日本機械学会論文集 C編
Online ISSN : 1884-8354
Print ISSN : 0387-5024
56 巻, 526 号
選択された号の論文の52件中1~50を表示しています
  • 小林 幸徳, 山田 元, 原田 啓一
    1990 年 56 巻 526 号 p. 1347-1351
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    An analysis is presented for the unstable vibration of a spinning truncated conical shell. For this purpose, the governing equations and the boundary conditions of the shell are derived by applying Hamilton's principle to the strain and kinetic energies of the shell. The frequency is treated as a complex value, and the variables in the equations can be written as a summation of the quasi-static components which are independent on time and the dynamic ones. The nonlinear equations governing the finite deformations caused by the spinning of the shell are solved by use of Picard's method of succesive approximation, and the linear equations on the vibration about the deformed state are solved by using the transfer matrix method. The method is applied to a spinning truncated conical shell clamped at the small edge, and the frequency parameters and the mode shapes of vibration are calculated numerically, and the behaviour of the shell on the unstable vibration are studied.
  • 小島 宏行, 桑名 秀晴, 疋田 嘉一, 水野 寿考
    1990 年 56 巻 526 号 p. 1352-1357
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    In a direct-drive robot, motors are directly coupled to the links without reduction gears, and high-grade control performance can be achieved. However, transient vibrations may frequently be generated owing to little friction and torque ripple of motors. In this report, the transient vibration characteristics of a horizontal two-link direct-drive robot are investigated theoretically. In the analysis, the torque characteristics are modeled in consideration of the torque ripple and the torque saturation characteristics of direct-drive motors, and the nonlinear state equation of the direct-drive robot is derived in consideration of the bearing elasticity of motors. Numerical simulation is carried out, and the effects of the torque ripple, the torque saturation characteristics and the bearing elasticity of direct-drive motors on the transient vibration characteristics of the direct-drive robot are demonstrated.
  • 谷藤 克也, 関 正明, 横瀬 景司
    1990 年 56 巻 526 号 p. 1358-1363
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The 1st report indicated that it is disadvantageous to the running vibration only to lower the friction coefficient of the side bearer from the present value as a countermeasure against the heavy wear of a wheel flange. This paper deals with the longituidnal elastic force and the friction one, which act in series as the resistance to truck turning, and also the lateral stiffness of the secondary spring. Generated random shapes of alignment irregularity are used in the analysis by the numerical simulation. Results shows that in the case of using the effect of reducing the lateral stiffness of the secondary spring it is possible to reduce the resistance to truck turning through the reduction of the longitudinal elastic force without deterioration of the riding comfort under both good and poor conditions of track irregularity.
  • 谷藤 克也, 永井 健一
    1990 年 56 巻 526 号 p. 1364-1370
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The body-bending vibration of a bogie car is analyzed with two calculation models : one the exact model based on the theory of beam and the other the 1-mode approximation model in which only the fundamental mode is taken into consideration. First, the frequency responses calculated with the two models are compared to investigate the effects of the higher bending modes on the whole vertical vibration of the car body. These car body acceleration curves are transformed to the acceleration PSD through a formulated track irregularity PSD and compared with field test data to verify the calculation models. Then, the applicability of the conventional 1-mode approximation model to the quantitative examination is estimated in the range up to 100 Hz, where 4 modes of the car body bending are included.
  • 信川 寿, 国方 衛, 真鍋 芳嗣
    1990 年 56 巻 526 号 p. 1371-1376
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The transient response of the truck crane structure due to winch operation when the loading beam is operated in the vertical direction from the crane frame axis has been examined by modal analysis. The transient vibration strain in the lower beam were observed in an actual track crane and numerical simulations were carried out. Then, relationships between the winch operation and transient vibration strain levels were presented for the various operation patterns of the winch.
  • 藤田 隆史, 中嶋 一史, 杉本 一, 世古 泰朗, 小見 俊夫
    1990 年 56 巻 526 号 p. 1377-1380
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    A seismic isolation floor using a new mechanism to achieve high performance in vertical isolation, was developed. The floor was a partially 3-dimensional isolation floor in which a vertical isolation table was incorporated in a horizontal 2-dimensional isolation floor. The table was suspended from pulleys by wire cables which were connected to coil springs installed horizontally. This mechanism was used to convert vertical movements of the table into horizontal deformations of the springs, and made it possible to provide the table with a very low natural frequency of 0.5 Hz or so. Excitation tests were carried out for an experimental model of the floor on which a computer component was mounted. Through the tests, it was confirmed that the floor had excellent performance in vertical isolation as well as in horizontal isolation. Analytical models for the horizontal and vertical responses of the floor were supported by the experimental results.
  • 高津 宣夫, 伊藤 耿一, 遠藤 紘, 田中 晃, 加藤 正名
    1990 年 56 巻 526 号 p. 1381-1385
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Free-free beams excited at the center are commonly used as the specimens of the measurement of damping performance of sheet materials. The antiresonances appearing in the driving point transfer function of the free-free beams are studied, and it is shown that resonance modes of a cantilever beam of a half length is observed at the antiresonances. The damping ratio estimated from the antiresonance trough is compared with the one evaluated from the resonance peak introducing a lumped parameter system. They coincide if the damping is assumed to be hysteretic, which agrees with the experimental results on a composite steel sheet with a viscoelasitc core layer.
  • 安田 仁彦, 葉 建瑞
    1990 年 56 巻 526 号 p. 1386-1393
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    In a previous paper, a new nonparametric method for the identification of nonlinear single-degree-of-freedom vibratory systems was presented. In this paper, the technique is generalized so that it can identify multi-degree-of freedom vibratory systems, among which are those with their restoring or damping forces dependent on both displacements and velocities. The main procedure of this technique is to divide the regions of displacements and/or velocities into small subdomains and express the restoring or damping forces by interpolating over each subdomain. Some numerical examples are given, and the technique is shown to be valid.
  • 永井 健一, 渥美 全弘, 杉山 晋一, 長屋 幸助, 谷藤 克也, 武田 定彦
    1990 年 56 巻 526 号 p. 1394-1399
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper presents analytical results of non-linear vibrations of a traveling beam levitated by magnetic forces. The problem is modeled as the Euler-Bernoulli beam with a variable cross section supported by non-linear springs. The beam and the springs move on an undulated line. Introducing a new mode shape function which is expressed as the product of the trigonometric function and the power series truncated to the fourth order and utilizing the galerkin procedure, basic equations are reduced to the coupled non-linear equations. The steady state solutions of the beam was obtained using the harmonic balance method. It is found that the non-linear responses show the type of soft-spring, the unsymmetric support of the spring or the unsymetric cross section to the mid-point of the beam show large amplitude vibrations of a rotating motion and that of a translating motion in relatively large frequency range.
  • 浅見 敏彦, 関口 久美
    1990 年 56 巻 526 号 p. 1400-1407
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Air damper has a great advantage that is independent of temperature change. This paper proposes an analytical approach for designing air damper with a piston and a cylinder. The characteristics of the air damper are depend on the properties of air : viscosity and compressibility. Thus, the air damper shows the so-called visco-elastic property : the applied force to the piston is resistant to the velocity and displacement of the piston. As a result, the air damper has two important factors, called damping coefficient and spring constant. Two types of air damper are discussed. Type I is a viscous damper whose resisting force is proportional to the piston velocity, and type II is a nonviscous damper whose resisting force is proportional to the velocity-squared of the piston. This paper leads to a simple and accurate method for designing these types of air damper.
  • 臼井 清一, 谷 和男, 白井 信正, 堀内 英一
    1990 年 56 巻 526 号 p. 1408-1413
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper describes a mathematical model of an uneven road surface where the statistical characteristics of the roughness are isotropic. A spectral density matrix is obtained in consideration of a correlation of the roughness between the right and the left track. By factorization of the rational spectral density matrix, which results from the approximation of the cross spectral density, the transfer function matrix is formulated, and the minimal realization of the shaping filter is obtained analytically. The results of the numerical simulation using the shaping filter are in good agreement with analytical ones.
  • 遠藤 満, 井上 雅彦
    1990 年 56 巻 526 号 p. 1414-1419
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The rolling noise of the wheel/rail system of a railway vehicle was investigated. First, the coupled vertical vibrations between a rail and a wheel were analyzed, regarding the rail as an infinitely long beam installed on an viscoelastic foundation and the wheel as a point mass. The surface roughness of the rail was considered and the contact characteristic between a rail and a wheel was linearized by using the equivalent linearization method. And by obtaining the frequency response functions for the rail and the wheel, those vertical vibrations were calculated. Then, on the basis of the acoustic model that the point sources are infinitely arrayed on the top and the lower part of the rail, the sound generated from the rail was calculated. The trend of the theoretical results for the sound pressure level agreed with the experimental results using the Shinkansen and the hypothesis that the main source of the rolling noise is the rail was ascertained.
  • 古村 義彰, 平松 力, 新谷 真功
    1990 年 56 巻 526 号 p. 1420-1424
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    If the source point of sound is found and reinforced, the vibration and the noise of a machine can be reduced. The delay time between the sound waves which arrive at two microphones is measured by using an FFT analyzer. From the delay time, the difference in the distances from the sound source to the two non-directional microphones is decided and the source is described as a point on a hyperbola. When one of the microphones is moved from d point to the other two points, other hyperbolas are found. The source point is thought to be the intersection of these hyperbolas. As some delay times are found in the cross correlation of these sounds which is the single sinusoidal wave, the differences in the distances are of several classes. Many intersections of three group hyperbolas exist. The center of the nearest points in these intersections agrees well with the sound source which is a loud speaker. This method can give the point of a sound source more simply than sound intensity method.
  • 和田 仁, 小林 俊光, 立崎 寿
    1990 年 56 巻 526 号 p. 1425-1430
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The dynamic characteristics of the middle ear with an eardrum perforation are different from those of a normal eardrum, because the aeration of the external auditory canal to the tympanic cavity is not blocked in the case with an eardrum perforation. Therefore, the dynamic characteristics of the middle ear with an eardrum perforation are measured with a newly developed measuring apparatus, and the equation corresponding to the output of the apparatus is induced. The measurement results and the numerical ones are compared, and the effects of each part of the middle ear upon its dynamic characteristics are clarified. Finally, the relationship between the perforation area and the value of hearing loss is obtained theoretically.
  • 和田 仁, 小林 俊光, 長沼 広, 立崎 寿
    1990 年 56 巻 526 号 p. 1431-1434
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Eight temporal bones were extracted from fresh autopsy cases, and the attachment of the eardrum to the temporal bone was examined. Then the dynamic characteristics of the eardrum of the specimen were measured by means of a newly developed measuring apparatus. At the same time, through application of the impedance theory of the tube to the external auditory canal and the energy method to the eardrum, the equation corresponding to the output of the apparatus was obtained. Comparing the measuring result and the numerical result, the adult average values of Young's modulus EE, thickness hE, and damping ratio ξE=cE/2(mEkE)1/2 were determined to be EE=3.2×107 N/m2, hE=0.1 mm, and ξE=0.2.
  • 和田 仁, 小林 俊光, 目時 哲郎
    1990 年 56 巻 526 号 p. 1435-1439
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Nearly four years ago, a ceramic artificial auditory ossicle, which was said to be superior to the plastic one with respect to affinity and biocompatibility, was put on the market. However, the configuration of the ceramic artificial auditory ossicle was determined only by the easy of insertion when the surgical operation was performed, and the dynamic consideration was not taken into account. In this paper, an attempt is made to determine theoretically the optimal configuration of the columella-type ceramic artificial auditory ossicle from the standpoint of dynamics. The middle ear mechanical properities obtained from the measurement of the middle ear dynamical characteristics are used for the numerical calculation.
  • 島地 重幸, 松本 政悦
    1990 年 56 巻 526 号 p. 1440-1443
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    In fine finger operations, we cannot neglect the deformation of the finger surfaces. The position and the direction of the force affecting the finger surfaces should be researched if the deformation of the finger surface is large like as those of the operations of small objects and of objects that have some line edged corners. This study measured the force acting between soft rubber and a bent aluminum plate and qualitatively discussed the friction zone, a fanwise zone where the line of acting force can be located. It a clarified the characteristics of large deformation : (i) the nominal coefficient of friction becomes large on the shake of a plunge effect and (ii) the friction zone departs from the line-edged corner.
  • 田川 善彦, 山下 忠
    1990 年 56 巻 526 号 p. 1444-1448
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The study of kinematic characteristics of robot manipulators is evolving new approaches to the link mechanisms having many degrees of freedom. The manipulability of a robotic hand was proposed recently to measure the working effectiveness of distributed multiple actuators; the algebra of the spatial vectors, as another example, resembles closely mathematical quantities called screws and motors, which are used extensively in the kinematics. These approaches are applied to bipedal locomotion in this paper. The results suggest that they are useful to further developments of legged robots and to found a theoretical framework for the robotic link mechanisms in general. Also the joints in the link mechanisms are classfied into three types from the kinematic viewpoint : active, passive, and zero moment joints.
  • 石原 正, 亀山 裕史, 竹田 宏
    1990 年 56 巻 526 号 p. 1449-1454
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Digital controllers for trajectory control of a robot arm are proposed in this paper. A simple discrete-time model of the robot arm obtained by an Euler approximation is used for the design of the controller. Disregarding computation delay in the controller, we derive an algorithm based on the computed torque method. The feedback gains can easily be determined to obtain desired closed loop poles. Using a state predictor, we modify the algorithm so as to take account of unit computation delay. A simulation example shows that the modified algorithm provides better performance for the high gain feedback case. In addition, for the robot arm stabilized by the modified algorithm, we propose a design of an iterative learning controller. The proposed controller consists of a simple error-correction algorithm and a series compensator of FIR type. A simulation example is presented to illustrate the performance of the proposed iterative learning controller.
  • 小笠原 昌和, 原 文雄
    1990 年 56 巻 526 号 p. 1455-1461
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The motion of a robot manipulator submerged in water is strongly affected by fluid forces, and it is an important technique to avoid their influence on the motion of an aquarobot manipulator to achieve highspeed, precise motion. This paper deals with extension of the technique of air bubble ejection from the manipulator surface, i. e., investigates the mechanisms of reduction of drag force by air bubble ejection and effects of air bubble ejection on the control of the aquarobot manipulator. Using a two-degree-of-freedom and two-joint manipulator, experiments were performed and the following major results were obtained: (1) There exists a particular pattern of air bubble ejection for reduction fluid drag force acting on the manipulator and it resulted in reduction of drag force by 25 % compared to that for no air bubble ejection. (2) There exists a particular pattern of air bubble ejection that brought a 40 % reduction of the control torque required for compensating the fluid drag force. (3) The major mechanisms for drag force reduction were found to be the controlled flow pattern around the manipulator formed by ejecting air bubbles. However, it is noted that these effects of air bubble ejection were dependent on the mode of manipulator motion.
  • 古荘 純次, 長尾 裕史, 成瀬 誠
    1990 年 56 巻 526 号 p. 1462-1469
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Flexibility of driving systems produces robot arm vibration. Since vibration decreases the operation efficiency and quality, the prevention of such vibration becomes an important consideration in robot arm control. High-gain feedback of distortion in driving systems at each joint improves the oscillatory behavior of the robot system. By using a theory of multivariable root-loci, we present two propositions on the behavior of the closed-loop eigenvalues when the high-gain feedback of distortion is implemented.
  • 福田 敏男, 中村 知己, 田中 隆康, 江刺 正喜, 庄子 習一
    1990 年 56 巻 526 号 p. 1470-1474
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Since micro manipulation is necessary for handling micro order small objects, actuators suitable for a micro manipulator have long been studied. Unlike the conventional actuators, this paper proposes a new electro static actuator with three degrees of freedom for this purpose. Because the tip of a micro manipulator needs multiple degrees of freedom, the proposed actuator can give three DOF, so that the micro manipulator can be improved to accomplish versatile skilful motions. The silicon based micro probe sensible to applied forces is attached at the tip of the actuators. Three modes of motion at the tip of the micro manipulator are demonstrated experimentally. Thus the proposed actuator demonstrates the feasibility of the micro actuator for the micro manipulator.
  • 福田 敏男, 細貝 英実, 菊池 勇
    1990 年 56 巻 526 号 p. 1475-1480
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper reports the key features of a new type of actuator based on shape memory alloy (SMA) and its application to mechanisms of underwater mobile robots. The proposed actuator consists of several modes of SMA, so that any shapes can be produced as the synthesized sum of excited modes, like the mode expansion and synthesis. Thus, the actuator shows the characteristics of the distributed parameter type of actuators with a specified number of modes. In this paper, the following aspects are described: (i) A flat-belt type of SMA is employed and its bending characteristics are examined. (ii) A synthetic method of wave forms is presented. (iii) Applying the proposed distributed actuators to the underwater mobile robot, mechanisms such as fish fins are shown to obtain thrust forces in the water. (iv) The shape of the actuator is experimentally verified to be similar to the computed shape, as expected. As a result, the proposed distributed actuator shows the possibility of applications to distributed parameter shape control.
  • 高橋 史明, 中村 茂, 谷 順二
    1990 年 56 巻 526 号 p. 1481-1487
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper presents a theoretical study on the dynamic stability of a cantilevered pipe conveying fluid and the active control to stabilize it. The active control force is derived from the bending moment produced by a piezoelectric actuator partially attached to the pipe. The equation of motion is reduced to a finite-degree-of-freedom system by Galerkin's method. A control law is determined using the eptimal-regulator theory. It is shown that in the case where fluid is drawn in from the free end, the mass and rigidity of the actuators has an opposite effect on the dynamic stability of the cantilevered pipe to the spouting case, Moreover, the optimal location of the actuator and effects of error in the mass and rigidity of the actuator on the stability of the control system are discussed.
  • 末広 利範, 大川 不二夫, 黒須 顕二
    1990 年 56 巻 526 号 p. 1488-1493
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper describes the application of a Model Reference Adaptive Control System (MRACS) to the speed control and the position control of a DC servo system and a Direct-Drive (DD) servo system with a flexible transmission element. The servo systems are simply modelled as a servo mechanism with a one degree of freedom oscillatroy load. After inducing the discrete-time mathematical models of the servo systems for the speed and position as a lumped parameter system, the discrete MRACS with a simple algorithm and structure is designed for each discrete model. A set of experiments has been carried out to examine the effectiveness of the MRACS. A rotary encoder was used to measure the speed and the position of loads in the experiments. Experimental results have shown that the control performance is good and the constructed MRACS is effective.
  • 相良 慎一, 大川 不二夫
    1990 年 56 巻 526 号 p. 1494-1498
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper presents position and vibration control methods of a crane in the air and under the water. In general, dynamic characteristics of a crane are changed by a load, hoist motion and other factors. In addition, they have many unidentifiable parameters under the water. We use a model reference adaptive control system (MRACS) as our control policy. Using a discrete time model, we can design a discrete MRACS by simple algorithms and structures. The experimental study has been carried out using a crane composed of a linear pulse motor for the traverse motion and a small pulse motor for the hoist motion. A CCD camera and an image processor are used to measure the position of the load. Experimental results have shown that the crane in the air and under the water can be controlled effectively by the proposed adaptive algorithms.
  • 松下 尚史, 則次 俊郎, 和田 力
    1990 年 56 巻 526 号 p. 1499-1504
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    It is important to improve both the ride quality and the driving stability of vehicles. However, with conventional passive suspensions, these two requirements can rarely be simultaneously satisfied. In this paper, an active air suspension is constructed using a pneumatic cylinder and two electro pneumatic proportional pressure control valves, which has the advantage of inherent buffer function due to the air compressibility. However, an electro pneumatic control valve involves a considerable delay time which deteriorates the vibration control performance. To cope with this problem, the control valve delay is formulated as an input time delay in the discrete-time state equation, for which an optimal regulator with a state observer is designed. Through experiments, the applicability of this optimal control method for the active air suspension can be confirmed.
  • 小島 宏行, 根津 紀久雄, 坂本 賢治, 川鍋 隆, 小島 英男
    1990 年 56 巻 526 号 p. 1505-1510
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    A rapid position control method, to which the feedforward control based on the inverse dynamics is applied, is presented, and the availability is confirmed experimentally and theoretically. In the experiment, the linear direct current motor is made with an aluminum coil frame or an acrylic resin frame. Then, it is confirmed that, by the present control method, the moving part of the linear direct current motor can be controlled exactly to the position control command for an arbitrary settling time, without undesirable mechanical vibrations. When the settling time is comparatively long, the wave shape of the control current of the motor is affected mainly by the spring force of the beam. Then, with a decreasing value of the settling time, the inertia force has significant effects on the wave shape of the control current. Furthermore, the numerical simulation results obtained by the finite element method agree well with the experimental results.
  • 川副 嘉彦
    1990 年 56 巻 526 号 p. 1511-1517
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    As a step toward the goal, i. e., the establishment of racket dynamics and the proposal of an improved evaluation system for optimum design, the effects of the support conditions of grip and the gut strings on the dynamic characteristics of the two different type of rackets are investigated using experimental modal analysis. The results show that the damping ratio and the decay rate of each mode are much greater and the damping of each mode scatteres wider under the grip constraint condition than those of free-support, and also show that the gut strings contribute very little to the modal parameters within the freguency ranges of 600 Hz, in which no membrain modes appear, but the damping is very small relative to the time during the ball/racket impact and the acceleration is large even in high-frequency modes. Accordingly, it may be safely assumed that the higher modes and the magnitude of acceleration are responsible for the stability of hitting surface.
  • 横山 正明, 河上 恵三
    1990 年 56 巻 526 号 p. 1518-1523
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Since the development of the revolutionary SKETCHPAD system developed by Ivan E. Sutherland, many works have been done on the automatization and systemization of machine design and machine draughting processes through the application of computers. At present, computer draughting is well established and most widespread in industry. However, the representation remains strictly two-dimensional and the computer has no understanding of the three-dimensional geometry or the physical properties of the object which lies behind the drawing. Not a few works have been done on the understanding and construction of polyhedral objects from usual orthographic three views. However, these works cannot be applied to the drawing of mechanical parts, because real mechanical parts are composed of curved surfaces as well as flat ones. In this paper, we present an algorithm which can represent all solid objects with curved surfaces satisfying orthographic three-view drawings. The algorithm for the construction of polyhedral objects is modified by introducing the cubic Bezier curves and the bicubic Bezier surfaces. This new algorithm has been implemented and has functioned well on complex objects with curved surfaces.
  • 深田 悟, 神谷 嘉則, 下町 多佳志, 水町 豊, 久家 誠
    1990 年 56 巻 526 号 p. 1524-1529
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    A linearlized model considering the effect of eddy currents is shown to be useful for the analysis of the dynamics of active magnetic thrust-bearings, in which electromagnet cores are composed of solid steel. The dynamics of a magnetic control-force is modeled by the first-order time-lag system with unknown parameters : a gain and a time constant. The parameters are estimated from experimental results : the static relation between coil current and magnetic control-force, and the frequency response of the magnetic flux for input to a power amplifier. The effect of eddy currents on the dynamics is confirmed by the frequncy response of the flux for coil current. Model simulations with estimated paramneters are compared with experiments in frequncy response and impulse response. The results show the effectiveness of the linearlized model.
  • 長屋 幸助, 武田 定彦, 佐藤 淳, 井関 重男, 関口 肇, 斉藤 登
    1990 年 56 巻 526 号 p. 1530-1534
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper proposes a thrust bearing lubricated by a magnetic fluid under a magnetic field. The critical pressures of the bearing versus the magnitude of the magnetic flux densities have been investigated experimentally. It is clarified that the critical pressures of the proposed bearing are larger than those of the normal lubricant bearing under high speeds.
  • 新野 秀憲, 中西 正治, 伊東 誼
    1990 年 56 巻 526 号 p. 1535-1541
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The design procedure generally consists of many processes, from concept design to the release of parts and assembly drawings. Over all these procedures, designers always analyse various design requirements and conduct the information processing so as to have the most suitable result. Consequently, to rationally automatise such a design procedure, it is necessary to effectively process the design and its related information, e. g., decision making, by the computer system. In this paper, therefore, to establish a future CAD system of artificial intelligence type, the decision making in the basic layout design process of machine tools has been investigated and a decision making method using the multi-dimensional evaluation vectors has been proposed. The validity of the proposed decision making method has also been verified through the development of a system for selecting the suitable bearing type and arrangement for the main spindle bearing system from many candidates.
  • 両角 宗晴, 岸 左年
    1990 年 56 巻 526 号 p. 1542-1547
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    A study of the mechanics of a new type South-Pointing Chariot with the differential gear train of the external spur gear was conducted. Firstly, the pattern of this differential gear type South-Pointing Chariot is replaced with the combined planetary gear system in which two simple planetary gear trains are connected. Secondly, through a theoretical analysis, it is confirmed that power circulation occurs in the system. Thus the principle that fulfills the fundamental function of the South-Pointing Chariot is explained. Thirdly, an experimental design and manufacture of the new type South-Pointing Chariot is carried out. The theories in this analysis are verified by a practical test run of the Chariot.
  • 塚本 尚久, 丸山 広樹
    1990 年 56 巻 526 号 p. 1548-1552
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Worm gears, which undergo a great deal of slipping, produce a large amount of heat and suffer from a high degree of wear, being low in resistance to heat and wear. However, plastic worm gears are currently demanded for use in food processing equipment which should be free of oil getting into products. In the hope of developing practical morm gears from composite plastic material filled with fiber and solid lubricants, worm gears made of such plastics are produced and tests are callied out to determine degree of wear, coefficient of friction, surface roughness and changes in temperature.
  • 庄司 彰, 川島 義一
    1990 年 56 巻 526 号 p. 1553-1558
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The first paper described the manufacture of injection-molded and the static capacity test of plastic magnetic gears. The second paper describes the results of dynamic test. (the noise test, wear test and measurment of temperature of plastic gears teeth) As regarding preventive gear noise, pastic magnetic gears are superior according to the results of the experiment. Those gears show a great deal of wear when the gears are used with no lubrication, but little wear when grease and oil lubrication was appplied. It was possible to put the injection-molded plastic magnetic gears to practical use in this experiment. During the temperature rise of the plastic gear teeth, both the measurements and authors' calculation formula to deal with viscoelastic materials were compared. The two values agreed with each other. The value of temperature rise was only slight within the load of the magnetic force level. It was possible to put the injection-molded plastic magnetic gears to plactical use in this experiment.
  • 白石 彦一, 鎌田 治
    1990 年 56 巻 526 号 p. 1559-1563
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Vibration and noise can be reduced when one of a crossed helical gear pair is made of plastics. Because of the large stress due to the theoretical pointcontact and of the large relative sliding velocity between involute helical gear flanks, the plastic gear wears easily, and is therefore only used for the light load to ward off severe wear. The allowable load should be increased in the case of theoretical line-contact; hence, the study on such a tooth profile was carried out. It is assumed that the shaft angle is 90°, one of the pair is an involute steel helical gear of perfect wear-resistance, and another is a plastic gear which has a tooth profile transferred from the steel gear. The transferred profile is an envelope of the steel tooth flank moving relatively to the fixed plastic gear. The profile depends on the helix angle, and agrees well with the experimental results.
  • 藤井 正浩, 小幡 文雄, 吉田 彰
    1990 年 56 巻 526 号 p. 1564-1569
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The influence of tip relief on the approach side on the working flank bulk temperature, which has an intimate relationship with scoring occurrence, was studied taking the change of dynamic load into account. The amount of tip interference may be estimated well by Weber and Banaschek's formula for tooth deflection. The working flank bulk temperature is affected more by the change of dynamic load due to the tip relief than by the tip interference. The amount of the tip relief on the approach side and the range of the tip relief should be determined taking the influence of the dynamic load on the working flank bulk temperature into consideration.
  • 綿貫 啓一, 丸山 一男, 大滝 英征
    1990 年 56 巻 526 号 p. 1570-1575
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Recently, the fine positioning system has come to be used in the mechanical industry, and has required improvement of positioning accuracy, reduction of positioning time, increase of carrying capacity and so on. However, the existing control method for the positioning stage may cause delay of phase response or residual vibration when disturbance or overweight acts on the system or stage drives at a high speed. In order to obtain the optimum control inputs, it is necessary to grasp the dynamic behaviour of the system exactly. This paper deals with the transient response of the positioning stage using the linear graph theory which has been reported previously. The simulated results are compared with the experimental ones, and they are found to be in good agreement. Through these studies, it is concluded that this method is useful in analysing the dynamic behaviour of a positioning system.
  • 川名 武, 小島 東作, 倉橋 恭子
    1990 年 56 巻 526 号 p. 1576-1579
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    To keep pace with multipin semi-conductors or high-density circuit boards, the automated bonding technique for very fine insulated wires is required. One of the important subjects needed to be solved is to prevent the thermal damage of the insulation when a ball for bonding is formed. By computer simulation using the finite element method, we have found that cooling by heat conduction through a metal chuck held near the ball, or forming a ball in a short time is extremely effective.
  • 竹内 聖, 佐藤 和郎
    1990 年 56 巻 526 号 p. 1580-1583
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Up to the present, glass has been cut by snap processing or grinding processing using a diamond wheel. Especially when a glass plate is cut into a circle, grinding processing is the main method. But the method requires a lot of time and energy, and, worse, makes a lot of noise. Thus a new method by means of local compression was used to cut the glass plate into a circle. This report refess to that method. The following's understood: 1) Only compression makes it possible to cut a glass plate into a circle. 2) Cutting by compression requires less energy and time. 3) Almost all parts of the cutting section achieve a mirror finish.
  • 河村 忠治
    1990 年 56 巻 526 号 p. 1584-1587
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The fastening of a lap joint is used in a petal flange with round hole, the shape of the hole edge is transformed round into square as press-fitting force increases. In such a case, reduced to the accuracy and strength of the joint, and an expedient to correct these defects with restrained the hole edge in the jointpiece during fastening. This report provides a comparative study of the fastening characteristics of lap joint with consciously converted to the square hole from the round hole. As a result of investigation, fasten the joint without restraint to be changed an initial shape of the hole edge, thereby the crushing strength is not elevated. But, rotational strength of the joint is fairly improved with that object in view a very useful fastening method.
  • 長屋 幸助, 武田 定彦, 永井 健一, 佐藤 淳, 杉浦 光則, 佐川 竜一郎
    1990 年 56 巻 526 号 p. 1588-1591
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper proposes a two-dimensional displacement sensor which is available to detect high speed phenomena such as high frequency vibrations. The sensor consists of a laser, polarisers, a beam splitter, solar cells and clean plates in which an index of double refraction varies in one direction. Since the clean plate as just mentioned has not been produced, this paper applies thin films sandwiched with a magnetic fluid, and the double refraction is generated by using permanent magnet. In this system, the laser beam propagating from the moving body is divided into two beams by a beam splitter, and the divided beams pass through the two clean plates whose refraction axes are in right angles with each other. An intensity of the laser beam after passing through the clean plate is detected by a solar cell. Then the position of each beam is decided by the intensity of the laser beam. Experimental tests have been performed to verify the principle as just mentioned.
  • 清水 伸二, 李 和樹, 西田 浩次郎
    1990 年 56 巻 526 号 p. 1592-1596
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Dynamic balancing is one of the key technologies in the realization of high-speed machining. In the field of grinding, some automatic balancers have been developed and manufactured. These balancers, however, will not be applied to high-speed spindles, because of their mechanisms. In the present paper, a basic mechanism of the balancer for high-speed cutting machines is proposed. That is, this balancer has four chambers on the periphery. Flow of compensating liquid from the center pocket to the chambers is controlled by the movement of an inner weight due to centrifugal force. A prototype is manufactured and the function of the proposed mechanism is evaluated. As the result of the tests, it is clarified that the balancing mechanism proposed in the present study is available for the use of high-speed spindles.
  • 柴坂 敏郎, 豊島 敏雄, 藤田 正彦
    1990 年 56 巻 526 号 p. 1597-1601
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper deals with the experimental examinations on the machining accuracy in the micro end mill operations. The rigidity of the micro end mill is very low, so that it is deflected by the decrease of the clearance caused by the tool wear of the cutting edge. When the tool wear becomes large against the circumferential form relief, the end mill is deflected further by the contact between the workpiece and the flank face of the tool. The measured radial cutting force becomes very large because of the tool deflection, and in some case, the tangential cutting force changes into negative value. Then, it is found that the machined surface error increases with increase in the deflection due to the wear of the end mill, and that the width of machined groove decreases due to the tool deflection.
  • 柳本 憲作, 荻野 隆, 一宮 亮一
    1990 年 56 巻 526 号 p. 1602-1607
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    The purposes of this study are to reduce the aerodynamic noise from a circular cutting tool. By making a slit longitudinally through the tooth, a circular cutting tool itself has effect on the aerodynamic noise reduction. A reason of the aerodynamic noise reduction is that the vortices generated behind a tooth are controled by a self-jet from a alit. The self-jet generated from a slit is much influenced by tooth spacing of a circular cutting tool. This paper presents the results of an investigation into the influence of the tooth spacing on the aerodynamic noise reduction using the slit tooth. The influence of the tooth spacing on the attenuation coefficient of sound pressure and St number is clarified from the experimental results.
  • 武内 浩一, 西村 剛徳, 稲崎 一郎
    1990 年 56 巻 526 号 p. 1608-1613
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Diamond is the ultimate material for cutting tools, insulators, heatsinks, semiconductors, and protecting films etc. because of its superior characteristics. The application of diamond has been mostly limited to cutting tools so far because natural diamonds or diamonds deposited at high pressures are particles with limited size. Recently, however, diamond has been deposited in the vapour phase and it has been possible to coat some materials with diamond. In this study, special attention is paid to the surface properties of the substrate which have an effect on the nucleation of diamond in the vapour phase. The nucleation mechanism is investigated from the view point of substrate surface states and substrate material.
  • 井上 光弘, 原 泰啓, 笹田 直
    1990 年 56 巻 526 号 p. 1614-1619
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    In order to examine the effect that metal powder used as an automotive brake lining exerts on fade resistance, shearing force was applied to the cured phenolic resin powder, to which various kinds of metal powder were added. Thereafter, solvent extraction was carried out, and the molecular weight distribution of the extracts was measured. Moreover, the fade resistance of the friction pads, to which various kinds of metal powder were added, was measured with a braking device dynamometer for test pieces. As the results in the mechanochemical degradation of cured phenolic resin due to shearing force, it was found that metal powder had the catalytic action to decrease the average molecular weight of the degradation products. In addition, it was found that this catalytic action differed according to the kinds of metal powder, and there was correlation between the order of these catalytic actions and the order of the fade resistances of the friction pads using respective kinds of metal powder.
  • 日野 裕之, 大園 隆一, 塚本 頴彦, 佃 和弘
    1990 年 56 巻 526 号 p. 1620-1625
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Width control in hot strip mill includes sizing of a continuous cast slab, decreasing the fish tail crop loss in the head and tail ends of rough bar, minimizing the width deviation or automatic width control (AWC). These have been studied in order to increase the material yield as well as to improve the strip width accuracy. The authors have developed an automatic width control system, which consists of a width-gauge feed-forward control and learning control to improve the width accuracy at the roughing mill delivery side by adjusting the roll opening of the hydraulic AWC edger. This paper covers the general description of the mathematical model of width deformation, the characteristics of the control system and the excellent capability of this system, confirmed by an actual edging operation in a hot strip mill.
  • 加藤 高明, 浦田 暎三, 中西 実, 山崎 一男
    1990 年 56 巻 526 号 p. 1626-1631
    発行日: 1990/06/25
    公開日: 2008/02/21
    ジャーナル フリー
    Seamless pipes have some terminal end bends which must be cured before shipment. This paper describes a real-time control system for a press straightening process. The straightening process must account for elastic springback, which is a strong function of the material properties of the pipe. On-line measurements of reactive force and deflection of the pipe during the early part of the bending process are performed to form an elastic-plastic model in a microcomputer. The final correct die position to yield the desired unloaded shape is predicted using the elastic-plastic model. Through a series of experiments on different materials and different sizes and shapes, the straightening process gave an accuracy of 0.18 mm/m, which is sufficiently smaller than product allowances.
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