日本機械学会論文集 C編
Online ISSN : 1884-8354
Print ISSN : 0387-5024
58 巻, 547 号
選択された号の論文の47件中1~47を表示しています
  • 鳴瀧 則彦
    1992 年 58 巻 547 号 p. 675-683
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
  • 岩田 弘, 吉田 靖夫
    1992 年 58 巻 547 号 p. 684-689
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Distributed tensioning in a wide range usually performs on a tipped saw. We studied this distributed tensioning effect analytically and experimentally using normal and tensioning disks. The following conclusions were reached. (1) Residual stress due to tensioning was measured. Residual stress distribution could be calculated by Gaussian-type isotropic additional stress. (2) Natural frequency change by tensioning treatment was calculated by the energy methed and was in good agreement with measured frequencies. (3) A backward traveling wave of the second mode determined the critical rotating speed, and the rotating speed domain above this critical point was unstable. This phenomenon was confirmed by transfer function measurment. (4) The tensioning effect increased natural frequencies and expanded the stable domain.
  • 川副 嘉彦
    1992 年 58 巻 547 号 p. 690-695
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In a governed engine, the idling speed cannot remain constant and is followed by a low-frequency noise of its own. This fluctuation of engine speed is called low-speed hunting. In order to explain analytically the mechanism of nonlinear damping force and limit cycle evolution, the previous work derived an approximate differential equation of a single-degree-of-freedom system with the closed-engine-governor loop, noting the phenomenon of very slow frequency while considering the experimental results. It gave a simple physical reasoning to the mechanism of the nonlinear negative damping force which causes an instability and a limit cycle evolution, resulting from a concept of the dynamic feedback-torque gain. The present work provides the analytical solutions of the amplitude of limit cycle, which agree well with the experimental results and the results of direct numerical integration, and which also gives insight into the effects of the various parameters of the closed loop.
  • 吉田 義樹, 伊藤 武彦, 村上 芳則, 辻本 良信
    1992 年 58 巻 547 号 p. 696-703
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Higher speed and smaller size are the tendencies for high-performance turbopumps. Under these circumstances, it is important to secure the stability of the shaft system for whirling motion. In this study, vibrations of a centrifugal impeller operating at supercritical speed are studied experimentally under the condition that the effects of shrouds and seal forces are minimized. Forward or backward whirl is observed depending on the diffuser vane angle over a wide flow range including impeller design point. These are self-excited vibrations due to the interaction effect between the impeller and vaned diffuser. Forced vibrations due to the impeller or diffuser rotating stalls are also observed at smaller flow rates, discussion on the relations between those vibrations and the pressure distribution around the impeller is presented.
  • 片岡 真澄, 大野 進一, 丸井 英史
    1992 年 58 巻 547 号 p. 704-709
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    This paper proposes a method by which calculation of the natural frequencies of bending vibration of a straight rod accompanied by an additional mass and subjected to axial compression, and the estimation the axial force based on the natural frequency are made easy. This method is an extension of Rayleigh's method. The effect of the additional mass on the mode shapes is first studied using a rigorous analysis. The deflections of the rod assumed in the calculation are modified principal mode shapes of bending vibration of a rod with neither additional mass nor axial force. Comparisons between calculated results and experimental results show that if the additional mass is lighter than about half of the mass of the rod, natural frequencies up to the third mode are obtained with good accuracy, and that estimation of the axial force is made with errors of less than ten percent.
  • 西郷 宗玄, 岩壼 卓三
    1992 年 58 巻 547 号 p. 710-715
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The balancing of a double cylindrical rotor is analyzed by modeling the system as a beam system connected by rotational spring and using the transfer matrix method. A double rotor is found to have the counter-phase-mode (CPM) vibration, which has different characteristics from the ordinal same-phase-mode (SPM) vibration ; for instance, the connecting spring influences the natural frequency of CPM, but not that of SPM. The model of the flexible disk supported type is found to have the optimum connecting spring constant to minimize the residual vibration, but the model of the double bearing type does not, which is caused by the difference in the characteristics of the CPM.
  • 兼森 祐治, 岩壺 卓三
    1992 年 58 巻 547 号 p. 716-723
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The influence of dynamic fluid reaction forces and moments of a long seal on the stability of fluid machinery was investigated. The stability analysis was carried out using a submerged motor pump in a boiler circulate, in order to explain the effect of the long seal. In the stability analysis, the individual contribution of the fluid forces and moments due to rotor conical and cylindrical whirl movements were evaluated according to logarithmic decrements. As a result, the individual contributions depend on the mode shapes of the vibration. The fluid forces acting on the long seal to conical and cylindrical whirl movements should not be ignored because they play an important role in the stability.
  • 樫本 弘, 長屋 幸助, 白石 明男
    1992 年 58 巻 547 号 p. 724-730
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    This paper presents a method for solving the dynamic stress concentration of inhomogeneous rods having two-dimensional arbitrary curvature, variable cross section and infinite length subjected to in-plane bending wave excitation. In this analysis, the exact solution of the equilibrium equations for curved rods has been obtained, and the transfer matrix, based on the exact solutions with consideration of the inertial forces has been derived. At discontinuous sections, solutions of curved and straight rods have been connected by adjusting the boundary conditions. As examples, stress concentration factors in circular, elliptical and parabolic rods with variable cross sections have been calculated.
  • 津田 吉広, 田村 英之, 末岡 淳男, 高浪 保夫
    1992 年 58 巻 547 号 p. 731-737
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The paper presents a numerical analysis of the characteristic of regular motion besides the chaotic behavior in an asymmetrical Duffing's oscillator. By making use of a computer simulation and approximate analytical method, it is shown that compared with the standard Duffing's system, the resonance curves become quite complex, and then there exist the isolated subharmonic vibrations of the 1/2 and 1/3 order, jump phenomena and chaotic phenomena in the frequency region of ultraharmonic oscillations. In addition, the system exhibits chaotic phenomena in the frequency zone of 1/2 subharmonic resonance. Chaotic behavior is discussed with regard to the Poincare mapping and Lyapunov exponent. Furthermore, the basin of attraction of chaotic and regular motions is determined by means of cell mapping.
  • 谷 順二, 宮崎 徹, 大友 規矩雄, 滝島 任, 小岩 喜郎, 大山 匡, 清水 芳雄, 高木 壮彦, 菊池 淳一, 本田 英行, 星 信 ...
    1992 年 58 巻 547 号 p. 738-743
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The left ventricle is modelled by a thick-walled spherical shell. Its forced vibration is analyzed numerically by a finite element method in conjunction with the transfer function, i.e., the ratio of the output to input amplitudes. The transfer functions obtained by experiment have single peak and double peaks during 30 and 100 Hz for a normal ventricle and the one with a regional ischemia, respectively. The viscoelastic properties of isolated canine left ventricles are identified by applying a curve fit technique to the transfer function. The dependence of the viscoelastic properties on the left ventricle pressure is investigated, too.
  • 金子 康智, 間瀬 正隆, 藤田 勝久, 長嶋 利夫
    1992 年 58 巻 547 号 p. 744-749
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    When calculating the resonant response of bladed turbine disks, it has been expedient to assume that all blades on a given disk are identical. This leads to the prediction that all blades experience the same amplitude of displacement and stresses when excited by forces harmonically related to the rotor speed. However, it has been shown experimentally that significant variations in these amplitudes occur for different blades on the Same disk. These variations arise due to the effects of mistuning, wcich refers to small differences in blade characteristics. In this paper, effects of mistuning for free-standing blades and integral shroud blades are studied by using Monte Carlo simulation and the sensitivity analysis. It is found that weakly coupled systems with small damping are very sensitive to mistuning. Also, the validity of the lumped model used in this paper is examined by comparing the calculated results with experimental data.
  • 永瀬 和彦, 北見 成紀, ト部 一誠, 大西 尚, 小林 善一郎, 藤井 宗道, 狩野 義也, 浅海 總一
    1992 年 58 巻 547 号 p. 750-756
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Most commuter trains in large cities of Japan are loaded to their full capacity in the morning rushhours. Accordingly, it takes time for the many passenngers to get on and off at the major stations where many people come in and out, and the trains are often delayed. Although the construction and performance of the commuter train doors is considered to have a great influence on the ease of getting on and off, a method quantitatively evaluating the relation between them has not yet been established. The authors proposeda new method for evaluating the above relation, and obtained a satisfactory result through practical application of the method.
  • 佐野 明人, 古荘 純次, 溝口 敦子
    1992 年 58 巻 547 号 p. 757-765
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    A superior simulator is required for the purpose of analyzing dynamic walking and developing its control methods efficiently. Especially, it is very important to model a collision phenomenon at the leg-support-exchange exactly. In this study, a 3D walking simulator in which the collision phenomenon is modeled using the Lagrangian impulsive equation is proposed. The pace gait considered in this paper is the walking in which lateral legs form pairs. In this study, dynamic control of pace gait based on motion control in the lateral plane is proposed. In the lateral motion, lost angular momentum at the leg-support-exchange is compensated by utilizing a gravity effect. The effectiveness of the proposed control method is confirmed by means of computer simulation. Finally, a reduced order model which represents comparatively well the motion of the walking system is derived by using dominant modes of the system. This reduced order model is very useful in the walking simulator and the walking analysis.
  • 舟橋 康行, 塩谷 利弘
    1992 年 58 巻 547 号 p. 766-773
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    This paper discusses the determination of grasping force and manipulating force for a 3-fingered robot hand. These forces are obtained by solving three inequalities. The solution of the inequality is parametrized and is given at once by physical constants.
  • 小泉 登男, 鎌田 実
    1992 年 58 巻 547 号 p. 774-779
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    It will be very useful for structure-borne sound problems, if energy flow of a mechanical structure can be measured. This paper, following the previous report, describes the experimental investigation of structural intensity measurement on a beam by several methods and approaches. The 2-point, 3-point and 4-point methods using an array of closely spaced accelerometers and strain gauges were compared. The results show that the 3-point method using acc, is most successful in structural measurement at the near-field. Another approach by a newly proposed reference method is also shown to be good in practical use if the vibration field is stationary. Experimental wave decomposition makes it possible to gain information of the vibration field, especially the termination condition.
  • 宮本 昌幸, 藤本 裕, 岡部 忠臣, 佐藤 栄作
    1992 年 58 巻 547 号 p. 780-787
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    New measuring methods of the wheelset angle of attack of railway vehicles on board and on the ground have been developed by RTRI in Japan. Using these methods, wheelset angle of attack has been measured on curves in the field running tests of limited express trains on a narrow gauge commercial line. The results measured are as follows : (1) The measuring accuracy of these methods attains to that which we aimed. (2) The higher the velocity and the larger the curve radius, the smaller will be the steady angle of attack. The steady angle of attack of the first wheel is 0.28 degrees, and that of the second wheel is 0.02 degrees for a curve radius of 400 m at a velocity of 110km/h. (3) The measurements and the simulation results for wheelset angle of attack are close.
  • 田中 信雄, 菊島 義弘, 黒田 雅治
    1992 年 58 巻 547 号 p. 788-795
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    This paper deals with the active control of power flow of a vibrating plate. It is the purpose of this paper to present a wave control method of a distributed parameter system such as a beam or a plate. This paper also aims to show the results of visualizing wave propagation. Unlike a conventional modal based control method, this method has the potential of suppressing all the vibration modes of a structure. First, from an analytical point of view, this paper presents three kinds of flow patterns in controlled vibration intensity; that is, (1) straight flow patterns from exciting point to control point, (2) S-shaped flow patterns, and (3) rotational flow patterns around the exciting point and control point. Then, the existence of these patterns is verified experimentally. Next, relationships between vibrational and acoustical intensity are discussed, and also the acoustic power and acoustic pressure in terms of these patterns are clarified. Furthermore, the characteristics of the rotational patterns are clarified, and a mean to generate the vortex of vibration intensity at an arbitrary position of a plate is presented.
  • 尾形 和哉, 藤井 省三, 早川 義一
    1992 年 58 巻 547 号 p. 796-803
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In the case of discrete time control for multi-input multi-output systems, if the speed of each output response differs greatly from the others, it is better to use different sampling periods with each input-output system in order to improve the robustness of the controlled system and decrease computational load. This report suggests a 2-input 2-output generalized predictive control method with multirate sampling periods. First, the description of the plant is considered. Next, the predicted future output of the each output is expressed using the multistep predictor; the cost function is then modified, and the control law is determined. The simulation result shows that our proposed method is superior to the single-rate-sampling-period method in terms of computational load, response between sampling periods, and the ease of decision of design parameters.
  • 黄 鋭, 小林 俊一, 池谷 光栄
    1992 年 58 巻 547 号 p. 804-808
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The active control system is expected to improve the characteristics of the machine actively because there is an active force subsystem which is installed on the machine in this system. However, interference (called forced pressure) between the machine and the active force subsystem existed in the system constructed by an electrohydraulic servomechanism. In this paper, we applied the model reference adaptive control method to the active control system, and discussed the pressure characteristics of the locked piston condition and the movable piston condition. The following conclusions were reached : 1) the response of the active force subsystem was improved, and the cutoff frequency reached 50 Hz, and 2) the influence of the forced pressure for the actual characteristics was reduced.
  • 呉 俊, 吉本 堅一
    1992 年 58 巻 547 号 p. 809-816
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    A flexible robot arm is designed to realize high-speed motion as a result of the lightness of its links. However, vibration of the arm caused by high-speed motion remains after motion. In this paper, a deadbeat control scheme for a flexible arm is studied in order to speed up the motion of the arm and minimize the residual vibration at the end of the motion. First, the characteristics of the deadbeat controller for the system with single input, single rigid DOF and single elastic DOF are investigated and a switching deadbeat control scheme is proposed. The response of the system with this control is compared with that when time optimal control is used. Next, this control is applied to the flexible arm with two joints and two elastic links, and several implementation problems are discussed. Finally the effectiveness of this control is confirmed by experiment.
  • 植竹 洋一, 中川 栄一, 佐藤 凖一
    1992 年 58 巻 547 号 p. 817-822
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In this paper we study the model following control of manipulators with elastic joints. In the dynamic model of manipulators, the function of the joint flexibility may be nonlinear. A simple design procedure based on the notion of Lie derivative is given. Checking of the involutivity conditions is not required. The nonlinear system will be linearized by the nonlinear state feedback and nonlinear state transformation. We show that the proposed control method can be applied to a broad class of nonlinear functions of the joint flexibility.
  • 西井 久雄, 柴谷 一弘, 鈴木 健之
    1992 年 58 巻 547 号 p. 823-828
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    This paper discusses an effective method for controlling vibration of a wheeled mobile robot. Due to its own elasticity, a wheeled mobile robot suffers from unfavorable vibration while travelling along its route, which causes undesirable positioning inaccuracies. We established a mathematical model of the 2-wheeled mobile robot. Based on this model, we designed a vibration control system using a disturbance observer in which the rotational elasticity of the 2-wheeled mobile robot is taken into account. The experimental results showed that the vibration control system proposed here is useful in practical applications.
  • 福田 敏男, 藤澤 佳生, 小菅 一弘, 新井 史人, 室 英治, 星野 春夫, 宮崎 貫志, 大坪 和彦, 上原 和雄
    1992 年 58 巻 547 号 p. 829-836
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In this paper, we describe a control method for the man-robot cooperation work type of manipulator, which is maneuvered directly by applying the intentional force to the operation control sensor (force/torque sensor) by an operator. In this control system, we designed the motion of the manipulator considering the intentional force and the interaction between the manipulator and the environment. In order to realize this motion of the manipulator, we used two impedance controllers. One is the human impedance controller, which describes the relation between the intentional force and the displacement of the manipulator. The other is the environmental impedance controller, which describes the relation between the contact force and the displacement of the manipulator. By using these impedance controllers, this manipulator can be maneuvered directly by an operator and we can control the interaction between the manipulator and the environment. We can also use thhese impedance controllers for the improvement of work efficiency.
  • 西 亮, 宮城 弘守
    1992 年 58 巻 547 号 p. 837-843
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In the 1st report, the mechanism of a wall-inspection robot which is capable of moving in a weak wind on a vertical wall was investigated. For emergency use of a wall-climbing robot, such as in rescue, fire-fighting, and so on, the robot must be able to move in strong and turbulent winds at any time. Therefore, the control system for larger wind load is important. A combined control system of a thrust force controller, a frictional force augmenter and a damper is used, and its performance is estimated by a computer simulation technique. The safety of the robot is ascertained for an actual turbulent and strong wind gust.
  • 劉 明輝, 藤堂 勇雄
    1992 年 58 巻 547 号 p. 844-850
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Exact inverse systems are not always expected for neural networks in many applications because of the output oscillation of the inverse systems. There are several sets of input signals to the neural networks, which give approximate inverse systems. In this paper, the comparisons of the learning process are first made among them by a computer simulation with a parallelogram-type robot manipulator of two degrees of freedom. It is shown that the choice of the input signals has considerable influence on its learning speed. Secondly, two learning control algorithms are proposed for applying the results of a one-layer linear neural network to the control of a direct-drive (DD) robot. The algorithms are based on preliminary learning by a one-layer linear neural network, and can be used for shortening the time of on-line learning. The effectiveness of these algorithms is demonstrated by the experiment on the control of a DD robot.
  • 黄 龍淵, 藤堂 勇雄
    1992 年 58 巻 547 号 p. 851-857
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    A learning control algorithm using neural networks is proposed for the grasping and the movement of an object by a pair of direct-drive (DD) robots of two degrees of freedom. The proposed algorithm has three feedback controllers and two neural networks. After the completion of learning, the outputs of the feedback controllers are nearly equal to zero, and the two neural networks play an important role in the control system. Therefore, the optimum setting of control parameters is unnecessary. In other words, the proposed algorithm does not necessitate any knowledge of the controlled system in advance. The effectiveness of the proposed algorithm is demonstrated by the experiment on the cooperative control of the parallelogram-type DD robots. It is also shown that gravity can be compensated by this algorithm.
  • 八重島 公郎
    1992 年 58 巻 547 号 p. 858-863
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The purpose of this study is to enlarge the range of design applicability and to improve the engagement performance by introducing a coefficient of transverse shift as a new factor in designing of crossed helical gears. Basic designing theories are first reviewed. Designing equations are newly formulated. On this basis, problems related to the engagement limit are examined. A large number of limit diagrams are then prepared. An optimal designing system is established on the basis of the theoretical study and the study of limit diagrams. The designing system and technique are tested by extensive designing computation and trial manufacture of gears. It is confirmed that the introduction of a coefficient of transverse shift is considerably effective in expansion of designing feasibility and improvement of the engagement performance. The gears manufactured for trial are smoothly engaged. The practicability is thus verified.
  • 大矢 誠, 吉村 和幸, 田村 久司
    1992 年 58 巻 547 号 p. 864-869
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    A method of inspecting an hourglass worm is newly proposed. The equation expressing the worm tooth surface involves some constants corresponding to the machine setting of the grinding wheel on a worm grinding machine. The constants differ from the design values because of machine setting error. The purpose of this method is to find these deviations. The machine setting error will be compensated and regrinding will be carried out. The coordinates of a point on the tooth surface is measured with a three-dimensional coordinate measuring machine. The observation equation is obtained from the measured coordinate. The constants can be determined from the equation by the method of least squares. This method was practically applied to worms and the deviations were found. The propriety of the method will be confirmed by regrinding.
  • 新井 典久, 青山 栄一, 杉本 豪利, 北村 正雄
    1992 年 58 巻 547 号 p. 870-875
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Reserch to elucidate the characteristics of force-fitted cylinders and gears has been carried out for several years. However, the change in the fitting surface conditions caused by force-fit has not been considered and the change in interference has been ignored. Under such a present day situation, taking up the research of fitting surface conditions caused by force-fit as the subject of the present paper, surface roughness, wear and plastic deformation of force-fitted surfaces are examined, and the actual interference during force-fitted is discussed. From this study, it is found that the decrease in interference caused by force-fit is so large as to be impossible to ignore and the interference during force-fitting changes along the axial direction. Moreover, the experimental formula, by which the actual interference of the force-fitted gear can be calculated, is introduced.
  • 田村 久司, 田中 謙吾
    1992 年 58 巻 547 号 p. 876-882
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In the manufacture of spiral bevel gears with depthwise tooth taper, there is usually a need for some "cut and try" process by which a good tooth bearing is obtained. In this paper, a method of cutting spiral bevel gears in which "cut and try" is not necessary is newly proposed. The gear is generated by a complementary crown gear, as usual, but the pinion is generated by a newly introduced "quasi-complementary crown gear". The quasi-complementary crown gear produces both crowning and profile modification to the pinion tooth surfaces. As a result, the engagement of the gears is a point-contact with a neglibibly small non conjugate. The gears made on an experimental basis showed a good tooth bearing, as might have been expected.
  • 塚本 尚久, 丸山 広樹, 三村 博
    1992 年 58 巻 547 号 p. 883-889
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    For a polyacetal with high strength and rigidity, we should select a composite polyacetal filled with, for example, carbon fiber. However, this may not be true in the case when this kind of composite polyacetal is used in water. That is, it is considered that the sliding characteristics might decrease because water enters into the bonding space of carbon fibers and polyacetal and of carbon fibers with each other. In this study, operation tests of a polyacetal gear filled with carbon fiber in water and with water drops were examined and the wear of the gear and the change of the tooth profile were determined. By comparing these results with those of an unfilled polyacetal gear, we investigated the usefulness of polyacetal gears filled with carbon fiber in water or steamy environments.
  • 中島 晃, 馬渡 俊文
    1992 年 58 巻 547 号 p. 890-895
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Combining a grit-blasted steel roller and a ground steel roller with different hardnesses, the authors examined the effect of roughness combination of mating two surfaces on the occurrence of pitting under nearly pure rolling or rolling with sliding conditions. As the results, combined effects of surface roughness and hardness related to the severity of asperity contacts and the running-in ability were recognized. When there is a large difference in the hardness between two surfaces, the roughness of the harder surface plays a dominant role. Pitting hardly occurred in the combination of a grit-blasted rough surface and a very smooth hardened surface. In the case of almost the same hardness combination, the results showed similarities to the previous results obtained using cylin-drically ground steel rollers, but the roughness effects appeared more distinctly, owing to the surface topography peculiar to grit blasting (surface with many protrusions and dents), and a decline in the running-in ability. Namely, it was shown that pitting is apt to occur on the smoother surfaces but is restrained on the mating rougher surface when two rollers with a large difference in the roughness are combined. Consequently, the pitting life became very short when the faster side roller was rough and the slower side roller was smooth, while the life was extremely long when the roughness combination wad reversed in rolling with sliding conditions.
  • 高藤 和樹, 中島 克洋
    1992 年 58 巻 547 号 p. 896-902
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The axial stiffness of a preloaded double nut is examined for preloading styles, preloading methods and various states of externally applied load. The axial stiffness under constant preloading (small value of spacing disc rigidity) separates into two groups following the direction of the external load regardless of other conditions. When the external load acts towards the preload relief, the stiffness decreases rapidly and the preload is lost just after the external force arrives at the preload value. Under the fixed position of preloading (large value of spacing disc rigidity), the stiffness varies following preloading conditions and external load positions. The maximum stiffness is obtained under the conditions of tension or compression in both the screw shaft and nuts, and the external force acts on the other side nut against the screw shaft on the supporting side. When the length of the screw shaft between double nuts becomes longer, the stiffness difference due to external load combination becomes larger as the spacing disc rigidity increases. The experimental values obtained under two representative external load conditions are slightly different from the calculated values, but their magnitude and behavior against the external load show a similar tendency.
  • 小幡 文雄, 竹平 昭暢, 松尾 浩平, 佐伯 親
    1992 年 58 巻 547 号 p. 903-909
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Though the effects of oil viscosity, which is an important factor for oil film formation, on the scoring resistance of gears have been examined, in the former studies the significant influences of specific sliding on the antiseizure capacities of lubricating oils were not taken into account. Thus, in this paper, as a basic study to establish the design for the scoring of gears, the effects of oil viscosity on antiseizure capacities of mineral base oils are examined by two-cylinder tests under various specific slidings. Though in the higher specific sliding range the antiseizure capacity rises with an increase in oil viscosity, in the lower range the effects are minute and thin oils are also applicable to the severe conditions of heavy load, higher sliding velocity, and higher bulk temperature where thick EP oils are ordinarily used. A method is proposed for applying these results to the scoring design of case-hardened spur gears.
  • 佐伯 暢人, 大矢 吉仁, 高野 英資
    1992 年 58 巻 547 号 p. 910-917
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The phenomena of 'stick-slip' oscillations in the hydraulic driving system are studied both experimentally and analytically. The system consists of a table lying on a rectilinear sliding surface, an actuator cylinder, a 4-way servo valve, a relief valve and an oil pump. In our experiment, some of the friction-velocity curves are observed to become the hysteresis curves with increasing and decreasing velocity motions of the table. Here, also in the theoretical analysis, the accelerated and decelerated portions of the friction-velocity curves are assumed to be distinct. The variations of friction are modelled as follows : (1) Kinetic friction varies with impressed electric current and sliding velocity. (2) Static friction varies with electric current passing through the servo valve and the sliding velocity. The principal experimental variables are lubricant viscosity and the mass of the table. Their influences are studied on the characteristics of 'stick-slip' oscillations.
  • 鈴木 俊男, 有浦 泰常, 梅崎 洋二
    1992 年 58 巻 547 号 p. 918-922
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In hobbing the cutter has many cutting teeth. Each hob tooth has two or three cutting edges. When a hob cuts a gear, each chip is simultaneously produced with two or three cutting edges of one tooth. Then the interference occurs among the parts produced by those butting edges, and the specific cutting forces become larger than those in orthogonal cutting. In this paper, the interference of chips is theoretically investigated. The simplest model of the interference of chips is the cutting of full-depth or non-full-depth triangular cuts. So the specific cutting forces in non-full-depth triangular cuts with a point nose straight tool are theoretically investigated with various included angles. The result shows that the specific cutting forces become large when the included angle is small. The specific cutting forces with an included angle of 90 degrees are about 1.3∼1.35 times as large as those with a flat tool.
  • 土井 雅博, 山田 三雅
    1992 年 58 巻 547 号 p. 923-930
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The generation mechanism and behavior of chatter vibration have been investigated in detail for a long time. However, very few reports have been published about the positive detection of chatter vibration. On the other hand, establishment of an objective method which can detect the commencing chatter vibration in a process and its practical method of suppression are the most important and urgent problems for automatic manufacturing systems. In this paper, a simple and practical approach is proposed to detect the occurrence of chatter vibration in a process, and its applicability is investigated. A simple and practical hardware system is constructed for development of suppression. The occurrence of chatter vibration is detected using a signal which is produced from the tool acceleration. That is to say, when the signal is over a proper stability threshold, the system judges the occurrence of chatter. Then the system attempts to suppress the chatter. Furthermore, applicability of this system to the manufacturing field was investigated. The systems was appraised and satisfactory results were obtained in this study.
  • 土井 雅博, 大橋 將宏
    1992 年 58 巻 547 号 p. 931-937
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    In this paper, the parametric vibration in machining of hard cutting metals is investigated. The vibration of this type restricts machining efficiency and accuracy conspicuously. The mechanism of vibration seems complex because of possible interactions among multiple mechanisms that cause the vibration. There have been few research activities conducted with regard to this phenomenon and applicable methods for suppression have not yet been established. Thus the parametric instability is predicted by theoretical analysis. Turning tests have been carried out for confirmation of the stability thresholds by machining of hard cutting metals. The results thus obtained art as follows : (1) There are natural frequency component and components of the chip formation in the parametric vibration. (2) The theoretical analysis for predicting the conditions of parametric instability were verified by good agreement with the results of the cutting test. (3) Parametric vibration of this type has the remarkable characteristics of low-and high-speed stabilities. (4) The regenerative vibration is excited frequently mingling with this parametric vibration.
  • 仙波 卓弥, 佐久間 敬三, 穂積 豊
    1992 年 58 巻 547 号 p. 938-944
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    This paper deals with the quantitative evaluation of cutting resistance in the finishing process of end milling to develop a computer-aided precision machining system which can control the surface profile error by varying the combination between the machine tool, tool specifications and cutting conditions. The cutting resistance generated under the finishing process of end milling is divided into cutting force, flank force and edge force through the measurement of total summed force and flank force. Also, A machining equation is developed to clarify the relation between cutting force and the removed chip area ; the flank force and contact area between the work surface and the flank face ; and the edge force and contact edge length. It is shown that the variation of cutting force, produced by the difference of work material and the progress of tool wear, can be evaluated through the specific cutting force and the force ratio between radial force and principal force. The same evaluation can be carried out on the flank force and the edge force in terms of the coefficient of friction and the specific edge force, respectively.
  • 柳本 憲作, 荻野 隆, 一宮 亮一
    1992 年 58 巻 547 号 p. 945-950
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The aerodynamic noise from a circular cutting tool was significantly reduced by using a slit tooth. By making a slit longitudinally through the tooth running parallel with a principal stream, a self-jet is caused by a slit to under the stream. A reason for the aerodynamic noise reduction is that the vortices generated behind a tooth are controlled by the self-jet. The slit tooth leads to good results in order that a circular cutting tool itself may have an effect the aerodynamic noise reduction. This paper presents the results of an investigation into the influence of the attack angle of the slit tooth on aerodynamic noise reduction by using a columnar slit tooth model. From the experimental results, the influence of the attack angle on the noise reduction quantity, the attenuation coefficient of sound pressure and the spectrum is clarified.
  • 堂田 邦明, 鵜飼 直行, 土屋 能成, 新井 透
    1992 年 58 巻 547 号 p. 951-957
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    To assess the tool-workpiece compatibility in metal forming, a friction test is carried out by a strip-ironing type tribometer, which can estimate quantitatively the effect of new surface generation during the process and sliding travel on galling. The workpiece is pure aluminum and die materials are a die steel, surface coated (TRD, CVD, PVD) steels, cemented carbides and ceramics. The compatibility is estimated through changes in the friction coefficient, observation of the frictional surfaces, and the surface appearance of products. The mechanism of galling is explained and VC, TiC and ZrO2 are estimated to have good compatibility with alminum.
  • 小尾 誠
    1992 年 58 巻 547 号 p. 958-961
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    Many techniques were proposed by means of optimization methods to verify the minimum zone accuracy. It is not always easy to obtain a true solution, even with long calculation time. In order to solve the problem, the geometrical condition of roundness is clarified. The geometrical condition is shown as follows: as shown in Fig. 1, if there are two points A, B on thhe inscribed circle determined by the minimum zone method, and another two points C, D on the circumscribed circle, segments AB and CD intersect each other. This paper proved this geometrical condition determined by the minimum zone roundness.
  • 矢畑 昇, 茅野 雅久
    1992 年 58 巻 547 号 p. 962-966
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    A plane-bending fatigue testing machine for thin sheets has been developed using a fluidic device. The machine has no mechanical moving parts and a very simple structure. Moverover, the machine is capable of repeating high frequency. As a result of performance tests, it was proved that the machine can be used to evluate fatigue strength of thin sheets.
  • 藤田 喜久雄, 赤木 新介, 長谷 宏明, 仲戸川 哲人, 竹内 誠
    1992 年 58 巻 547 号 p. 967-974
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    A hybrid-type approach for plant layout design is pressented with a constraint-directed search procedure and a mathematical optimization technique. In layout design, a plant must be arranged to satisfy spatial constraints imposed by its components. In our approach, the whole space of a plant building is divided into the finite compartments with a modular size in order to separate the description of the layout into the combinational part and the dimensional part. According to this, the approach consists of two steps. In the first step, a constraint-directed search procedure is applied for fixing the combinational relations among plant components so as to satisfy the spatial layout conditions. In the second step; an optimization technique is applied for determining the actual dimensions of compartments so as to minimize the size of a plant building considering the size of components. In the optimization, mixed-integer programming and sequential linear programming are combined and the formulation is carried out automatically from the result of the first step. This hybrid approach has been applied to the design of a nuclear power plant in order to check its validity and effectiveness.
  • 長坂 保美, 大滝 英征, 石川 義雄
    1992 年 58 巻 547 号 p. 975-980
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    When we develop and expert system, knowledge bases which were built individually can be merged easily or connected organically, and can be used effectively. We have developed a total management system for knowledge bases based on frame representation. This paper describes a method by which to represent knowledge for the mechanical engineering field and by which to manage knowledge bases with different knowledge representation, and emphasizes the effectiveness of extended functions of frame representation, system slot and inheritance. As examples, using this management system, we show the connection of an existent CAD system and an existent program "synchronized meter".
  • 本位田 光重, 西山 徳幸
    1992 年 58 巻 547 号 p. 981-986
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    A cellular manufacturing system is defined as a system which has one or more manufacturing cells. A manufacturing cell is a collection of dissimilar machines dedicated to a collection of similar parts. An important problem with the design of cellular manufacturing systems is how reasonable manufacturing cells can be constructed. This problem is considered as an application of group technology, that is, a problem of part family definition and machine assignment. A concept called group efficiency has been proposed as a quantitative criterion for a manufacturing cell formation. But, this is not a measure for a unit cell which is formed with a part family and a machine group. Thus, a new measure, that is, a "coefficient of bond degree", has been introduced for a unit cell. Manufacturing cells can be compared using a "bond degree" defined for each cell. Also, a new cell formation method based on the bond degree has been proposed, and a numerical example has been shown.
  • 渡辺 崇, 藤井 省三, 田代 明子
    1992 年 58 巻 547 号 p. 987-992
    発行日: 1992/03/25
    公開日: 2008/02/26
    ジャーナル フリー
    The authors are developing an intelligent recognizing and understanding system for mechanical drawings. This system is designed to extract the meanings of drawings and translate them into CAD data. Some of the characteristic features of the system are a module specialized in the image processing of horizontal and vertical lines and an image understanding module based on interpretation rules. To achieve a higher performance, a new parallel thinning algorithm and a rule interpreter are introduced. The thinning algorithm uses protective patterns, and it is expected to preserve corners and diverging points consisting of horizontal and verticallines. The rule interpreter is newly designed by analyzing the interpretation process for mechanical drawings. The thinning algorithm gives results with less distortion than a previous sequential thinning algorithm, and it is also applicable to the image data containing oblique lines and curves. The rule interpreter enhances the ability and the flexibility of image understanding, and it improves the interpretation result.
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