凸包异形孔窝眼轮式人参精密排种器设计与试验

Design and Test of Ginseng Precision Special-hole Type Seed-metering Device with Convex Hull

针对人参种子流动性差,导致排种器在充种环节漏充严重、伤种率高等问题,采用增大种群扰动、减小局部种间摩擦力的方法,提高排种器的充种性能,并基于此设计了一种凸包异形孔窝眼轮式精密排种器。通过对充种区种子受力状态和运动状态进行分析,阐明了凸包异形孔结构提高排种器充种性能的机理;进行理论计算和对充种过程运动学分析,利用EDEM软件进行了单因素仿真试验,分析了不同结构参数对种群的影响,并确定了窝眼轮的结构参数;以窝眼轮转速、凸包高径比和种层高度为试验因素,以合格指数、重播指数和漏播指数为试验指标,进行了二次回归正交旋转组合试验。试验结果表明:影响合格指数的主次顺序依次为凸包高径比、窝眼轮转速、种层高度;当窝眼轮转速为29.75 r/min、凸包高径比为0.43、种层高度为53.92 mm时,充种性能最佳,此时合格指数为95.59%、重播指数为2.97%、漏播指数为1.40%。为验证排种器的工作性能,进行了台架试验和田间试验,结果表明,凸包异形孔窝眼轮式精密排种器的充种性能较好,满足人参播种要求。

In order to solve the problem of the poor fluidity of ginseng seeds caused seed-metering device the serious shortage of filling-seed and the easy damage of seeds.The method of enlarging seeds disturbance and reducing local seeds friction was adopted to improve the filling-seed performance of seed-metering device.And based on this a precision special-hole type seed-metering device with convex hull was designed.Through the analysis of the force and motion state of seeds in the filling-seed area,the mechanism of convex hull and special-hole improving filling-seed performance of seed-metering device was expounded.And through the calculation of the kinematic analysis of theoretical calculation to filling-seed process,the single factor simulation test was conducted through the EDEM,the influence of different structural parameters on seeds was analyzed and the structural parameters of special-hole were ascertained.Then the quadratic regression orthogonal rotation combination test was done,with the rotation rate of special-hole,height diameter ratio of convex hull and seed’s height as the test factors,and the qualified index,the multiple index and the missing index as the test index.Experimental results showed that the primary and secondary order of influencing conformity index was height diameter ratio of convex hull,the rotation rate of special-hole and seed’s height.When the rotation rate of special-hole was 29.75 r/min,height diameter ratio of convex hull was 0.43 and seed’s height was 53.92 mm,filling-seed performance was the optimum,the qualified index was 95.59%,the multiple index was 2.97%and the missing index was 1.40%.The bench test and field experiment were conducted to testify the working performance of seed-metering device,which showed that the precision special-hole type seed-metering device with convex hull had the filling-seed better performance and can meet the requirements of ginseng sow.