Effect of stiffness of broach teeth and workpiece on the stresses and deflections in internal broaching

Accuracy in broaching depends on the static and dynamic characteristics of the machine tool, cutting tool and workpiece parameters and the lubricant used. Attempts have been made towards analytical determination of stress in the broach teeth that gives results that can lead to some understanding of the factors influencing the accuracy in broaching. The complexity of the broach profile and the process requires approaches to stress analysis employing finite element method (FEM), for more useful results to be obtained. There is a need to extend this approach to include the plasticity effects of workpiece to obtain more realistic estimates of deflections and stresses on the broached component. The cutting teeth and corresponding portion of the workpiece are modelled using FEM to evaluate the stresses and deflections while broaching. The influence of rake angle and thickness of the workpiece on the stresses and deflections is studied for the cutting tooth. It has been found that the stiffness of the tooth and workpiece influences the deflections and the workpiece dimensions.