著者

土屋 喜一

出版者

一般社団法人日本機械学会

雑誌

日本機械学會誌 (ISSN:00214728)

巻号頁・発行日

vol.90, no.818, pp.10-11, 1987-01-05

被引用文献数

1

著者

土屋 喜一

出版者

公益社団法人 計測自動制御学会

雑誌

計測と制御 (ISSN:04534662)

巻号頁・発行日

vol.3, no.4, pp.294-300, 1964-04-10 (Released:2010-10-21)

参考文献数

9

著者

山越 憲一 戸川 達男 神谷 瞭 藤井 禎三 土屋 喜一

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.14, no.4, pp.296-302, 1976-08-30 (Released:2011-03-09)

参考文献数

9

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From the point of the optimal theory, the relationship between the branching structure and the mechanical characteristics of a tree was analysed in reference with such parameters as circum-ference, weight, bending moment, branch length and-branching angle, The study was based on a hypothesis that the optimal structure of a tree agrees the minimum energy loss.The total energy loss is the sum of the energy required for the construction which is proportional to the wood' volume of the branches and the energy consumption for supporting the weight of the branches and leaves which is equal to the elastic. strain energy. Results derived theoretically from the hypothesis are as follows : 1) The Maximum bending stress at each branching point is constant.2) The relation between the circurmference (C) at some point and the bending moment (T) acting on the branch is, T∝C3. 3) The relation between the weight (W) of all the parts of the tree peripheral to some branching point and C is, W∝C2.5. 4) The relation between T and W is, W∝T5/6. 5) The relatlon between the branch length (l) and C is, l2 ∝C. 6) When C0, C1, C2 are the circumferences of the mother and daughter branches and θ1, θ2 are their branching angles, the following optimal conditions for a dichotomy are derived;C02.5= C12.5+C22.5 and C13/ sinθ2=C23/ sinθ1.These relations were examined, by measuring the varying size of branches, 76-286 in all, on seven different kinds of trees, and the very good agreements between the theoreiical and actual relations were confirmed.

著者

土屋 喜一

出版者

日本油空圧学会

雑誌

油圧と空気圧 (ISSN:02866900)

巻号頁・発行日

vol.23, no.5, pp.p540-544, 1992-08

被引用文献数

1

著者

壁井 信之 小須田 昌之 鏡淵 英紀 田代 良一 水野 均 植田 康弘 土屋 喜一

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. C編 (ISSN:03875024)

巻号頁・発行日

vol.62, no.604, pp.4624-4629, 1996-12-25

被引用文献数

3

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Our aim is to develop a microactuator to be used for endoscopic surgery. The purpose of this study was to construct cylinder-piston-type microactuators that are actuated by thermal expansion of paraffin. We use a paraffin as the material for expansion because paraffin has a large coefficient of expansion in the temperature range of 35 to 45 degrees of centigrade. For smooth actuation of the piston, we must prevent the paraffin from sticking on to the inside surface of the cylinder. Thus the paraffin is enclosed in a silastic tube. The cavity between the cylinder and the tube is filled with silicone oil for lubrication and prevention of expansion loss. The outer diameter of the actuator is 2.5mm and its length is 130mm. The actuator can generate a stroke of 8mm against a load of 1kg.