摘要
针对中国一年两熟地区麦茬地免耕播种玉米时小麦秸秆易堵塞播种机造成漏播、晾籽等问题,提出一种圆辊拨爪式的防堵机构。通过离散元模拟仿真与土槽试验相结合的方式对圆辊拨爪式防堵机构的结构参数与工作参数进行分析,进而在田间验证其防堵性能。根据拨爪高度占整个防堵机构高度的百分比设计7种不同结构型式的防堵机构。离散元仿真分析表明2/3型、3/4型和1型防堵机构的秸秆清除率均在85%以上;进一步分析得出2/3型结构在任一设定转速和前进速度下的秸秆清除性能都是最佳;且较经济的机构工作参数为转速400r/min和5km/h。借助在土槽实验室搭建的高速摄像系统发现防堵机构作业过程中秸秆受力并随防堵机构运动时,秸秆在垂直方向上有层叠堆积,这在一定程度上缓解秸秆回填。土槽试验结果表明2/3型防堵机构的最佳工作参数为转速400r/min、前进速度5km/h,与仿真试验结论一致。田间试验再次验证拨爪高度占整个防堵机构高度2/3时的机构防堵性能最佳,且其与另一商品化防堵机构的对比结果,该防堵机构在机具通过性、晾籽率、出苗率、苗高及秸秆清除率方面表现较优。
Huang-Huai-Hai Plain of China belongs to semi-arid and semi-humid regions;it is part of the main grain production areas in China.The primary planting pattern of the area is winter wheat-summer maize rotation system and total yields of wheat and maize of the area accounts for 51.0% of those of the national yield.Adoption of crop residue cover can not only improve straw utilization ratio and decrease pollution,but also control soil erosion,increase soil organic matter level and improve crop yield.However,the field condition of straw residue cover challenges the maize seeding in Huang-Huai-Hai Plain,the effectiveness of residue management mechanisms used in direct seeding systems has a significant impact on furrow opening and closing,and the uniformity of seeding depth.Inadequate residue management results in blockage of furrow openers with accumulated residues and impaired seed-soil contact can be expected to result in poor germination,seedling emergence,crop establishment.So,an efficient anti-blocking mechanism becomes the core of seeding efficiency and seeding quality of maize planter.We put forward a kind of anti-blocking mechanism with round roller and claw,and seven types of anti-blocking mechanisms are designed according to the proportion of claw height accounted of total round roller-claw anti-blocking mechanism height,namely 0,1/4,1/3,1/2,2/3,3/4 and 1,respectively,to push residues sideways ahead of furrow opening,and their performances were evaluated via machine pass capacity,rate of apparent seed,mass of coiled straw,soil mound depth,height of seedling,rate of emergence and straw clearance rate through discrete element method simulation,high-speed photography soil bin experiment and field experiment.The discrete element method simulation showed that the straw clearance rates of 2/3 type,3/4 type and 1 type mechanisms all exceed 85%,and 2/3 type mechanism ranked the first while took rotational speed and forward speed of anti-blocking mechanism into account.The soil bin experiment pointed out the anti-mechanism decreased straw returning and the optimal working parameters of 2/3 type mechanism were rotation speed of 400 r/min and forward speed of 5 km/h.The seven anti-blocking types were again verified and being compared with one widely used anti-blocking mechanism in field experiment.There was no serious blockage happened during the process of seeding with various types of round roller-claw anti-blocking mechanism;apparent seed also did not find except the 1/4 round roller-claw anti-blocking mechanism with a rate of0.35%.The higher the claw was,the more easily coiled in straw.However,the height of claw had no significant effect on the mass of coiled straw while we took mass of coiled straw per unit height into consideration.The claw part can make soil loosen,but there was no correlation between the height of the claw and the soil mound depth from the ANOVA results.The height of seedling to a certain extent reflects the quality and quantity of seeding.It can be inferred that the 1/2 and higher round roller-claw anti-blocking mechanism could promote the growing of corn.Furthermore,the 2/3 type round roller-claw anti-blocking mechanism was recommended while the rate of emergence was considered at the same time.The straw clearance rate of 2/3 type could attain 86.7% while in straw mulch conditions.The comparison between 2/3 type mechanism and one widely used anti-blocking mechanism showed that the designed 2/3 type mechanism behaved better in no-tillage seeding.
作者
方会敏
史嵩
乔璐
牛萌萌
徐高伟
荐世春
Fang Huimin;Shi Song;Qiao Lu;Niu Mengmeng;Xu Gaowei;Jian Shichun(Shandong Academy of Agricultural machinery Sciences,Jinan,250100,China;Nanjing Research Institute for Agricultural Mechanization of National Ministry of Agriculture and Rural Affairs,Nanjing,210014,China)
出处
《中国农机化学报》
北大核心
2018年第12期1-9,共9页
Journal of Chinese Agricultural Mechanization
基金
山东省自然科学基金项目(ZR2018BEE021
ZR2016EEB22)
国家重点研发计划"粮食丰产增效科技创新"重点专项(2017YFD0301000)
关键词
圆辊拨爪
离散元
秸秆清除率
出苗率
苗高
round roller-claw
discrete element method
straw clearance rate
rate of emergence
height of seedling
