Examining the profile accuracy of grinding wheels used for microdrill fluting by an image-based contour matching method

摘要

The helical flutes in drills are usually made by grinding cylindrical rods to form helically swept grooves. In order to maintain the quality of the fluting process for microdrills, grinding wheels must be trued and dressed regularly. It is therefore quite important to examine the profile accuracy of trued and dressed wheels. With the aid of machine vision, this paper presents an image-based method for examining the profile accuracy of grinding wheels used for microdrill fluting. Using thin plate specimens ground to yield two-dimensional contours for duplicating the topographical profiles of inspected grinding wheels, digital images of the ground contours can be captured in order to detect their coordinate data by edge detection. A contour matching method is then developed to calculate the relative deviations between the theoretical and detected inspected contours, and the profile accuracy of the inspected grinding wheel can thus be indirectly evaluated. To test the proposed method, a machine vision system was built, and experiments examining diamond grinding wheels used for machining helical flutes in microdrills were conducted. The results showed that the proposed contour matching method could achieve sufficient repeatability in the examination of wheel contours.