Study On Dynamical Characteresitics And Some Design Problems Of Large-Scale Forging Manipulator

The forging manipulator is the main matching equipment in the forging press industry, and it is also important mechanical equipment in our country. It can also improve the manufacturing capacity of large forging, accuracy of manufacture, productivity efficiency and material utilization consumedly and reduces energy consumption if it coordinates with processing equipment. Mastering the central design and manufacture technology of the large scale forging manipulator is an urgent mission of heavy industries in China at present.The principal characters of the large scale forging manipulator is heavy loading capacity, big inertia, multiple degrees of freedom, and manipulation with multidimensional force-displacement. It is difficult to design a large scale forging manipulator because of its mechanism complication, kinematics and dynamics characteristics. This dissertation combines with the National Natural Science Foundation research projects and enterprises subject studies the mechanism theory, the choice of mechanism form, the kinematics and dynamics characteristics of the main working system and so on, and a virtual prototype model of the large forging manipulator is established aiming at designing the large scale forging manipulator which has good combination property, suits to our country national conditions and has important engineering value and theory significance.The research status of the large-scale forging manipulator are summarized. The dynamic characteristic research aim and key design problems have been proposed according to the research duty of enterprises. Based on the structure form of the traditional forging manipulator, the forging manipulator of parallel link type and the forging manipulator of swing lever type have been analyzed comparatively.The workspace and the range of movement of two kinds of forging manipulators are obtained through the kinematics analysis with the Matlab/Simulink software. According to the basic movement requirements, the structure form and the reasonability of the structure parameters are discussed. According to the contrast of these two types, the parallel-link forging manipulator would be a more reasonable structure.3D mechanical structure models of the parallel-link forging manipulator are established after preliminary design. And then the virtual assembly with checking the constraints and interference are done, receiving a reasonable 3D assembly model lastly. The virtual prototype models of forging manipulator are established with reasonable constraints and drive, after the kinematics simulation, receiving the forging manipulator work space of different conditions. Set up the load condition according to the actual demand. Dynamics simulations of the forging manipulator which moves up and down and swings up and down are carried on in details with the ADAMS software. Dynamics characteristics of two typical movements of the forging manipulator are analyzed.Components of arm support system (connecting bar, connecting piece and so on) are little rigidity and have greatly influence on dynamic characteristic of the machine. So rigid connecting pieces between rear pushing arm and vise jaw is replaced by flexible. Then the rigid-flexible compound model of the forging manipulator is established. Simulation of the forging manipulator when it moves up and down is carried on. Contrast analysis between simulation results and rigid simulation results is carried on, the rigid-flexible compound model has a better performance.It is very important to master the inherent dynamic characteristics of the key components during the forging manipulator design process. Use finite element to calculate the modal parameters of the main components and analyze modal matching of the whole structure system of forging manipulator, then get the modal matching graph of forging manipulator.Clamp mechanism is one of most principal mechanisms of forging manipulator, and the calculation of the clamp force and the design of clamp mechanism are very important to the design of the whole machine. This dissertation introduces the structure and working principle of large-scale thesis forging manipulator, discusses the calculation method of clamping force, sets up the mathematical model of clamp mechanism for optimization design, uses genetic algorithm to optimize the parameters of clamp mechanism, reduces the force of hydraulic cylinder significantly.This dissertation applies the modern design theory and method to large-scale forging manipulator design, and the research about the large forging manipulator design, the modeling of mixed rigid-flexible body and virtual prototyping simulation, the modal matching analysis of key components and optimization design of clamp mechanism, has been used in the exploiter of new large-scale forging manipulator system, and provides the basis for large forging manipulator design.