Study on Detection Method of Inner Wall of Small-Diameter Workpiece Based on Cone Reflector

The image detection of the inner wall of the small-diameter workpiece is a difficult problem all along. The industrial endoscope is a common solution of this problem, but its measuring repeatability cannot be guaranteed and it results a large image distortion. In this paper, for this problem, a new method based on the cone reflector has been presented. Firstly, this method introduces a 45-degree cone reflector innovatively, which is placed within the workpiece. Secondly, the optical devices are placed outside, which simplifies the measuring structure and make the adjustment of the optical system easier. Finally, an image conversion method is proposed, making the image observation more intuitive. Though analyses and experiments, the resolution of images obtained from the inner wall can be achieved 10 mu m/pixel. Meanwhile, the efficiency of measurement has been greatly improved.