种腔自净型气吸式玉米小区精量排种器设计与试验

Design and Experiment of Air-suction Precision Seed Meter with Self-clearing Seed Chamber for Corn Plot Test

为满足玉米育种试验的播种需要,设计了一种种腔自净型气吸式精量排种器,该排种器的充种腔与清种腔相互独立,排种与清种过程互不干扰,自净率达100%。通过考察育种试验用种子的形状,并结合育种试验的特点,确定了排种器关键结构参数。对种子吸附的过程进行动力学分析,并利用EDEM软件仿真验证了种量较少时搅种盘的种群扰动作用。利用Fluent软件模拟验证了当剩余种子不超过10粒、清种时间不超过1s的情况下,清种真空度大于3kPa时,可保证剩余种子全部清出。对育种试验用种子进行分级处理,在真空度3~4kPa范围内进行单因素试验,结果表明,清种阶段已吸附在吸孔上的任一规格种子均能正常播种。排种器台架试验结果显示,播种机作业速度小于3.6km/h,真空度6~8kPa,刮种板工作面距离吸孔中心2~4mm范围内时,排种器的漏播率小于1%,重播率小于4%,合格指数大于95%,各项指标符合国家标准要求,能实现有效排种,同时保证清种率达到100%。排种器田间试验证明,出苗效果符合育种试验的播种要求。

In order to meet the needs of corn breeding test,an air-suction precision seed meter with selfclearing seed chamber was designed,whose seed chamber and seed clearing chamber were independent of each other. The process of metering and clearing did not interfere with each other. The self-purification rate could achieve 100%. The shape of breeding seeds was analyzed,and the key structural parameters of seed meter were determined according to the characteristics of breeding experiment. Dynamics analysis of the process of seed adsorption was carried out,and EDEM software was used to verify the disturbance of churn plate to the fewer population. Fluent software was used to simulate the seed clearing process. It was proved that when the remaining seeds were not more than 10 and the clearing time was not more than1 s,the vacuum of clearing seeds was greater than 3 kPa,the remaining seeds could be cleared completely. Seeds used in breeding experiments were graded,single factor experiments were carried out in the vacuum range of 3 ~ 4 kPa. The results showed that seeds adsorbed on suction holes in the clearing stage could still be sown normally regardless of their specifications. Experiments of the normal seeding stage were carried out on the JPS-12 test bench. When the vacuum was between 6 kPa and 8 kPa,the operation speed of the seeder was less than 3. 6 km/h,and the working face of the scraper was within 2 ~4 mm from the suction hole center,the qualified index of seed spacing exceeded 95%,the missingseeding rate and the reseeding rate were less than 1% and 4%,respectively. Each index met the national standard. The performance of seed metering device was effective while the clearance rate could reach 100%. The field experiment of seeder proved that the seedling emergence effect met the seeding requirement of breeding experiment.