摘要
为研究水稻气力式排种器的稻种在送种正压作用下脱离排种盘后的轨迹以及投种成穴性,该文采用高速摄影技术分析了投种轨迹的变化规律及其影响因素,并对投种后的穴径进行了测量通过实际投种轨迹的均值优化理论方程,得到了不同条件下的优化方程。以＂培杂泰丰＂超级杂交稻种子为研究对象,采用多因素试验方法,分析了不同转速、不同送种正压下,稻种投影面正面与侧面轨迹与投种穴径的变化。试验结果表明：正面投种轨迹随排种盘转速的提高其水平位移增大,但整体偏移均小于5mm。当送种正压为0.1kPa时,其落种轨迹的稳定性较好,投种正面水平位移基本稳定在45~65mm,当送种正压为0.2kPa时,投种轨迹分布不均,稳定性较差;侧面投种轨迹受排种盘转速影响较小,增大送种正压会增大稻种侧面的水平位移,当送种正压为0.1kPa时,其投种侧面水平位移稳定分布在0~15mm,当送种正压为0.2kPa时,投种轨迹分布波动较大;穴径随转速与送种正压的提升,其大于50mm的概率也增多,排种盘转速为30r/min、送种正压为0.1kPa时,成穴性最好,其合格率为96.9%。投种高度控制在离地面10cm左右为最佳。该文从理论的角度分析了投种轨迹,得到了成穴性最优的条件,为水稻气力式排种器最优成穴条件与排种管的设计提供参考。
Compared to rice mechanistic metering device,rice pneumatic metering device has advantages of low number of sowing seeds,high precision of seed metering and low seed-injuring rate.Because the precision of seed metering is difficult to control and the performance of hill sowing is poor,rice pneumatic metering device is difficult to be widely used in field direct-seeding.The control of the precision of seed metering is the key to design metering device.Analysis of the process of dropping seeds helps improve the precision of seed metering and the performance of hill sowing,providing a basis for the design of metering device.Seeds were taken away from sowing disc under positive pressure for blowing seeds.The dropping trajectories and hill sowing performance of rice seeds were studied in this article.A high-speed photography technology was introduced to investigate how the dropping trajectories of rice seeds varied and what influenced the dropping trajectories,on which the equations of the rice＇s movement were formed.The theory equations were optimized through the average horizontal displacements of actual dropping trajectories and the optimization equations under the different conditions were obtained.The diameter of hill sowing was also measured.As seeds were taken away from sowing disc under positive pressure,seeds gained an initial velocity,which was called Vz and was vertical to the sowing disc.Because seeds moved along with sowing disc rotating before seeds were blown away,the seeds gained the other initial velocity,which was called Vr and was parallel to the disc.Seeds also gained acceleration of gravity under the gravity.In the above factors,the dropping trajectories were spatial parabolic,which was more complicated than the plane parabolic trajectories of rice mechanistic metering device.In order to investigate and count the dropping trajectories of rice pneumatic metering device,a coordinate system was established.Indic hybrid Peizataifeng was taken as research subject in this article,of which water content and average length,width and thickness were 20.5% and 8.97,2.34 and 1.90 mm respectively.There were 2 dropping trajectories,the trajectory of frontal dropping seed and the trajectory of profile dropping seed.The dropping trajectories and diameters of hill sowing were analyzed by multi-factor experiment under different rotation rates and positive pressures for blowing seeds.The experimental results showed horizontal displacements of the trajectory of frontal dropping seed increased with the increasing of rotation rate,which were less than 5 mm.The frontal trajectory had good stability under positive pressure of 0.1kPa,and horizontal displacements were stabilized within the range of 45-65 mm.Under positive pressure of 0.2 kP a,the frontal trajectory was unevenly distributed with bad stability.Trajectory of profile dropping seed was little affected by rotation rate.Horizontal displacements of trajectory of profile dropping seed increased with the increasing of positive pressure for blowing seeds.The profile trajectories were stabilized within the range of 0-15 mm under positive pressure of 0.1kPa.Under positive pressure of 0.2kPa,the profile trajectories were unevenly distributed.Diameters of the hill less than 50 mm were deemed as qualified,while diameters more than 50 mm were deemed as substandard.The probability of substandard diameter increased with the increased rotation rate and positive pressure.Performance of hill sowing was best with the rotating speed of 30 r/min and positive pressure of 0.1kPa,of which qualified rate was 96.9%.The optimum height of dropping seeds was 10 cm.This article analyzed dropping trajectories in theory and got the optimal conditions of performance of hill sowing,providing the basis for optimal conditions of hill sowing and the reference for the design of seeding tubes of rice pneumatic metering device.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第12期23-30,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
863高新计划项目(2012AA10A501-2)
公益性行业项目(201203059)
国家自然科学基金项目(51105147)
广东省自然科学基金项目(S2011010001948)
关键词
农业机械
种子
气力式设备
水稻
气力式排种器
落种轨迹
成穴性
高速摄影
agricultural machinery
seed
pneumatic equipment
rice
pneumatic metering device
dropping trajectories
hill sowing
high speed photography
