A Study on a Micro-Actuator Using Fluid Power. 2nd Report, Application for Small-Size In-Pipe Mobile Machines with a Single Power Supply Tube.

For more efficient use of micro-machines, micro-actuators using fluid power were investigated. An in-pipe mobile machine is one of practical micro-mechanisms and a simple machine using the bellows actuators was constructed previously. The machine is able to move like an inchworm due to the three actuators, however, it has to pull three power supply tubes using a large load force.To overcome this problem, this report attempted to reduce the number of tubes. After examining the performances of the bellows actuators, based on the analysis of the inchworm motion, the required characteristics were derived and a new supporting mechanism and small-size sequence valves were constructed. The newly constructed in-pipe mobile machine with a diameter of 25mm uses phosphor bronze bellows with a diameter of 8.3mm and length of 13mm. The mobile experiments show that the machine is able to lift a load of 5.9N at a speed of 1.5mm/s with an output power of 9.0mW. Also, a theoretical analysis of the mobile performance shows that the machine is able to produce a maximum output power of 120mW due to the improved conditions.