INSPECTION INSTRUMENT FOR INTERNAL SURFACE OF PIPE

摘要

PURPOSE: To enable not only adaptation to changes in the inner diameter of material to be inspected by an eddy current flaw detection means but also better detection capacity of a defect by an optical flaw detection means while allowing highly efficient flaw detection. CONSTITUTION: A lighting unit 4 and a small TV camera 5 are arranged as opposed to each other at the tip part of an inspection head 1. An eddy current flaw detection means having a rotary probe 6 is arranged behind an optical flaw detection means comprising the lighting unit 4 and the small TV camera 5. Centripetal levers 13 are set at least three points on the same circumference on the outer circumference part of the inspection head 1 in such a manner that one thereof is pivoted on the inspection head 1 while the other thereof is energized to the side opposite to the inspection head to contact the internal circumferential surface of the material 2 to be inspected. The rotary probe 6 is always maintained in the direction of reducing the diameter thereof by a coil spring 10 and at the detection of a flaw, it turns to move in the direction of expanding the diameter thereof against an energizing force of the coil spring 10 by a centrifugal force and contacts the inner circumferential surface of the material 2 to be inspected.