A series of triaxial and uniaxial compression tests of WA and GC grinding wheel materials with vitrified bonds have been carried out to confirm the theoretical analysis of their strengths and elastic moduli obtained previously. The following conclusions are obtained : (1) The grinding wheel materials with vitrified bonds are brittle materials with slant Mohr failure envelopes. (2) The stress ependency of the elastic moduli anticipated from the theoretical analysis is recognized in the experimental results. (3) As to the grinding wheel materials with vitrified bonds same in grain size, bonding strength and percentage of grain, WA is greater than GC in Young's modulus, tensile and compressive strengths.

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This study treats of the vibration with collision of the two-degrees-of-freedom system for the application to machinings or formings. The improved hammering machine due to the analytical results is designed for improvement of the dynamic properties and reduction of transmissive force and noise levels. The behavior of the model can be analysed by connection of sectional linear solutions. This paper presents basic equations that express the periodic motion, setting gap of the rigid stop and colliding velocity of the impacter, respectively.Then, provides regions of gap for the steady-state motion in the repetitive impact which have the same period as that of an excitation. The approximate equations with small damping are set up, which are useful for the practical applications. The colliding vibration properties of the system has some similarities to that of one-degree-of-freedom system : waveforms of the impacter and the exciter look like sinusoidally at primary resonances. The impact of vibration reduces at other resonances. In the frequency range under fundamental frequency, the stable region of gap becomes narrow and there are the infinite multitude of high order resonances, therefore, the frequency range isn't available for the industrial applications.

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The present paper deals with problem of safe machining operation by discussing the friction-drive function of regulating wheel in centerless grinding. The generalized equations of rotational motion of the workpiece with arbitrary cylindrical form in grinding process are derived, and the possible upper limit of grindingforce for the regulation of work speed are deduced for typical work formsfrom them. Those results are discussed from the viewpoint of the safe operation and theavailable range of set-up conditions of centerless grinding and the followings are obtained : (1) The effect of set-up conditions of grinding on the possible upper limit of grinding force for the regulation of work speed are made clear and the safe operation range of set-up conditions for typical work forms are shown. (2) For widening the safe region it is important to have the steeper work supportangle, the smaller centerheight angle and the regulating wheel with the greater frictional coefficient. (3) There exists the dangerous work form for the safe-operation, and its conditions are derived.

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In this report, it is analyzed theoretically that small diameter's female precision threading can be realized by using a new vibration tapping machine. And thisanalytical results can be confirmed by the experiments using a newly developed vibration tapping device with the electric-stepping motor. The main cutting conditions are as follows : frequency; 105 Hz (11 pulse forward-3 pulse stop-1 pulsego back-4 pulse stop) -59 Hz (22-6-1-5), the cutting length per one cycle; 0.01-0. 2 mm, cutting speed; 0. 2-0. 8 m/min, tap size ; M 1, M 2, M 3, M 4, M 5, percentage of thread overlap; 70-80%, work material; aluminum (H_B=25), brass (H_B=125), steel (H_B=168) are used. The main results are as follows : (1) The tapping torque is decreased to about 1/4-2/3 of the conventional tapping. (2) Under the conditions, tap failures scarcely occur. (3) Female thread with a precise screw thread shape can be machined. (4) By this study, it is proved that this new tapping machine has the possibility of precision machining in small diameter's female screw threading.

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In order to clarify the tightening properties of threaded joints used in ultrasonic vibration system, effects of form accuracy of bearing surfaces on tightening quality of the joints under ultrasonic vibration in the axial direction are investigated. As the results, it is found that the form accuracy of bearing surface influences the tightening quality of threaded joints under ultrasonic vibration. (1) Concerning form accuracy of bearing surface, the tightening quality is affected by the form of bearing surface as well as the inclination of it to the axis of screw thread. In the case that the form is slightly concave and tightening force is large, critical amplitude A_l at separation between bearing surfaces is large, which means the joint has high tightening quality. (2) Concerning relative inclination in combining bearing surfaces, it is affected by the inclination which is caused by the clearance between both threads. In the case that the relative inclination is the same degree as that by the clearance or smaller than that, the value of A_l depends greatly on tightening force and it increases with an increase of tightening force.

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It is one of important problems for the strength design of bolted joints to know the deformations of the bolt-head, the nut and the clamped parts. This paper treats the analysis of deformation in the case where a cylindrical plate is fastened by a set of bolt and nut. Firstly a method to analyze the bolted joint as a contact problem among three elastic bodies by finite element method is proposed, and the deformation in the various parts of the bolted joint is analyzed by this method. Secondly, he deformation of the bolted joint including that of the nut are measured by holographic interferometry and compared with calculated ones. The main conclusions are as follows : (1) Though the calculated values for the axial displacement of the nut top face and of the bolt top face are smaller than the experimental ones, the shape of their distributions, and the calculated values for the axial displacement at the top face of the clamped part show a good agreement with the experimental results. (2) It is confirmed that the influence of the relative pitch difference between the bolt and the nut on the axial displacement at the nut top face is significant.

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The dynamic dividing error between two shafts rotating at a given velocity ratiois measured by a newly developed apparatus where two pulse signals are input from the rotary-encorders attached to the respective shafts. In an experimental usewith a middle size (420 mm worktable diameter) gear hobbing machine, the dynamicdividing error has been measured and recorded not only during the idle running but also during machining. By transformng the recorded analogue signal with an FFT (fast Fourier transform) analyzer and by consulting to the design drawing of the rotary transmission mechanism, specific parts in the mechanism have been identified that cause the dividing error. Also by applying the Fourier transform to the profile error of the gear teeth generated by the hobbing machine, the tooth profile error components have been identified that are attributable to the dynamic dividing error caused by the transmission mechanism. The proposed experimental procedures may be effectively applied at the hobbing machine manufacturers forchecking their product, and at the manufacturers of tooth gears employing many hobbing machines, for examining and maintaining the generating accuracy of their production equipments.

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A procedure for the numerical calculation of electron beam drilling in metals isdescribed. This procedure is based on appropriate zoning of the region to be drilled and the assumption that as metal is melted it is forced out of the hole by forces exerted by vaporizing metal. Calculations of drilling in several metals are carried out for different pulse durations (t), beam currents (I_b), and number of pulses (N), for a constant acceleration voltage (V) of 100 kV. Data were obtained for mild steel, copper, aluminum and molybdenum under the following conditions : V=100 kV, I_b= 3OmA, and t=0. 1, 0. 2, 0. 5, 1. 0 ms. The depths, diameters, and shapes ofthe drilled holes predicted by the proposed procedure are in close agreement with experimental results. During drilling by multiple pulses there is normally a fixed time interval between pulses. As a result of heat diffusion during this time, molten metal removal does not begin immediately at the start of the next pulse. The lag time, defined as the time required to initiate molten metal removal from the hole at the beginning of each pulse, is predicted by the proposed method. When a hole is drilled by multiple pulses, the lag time increases as the hole becomes deeper.

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The surface finishing characteristics in the extrude hone process are empirically known to be associated with the property of media which is composed of the grits mixed into the flowable viscoelastic material. The visco-elastic property of the media that is very important to evaluate the finishing characteristics, however, has not known. The present paper describes a newly designed viscoelastic measuring system which is used to determine the properties of the media at different temperatures. The finishing mechanisms in the extrude hone process are discussed on the basis of the property of media. The visco-elastic measurements of the media have proved that its property could be expressed in four-element model. The finishing experiments conducted on the steel and non-ferrous metal have shown that the media of higher elasticity and lower viscosity yields a considerable high removal rate.

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This report shows that the bursting speed of rotating wheel fluctuates by several percents according to the intensity of clamping pressure, through theoretical analysis and experiments. From the discussion on results of the preliminary experiments measuring the stress distribution in the wheel, a model is presented, in which the frictional force μp acting on flange-wheel interface due to clamping force resists the radial displacement caused by centrifugal force, and the stress solution is derived from the two-dimensional elastic theory. This solution lies between the stress values on surface and central plane of wheel getting from the three-dimensional analysis by the finite element method, and is fairly applicable as an approximate one to a thin wheel whose thickness is under 20% of the outer radius. The non-dimensional maximum value of circumferential stress σ_θ working on the arbor hole edge, which acts as a trigger for wheel bursting, reduces with the increase of the parameter μp/ρω²γ_o² (ω; angular velocity, γ_o; outer radius, ρ; density) from the value of free-sustained hollow disc often referred to compare with the experimental values. Then, the stress resulting from ring-like axial pressure p does not exert a powerfull effect on the σ_θ distribution in rotating wheel. In the wheel bursting experiment under two levels of the clamping pressure, there is brought the difference of 7% in bursting speed.

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An optical technique based on the optical Fourier transform with lens system is developed to estimate quantitatively the characteristics of the working surface of grinding wheel. The grinding wheel surface is illuminated by parallel laser light and the light reflected on the wheel surface produces a power spectrum pattern on a plate located at the principal focus of Fourier transform lens. The characteristics of the grinding wheel surface can be estimated by this power spectrum pattern. From the measurements of power spectrum patterns of the grinding wheel surfaces, the results obtained are as follows : (1) The proposed measuring method can estimate the characteristics of the working surface of grinding wheel rotating at 3000 rev/min. (2) From the wavelength u₀ where the average power spectrum falls to 4% of its maximum intensity, the average width of grain wear flats around the grinding wheel surface can be estimated quantitatively. (3) From the wavelength u₀, the critical grinding time, namely, the life time of the grinding wheel can also be determined. (4) This method will be able to be applied to the real-time measurement of the characteristics of the grinding wheel surface.

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In this report, functions of the muscle systems in the leg are discussed on the basis of the experimental results. Here it is shown that the muscle system during the walking motion functions fundamentally as a spring and the functions of a motor and of a damper are added to control the spring action and to smooth the motion. Further a mechanical system consisting of a spring, a motor and a damper is trially designed to be applied for the hip, knee and ankle joints (combination of a spring and a motor at the hip joint and at the ankle and that of a springand a damper at the knee). And it is shown by the analytical results that the motion produced by the fitting control of the mechanical system can become close to the normal walk-ing motion.

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By a statistical approach COFG test is investigated theoretically and experimentally on the assumption that grain cutting edges distribute randomly in the three dimensional space. Results are summarized as follows : (1) The number of effective cutting edges obtained from COFG test is not the number of grain cutting edges which have effective concern with the cutting of work, but the number of grain cutting edges which have effective concern with the generation of finished surface, although the difference is little as compared with that in case of conventional grinding. (2) Rate of effective cutting edges varies with grinding conditions, then the characteristic obtained from COFG test which is carried out under a specific grinding condition cannot be directly applied to that in case of conventional grinding. (3) When the measurement of three dimensional grain cutting edge density is intended, cluster circumferential length must be taken into account. Moreover cluster infeed must be taken into account when the number of grain cutting edges projected on the wheel outermost surface is intended to be measured.

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The cutting mechanisms of the self-propelled rotary cutting tool are equivalent to these of the tool with restricted tool-chip contact length in orthogonal cutting. Based on this result, the analytical predictions of the chip formation and cutting forces are carried out by use of the orthogonal cutting data. And, a thermal model that a finite cylinder rotates and the heat flows into the cylindrical body from a part of its end face is used in the theoretical analysis of the cutting temperature. These calculated values are good consistent with the experimental results. The chip formation of the rotary cutting tool is only determined by the relationship between the cutting ratio and the toolchip contact length without regard to the equilibrium of forces. The low cutting temperature is caused by the fact that the heat source area decreases with the tool-chip contact length and that the heat transfer rate and the heat source velocity increase with the tool revolution.

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The process how the surface shapes of optical glass and polisher change in pitch-polishing is presently studied by treating their surfaces as those of the second order of revolution. Experiments were carried out in two cases; one was for crude polisher by optical glass, the other for another optical glass by the polisher polished so. The results show that the process under the right polishing conditions has almost the same fundamental characteristics, common to both cases, asthose found in lapping, being analogeous to that in reciprocation lapping whichwas performed by combining different kinds of workpieces as lower and upper ones.

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