仿蟋蟀切齿叶减阻灭茬刀片设计与试验

为了降低切茬装置切割粉碎玉米根茬所需的功耗，以蟋蟀切齿叶为仿生原型设计了2种仿生灭茬刀片。应用MATLAB软件提取切齿叶部分的轮廓特征，分析其优良的减阻特性，并将此轮廓特征应用于灭茬刀片正刀刃的设计，设计出仿生刀片A；考虑到加工难易程度和经济成本，以二次函数为轮廓特征设计出仿生刀片B。在同等工作参数（前进速度为1 m/s，刀辊转速为420 r/min，耕深为50 mm）前提下，利用ANSYS/LS-DYNA软件仿真和田间试验的方法对2种仿生刀片和原型刀片的载荷状况进行对比分析。仿真结果表明：仿生刀片A和B的最大切削力（分别为881 N和908 N）较原型刀片的最大切削力（1 079 N）分别降低18.35%和15.85%；田间试验结果表明：仿生灭茬刀片A和B的平均扭矩和变异系数分别为267.894 N·m，2.31%和275.843 N·m，2.11%，原型灭茬刀片平均扭矩和变异系数为299.712 N·m和2.33%，且3种灭茬刀片的作业质量（灭茬深度和根茬粉碎率）均可达到相关国家标准。研究结果可为灭茬刀片的减阻降耗设计提供理论指导。

Design and experiment of cricket's incisor lobe inspired stubble cutting blade with drag reduction

In order to reduce the power consumption of the corn stubble returning machine, two bionic stubble cutting blades that utilize the cricket's incisor lobe as biological prototype were designed. The contour features of cricket's incisor lobe outline were extracted by using MATLAB, and the excellent characteristic of drag reduction was analyzed. The contour features of cricket's incisor lobe outline were subsequently applied to the design of the bionic blade A. Considering the processing difficulty and economic cost, a simplified quadratic featured contour was used for the design of the bionic blade B. Under the same working parameters (speed was 1 m/s, knife roller speed was420 r/min and tillage depth was 50 mm), the load conditions of the two bionic blades as well as the original blade were analyzed and compared through the ANSYS/LS DYNA simulation and the field test. The simulation results indicated that maximum cutting force of the bionic blade A and B were 881 N and 908 N, respectively, which decreased by 18.35% and 15.85% in comparison to that of the original blade (1 079 N). The field test results showed that the average torque and the coefficient of variation of A and B were 267.894 N·m, 2.31% and 275.843 N·m, 2.11%, respectively. In contrast, the average torque and the variation coefficient of original blade was 299.712 N·m and 2.33%. Additionally, the operation quality (stubble breaking depth and stubble chopping rate) of the three stubble cutting blades met the related national standards. This research results can provide a guide for the design of new blade with drag reduction.