玉米条带少耕仿生清秸装置设计与试验

Design and Experiment of Bionic Straw-cleaning Device for Maize Strip Reduced Tillage

摘要:

针对东北黑土区春季玉米秸秆覆盖条件下,条带少耕作业中传统清秸圆盘清秸率偏低、秸秆横向抛掷能力不足等问题,以东北大黑鳃金龟后足跗节主爪为仿生原型,设计了一种玉米条带少耕仿生清秸装置。提取主爪轮廓曲线,建立仿生盘齿模型,并开展清秸圆盘参数设计与空间运动学分析。构建“仿生清秸圆盘-秸秆-土壤”离散元互作模型,以机具作业速度、前倾角和侧倾角为试验因素,以清秸率和秸秆横向最大抛掷距离为评价指标,开展单因素试验和三因素五水平二次回归正交旋转组合试验。结果表明,最优参数组合为机具作业速度7.13 km/h、前倾角27.73°、侧倾角14.05°,此时仿真预测清秸率为90.16%,秸秆横向最大抛掷距离为30.00 cm。对仿生清秸圆盘与普通缺口式清秸圆盘进行离散元仿真分析,结果表明,仿生清秸圆盘作用下秸秆高速度区域分布更连续,横向运动趋势更明显。台架试验结果表明,在取整后最优参数组合下,装置实测清秸率为89.38%,秸秆横向最大抛掷距离为27.52 cm;当秸秆覆盖量不高于1.5 kg/m2时,装置仍能满足清秸作业要求。田间试验结果表明,在作业速度6~8 km/h区间内,仿生清秸圆盘清秸率均不低于84.74%,较普通缺口式清秸圆盘最高提高5.99个百分点,相对提升7.61%;秸秆横向最大抛掷距离最高增加3.95 cm。研究结果表明,该装置能够改善东北黑土区春季玉米秸秆覆盖条件下的清秸效果和秸秆横向抛掷性能。

Abstract:

Aiming to address the low straw-cleaning rate and insufficient transverse straw-throwing capacity of conventional straw-cleaning discs under spring maize straw coverage in the black soil region of Northeast China, a bionic straw-cleaning device for maize strip reduced tillage was designed by using the hind tarsal main claw of Holotrichia diomphalia Bates as the bionic prototype. The claw contour was extracted to establish a bionic disc tooth model, followed by parameter design and spatial kinematic analysis. A discrete element model of interactions among the bionic straw-cleaning disc, straw and soil was developed. Operating speed, forward inclination angle and lateral inclination angle were selected as experimental factors, with straw-cleaning rate and maximum transverse straw-throwing distance as evaluation indices. Single-factor tests and a three-factor five-level quadratic regression orthogonal rotational combination test were conducted. The optimal operating speed, forward inclination angle and lateral inclination angle were 7.13 km/h, 27.73° and 14.05°, respectively. The predicted straw-cleaning rate and maximum transverse straw-throwing distance were 90.16% and 30.00 cm, respectively. Comparative simulations showed that the bionic disc produced more continuous high-velocity regions of straw particles and more pronounced transverse movement than the conventional notched straw-cleaning disc. Bench tests using the rounded optimal parameters produced a straw-cleaning rate of 89.38% and a maximum transverse straw-throwing distance of 27.52 cm. The device met straw-cleaning requirements when straw coverage did not exceed 1.5 kg/m2. Field tests showed that the straw-cleaning rate remained at or above 84.74% at operating speeds of 6~8 km/h. Compared with the conventional notched straw-cleaning disc, the maximum increase in straw-cleaning rate was 5.99 percentage points, corresponding to a relative increase of 7.61%, while the maximum increase in transverse straw-throwing distance was 3.95 cm. The device improved straw-cleaning performance and transverse straw-throwing capacity under spring maize straw coverage conditions in Northeast China.