Authors

Abstract

To address the deterioration in the seed-metering performance of mechanical seed-metering devices caused by vibration during field operation, a conical deflector-type seed meter was selected as the research object. A vibration-system model of the seed meter under field operating conditions was established, and the principal operating parameters affecting seed-metering performance were determined. The seed-metering process under vibration was then simulated using the discrete element method to investigate changes in the working angle of the seed population and its dynamic characteristics. In addition, vibration bench tests were conducted to evaluate the effects of vibration on seed-metering performance. The main results were as follows: (1) seed-filling efficiency, seed-clearing efficiency, and horizontal seed-throwing displacement were significantly affected by operating speed, vibration acceleration, and vibration frequency; (2) the adverse effect of vibration on seed-metering performance increased with increasing vibration acceleration but decreased with increasing operating speed or vibration frequency; and (3) when the vibration acceleration was below 0.63 g and the vibration frequency exceeded 4.28 Hz, the qualified-seed rate was greater than 95%, and the coefficient of variation of seed spacing was less than 20%. This study clarified the effects of vibration parameters on seed-metering performance and identified appropriate operating ranges, thereby providing theoretical support for the vibration-resistant design and optimization of mechanical seed meters.

Abstract in Chinese

针对机械式排种器在田间作业过程中易受振动影响导致排种性能下降的问题，选取锥面导流式排种器为研究对象，建立了排种器田间作业振动系统模型，推导出对排种性能产生影响的主要工况参数。运用离散元法对排种器振动工况下工作过程进行仿真试验，研究种群工作角度和动力学特性的变化规律，并通过振动台架试验测试了排种性能受到的影响。结果表明：1）排种器的充、清种效率及水平方向投种位移均受到作业速度、振动加速度和振动频率的显著影响；2）排种性能受到的负面影响随振动加速度的提升而增大，随作业速度和振动频率的提升而减小；3）当振动加速度小于0.63g，振动频率大于4.28Hz时，排种器的合格率高于95%，粒距均匀性变异系数低于20%。研究阐明了振动参数对排种性能的影响规律及其合理范围，为机械式排种器的抗振设计改进提供了理论支撑。