Research On Vibration Ansysis And Vibration Reduction Of High Speed Punching Press:Multi Domain Unified Simuation

Continuously extending of the industrial capacity of air condition,refrigerator and automobile promotes the annually increasing of market demand of the heat exchanger fin,and puts forward higher requriment on the annual production of the fin part high-speed punch press and its stamping speed.While vibration problems occroured on the punching press,which induced by the increasing stroke frequency,are great threats to stamping quality of the stamping parts,and to precision and service life of the stamping die and the punching press.The research of this thesis was financially corporately supported by the Produce-learnresearch Major Project of Education Ministry in Guangdong(project title: Key Technologies Research and Product Development on Precision Speed Servo Automatic CNC Punch Presses;project No.2012B091000128),and the Project of Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology(project No.PEMT1202),and the EU FP7 Marie Curie International Research Staff Exchange Scheme(IRSES)MatProFuture Project(Project identification No.FP7-PEOPLE-2012-IRSES),a certain heat change fin part high speed punching press was secleted as the object of study,a integrated method of combining theoretical analysis and experimental study was employed to explore vibration problems of the high speed punching press;and vibration reduction study of the punching press were carried out by means of dimension parameter designing of the foundation,structural modifications of the frame,parameters adjustment of the hydraulic system,as well as running parameter designing of the servo motor and the slider.For the multiformity of factors involved in the vibration problems as well as the complexities of the vibration mechanism of the high speed punching press,kinematic and dynamic equations of the crankshaft-slider mechanism,electromechanical coupling mathematical equations of the servo motor and the cranksaft,three degrees of freedom vibration mathematical equations of the punching press were first established.On basis of these equations,the reason for phenomenon high speed punching press are more prone to vibrate than average speed punching press was explained,interactional relationship between parameters of the servo motor and mechanical structure of the punching press.Against the series of problems that geometry size and structure of the research project can not be reflected in the mechanical multi-body models established in the multidisciplinary simulation platform,a technical approach that importing the three-dimensional entity model of the punching press into the the simulation platform was proposed,and in which transitive relationship between kinematic and dynamic information of each mechanism were established,so as to realize the accurate modeling of the mechanical subsystem of the multi-domain model of the high speed punching press;a method to add kinematic and dynamic ports in the multidomain was porposed,to establish complex connection models of each mechanism of the high speed punching press;a proach that loading importing on basis of the mathematical function and curves was presented to importing multi-position stamping forces of the heat change fins,which depens on displacement of the slider,into the multi-domain unified model accurately.According to differences of the discipline theories involved in the modelling and analysys,the high speed punching press was divided into series sub-domains such as mechanical multibody,motor and controller,stamping of the fin part,hydraumatic subsystem and the foundation.Models of these subdomains were established and organized into a multi-domain unified model.Depending on the measurement coordinate and the evaluation criteria of vibration proposed in this reseach,service behavior and vibration quantity of the punching press under various operation conditons were predicted,to acquire optimization space of vibration of the punching press.Amplitudes of the frame and slider by multi-domain unified simulation on the punching press were compared with the analytical solution results of the Vibration mathematical model,to verify theoretical accuracy of the multi-domain unified model established.Multi-domain unified simulation analyze of the punching press with installation of the foundation and the hydraulic subsystem were carried out,the results prove that vibration quality can be decreased by the the installation of the foundation and the hydraulic subsystem.Vibration reduction reseach of the high speed punching press was accomplished from the perspective of parameter designing of each multi-domain: topology optimization designing of the slider structure was carried out to obtain the lightweight structure of the slider on premise of guarantee its stiffness and strength,to decrease inertia force of the slider and then realize reduction of the vibration.Vibration natural frequency as well as vibration mode of primary components of the punching press were analysed by adapting finite element modal analysis method,the results showed that the frame is component which more tend to resonate with the motivation of the punching press,and the vibtaion modal of the frame is the first order torsional vibration at the top of the frame;according to the modal analysis,modifications of the frame structure were implemented to increase its natural frequency,vibtation reduction was achieved by pull the natural frequency away from the motor frequency of the punching press.a series foundations of the punching press were designed to explore the influences of dimension of the foundation on the vibration quality,and suitable dimension that reducing the installation area and reducing the vibration of the punching press was obtained.Variable speed curve of the servo motor was designed according to stamping features of the heat exchange fin part,and PID mothed was adapted to control the speed of the servo motor,the results showed that acceleration of the slider significantly decreased during the stamping period under the designed variable speed curve.Influence rule of the peasure of hydraulic system on the vibration quality of the punching press was explored,and hydraulic peasure that benefits vibration reduction was achieved.On the other hand,influences of flooding velocity and pressure drop of the relief valve on efficiency of overload protection to the punching press was completed,considering the possible situation that when the stamping die and frame suffer overloads.The research conclusions achieved in this reseach lay a solid foundation for vibration reduction of high speed punching press in practical engineeringExperimental measurements were made to achieve vibration accerleration of the slider,lower cross beam,side column and movable cross beam,as well as rotational speed curves of the crankshaft for different speeds of the servomotor;curve processing such as integration and filtering of the measured curves were carried out to achieve vibration qualities of the working components of the punching press.Aiming at the measured phenomenon that the measured results by the acceleration sensors installed on the front side view of the punching press are higher than the results by sensors installed on the reverse side,reasons for the phenomenon were analysed,and conclusions about influence of transmission mechanisms and their installation location on vibration of the frame were proposed.Besides,experimentally measured and simulated curves of the acceleration as well as rotated speed curves of the componetns of the punching press were compared,the results reflected that whice were were basically consistent,and accuracy and reliability of the multi-domain unified model of the punching press as well as the simulated results in this reseach were proved.