TRANSACTIONS OF THE JAPAN FLUID POWER SYSTEM SOCIETY 

About: TRANSACTIONS OF THE JAPAN FLUID POWER SYSTEM SOCIETY is an academic journal. The journal publishes majorly in the area(s): Pneumatic cylinder & Actuator. It has an ISSN identifier of 1880-3121. Over the lifetime, 236 publications have been published receiving 861 citations.

Development of a Portable Pneumatic Power Source Using Phase Transition at the Triple Point

Abstract: This study is concerned with the development of a novel portable pneumatic power source applicable to self-powered mobile applications such as wearable actuator and rescue robot etc. Dry ice is chosen as a source of power for the pneumatic power source because it is nonpoisonous, easy to obtain and it expands 750 times in volume after being vaporized into gas. When dry ice is stored in the confined pressure container, it begins to liquefy after the pressure reaches the triple point (0.52[MPa(abs)],-56.6•Ž). In this process the pressure remains constant until all the dry ice melt into the liquid. When the state remains at triple point, the pressure does not decrease even though the gas is released from pressure container. By using this physical property of carbon dioxide, and by controlling the heat transfer from the surroundings into the pressure container, a noiseless, large capacity and portable pneumatic power source is developed.

A Study on a Sound Operated Valve for a Wearable Pneumatic System (1st Report: Development of a Pilot Valve of a Sound Operated Directional Control Valve)

Abstract: A sound operated directional control valve is proposed in order to widen the application of pneumatic drives to a multi-degree wearable system. The proposed valve opens and closes in response to the sound of a specific frequency propagated inside the gas supply tube and therefore needs no electric wiring to convey the control signal. By using multi-frequency sound, several valves can be controlled simultaneously and resultantly the pneumatic multi-degree wearable system can be constructed compactly. In this paper, firstly, the sound-gas pressure converter, which uses the resonance of a vibrating object consisting of a leaf spring and head, is proposed and is improved so that self-excited vibration does not arise. Secondly, the basic characteristic of the sound-gas pressure converter is investigated, and it is clarified that the back pressure is different depending on whether the sound of specific frequency exits or not. Furthermore, a pilot valve of the sound operated directional control valve is developed by combining the sound-gas pressure converter with a vibration transmitting element, which transmits the vibration in the tube to the sound-gas pressure converter. Using a Dry-Ice Power Cell developed in a previous study as the portable gas supply, the characteristic of the developed pilot valve is investigated experimentally. It is clarified that a definite change of back pressure of the pilot valve in response to the sound inside the gas supply tube can be obtained, and it is concluded that the developed valve can be used as a pilot valve of a sound operated directional control valve.

Simulation of a Pneumatic Hand Crane Type Power Assist System

Abstract: A power assist system is operated by a human operator, so it is very important to consider the human element in the control loop. In order to evaluate the performance of the power assist system in the design process, usage of simulation, which includes the human factor, is quite effective. In this study simulation of a pneumatic hand crane for work support is developed for system design. The mathematical model of the hand crane consists of the pneumatic cylinder model, link model of the crane and controller, which includes the human model, in order that the hand crane is operated passively by operation force. The validity of the simulation was examined by comparison with measurements results of the operation force and acceleration, and thus performance of the hand crane is evaluated.