Technique for cylindrical part inner surface inspection

摘要

A system and method for inspecting inner surfaces (22) of cylindrical parts (20) includes a line scan camera (30), a pair of light emitting diodes each directing light toward the inner surface (22), and a mirror (36) disposed in the cylindrical part (20) at a 45 degree angle relative to the inner surface (22). The camera (30) and mirror (36) remain in a fixed position while the cylindrical part (20) rotates continuously about a center axis (A) and the images are acquired. The cylindrical part (20) is then moved laterally along the center axis (A) and the images are again acquired as the cylindrical part (20) rotates about the center axis (A). An unwrapped display of the inner surface (22) is generated and used to automatically identify defects (24) on the inner surface (22).

主权项

1. A system for inspecting inner surfaces of cylindrical parts, comprising:
a plurality of cylindrical parts having different inner diameters, each of said cylindrical parts including an inner surface presenting said inner diameter and extending circumferentially around a center axis and longitudinally between opposite ends to present a bore, a camera with a lens for acquiring images of said inner surface while said cylindrical part rotates 360 degrees about said center axis; said lens of said camera being disposed outwardly of said cylindrical part; said lens remaining in a fixed position while acquiring said images of said inner surface and while said cylindrical part rotates 360 degrees about said center axis and moves longitudinally along said center axis; a light source disposed outwardly of said cylindrical part for directing light to said inner surface of said cylindrical part; a mirror disposed in said bore of said cylindrical part at a predetermined and fixed position along said center axis while said cylindrical part rotates 360 degrees about said center axis and moves longitudinally along said center axis and while said camera acquires said images of said inner surface; said mirror including a mirror surface being disposed at an angle relative to said inner surface for reflecting the light from said light source to said inner surface and from said inner surface to said lens of said camera; said mirror surface being disposed in a fixed position on said center axis relative to said inner surface of said cylindrical part while said cylindrical part rotates 360 degrees about said center axis and moves longitudinally along said center axis; said lens and said mirror surface remaining in a fixed position until said camera acquires images of the entire inner surface between said opposite ends of said cylindrical part, and wherein said mirror is spaced from said camera by a first distance and spaced from said inner surface by a second distance, and a sum of said first distance and said second distance is fixed while said camera acquires images of said inner surfaces of each of said cylindrical parts.