Robot-polishing of curved surface with magnetically pressed polishing tool.

Abstract

This paper describes the development of an automatic polishing machine for a free form surface with the help of a robot. The robot is installed with a magnetically pressed polishing tool which has been newly developed. This tool utilizes the magnetic field created by a small magnet within the hollow space of a ferromagnetic grinding wheel to apply holding pressure over the surface to be polished. Therefore, the need for high stiffness arm structure to exert polishing pressure is eliminated. Besides this, the robot provides easy control, because the tool possesses considerable flexibility that enables the grinding wheel to follow the curved surface independent of the robot arm whose vibration or positioning error does influence the movement path of the abrasive wheel. The cup shaped grinding wheel has three humps on the abrasive end to provide contact at three points on the free form surface, and hence, the wheel rotates smoothly around the axis and generates a polished surface required. In this paper the characteristics of the tool are investigated, and the robot control method to get a smooth surface is discussed.