著者

清水 麻衣 櫻井 宏美 久納 孝彦

出版者

日本ばね学会

雑誌

ばね論文集 (ISSN:03856917)

巻号頁・発行日

vol.2006, no.51, pp.27-34, 2006 (Released:2006-11-10)

参考文献数

8

被引用文献数

1 1

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Coil springs with rectangular wire cross section, named ‘rectangular wire coil springs’, can store more strain energy than circular wire coil springs in limited space. Therefore, they have been used mainly in press dies and other special machine tools. Recently, rectangular wire coil springs come to have different uses like suspension springs in which light weight design are demanded. On the other hand, it is necessary to reduce the number of coils by adopting the large pitch angle with improved strength of wires. However, in the stress and the spring constant formulae for rectangular wire coil springs derived by Liesecke in 1930's, the effects of the pitch angle are not considered. Therefore, as pitch angle becomes larger, the difference between the calculated results and experiment becomes outstanding. Though we have design formulae for rectangular wire coil springs of large pitch angle proposed by Watanabe et al., they are the formulation of the results by FEM analysis. In other words, theoretical derivation of the design formulae for the rectangular wire coil spring has not been performed yet. In this research, new design formulae are derived theoretically. Furthermore, the validity of the new design formulae is presented in this research by comparing the results with experiment and improved FEM analysis.

著者

渡邉 啓輔 渡辺 浩太郎 久納 孝彦

出版者

日本ばね学会

雑誌

ばね論文集 (ISSN:03856917)

巻号頁・発行日

vol.2002, no.47, pp.1-6, 2002 (Released:2005-09-21)

参考文献数

4

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Recently the downsizing and the weight saving of mechanical structures asked for springs lighter, and the light metal alloys are paid attention to as spring materials. Magnesium is the lightest in the practical metals, and it is excellent in the damping capacity. But the tensile strength and the proof stress of the pure magnesium is much lower than the ones for other spring materials. Hence, it is necessary to improve its strength by alloying, hardning, heat treatment, and by other processes. The workabilities of magnesium alloy springs had not been studied, too. Therefore the authors studied the mechanical properties of magnesium alloy AZ31 and made coil springs from wires of a magnesium alloy AZ31 by a lathe type coiling machines. The workabilities of coils were studied. The effects of annealing on the dimensions of the coils and on the spring property were also studied. The main results are as follows;(1) Magnesium alloy wire AZ31 is much inferior to other spring wires, but not much inferior in specific strength because of small specific gravity.(2) It was possible to form coil of about 5.0 in spring index from wires of a magnesium alloy AZ31 by a lathe type coiling machines, so wires of a magnesium alloy AZ31 fill the workabilities as spring wires.(3) In magnesium alloy wire AZ31 the spring back of coil diameter is large compared with other spring steel wires.(4) By annealing the outside diameter increases but the free length hardly changes.(5) When the annealing temperature is over 180(°C), the elastic limit of coiled springs deteriorates.

著者

高橋 英輝 川村 直子 久納 孝彦

出版者

日本ばね学会

雑誌

ばね論文集 (ISSN:03856917)

巻号頁・発行日

vol.2006, no.51, pp.35-43, 2006 (Released:2006-11-10)

参考文献数

14

被引用文献数

1

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Coiled wave springs (CWS) are considered as multiple layered waved washers. They are light but powerful in limited spaces. In recent years, CWS have been applied to clutches of automobiles and expected to be applied to other uses. The formulas on the spring rates and stresses of CWS have been presented by an American spring maker of Smalley Steel Ring Company, Nishio, and Japan Spring Manufacturers Association (for short, JSMA). But none of them are practical, because the accuracy is not enough. Moreover the derivations of the formulas are not clear in the case of Smalley and JSMA. It has been observed that CWS show nonlinear spring characteristics in large deflection, however, the cause has not been made clear. In this research, spring rates and stresses for CWS are analyzed theoretically. A cause of the nonlinear spring characteristics is made clear, too. Then empirical formulas on the spring rates and stresses are derived by comparing the theoretical results with experiments and FEM analysis.

著者

橋場 邦夫 寺尾 憲 久納 孝彦

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. C編 (ISSN:03875024)

巻号頁・発行日

vol.64, no.620, pp.1339-1346, 1998-04

被引用文献数

9

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The theory of squeeze film pressure and the theory of acoustic radiation pressure have been generalized to a new theory in this study. When the two fiat faces are separated by a compressible fluid film, a dynamic pressure is generated in their normal direction by the oscillation of the faces. One of the authors derived a fundamental equation for the phenomenon considering both the inertia and the viscosity of the fluid. In case of neglecting the inertia effects and assuming the isothermal change, the equation is reduced to the Reynolds equation used in the conventional lubrication theory. In this paper, an analytical solution of the Reynolds equation on the adiabatic squeeze film is presented. The results show that compressibility effects of the fluid are dominant at high squeeze numbers. The relationship between the squeeze film pressure and Rayleigh radiation pressure is also investigated theoretically.

著者

寺沢 憲 久納 孝彦 水野 正夫

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. A編 (ISSN:03875008)

巻号頁・発行日

vol.47, no.414, pp.113-122, 1981-02-25

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著者が提唱した超音波加熱による熱処理の原理は, 材料を超音波振動させた際に, 材料自身の内部摩擦により生じた熱を利用することにある. 本研究の目的は超音波加熱の実用性, はん用性を広げることにある. 材料に種々のおもりをふかし, 加熱の位置, 共振周波数などの変化を調べた結果, 材料の長さおよび加熱部の位置を任意に選ぶことが可能になった. 又, 超音波熱処理の一環として, 超音波加熱による焼きもどしを試みた.