Non-circular belt transmission design of mechanical press

The quality of parts manufactured by metal forming operations depends on the kinematics of the mechanical press in a large degree. Non-circular belt transmission with a rotational angle-dependent speed ratio in the press drive mechanism offers a new way to obtain optimum stroke-time behaviors for specific metal forming operations in terms of manufacturing. In this work, the mathematical model for mechanical press driven by non-circular belt transmission is established with the concept of polar coordinate equation for tangent curves introduced, and a general design method of non-circular belt pulley pitch curves and slack for transmission system is proposed. Compared with traditional crank-slider press, numerical simulation results demonstrate that mechanical press with non-circular belt transmission has a lower speed under deep drawing operation and a quick-return characteristic under non-loading stage, which is suitable for blanking and deep drawing products that are made of poor plasticity and embrittlement material. Furthermore, the slack of non-circular belt transmission for mechanical press is calculated under operation, which can provide a theoretical basis for the design of take-up mechanism. (C) 2012 Elsevier Ltd. All rights reserved.