In Situ Evaluation of Drill Wear Using Tool Image Captured on Machining Center

Abstract

Owing to the rise in demand for electric devices, there has been an increase in the need for manufacturing equipment that produces internal control board parts. To operate this machinery, several ceramic components, such as a chuck table and fastening parts, are required. Consequently, the need for efficiently and precisely machining ceramics has increased. However, ceramics are known for their high hardness, which can lead to tool breakage when using a small tool. This is often influenced by the state of the tool wear. If the drill tip breaks off and becomes embedded in the workpiece, it could take time to remove or destroy the workpiece. To prevent such problems, drills are replaced after a certain number of machining processes, or the operator visually inspects the drill’s wear condition. Unfortunately, these methods reduce machining efficiency. Therefore, we propose a device that captures drill images on a machine tool and measures the amount of drill wear to evaluate the drill’s condition. We fabricated a device to acquire drill images and attempted to quantify the drill wear condition, such as the area and width of the worn part, by analyzing the worn shape from an image of the bottom surface of the drill.