著者
三宅 裕 藤井 貴広 范 秦寅
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. B編 (ISSN:03875016)
巻号頁・発行日
vol.73, no.729, pp.1167-1174, 2007-05-25
被引用文献数
2

A model for an irregularly indented rough surface has been proposed by the authors in which tall peaks are picked up and represented by hemispheres having equal volume to corresponding peak. In practical application, drag of a hemisphere is substituted by plane shear stress on a flat plate. This simplified model surface is used to simulate flow over the original rough surface. The model requires drag of a hemisphere on a flat plate. In this work, unique drag formula which is simple and acceptably accurate in balance with the compactness of the model, is investigated by numerical simulations. The formula for a hemisphere on a flat plate is deduced on the basis of simulations by RANS, of channel flows having periodically arranged hemispheres on both plates. Obtained formula is confirmed to compare reasonably to those realized by hemispheres of different size in different ambient situation, in a rough wall channel flow, though drag largely scatters. The form is applied also to pipe flows having periodic hemispheres on the wall and is found to reproduce measured friction, satisfactorily. Although the proposed idea must be examined farther carfully and should be improved in details, promising step has been set up to make proposed model a useful method in practical application.
著者
辻 裕 森川 敬信 蝶野 成臣 井前 弘幸 吉川 敏和
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. B編 (ISSN:03875016)
巻号頁・発行日
vol.50, no.458, pp.2378-2385, 1984-10-25

まず,受圧板の直径がカプセル本体の直径よりも大きい実用カプセルに対応する流体抵抗式を導いた.つづいて,加速区間におけるカプセルの走行を,送風機の性能曲線およびバイパスからの空気流出を考慮し,運動方程式に基づいて解析した.さらに,終端を閉鎖した管路にカプセルを突入させ,空気の圧縮性を利用して停止させる場合についても運動を計算した.以上の結果,計算値が実験値に満足に一致することが確認された.
著者
森脇 俊道 杉村 延広 MARTAWIRYA Yatna. Y. 蜷川 達也
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.58, no.549, pp.1674-1679, 1992-05-25
被引用文献数
20

This paper deals with an object-oriented modeling of an autonomous distributed manufacturing system and its application to the production scheduling. The architecture of the autonomous distributed manufacturing systems is discussed from the viewpoint of information processing in the manufacturing system. An object-oriented modeling method is applied to describe the decision-making activities and the communication activities of the components, such as the manufacturing devices and the workpieces. The activities of the objects are discussed in detail from the viewpoint of the production scheduling. The contents of the objects are clarified, and the part-of relations and the is-a relations between the objects are also established. A distributed production scheduling method is proposed on the basis of the autonomous decision making of the individual components and their coordinations.
著者
吉田 彰 大上 祐司 關 正憲 荒瀧 拓之 烏野 勇
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.67, no.661, pp.2961-2968, 2001-09-25
被引用文献数
4

The purpose of this study is to investigate the influence of shot peening on surface durability of sintered powder metal rollers under a sliding-rolling contact condition. The compressive residual stress, the hardness and the surface roughness of the rollers increased and the pores near the surface of those were deformed by the shot peening. The failure mode of the rollers was mainly spalling. The failure depth agreed almost with the depth where the amplitude A(τ_<yz>/HV) of the ratio of the orthogonal shear stress to Vickers hardness became maximum. The surface durabilities of the shot-peened rollers were lower than that of the unpeened roller in these experiments. While, the spalling cracks propagated from the sharp notches of the pores deformed by the shot peening. In addition, it can be considered that the shear stress below the contact surface of the shot-peened rollers increases, since the increase of the surface roughness by the shot peening results into the increase of the frictional force between the rollers. Therefore, it could follows from this that the mild shot peening without sharp deformed pore and too large surface roughness should be selected in order to improve the surface durability of the sintered rollers.
著者
彭 志新 足立 紀彦
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.57, no.537, pp.p1625-1630, 1991-05
被引用文献数
2

In this paper, the position and force control of constrafined motion of robotic manipulators is discussed. First, issues related to decoupling position and force-controlled directions are discussed. The fundamentals of estimation of the contact force without using force or torque sensors are then presented, and a control scheme for position and force control of robotic manipulators without using force sensors is proposed. The extension of this scheme to redundant manipulators is also discussed. Finally, the proposed control scheme is implemented on a 3-DOF planar redundant manipulator, and the experimental results illustrate the validity of the control scheme.
著者
河西 省司 渡辺 淳吉 諏訪 正輝
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.45, no.398, pp.1119-1124, 1979-10-25

モノレールや新交通システムに採用されている剛体電車線では,集電装置が離線しやすく,騒音が大ですり板の寿命が短い欠点がある.そこで,これらの問題点を解決する新しい集電装置を試作し,回転円板形等価実験装置を新設して各種実験し,新形集電装置と新しく開発した黒鉛分散鋳造銅合金すり板とを組み合わせた結果,騒音低減が著しく,また離線率およびすり板の寿命も現状品に比較し,格段に向上させることができた.
著者
奥井 健一 三上 房男 山根 隆一郎
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. B編 (ISSN:03875016)
巻号頁・発行日
vol.57, no.538, pp.1973-1978, 1991-06-25

The flow around two semi-infinite circular cylinders of the same diameter in the tandem arrangement at various spacings on a flat plate has been investigated experimentally. The cylinders were aligned with the axis normal to both the flat plate and the free stream. The time-mean surface pressures on the cylinders and the frequency of the vortex shedding in the direction of the cylinder axis were measured. The flow patterns on the cylinder were visualized using an oil-film technique and the flow visualization around the cylinders was performed by the liquid-parafine-mist technique. The flow patterns near the end of the cylinder were essentially different from two-dimensional flow. The flow passing along the end surface of the upstream cylinder became oscillating flow at the frequency lower than that of Karman vortex.
著者
平田 勝哉 清水 康介 福原 憲典 山内 一樹 川口 大輔 舟木 治郎
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. B編 (ISSN:03875016)
巻号頁・発行日
vol.75, no.749, pp.28-39, 2009-01-25

In this study, we deal with the tumbling, which is rotating motion with the axis perpendicular to the falling direction. Our purpose is to reveal the fundamental aerodynamic characteristics of the tumbling, experimentally. Regarding a test plate, we consider a prism with a rectangular cross section with a depth-to-width ratio λ of 0.3. The results are as follows. The reduced terminal rotating rate Ω^*, the lift coefficient C_L, the drag coefficient C_D and the lift-to-drag ratio C_L/C_D are independent of the aspect ratio AR, when AR is greater than 10. As the inertia momen ratio I^* increases from zero to 50, Ω^*, C_L and C_D increase. However, Ω^*, C_L and C_D become almost constant, at I^* greater than 50. We propose the empirical formulae to predict them. At low I^*, the tumbling shows a dominant periodicity of 360deg.
著者
一柳 健 木村 智明 長島 重和 赤坂 吉道 益田 豊次
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.89, no.810, pp.476-477, 1986-05-05

薄板圧延設備では,圧延材の長手方向の板厚精度を向上させることが最も重要な課題とされている.すなわち,板厚精度は歩留り向上の面からはもちろん,その後の深絞り加工製品精度へも大きな影響を与えるためである.この板厚精度向上のためには,圧延ロールの位置決めを行い,かつ圧延荷重を付与する圧下装置の精度,応答性の向上が不可欠であると共に,過酷な使用条件,環境に耐えうるように高信頼性,長寿命化等の改善が必要であった.この圧下装置では油圧サーボ弁が最も重要な役割を果たすが従来はノズルフラッパ式またはジェットパイプ式が使用されていた.これに対し,スプールを直接駆動する直動形油圧サーブ弁(商品名:フォースモータバルブ略称FM・V)を独自に開発し,またこのFM・Vの性能を十分発揮させるための高性能制御装置,位置検出機構等から構成される油圧圧下装置(商品名:HYROP-F)を完成させ,コールドストリップミルはもちろん,ホットストリップミル及びプレートミル等,板用圧延機の全機種に適用することに成功した.
著者
多田 幸生 小田 康正
出版者
一般社団法人日本機械学会
雑誌
最適化シンポジウム講演論文集
巻号頁・発行日
vol.2002, no.5, pp.25-30, 2002-10-04

As there are many elements to be treated at the same time in an optimum posture determination of an adaptive truss structure composed of some truss modules with variable-length members, it is difficult to solve it due to the existence of many local optimum solutions especially when not only the direction of the load but also the position of the load are constrained. So in this study, we consider the problem that determines an optimum posture of an adaptive truss structure taking account of buckling of truss members by using Immune Algorithm (IA) by which we can examine some local optimum solutions and have a high possibility for obtaining the global optimum solution.