Response during a uniform acceleration through resonance of the non-linear systems with a hardening spring is analyzed by using the asymptotic method. The equations to estimate the characteristic points in the response, which are the maximum amplitude point and the frequency jumping point, are derived by the analysis. The more simple approximate formula is obtained to estimate the maximum amplitude value. The estimated value showed good agreement with that obtained by a numerical integration under a certain condition.

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An analysis is presented for the free vibration of a cantilever annular sector plate with curved edges. For this purpose, the plate is transformed into a regular sector plate with unit outer radius by a transformation of variables. The transverse deflection of the transformed plate is expressed in a power series, the dynamical energies of the plate are evaluated, and the frequency equation is derived by the Ritz method. This method is applied to annular sector plates with symmetrically or unsymmetrically curved radial edges, and the natural frequencies and the mode shapes are calculated numerically up to higher modes. The eigenvalues obtained here are compared with experimental values of other investigators.

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New epicyclic gears in which in internal gear is elastically supported by rubber bushed are designed and manufactured in order to shorten the length of reduction gears in a marine propulsion shafting system. Then, torques on the output shaft of a diesel engine and the input shafts on both the epicyclic gears and a hydraulic dynamometer as well as fillet stresses on the internal gear teeth are measured on a test bench similar to the marine propulsion shafting system. Consequently the following is revealed : Effects of elastically supporting the internal gear on reduction of both the dynamic tooth load and the torques of the input shafts are large in the low and middle engine speed ranges especially.

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It is recognized nowadays that flexural and torsional vibrations couple together in a gear train system from this point of view though they have some difficulties in practical use. Among many general analytical methods of vibration system, the structural dynamics modification method seems to be appropriate to apply to a gear train system as it is possible to use known modal parameters of each shafts. One of the problems of this method in the application to a gear train system is how to appropriately deal the mesh of the gear teeth in the analysis since the practical utility of this method greatly depends on it. Here, in this paper, a practical analytic method of a complicated gear train system is presented and some new vibrational properties of a gear train system is clarified through it.

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This paper deals with the self-excited vibrations of a rotating Mindlin circular plate subjected to a concentrated frictional force as a function of relative slip velocity exerted on its outer circumference. It turns out from the averaging method and a direct numerical integral method that only single modes are stable, the generating modes are fixed in space even if the circular plate rotates and the resulting modes deviate from those generated in a stationary circular plate in the rotating direction due to rotation. Furthermore, the self-excited vibration becomes unstable or the steady-state solutions cease to exist, as the rotating speed is increased. The analytical results are confirmed by the experiment.

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A truncated conical rotor undergoes unstable vibration when it is partially immersed in water and driven at a supercritical speed. The unstable vibration is a forward whirl and occurs at a limited range of rotation speed and rotor immersion in water. A vibration suppression ring having 4 or 8 radial fins is installed concentrically to the truncated conical rotor, to investigate experimentally the performance of vibration suppression for a variety of combinations of the gap between the rotor and radial fins and the degree of radial fin submersion in water. Experiments show that a ring having 4 radial fins installed parallel to the diagonal of a rectangular water tank is most effective for vibration suppression when the gap is almost equal to half the rotor diameter and the fin submersion equals the rotor's immersion in water. We achieved vibration suppression to one tenth of that obtained for cases where no ring was used.

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This paper presents experimental studies of pressure fluctuations in a cavitating pipe-flow. Using a high speed cinecamera, the behavior of the cavity which grows and collapses after the throat of a sharp-edged venturi was photographed and analysed. The cavity is periodically cut off at the throat, swept down and collapsed rapidly at a certain distance from the throat. After the collapse the fluid around the cavity is accelerated and pressure waves are generated, which then excite the fluid column into oscillation. The cavity shedding frequency becomes lower (less than 100 Hz) with increase in the average cavity length and resonance phenomena occur when it coincides with one of the natural frequencies of the fluid column.

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The steady self-excited vibrations of a bowed string with both ends fixed, subject to air resistance as the only positive damping are investigated. Contrary to the forefoing report, where vibrations at the Helmholtz point are discussed, here we take up vibrations at neighbouring points to the Helmholtz point. As a result, Schelleng's "rabbit ears", namely sharp spikes of bow force at the start and at the end of the stick interval are theoretically deduced.

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A microstepping method, in which a sinusoidally varying current is supplied to each filed coil with a different phase to shift a stagnation point with a smaller step relative to a full step, has an advantage over conventional stepping process. By this control technique an elimination of vibration and a realization of higher resolution are expected. However in reality, due to a distorsion of driving torque distribution, the microstepping angle is not uniform and a troublesome try and cut procedure is necessary in individual application. In this paper the microstepping behavior is treated by the Spanworm equation, and the possibility of an analytical designing procedure for this microstepping system is shown.

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To attain optimum design of vibration cotrollers to suppress many resonance peaks of machine structures, it is necessary to know the equivalent mass at the mounting location of the controller. This paper shows two ways for estimating the equivalent mass : one is the modal analysis method, and the other is called the mass responsive method, which utilizes the variation of the natural frequency of the structure when an additional mass is attached. The first method mentioned is useful to identify modal mass having "physical meaning", while the other method is most suitable for application in the experimental analysis. The accuracy of these methods are compared with each other by applying them to three kinds of mechanical structure.

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In order to calculate the pressure pulsations in pipelines in the frequency domain, it is necessary to linearize the nonlinear damping elements, under conditions where the flow is periodic in time, but not sinusoidal. The authors have previously proposed an idea for the equivalent linearization in such cases, namely that two coefficients should be determined, one for the steady flow and the other for the fluctuating flow. In this paper, the response for the pressure pulsations of a ladder circuit is calculated, by applying several flow inputs, and by using the equivalent to the difference equations to describe the relations of flow and pressure in a pipe element. The obtained results are all in good agreement with those obtained by the Runge-Kutta-Gill method. So the linearization obtained by suing this idea is useful for calculating the pressure pulsations.

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A drilling method using low frequency vibration and some experimental results for ceramic materials have been discussed in this paper. In the drilling machine, the vibration due to a collision generated by a coil spring and an electromagnetic clutch is applied to the rotation tool and the tool drills a soda glass as a workpiece in the slurry supplied on the machining surface. As a result, it is evident that the machining efficiency is increased by means of enlarging the position of the collision, and by increasing the rotational number of the tool and the frequency when the amplitude is constant.

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Static tests were carried out for rubber bearings of 490 kN rated load which comprised 30 natural rubber sheets of 5 mm thickness 440 mm diameter bonded to steel plates. The tests showed that the bearings had stiffinesses to provide a 50000 kg rated mass with a horizontal natural frequency of about 0.5 Hz and a vertical one of about 17 Hz and that they could accept a displacement of about 300 mm under even a vertical load of 4 times the rated load. The tests also revealed characteristics of the horizontal restoring forces under various constant vertical loads and the vertical restoring forces under various fixed horizontal displacements. The horizontal stiffness of the bearing decreased with increased vertical load ; under a fixed vertical load, it was roughly linear for displacement. The vertical stiffness considerable decreased with horizontal displacement. These characteristics of the horizontal and the vertical stiffnesses were analyzed using simple models and fairly good results were obtained.

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Rubber bearings of 980 kN rated load were tested to investigate the characteristics of restoring forces of full scale bearings for earthquake isolation of buildings. These bearings comprising 27 natural rubber sheets of 6 mm thickness and 600 mm diameter bonded to steel plates were designed to provide a 100000 kg rated mass with a horizontal natural frequency of 0.51 Hz and a vertical one of 21 Hz and to accept a horizontal displacement larger than 300 mm. The static tests were carried out with satisfactory results. It was confirmed that the performance of the bearing met the specifications well. Furthermore, the vertical load distributions across the top plane of the bearing under various horizontal displacements were measured, and showed that they were always concentrated in the overlapping area of the top and bottom planes. This verified that the rubber bearing substantially supported the vertical load by the overlapping area.

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The rolling noise arises from the interaction of the vibration characteristics between a rail and wheels through the contact points. This paper deals with the coupled vertical vibrations between a rail and wheels, regarding the rail as an infinitely long Timoshenko beam installed on an elastic foundation and the wheels as point masses. The authors analyse the linear and the nonlinear vibration s due to the linear and the nonlinear Hertzian elastic contact forces between the rail and the wheels respectively for the case that two wheels move along the rail with a sinusoidal irregularity, and examine especially the influences of the vibrations of the rail between wheels upon the coupled vibration characteristics. The random vibrations due to the irregularity of the rail are also discussed.

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A method for the prediction of the propagation of ground vibration from a railway train is investigated. It is assumed that the rail and sleeper are one body. In the case of a joined rail with splice plates, the rail is excited by shocks from wheels passing over the rail joints. In the case of a joined rail by welding, the rail is excited by shocks from wheels passing through predetermined points on the rail. In both cases, it is considered that the vibrations generated at the rail are damped free vibrations and the input to the ballast is given by the power spectrum density of the pulse train led by the envelope function of that vibration. The ballast, roadbed and ground are treated as a concentrated constant systems. This method is applied to a level track, and prediction values are compared with measured ones.

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This report presents some illustrations on practical use of the car-vibration analyzing system developed for the maintenance of riding quality. This analyzing system was applied experimentally to the long-term endurance test of Shinkansen test of Shinkansen electric cars at the speed of 240 km/h. As a result, it was confirmed that this system was available for practical sue both in research work and maintenance. Further, the following matters were made clear. (1) Riding quality level L_T on the Tohoku Shinkansen at 240 km/h speeds is evaluated to be in the range of "Good". (2) The riding quality of each car of a train varies by the coupled position in the train. (3) The L_T of vertical vibration does not increase with the extension of running distance. (4) The L_T of lateral vibration increase 2∼3 dB in the running distance of 300000 km until truck overhauling.

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Prediction of the dynamic behaviour of the marine diesel engine is an important theme from the standpoint of ship design. Previous prediction methods, however, are based on an engineer's empirical results or experiences and, for that reason, are not always suited to analysing the new or different types of engines. in this paper, a component mode synthesis method is proposed to predict the dynamic response of the marine diesel engines. The purpose of this method is to solve the eigenvalue problems of large order structural systems in short computer run times. With this advantage, it is possible to develop a more realistic analytical model in accordance with the engine drawing and, therefore, to predict accurately the dynamic response of the marine diesel engine without and, therefore, to predict accurately the dynamic response of the marine diesel engine without experience or know-how. Two examples -- the marine slow -speed diesel engine and its 1/7-scale acrylite model-- are presented as the application of the component mode synthesis. They are shown to be in good agreement with experimental results obtained b the exciter tests.

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In this report, the forced vibrations of a rectangular plate subjected to electromagnetic force by an electromagnet are investigated theoretically by the finite element method, and the numerical results are compared with the experimental ones. The rectangular plate is fixed along one edge and free along the other three, and twelve rectangular elements are used in the finite element analysis. The electromagnetic force character is supposed to be uniformly proportional to the square of the exciting current of the electromagnet in each rectangular element according to the measured data about the magnetic flux density. The numerical results agree well with the experimental ones except for nonlinear vibration behaviors. Then, it is observed experimentally the the second order superharmonic and the one-second order subharmonic vibration s due to the nonlinearity of the electromagnetic force.

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This paper considers the control of a pendulum under torque limitation ; especially, the torque control is studied such that a pendulum moves to the upright position with zero-velocity. First, an energy equation governing the motion of a pendulum is derived. Second, the trajectory of the pendulum is considerd by the use of an energy diagram ; some schemes of torque control are examined and calculated. Third, these numerical results are compared with those of experiments.

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A new method of designing a digital controller is proposed in this paper. We consider the design problem that the closed-loop system with a cascade compensator approximates the reference model endowed with desirable characteristics. A integrated square error criterion is introduced as a measure of the approximation. Minimizing the criterion, a linear equation is obtained for unknown parameters of the reduced-order controller. The method is not based on the approximation of the high-order controller which realizes exactly the specified reference model, but on the approximation of the open-loop transfer function. Strong points of the method are that the order of the controller can be arbitrarily specified and that the order of the plant model is not required as a priori knowledge. A example is given to illustrate the effectiveness of this design method.

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The trial production and the inspection test of a three-dimensional standard gauge equipment are carried out. Two types of equipment are designed for the calibration test of the three-coordinate measuring machine(3CMM). Each equipment is fabricated from precision steel balls arranged on a base plate- (1) 20 pieces of ball are placed in a rectangular lattice shape on nearly the same plane - (2) 3 of 9 pieces are spaced on three different heights. The measuring probe is positioned on the balls and the center coordinates are measured to determine the three-dimensional relation of each ball position. The inspection test of the standard gauges are performed with the 3CMM whose discrete distribution of the error vector is already known. The repeatability and the reproducibility are observed in the test. As a result, the standard gauge equipment built as a trial proved to be adequate for practical use in the calibration test of other 3CMM.

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This paper aims to develop a practical method for making a wider range measurement of straightness, with good accuracy, possible, even thogh using a handy apparatus. An analysis based on the least square method is presented about the data coupling method employed, and basic matters concerning data treatments, error variances in measurement and the improvement of measuring accuracy are considered. A simple experimental apparatus aided by a personal computer is provided for actual measurements. Experiments bring about good results in the sense that the measuring operation based on the overlap coupling of data can be successfully made, and that measured values seem to have fairly good accuracy. Consequently, it is shown that the method employed has practical usefulness.

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Sound generates when compressed air is blown onto the open-ended face of a small pipe. The sound frequency varies with the displacement of a solid placed close to another open-ended face of the pipe. This paper deals with the theoretical analysis of the sound frequency generated on the pipe. A theoretical investigation considers air jet behavior on the open-ended face, and the sound impedances both inside and outside of the pipe. The results of sample calculations for the theoretical frequency equation and the experiments coincide significantly for cases of large displacement ; however differences between both results are observed for cases of smaller displacement.

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In this paper, a new type of double-row admission gas journal bearing with circular slot restrictors is proposed and the static characteristics are investigated. The gap of the slot region of this bearing can be made only be supplying pressure into the bearing because the bearing part corresponding to the slot region is elastically deformed. This bearing, therefore, does not need a shim prepared corresponding to the gap of the slot region. Furthermore, this bearing can possess easily the maximum load capacity in a very small bearing clearance of less than 10μm, since a very narrow gap of the slot region is easily obtained by varying the thickness of the elastically deformed part. The experimental results are in good agreement with the theoretical results obtained by the analysis for the conventional double-raw admission gas journal bearing with circular slot restrictors.

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The dynamic characteristics of cylindrical journal bearing with an axial oil supply groove are numerically analyzed by taking the film rupture and the reformation boundaries into consideration. The results, based on the assumptions of frozen cavity, constant cavity pressure, constant gas volume in the cavity and adiabatic charge of the gas are compared to each other. It is found that the oil film coefficients depend on the movement of the cavity boundary and the fluctuation of the cavity pressure. Adiabatic change is the most appropriate assumption if the gas is conserved in the cavity. However, the dynamic properties of a heavily loaded bearing can reasonably be estimated by constant pressure assumption. On the other hand, those of a lightly loaded bearing by constant volume assumption.

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To reduce machining time and to increase machining accuracy, high speed cutting has attracted special interest recently. A key aspect of this machining process is the development of high speed main spindles of machine tools. In this study, the basic performance of a spindle supported with ball bearings is investigated. Oil-air lubrication which seems to be most effective to increase the rotational speed is applied. From the experiment, some useful information for developing very high speed spindle systems is obtained.

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To investigate the lubrication condition in knee prostheses under walking conditions, a knee joints simulator is used to simulate the tibial axis load and flexion-extension motion. The fluid film formation in knee prosthesis models is evaluated by measuring the contact electric resistance between a femoral stainless steel component and a tibial conductive elastomeric or polymeric component under constant applied voltage in a knee joint simulator. The effect of swinging motion and the variation of load on the fluid film formation is examined. It is shown that the fluid film formation in a knee joint with an elastomeric tibial component changes, depending on the walking phase, and the film thickness becomes minimum just prior to the toe off during walking motion.

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Using a two-disk machine, the process leading up to the occurrence of scoring on carburized rollers having four different surface roughnesses was investigated in detail, under four different conditions of asperity interaction brought about by two combinations of the direction of lay of high-speed-roller/low-speed-roller (circumferential/circumferential or axial/axial) and two drive ratios of the rollers (integral 2 or hunting 1.95). The state of oil film-formation, which was related to the film parameter, was better in pairs of rollers with axial lay than in pairs or rollers with circumferential lay. For smaller initial surface roughness, the coefficient of friction and the surface temperature are also smaller. The effect of surface roughness on the scoring limits could be predicted from these tribological features. But in the case of the hunting drive ratio, the experimental results on the scoring limits were scattered. This can be attributed to the variations in the local severities of asperity contacts at each revolution. And in the cases where the surface roughness was very small the scoring limits did not increase so much because of local concentrations of contact stresses at the side ends of the roller.

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Nitrided aluminium chromium molybdenum steel gears were fatigue-tested using a power circulating gear testing machine. The effect of hardened depth on the load carrying capacity and failure mode of the nitrided gears and the relation between tooth profile change and dynamic performance in the fatigue process were experimentally elucidated. Three failure modes were recognized in these experiments ; one was tooth breakage due to bending fatigue at the tooth fillet, and the others were spalling on the tooth surface and tooth breakage due to spalling near the pitch point. Fatigue strength of the nitrided gears tended to increase with the increase of hardened depth. The changes of tooth root strain, noise and vibration profiles during the fatigue process were slight, since the change of tooth profile deterioration was insignificant.

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A resonance type gear fatigue tester has been developed to evaluate tooth root fatigue strengths rapidly and efficiently. The tester operates on the resonance condition. One of a pair of test gears is held stationary to the tester bed and the other, fastened to the vibratory shaft, is oscillated against the stationary gear. The torsional vibration of the vibratory shaft is excited by the rotating eccentric on the end of the lever arm fixed to the shaft. Torque amplitude is controlled by varying the rotational speed of the eccentric, which is rotated with a 1.5 kW induction motor driven by a frequency converter. If the test frequency is slightly below the natural frequency of the vibrating system containing the test gears, sudden overloading occurs with the natural frequency drop due to slip on the tooth face and so on. To prevent overloading, a tester is designed so that the frequency can be set above the natural frequency. The test frequency range of the tester is 1000-3000 cpm and the torque capacity is 1200 N·m.

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An investigation of sound generated form a two-step reduction gearbox was carried out in order to obtain basic information for the reduction of sound and the abnormality diagnostics for gearboxes. Test gears having an accuracy of Class JIS 1, tooth profile error, and pitch error were prepared. Three kinds of tooth profile errors, particularly depression at the pitch point, and projection or recession at the addendum flank, were formed on the test gear teeth. The gearbox was driven with and without load, and the sound generated was picked up by a condenser microphone. Using the signal thus obtained, sound waveform observation, sound pressure level measurement, and real time frequency analysis etc. were carried out. From the experimental results and considerations, the fundamental characteristics of the sound of a gearbox having an erroneous gear were clarified, and some basic information on abnormality diagnostics for gearboxes was obtained.

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The sealing performance of rarefied-gas viscoseals with triangular spiral grooves is studied experimentally in order to confirm the theory previously developed by the authors of this paper, and a few experiments on the performance of the case where a net flow by pumping action exists are also performed. For the estimation of the sealing performance of seals with a net flow, the definition of the sealing coefficient which is used for seals with not net flow is expanded. The experimental results agree well with the theoretical predictions in the pressure ranges where a slip flow holds, and the expanded sealing coefficient successfully compares with the sealing performance of seals with a net flow.

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In desiging of bolted joints with gaskets, contact stresses and the compressive spring constant K_cg for clamped parts with a gasket have been estimated using a model in which laminated hollow cylinders are fastened by a single set of a bolt and a nut. But, most practical bolted joints with gaskets are fastened by multiple bolts. Therefore, it is of practical importance to examine the effects of multiple fastenings on the contact stresses and the compressive spring constant K_cg. In the present paper, a model in which clamped parts with a gasket are fastened by multiple bolts is proposed and an analysis is done. By comparing the analytical results with the results obtained from a single fastening model, the effects of multiple fastenings on the contact stresses and the value of K_cg are made clear by numerical computations. In addition, an engineering calculation method of K_cg is proposed.

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A conical headed punch is forced through the hole in sheet metal to form lip flanges, which is subsequently used for eyelet tab staking of the lap joints. The object of the present investigation is to provide reasonable answers to the crushing strength of the lap joint. The summary of the result is ; (1) Crushing invariable occurs at the blanked-part of the sheet during stretching of the joints. But, in this state, work hardening at the compressed region is affected by dimension and size of something. (2) Lip flanges restrained in the change of the internal shape of eyelets under the staking operation, and subsequently, the strength of the joint is increased considerably. (3) From the viewpoint of joint efficiency, it is seen that it cannot endure great loads nor great stressed.

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A pyramidal headed punch is pushed through sheet metal to form petal flanges, which are subsequently used for eyelet tab staking of the lap joints. The present report announces the sequel to the report which appeared in the previous publication. The crushing strength of the joint is mostly determined in a similar way of thinking at lip flanges. But petal flanges seem to have less crushing strength compared with lip flanges. Such results are wholly attributed to the fixed position of petals due to the force form outside, and/or the change in the internal edge shape of the eyelet under the staking. From the viewpoint of joint efficiency, it is one of easiest methods for permanently assembling light parts.

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This paper describes a new finishing process (magnetic abrasive finishing process) in which a free from surface is finished in magnetic field using magnetic abrasives of 80 μm in mean diameter composed of both iron and alumina particles. From the experimental results, it is found that the spherical surfaces (convex surface and concave surface) of ferro-magnetic substance are finished very easily in a short time and its machining accuracy is high. On the other hand, the finishing performance in the case of non-ferro-magnetic substances is restricted due to the work thickness. Next, the finishing possibility for a free form surface is confirmed by modelled experiments in which plane and cylindrical surfaces are machined by applying a NC controlled machine tool.

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Advanced ceramics have some excellent properities as the material for the mechanical components. It is, however, very difficult to grind ceramics with high efficiency because of their high strength, hardness and brittleness. In this paper, experiments are carried out to obtain the basic knowledge of ceramics grinding with high efficiency. Representative advanced ceramics, such as Al₂O₃, ZrO₂, SiC and Si₃N₄ are grond with diamond wheels. Special attention is paid to comparison between the conventional and creep feed grinding of ceramics. Results obtained in this study provide some useful informations to attain the high efficiency grinding of advanced ceramics.

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In the plunge grinding process. there are many non-linear characteristic parameters. The effects of the parameters which include cutting stiffness, and contact stiffness are so complicated that the grinding conditions are not sufficiently clear. Therefore the usual study assumes that the grinding process is a linear system. This paper studies the quantitative relation between normal grinding force and its parameters to describe the form of an exponential function both theoretically and experimentally. As a result of the investigation, the in-feed process of the grinding is determined by the maximum normal grinding force, cutting stiffness, and contact stiffness. The cutting stiffness and the contact stiffness can be expressed in the form of exponential functions of real cutting depth or normal grinding force. These exponents of the functions are constant for the grinding conditions. But, contact stiffness is changed by the dressing speed. A close agreement between theoretical variations and experimental results was obtained.

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Various methods exist for determining the qualitative and quantatiye integrity of a diamond-turned surface. Particularly, the micro-roughness and residual stress of surfaces are used for preliminary evaluation of surface integrity. That is to say, the availability of reflectors, capacity of disc-memory and other capabilities of diamond-turned surfaces are dependent on the surface integrity. The amount of micro-roughness and residual stress depend on the conditions of the machining process, in this case, on the single crystal diamond turning conditions. Especially, the residual stress are affected by the manufacturing (heat treatment and each machinig) of Al alloys. From these points, the paper describes the phenomena of micro-roughness and residual stress of the surface region caused by various machining coditions.

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The slider's three-dimensional displacements due to the contact deformation at sliding joints are analyzed. The sliding joints are represented by non-linear spring elements which are distributed evenly on the sliding face, and the kinematic model of a slider including the sliding contacts is introduced. By using this model, the slider's three-dimensional displacements caused by any external force can be analyzed. It is shown that the analysis can well explain the experimental results which were made through the model of an existing machining center's table. Secondly, the analyzed slider's displacements are converted to the machining error components, and the effect of contact deformation is evaluated. The component which affects most the machining accuracy is regarded, and the corresponding slideway is redesigned to increase its contact stiffness. By repeating this process, the optimal slideway specification can be decided.

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Mixtures of ferrous metal powders and non-metal additives are sintered and the sintered materials are cut. Then, the progress of tool wear during cutting is examined, and the most effective additives for prolonging tool lift are found. The conclusions obtained in the experiment are as follows : (1) The most effective additives are glass, talc and boron nitride. (2) By the addition of a 3% glass to the ferrous material, tool life has been increased by an about factor of sixty. (3) By the addition of a glass and talc mixture to the ferrous material, tool life is prolonged still more.

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Mixtures of stainless steel powders and non-metal additives were sintered and those materials were cut, then, the progress of tool wear in cutting were examined. The most effective additives to prolong tool life were found. The conclusions obtained in the experiment are as follows. (1) The most effective additive was boron nitride. (2) The addition of a few volume percent of boron nitride to stainless steel made the tool life a hundred times longer than in stainless steel without additives. (3) By addition of a boron nitride and glass mixture to stainless steel, tool life was prolonged still more.

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Resin concrete has been used in machine tool structures tool structures in order to improve the dynamic properties and to reduce the lead time of producing. It has been, however, pointed out by MTIRA that the composite structure made of steel combined with resin concrete is inferior to the structure made of conventional materials in the thermal deformation. In this paper, the thermal deformation of a structure consisting of steel and resin concrete has been experimentally investigated using a simple model. It is concluded from the results that large thermal expansion and low thermal conductivity of resin concrete compared with steel or cast iron induce the large thermal deformation if the application of resin concrete is not suitable. In addition, some useful applications of resin concrete to the machine tool structures are proposed ; prevention of thermal deformation due to room temperature change, improvement of cooling efficiency, etc...

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Described is the soft ware system for the diagnosis of the cutting status in machining and its adaptive control. For the diagnosis of the cutting status, the concept of "information vectors" is introduced, which form a partially-ordered space for pattern recognition. The fuzzy set theory is also employed for the data handling and the control of the cutting status. Instructions from the human boss as his skill in machining are accepted on the CRT by writing them as fuzzy control rules with the fuzzy information of the concrete values required in describing them.

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