小麦小区条播机离心分种器参数优化与试验

为了对离心分种器进行结构改进和参数优化以提高小麦小区播种机的分种均匀性，该文对小麦离心分种过程进行运动分析，得出小麦籽粒的运动受到离心分种器转速、分种面夹角和分种距离的影响；采用离散元仿真软件，建立仿真模型，以离心分种器转速、分种面夹角和分种距离为试验因素，以分种均匀性变异系数为试验指标，进行不同播量下的三因素三水平正交试验，研究各个因素对分种均匀性的影响规律，以获得较优的参数组合。仿真试验结果表明，在播量为2 000、3 000粒时影响分种均匀性的主次因素为离心分种器转速、分种距离和分种面夹角，在播量为1 000粒时为离心分种器转速、分种面夹角、分种距离；通过仿真试验和台架试验，确定离心分种器较优参数组合为离心分种器转速1 250 r/min、分种面夹角120°、分种距离17.5 mm，台架试验条件下3种播量的分种均匀性变异系数分别为5.18%、4.45%和3.98%，与仿真试验结果相差0.36%、0.14%和0.55%，两者基本一致，且籽粒破碎率为0.17%、0.13%和0.14%，具有较小的籽粒破碎。该研究可为小麦小区条播机的离心分种器优化改进以及分种性能提升提供参考。

Parameter optimization and experiment of centrifugal seed dispenser in wheat plot drill

Field breeding experiments are small area trials conducted in plots for breeding new crop varieties, which is important to improve crop quality and seed propagation. As a major part of field breeding experiment, plot sowing has a significant impact on the test results. The plot drill machine is a special sowing machine used for field breeding experiment, which can complete supplying, filling, shipping, seeding, and dispensing. Among them, the uniformity of sowing is directly effected by the performance of centrifugal seed dispenser. However, the research of seed dispenser is insufficient, such as the influence of structural parameters, rotational speed and sowing rate on the seeding uniformity, which cannot met the requirements of the breeders and still need to further improved. In order to improve the seeding uniformity of plot seeder, centrifugal seed dispenser was taken as the research object, and motion characteristic was analyzed in the process of centrifugal dispensing seed. According to the analysis of kinematic characteristics, the centrifugal movement of wheat granules was mainly affected by dispenser rotation speed, dispenser angle, and dispenser distance. In this research, the combination of EDEM and experimental verification were used to analyze the influence of various test factors on the uniformity of dispensing seed. When the sowing rate is 1 000, 2 000 and 3 000 seeds, the three-factor and three-level orthogonal test was designed with dispenser rotation speed, dispenser angle, and dispenser distance as test factors, and the variation coefficient of seeding uniformity was used as the test index, to obtain better combination of parameters. Among them, dispenser rotation speed was set at 1 100, 1 250 and 1 400 r/min, dispenser angle was selected 90, 120 and 150°, dispenser distance was choose 17.5, 22.5 and 27.5 mm. The simulation results showed that the order of importance was followed by dispenser rotation speed, dispenser distances and dispenser angle in the case of 2 000 seeds and 3 000 seeds. When the sowing rate was 1 000 seeds, the order of importance was followed by dispenser rotation speed, dispenser angle and dispenser distance. According to the analysis of variance, the dispenser rotation speed has a significant effect on the variation coefficient of seeding uniformity when the sowing rate was 1 000 and 2 000 seeds, and has some effect when the sowing rate was 3 000 seeds. The dispenser angle has a certain significant effect on the variation coefficient of seeding uniformity when the sowing rate was 1 000 and has no effect on other seeding rates. Dispenser distance has a certain effect on the variation coefficient of seeding uniformity when the sowing rate was 1 000 and 2 000 seeds, and has no effect when the sowing rate was 3 000 seeds. The test bench was set up. Under the optimal combination of parameters, test was repeated three times to get the main value of variation coefficient of seeding uniformity. The tests revealed that the better combination of parameters was that the dispenser rotation speed was 1 250 r/min, the dispenser angle was 120° and the dispenser distance was 17.5 mm. When the sowing rate was 1 000, 2 000 and 3 000 seeds, the variation coefficient of seeding uniformity of were 5.18%, 4.45% and 3.98%, respectively, which were 0.36%, 0.14% and 0.55% different from the simulation results, the bench test and simulation test results were basically the same. The grain damage rate were 0.17%, 0.13% and 0.14%, and the grain damage was lower, which reached the requirements of plot sowing. The research results could provide a reference for optimizing structural parameters and improving of seeding performance of centrifugal seed dispenser in plot drill.