Key Technologies And Experimental Research On Heavy-duty Servo Mechanical Presses With Parallel Topology

Heavy-duty stamping equipment is the necessary condition for theproduction of high-productivity, high-quality and low-cost heavy forming,which reflecting the level of advanced manufacturing. This work focused onthe need of development of heavy-duty servo presses, and discussed somekey technologies on the performance modeling and analysis of heavy-dutyservo presses. These key technologies include type design of newmulti-actuation mechanical presses with parallel topology, the coordinationmethod between actuation plan and load capacity, error modeling andaccuracy analysis, dynamic modeling and evaluation of driving performance,the impact of the inertia of moving parts on the dynamic response of thesystem, and parameters design of the dual screw actuation mechanism. Theresults of this study provide a theoretical basis for the design and research ofheavy-duty servo presses. This dissertation’s main work can be concluded as:1. We proposed a family of new multi-actuation mechanical presses withparallel topology to develop high stamping capacity. The type design ofmechanical presses is performed systematically using the generalizedfunction sets (GFsets in short form) theory. Some kinds of mechanicalpresses with2,3,4,5, and6actuators are designed.2. A specific type of mechanical press with4-RRPaR&PRPaR is presented.The pose variables of moving platform are chosen as generalized coordinatesto describe the manipulator system. The closed form inverse kinematicsolutions are derived， based on which the kinematic performance and the load capacity are analyzed. According to the actual driving capability, weconstruct the evaluation of the performance of load capacity. All those lead tothe establishment of the mathematic model of the press with paralleltopology.3. The kinematic error model of the4-RRPaR&PRPaR is established. Bymeans of the sensitivity analysis, the statistically significant effects of thegeometric error sources on end-effector accuracy are discussed. Consideringthe elastic deformation of parts, static stiffness model is derived based on thestatic analysis and kinematic error model.4. Based on the fact that geometric errors of the passive chains do notenter the movement of moving platform and active chains, a separateparameters calibration method is proposed. The calibration experiment isexecuted on the press prototype of PS4S2500-MB built by cooperation ofShanghai JiaoTong University and China First Heavy Industries.5. By choosing the pose variables of moving platform as generalizedcoordinates to describe the manipulator system, the linear form of dynamicmodel is derived by the principle of virtual work and the concept of linkJacobian matrices. A typical deep-drawing process with nominal25000KNcapacity and1200mm stroke is simulated and the required driving torques arecomputed. Meanwhile, the impact of the inertia of the moving parts to thedynamic response of the servo system is discussed. These performanceanalyses provide a basis to design of the control law or the estimation ofservomotor parameters for the mechanical press.This work provides a new solution to the development of heavy-dutyservo mechanical presses, builds relatively complete theoretic base for thedesign and analysis of heavy-duty servo mechanical presses with paralleltopology.