Optimal design of the toggle mechanism in servo presses

Abstract To augment the stretching capabilities of servo presses, an optimal transmission mechanism design is imperative. Firstly, a kinematic model of the servo press transmission system was established by employing the closed-vector formulation. A normalized composite fitness function, integrating the mechanism’s mechanical advantage, transmission angle, and slider velocity fluctuation as optimization criteria, was constructed to quantify the overall performance. Subsequently, a genetic algorithm was implemented to execute the optimization design under geometric, kinematic, transmission angle, and stroke-speed ratio constraints. The findings indicate that the optimized transmission mechanism reduces the maximum speed during the working stroke by 54.40%, increases the slider displacement during the working stage by 2.27%, and increases the proportion of the working stroke by 96.01%, effectively improving the overall forging performance of the press.