小型叶菜收获机切割机构仿真分析与优化设计

Simulation Analysis and Optimization Design of the Cutting Mechanism for a Small Leafy Vegetable Harvester

为满足小型叶菜收获机高效节能、低成本的设计需求,使用SolidWorks进行整机三维建模,并采用RecurDyn多体动力学软件、EDEM离散元仿真软件和ANSYS Workbench有限元仿真软件进行联合仿真与数据耦合。仿真结果表明:小型叶菜收获机切割机构使用线轴承固定支持铲部件,由曲柄连杆机构驱动切割机构更好。最优切割工况为收获机前进速度V=1 m/s,电机驱动转速为R=5 r/s。在工作过程中,铲机构相对地面运动速度最快时承受阻力最大值为15.4438 N。通过对铲进行有限元静态分析得到,铲工作过程中承受的最大应力σ_(max)值为14.5 MPa,应力集中位置在铲和铲支架后部位置,最大应变量为3.3481e-10 mm,最大应变发生位置为铲两侧侧翼位置。本研究可为小型叶菜收获机铲型切割机构的结构优化提供参考。

To meet the design requirements of high efficiency,energy saving,and low cost for small leafy vegetable harvesters,this research is based on the agronomic needs of cultivation and uses SolidWorks for the whole machine's three-dimensional modeling.To ensure the cutting mechanism meets the requirements of small harvesters,this paper utilizes RecurDyn multibody dynamics software,EDEM discrete element simulation software,and ANSYS Workbench finite element simulation software for joint simulation and data coupling to conduct the simulation analysis.The simulation results show that the cutting mechanism of the small leafy vegetable harvester employs linear bearings to fixedly support the shovel components,which are driven by a crank connecting rod mechanism.This mechanism's movement trajectory can effectively cut the leafy vegetables and ensure the stubble is neat.During the cutting process,when the harvester's forward speed is V=1 m/s,the optimal driving speed of the cutting mechanism's drive motor is R=5 r/s,at which point the shovel mechanism's relative ground speed is greater than 0m/s.The main external load the shovel mechanism bears during the working process is the working resistance of the soil against the shovel,with the maximum resistance at the shovel mechanism's fastest relative ground speed being 15.4438 N.With the external load and constraints on the shovel mechanism determined,a finite element static analysis is conducted on the shovel.The analysis reveals that the maximum stress(σ_(max))the shovel endures during operation is 14.5MPa,with stress concentration occurring at the rear position of the shovel and shovel bracket.The maximum strain is 3.3481e-10mm,occurring on the flanks of the shovel.This research can provide a reference for the structural optimization of the shovel-type cutting mechanism of small leafy vegetable harvesters.