摘要
为有效解决型孔轮式排种器用于油菜排种时难以精确控制播量,清种、护种环节易剪切破坏种子的问题,采用气流清种与气压护种组合作用技术,设计了一种具有“倒方锥”型孔的油菜精量气压式集排器。该文对气压式集排器的工作原理进行了阐述,确定了其主要结构参数,并建立了油菜籽在清种区和护种区的力学模型,以总排量稳定性变异系数、各行排量一致性变异系数以及种子破损率为评价指标,以清种压差、护种压差及排种滚筒转速为试验因素在室内台架与田间条件下开展了排种性能试验研究,试验结果表明设计的集排器排种性能较优、种子破损率低,在清种压差250 Pa、护种压差150 Pa、排种滚筒转速以20-40 r/min时,其总排量稳定性变异系数≤2%：各行排量一致性变异系数≤2%;种子破损率〈0.3%。田间试验结果表明该集排器播种性能良好,满足油菜种植农艺要求。该研究证明采用气流清种与气压护种组合技术的“倒方锥”型孔油菜精量气压式集排器可用于小粒径、易破损种子的精量播种,为型孔轮式集排器结构改进与优化提供了依据。
To improve mechanical direct seeding level, a kind of precision centralized metering device for rapeseed with a reliable performance was designed, applying for high speed and broad width. The wheel type metering device with holes had a simple structure, low rape seeds of uniform granularity, and good spherical degree which could be better utilized, thus easily realizing a centralized seeding operation; otherwise, it had a high damage rate, and therefore thus would affect seeding performance. To solve the problem of the wheel type metering device with holes because of the difficulty of precisely controlling the seeding rate on rape seeding, the seeding type holes were punched in a pyramidal shape. The device used a combination of air clearing seed and air pressure protecting seed, so the device was a kind of pneumatic-typed precision centralized metering device for rapeseed. This subject introduced the working principle of a pneumatic-typed centralized metering device. It determined the main parameters of the centralized metering device, and established the mechanical model of clearing an area and protecting an area. The tests on the influences of clearing pressure and protecting pressure and seeding metering rotating speed were carried out. For seeding performance, the evaluation indexes were stability variability coefficient of the full seeding quantity, the apiece row consistency, variability coefficient of seeding quantity, and damage rate of the rapeseed. Results showed that under the condition that the seeding cylinder diameter was 100 mm, the hole shape was punched in a pyramid shape, the number of holes were 27, while the clearing pressure was 250 Pa, the protecting pressure was 150 Pa, the seed layer thickness was 49.4 mm, the clearing seed angle was 53~, and the protecting seed angle was 90~, the rotating speed varied from 20 to 70 r/min. The whole index and damage rate increased with the rise of the rotating speed of the cylinder. When the speed was not more than 40 r/min, the index changed into good range and had not much variation. When it was from 40 to 50 r/min, the damage rate of the rapeseed rarely changed, while the stability of the full seeding quantity and the apiece row consistency of seeding quantity obviously had a rising trend. If was no less than 50 r/min, the seeding performance was obviously getting worse. Thus, a seeding cylinder speed of 20-40 r/min was much better. For the stability variability coefficient of the full seeding, quantity was less than 2%. The apiece row consistency variability coefficient of seeding quantity was not more than 2%, and the damage rate was less than 0.3%. The field experiment showed that in conditions of clearing pressure 100 Pa, protecting pressure 300 Pa and seeding roller speed 26 r/min, the rape seed field seeding uniformity coefficient variation of the collecting seeding system was 38.76%, and the average emergence distance was 75 mm which satisfied agronomy planting requirements. This seeding method is suitable for small seed metering, and provides a basis for research on the design of this type metering device.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第7期9-17,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金资助项目(51275197
51405180)
国家油菜产业体系专项资助项目(CARS-13)
"十二五"国家科技支撑计划资助项目(2013BAD08B02)
中央高校基本科研业务费资助项目(2014PY033)
武汉市高新技术产业科技创新团队(2014070504020240)
关键词
农业机械
设计
种子
精量直播
集排器
气压式
护种
清种
油菜
agricultural machinery
design
seed
direct seeding
centralized metering device
pneumatic-typed
protecting seed
clearing seed
rapeseed
