Characteristics Analysis of Working Mechanisms for Servo Mechanical Presses

Abstract

Based on analysis of press working characteristics, some of the main kinematics requirements for working mechanisms of servo mechanical presses were put forward: fast in empty stroke, slow and uniform in working stroke and big force gain. Crank link and knuckle-straight link are the most common working mechanisms in mechanical presses. To meet the requirement of servo mechanical presses, another mechanism, knuckle-triangle link, was designed. The kinematics simulations of the three mechanisms for a 1600kN press were conducted by dynamic software ADAMS. Knuckle-triangle link had the most uniform and lowest slide’s average velocity and biggest force gain within the working stroke. For the same nominal pressure of 1600kN, the required input torque of knuckle-triangle link was 9108Nm. In comparison with crank link and knuckle-straight link, the crank’s input torque was reduced by 84% and 76% respectively without considering the influence of friction and inertia. In conclusion, knuckle-triangle link mechanism is more suitable for large-tonnage servo presses.