大豆高速播种机侧置导引式精量排种器设计与试验

Design and Experiment of Side-mounted Guided High Speed Precision Seed Metering Device for Soybean

针对机械式排种器在高速作业条件下充种效果差,递种过程不稳定导致排种器合格指数低的问题,基于引导充种、缩短递种距离设计思想,设计了大豆高速播种机侧置导引式精量排种器,利用侧置型孔结构和导引板实现有序充种、稳定可靠递种。对充种、清种及递种过程进行了理论分析,建立了充填力模型,确定了影响排种器性能的关键参数为:充种倾角α、开口角β;确定了型孔的主要结构参数,并以合格指数、漏播指数为评价指标,采用二因素五水平中心旋转组合试验方法,对充种倾角α、开口角β开展仿真试验。结果表明:切向充填力随位置角的增大先增加后下降,z向充填力逐渐增大到最大值;充种倾角α、开口角β对合格指数、漏播指数影响极显著,得到结构参数的最优组合为:充种倾角α为11.50°、开口角β为119.05°;台架试验结果表明,在作业速度4~14 km/h下,侧置导引式大豆排种器合格指数不低于95.27%,漏播指数不大于4.73%,破损指数低于0.53%,满足高速精密播种要求。

Aiming at the problems of poor seed filling effect of mechanical seed metering device in high-speed operation and low qualification index of seed metering device caused by unstable seed delivery process,based on the design idea of guiding seed filling and shortening seed delivery distance,a side-guided soybean high-speed precision seed metering device was researched and designed,which realized orderly seed filling,stable and reliable seed delivery by using side-shaped hole structure and guide plate.The process of seed filling,seed cleaning and seed delivery was analyzed theoretically,and the filling force model was established.The key parameters affecting the performance of seed metering device were determined as follows:seed filling inclination angleα,opening angleβ;the main structural parameters of the shaped hole were determined,and the qualified index and the missed sowing index were used as evaluation indexes.The simulation test of the seed filling inclination angleαand the opening angleβwas carried out by using the combination test method of two factors and five levels of center rotation.The results showed that the tangential filling force reached the maximum value and then decreased with the increase of position angle,while the z filling force was gradually increased to the maximum value.Seed-filling angleαand opening angleβhad significant effects on qualified index and missed sowing index.The optimal combination of structural parameters obtained by optimization was that the seed-filling angleαwas 11.50°and the opening angleβwas 119.05°.The bench test results showed that at operating speed of 4~14 km/h,the qualified index of the side-guided soybean seed metering device was no less than 95.27%,the missed seeding index was no more than 4.73%,and the damage index was lower than 0.53%,which met the requirements of high-speed precision seeding.