偏心弹射式排肥器设计与仿真试验

Design and simulation test of an eccentric ejection fertilizer apparatus

针对目前穴施排肥器存在易伤作物、喷肥均匀性差、喷肥可靠性低等问题,设计一种偏心弹射式排肥器。根据颗粒肥穴施特性,基于盛肥腔体积压缩而形成压力差的原理,借助人机交互平台,设计关键部件弹射机构和偏心机构,优化机构的结构与工作参数,分析肥料在腔体内的受力状况和运动轨迹。该排肥器主要由排肥装置、偏心轮装置、弹射部件等组成。通过Soildworks三维建模,运用离散元法(EDEM)和动力学(RecurDyn)耦合仿真分析技术对排肥器的成穴性进行仿真,并进行台架试验。试验表明:该机构弹射性能稳定可靠,对农作物无机械损伤。在排肥器角速度为6.2 rad/s、6.7 rad/s,7.2 rad/s时,每穴排肥量一致性变异系数分别为2.8%、3.3%、4.0%,肥料喷射均匀性较好。作业效率等各项指标与预期目标差异性小。离散元仿真值与台架试验相对误差值接近,表明台架试验结果真实可靠。

In view of the problems of the current hole fertilizer apparatus,such as easy to damage crops,poor fertilizer spraying uniformity,and low reliability of fertilizer spraying,an eccentric ejection fertilizer apparatus was designed.According to the characteristics of the granular fertilizer hole application,based on the principle that the volume compression of the fertilizer chamber can form a pressure difference,through a human-computer interaction platform,the key components of the ejection mechanism and the eccentric mechanism were designed,the structure and operating parameters of the mechanism were optimized,and the force status and movement trajectory of the fertilizer in the chamber was analyzed.This fertilizer apparatus is mainly composed of a discharging device,an eccentric wheel device,and ejection components.Through Soildworks 3D modeling,and using Extended Distinct Element Method(EDEM)and RecurDyn dynamics coupled simulation analysis technology,it simulated the cavitation of the fertilizer apparatus,and conducted a bench test.The test indicated that the mechanism s ejection performance was stable and reliable,and caused no mechanical damage to crops.When the angular velocity of the fertilizer apparatus was 6.2 rad/s,6.7 rad/s,and 7.2 rad/s,the variable coefficient of the consistency of fertilizer discharge per hole was 2.8%,3.3%,4.0%,respectively,and the uniformity of fertilizer spraying performed good.There was little difference between the various indicators such as work efficiency and the anticipated goals.The discrete element simulation value was close to the relative error value of the bench test,and the discrete element simulation result was convinced to be reliable.