Research On Kinematic Characteristics And Dynamic Performance Of Ejection Mechanism Of Cold And Warm Forging Servo Press

As one of the important transmission mechanisms on the cold and warm forging servo press,the ejection mechanism has high matching between ejection movement and slider movement,large ejection force,good rigidity,high ejection efficiency,and stable cooperation with the slider to realize the forming process of the blank.The ejection mechanism,in the modern forging automation production process,significantly,it can ensure the operational reliability of the mechanism,reduce the production cost and improve the automation production efficiency.This paper focus on researching the cold and warm servo press ejection mechanism from the following aspects:(1)The structure and principle of ejection mechanism of cold and warm forging servo press are analyzed and the parameters of cam are obtained respectively.Firstly,the operation requirements of the ejection mechanism are analyzed,the basic working principle of the ejection mechanism is introduced,and its basic composition is explained.Secondly,the structural parameters of the cam in the ejection mechanism are solved.Finally,the working period of the ejection mechanism is planned according to its motion characteristics,and the motion law of the cam follower is determined to be sinusoidal acceleration motion.(2)Kinematics analysis model of ejection mechanism of cold and warm forging servo press is established and optimized.Firstly,the common phenomenon of "material jumping" in forging production is analyzed,The relationship between displacement,velocity and acceleration of ejection mechanism is deduced theoretically,and the mathematical model of ejection mechanism is established,and the cam pressure angle of ejection mechanism is deduced.Secondly,according to the motion characteristics of ejection mechanism,taking the dimension parameters of the ejector mechanism as design variables,constraint equations consisting of mechanism interference,cam-link transmission conditions,swing rod transmission conditions and travel restriction conditions are established respectively.In order to reduce themaximum velocity and acceleration in stroke,the complex genetic algorithm was constructed by considering the characteristics of complex method and genetic algorithm,and then the optimization mathematical model of the ejection mechanism is established.The parameters of the ejection mechanism with lower maximum working velocity and acceleration are optimized by matlab software.(3)The dynamic performance of the tie rod is analyzed and the rigid-flexible coupling dynamic performance of the ejection mechanism is studied.Firstly,the natural frequency and vibration mode are obtained by analyzing the tie rod in the ejection mechanism.Secondly,Ansys and Adams software are used to simulate the ejection mechanism,and a flexible body is created in the finite element software to establish the rigid-flexible coupling dynamic model.Finally,the dynamic characteristics of ejection stage and return stages of ejection mechanism are simulated and analyzed,comparing with the simulation results of rigid-flexible coupling conditions,the relationship between the tension of each component and the deformation of tie rod is studied.(4)The fatigue life of the tie rod of the ejection mechanism is predicted.Firstly,the fatigue load spectrum of the tie rod is obtained by dynamic simulation,then the stress fatigue curve of the tie rod is obtained by theoretical calculation.Secondly,the static simulation results are obtained by finite element analysis.Finally,the analysis results,load spectrum and S-N curve are introduced into FE-Ncode respectively,and the fatigue simulation model is established to analyze the fatigue damage location and fatigue characteristics of the tie rod.