PURPOSE: To display a sufficiently large thrust even in traveling over a long distance while the inspection operation in the pipe line is carried out.
CONSTITUTION: An automatic traveling device 30 in a pipe line is constituted connect a front locking part 1 to a rear locking part 2 through a propelling device consisting of a hydraulic pressure cylinder device 33. The front locking part 1 and rear locking part 2 are alternately locked on the pipe wall and a hydraulic pressure cylinder device 33 is alternately expanded and contracted to act like a looper and travel in the pipe line P. A plurality of cylinder chambers of the hydraulic pressure device 30 are provided and pistons fixed to a piston rod common to the respective cylinder chambers are respectively provided, so that a large pressure receiving area as a whole can be obtained to give a large thrust. Also, when existing cables have been laid in the pipe line P, a large thrust is obtained even if the sectional area of the cylinder is lessened relative to an empty space in the pipe line P.
KATAHIRA EIJU
YOKOYAMA TOMOHIRO
YOKOSUKA KOICHI
TOKYO ELECTRIC POWER CO