Fundamental Study on Novel On-Machine Measurement Method of a Cutting Tool Edge Profile with a Fluorescent Confocal Microscopy

We propose a novel, on-machine method of measuring the profile of the cutting edge of a tool by using the cutting fluid on the tool surface. Despite an environment of on-machine tool profile measurement, it is difficult to measure a cutting edge profile by using conventional optical methods due to interference from the cutting fluid on the tool surface. To overcome this problem, we propose a profile measurement method that uses confocal fluorescent detection from the cutting fluid on the tool surface. Moreover, for precise measurements, a method that corrects for the thickness of the cutting fluid is provided. Fluorescence from the surface of a silicon wafer coated with a fluorescent dye that is set horizontally as well as vertically to the optical axis of a developed fluorescent confocal microscope is detected. As a basic verification, the cutting edge profile of a milling tool with wear is measured using the proposed measuring and correction methods that employ a fluorescent dye. The results confirm that the proposed method can provide detailed measurements of a tool wear profile.