小口径ガラスロッド端面の球面加工基礎理論と加工装置構想

Abstract

This paper proposes a new convex spherical finishing method for end of small diameter glass rods, and also describes the kinematical basic theory and the newly designed polishing machine for obtaining spherical surface on them. The distinctive feature of this method is to use the lip type finishing tool whose form is hollow and a cone shape. The inner cone surface is used for tool surface. The spherical surface on end of glass rods is able to be formed by pushing the end of them perpendicu-larly against the inner cone surface of the tool, rotating the glass rods at low speed and the tool at high speed. The experiments are performed for optical small diameter glass rod works (φ2.0×L110 mm), using lip type grinding tool filled up with 7 μm diamonds uniformly to the inner cone surface and lip type polishing tool coated with soft pitch under supplying CeO2 powders slurry. Following conclusions are obtained : (1) Spherical radius R of the work can be changed continuously with adjustment of the work position against the tool. (2) Surface roughness and form accuracy values of spherical surface reach approximately 2 nm Rmax and 0.1 μm P-V, and R is 2.5 mm in agreement with the calculated value on the experiments.