Dynamic Simulation And Experimental Study On Knuckle Servo Crank Press

Crank-link mechanisms are adopted in most traditional mechanical presses. Their force gains are small and big capacities of motors are necessary, restricting their development further. Currently, replacing the common inductive electric motors by AC servo motors becomes a new trend in forming equipments. Usually, there are no flywheels in servo presses and the working forces come directly from the instantaneous torques of the motors. So, the motor capacities in servo presses are much larger than in common presses, resulting in high costs of the equipments. It is one of the main barriers to hinder the wide application of servo presses. To develop new transmission mechanisms has become one of the most important contents in the servo press development. Meanwhile, this technique can also be used in the ordinary presses to achieve energy saving.Aiming at mechanical presses which were widely used in the manufacturing, the project introduced AC servo drive technology to forming machines, and added computer control technology, the traditional mechanical presses became a new intelligent and energy-saving toggle crank presses. In this paper, research works are as follows:(1) Through the comparison of several common transmission mechanisms, a trianglar link-knuckle mechanism was designed, and its geometric model was established by UG software.(2) Triangular link-knuckle for kinematics and dynamics was analyzed,and motor shaft load torque and the equivalent moment of inertia were calculated. Establish dynamic mathematical model of kinematics and dynamics.(3) The simulation model based on MATLAB/Simulink software was set up and the simulation experiment were carried according to the prototypal experiment parameters of a knuckle servo crank press. Establishing the working conditions in accordance with the actual stamping process, typical processes:ordinary stamping, quiet blanking, high-speed sheet metal stamping, grading suppression, precision stamping, etc. Typical process of numerical simulation were carried out, the numerical simulation can forecast the system parameters of all kinds of technology condition.(4) The kinematic simulation models for several common transmission mechanism were established, and the simulation results were compared and analyzed, which proved that the triangular link-knuckle mechanism is superior transmission. (5) Experimental study is carried out to verify whether the numerical simulation is consistent with the experimental results, and to confirm the validity of the simulation model.(6) Suggestions for improving the driving system were put forward by analyzing the press performance(Including electricity, force, motion parameters, energy consumption, etc).The research results show that the results of numerical simulation and Experimental study are very consistent, which confirmed the correctness of the mathematical simulation model. knuckle servo crank presses adopt servo motor instead of normal asynchronous induction motor as the main drive,which can solve the shortcomings of the work is not adjustable, So as to improve the performance of the mechanical presses and broaden the applicability of process, AC servo press can realize arbitrary working curves of the slider and working characteristics of flexibility, servo crank presses could save energy by 56.5% and improve mechanical efficiency 23.9% than common presses by simulation. Through the motion simulations of three common transmissions,The simulation results showed that, compared with slider-crank mechanism and equal-length knuckle mechanism, the trianglar link- knuckle has higher force gain and better quick return and approximate dwell characteristics, improving the working performances and reducing the manufacturing costs of servo mechanical presses.Based on the electromechanical system of the servo driven crank press, the numerical simulation can forecast the system parameters of all kinds of technology condition(the current, voltage, velocity and acceleration, etc.) and get random process curves under the dynamic parameter variations of servo motor, which can offer dynamic input of the servo motor for the realization of stamping process and make the crank press has the best performance to fit the specific process uses.