| 摘要 |
PURPOSE:To stably run an arm by adjusting expansion and contraction of a feed-out device so that the gap between the arm and an L-type link has a required value. CONSTITUTION:A pressing cylinder 14 presses an arm 9 to a pressure vessel 1 through an L-type link 25 and a fulcrum pin 10 by the expanding operation to keep the arm 9 in parallel with the outside peripheral surface of the vessel 1. At this time, a gap sensor 24 detects a gap S between the rear face of the arm 9 and an end 25b of the link 25. When a turning truck 8 turns on the outside peripheral surface of a pipe 2 and the vessel 1 is gradually moved backward while forming a pipe 2 and the vessel 1 is gradually moved backward while forming a curved surface, the cylinder 14 is automatically expanded to turn the link 25 and presses the arm 9 so that the arm 9 will be parallel with the outside peripheral surface of the vessel 1. At the time, the gap S is changed to expand, and the sensor 24 detects this change, and a feed-out device 5 is expanded to prevent the arm 9 from being drawn to the inside. When the change to narrow the gap S is detected, the device 5 is contracted. Thus, a detector 18 turns while describing an approximately perfect circle with the axis of the pipe 2 as the center to detect flaws. |
