Actual vibration spectra of the experimental 15m wind turbine of the Mechanical Engineering Laboratory were obtained to investigate the vibration characteristics of general teetered-rotor wind turbine systems in operation. Natural frequency tests were also conducted to search for the causes of steady vibration, where the natural vibration was excited with the disk brake located at the high-speed shaft. As a result, the tower bending resonance with 1P and 2P and transmission torsion resonance with 2P have been observed. It has also been found that the gravitational force is predominant for the blade chordwise bending and that various nP components due to the wind appear on the blade flapwise bending.

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This paper presents a theoretical analysis of longitudinal vibrations of a long pipe string with a buffer attached to its free bottom end. Natural frequencies and modes are evaluated. Furthermore, supposing the heaving motion of the ship to be sinusoidal, the steady-state responses of the pipe string are determined. It is found that the natural frequencies decrease with the buffer mass, and the steady-state response can be affected considerably by the buffer aspect-ratio as well as its mass. Because the oscillation amplitude at the bottom end of the pipe string can be amplified to several times that at the top end, this problem may be important in the design and operation of such mining systems.

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A long pipe string hung from the ship in a mining system in the deep ocean may be parametrically excited when the ship undergoes a heaving motion. The vibration of the pipe string does not grow exponentially as in a linear case, but is limited by the nonlinear drag force of the sea water. In this paper, a theoretical analysis is presented to study this limit cycle response of a two-stepped pipe string with a buffer attached to its bottom end. The effect of the longitudinal oscillation of the pipe string is included. Furthermore, the equation of motion is formulated by considering the effect of the constant relative velocity between the sea current and the ship. It is found that the system is excited either only parametrically or both parametrically and directly, depending on whether the relative velocity is equal to zero or not. The steady-state oscillations are determined by the method of harmonic balance, and the stability of the solutions obtained is also investigated.

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Free vibration modes of the axisymmetric shell with internal liquid are calculated considering the effect of fluid-structure interaction by using a conical shell finite element and a ring fluid element. The calculated free vibration modes are used to expand the free vibration modes of the axisymmetric shell with lumped weights and internal liquid. A type of Mathieu equation including the effects of the translational motion of the attached weight in the radial direction or the effects of the beam-type motion of the shell without lumped weight is derived. The harmonic balance method is used to obtain the parametric resonance regions. The principal resonance of a circular cylindrical shell with an attached weight and combination resonance of liquid storage circular cylindrical shells without attached weights are analyzed. Analytical results show good agreement with experimental results.

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This paper considers the active vibration control when the system is subjected to unknown deterministic disturbances which are generated by a linear dynamical system. An adaptive pole placement controller incorporating the internal model principle is designed. This controller can achieved both suppression of vibration and desired pole placement of the closed-loop system. Experimental results show that the amplitude of the vibration is reduced to approximately 10% of that on the uncontrolled state and that this scheme is robust for change of the disturbance frequency.

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A new measuring method of displacement by means of variations of sound frequency and length of air column in a closed resonant pipe has been investigated. In this paper, a speaker is used as a sound generating source in stead of air jet for the feedback excitation mechanism on the edge instrument. This paper deals with a new kind of displacement sensor using a electric feedback circuit. A sweep signal is radiated from the speaker through the small hole at one end of the closed resonant pipe toward inside of the air column. The sound pressure takes the largest value at the resonant frequency. The displacement of the plunger which is inserted from other end of the pipe, corresponds to the length of the air column. So, the displacement of the plunger makes good correspondence to the resonant frequency of the air column. The phase locked loop devise is adopted for stability of the resonation and frequency.

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The theory of linear suboptimal output feedback control with a frequency-shaped cost functional is applied to the vibration control of a vehicle model subjected to the input of the roughness of road surface. The feedback control gain is obtained with respect to a quadratic cost functional whose weighting matrices are functions of frequency. In the control using a frequency-shaped cost functional, the vibration frequency components can be reduced over specific bands of frequencies. Janeway and ISO human response curves with respect to acceleration are used to examine the vibration characteristics of a controlled vehicle model. The theory of the suboptimal control problem subjected to control structure constraints is applied to the synthesis of the output feedback control system. The theoretical and simulated results of the suboptimal output feedback control with a frequency-shaped cost functional are compared with those of the optimal control without a frequency-shaped cost functional and with state estimation using a Kalman filter.

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This paper deals with the flexural wave control of a flexible beam. It is the purpose of this paper to verify experimentally the existence of the active sink and to discuss the fundamental characteristics of the active sink system. First, for the purpose of observing the wave flow traveling along the beam, a visualization system is developed. Next, based upon the system, the experiment is carried out to verify the existence of the active sink. Then, from an analytical point of view, this paper further investigates the characteristics of the active sink system, showing that an active source also exists. It is also found that there are two patterns of the suppressed wave, that is, the progressive wave type and the standing wave type. Finally, by introducing both the phase distribution and the gain of the complex reflection coefficient over the beam, the generation mechanism of these patterns is clarified.

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In this paper the boundary element method for steady-state elastodynamics is applied to defect shape identification of structural components. It is assumed that the structural component under consideration has an internal defect and the strain responses measured on the boundary are available as additional information. This inverse problem is reduced to a typical optimum problem, in which the objective function is the square sum of residuals between the strains given as reference data and those computed for an assumed defect by the boundary element method. Numerical experiment is carried out for several example problems in two dimensions to demonstrate the usefulness of the proposed method.

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Repulsive magnetic levitation systems for vehicle suspensions are statically stable but dynamically of zero-or low-damping characteristics. Especially it is reported that electrodynamic suspensions have negative damping in some operating condition. In this paper, an active suspension is applied to the secondary suspension of the zero-damping magnetic levitation system in order to improve the dynamic stability of both the car body and the truck. The active suspension with a pneumatic actuator is designed by optimal regulator theory. The kinetic energy and the potential energy of both the car body and the truck are evaluated in an evaluation criterion. The two degress of freedom suspension model of this maglev system is analyzed theoretically and compared with the experimental results. The theoretical analysis and experimental results show that the dynamic stability is much improved by the active secondary suspension.

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In this paper the active control technology is applied to automovile vehicle dynamics. First, the transient response of the conventional 2-wheel-steering car is studied theoretically using a mathematical model. Results shows that the 2-wheel-steering system is non-minimum phase shift system and makes reverse reaction phenomena. Next, we propose a 4-wheel-steering system in which rear wheels are controlled as a function of rear steering. This system makes zero the horizontal angle of center of gravity and improve stability and control of cars.

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An injury arises from the transfer of potential or kinetic energy caused by the collision of a human with a hazardous object. Safety problems come from uncertainty involved in work space. As safety goes with information indicating safety of the work space, sampling and transmission of information on safety is indispensable as a means of proving safety. This paper presents 'principles of safety', describing (1) creation of safety, (2) continuity of safety, and (3) publication of safety. In order to achieve a safety (system) on the basis of the principles, this paper also explains that safety reporting means have characteristics of asymmetricalerror output signal generation and that the safety information to be reported must depend on the structure of the equipment involved. The asymmetricalerror rate is defined as a means of safety evaluation, and safety reporting means with asymmetricalerror characteristics are modeled as structures of a electric fuse and safety confirmation behavior.

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This paper is concerned with a discrete optimal design for beam. The optimal shape of the beam subject to a moving load is discretely obtained by using the Branch and Bound method, in which the thickness of the beams is regarded as a discrete design variable in the proposed design problem. The objective function is the root mean square (rms) value of the displacement of the moving load, and the constraint is the conservation of total mass for the beam. The gradients of the objective function are used in the branch stage in order to reduce the computational effort of the proposed method. The numerical examples of discrete optimal design are applied to beams with various conditions to show the effectiveness of the proposed method.

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A simple model of a pipe conveying fluid is studied in the context of a shape determination problem. The dynamics of such a pipe is a typical example of a non-conservative system. The equilibrium equations with boundary and initial conditions are transformed into the adjoint variational principle by using Lagrangian multiplier method. The stability is discussed in the critical velocity of flow, and then, the shape determination is formulated in order to maximize it. The gradient projection method is used to search the optimal solution. It is demonstrated through examples under several boundary conditions including cantilever that the proposed procedure is effective, and the obtained optimal shape is not necessarily robust with respect to a small fluctuation of the shape. A procedure is also proposed to improve the robustness of the optimal shape which is studied in the cantilever pipe.

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The machine of the man-machine system must be fail-safe to assure the safety of the human and a fail-safe interlock must be provided to allow the machine to perform the intended operation only when the human absent in the work area of the machine. But, as the matter of fact, a human operation such as trouble-shooting or maintenance is conducted under stop-hold condition of the machine. This paper addresses, such a system that a human operation can safely work with an industrial robot stop-holding in the common work area. The paper first shows a principle of safe work in a man-machine (robot) system. Described next is a prototype safety device (safety hold device) that actuates when the human works in close proximity to the movable part of robot in the stop-hold condition. Described last is fail-safe construction of the device. On the basis of the fail-safe logic, the safety device is so constructed that an erroneous operation signal produced by the safety device cannot permit the stop-hold operation and any malfunction of the device make a shut-off of the power source.

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Holonic Manipulator has electronic devices such as control computers and sensors among its local mechanical components. This manipulator design has three major advantages: reduction of wire harness between devices, high software productivity, and fault tolerability of the system. In this paper, first two actually developed Holonic Manipulators are represented. Then a simple structure model especially focused on the mass of the constituent components is developed so that the efficiency ratio of the payload mass to the manipulator's own mass can be analyzed. This ratio shows a slower increase consistently with the payload mass due to the DC servomotor mass/power characteristic and mechanical structure mass/stress characteristic. Fused structure design is employed mainly between heat sinks or support members of the computer and mechanical structure. Improvement of the efficiency ratio by fused design is estimated with the model using the mass fusion function.

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There are many papers in which various algorithms of the minimum time trajectory planning problem for manipulators are proposed, but many of them treat the case in which a manipulator moves in a full free task space. In this paper, an efficient algorithm for determining a minimum time trajectory is proposed under the condition that some spaces that the end effector of the manipulator cannot invade exist in the task space. The dynamical equation of the manipulator is expressed by a path parameter 's' which does not depend on time and is solved as a two-point boundary value problem. Input torques giving a desired trajectory are composed of two parts. One is for a minimization of the travelling time, and the other is for an avoidance of some spaces where the end effector is prohibited to enter. The avoidance is executed by introducing a potential function in the dynamical equation. Finally, the proposed method is applied to a simple manipulator with two links.

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A new approach to the static analysis of the link compliances is presented for appropriate compliance control of a flexible manipulator. Unlike a rigid manipulator, there exists the interaction between the servo flexibility and link flexibility in a flexible manipulator system. Therefore, it is important for smooth control to understand properties of the link compliances and make good conditions of the system compliances. For this purpose, the authors derived the generalized compliance matrix, compliance ellipsoid and compliance center of the link flexibility. It was found that there was an adequate attitude of a manipulator for excluding the influence of the link compliance and establishing tasks smoothly. The validity of this analytic method was investigated by experiments of the round peg-hole assembly. A two-link flexible SCARA manipulator system was constructed for this purpose. This manipulator was 1.5 m long. The results showed that the smooth and precise assembly was established by selecting adequate attitude and setting servo compliance conditions more flexible than the link compliances.

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Although there is a large demand for wire mobile robots, it is very difficult for the mobile robot to perform both obstacle avoidance and transferal to a branch wire. This paper describes methods of both obstacle avoidance and transferal to branch wires for the wire mobile robot with a multiunit structure. Basic analysis, synthesis and experimental results clarify both the kinematics and control method for the mobile robot with a multiunit structure which can perform both obstacle avoidance and transferal to a branch wire. Moreover, we demonstrate an ultrasonic sensing system for environment recognition, which is necessary for autonomous robot motion. Although the multiunit structure can realize an obstacle avoidance mechanism, its structure uses many actuators. Therefore, we proposed a compact wire mobile robot with a balancer to transfer the center of gravity.

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The safety control system, which is defined as machine operation controlled accordsng to safety confirmation information, is explained as an interlocking model that functions so that energy output from the machine is permitted only while the information (safety information) reports safety. The information transmission properties presented in this model are applied to all devices is the interlocking system, including the sensors for producing safety information and the devices for transmitting/outputting energy. A small energy-level signal signifying safety is normally produced in a pickup element in the sensor. Enormous power generated by amplifying the energy of the safety signal is supplied to the machine to conduct its powerful operation. This paper discusses the condition of the energy transmission process in which energy is produced in a safety sensor as a signal indicating safety and is amplified in the interlocking system up to the sufficient level for performance of machine duties. Firstly, in this paper, the characteristics of information to be provided with the means of information processing in the interlocking system are clarified. Secondly, a logical fail-safe model is proposed for clarifying the production condition of the safety information. Lastly, this fail-safe transmission of information energy can be applied to not only electrically but mechanically processed safety information.

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In the recent field of the fishery, the improvement of the efficiency, automation and labor deduction are needed. A counting task in this field is very important in many cases. In this paper, we present a system which enables a real-time measurement of the number and also the body length of the fry using a line image sensor. Here, we consider a situation that fry are transported from one pond to another pond through a pipe. In our system at one position of the pipe a transparent rectangular channel is mounted. The images of the fry, which run through this rectangular channel, are detected with a line image sensor. The image signals are digitized to binary ones and the contour of the fry are detected. After that, a real-time image analysis is executed with DSP (Digital Signal Processor). Overlapping of two fry images is also analysed. Whenever the fry pass the rectanglar channel, the DSP gives us the number and projection area surrounding length of fry images.

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A new technique has been developed for measuring the transient film thickness in a spin-coating process. Interference of a reflecting laser beam from film surface and film base is used in this technique. This laser beam is rotated synchronously with a spinning disk using a rotating prism which rotates at half the speed of the spinning disk. The rate of decrease in film thickness is obtained by measuring the frequency of change of the interference beam intensity. Using multiple laser beams, this technique allows simultaneous measurement at several arbitrary points. This technique has been applied to a photoresist spin-coating process to determine the dependence of the film thickness upon disk angular acceleration and photoresist viscosity. The rate of decrease in film thickness increases with the increase in angular acceleration and the decrease in viscosity. The change of the radius of the measuring position does not have much influence on the results.

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A mesh generation technique which generates a two-dimensional computational mechanics model is suggested for mechanical design work. The technique is based upon the extended quadtree representation method for a geometric model, and utilizes design model attributes, known as features, to generate a well-graded mesh. The design model is described by three kinds of data, geometric data, structural data, and product data. The product data are defined by the feature data, which are categorized into four types: environmental data. material data, functional data, and figure data. Each feature datum has a degree of importance to the design model. Also the feature describes the meaning of geometry, the intention of analysis, and so on. In the mesh generation procedure, the quadrant detects the degree of importance and the mesh density is controlled by handling the depth of the quadtree, in order to generate a well-graded mesh for either FEM, BEM, or FDM. The technique is also useful for an h-version of the remeshing process.

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The method for the dynamic analysis of a rotor-journal bearing system in which large dynamic loads act on the rotor is introduced, and the fundamental equations are solved by numerical calculation. The system is analyzed as a coupled problem of the momentum equations of a rigid rotor and the Reynolds equations of the oil film in all the journal bearings supporting the rotor. The method of analysis when a relative misalignment exists between the bearings is also presented. A rigid rotor supported by three bearings is analyzed for a rotary compressor. The rotor action, bearing load characteristics and the influence of misalignment are shown as the results.

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Using a two dimensional statical model of the cycloidal reducer, the load acting on each element was calculated. Then the effects of assembly and run-out errors of elements and clearance at the eccentric cam bearing on the load acting on that bearing were discussed, and the following conclusions reached. Even if there is no error in elements, the loads on two eccentric cam bearings are not equal to each other. Assembly and run-out errors of the cycloidal disk and of input and output shafts affect the variation of the load on the eccentric cam bearing, but they hardly affect the mean value of varying load. Each direction of the run-out error of the cycloidal disk at the initial state should be in the radial direction to the center of the reducer. Both the outer diameter of the eccentric cam and the inner diameter of the cycloidal disk hole should be machined with special care.

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It is well known that the life of TiN-coated hob becomes tremendously longer than that of non-coated hob. But even a TiN-coated hob, its rake surface must be resharpend when it was worn out. And then TiN-coating on rake surface is removed but only on flank surface. And TiN-coating on flank surface is still effective to decrease the flank wear. On the contrary, crater wear on rake surface of TiN-coated hob increases, same as that of non-coated hob. So, in high efficiency hobbing, the life of hob seriously depends on the crater wear. Here, the authors have clarified the shape of wear on TiN-coated hob to know its process and show some methods to increase the life of TiN-coated hob in case of high efficiency hobbing of the comparatively small module gears with TiN-coated and multi-start hobs that are often used for motorcycles and automobiles.

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The object of this paper is to clarify the effect of the temper of pure aluminum sheets on the surface flattening mechanism and friction behavior in the cup-ironing process. Ironing tests were carried out with cups drawn from three kinds of tempered pure a aluminum sheets. The results showed that on the die surface, the friction coefficient tends to increase with harder test cups. To understand this phenomenon, experiments with annealed cups were performed. Compared with the as-drawn cups, in the case of the annealed cups, the friction coefficient becomes smaller because the lubricant flowsmore easily into the contact interface and can be trapped there in.

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In order to analyze the vibration of a structure whose elements are connected with bolts, it is necessary to estimate the rigidity of bolted connections. Some studies on annular flange connections have been reported. In these studies, the bolt axial force and sealing performance are examined in detail, but the rigidity of annular flange connections is not discussed sufficiently. This paper deals with a calculation method to estimate the rigidity of bolted annular flange connections subjected to external loads in the axial direction. In the analysis, a model for estimating the axial rigidity of annular flange connections is proposed taking account of the dispersiveness of bolt disposition and the rigidity of the flange-shell junction. That is, the annular flange is replaced with a plate and the hub with a cylindrical shell. For verification, experiments are performed. The calculated results are in fairly good agreement with the experimental ones.

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Several gear reducers are proposed and employed selectably in controlled machine systems, such as robotics or industrial machines, according to the proposed function of those systems. Usually these gear reducers produce speed and torque variation caused by element error, alignment error, backlash, other nonlinear characters and meshing principles. This paper deals with the elimination of such vibration in a rather low frequency range, generated especially by element and alignment errors. To eliminate these low-frequency components of vibration which is locally generated inside the gear reducer, a local feedback loop with a sensor at the final stage of the reducer fed into the main controller, i. e., self-compensating function, is useful.

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In the previous reports, the simple analytical model of cutting mechanism in gear shaving was proposed, and a computer simulation program for gear shaving was developed on the basis of this model. Using this simulation program, the calculated tooth forms of the shaved gears showed a good qualitative agreement with the measured ones, but they were rugged tooth forms superimposed on the measured ones. In the present report, we analyze a cutting mechanism in gear shaving to propose a more precise model. As a result, it is found that there are three states of contact between the land of the cutter and tooth flank of the work-gear. Penetration tests are carried out to obtain the empirical equations which represent the relations between the depth of the penetration and the resistance to the penetration of a cutter land edge to a work-gear tooth flank. In these tests, tool rollers with and without serrations are applied to a steel block. Using the empirical equations obtained here, the calculated tooth forms of shaved gears show no rugged shape. It can be concluded that a more reliable computer simulation program has been developed.

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Spiral bevel gears have been used in various fields. And, there are two types in them, that is, the tapered tooth depth along tooth width and the uniform tooth depth along tooth width. But, the systematic study dealing with the dynamic behavior of them have hardly been established. At present time, the former is used widely for transmission gears of motor cars. Therefore, it is one of the most important subjects in the motor car industry to clarify the characteristics of these gears. Under present day situations, the Gleason-type (tapered tooth depth) spiral bevel gear was chosen as a subject of our studies. That is to say, the tooth root stresses and vibrating acceleration of the gear housing under various running conditions were examined, and the dynamic behavior of the Gleason-type spiral bevel gear was clarified.

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Twisting tests for cup type strain wave gearing (commonly known as harmonic drive gearing) were done to grasp torsional factors of the gearing. Also the radial flexural deformation of flexible spline (=F. S.) which was one of the structural elements of the gearing was measured with 3-dimensional coordinate measuring machine to consider the effects of flexural deformation on torsion. From the results obtained, the strain wave gearing had hardening spring characteristic, and for torsional factors of the gearing, not only cylindrical torsion of F. S. but also several torsional factors due to flexural deformation of open side of F. S. which meshed with circular spline were grasped experimentally. The sum of torsion caused by each of the grasped factors became about 95% of the whole torsion of the gearing.

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Induction-hardened stintered powder metal gears having a module of 5, a standard pressure angle of 20° and a contact ratio of 1.246 were fatigue-tested using a power circulating gear testing machine, in order to elucidate the fatigue strength and the relationship between tooth surface failure and dynamic performance during the fatigue process. The fatigue limit for the number of cycles to gear failure of 10⁸ was about 850 MPa by Hertzian stress. The failure mode of these gears was pitting. Pitting occurred at the dedendum flank of the gears in the initial stage of the fatigue process and developed to the addendum flank in the final stage of the fatigue process. The dynamic performance of the gears changed depending upon the tooth surface deterioration due to pitting. The pores existing on or beneath the tooth surface could play an important role in the initiation and propagation of pitting cracks.

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In this study, carburized gears of m=1.0-1.5 with various effective case depths are put to bending fatigue tests, and the fatigue strength is obtained. The test results verify that the effective case depth recommended in the AGMA standard is appropriate for the enhancement of bending strength. Arranging all results, SN curves are determined and illustrated. The fatigue strength of the gears is about 1100 MPa. The fatigue strength is compared with the strength of the gear teeth of m=5, and the effect of the tooth size on the fatigue strength is estimated quantitatively. The estimated size factors of the carbonized gears are 1.0-1.3.

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This paper presents a study on the residual stresses of case-hardened internal spur gears with various rim thicknesses and standard pressure angles. A heat conduction analysis of the temperature and an elastic-plastic analysis of the stress in a cooling process for the case-hardened internal spur gear are carried out by finite element method (FEM). The effects of the case depth, the rim thickness and the standard pressure angle on the residual stress are examined. The optimum case depth for the residual stress is also clarified.

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In this paper, we propose a heuristic tool allocation method for FMS's based on group technology. According to this method, a structured tool-part relation matrix is at first to be obtained by applying quantification theory III. Then the heuristics utilizing the properties of a structured relation matrix is applied to form part families and tool sets, considering the constraints on tool magazine capacity and available running time. By applying this heuristic method, independent machining cells can be formed for each part families, the part movements between the machines can be decreased, tool setup time can be reduced, and also good workload balance between the machines can be achieved. Consequently, the machine efficiency and the productivity of the system can be improved. This heuristic method is also shown to be valid and efficient by an example.

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This paper deals with the regenerative chatter vibration in a straight tool with an asymmetric cutting edge. The vibratory energy of the cutting tool is consumed by the interference effect between the tool flank and workpiece surface, judging from the vibratory loop configuration of the cutting edge and the effective relief angle variation during vibration. Regenerative chatter vibration of straight tools with an asymmetric cutting edge is excited by the regenerative effect of chatter marks. This is confirmed by the dynamic cutting force simulation, where the specific cutting force, shear angle and friction angle on the rake face of the cutting tool are treated as functions of cutting depth variation. As a result, the vibration energy supply is ascertained for the vibratory loop observed experimentally by this simulation.

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One of the trends of machining in recent years is the strict demands in the systematization of automatic manufacturing for high accuracy and productivity. The commencing of chatter vibration, however, not only makes these requirements harder to satisfy but also causes a serious change in the operation environment. Thus, the establishment of an objective method which can detect the commencement of chatter is the most important and urgent subject for the manufacturing world. In this paper, therefore, to suppress the chatter vibration in turning operation, an experiment is carried out with a specially designed chuck which has a high damping characteristic. To improve the damping capacity, a high-damping material is used for the top jaw of the chuck. The damping effects on chatter vibration are evaluated through theoretical and experimental procedures. Consequently, the applicable condition of a high damping jaw to gain the appropriate damping characteristic is clarified.

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In the previous report, the characteristics of the frictional distance were analyzed assuming that wear amounts between a lapping plate and correcting carrier are proportional to both the relative frictional distance and the working pressure. However, the working pressure applied changes as time passes: therefore, the present paper treats it analytically with wear characteristics of lapping plate by means of the correcting carrier considering the working pressure change. Correcting machining of the deteriorated lapping plate is carried out on the basis of this result. It is confirmed that this method is capable of recovering the accuracy of the deteriorated lapping plate in a comparatively flat manner.

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Single-side straight cutting of aluminum sheets is performed to investigate the effects of inclination angle, tool clearance and cutting-off length on loads, sheared surface qualities and deformation behaviours of the material, where the sheet is inclined with respect to the descending direction of an upper blade. The following facts are found with an increase in the inclination angle. The height of the smooth sheared surface increases when the tool clearance is small. Roll-over depth and height of burr decrease. Shearing resistance decreases as the result of an increase in tension acting in the direction perpendicular to a cutting line. The tension acts throughout the process in shearing of inclined sheet metals even when the cutting-off length is small compared with the sheet thickness.

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The influences of guide pad length of a BTA tool, a longitudinal groove on a rake face of a gun drill and additional rear guide pads of a BTA tool on axial hole deviation are examined. Two new tools to reduce the axial hole deviation are designed, and one of them is produced and used in the experiment to examine the effects. As a result, the following are clarified. The guide pad length is little related to the hole deviation. The longitudinal groove on a rake face of a gun drill reduces the axial hole deviation. The additional rear guide pads of a BTA tool reduce the axial hole deviation. Three rear guide pads are more effective than four in improving hole accuracy. As the new BTA tool is complex in shape and difficult to produce, sufficient accuracy in shape could not be obtained. Therefore, the desired effect that the axial hole deviation is reduced by this tool was not apparent.

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To examine the effects of contact pressure and relative slip displacement on smoothing conditions of surface asperities acommpanied with no bulk plastic deformation of a workmetal, disk specimens were compressed by a punch in a closed die and rotated with the die. A little amount of the relative slip displacement under the contact pressure accelerated remarkably the smoothing of the surface asperities and thereby the workmetal surfaces were smoothed completely to the same surface roughness as the tool. The surface roughness change of the workmetal were approximated by the experimental equations which were expressed as a function of the contact pressure and relative slip displacement. On the basis of these results, smoothing conditions of surface asperities accompanied with bulk plastic deformation of a workmetal were investigated by a free upsetting of disk specimen and an upsetting of ring specimen in a closed die. Consequently, the smoothing conditions of the workmetal surface in these forming processes also could be approximated by the same equations as the above experimental equations.

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This paper describes construction and performance of a prototype machine which was made in order to clarify the effects of surface texture and lubrication on guideways. The prototype machine consists of inverse V-type guideways, a table, a DC servemotor and a ball screw. Scraped machining was adopted on table slide ways. Friction force between the table and guideways, and rising value of the table from the guideways are measured by a dynamometer and a noncontact displacement sensor, respectively. The guiding characteristics were investigated by changing the acceleration curves of the table.

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In this paper, we first propose a design method of lighting equipment using an optical fiber cable that projects a half cone of light on an object and relieves the heating of this object. A sharp edge defined by the line between the lighted section and the dark shaded area can be easily detected by the first order differential procedure of image processing. second, we construct the three dimensional shape measurement equipment which is composed of the proposed luminaire, two cameras and an object table. The outer shape of the object is measured from the multiple images detected by the cameras under the condition that the object table can be rotated, inclined and turned over.

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Group technology (GT) has been considered a key concept to cope with multi-product, small-lot-sized production. One of the advantages of group production is to reduce setup times. It is often much advantageous when the number of parts in a parts family is large and the parts are machined in succession. Generally, when all of the parts in the parts family are assigned to a particular machine (or GT cell), it is difficult to balance the workload among the machines (or the GT cells). In this paper, a procedure is proposed to achieve workload balance among the machines by dividing the parts family into appropriate portions. The machine loading procedure under the balanced workload among the machines is developed to minimize the total production time (sum of group setup times and processing times). Numerical examples are demonstrated to show the effectiveness of the proposed machine loading procedure.

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This paper deals with an interactive system which is able to select mechanisms of mechanical systems in conceptual designs. In this system, there is a heuristic knowledge base of mechanisms which is expressed by membership values and vagueness values based on fuzzy set theory. When design specifications expressed by a frame representation are given, consistency degrees and matching degrees are derived. These two values represent the similarity between the design specifications and the information about various mechanisms in the heuristic knowledge base. By evaluating these two measurements for each possibility, a mechanism is selected for the conceptual design. The effective performance of this system is demonstrated with an example.

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Much difficulty has been encountered in cooperative traction of electric railcars and diesel railcars, because the structure and performance of the respective control systems are very different. Diesel railcars are characterized by more or less constant output from the initial to middle speed range and constant torque beyond the middle speed range. Electric railcars are characterized by virtually constant torque from the initial to middle speed range, with the output decided by notch order beyond the middle speed range. The authors propose a new control system for cooperative traction based upon an entirely new conception. This system changes a general notch order into a suitable notch order for the diesel railcar depending on the electric railcar's speed. The system was mounted on JR's electric and diesel railcars and tested on the main line of JR KYUSYU. Based on this test result, introduction of the system in commercial service was decided upon and practical operation began on April 29, 1989.

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Signal output from a small piezoelectric transducer bonded to a flying head slider is analyzed. Slider-core natural vibrations and slider rigid body oscillations are identified with the frequency peaks of the signal output. These analyses are applied to a highly sensitive contact detection and an evaluation of dynamic characteristics of a slider on a real medium.

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