Process optimization in two spherical surface grinding processes using trajectories analysis

Abstract

A smooth spherical surface has been obtained by grinding using a precise spherical grinder and a cup-type resin-bonded diamond wheel without any polishing. Two methods were used in machining: cup-wheel spherical grinding with swing (CSGS) and cup-wheel spherical grinding with no swing (CSGNS). In this paper we propose, for the first time, a trajectories analysis approach (TAA) based on the above two methods to optimize the machining parameters in the spherical grinding process. The cup-wheel rotation speed and swing speed, spindle rotation speed, number of grinding blocks and size of the cup wheel were considered as the process variables. The surface roughness and production rate were evaluated for the optimal grinding conditions, subject to the constraints of the density of trajectories, compatible parameters, and the size of the workpiece. A mathematical model was developed and an optimization strategy was proposed for the process parameters, and verified by two experiments. The experimental results show that the TAA is valid for selecting the optimal process parameters for the two methods of spherical grinding.