SELF-RUNNING DUCT-INSIDE INSPECTING DEVICE AND INSPECTING METHOD FOR DUCT INSIDE

摘要

PROBLEM TO BE SOLVED: To make it unnecessary to pull a self-running duct-inside inspecting device back, after the finish of duct inspection, without restricting its inspection range. ;SOLUTION: A self-running duct-inside inspecting device 6 has a video camera having a picture recording function, and an illuminating lamp for illuminating a photographing direction of this video camera, on a self-running truck. The truck runs with tires fitted to both ends of an axle, and the space in the direction of the axle between these tires is made narrower than the breadth of an inner tube 8 to be laid inside a duct, to make it possible for the truck to run on an inner tube 8 even if it is laid already. A stringlike substance 4 is attached to a duct-inside inspecting device 6 and a truck is caused to run delivering the stringlike substance 4 from a reel 5 from one end to the other end of the duct 1. Besides, the stringlike substance 4 left behind in the duct 1 is used as a pull wire, on the occasion of laying an inner tube 8 in the duct 1 for the next process, after inspection finish.;COPYRIGHT: (C)1999,JPO