基于东方蝼蛄爪趾的仿生旋耕刀设计与试验

Design and Experiment of Bionic Rotary Blade Based onClaw Toe of Gryllotalpa orientalis Burmeister

为了降低旋耕刀耕作时的能耗,本文基于东方蝼蛄前足爪趾轮廓拟合曲线的特征,利用逆向工程技术将东方蝼蛄前足爪趾1、2、3、4的轮廓曲线依次排列于IT245国标旋耕刀的正切刃与回转半径末端边缘,设计了仿生旋耕刀。建立南方粘湿土壤旋耕刀相互作用仿真模型,分析不同刀轴转速下国标旋耕刀、仿生旋耕刀扭矩和三向阻力的变化规律,结合室内土槽试验分析刀轴扭矩的变化趋势,验证离散元仿真模型的有效性。单刀受力仿真分析表明,仿生旋耕刀与国标旋耕刀的水平阻力、垂直阻力与侧向阻力均随着刀轴转速的增加而逐渐增大。在3种刀轴转速下,除侧向阻力以外,仿生旋耕刀受到的水平阻力与垂直阻力的最大值均比国标旋耕刀小。在刀轴转速150 r/min时,仿生旋耕刀较国标旋耕刀水平阻力与垂直阻力的最大值分别降低了9.91%与9.09%;在转速200 r/min时,分别降低了5.78%与9.74%;在转速250 r/min时,分别降低了4.95%与6.38%。土槽扭矩试验表明,仿生旋耕刀与国标旋耕刀的仿真值与试验值变化趋势相同,且随着刀轴转速的增加扭矩逐渐增大,最大相对误差为13.23%。在3种刀轴转速下,仿生旋耕刀较国标旋耕刀平均扭矩分别降低了10.53%、4.46%、3.49%。本研究可为旋耕刀减阻降耗和耕作能耗分析提供借鉴。

Field rotary tillage is an important part of the agricultural production process.In order to reduce the energy consumption during rotary blade farming,based on the characteristics of the contour fitting curves of the forefoot toes of Gryllotalpa orientalis Burmeister,using reverse engineering technology,the contour curves of the first,second,third and fourth claw toes of the forefoot were arranged in sequence on the cutting edge and the end edge of the gyration radius of the IT245 national standard rotary blade to design a bionic rotary blade.A soil-rotary blade interaction model of the southern clay-wet soil-blade was established to analyze the changes in torque and three-axis working resistance of the national standard and bionic rotary blade at different rotate speeds.Combined with the indoor soil bin test,the trend of the torque on the tool shaft was analyzed to verify the validity of the discrete element simulation model.The force simulation analysis of a single blade showed that the horizontal resistance,vertical resistance and lateral resistance of the national standard and bionic rotary blade were all gradually increased with the increase of speed.At three different rotate speeds,except for the lateral resistance,the maximum horizontal and vertical resistance of the bionic rotary blade were lower than that of the national standard rotary blade.Compared with the national standard rotary blade,when the rotate speed was at 150 r/min,200 r/min and 250 r/min,the maximum horizontal resistance of the bionic rotary blade was reduced by 9.91%,5.78%and 4.95%,respectively,and the vertical resistance of which was reduced by 9.09%,9.74%and 6.38%,respectively.The soil bin torque test showed that the simulation and experimental values of the two rotary blades had the same changing trend.The torque was gradually increased as the increase of rotate speed,and the maximum relative error was up to 13.23%.Compared with the national standard rotary blade,when the rotate speed was at 150 r/min,200 r/min and 250 r/min,the average torque of the bionic rotary blade was reduced by 10.53%,4.46%and 3.49%,respectively.The research results can provide a certain reference for the analysis of drag reduction and energy consumption of the rotary blade.