In-Pipe Mobile Micromachine Using Fluid Power. Fabrication of a Small In-Pipe Mobile Mechanism Traversable Branched Pipes.

Abstract

In-pipe mobile micromachines have many applications including micro-maintenance robots for nuclear reactors and are expected to be realized in the near future. To realize practical in-pipe mobile micromachines, microactuators with sufficiently high output power are necessary and we have proposed the bellows microactuator which utilizes fluid power. In this study, an inchworm in-pipe mobile micromachine which can traverse branched pipes is fabricated using the bellows microactuators and its performance is examined. First, the performance of displacement magnification mechanisms useful in micromachines is theoretically investigated and the effectiveness of a pulley mechanism is proved. Secondly, the structure of the in-pipe mobile micromechanism is investigated. A bending and propelling mechanism using pulley mechanisms with 1 bending DOF is proposed and the structures of the front and rear supporting mechanisms are devised. Also the traveling sequence in branched pipes is theoretically investigated. Finally, an in-pipe mobile mechanism 25mm in diameter is fabricated and traveling experiments in straight and Y-shaped pipes are conducted. It is clarified that the traveling velocity in a straight pipe is increased from the output velocity of an actuator and the fabricated mechanism is able to traverse a Y-shaped pipe.