| Over the past decade,the servo presses have shown a rapid development momentum.The new processing equipment possesses a number of unique advantages in many aspects including the viariable speed control of the slider,the transmission mode,low noise and low operation costs,and is being widely used in automotive,aerospace and other industries of high strength,plastic molding of light and difficult forming materials.In order to give full utilize of the servo motor control to improve the pressure processing production of high quality,high efficiency,high energy efficiency,many companies need to further optimize the design and the drive control mode.In this paper,the mathematic model is built through the analysis of serval typical process strokes under different transmission mechanism.To study the solution base on the methematic model,a reasonable control strategy is put forward.At the same time,a experimental emulation platform based on dual servomotors is constructed to emulate the characteristics of several typical slider strokes through different transmission mechanism,in order to study the working characteristics,so as to apply reliable strategy for the design and construct of the servo motor,and also control strategy.Further more,the composite forming combined the electromagnetic pulse assisted incremental drawing forming with the servo press stamping is studied,in order to provide a technical route for the realization of intelligent electromagnetic pulse forming.This work is of great importance for the theoretical research and practical application in the servo press transmission system development and its control strategy optimization.(1)The dynamics and kinematic characteristics of the single-degree-of-freedom servo press which are widely used in industrial production are analyzed and studied,and the common slide load displacement curve is constructed,and the optimization strategy of load torque output curve is worked out.On the basis of this,the 2-degree-of-freedom synchronous and asynchronous driving are studied by using the 2-degree-of-freedom driving mechanism.The curve of the variable motion curve of the slider is constructed with the sine cluster curve.The planning C2 curve satisfies the gradual change condition of the slider acceleration,and the acceleration of 0 at the processing point,which is suitable for the process of high servo control including the deep drawing,etc.Based on the vector method,the correspondence between the crank angle and the displacement of the slider stroke is obtained by analytic method.The approximate displacement of the crankshaft angular displacement is obtained by fitting the stroke using the Fourier series,and the approximate solution of the angular velocity and acceleration are derived.The crank connecting rod and the triangular shaft mechanism are used as the analysis objects of the transmission mechanism of the servo press.According to the mechanism and the mechanical dynamics principle,the planar linkage mechanism kinetic and dynamic characterists of different mechanical parameters under different mechanical parameters have been solved,and whether the output torque curves of the servo motor meet the requirements are checked and modified.(2)From the perspective of two-degree-of-freedom synchronous asynchronous control,the control strategy of servo press under double degree of freedom is studied.Taking the two-degree-of-freedom nine-bar mechanism as an example,the control strategies of the two crank motors as the power input link mechanism are studied respectively.Regard the two-degree-of-freedom nine bar mechanism as a planar five bar mechanism combined with triangle toggle mechanism,consider the planar five bar mechanism as the drive source,and the triangle toggle mechanism as the execute structure of displacement as well as the force.The influence of the size change of the bar structure on the stroke curve of the slider is systematically studied.(3)To study the application of load simulation system in servo press control experiment,servo press load emulation system for simulating output torque under different transmission mechanism with dual servo motor is constructed,and the emulation of various mechanical loads in laboratory environment have been realized.The emulation system can be used to study the control strategy of the linear and nonlinear load system,the theoretical and methodological problems of experimental simulation have been solved.Therefore,the servo press design and its control strategy can be optimized with the application of the load emulation system.It is of great theoretical and practical significance to the development of servo press drive system and its control strategy.(4)The application of servo press control in electromagnetic pulse assisted incremental drawing forming has been investigated,the method of progressive drawing of cylindrical parts by using the servo press gradually under the action of electromagnetic pulse drawing and flange electromagnetic pulse has been explored,an new automatic control scheme of progressive drawing step is proposed,therefore the works have provided technical basis for the intelligent application and the digital control for the further research of electromagnetic pulse assisted incremental drawing forming... |
PDF Full Text Request