In the case of sculptured surface NC machining, NC data are constructed with sequential NC blocks instructing a small movement of less than 1 mm. In order to realize high-speed processing of enormous volumes of NC data, a high-speed data communication interface and a NC adapter which can generate servo data in the binary format have been developed. However, if the curved interpolation function is implemented in the CNC controller, these equipments will be unnecessary. Further-more, if the tool path can be generated in the real-time mode, intermediate processings like NC data storage and format conversion will be shortened. The CNC system described in this paper has two functions : real-time tool path generation and curved interpolation. It can accept geometrical data and generate tool path automatically. All cutter location data are directly input to the servo process. This controller realizes the same machining style as a copy milling machine which are real-time machining in shop floor and also high operationability and high-accuracy machining. These features will improve productivity of molds and dies.

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In milling and drilling of heat-treated steels, such as die steels and high speed tool steels, machining a number of grooves or holes often causes severe wear or chipping of carbide tools. In order to machine hardened work materials with ease, new composite coatings and new shapes for carbide endmills and drills have been developed. (Al, Ti) N coatings deposited by cathodic arc ion plating exhibited higher hardness and higher oxidation resistance than those of TiN coatings, and new hard-type shapes yielded improved chipping resistance. These newly developed coated carbide cutting tools were evaluated through machining of various hardened work materials, and showed greatly improved performance, especially for high-hardness work materials.

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In this paper, a method of lubrication by means of oil mist which is intermittently supplied is proposed for machine tools and its performance is investigated experimentally. The temperature rise of the outer race of the angular contact ball bearing used is mainly measured changing the type of bearings and lubrication conditions. Also, the temperature of the bearing housing was controlled to reduce the temperature rise of the bearings. From the experimental results, the following conclusions are obtained. The proposed lubrication method is surerior to oil-air lubrication which is currently in practical use for high-speed machining centers, and the smaller ceramic ball of the bearing induces lower temperature rise. Cooling of the bearing housing is not effective in the high-speed range over 10000 revolutions per minute where the dn value is exactly equal to 10⁶. In addition, the direction of the nozzle relative to the bearing greatly influences the temperature rise of the bearing.

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The edge fracture of diamond grains plays an important role in cutting of stone, concrete and refractories. In this paper the edge fracture characteristics of two kinds of diamond grains were evaluted on the basis of facture onset coefficients and edge shape transition probabilities, which were obtained by a single-grain grinding test. These probabilities enabled us to calculate the edge shape distribution of these diamond grains in stone grinding processes. The results obtained are summaraized as follows : (1) Since the diamond grinding grains used have small fracture onset probability and large probability transition to sharp edges, their grain edges meintain sharpness by fracture for a long time during grinding. (2) The stationary edge shape distribution of MBS 760 contains 28 percent more sharp edges than that of MBS. Consequently MBS 760 grains, which have ideal fracture characteristics, are suitable for grinding hard stones.

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The high-speed dynamic punching technology to produce circular holes perpendicular to the plane surfaces through the thicknesses of ceramics specimen plates was investigated. The specimens were sandwiched between a pressure plate and a die of a punching jig and were pressed on both the top and bottom surfaces. High-speed stresses given by a dry ice flier delivered from a gas gun were applied by a columnar punch to the specimens and the holes were produced by shearing between the edges of the punch and the die. The specimens were punched feasibly by the constant surface pressure with most size of the clearance between the punch and the die in the radial direction, but the pressure increased rapidly as the clearance approached zero. The characteristics of the profiles on sheared surfaces for the thickness direction, electron fractography of fracture surfaces and strength of the punched plates were examined. The stress was analyzed by the finite-element method to discuss the relations between shearing stress distributions and the profiles or to examine the relation between the surface pressures and moments of shearing stresses through the thicknesses of the punched surfaces.

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The study deals with ultraprecision 3-dimensional shaping by means of a lathe-type milling machine. To set a rotational tool at an arbitrary position within the working space, the polar coordinate system transformation is used to change sets of the 3-dimensional position data, given as workpiece shape data, to the combined motion of the main spindle orientation (C-axis) and the translational movement (X-axis) as well as the motion of the tool (Z-axis). Two kinds of rotational tools are provided : one is a pseudo-ball-end mill to carry out ultraprecision micromachining, and the other is two oblique fly-cutting tools to increase the cutting speed. From the experimental results, it is found that the lathe-type milling machine can perform ultraprecision micromachining and 3-dimensional shaping.

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Advanced ceramics are becoming widely used today for the mechanical components. However, it is quite difficult to machine these materials because of their high strength, hardness and brittleness. In order to increase the machining ability, the high pressure coolant is supplied to the cutting area from inside of the cutting tool through the tool holder and the spindle of machining center. For this mechanism, the side-through rotary union which transfer the coolant into rotating spindle is required, and so far the mechanical seal rotary unions have been applied. It is, however, considered to be difficult to apply the mechanical seal rotary unions under high speed rotation and high coolant pressure. In this study, a rotary union which use the hydrostatic pressure of coolant is proposed as one of methods to improve the performance of machine tools. The performances of developed rotary union are theoretically and experimentally investigated.

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The simulation method to analyze the properties of a ground surface layer was proposed based on FDM and FEM. In order to analyze the properties, the flow stress characteristics equation of the material ground was discussed, in which strain rate, temperature and their histories were included. The effects of the flow characteristics of the ground surface properties were discussed. It was clearly shown that the residual stress distributions on and after grinding were under estimated by the analysis using the flow stress equation without temperature effect.

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In order to control cutting force and its direction, a combined milling head was newly developed. This head has two milling cutters which rotate in opposite directions, and a meshing phase of cutters is also variable. The cutting performance of the head was discussed based on the cutting mechanism of a single milling cutter, and a method for simulating the performance was proposed. Cutting force, its change and direction are greatly affected by the change of the ratio of depth of cut for each cutter and the change of the meshing phase. Using the numerical simulation of cutting performance of the head, the optimal cutting conditions, such as the ratio of the up/down cutter's depth of cut and the phase, can be determined. The simulated performance and the experimental one show good agreement.

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In order to realize a feed rate of 20 m/min for cutting operation of mediurn-and large-size machine tools, a new high-speed and high-accuracy feed drive system which has a servo-motor and ball screw combined with a hydraulic actuator has been developed. The previous papers clarified that this system is able to drive a table, weighing about 1 ton, ten times a fast as the conventional rate with considerable accuracy. This paper deals with the improvement of the hydraulic system which has an unfavorable time delay. The experimental results show that the time delay of the hydraulic system was reduced to one-sixth of the previous amount, and accuracy of circular interpolation for a 150 mm radius was improved to 149 μm at a feed rate of 20 m/min. This amount is smaller than for the previous system by about 100 μm

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Rolling guideways have been widely applied to the machine tool tables because of their low friction and high maintainability. Table systems with rolling guideways have, however, some demerits such as low damping ability, which causes the chatter vibrations during machining. In this study, a table system with variable damping mechanism is proposed in order to improve the dynamic characteristics of the table system. The ER (electrorheological) fluid is applied to control the viscous damping force generated by the proposed mechanism. ER fluid is a kind of colloidal suspension, and its apparent viscosity is increased in accordance with applied electric field intensity. The dynamic characteristics of the proposed table system are analyzed by means of the impulse force method, and the effect of ER fluid is investigated.

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A paper converting single-facer occasionally experiences alternate pressing marks at the operating speed of about two times the resonant speed of the roll system. This paper describes the theoretical approach to this phenomenon based on the hypothesis in which the roll vibration system is expressed by Mathieu's equation with variable paper spring constants. Paper spring constants are calculated for each rotational angle to show that the range of its primary component is nearly equal to 60 percent of the average range. Investigation the characteristics of Mathieu's equation and the experimental results, it is demonstrated that the instability is expected to occur above the operating speed due to parametrically excitated vibration. According to the above-mentioned mechanism, some preventative methods for the unstable vibration were shown quantitatively and their practicality was confirmed.

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One of main causes of poor sound quality in a passenger car is the high contribution of relatively low-frequency half-order multiple components of the in-line 4-cylinder power-train vibration, principally 2.5 and 3.5 order of engine rotation. In order to identify the excitation mechanism for the half-order power-train vibration, the excitation forces raised by inertial force and torque fluctuation were investigated. The results can be summarized as follows. Since half-order multiple rolling moments caused by the torque fluctuation have a different working point and a different phase angle in each cylinder, the combined torsional moment acts on the cylinder block around the crankshaft axis as an internal force, and hence the torsional vibration shape is excited as half-order multiples of engine rotation. This theory has been proven by the experimental operating deflection shape analysis.

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In order to develop a periodical motion mechanism with high robustness against the variation of system parameters and enviroments, we study a self-excited vibratory actuator theoretically. As a two-degree-of-freedom self-excited vibratory system, the Van der Pole (VDP)-type vibration system and self-excited vibration system related to asymmetry of the stiffness matrix (ASM) with a nonlinear damping term are studied. Their characteristics are analyzed in detail using an analytical approximation method and numerical method. In the VDP-type vibrating system, one of the natural modes of vibrations of the original passive system is self-excited. In the ASM-type vibrating system, on the other hand, the original passive system is self-excited near the antiresonance fruquency in the limit cycle, so that we can utilize a vibratory motion with a large amplitude of unforced mass and small amplitude of the forced one. The methods of actuating two-degree-of-freedom passive systems as self-excited vibratory actuators and the robustness and efficiency of the actuator are also discussed.

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This paper proposes a method for designing light and rigid structures that maximizes the natural frequency of the structure for a designated mode. A design variable `density' is introduced into the finite element method and is related to the material properties of a 3-dimensional solid element. Thus a structure is expressed as a density distribution inside its occupiable domain, and the optimal structure is obtained searching for the most suitable density distribution. The proposed method makes it possible to find the optimal shape and topology simultaneously. The dynamic characteristics of the structure are improved by repeatedly modifying its density distribution.

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A seismic isolation and fuzzy vibration control system, which is comprised of a shell with springs and variable dampers between the shell and the ground, is proposed. When the shell shakes due to vertical seismic forces, the seismic isolation system is implemented and fuzzy vibration control is carried out. The damping ratios are adjusted by fuzzy theory, and stresses in the shell are reduced. The validity of seismic isolation and the fuzzy control system of the shell subjected to seismic forces is proven.

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By controlling spring stiffness, vibration isolation and reduction of the one-degree-of freedom system are achieved in this study. The control algorithm of the spring stiffness is based on the variable structure system (VSS) theory, and the theory is developed to consider the spring stiffness limitation and delay of switching time. The stiffness-variable spring is realized by a straight bar which is hinged to the mass at right angles to the direction of mass motion, and the axial force is applied at the end of the bar. The axial force causes restoring force equivalent to the spring, and the stiffness is varied by controlling the axial force. In the numerical simulations and experiments, the settling time of the impulse response and the displacement transmissibility are investigated. The results show that this system is effective in suppressing shock motion and isolating vibration transmitted from the floor.

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An active dynamic vibration absorber is fabricated to reduce the vibration of the primary system to zero at specified frequencies and to nonresonant levels at the other frequencies. Its controller is designed based on the internal model principle ; accordingly, it incorporates a model of multiple-frequency disturbance into its feedback loop. The performance of the system obtained is experimentally studied using a vibration absorber with an electromagnetic servomechanism. The experiment succeeds in removing the vibration at up to four specified frequencies.

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An improved general optimization algorithm is presented for the topology and shape optimization of a vibrating structure. This method is a generalization of the previous methods, such as the traditional OC, CONLIN, MMA and the method proposed by the authors in a previous paper. This method can be reduced to the previously mentioned methods by choosing different values for the parameters, and, in the general case, it can greatly accelerate the convergence of the optimization process through efficient calculations.

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In this paper we discuss the vibration control of a flexible structure which possesses transverse-torsional coupled vibrations using two active dynamic vibration absorbers. The H-infinity control theory is adopted to obtain an output-feedback robust controller by which structural vibrations in two lower vibration modes are reduced without spillover. The statements of the control object are organized into the generalized plant, robust stabilization and sensitivity reduction. A method of systhesis of the controller is presented in which balancing of control inputs is taken into consideration. In the numerical analysis and the control experiments, it is confirmed that the controller achieves a considerably high performance with robust stability.

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The object of this paper is the experimental consideration of the robustness improvement in the feedforward control and the control by means of the frequency-shaped cost functionals using H^∞ control theory on magnetically levitated vibration system. The vibration isolation system is a single-degree-of-freedom system and the vibration of its table, which is levitated by the repulsive force of a permanent magnet, is controlled by the attractive force of an electromagnet. Through experiments, it was verified that, by applying the H^∞ control theory, the robustness problem of the optimal control with a feedforward link can be solved. Furthermore, by adopting the frequency-shaped cost functionals, a more effective vibration isolation can be achieved over a wide frequency range.

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The demand for controls of vibration and positioning of such flexible structures as large space structures and flexible manipulators has recently increased. In these control problems, a method of synthesizing a reduced-order controller is necessary. If any couplings between the residual modes are ignored in the model reduction process and the controlled modes, dynamic spillovre occurs and affects the control performance. In this study, a new reduced-order control method for suppressing dynamic spillover by using control the modes under control is proposed and its usefulness is verified by numerical calculations.

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Recently, high speed and high precision have become very important qualities in industrial robots. High speed, however, leads to lower precision because of inertial force, interference from the axes and vibration. In particular, a large robot has low natural frequency because of its flexible joint, thus vibration control is an important problem. In this paper, in the case of the robot arm with an elastic joint, the disturbance observer which includes the elastic vibration of the robot arm and the calculated torque method are applied. First, the control rule of this disturbance observer is derived. Next, the efficiency of this disturbance observer is analyzed by the simulation of the one-link robot arm linked to a flexible joint. Lastly, this method is applied to an actual industrial robot manipulator, and high accuracy has been confirmed.

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Mechanical control can be made stable by taking into consideration mechanical resonance frequency and antiresonance frequency. A mechanical structure has different characteristics at each location at which force is applied and measuring location. The characteristics are different due to resonance frequency and antiresonance frequency. Antiresonance frequencies are determined by zero amplitude of dynamic behavior. Furthermore, their frequencies affect the control stability. This paper presents a method to distinguish between control stability and instability of the linear slider mechanism. In this method, control stability is distinguished to calculate the damping value of a multi-degree-of-freedom mechanism with control. Control algorithms are applied to positive acceleration feedback control and negative velocity feedback control.

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This paper concerns the dynamic behavior of a structure coupled with an electromagnetic field. We study the coupling behavior between vibration and eddy current using the lumped parameter model of a superconducting magnet for magnetically levitated vehicles (MAGLEV). This is a simple model with multidegrees of freedom which consists of mass, spring, resistance, inductance, and differentiation of inductance. We calculate the frequency response of vibration, eddy current, and Joule loss. These results show that the dynamic behavior of a structure in a strong magnetic field is different from the dynamic behavior without the magnetic field. For example, an antiresonance point which does not appear in the structure system appears in the coupling system. We also show the modeling method to understand the vibration behavior under the magnetic field.

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This paper deals with the two-dimensional collisions of vehicles based on the impulse-momentum relations. Usually, the impact is assumed to occur in an instant, and the movements of the vehicles during impact are ignored. In general, however, vehicles are deformed and moved each other for the duration of impact. It seems that these errors increase in some impact conditions. In this paper, it is assumed that vehicle deformations are characterized by a linear plastic body, and the impact plane and the impact point are determined from the shape of the crushed region at each time step. Collision problems considering vehicle movements during impact can be analyzed using this method. Several results of collision analysis are shown for comparison between this method and the method ignoring the vehicle movements. Finally, the vehicle velocities immediately after impact and the vehicle trajectories are discussed.

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A dynamic analysis of free-piston Vuilleumier-cycle heat pumps has been carried out by a time-stepping integration technique. This technique allows application of a nonlinear relationship between displacements and working gas pressure variations in the equations of motion for reciprocating components. Although ideal isothermal thermodynamics was assumed for the Vuilleumier cycle, the present analysis provided more accurate information on its characteristics than the linearized dynamics. Some calculations for a case study were performed, including dissipative forces with a nonlinear relationship in the equations. It was found that the present method was very effective in predicting the dynamic behavior of free-piston Vuilleumier-cycle heat pumps and in designing the components of machines.

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CDQ (cokes dry quenching system) is a waste heat recovery system that recovers waste heat from hot cokes with circulating gas and that generates high-pressure steam. In heat recovery systems, it is very important to operate the system with maximum efficiency. In CDQ, the flow rate of circulating gas must be manipulated to obtain maximum flow rate of steam. For this purpose, the dynamic model of this system is necessary. In this system, a temperature distribution within the each coke exists, because the diameter of the coke is relatively large and value of thermal conductivity is small. In this report, we investigated the dynamic characteristics of the system, taking account of the heat conduction effect within the each coke. The validity of this model is confirmed by comparing the calculated result with operation data. Next, we show that dynamic characteristics depend on three nondimensional parameters, namely, Biot number, NTU and Cr number. In the next roport, we will establish the optimum operation method using this model.

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Relationship between the structure of a tennis racket and the restitution of a ball is investigated theoretically by modal analysis and the substructure synthesis method. The racket and the ball are modeled by a beam and two masses, respectively, and they are connected by a spring. Since there is a mode of vibration which has a high value of restitution, the racket must be designed such that this mode becomes significant. For the high value of restitution, the gravity center of racket and the nodal points of modes should be close to the striking point. The natural frequency of the racket must coincide with that of the ball. The strings must be soft and the bending rigidity must be high.

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Human walking has been actively studied in such fields as biomechanics and rehabilitation engineering. Steady characteristics for a normal person walking at a constant speed are predictable based on these research results. Transient characteristics, for example, speed change in starting or stopping phase, however, have not been studied in detail due to difficulties in experimental data acquisition and processing. In this research, two large force plates are used to measure both the reaction force applied to each foot separately and their point of application in three modes of transient walking, that is, starting, stopping, and turning. The relations between the cadence and each wave peak value, which characterizes the walking motion, are shown. Experimental procedures and results will be presented. Transient characteristics to or from the steady walking state will be discussed.

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This paper deals with the changes of velocity characteristics of initiation and termination of human gait. Velocity characteristics are important in the understanding of human walking, but these have been rarely studied because of difficulties of experimental measurements. The velocity of the center of gravity of the whole body can be evaluated by integrating with respect to time the floor reaction force during walking which is experimentally obtained by a force plate. The velocity fluctuates even in a steady walking state depending on the phase of support of the body by both legs. This fact makes it difficult to discuss transient characteristics of the velocity prior to the steady state ; a model was introduced in this study to represent basic features obtained experimentally. A simple model consisting of a delay element and a first order system was used to approximate experimental velocity curves.

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In this paper, it is clarified, by theoretical analysis and computer simulation, that active attitude control of wheels yields satisfactory vehicle cornering performances during operations such as steering, acceleration and braking. The maneuverability and stability of the vehicle as a result of tire attitude control are investigated using a quasi-steady-state analysis model for the case of acting on tractive or braking force. An extended stability factor considering the characteristics of toe and camber angles of wheels is defined, which is applicable to circular turnings with lateral and longitudinal accelerations. Effects of control are analyzed by making use of this factor. Furthermore a modified control method is proposed, which makes it possible not only to improve vehicle dynamics but also to decrease actuating values of attitude angles in actual driving.

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In this paper, the sliding mode control (SMC) of the systems linear with respect to control is presented. The controller is designed to have continuous control to eliminate chattering and to provide sliding mode motion on the selected manifolds in the state space. These manifolds are selected as a linear combination of the state coordinates. Control is selected to satisfy selected Lyapunov function and stability criteria.

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This paper discusses the minimum energy control in the z-domain for a single-input, linear, time-invariant, discrete-time system. The minimum energy control in the t-domain can be obtained by the state feedback with time-varying gains, and by the open-loop form. The dynamic compensator in the z-domain is induced from the optimal input sequences and the state sequences in the t-domain. It consists of constant parameters which do not depend on the initial state of the system.

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Model reference adaptive control (MRAC) of a nonlinear uncertain plant subjected to disturbance is considered. No prior knowledge about the structure of uncertainties is assumed, nor is any constant bound on their values. The Lyapunov type of stability is analyzed. A MRAC law has been developed which provides stable tracking. The paper includes an application of the developed adaptive controller to the control of an electric vehicle which is considered to be an uncertain nonlinear system.

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This paper describes the automatic design method of a nonlinear stabilizing control system of an inverted pendulum using the genetic algorithm. The nonlinear stabilizing control system presented in this paper is a hybrid control system which is constructed of a conventional linear quadratic optimal controller and a nonlinear compensation part. The nonlinear compensation part utilizes the angle and the angular velocity of the inverted pendulum to compensate the nonlinear characteristic of the inverted pendulum. A gene consists of the coefficients of the nonlinear stabilizing control system, and a genetic algorithm with three operators ; reproduction, crossover and mutation, is used to obtain near-optimal coefficients. From the numerical simulation results, it is clarified that the sum of the control error decreases with the increasing generation, and the optimum coefficients of the nonlinear stabilizing control system can be obtained. Therefore, the usefulness of the automatic design method is verified.

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A seam position detection method is developed for a sealing robot. At the start of sealing, a six-degree-of-freedom seam position is detected by using integration of an optical profile and grayscale images. After the sealing has started, a three-degree-of-freedom seam position can be detected by using only the optical profile image. However, a deviation between the actual seam position and the desired position taught beforehand exists. In addition, the time required for image processing is considerably long compared to the sampling period in a robot control system. Thus, a holder between the vision sensor signal and the robot control signal is necessary to counteract these deviations. A control method adopting a 2nd-order holder utilizing previous signals is developed to correct the deviations of seam positions determined by image sensing and, at the same time, it corrects the deviations without time delay due to its use of forward detection by image sensing.

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An attitude control algorithm of a free-flying space robot by cooperative control of feedforward control and feedback control is proposed. The motion of the manipulator on space robot causes attitude deviation of the main body through dynamic interaction. The proposed cooperative control algorithm is composed of the Disturbed-Torque Compensation control for the thrusters, which was proposed in the 1st report, as feedforward control, and the sliding mode control for the reaction wheels, which is the known method of robust control, as feedback control. The proposed algorithm is verified by a one-degree-of-freedom model test. The robustness is also discussed.

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This paper presents measurement errors that are caused by difference of gain between sensors in the case of measuring straightness using multipe sensors, e. g., the 2-point method. In the case of the 2-point method and differential laser autocollimation, if there is a difference of gain between sensors, inclination of a measured surface causes quadratic error in the measurement results. And in the case of the 3-point method, it causes cubic error. This indicates means that accuracy of measurement depends on deviation from parallelism between the measured surface and the guide of sensors. Assuming that the spatial period of the measured surface is 30 or 50 times as long as the sampling interval, the difference of gain between sensors of the 2-point method or differential laser autocollimation must be within 1 or 2% to yield a gain error of measurement results within l0%. On the other hand, the difference between sensors of the 3-point method must be within 0.1 or 0.2%.

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In this paper, the mechanical properties of golf balls under impact loading are experimentally examined in order to clarify the mechanism of impact by a golf club. First, an air gun to fire golf balls is newly designed and manufactured in order to maintain stable conditions of collision with good repeatability. Next, the relationship between the dynamic load and deformation of balls is measured by using an originally developed load cell and a high-speed camera. Finally mechanical models consisting of a mass, spring and damper are proposed, which enable simulation of the measured load and deformation relationship. The proposed mechanical model is useful in investigating the characteristics of golf clubs while hitting balls, which is expected as a next stage.

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In this paper, we propose a real-time measuring method of a moving three dimensional object. We use a single camera image and an extended Kalman filter to track the object. Assuming that the velocity of the object is constant for a sufficiently small time interval, we construct a descrete-time extended Kalman filter on a simple motion model. The Kalman filter predicts the object position at the next sampling step from the projected position and area of the object in the current sampling image. Although we use a simple model, we can increase the estimation accuracy with an appropriate choice of the covariance matrix reflecting the effect of the system noises. We derive the discrete-time covariance matrix directly from the continuous-time model. It is pointed out that the covariance matrix usually contains additional correlation terms which cannot be ignored for a large sampling period. By simulation and experiment, we show the effectiveness of the proposed method for pendulum motion estimation.

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A simple simulation model using the finite-element method is developed to prevent slippage of transferred images in laser printers. This slippage is caused by sudden changes in paper shape due to tensile force or compressive force applied to the paper while it passes through the feeding rollers. To eliminate the tensile force, the paper must be sufficiently deflected. In addition, sufficient paper feeding force must be applied to the paper to overcome the compressive force. The simulation model is used to analyze deflection of the paper and the paper feeding force, and to design an actual paper path that prevents slippage. Experimental results using the actual system agree well with the simulated results. These techniques are applied to a laser printer that produces high-quality images free from slippage.

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This paper describes an estimation of frictional shearing stress τ_c acting on the real contact area of lubricated conditions in the upsetting of an aluminum ring. The transition of the contact ratio between a tool and a workpiece could be obtained by applying ultrasonic examination. In addition to measuring the relative expanding velocity of outer diameter of the ring as well as forging load and stroke, the varying frictional conditions could be discussed in detail. In our experiment, the results show that τ_c for lubricant of higher viscosity has a tendency to become high and τ_c decreases gradually with the progress of deformation. The value of τ_c for each viscosity corresponded well to the roughness and the topography of flattened contact area of deformed asperities. It has also been suggested that the method is very useful for estimating τ_c during a process.

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This study concerns to the determination of the path of a cutter with a smaller or larger diameter than the cam follower for milling of cylindrical cam such, as an index barrel cam, cylindrical grooved cam or end cam. There are many reasons why a full size cutter (where the diameter of the cutter is the same as that of the cam follower) is not used during processing of a cam. Errors are unavoidable when the diameter of the cutter is not same as the full-size cutter. The errors are influenced by the ratio of the diameter of cutter to that of the follower, the stroke of the follower member and the size of the cam, for example. This study shows the contribution of each of those factors to the errors and presents a guideline for the selection of the size of the cutter. Furthermore, this study shows the nature of the error depending on the longitudinal location of the cam follower.

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Transmitted torque, thrusts of driving and driven pulleys, and axial force between two pulleys were measured on a metal-pushing V-belt-type CVT. Thrust ratios between driving and driven pulleys at several different speed ratios were plotted with respect to torque ratio and compared. It was found that the relationship between thrust ratio and speed ratio was almost independent of rotational speed of the pulley and the maximum transmittable torque at a constant torque ratio. The thrust ratio is primarily a function of speed ratio. It also depends on torque ratio and coefficient of friction between blocks and a pulley. An empirical equation for pulley thrust balance was derived. The equation is expressed in an explicit form. It is so simple that it can be applicable to electronic control of CVT.

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In the first study, the change of dimensions of nylon, polyacetal and polycarbonate gears in vacuum (degree of vacuum : 10^-3 Pa) was examined. As a result, it was found that in each plastic gear, the amount of change of dimensions in vacuum was not a value which poses a practical problem. Therefore, in this succeeding study, at the same degree of vacuum as that in the first study, operating tests were carried out on five gear combinations, namely, both nylon gears, both polyacetal gears, nylon gear and polyacetal gear, nylon gear and steel gear, and polyacetal gear and steel gear, and the limiting PV-values and the wear of plastic gears in the combinations were elucidated.

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In general, regrinding of a hob causes profile error of cutting edges. The more the number of hob threads increases and the diameter of a hob decreases, the more the profile error after regrinding increases. In this paper, a new method of relief grinding for finishing a hob having a small profile error of the cutting edges after regrinding is proposed. To finish the hob with such tooth flanks, an additional motion in the direction perpendicular to the radial direction of the hob, synchronized with the conventional relieving motion between the grinding wheel and hob, is introduced. The optimum amounts of the additional motion for finishing a multiple-thread hob are shown in terms of the proportion constant for the rotational angle of the hob. To show the validity of the new method, a five-thread hob was finished on the NC tool grinder. The accuracy of the cutting edge of the hob was in the zero class of JIS for regrinding stocks of λ=0 and 5 mm.

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The finish of an automobile exterior is an important factor directly affecting a customer's purchase decision. However, while paint quality has increased in recent years, highly developed visual and tactile senses have been required in the process for painted surfaces inspection and repair, and the increasingly heavy burden on operators has become a major problem. This paper describes an automated inspection method developed at Mazda. The new method senses the distinctive reflection of convex and concave defects on painted surfaces in order to identify for repair. The corresponding system consists of a near-ultraviolet radiation emitting source with gradated radiant intensity, a video image sensor, and an image processor. Using this system, it is possible to detect defects consistently and determine whether they are convex or concave.

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In this study we propose a heuristic method for layout planning of departments with different areas, in the case where some shapes and directions of departments are not changeable. The proposed method is based on the interaction diagram which shows adjacent relationships between departments. Through numerical examples, steps of the algorithm are shows and the effectiveness of the solution for the problem that has unchangeable departments under twenty percentage of all departments is examined.

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