A centerless grinding unit used for precisely processing ferrules of optical fiber connector

摘要

This paper describes the development of a centerless grinding unit used for precisely processing ferrules, a key component of optical fiber connectors. In conventional processing procedure, the outer diameter of a ferrule is ground by employing a special machine tool, i.e., centerless grinder. However, in the case of processing small amount of ferrules, introducing a centerless grinder leads to high processing cost. Therefore, in order to take measures against this problem, the present authors propose a new centerless grinding technique where a compact centerless grinding unit, which is composed of an ultrasonic elliptic-vibration shoe, a workrest blade, and their respective holders, is installed on a popular surface grinder to perform the centerless grinding operations for outer diameter machining of ferrules. In this work, an unit is designed and constructed, and is installed on a surface grinder equipped with a diamond grinding wheel. Then, the performance of the unit is examined experimentally followed by grinding tests of ferrule's outer diameter. As a result, the roundness of the ferrule's outer diameter improved from the original value of around 3 μm to the final value of around 0.5 μm, confirming the validity of the new technique.