虚拟环境下农机箱体零件的轻量化建模与仿真

Lightweight modeling and simulation of agricultural cabinet parts in virtual environment

针对拖拉机在设计初期由于工作环境复杂,为了增加整机刚度和强度,造成整机重量过大,轻便性不足等问题,对拖拉机变速箱箱体以及后桥箱体进行轻量化设计。轻量化技术就是在保证零件拥有足够刚度和强度的前提下,通过优化分析后进行再设计,达到减轻重量的目的。以拖拉机变速箱箱体与后桥箱体为例,阐述了箱体的设计要求与功能、设计步骤以及箱体刚度和强度的校核方法,完成箱体选型后,结合箱体内部齿轮组、轴等传动零件结构尺寸确定主要尺寸参数,使用Solidworks 2016进行虚拟环境下的建模设计;使用NX 10.0中的有限元分析模块对箱体零件进行静态有限元分析,箱体零件在慢1档时输出扭矩最大,在此工况下进行静态受力分析得到初步优化结果;最后,通过HyperMesh进行箱体零件网格划分,采用变密度法进行拓扑优化,得到优化结果。结果表明:在满足箱体的刚度、强度等要求的同时,对轴承受力位置进行加厚与调整,箱体外部受应力较小位置通过挖孔等减重,最后使变速箱箱体减重5.6%,后桥箱体减重14.3%。

The working environment of the tractor is complex,so it is necessary to increase the rigidity and strength of the complete machine,which leads to large weight and insufficient portability of the complete machine in the early stage of the design.Therefore,the lightweight design of the tractor gearbox case and rear axle box body are carried out.Lightweight technology is to design parts after optimization and analysis on the premise that the parts have sufficient rigidity and strength,so as to achieve the purpose of reducing parts weight.The tractor gearbox case and rear axle box body are taken as examples to explain the design requirements and functions,design steps and checking methods for box rigidity and strength.After the box body selection is completed,the main dimension parameters are determined according to the structural dimensions of transmission parts such as gear sets and shafts inside the box body,and Solidworks 2016 is used to conduct modeling design in virtual environment.The finite element analysis module in NX 10.0 is used to carry out static finite element analysis on the box parts,and the output torque of the box parts is the largest when the box parts are in the first gear.Under this working condition,the static force analysis is carried out to obtain the preliminary optimization results.The box parts are meshed by HyperMesh,and the variable density method is used for topology optimization to obtain the optimization results.The results show that,while meeting the requirements of rigidity and strength of the box body,the bearing position of the bearing is thickened and adjusted,and the lower stress position outside the box body is reduced by digging holes,so as to reduce the gearbox case by 5.6%and the rear axle box body by 14.3%.