考虑正弦机构滑块的摩擦力和曲柄柱销处的接触变形,运用键合图建模方法针对正弦机构进行动力学建模与仿真研究。根据摩擦力的分段特性,引入功率结型结构,将摩擦力分为4个状态,建立了摩擦力的非连续键合图模型。曲柄柱销与运动杆件之间的接触变形用1-通口容性元件C表示,容度参数为接触刚度,应用键合图建模理论,建立包含摩擦力和接触处弹性变形的正弦机构键合图模型,运用20-sim仿真软件对模型进行了仿真分析,仿真结果表明:摩擦力和接触处的弹性变形将引起正弦机构在换向时产生不连续和冲击。为了验证键合图模型的正确性,用动力学仿真软件ADAMS对正弦机构进行了动力学仿真,得到滑块速度与摩擦力曲线。仿真结果对比分析表明:建立的考虑摩擦与接触变形的正弦机构键合图动力学模型的正确性。
We use the bond graph theory to establish the dynamics model of a sine mechanism,taking into account the friction of its slider and the contact deformation of its crankpin.According to the section properties of friction,we divide the friction into four states and then establish its non-continuous bond graph model.Representing the contact deformation at both the crankpin and the motion rod with the 1-portal capacitor and assuming that its capacity parameter is contact rigidity,we set up the bond graph model of the sine mechanism that contains the friction and the elastic contact deformation.We use the 20-sim simulation software to simulate the bond graph model.The simulation results show that the friction and the elastic contact deformation cause non-continuity and impact when the sine mechanism reverses its direction,and then we give the reasons why these happen.We use the ADAMS software to perform the dynamics simulation of the sine mechanism,thus obtaining the speed of the slider and its friction curve.The comparison of the two types of simulation results verify the validity of the bond graph model which is established by us and considers the friction and the elastic deformation.