A new identification technique which makes it possible to evaluate modal parameters such as mass, stiffness and damping coefficient for the nonlinear single-degree-of-freedom system is proposed. The nonlinearity was assumed for the stiffness in terms of the polynomial of the amplitude or piecewise linear property to the amplitude. The technique is based on the fact that the nonlinearity was linearized by the describing function which was developed by the previous investigation. MSF and GDF functions, in which the effect of mass and stiffness, and viscous damping coefficient are independently described in the respective functions, were defined. When the technique was applied, the compliance obtained by the sinusoidal excitation of the system, existence of the nonlinearity and the nonlinearity of the stiffness could be identified in terms of MSF function, and the viscous damping coefficient in terms of GDF function. It was verified that the technique was capable of evaluating the modal parameters much more accurately than the conventional method.

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This paper deals with the effect of damping on the parametric combination resonances of viscoelastic systems subjected to a pulsating generalized Rent force. The effect of the direction factor of a generalized Rent force on the parametric resonances is investigated. The effect of an external and internal damping on the critical excitation parameter and the width of resonance regions is examined quantitatively.

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The noise from thin gears is dominated by the vibration in an axial direction of gears. This paper presents a method for analyzing the coupled vibration of a rotating gear pair. The vibration of each dear is expressed as a series of the eigenfunctions which are given in the form of rotating waves. The frequency equation is derived from Mindlin's plate theory by using the receptance method. The analysis indicates that vibration modes of the rotating gear pair are fixed in space. Some numerical examples are presented, and the experimental results are shown to be in good agreement with the theoretical ones.

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We examined the vibration response characteristics of two circular cylinders in tandem, with a pitch-to-diameter (p/d) ratio of 1.5, subjected to two-phase cross-flows. The average bubble size was from 3.0 mm to 4.0 mm for a small-bubble two-phase flow and from 6.0 mm to 7.0 mm for a large one. Experiments were carried out to obtain the vibrational response of the circular cylinders for both bubble sizes, changing the void fraction from 0% to about 30% at various velocities ranging from 2 to 8. The experiments showed the following major results: 1) In tandem cylinders with p/d=1.5, air bubbles caused the cylinder system to excite vibratingly when the flow velocity was smaller than that producing the lock-in state in the two-cylinder system; 2) the response characteristic map in terms of void fraction and reduced velocity was made to investigate the effects of air bubble size on the tandem-cylinder's vibration; and 3) the smaller bubbles had less effect on the vibration response of the tandem cylinder system with respect to the reduction and excitation of vibration.

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This study concerns the occurrence of the so-called fluid-elastic vibration of the tube array. The theory is based on approximate fluid dynamics in which the fluid force acting on a tube is computed using the pressure distribution on the cylinder surface and combined with the movement of the tube itself. The estimation of the separation point reveals an important role in this analysis and the calculated results show agreement with an experimental data.

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The unstable vibration of the tube array, which is called the fluid-elastic vibration and is caused by cross flow, is analysed using a time-history simulation calculation which is based on a simple assumption for the fluid force combined with the movement of the tube itself as shown in the previous paper. This time-series calculation gives us a computation for the impact vibration. The computed results are compared with the measured impact force and are expanded to a steam-water two-phase flow.

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The first approximation of the stability boundary for the fluid-elastic vibration of a tube array caused by a cross flow was reported in the first report. However, the time-series analysis given in the second report shows that the relation between the critical flow velocity and the initial amplitude shown in the first approximation cannot exist. Thus the further approximations for the estimation of the fluid force have been examined here, and a more reliable method is reported. In addition, the effects of some parameters which were introduced into the estimation of the fluid force are also examined in this report.

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The fluctuation of flux density and shape effect of conductor slab on an electromagnetic damper, which consists of rectangular magnetic poles and a conductor slab, are clarified by the finite element anaysis and an experimentation. Firstly, we measured the flux density distribution near magnetic poles by the use of Hall elements, while the conductor slab vibrating in the magnetic field. The result verifies the numerical result in our first report. Secondly, attenuation coefficients were obtained under several dimensional ratios of conductor slab to magnetic pole, experimentally and numerically. The experimental result agreed well with the numerical result. Thirdly, a relation between conductor shape and eddy current distribution is also discussed numerically.

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The optimum shape of a conductor slab on an electromagnetic damper is determined by an optimization technique by the use of the Lagrange method of multipliers taking a serious view of a compact design. Firstly, damping coefficients were obtained by analysis of the eddy current in the conductor slab by the boundary element method combined with the finite element method. The numerical result agrees well with the experimental result in our previous report. Secondly, the optimum dimension of rectangular conductor slab was obtained by the least-square method and the optimization technique. The result of the optimization is verified in good agreement with the result of the least-square method. Thirdly, the optimum shape of conductor slab determined by the optimization technique. Furthermore the result is verified by an experimention.

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An sensitivity analysis method for the eigenproblem of coupled acoustic-structural systems is proposed, which is to be applied for reducing the vehicle interior noise. At first the conception of the left eigenvector and right eigenvector with regard to coupled acoustic-structural eigenproblems is introduced, and four propositions concerning this conception are then proved. On the basis of these propositions, the formulation of the eigenmode sensitivity analysis is obtained. The eigenmode sensitivity formulations are applicable to the change of structural parameters, acoustic parameters and acoustic-structural coupling conditions respectively. By estimating the calculation error of this method theoretically, a guideline of the design variable change limit is shown. The theoretical results and computation formulations are demonstrated through a cubic shell interior noise problem.

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The objective of this study is to evaluate the accuracy of the solution when the response to an external force is solved by time integration methods. As the first step toward this goal, a method to evaluate the accuracy of the time-integration method to sinusoidal input was proposed in the first report. Based on this method, some famous time integration methods were evaluated. The evaluation results are shown in this paper.

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A method to estimate the dynamic reliability of structures under combined time varying loads is investigated. The response statistical moments of multi-degrees-of-freedom structures are obtained by modal synthesis technique and stationary random vibration theory. The formulation is demonstrated for three dynamic load cases which are; (a) both with nonzero mean; (b) both without nonzero mean and (c) with/without nonzero mean. Furthermore, first passage probability considering stochastic load combinations is derived by the load coincidence method under the assumption of a Poisson process for threshold crossings. The uncertainties of power spectral densities pertinent to loads as stochastic processes, are also considered through the derivation of first passage probability. This paper, as a 1st report, describes the formulation of dynamic reliability against the limit states defined by response displacements.

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A method to estimate the dynamic reliability of structures under combined time varying loads is investigated. The response statistical moments of multi-degrees-of-freedom structures are obtained by modal synthesis technique and stationary random vibration theory. The formulation is demonstrated for three dynamic load cases which are; (a) both with nonzero mean, (b) both without nonzero mean and (c) with/without nonzero mean. Furthermore, first passage probability considering stochastic load combinations is derived by the load coincidence method under the assumption of a Poisson process for threshold crossings. The uncertainties of power spectral densities pertinent to loads as stochastic processes, are also considered through the derivation of first passage probability. This paper, as a 2nd report, describes the formulation of dynamic reliability against the limit states defined by structural integrity.

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This paper treats a shape determination problem of structures subjected to a moving load. Either strain energy or kinetic energy are employed as an objective function, which is minimized to obtain the optimum shape of the structure under the condition that its volume is constant. In order to obtain strain and kinetic energies, modal analysis and Duhamel integration are adopted. Shapes are refined in an iterative way called Energy-Ratio-Method. Some numerical examples of beams subjected to a moving load with constant speed are shown and examined.

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It may sometimes happen that a rotating machine can not be operated beyond a critical speed if it does not have sufficient power supply. Even if it can be operated beyond the critical speed, it yields a large transient response due to the limited power supply. An optimum design of an operating curve with limited power supply to obtain the minimum transient response was studied in the previous report where the operating curve was expressed by a pieccewise linear curve with a stationary part and two parameters specifying the stationary part were to be optimized. The same type of optimum design problem of an operating curve is considered again in this report. An operating curve of general form is expressed here by the cubic spline function and the position vectors defining the spline function are optimized to minimize the transient response around the critical speed. Several numerical examples are obtained and examined from many points of veiw.

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The handtool discussed in this paper is a kind of adjustable wrench which is roughly of the same type as the widely used monkey wrenches and pipe wrenches. In order to establish design methods, fundamental characteristics of this kind of adjustable wrench were theoretically studied. The wrench was modified as a linkage having five straight links. Three clamping forces acting on a circular cylinder as a bung were calculated numerically by means of the electric computer when varying the diameter of the circular cylinder and the length of two of the five links. As a result, fundamental characteristics of this type of adjustable wrench were ascertained in this paper.

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This paper describes the design and operation of an excess air-ratio sensor, with an electrically heated solid oxide electrolyte, for internal combustion engines. To minimize the exhaust-gas temperature dependence, electrodes are provided only in the heated region with an electrolyte thickness of 1 mm. The heater is controlled to maintain a constant internal resistance of the electrolyte. With this new sensor, the λ range of 0.5 to 1.6 can be covered with sufficient accuracy in the exhaustgas temperature range of 655 K to 850 K.

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An orthogonal learning method is applied to pattern recognition using a multilayer neural network. Numerical simulations of neural networks are performed for recognizing plural numbers of 20-bit and 256/bit character patterns using standard three-layer networks composed of one intermediate hidden layer and input and output layers. It is confirmed that the initial synapse weights greatly influence the convergence of the learning process. Furthermore, high-order functions such as, the problem of counting the number "1" in a 4- and 6-bit binary patterns and the problem of classifying the number "1" in 9-bit patterns into 2 groups are investigated. It is shown that the convergence of learning is one of the most fundamental neural network problem to be overcome. A new learning method is proposed for accelerating the convergence of training of a neural network. The effectiveness of the new learning method is verified.

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This paper discusses the regulator problem of minimizing the input energy for the multi-input linear time-invariant discrete-time system with the zero terminal state. The performance index is the sum of the quadratic forms of the input vectors. By using the deadbeat principle, the system is transformed into the new time-variant system with the time-variant structure of the new input. The performance index is transformed into the sum of the quadratic forms of the new state vectors and the new input vectors with cross terms, and the new terminal state is free. The optimal inputs are given by the variable gain state feedback in the first phase, by linear combinations of the constant gain state feedback and the variable gain state feedback in the second phase, and by the constant gain state feedback in the third phase. The variable gains are obtained by using the special Riccati equation. Both gains are independent of the initial state.

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Eliminating brake noise generated during brake application is an important subject for the improvement of comfort in a car. This noise can be caused by two different phenomena: the high-frequent brake squeal (frequency 1-15 kHz) and the low frequent brake groan (200-500 Hz). We presented two researches on brake squeal at the 1st and the 2nd reports. We have made research into the low frequent brake groan, so as to study the method of eliminating brake groan. We considered the analysis model, in order to clarify the cause of disc brake groan. We obtained the equation which represents E, the increase of kinetic energy during 1 cycle. Brake groan is generated under the condition E > 0. The factor, having influence on brake groan, was clarified by considering the above equation of E.

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Eliminating brake noise generated during brake application is an important issue in the improvement of comfort in a car. We presented the research on the low frequency groan noise at the 3rd report, using the mathematical model without damping. At this paper, we considered the improved model with damping in order to eliminate disc brake groan. According to the above considerations, disc brake groan can not be eliminated by nondimensional damping B ≤ 10^-1. And disc brake groan generation is increased by damping order B=10^-1. Furthermore, disc brake groan generation can be reduced by damping B ≥ 1, depending on the ratio of two damping factor.

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Eliminating brake noise generated during brake application is an important issue in the improvement of comfort in a car. This noise can be caused by two different phenomena : high-frequency brake squeal (frequency 1-15 kHz) and low-frequency brake groan (200-500 Hz). We presented two studies on brake squeal in the 1st and the 2nd reports, and we presented a study on disc brake groan in the 3rd report. We considered the theoretical analysis on these brake noises. The equations of motion are represented by the same equation, and we obtained the equation which represents E, the increase of kinetic energy during 1 cycle. According to these analyses, drum brake squeal, disc brake squeal, and disc brake groan are generated by the same cause.

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Since most of the traffic accidents caused by road vehicles result from human-error, in order to curb the increasing number of accidents, it is inevitable that a hazard-control system for human-error be materialized for road vehicles. If a failure of such a system, however, brings about an accident, the makers of the system can be sued. Thus, the system should be not only fail-safe and/or fault-tolerant, but also structured with a counter-locking mechanism to prevent the system from causing a second accident. In this paper, first, hazards, which are typically produced by human-error, are identified using the A-C model. Second, the backup systems to control the hazards and the counter-locking mechanisms are structured systematically, based on the dissociation theory of action linkage. Last, the relationships between the fail-safe and fault-tolerant structures of the backup systems and counter-locking mechanisms are defined.

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In the previous paper, the authors proposed a torque control method using a microcomputer control that would be effective to reduce the vibration of a rolling piston-type compressor for a room air conditioner. This paper deals with the experimental results of the torque control method. Two types of feedback forms, "rotational speed feedback" and "rotational acceleration feedback", were compared for stability and transient response. It was proven that both feedback forms were effective in reducing rotational variation and vibration of the compressor chamber. However, "rotational speed feedback" needed complex compensations for stable control and response was slower than that of "rotational acceleration feedback".

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Since Present NC machines invariably use proportional control, there is a large time lag intrinsic to this control. Consequently, in the state of simultaneous plural-axes control, a locus-error proportional to the movement speed inevitably results. Since this servo lag error is dependent on proportional gain and acceleration/deceleration time constants after interpolation and machine rigidity this system parameter adjusts for each machine in advance and interpolates the NC data that are input while always making optimum gain-compensation and phase-compensation on the said NC data. This has completely eliminated the servo lag error which had been resulted from the high-speed process. For example, when this system is combined with machining center HA-5VA, it can move on a steep curve up to R5mm with the tool center locus at a tangent speed of 6m/min without any servo lag error. In addition, as a result of incorporating the above compensatory method, this system identifies the acceleration/deceleration of the response output with high precision. This allows the system to perform automatic acceleration/deceleration without any redundancy, using 100 % of the servo actuater's power.

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This paper outlines the development of a simulation method which predicts the handle torque of an electrically assisted power steering system. The electrically assisted power steering system would provide benefits for fuel economy and flexibility in controlling the handle torque. A DC motor with torque sensory feedback is used in this system. However, the DC motor tends to cause torque fluctuation and the feel of rough handling. In order to reduce torque fluctuation, an equation of motion with a 5-degree of freedom model has been formulated for analysis on the electrically assisted power steering, and the methods of controlling the handle torque have been investigated. Feasibility experiments and simulation results show that the simulation method is effective for developing an electrically assisted power steering system.

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The authors have developed a new type of parallel bicycle which can vary its configuration and change locomotion mode according to the working conditions or circumstances. The fundamental components of the vehicle are an inverted-pendulum-type parallel bicycle, a working arm and a controlling arm. By combining the components, three kinds of the configurations can be realized : a parallel bicycle with a working arm and an L-shaped controlling arm, a double-steered wheeler with a controlling arm, and a four-wheeled vehicle with a working arm. This paper describes the control methods of motions obtained with the first-type parallel bicycle with a working arm and an L-shaped controlling arm, and experimental results. The postural and driving control using the controlling arm is very useful and the motion of the working arm is well controlled by it. When an auxiliary wheel is installed at the tip of the working arm and the arm is lowered until it touches the ground, the vehicle is converted into a tri-wheeled car. Conversion from the two-wheeler to the tri-wheeler and the inverse conversion are also successfully attained by the intelligent control method proposed here.

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Theoretical studies on the dynamic stability and the active Control of a cantilevered beam under a transverse follower force due to a fluid jet are presented in this paper. In order to stabilize the cantilevered beam, the active control force is derived from the bending moment produced by a piezoelectric actuator partially attached to the beam. The equations of motion afe reduced to a finite degree-of-freedom system with Galerkin's method. A control law is determined using the optimal regulator theory. Through the numerical calculations for various conditions, the effects of the internal viscous damping of the beam, the mass, rigidity, length and the location of the piezoelectric actuators on the stability of the uncontrolled beam are clarified. Moreover, the optimal location, mass, rigidity and length of the actuator for the control are discussed.

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In this paper we discuss a method which improves the characteristics of the position control by widening the temperature range of the martensitic transformation of SMA (shape memory alloy) actuators. We take note of a difference in the martensitic transformation temperature of the TiNi alloy after different heat treatments. Then a TiNi alloy is treated with the furnace of a temperature range of 400-500°C. As a result of this treatment, the SMA having sloped martensitic transformation temperature is obtained, and the temperature range of the martensitic transformation of this alloy is 30°C wider than previous techniques. The improved SMA can be applied to robot actuators.

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This paper deals with a new type of mobile robot, the "Brachiation Robot", that makes use of the swing of the pendulum due to gravity, and shows a simulation method with some results of its continuous mode during one period from the initial static condition to compute one cycle of the transfer motion. The difficult problem to be solved in this study is to show the simulation method for the discontinuous motion, since the brachiation motion involves the switching of the swing. supporting arms as a monkey exhibits in branch transfer motion. This paper shows a computational method of this discontinuous motion, so that it becomes possible to evaluate such an oscillation effect during a period of brachiation motion, including the motion behavior and consumed energy depending on motion modes. In particular, this paper clarifies the dynamics and the joint selection in the proposed brachiation robot model, by which the oscillation can be easily generated due to the resonance frequency of the robot structure. The difference of upper and lower directional swing motions of arms as "brachiation" is also given in the comparison with the consumed energy. Thus, this paper gives some insight for desigining the structure and control method of a new brachiation type of robot.

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In this paper, a methodology using Lyapunov direct method is proposed to analyze the stability of a 1-DOF manipulator system which is positioned on a stiff wall with collision phenomenon. The stability and response of the system are examined by parameter studied of numerical simulation. As collision is a phenomenon with energy loss, it is effectively used in the industrial field to suppress vibration. However, in the robotic field few studies have shown the control of robotics with collision, and systems are controlled to avoid rapid contact. We have adopted a Herz-type model with energy loss parameter to express the impact force between the manipulator and the wall. Using this model, we proved the stabilization effect of collision using a Lyapunov function. The effect is confirmed by the simulation. As a result, stable positioning of the manipulator on stiff wall is assured.

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In this paper, a new concept of a "neural servo controller" is presented to show the applicability of the neural network to the position and force control of robotic manipulators. The proposed neural servo controller is based on the self-organization capability of the neural network, which here consists of two hidden layers, and input/output layers. The controller can adjust the neural network ou-put to the robot in the forward manner to cooperate with the feedback loop, depending on different characteristics of handling objects. In particular, the neural network can recognize the force used to adjust the hybrid control ratio between the position and the force control modes. The proposed method can adapt the network to stabbing control as one of applications of the position and force control. Simulations as well as experiments are carried out for the case of one-dimensional robotic manipulators. The results show the applicability and adaptability of the proposed neural servo controller to the position/force control of manipulators.

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This paper deals with the sensing planning for a pipeline inspection and the maintenance robot, by which the robot can carry out inspection tasks to detect a malfunction location in a plant pipeline system autonomously. For this purpose, the robot needs knowledge of the plant map, plant function and plant diagnosis. In the previous report, the path planning expert system (PPES) was reported; if the plant map is given, the robot can automatically produce the path to reach a location from another location within the robot task level. In this paper, PPES is modified to adapt the sensing planning expert system (SPES) and generates executable robot commands for motion control. In addition, the plant knowledge system requires more information concerning plant operation states, such as standard value/status and up/down stream. Furthermore, the robot needs knowledge on inspection/repair and diagnosis, so that the robot can estimate the malfunction candidates and select one individually after some inspection trials. Together with PPES and SPES, the robot becomes intelligent enough to carry out given inspection tasks automatically.

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This paper deals with the new mechanism of a new maintenance robot, Mark IV, following the previous reports on pipeline inspection and maintenance robots of Mark I, II, and III. The Mark IV has a mechasism capable of inspecting surfaces of storage tanks as well as pipeline outer surfaces, which is another capability of the maintenance robots, different from the previous ones. The main features of Mark IV are as follows, (i) The robot has a multijoint structure, so that it has better adaptability to the curvartures of pipelines and storage tanks. (ii) The joint of the robot has SMA actuators to make the robot lighter in weight. Some actuator shape characteristics are also examined for the robot structure and control. (iii) The robot has suckers at both ends, so that the robot can climb up along the wall from the ground. (iv) A robot with the inch worm mechanisms has many functional motions, such that it can pass over flanges and T-joints, and transfer to adjacent pipelines with a wider range of pipe diameters. (v) A control method is given for the mobile motion control. Thus, the functional level of the maintenance robot has been greatly improved by the introduction of the Mark IV robot.

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This paper discusses the suitable positions of two wholly turnable arms and an efficient procedure of rotations and passes for changing the position of an object. The position has three degrees of freedom. Firstly, this paper deals with the reachable region of the direction of the object face that has two degrees of freedom by means of the two-arm operations under the conditions that the relative angle of arm directions is fixed and that the object is passed N times and rotated N+1 times. The results are that the angle of 90 degrees is suitable as the relative angle of arm directions and that three rotations are sufficient for an arbitrary changing of the direction of the object face. Secondly, this paper shows that three rotations are also sufficient for an arbitrary change of the object position, and it also shows the procedures.

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Although many algorithms of optimum trajectory planning for manipulators have been proposed, the efficient ones which treat the general cost problem have not necessarily been obtained yet. This paper treats this general trajectory planning problem which includes the optimization of a spatial path. The proposed method is divided into two stages. One is the optimization of time trajectory with a given spatial path. For this part some efficient algorithms have already been proposed. Therefore, we use one of these algorithms in our method. The other is the optimization of the spatial path itself. To consider this problem, we represent the manipulator dynamics using a path parameter 's', and we solve this differential equation as a two-point boundary value problem. In this procedure, the gradient method is used to calculate the improved input torques. The advantages of the proposed method are the following. (1) It is easy to satisfy the given boundary condition because the dynamics is represented by the path parameter`s' which is not directly related to time. (2) The algorithm takes the form of a feasible method, thus we may stop the calculation when we get the desired accuracy of a solution. Finally the proposed method is applied to a manipulator with two links. Numerical results of the example show the effectiveness of this method.

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A flexible microactuator with 3 degrees of freedom was developed for micromanipulators. The device was made of fiber reinforced rubber (FRR) and its deformation controlled by an electrohy-draulic or electropneumatic system. This report deals with its dynamic characteristics from a practical point of view. First, a transfer function of the actuator is derived theoretically, considering (1) a fundamental frequency of FRR, (2) compressibility of working fluid in the actuator, and (3) friction of tubes between the actuator and control valves. Secondly, step responses of the prototypes are shown under various conditions. The response time is about 0.1 (s) with small tube friction, or 3(s) with large tube friction.

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This paper is concerned with a stochastic model reduction of a refrigerator system. Firstly, the mathematical models for a refrigerator system already established are briefly reviewed. Secondly, taking into account the parameters with physical significance, steady state response and the errors in the reduced model, a model reduction approach is proposed. Finally, it is shown that the proposed approach is a type of dominant pole technique.

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Recently, spiral bevel gears have come to be used widely as transmission gears of motor cars, and the majority of these spiral bevel gears are of the Gleason-type (tapered tooth depth). However, many problems still remain to be solved. Therefore, it is one of the most important subjects in the motor car industry to find an effective spiral bevel gear. The Oerlikon-type spiral bevel gear (constant tooth depth) is a promising gear which meets this requirement. However, there have been very few studies hitherto which deal with the dynamic behavior of Oerlikon-type spiral bevel gears. Under present day situations, the dynamic behaviour of the Oerlikon-type spiral bevel gear was chosen as a subject of our studies, that is, the tooth root stresses and vaibrating amplitude of gear housing under various running conditions were examined, and the influence of tooth bearing upon the tooth root stresses was discussed. In this study, the dynamic behaviour of the Oerlikon type spiral bevel gear was clarified, and it was found that adaptation of the Oerlikon-type spiral bevel gear for the transmission gear of a motor car is effective.

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In their previous study (1st report), the authors have demonstrated that noise can be reduced greatly by using gears which are made of plastic material (called P-nylon) consisting of nylon filled with a plasticizer. In such apparatus as audio equipment, gears suffer only a slight torque and their teeth do not have to be high in strength. Currently, the development of gears with low noise has been demanded in this field. In the present study, gears are produced using a polyamide elastomer which is softer than P-nylon and harder than rubber, and tests are callied out to determine their noise reduction effect, wear of their teeth and their working life. The practical performance of the gears is studied based on the test results.

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The experiments with regard to the effect of an eccentric phase angle of the pulley were made for a transmission error in a synchronous belt drive with an eccentric pulley in the quasi-static condition under an initial tension, and these experimental results were compared with the computed results. The eccentric phase angle of the puley has a large effect on the transmission error. In order to maintain a small transmission error, the belt should be set up such that the eccentricities of the driving and driven pulleys cancel each other. When there is a meshing phase angle at the beginning of the meshing of the driven side, the transmission error having a period of one pitch of the pulley is decreased when this phase angle approaches zero, and the meshing phase angle exerts almost no influence on the transmission error having a period of one revolution of the driving pulley. Further, it was found that the amplitude of the transmission error having a period of one revolution of the driving pulley remains nearly constant regardless of the size of the belt width when the initial tension per unit width is the same.

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The static and dynamic performance of a seal ring which is deformed elliptically is investigated. When the angle between the long axis of ellipse and the eccentricity axis is larger than 90° and less than 180°, the ring can be made stable. Also, the ring will be more stable when the angle between the long axis of ellipse and the basis line is suitably selected and when the angle between the gravity direction and the basis line is 90° or 180°. An elliptically deformed seal ring which is always stable is easily designed by using the characteristic figures presented in this paper.

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The elastic-plastic analysis based on a combination (FEM+BFM) of the finite element method (FEM) and the body force method (BFM) is applied to the elastic-plastic analysis of the subsurface layer under cyclic pass of rolling-sliding contact loading. Two types of hardening rule are assumed. One is the isotropic hardening rule (IHR) and another is the kinematic hardening rule (KHR), i. e. Prager rule. If the material obeys IHR, so-called shakedown phenomenon is induced during the early cycle of pass of loading. On the other hand, if the material obeys KHR, the quasi-steady cumulative forward flow develops at the load level of q₀/k≃7, where q₀ is the peak Hertzian pressure and k is the shear yield strength in von Mises' yield criterion. No apparent difference is found in the cyclic increment of the equivalent plastic strain range Δε^^-_p in the subsurface layer for the coefficient of friction=+0.1 and -0.1. The amount of the experimentally observed forward flow was more than the numerical results for IHR and less than those for KHR.

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The stress and temperature distributions in the hot rolling of aluminum have been measured using stress and temperature sensors which have been developed by the authors. It has been determined that heat flux increases rapidly at the entrance of the roll gap and then gradually decreases along the contacting arc. The heat flux and surface temperature measured by the sensor have been used to estimate the temperature decrease in the workpiece. It is expected that the measurement of heat flux may be useful for the study of lubrication in hot rolling. From the results of the stress measurement, the ratio of the frictional stress in the width direction to the pressure has been found to be greater in hot rolling than in cold rolling. This may be related to 'the fact that the width of the rolled specimen in hot rolling is larger than that in cold rolling. Problems related to errors in stress measurement due to the heat deformation of the roll surface around the stress sensor in hot rolling are discussed.

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The purpose of this paper is to investigate quantitatively the cooling action of grinding fluid which actually exisits in the microgap of the wheel-work contact area. For this purpose, a sensing probe for measuring the film thickness of the grinding fluid in the contact area was used. The results obtained here are summarized as follows: (1) The cooling action of grinding fluid in the contact area was estimated numerically from its mean film thickness. Generally, the larger the mean film thickness is, the more effective its cooling action becomes. Zero to fifty percent of the grinding heat generated in the grinding could be absorbed into the fluid film. (2) The thermal boundary layer should exist in the fluid film flowing over the grinding heat source at high speed. So, too large film thickness exceeding the thermal boundary layer is not necessarily effective for cooling the grinding temperature. (3) In order to improve the cooling efficiency, it would be a useful countermeasure to increase the thermal boundary layer if compared under the same grinding speed, specifically speaking, by the adopting such technique as using cold grinding fluid.

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The examination on the phenomena which occures between cutting edge of bite and worked surface in the wet turning was conducted. As the results, it was found that similar phenomena occur even when the kinds of cutting fluid were changed. Moreover, it was found that the contributions of extreme pressure additives of cutting fluid, or the diluting rate of water-base type cutting fluid to the effects on the phenomena which dete riorate worked surface.

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The relationship between deflection of a boring bar and axial hole deviation is examined theoretically and experimentally using a BTA tool. As a result, the following are clarified. The hole deviates toward the inclination of a boring head fixed on the end of a boring bar. The inclination is caused by the deflection of the boring bar due to bar weight and hydraulic pressure of the cutting fluid. The deflection due to the bar weight changes according to the condition in which the boring bar is supported. That due to hydraulic pressure is classified into the following two cases: one caused by supply of the cutting fluid at the oil pressure head, and another caused by hydrodynamic pressure when the boring bar deflects and approaches the hole wall.

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The main object of the present paper is to discuss cutting temperature of the drill point in low frequency vibratory drilling of SUS304. Although many studies dealt with the drill wear in conventional drilling have been presented, there has been hitherto no study dealing with cutting temperature of the drill point in low frequency vibratory drilling of SUS304. For this reason, cutting temperature of drill point in low frequency drilling of SUS304 was chosen as a subject of our studies, that is, cutting temperature at the drill face was measured by using of some cobalt high speed steel drills which brazed a sheathed thermocouple, and the experimental results were compared with those in conventional drilling. On the other hand, cutting temperature of drill point was computed by finite element method. From this study, distribution of cutting temperature of drill point was clarified.

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The applications of a new cut-off tool equipped with a grooved rake face are discussed in relation to the cutting performance compared with that of the conventional (flat rake face) cut-off tool. The experimental results indicate the following: 1) cutting surface roughness and chip disposal are improved, and cutting forces are decreased; 2) cutting forces and their fluctuations are markedly decreased as the oxygenjet is supplied to the tool edge at the range of cutting speed that the built-up edges grow; 3) the ceramic cut-off tool is capable of grooving steel work, as the cut-off tool has a grooved rake face and the oxygenjet is supplied to the tool edge.

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The sintered carbide tool is commonly used in various manufacturing operations, and it is chosen as the object of this research. Under the commonly used cutting speed, some ultra short-time cutting operations, (about 0.006-0.02 seconds) are performed, and the behavior of the formation and propagation of damage in the early stage of cutting is investigated in detail through the observation of worked surfaces and the cutting edge. Consequently it was clarified that no visible damage is formed at the end period of the rubbing region, and beyond the dug-up region damage is formed and propagates very quickly. Furthermore a very convenient method of evaluating the quantity of the damage at the beginning of the cutting region with chips is Proposed.

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