Bored combustion cylinder

In this example a bored combustion cylinder has been scanned using a displacement probe that can generate data which can be used to produce a two-dimensional image of the surface or a three dimensional profile image of the surface. The data is taken only once, but can be processed in different ways as desired. An image of the inside surface of the cylinder is shown in Figure 1. The diameter of the cylinder is about 80 mm.


Figure 1. Image of a bored combustion cylinder


The cylinder has been coarse bored and then fine bored. At the top of the image there is an area of residual non cleanup of the coarse boring marks by the fine boring process. The fine boring grooves are about 120 µm deep and spaced about 400 µm apart. We can see the structure of the boring pattern by looking at a magnified cross-sectional cut through the data, which is shown in Figure 2. The probe optics inverts the displacement values.


Figure 2. Vertical cross section across the fine boring marks of Figure 1

The coarse and fine boring marks are the dominant surface features of the bored surface of Figure 1. The boring marks tend to obscure other surface features that are not as dominant, such as pores and scratches in the surface. We can see these other features more clearly by filtering out the horizontal boring lines from the image and observing the residual surface features. This is shown in Figure 3. It is clear that Figure 3 is the same surface as Figure 1 because the residual coarse boring marks are visible at the top of the image.


Figure 3. Same image as Figure 1, but with the lines from the fine boring marks filtered from the image