type hole wheel of 20 r/min, with the type hole diameter of 8.5 mm and the type hole depth of 7 ram. Under the optimal condition, the qualified index of the seed space was 93.17 %, the multi-seeding and the miss-seeding indexes were 3.40% and 3.43%, respectively. In conclusion, the seed-metering device is a key component of seeding machine, and the simulation analysis for the roller-round brush seed-metering device can meet the requirement of precise seeding for P. notoginseng, providing a methodological reference for optimizing precision metering for other types of seeds.
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2016年第4期509-516,共8页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
国家自然科学基金(51305187)
云南省重点新产品计划项目(2014BC007)
昆明理工大学自然科学研究基金(KKSY201323067
KKSY201323025)
关键词
排种器
三七种子
仿真分析
seed-metering device
Panax notoginseng seed
simulation analysi
