Development of an automatic polishing system for metal molds and dies. (2nd report. Development of a polishing apparatus with contact pressure control).

Abstract

This paper describes the development of a polishing apparatus with the contact pressure control to obtain a smooth surface for metal molds and dies. The apparatus is mounted on the wrist of an industrial robot and composed of an air spindle motor attached with an abrasive wheel, a coiled spring for pressing the spindle motor and a pulse motor to control the relative length of the spring. The features of the polishing robot system are mainly (1) the tool path generation based on the shape data of molds and dies in the CAD/CAM system and (2) the contact pressure control along the tool path on the surface. The tool path is designed so that the apparatus is perpendicular to the surface and the contact pressure is controlled by the relative length of the spring. The experimental results demonstrate that the polishing with the contact pressure control is essential and easily improves the surface roughness less than 0.4μm.