| 摘要 |
PURPOSE:To spot a fault position with high precision even if an object body has a curved tube part or unevenness such as weld strain by detecting the specific angle of a flaw detection arm supported pivotally on a moving body and calculating the position of flaw detection. CONSTITUTION:The rotary encoder of the moving body which moves along the outer periphery of a straight tube 1a under the guidance of a guide rail 2 detects the angle alpha of oscillation of the flaw detection arm 4 equipped with an ultrasonic probe 6 atop while supported pivotally on the moving body 13 through a pin 14. Vertex positions of the triangle formed of the weld line 13 at the boundary between the straight tube 1a and curved tube 1b and the straight line connecting the center of curvature of the arm 4 and tube 1b and the contact point of the contactor 6 with the tube 1b, etc., are calculated on the basis of the angle alpha, thereby deciding on a fault position with high precision. Further, the angle beta of inclination of the probe 6 is detected by a rotary encoder provided to a probe holding part 5 and even if the object body has unevenness such as weld strain, etc., the fault position is spotted with high precision. |
