Kinematics Analysis And Optimization Of Single - Degree - Of - Freedom 8 - Bar Linkage Mechanism

With the rapid development of stamping industry, the requirement of stamping process is higher and higher, Upgrading of stamping machine is becoming more and more quickly. The main transmission mechanism of traditional mechanical presses mainly adopted Crank connecting rod mechanism. Because of its limited mechanical properties, it will make high noise and vibration, and the life of molds is low.Therefore, we need to find new type of transmission mechanism replace crank connecting rod mechanism. This paper proposed a new institution; we will analyze the eight-bar linkage institution. And research the optimization design of the eight-bar linkage institution. The key works are as follows:1) According to the eight linkage kinematic chain type synthesis, we will get all the eight linkage kinematic chain. According to the topological characteristics, we analysis them which need compare and calculate. Finally choose the appropriate configuration.2) We established a rectangular coordinate system about it, and then studded kinematic analysis. Based on analytic method we analyzed the angular displacement, angular velocity and angle acceleration of the bar. Then we will get the slider displacement, velocity and acceleration. We use motion simulation software to get the slider movement curve, and contrast the crank slide block motion curve. In the end we will find the eight-bar linkage institution’s advantage. On the basis of kinematics we studded the dynamics of it, and got the bar center displacement, velocity and acceleration of bar. According to the dynamic static analysis method, we calculated the inertial force and inertial moment of bar, then listed Lagrange dynamic model. The following research provided the theoretical foundation for us.3) We used ADAMS software to build the eight-bar linkage institution models which Similar to the actual mechanism. Through the method of parametric model, we optimized the length of the eight-bar linkage institution to reduce the bar center acceleration. In the end we get smaller inertial force and inertial moment.4) According to the optimization of the data, we used three dimensional design software designed parts of the eight-bar linkage institution. Then we have imported the assembly model into ADAMS. We made operation of kinematics and dynamics simulation experiments. According to the experimental results, we can get the movement of the slide block diagram. From experiment, we found that the acceleration of the center mass is reduced, eventually achieve the optimization goal.