油麦玉兼用精量联合直播机旋压灭茬整理装置设计与试验

Design and Test of Rotary Stubble-cutting and Seedbed Preparation Device for Multi-crop Combined Precision Seeder

摘要:

针对我国南方地区土壤黏重且留茬量大,机械化播种作业触土部件粘土缠茬降低开沟稳定性、种沟残留秸秆影响作物出苗一致性问题,设计一种具有厢面旋压整型、旋转切茬开种沟、覆土镇压功能的多作物兼用种床整理装置并研发配套播种机,实现一机兼用油麦玉播种。阐述兼用播种机设计方案,开展切茬开沟刀与秸秆互作过程力学分析,确定种床整理装置和4种圆盘切茬刀的结构尺寸和运动参数;进行主动圆盘切茬刀和滑刀式开沟器切茬过程离散元仿真,得到阿基米德螺线圆盘切茬刀转速为301.18r/min、滑刀式开沟器宽度为31.49mm时切茬效果较优;开展台架验证试验,结果表明台架试验与仿真试验秸秆切断率和土壤扰动面积相对误差小于10% ,仿真试验可靠;田间试验表明在黏重土壤稻茬地工况下油麦玉兼用播种机作业后厢面平整度为15.68mm,种沟秸秆切断率为93.7% ,油菜、小麦、玉米平均沟深分别为13.2、30.4、52.2 mm,沟深稳定性系数分别为90.6%、86.4%、88.2% ,满足油麦玉播种农艺要求。

Abstract:

Aiming to address the challenges associated with heavy clay soil, high stubble retention, insufficient stability in furrowing depth, and stubble interference with seedling emergence in Southern China, a seedbed preparation device integrating rotary pressing for ridge formation, stubble cutting, furrowing, soil covering, and compaction was developed. Accordingly, a compatible multi-purpose planter was designed to achieve combined sowing of rapeseed, wheat, and corn in wet fields with stubble retention. The overall design scheme of the planter was elaborated, featuring an active rotary pressing seedbed preparation device. Through an analysis of the interaction mechanism between the components and stubble, as well as the optimization of critical component designs, the configuration of the ridge-forming and furrowing device was determined, along with the structural dimensions and kinematic parameters of four types of disc coulters. Discrete element method (DEM) simulations were conducted to model the stubble cutting process under the combined action of an active disc coulter and a runner-type opener. The results indicated that the optimal cutting performance was achieved with an Archimedean spiral disc rotating at 301. 18 r/ min and a runner-type opener width of 31.49 mm. Bench tests were subsequently constructed and executed; the relative error for both the stubble cutting rate and soil disturbance area between the bench tests and simulation results was less than 10% , confirming the reliability of the simulation model. Field performance and sowing trials demonstrated that, under heavy clay soil conditions with stubble retention, the multi-purpose planter achieved a ridge surface flatness of 15.68 mm and a seed furrow stubble cutting rate of 93.7%. The sowing depths for rapeseed, wheat, and corn were 13.2mm, 30.4mm, and 52.2mm, with depth stability coefficients of 90.6%, 86.4%, and 88.2%, respectively. These performance metrics satisfied the agronomic requirements for the cultivation of rapeseed, wheat, and corn. The research result can provide a valuable reference for the design of multi-purpose planters in the rapeseed-wheat-corn planting regions of the middle and lower reaches of the Yangtze River.