二十面体机构构型设计与分析  

Configuration Design and Analysis of Novel Icosahedron Mechanism

作　　者：刘婧芳[1,2] 曹亚柯 丁华锋 LIU Jingfang CAO Yake DING Huafeng(College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China Beijing Key Laboratory of Advanced Manufacturing Technology, Beijing University of Technology, Beijing 100124, China)

机构地区：[1]北京工业大学机械工程与应用电子技术学院,北京100124 [2]北京工业大学先进制造技术北京市重点实验室,北京100124

出　　处：《农业机械学报》2017年第10期370-379,共10页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51475015)

摘　　要：基于具有对称性和对偶性的正十二面体,设计了一种以三、四、五边形为耦合节点的二十面体单移动可展机构。首先,在正十二面体的十个面上添加一种顶点,通过增加顶点种类以增加耦合节点种类,从而得到具有三、四、五边形结构的节点构件。根据构件连接情况设计四类替换构件,将替换构件用转动副(R副)依次连接,构造耦合机构基础模型。其次,基于螺旋理论应用分流法计算其自由度。最后,进行主动输入选取分析及构建耦合机构的三维模型,设置方向相反的驱动条件分别进行仿真运动,应用Matlab得到动平台和节点构件的位置变化曲线,仿真结果与理论分析结果相统一,表明提出的机构具有伸缩运动特性。It has remained a great challenge to develop coupled mechanisms in kinematics. Polyhedrons with various appearance and symmetric configuration attract more and more attentions and provide possible basic modes for the design of coupled mechanisms. Based on the symmetry and duality of the regular dodecahedron, a movable icosahedron mechanism with single mobility was designed, where the coupling nodes were composed of triangles, quadrilaterals and pentagons. Firstly, in order to design the coupling nodes with triangles, quadrilaterals and pentagons, each vertex was added to the ten faces of the icosahedron and the node variety was increased by adding types of vertexes. The common edge of the original regular pentagon was replaced by four edges. Four edges made up a quadrilateral. The common edge of the original regular pentagon became a diagonal of the quadrilateral. Then four kinds of replacement components were designed according to the connection of each component, and the replacement components sequentially were connected by rotational joints to construct a basic model of the coupled mechanism. Secondly, mobility of the mechanism model was calculated by the shunting method based on screw theory. The coupled mechanism was divided into five identical branches according to the shunting tags. As long as the constraints of one branch were determined based on screw theory, the constraints of all branches to the moving platform was obtained. Then mobility of the coupled mechanism was obtained, which showed the coupled mechanism had a translational freedom. Finally, active input selection was analyzed and the three-dimensional model of the coupled mechanism was established. Two opposite driving conditions were set up in the simulation, and position curves of the moving platform and the node components were got by Matlab. The simulation results were consistent with theoretical results. It further showed that the proposed mechanism had the characteristics of stretching motion.

关 键 词：多环耦合机构 二十面体 自由度 运动分析 

分 类 号：TH112[机械工程—机械设计及理论]