曲柄摇杆行星系取苗机构参数匹配与优化

Parameters matching and optimization of seedling pick-up mechanism with crank-rocker planetary gear train

为满足水稻种植农艺的要求,将秧夹式插植臂应用在高速水稻插秧机行星系旋转机构中,设计一种新型曲柄摇杆行星系取苗机构。阐述高速水稻插秧机曲柄摇杆行星系取苗机构的结构特点和工作原理,建立取苗机构的数学模型,通过MATLAB编程对取苗机构的静轨迹进行了分析与优化,对影响秧夹轨迹运动特性的4个主要参数分别选取不同的数值进行优化,得到适合该机构并满足农艺要求的一组最优参数:取苗机构初始位置角a_5=-6.05e-2(°),行星轮半径R=78 mm,插植臂长度l_c=112.51 mm,插植臂的初始位置角a_6=22.73e-2(°)。根据优化结果建立取苗机构的三维虚拟样机模型。通过RecurDyn动力学仿真对理论分析进行验证并试制样机进行试验。研究结果表明,该取苗机构动力学特性良好。

In order to fulfill the agronomic demand of rice planting,the transplanting arms with grippers were applied to the planetary rotation mechanism of high-speed rice transplanter, and a new seedling pick-up mechanism with crank-rocker planetary gear train was designed. The structural features and working principle of seedling pick-up mechanism with crank-rocker planetary gear train was discussed, and the mathematical model of the seedling pick-up mechanism was established. The static trajectory of seedling pick-up mechanism was analyzed and optimized through MATLAB programming, four main parameters influencing the trajectory characteristics of seedling pick-up arms were optimized by choosing different numbers, and a series of optimal structural parameters fulfilling the agronomic demand of rice planting were obtained. The initial position angle of seedling pick-up mechanism（a_5） was-6.05e-2（°）, the radius of the planet wheel（R） was 78 mm, the length of seedling pick-up arms（l_c） was 112.51 mm, and the initial position angle of seedling pick-up arms（a_6） was 22.73e-2（°）. The virtual model of the proposed seedling pick-up mechanism was built with the optimization result, The theoretical analysis was verified by Recur Dyn dynamic simulation and prototype test. The results show that the kinematical properties of the seedling pick-up mechanism are better.