Authors

Abstract

The paper, combined with structural characteristics of mechanical seed metering devices and air-suction seed metering devices, designs a multi-mode seed metering device. According to installation of seed holding rings and application of negative pressure, three modes (mechanical mode, air-suction mode and combination of air-suction mode and mechanical mode) can be realized. JPS-12 seed metering performance test benches and high-speed camera are used for indoor tests. According to results, under the mechanical mode, advancing speed has a significant effect on seed metering performance. At a low speed, the qualification rate is maintained at about 96%; with advancing speed increased, the qualification rate decreases significantly. Seed spacing variation coefficient gradually increases with speed increased and stabilizes at about 30%. Under the air suction mode, negative pressure and advancing speed have a significant effect on qualification rate and miss seeding rate. With negative pressure increased, qualification rate increases while miss seeding rate decreases. Negative pressure has no significant effect on seed spacing variation coefficient, but advancing speed has a significant effect on seed spacing variation coefficient. With speed increased, seed spacing variation coefficient increases significantly. Under the multi-mode, advancing speed and negative pressure have a significant effect on qualification rate and miss seeding rate. Negative pressure has no significant effect on seed spacing variation coefficient, but advancing speed has a significant effect on seed spacing variation coefficient. Upon comparison of three modes, when speed is 6 km/h, qualification rate of air suction mode is close to multi-mode, which is significantly higher than that of mechanical mode. When speed is 8-12 km/h, qualification rate of multi-mode is significantly higher than that of air suction work. With negative pressure increased, gap between them gradually decreases.

Abstract in Chinese

本文结合机械式排种器和气吸式排种器的结构特点，设计一种多模式排种器，根据是否安装护种环，以及是否施加负压，可实现机械、气吸和气吸-机械复合三种作业模式。利用JPS-12排种性能试验台和高速摄像机进行室内试验。结果表明：机械作业模式下，前进速度对充种性能具有显著影响，在速度较小时，合格率维持在96%左右；随着前进速度的增加，合格率出现显著下降。粒距变异系数随着速度的增大，逐渐增加，并稳定在30%左右。气吸作业模式下，负压和前进速度对合格率与漏播率都具有显著影响。随着负压的增大，合格率增加，漏播率降低。负压对粒距变异系数影响不显著，然而前进速度对粒距变异系数影响显著，随着速度的增大，粒距变异系数出现显著提高。复合作业模式下，前进速度和负压对合格率与漏播率均具有显著影响。负压对粒距变异系数影响不显著，前进速度对粒距变异系数影响显著。对比三种作业模式，在6km/h时，气吸与复合作业模式的合格率接近，显著大于机械模式。在8-12km/h时，复合式作业的合格率显著大于气吸式作业，随着负压的增大，两者之间的差距逐渐减小。