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長屋 幸助
1988 年 54 巻 503 号 p.
1393-1400
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
This paper discusses transient stresses in a general shaped three dimensional curved rod with an arbitrary cross section subjected to general transient excitation. The paper gives and analytical method for finding normal and shear stresses in the rod by use of the transfer matrix, the Laplace transform, the Fourier expansion and the Fourier expansion collocation methods based on the there dimensional curved beam theory. As an application, this paper treats the coil spring of an arbitrary cross section, and proposes a rational coil spring having an oval cross section. It is clarified that the oval cross section coil with an appropriate aspect ration has various advantages as compared with the circular cross section spring.
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久保 雅裕, 大坪 康郎, 川島 教嗣, 丸茂 斉
1988 年 54 巻 503 号 p.
1401-1406
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A new method to measure the flying height of head sliders in magnetic disk devices was developed. The interference color fringe created in the clearance between the slider and the glass disk was characterized by using the color image processing technique. The relation between hue and the flying height was obtained within 0.0073μm accuracy. The presented method makes use of the phase difference among RGB signals, so it doesn't depend on the light intensity distribution in the TV field, which comes from the optical devices. In addition, the present method gives continuous flying height attitudes.
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佐藤 満弘, 片岡 更一
1988 年 54 巻 503 号 p.
1407-1410
発行日: 1988/07/25
公開日: 2008/02/21
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フリー
When the circular arc beam, of which the centerline is a circular arc, and the cross sections suddenly very stepwise, vibrates in the plane of the beam, the frequency equation is determined by using Hamilton's principle. This analysis was carried out by taking into account the effects of shearing deformation, rotary inertia, and moreover, deviation of the centroid from the neutral plane. Since the frequency equation became a transcendental equation, its solution was determined by the method of iterative calculation using a computer. However, it was assumed that the material quality of the beam used for the numerical calculation was the same in all steps, and that the cross sections were circular. Besides, the supporting condition at both ends was assumed to be fixed. Then, the relation of the dimensionless natural frequency with the diameter ratio and opening angle, and the natural mode of vibration were shown in figures.
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瀬口 靖幸, 田中 正夫, 山口 智久, 笹部 幸博, 辻 英男
1988 年 54 巻 503 号 p.
1411-1418
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
The geometrical configurations of statically determinate trusses having the same topology but different lengths of members are not the same. This suggests that the truss structure may work as a flexible arm by changing the length of each member actively, and a highly multiple degree of freedom may be obtained by regarding each member as one degree of freedom. The scope of this paper is to establish the fundamental idea and the formulae to describe the dynamic motion of the truss-type arm system. The incremental relationship for kinematic motion is described first, and then the equation of motions are established in the context of an extended matrix structural analysis based on the Lagrangean approach, since the kinematic degrees of freedom are identical to that of its structural deformation. Some numerical simulations are demonstrated with respect to the kinematic and elastic motion of the arm.
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田中 信雄, 菊島 義弘
1988 年 54 巻 503 号 p.
1419-1426
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
In order to suppress an impact vibration, this paper presents an active control method using a servodamper with a preview action. It is also the purpose of this paper to establish the design procedure of the servodamper system, as well as to verify the capability of the proposed method. First, from the viewpoint of the preview control method, this paper describes system equations of the servodamper system. Then, by using a parameter optimization technique, the necessary conditions for the optimal servodamper system are derived. Moreover, based upon the design procedure, a control on the control effect of the servodamper system are investigated. Furthermore, aiming at a simple control system of the servodamper, a relation between an order of the control compensator and the control effect is clarified. Finally, the robustness of the servodamper system is discussed and a perspective to realize the servodamper system with a preview action is obtained.
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岡田 養二, 永井 文秀, 松田 健一
1988 年 54 巻 503 号 p.
1427-1432
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A semi-actively controlled vibration damper is introduced which is intended to add the damping property to the structure. The electrodynamic actuator is used to produce the damping force and the actuator mass is supported by an additional spring to cause the dynamic absorber. The back electromotive effect is utilized to produce the damping force which is controlled by the measured vibrating signal. System is simulated on a a computer to evaluate the damping effect. The frequency response is calculated by changing the parameter, and the tuning condition is obtained to cause a good damping effect. A simple experimental apparatus is made to confirm the effect of this semi-active dynamic damper.
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岩田 佳雄, 佐藤 秀紀, 高森 良裕, 田村 章義
1988 年 54 巻 503 号 p.
1433-1438
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
An imitation crack which has the same deflection characteristics of cracked rotors and which enables a large crack depth has been thought up, and a vibrational experiment on rotor with an imitation crack, supported horizontally, has been done. Resonance curves and FFT analyses of vibrational waves are measured in the experiment and are shown. As a result, it is found that additional resonances at 1/2, 1/3, 1/4 and 1/5 of the critical speed are caused by the imitation crack. Especially, it has been observed that an unstable vibration occurs at 2/3 of the critical speed in the large crack case. The relation between the stiffness and the rotating angle of the cracked rotors is discussed for the vibrational analysis.
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曽根 彰, 鈴木 浩平
1988 年 54 巻 503 号 p.
1439-1444
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A practical calculation method is presented from the viewpoint of the aseismic design convenience for liquid storage tanks and various piping systems established in industrial facilities such as petrochemical plant complexes. Utilizing the results obtained in the previous studies, correlation effects appearing among different loadings and response reduction effects due to structural nonlinearities such as gaps and friction between piping and a supporting structure can be represented by a numerical diagram prepared for various system parameters. According to the calculation based on this diagram, sophisticated seismic response calculation procedures can be remarkably simplified. Several examples are demonstrated.
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大矢 誠, 穂苅 久, 田村 久司
1988 年 54 巻 503 号 p.
1445-1451
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A calibration method of the three-coordinate measuring machine (3CMM) is presented. Two types of three-dimensional standard gage made by the authors were used for the calibration test. In this method, the error vector was directly observed and determined by comparing the measured value with the true value of the gage. The discrete distribution of the error vector was thus obtained. This method is convenient for machine shop applications. Based on the proposed method, the calibration test was performed on the 3CMM. To verify the accuracy of the calibrated 3CMM, distance measurements were performed using the gage blocks, and the measured values were corrected. As a results, it was clarified that the error correction using the result of the calibration test improves the accuracy of the 3CMM.
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吉村 靖夫, 天田 勝正, 赤坂 隆
1988 年 54 巻 503 号 p.
1452-1457
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
One piece parallel spring movement has an unique point, a load applied on which makes its carrier move rectilinearly without rotational displacement, or pitch. It is significant to study the effect of errors in dimension of leaf springs, that is, length and thickness, on pitch error which dominates the capability of a movement designed to move with translational motion. Theoretical analysis followed by Finite Element Method (FEM) help the authors make sure the most important thing in this paper as following; As long as both two leaf springs are symmetric in their shape, with respect to a given line, no pitch error is observed, resulting in the carrier being moved with rectilinear motion. The line mentioned above is the one which passes through the midpoints of two springs in the longitudinal direction.
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尾上 佳史, 萩原 憲明
1988 年 54 巻 503 号 p.
1458-1462
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
This report is an experimental analysis of jumping phenomena of timing belts widely using in office automation machines. It is found that belt and shaft stiffness, tension, temperature and so on exact influences on belt jumping, from the experiment. The facts suggest that it is most essential for prevention of jumping to make a belt more easily and more uniformly engage with pulleys by choosing a belt type and changing shaft stiffness and belt tension.
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小尾 誠, 松本 達也, 小林 隆志
1988 年 54 巻 503 号 p.
1463-1468
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
The present paper discusses on a method for measuring flatness, to control not only the size accuracy but the shape accuracy of works on machine tools. The method for measuring flatness demonstrated in the present paper is based on the straightness measurement proposed recently by Tozawa and et al. Two or three sensors are attached to the measuring apparatus and are rotated through the angle which corresponds to the angle between the sensors. Therefore, the relative displacements between the sensors are measured continuously. A summary of the results is shown below. 1) The method of flatness measurement using the displacement at 2 or 3 points continuously is shown; 2) The measurement for flatness requires the data processing of calibrations of the sensor's position, calculations of the displacements at the measuring point and coordinate transformation; 3) The calculations for flatness are optimized by the simplex method; 4) The principles of flatness measurement proved to be efficient by computer simulations.
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宮下 晃一, 一宮 亮一
1988 年 54 巻 503 号 p.
1469-1474
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A new accurate measurement of displacement by means of sound frequency variation in a resonant pipe has been investigated. This paper deals with the theoretical analysis of the sound frequency variation which generates in the pipe. The acoustic input impedance and the acoustic radiation impedance between the pipe and a substance vary with the displacement of the substance which is placed at the other end of the pipe. These two impedances were introduced under a new idea and the sound frequency variation was calculated with the impedances. The results of the sample calculations and the experiments coincide to a significant extent.
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土居 俊一, 安田 栄一, 林 靖享
1988 年 54 巻 503 号 p.
1475-1479
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
Vibration-cotrolling equipment is developed by aiming at the optimum vibration adjustments for structural supports with slight energy dissipation. This equipment is located between the vibrational members and composed of the newly designed damping-force converter by valve-opening adjustments. In this system a linear quadratic optimum regulator is used not for the so-called active powered force control but for the determination of the desired force function generated by a semi-active control device. Some experimental results by using the model apparatus of 2 degrees of freedom are given following these systems.
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楊 春信, 下郷 太郎
1988 年 54 巻 503 号 p.
1480-1488
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
In the design of an off-shore tower-like structure, which consists of two pipe sections assembled with universal joints and attached to a buried sinker block on the sea bed, enough buoyancy can be provided to keep the structure vertical. It is desirable to reduce both the structural oscillations due to random wave excitation forces and the reaction forces acting on the sinker block. Assuming that the motion of the structure is two-dimensional in the vertical plane, these design requirements can be effectively satisfied if appropriate restoring and damping coefficients are provided at the joints. In this study, we employed the statistical equivalent linearization technique to linearize a nonlinear fluid drag force, and applied a sub-optimal control theory with control structural constraints to obtain the optima stiffness and damping coefficients required at the joints after a trade-off between the rms values of the top displacement of structure and the rms values of control moments at the joints.
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成田 忠雄, 疋田 弘光
1988 年 54 巻 503 号 p.
1489-1493
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A method to design a robust servomechanism by continuously variable structure control is proposed. The state and control signal of this servomechanism do not chatter since a continuous control scheme is used. The input-output relation of this servomechanism is determined by prescribing a hyperplane in s state space of which the neighborhood is asymptotically attractive every where. The control scheme guarantees that state trajectories starting outside the neighborhood of the hyperplane tend towards it and state trajectories starting inside it stay in it. Therefore, this servomechanism is less insensitive with respect to parameter variations, disturbances and nonlinearity. The output error which is caused by the deviation of the trajectory from the hyperplane is further derived as a function of the deviation. The results are extended to obtain a robust servomechanism of type l. An example is given in order to illustrate the efficiency of the proposed design method.
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武藤 高義, 豊岡 司, 末松 良一
1988 年 54 巻 503 号 p.
1494-1499
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
The object of this study is to develop a simulation method which aims at calculating the time response of hydraulic control systems. The main feature of this method is that it is applicable to hydraulic systems with fluid line elements. In the previous papers, a fundamental investigation for simulating various kinds of fluid line systems was carried out. In the present paper, therefore, a hydraulic system in which the effect of fluid line dynamics can not be neglected is tackled from a practical point of view. An electro hydraulic servosystem is chosen as representative for such an application. In the simulation, response curves of output variables are calculated, together with pressure responses at arbitrary positions of the fluid line. The results are compared with the measured responses to confirm the validity of the method developed.
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加藤 隆, 中里 裕一, 中川 光弘, 川元 修三
1988 年 54 巻 503 号 p.
1500-1503
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
When the wheel-type locomotive robots move on a set of stairs, it is difficult for them to maintain a sense of balance and stable motion. In this paper, we deal with a new type of locomotive robot which is able to move in a plane and to go up and down a set of stairs. The robot, with its leg attached to a wheel, is formed by a series of mechanisms which allow it to ascend and descend in a vertical line. This method we denote as of the leg-vehicle type. A step is measured in terms of height and depth by using ultrasonic sensors. Our results indicate that stable locomotion of a leg-vehicle type robot can be attained.
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小笠原 昌和, 原 文雄
1988 年 54 巻 503 号 p.
1504-1509
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
The motion of a robot manipulator submerged in water is affected by added mass, fluid drag force and flow-induced vibration. This paper, thus, deals with a technique for reducing these fluid influences on the manipulator's motion by ejecting air bubbles from the surface of the manipulator. Using a two-degree-of freedom and two-joint manipulator, experiments were carried out and the following major results were obtained: (1) the starting torque required for the manipulator's motion in the water is reduced to the magnitude for that in air by a certain bubble ejection pattern and ejection air pressure; (2) there existed a particular bubble ejection pattern and ejection pressure that were effective in reducing the drag force by 40%; (3) air bubble ejection from the surface increased the lift force acting on a link moving in the water; and (4) total fluid force composed by the lift and drag was, however, reduced by 40%, compared with that in the water, for a particular condition of air bubble ejection.
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金子 真, 横井 一仁, 谷江 和雄
1988 年 54 巻 503 号 p.
1510-1514
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
Force (moment) vector and displacement (displacement angle) vector at the end-effector of robot manipulator are connected through a compliance matrix which can be directly specified by each joint compliance. On the basis of this consideration. Direct Compliance Control (DCC) is proposed and developed for a serial link arm. A framework of the analysis is described for a generalized serial link arm model having n(n+1)/2 compliance components (n: rank of the compliance matrix), and several features of DCC are made clear in comparison with the conventional compliance control scheme. A serial link arm in a horizontal plane is selected as an example of precise model analysis, and the decoupling condition of the compliance matrix is also presented. In order to check the validity of the analysis and the decoupling condition, computer simulations and some experiments are performed for several arm attitudes.
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谷江 和雄, 横井 一仁, 金子 真
1988 年 54 巻 503 号 p.
1515-1519
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A new method of torque control using a DC motor with reduction gears has been investigated. A variety of robot applications requires a robot to have both compliance and rigidity in motion control. There is a competitive requirement to be satisfied in the design of actuation systems suitable for the robot motion. In order to achieve compliant motion, a gear reduction DC servomotor with torque sensory feedback is generally used in robot arm joints. Introducing torque sensory feedback provides a benefit for stable torque generation at the expense of the rigidity of the drive system, and in turn causes a low response of joint position servomechanisms. To improve the response, the position based DC motor control method in which torque output can be produced proportional to the input signal without stiffness reduction is proposed. Feasibility experiments which show that the proposed method is effective are described.
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上野 拓, 矢野 満, 井上 繁, 五家 政人
1988 年 54 巻 503 号 p.
1520-1524
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
This paper discusses the hobbing of gears made of austempered spheroidal graphite cast iron, which has become the object of attention recently as a new material for gears. This iron has many advantages such as a high strength equivalent to steels, and is an economical material. But as things are hobbed before heat treatment, the cutting of teeth of a hardened gear blank is considered very difficult. The cost will be lower because the gear can be used without a finishing operation on the tooth surface removing the distortion from heat treatment. In cutting tests, at first a basic test was conducted by using a fly-tool having the same form as that of one blade of a hob. As a result, it was made clear that hobbing can be performed giving long tool life by using a tool with a large relief angle (20°).
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丘 華, 梅崎 洋二, 有浦 泰常
1988 年 54 巻 503 号 p.
1525-1529
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
Recent studies showed that the tooth profile errors of hobbed gears were mainly caused by the geometrical error and eccentricity error and eccentricity of the hob under good cutting conditions. Because manufacturing a highly accurate hob is very difficult and maybe a highly accurate gear is not obtained even though a highly accurate hob is used, it is very important to investigate how to improve the actual meshing accuracy of the hob in the cutting process. In general, the meshing error of the edges caused by the hob eccentricity is nearly sinusoidal and also the geometrical errors often contain sinusoidal components. On the basis of these facts, this report proposes a method which makes both of the sinusoidal error components cancel each other out in order to obtain an accurately hobbed gear. The test results clearly show its usefulness to improve the tooth profile errors of the gears.
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田中 成忠, 江副 覚, 穂屋下 茂
1988 年 54 巻 503 号 p.
1530-1534
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
Static load sharing between the gear pairs with different tip relieves at the position of simultaneous contact has been studied by using mirror-like tooth surface gears with high accuracy (R
max=0.1μm, JIS M 00 class). Utilizing the gear testing machine, load on the individual tooth at the contact point along the line of action has been measured statically by the strain gauge cemented on the tooth root-It was observed from the results that abrupt changes of load at the initial and final points of contact were reduced by the tooth profile modification. Even though running-in are expected to the low hardness gears, it is necessary to modify the tooth profile in order to improve the oil film formation, and to increase the surface durability of gears.
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岸 佐年, 両角 宗晴, 吉田 嘉太郎
1988 年 54 巻 503 号 p.
1535-1540
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A precise analysis has been made on the profile of the relief grinding wheel of the type 3 worm hob. Firstly, the type 3 worm thread surface, which is normal to the basic thread surface of the hob, is chosen as the helical cutting face of the type 3 worm hob. Secondly, the axis of the relief grinding wheel for this worm hob is tilted in a three-dimensional direction to the axis of the worm hob. Thirdly, the calculation method for the profile of the relief grinding wheel is obtained. Then, the experimental manufacture of a relief grinding wheel is made by applying this calculation method to a numerical example of the type 3 worm hob. The theories in this analysis are verified by practical relief grinding of the type 3 worm hob with this relief grinding wheel and by the measuring of the profile of the cutting edge of the worm hob. The necessity and the effectiveness of this calculation method are confirmed.
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藤尾 博重, 真下 伸也
1988 年 54 巻 503 号 p.
1541-1546
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
In this paper, the reproducibility of single pitch errors computed from some transmitting error records through a single flank meshing test is confirmed by changing a pair of tooth mashings under a constant center distance between a master gear and a test gear. Also a method which gives the runout from single pitch errors is shown, and the runout from this method is compared with the result of a conventional measurement. For a ground gear, the runouts from the two measurement methods have a good coincidence because of less lead error, but for the hobbed test gear with a large lead error, they differ to a certain extent. However, even in this case the runout computed from transmitting error records has a good tendency qualitatively, and this fact shows a necessity to develop a master gear, with which the runout can be measure with high precision.
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山羽 和夫, 小石川 勝男
1988 年 54 巻 503 号 p.
1547-1551
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
This paper deals with a break-detecting method of a thin drill used in NC machine tools and machining centers. It is very difficult to detect a break of the thin drill less than 2 mm in diameter by the AE sensor with a high degree of accuracy. A transistor chopper circuit which has a very effective soothing reactor to control a dc motor at a constant torque is developed. In this chopper circuit, high speed transistors are employed and the current of the dc motor is always saturated perfectly. Thus, the breaking torqe can easily be detected even though the value is very small. An experiment for detecting the breaking torque is performed on the thin drills which have the diameters of 1, 1.5 and 2 mm, respectively. On the basis of the experimental results, it has been proven that the break-detecting method can be applicable to the thinnest drill of 1 mm in diameter.
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石川 晴雄, 小島 之夫
1988 年 54 巻 503 号 p.
1552-1558
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A new method is proposed to estimate the distribution of tooth root stress of a gear pair under partial and nonuniform contact by a three-dimensional finite element method. In the method, the usual finite element program can be used with no special changes. To check the accuracy of the present method, a contact problem of two circular disks is analyzed. Numerical results are obtained with good accuracy, comparing with the results by Hertz theory. A pair of spur gears with lead error which gives partial contact is analyzed by the present method, and the distributions of tooth root stress and tooth deflection are obtained. The results are compared with those given by the draft proposal of ISO and by the standard of AGMA.
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晴山 蒼一, 浜田 秀樹, 石丸 源一郎
1988 年 54 巻 503 号 p.
1559-1563
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
Many papers have been published on the self loosening of bolted joints, making estimations of the lock effect from laboratory tests using a loosening test machine. However this kind of test method is only effective for the comparison of locking devices. In this paper we propose a method for estimating the absolute lock effect during actual machine operation. The authors found that there is a linear relation between axial tension and the time after the tightening on a log-log scale, in both static and dynamic loosening. Based on this relation, the authors proposed a method for estimating the decrease of axial tension accurately after long hours of tightening by measuring the initial behavior.
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新田 勇, 下田 茂, 石橋 達弥, 加藤 康司
1988 年 54 巻 503 号 p.
1564-1571
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
In the previous paper, we theoretically analyzed the distributions of the contact pressures between ceramic and metal whose cylindricities were not perfect. In this paper, the distributions of the contact pressures in the circumferential direction were theoretically analyzed when the roundnesses were not perfect. The distributions of the contact pressures were changed as the degree of out-of-roundness was changed. Shear stress did not exist on the surface to be jointed. The mean contact pressures decreased with increased surface roughness. And the concentrations of the contact pressures caused by the out-of roundness were relaxed by the roughened surfaces to be joined. The effects of both out-of roundness and surface roughness on the fractures of ceramic rings were also discussed. And it was shown that the roughened surfaces to be joined prevented the ceramic rings from fracturing.
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筒井 敏, 青山 藤詞郎, 稲崎 一郎, 清水 哲
1988 年 54 巻 503 号 p.
1572-1576
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
Oil-air lubrication is one of the effective lubrication methods for the high-speed spindle of machine tools. However, the oil supply rate to the bearing fluctuates remarkably due to the intermittent oil supply from the oil-air mixing valves. In this study, a new oil-air mixing equipment is developed by applying the piezoelectric nozzle which has been used for the printing head of ink-jet printers. By using the piezoelectric nozzle instead of the conventional mixing valve, the fluctuation of the oil supply is successfully suppressed. And it becomes possible to attach the oil-air mixing equipment close to the bearing. The oil supply rate can be, therefore, quickly changed in response to the change of running condition of the bearing.
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田中 裕久
1988 年 54 巻 503 号 p.
1577-1583
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
A traction drive CVT of toroidal rolling elements changes its speed ratio by the control of the attitude angle of the power roller of which control force is induced from a little side slip. In this paper, geometric contact points and the side slip velocity are found by vector analysis, and both the traction force and the side slip force which swings the power roller are calculated by the thermal EHL theory using the elastoplasic traction fluid model. The calculated results are compared to the experiments of the prototype of the torque transmission capacity of 140 Nm. It is concluded the necessary and sufficient percentage of the side slip velocity should be designed to be no more than 2 %.
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林 嵩, 青山 藤詞郎, 稲崎 一郎
1988 年 54 巻 503 号 p.
1584-1589
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
The whirl instability of groove compensated journal air bearing is analyzed. The finite element method is used to obtain the numerical solution of the Reynolds equation and the computer simulation method is used to obtain the locus of the shaft center after a step displacement disturbance. From the shaft loci, the effects of various design parameters on the stability of the bearings are discussed.
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会田 誠治, 稲崎 一郎, 小林 茂邦
1988 年 54 巻 503 号 p.
1590-1594
発行日: 1988/07/25
公開日: 2008/02/21
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フリー
Creep-feed grinding is an effective machining process to increase the productivity of difficult-to-machine materials. However, this method has some problems, i.e., the increase in the grinding force and the occurrence of grinding burn caused by the excessive attrition of grain cutting edges. In this study, Creep-feed grinding with intermittent dressing using a CBN-wheel is proposed in order to solve these problems. Through the experiments it is confirmed that this method is effective to suppress the increase of grinding force and is superior to Creep-feed grinding with continuous dressing because of a smaller consumption of the grinding wheel and the dresser.
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井上 誠, 石井 靖久, 佐藤 憲一
1988 年 54 巻 503 号 p.
1595-1598
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
The porous type wheel made for creep feed grinding with difficult-to-grind materials is excellent for the prevention of workpiece burning, but its wear is usually considerable. So we must exactly obtain the characteristics of wheel wear in the case of precision profile creep feed grinding operation. In this study, V profiled wheel wear is examined experimentally with SUS304 and SKD11(Hrc60) materials. From the results, characteristics of the edge wear and the linear relationship between wear and the inclined angle of the wheel surface are obtained. Further, a method is proposed by which any profiled wheel wear is able to be estimated using this relationship from a simple creep feed grinding test. And the usefulness of the method is examined experimentally.
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梅原 徳次, 加藤 康司
1988 年 54 巻 503 号 p.
1599-1604
発行日: 1988/07/25
公開日: 2008/02/21
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フリー
A new grinding method using magnetic fluid containing abrasive grains was studied. This method was named magnetic fluid grinding. The magnetic buoyant force of abrasive grains produced by a magnetic field was generally too small to produce an effective grinding load. In order to obtain a larger grinding load, a new grinding tool, which was called the floating pad, was introduced. The floating pad in the magnetic fluid was very effective in increasing the removal rate in grinding. The floating pad was also effective for producing smooth surface and better sphericity of ball specimen. Therefore, it was concluded that the floating pad was and essential tool for practical magnetic fluid grinding.
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村田 真, 横内 康人, 小野寺 和宏, 鈴木 秀雄
1988 年 54 巻 503 号 p.
1605-1609
発行日: 1988/07/25
公開日: 2008/02/21
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フリー
The authors have developed new equipment for tube bulging which initially puts a deflated rubber membrane into a work tube and drives the internal pressure through a membrane after an initial setting-up. Using this new equipment, the effects of the tube end condition and tube length on the deformed shape and the strain distribution are examined experimentally. Three cases of the tube end conditions of (A) axially fixed, (B) axially free and (C) axially compressed by force are parametrically investigated. The Results are concluded as follows: (1) Comparing at the same bulge height, the internal pressure is lower with the longer tube and also lower with the end condition changing from case A to C, (2) When the tube is short and/or the axial compressive force is small, the deformed shape uppears as a barrel, and when the tube is long and/or the axial force and is large, it has a cylindrical region uniformly expended at its center, and (3) The axial compressive force tends to prevent thickness reduction of the tube.
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米山 猛, 畑村 洋太郎
1988 年 54 巻 503 号 p.
1610-1613
発行日: 1988/07/25
公開日: 2008/02/21
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フリー
Pressure, frictional stress in the rolling direction and that in the width direction have been measured in the cold rolling of aluminum strip and billet by a new stress sensor developed by the authors. Characteristics of the frictional stress distribution in cold rolling have been elucidated. Frictional stress in the rolling direction is almost constant from the entrance to the neutral point in the contacting arc, both in strip and billet rolling. On the other hand, frictional stress in the width direction increases from the centerline to the edge part and its peak lies in the central part of the contacting arc in strip rolling. However, in billet rolling, it has two peaks in the rolling direction and its value does not vary from the centerline to the edge part. This may be related with the metal flow to the width direction in billet rolling.
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岩田 一明, 杉村 延広, 彭 羅生
1988 年 54 巻 503 号 p.
1614-1619
発行日: 1988/07/25
公開日: 2008/02/21
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フリー
A mathematical analysis of product surfaces is carried out, aimed at developing a logical design methodology of machine structures. The relationship between the product surfaces and the shape generation process is analyzed on the basis of the mathematical models. Formulae representing this relationship are established through the analysis. An algorithmic procedure is proposed to determine suitable kinematic functions of the machines from the geometric information about the product surfaces.
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吉村 允孝, 吉川 尚宏, 人見 勝人
1988 年 54 巻 503 号 p.
1620-1627
発行日: 1988/07/25
公開日: 2008/02/21
ジャーナル
フリー
Industrial robots are being used more and more in complicated working environments which include obstacles. Industrial robots most suitable for a given working environment should be designed such that they avoid obstacles while moving in the working space. In this paper, a design optimization method is proposed for two-degree-of-freedom rotary angular jointed robots used in a working environment including obstacles. In this optimization, the lengths of the links, the cross-sectional shapes of the links, and the directional orientation of the robot installation are determined. First, the algorithmic procedures of the optimization method are presented. Then, analytical procedures for obtaining the feasible set of link lengths are described. Finally, the effectiveness of the method is demonstrated for designing a robot used in a given working environment.
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