Overloaded Forging Manipulator Clamping Contact Force Analysis And Dynamic Characteristics

The forging manipulators are very important for the mechanization and automation in the forging process. The application of forging manipulators to achieve the flexible operation and the precise positioning, it is significant in improving productivity and reducing labor intensity. Stably and safely gripping work-piece during forging process is strongly required, and whether the gripper of a forging manipulator can achieve stable gripping depends mainly on the position and constraint pattern of contact points.After analyzing the characteristic of the grippers and the forcing principle of the tongs, the model of calculating contact forces is presented, and the contact forces are optimized by the via gradient flows with linearly constraint. The characteristics of position and contact forces in the process of gripping and operating are analyzed. By considering the dynamical characteristic of the sustaining contact, the contact force is equivalent to the force generated by spring-damper system. The dynamical contact forces and the characteristic of the work-piece are analyzed by the simulation and the experiments. The primary work and research results are as follows:(1)The calculating and optimizing model of contact forces is presented separately for the constrained tongs and under-constrained tongs, and the parameterized software for calculating contact forces is designed. Then, the contact forces and driving force are calculated for different tonnage forging manipulators. By comparing driving force in simulation with the experimental result of the prototype, it demonstrates that the modeling of contact forces is feasible.(2) The distribution of the contact points in the course of searching is discussed by using the performance indexes. The result demonstrates that the model of calculating and optimizing contact forces can give the perfect programming position.(3) The characteristic of contact forces is studied by simplifying the contact forces as the spring-damper system. The stability of the gripping and operating is analyzed in different driving forces, and the dynamical changes are studied from the simulation.(4) The real-time characteristic of operating work piece is measuring by using the laser tracker. Through analyzing the results of simulation and experiment, it is studied how the optimal gripping forces effect the stable gripping. These are significant for controlling the stable gripping of the forging manipulators.