System Dynamical Analysis On Flexible Roll-Die Forming Machine With Forming Force

The stress-adaptive component is a new demand in the manufacturing field today.Its processing and manufacturing method is a difficult problem in the field of engineering technology.The flexible roll-die forming technology provides a solution.In order to investigate the dynamic characteristics of the system and provide the theoretical results for the system design,the system dynamics analysis is carried out for the forming process of the first stand in the flexible roll-die forming production line.On the basis of fully understanding of the flexible roll-die forming mechanism and reasonable simplification,the first stand is selected as the dynamical analysis research subject of the electromechanical system.A new method for dynamical analysis of electromechanical systems by energy principle is proposed.The mathematical model is established by mathematical deduction.The energy equation by energy conversion relationship is established.In the equation,the mathematical expression of the energy in each part of the system is presented,including the added potential energy and kinetic energy in the system,energy consumption and plastic deformation works of the sheet material during roll-die forming.In the process of equation deduction and simplification,the coordinate transformation matrix is derived by using the Clark and Park transformation.The variables in matrix form are transformed from the natural coordinate system to the d-q coordinate system,such as voltage,current and electric resistance.In this way,the matrix form of variables is eliminated and linear operation is realized.Based on the mechanical theory of plastic forming,the velocity field and strain velocity field of the material flow are derived by analyzing the change of cross-section geometry in the metal sheet forming process.So,the work of metal sheet plastic forming is obtained.The energy loop equation of the servo motor is established by applying the energy loop principle.And the electromechanical dynamics equations are established by the combining of energy conservation equations.Then the dynamical analysis of the electromechanical system is completed.The reaction torque of the first roll is extracted from the finite element simulation of the forming process as the value of the forming torque in the equation.Due to the complexity of the equations,the Runge-Kutta numerical solution method is applied to solve the equations in MATLAB.The driving current,spindle speed and acceleration of each motor are obtained.The speed and displacement of the moving frame in x direction are fit for the law of motion.The value of current is within the allowable range of the actual motor current,and it is in accordance with the law that the frequency of three-phase current is determined by the spindle speed of motor.The calculation results are ideal and provide a basis for further theoretical research.