PIPE ROBOT

An in-pipe robot is provided with a rotary actuator 30 that rotates the drilling blade 21 in the circumferential direction of an existing pipe. A wheel body 50 provided with a traveling wheel 52 on both sides and a wheel body 70 provided with a traveling wheel 72 on both sides are supported between side frames 43 of a chassis via pins 54 and 74. The other ends of both the wheel bodies are rotatably coupled around an axle 63 of an intermediate wheel 65 as a pivot. When both the wheel bodies rotate, the intermediate wheels and the rotary actuator move above a horizontal line passing through the pin center. Each pin is disposed at the midpoint of a line connecting the center of the traveling wheel and the center of the intermediate wheel so that the rotation axis v1 of the rotary actuator coincides with the pipe center axis of the existing pipe.