Optimization of a double knuckle linkage drive with contrast mechanical advantage for mechanical presses

Abstract

This paper is Part II of a three part series on the design, analysis and construction of a flexible press with a double knuckle linkage drive. In Part I, this drive was shown to have the desirable characteristics of large force (mechanical advantage) over the ram stroke and controllability (constant ram velocity in the working stroke). In this paper, this linkage design is further optimized by kinematic simulation using programs CATIA and KINLYN, and an enumeration search procedure. This optimization results in increased echanical advantage in the working part of the stroke and reduced cycle times. Mechanical advanatage and ram velocity curves for the optimal design are compared with several design variants. This design with constant force and velocity in the working storke is espcially suited to applications in precision forming especially cold extrusion and sheet metal-forming processes.