〈Original Papers〉津波避難用リヤカーに装着する圧縮空気圧によるアシスト装置の開発

巨大地震の発生に伴う大津波から避難する際に、歩行が困難な高齢者や障がい者を搬送するにはリヤカーを利用するべきである。なぜならば、自家用車では渋滞を招き、緊急車両やその他の避難者の妨げになり、被害が拡大するからである。リヤカーは、燃料が不要で、回転半径が小さく避難路のような狭い場所で有利であるなどのメリットが多い。さらに、地方では体力の弱い女性や高齢者が牽引する場合が多いので、登坂時の負担を軽減するために圧縮空気の力でアシストすることを提案する。空気圧駆動は、電気モータや内燃機関による駆動法と比較して、エネルギ保存性、価格、軽量化の点で優れている。本研究では緊急時搬送用としての機能を有したリヤカーの開発を目的として、空気圧駆動のアシスト装置を試作し、これを取りつけたリヤカーによる牽引力測定実験を実施した。その結果、アシスト装置の駆動により牽引力が70%程度に減少されることを確認した。When taking refuge from tsunami occurred by a massive earthquake, the refugees sometimes use a small car called "bicycle-drawn cart (Rear cars)" to carry elderly and/or the handicapped persons who have difficulty in ambulation. The reason is that using private cars would cause traffic jams which obstruct transfer of emergency vehicles and other evacuees. Rear-cars have many benefits such as to be required no fuel, to have small turning radius that is profitable in the narrow street like escape route for evacuees. The compressed air power-assist system is more excellent in energy conservation, cost reduction and weight saving than the system with an electric motor and/or an internal combustion engine. In this research, we made a prototype of a power-assist mechanism using compressed air which is attachable to a rear-car, and make certain of its function by the inclination climbing test. We have knowledge mentioned as below through it.(1)The target slope is 0-12%(average is 6%) incline and have 330m path length. A38l air tank is needed to climb it.(2)In carrying a person by the developed rear-car, the system need 20-100N traction power which is consistent with the theoretical value that is calculated based on the weight of a human and a rear-car.(3)The increasing of inclination generally reduces assist rates when the system employs the constant power-assist mechanism such as a compressed air. The developed system is, however, able to decrease the human traction force to 73%.(4)The assist torque was identified as 20-35Nm by each inclination which is consistent with the maximum value 34.5Nm and average value 25.6Nm obtained from simulations