APPARATUS FOR INSPECTING DEFECT ON INNER SURFACE OF SOCKET OF IRON PIPE

摘要

PURPOSE:To detect the defect on the inner surface of the socket of an iron pipe having the complicated shape automatically and efficiently by moving an image sensing device and a lighting device in conformity with the shape of the inner surface of the socket of the iron pipe, partially picking up the image of the inner surface of the socket, and processing the image. CONSTITUTION:A microscope 6 is moved along the inner surface of a socket 1a. The light is emitted from an optical fiber 6b on the local part of the inner surface of the socket 1a at the specified distance and angle. The image of the local part is expanded and picked up. The emitting angle of the light from the optical fiber 6b and the image sensing angle of a camera 6a are different. Therefore, when there are a defective recess part X and a defective protruding part Y, the corresponding shadow parts X and Y are formed. The expanded image of the local part which is captured as the shadow is received in an image processing device 23. In the device 23, the luminance of each picture element of the expanded image is compared with a threshold value, and binary coding is performed. When the area of the black-color side corresponding to the shadow parts X and Y is larger than the preset value, it is judged that there is a defect on the inner surface of the socket 1a with an operating device 24.