玉米原茬地高速作业侧向清茬刀设计与试验

Design and Test of Lateral Stubble Clearing Blade for High-speed Operation in Corn Stubble Field

摘要:

针对我国东北地区玉米原茬地免耕播种机高速作业时，播种施肥触土部件堵塞导致播种作业质量降低等问题，改进设计一种适用于高速免少耕播种作业的侧向清茬刀。通过对正切刃折弯曲线及作业过程理论分析，确定了侧向清茬刀的结构和工作参数，构建了清茬防堵装置在田间作业过程中刀齿-土壤-根茬离散元仿真模型，进行了以清茬刀正切刃折弯角、作业速度和刀轴转速为影响因子，根茬清除率、土壤扰动率和当量功耗为评价指标的二次回归正交中心旋转组合仿真试验。依据参数优化仿真结果试制样机并进行田间性能试验，结果表明：在玉米残茬覆盖量1.73kg/m2、平均留茬高度400mm、土壤硬度20.8kg/cm2条件下，当正切刃折弯角34.5°、作业速度14.4km/h、刀轴转速380r/min时性能最优，此时根茬清除率91.6%、土壤扰动率26.6%、当量功耗12.62kW；安装优化清茬刀的清茬装置比安装侧向清秸刀齿的根茬清除率提高12.67%。

Abstract:

Aiming at the high speed operation of no-tillage seeder in corn stubble land in Northeast China, the clogging of seeding and fertilizer touching parts leads to the reduction of the quality of seeding operation, etc., the design of a lateral stubble clearing knife suitable for high speed no-tillage seeding operation was improved. Through the theoretical analysis of bending curve of tangent blade and operation process, the structure and working parameters of the lateral stubble knife were determined, and a discrete element simulation model of the blade-soil-root stubble was constructed for the stubble clearing and anti-clogging device in the field operation process, and the quadratic regression orthogonal center was carried out with the bending angle of the tangent blade of the stubble clearing knife, the operation speed and the knife shaft rotation speed as the influencing factors, and the stubble removal rate, the soil disturbing rate, and the equivalent power consumption as the evaluating indexes. Rotary combination simulation test was done. According to the simulation results of parameter optimization, the prototype was manufactured and field performance tests were conducted, and the results showed that under the conditions of corn stubble coverage of 1.73kg/m2, average stubble height of 400mm, and soil hardness of 20.8kg/cm2, the performance was optimal when the combination of parameter combinations of the bending angle of the cutting edge of 34.5°, the operating speed of 14.4km/h, and the cutter shaft rotational speed of 380r/min were combined. In this case, the root stubble removal rate was 91.6%, soil disturbance rate was 26.6%, and power consumption was 12.62kW; the stubble removal rate of the stubble removal device with optimized stubble removal knives was increased by 12.67% compared with that of the stubble removal device with lateral stubble removal knife blade.