Increase of cutting speed will be one of the most easily applicable means to perform a high productive honing. In this report, effects of increased cutting speed in steel honing are investigated on finishing performances and residual stress on finishing surface. Work material used is the 0.45% plain carbon steel bars heat-treated into three grades of hardness. When high cutting speed of 150 m/min, almost the same finishing performances includng shape accuracy can be obtained as in usual speed, but the stick behaves harder in keeping with increase of critical pressure and decrease of stick wear. However, over a limited range of middle cutting speed, finishing performances deteriorate extremely and its state comes worse with decrease of hardness of work material. This deterioration may be attributable to the welding of chip. And, the X-ray diffraction analysis on finishing surface layer shows there exists a compressive residual stress caused by dominant burnishing of cutting grains and its magnitude is little influenced by increased cutting speed and depends on the cutting direction of grains.

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Lapping parameters in a rotation/reciprocation lapping are studied about their influences on the surface generation process of upper and lower workpieces, treating the surfaces as those of the second order and the fourth order of revolution. Relations are obtained between the parameters and characteristic constants used in a linear vector differential equation which describes the process. Simulated and experimental results show that (1) the process is hastened at proper stroke of the reciprocation and eccentric distance from the reciprocation trajectory of the upper workpiece to the center of the lower one, (2) the deviation from the tendency for the upper and lower workpieces to fit each other is affected by the parameters in (1), the distance between a supporting point of the upper workpiece and a lapping surface and the frequency to supply newly abrasives, and (3) there exist some lapping conditions not to cause undulate surfaces.

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Reactive sputter etching characteristics of Si wafer have been studied, in order to introduce the reactive sputter etching to a final Si wafer process in stead of the conventional wet method. The results obtained are as follows: (1) The etching rate with CF₄+O₂ is 4-50 times langer than that with Ar, and is 10-20 times larger than that of purely chemical plasma etching with CF₄+O₂, because of cooperative interaction between ion bombardment and chemical reaction. (2) In sputter etching with CF₄, C remains at the Si surface. With the CF₄÷O₂, C concentration decreases as O₂ ratio increases. C is removed from Si surface by reaction with O. (3) The etching rate dependence on ion energy and CF₄ O₂ flow rate were investigated by means of estimation of incidence ion energy, observation of plasma circumstances and measurement of sputter etched surface temperature.

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This paper deals with the applicability of the Hertzian fracture test for measuring the microstrength which may govern fracture resistivity and machinability of the brittle materials for fine parts and cutting tools. Based on the analysis of the limitation of the test, a new procedure is designed, which has a distinctive feature of detecting fracture by acoustic emission from the tiny Hertzian crack of a few μm in diameter on the specimen surfaces. Microstrength measurements are successfully carried out on the specimens of glass, silicon, sapphire, natural diamond and synthetic one. All of these specimens show the remarkable size effect in the strength and high microstrength of the same order as theoretical value. Useful data for understanding the microfracture phenomena in brittle materials are obtained by this test. The average strength of 15 GPa is observed on diamond specimens when loaded by the indenter of 5 μm tip radius. This level is more than four times higher than that reported so far.

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Human body motions during simple loading and unloading operations are analyzed from physiological and kinematic points of view. The operational motions are projected to the sagittal plane and restricted as the planar motions. A two-dimensional model of human body consisting of nine equivalent rigid cylinders is proposed and the equations of motions are derived. Series of simple loading and unloading motions of an operator are taken from the side employing a 16 mm high speed cinecamera. The two-dimensional coordinate data of individual body segments are taken into a mini-computer frame by frame with use of a graphic tablet. The computer graphics are utilized to display the motion patterns of the operations, the loci of the body center of gravity and the correlations of the angles among the major body joints for detailed analysis of the operations. The forces and torques acting at individual joints are also estimated by solving the equations of motions based on the motion data, and the operational motions are examined quantitatively.

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This paper formulates the problem of how to operate flexible manufacturing systems (FMS's), and examines the effects of five possible procedures, which reduce or eliminate interference among the stations, on the system productivity. It is shown that it is prerequisite for obtaining high efficiency to balance the load at each station as evenly as possible. Provision of buffers in this case according to the variation of processing times at each station will improve efficiency. Scheduling should, then, be considered. This is particularly so when the number of buffer capacity is limited. For the job shop type FMS, input control, which means limiting the launching number of units to the FMS, should be exercised to reduce the buffer capacity required, when the number of buffer capacity is limited as usually is.

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In order to explain the mechanism of saw-toothed chip formation in metal cutting, it is necessary to know the deformation and fracture property of work material. In this study, the dynamic torsion test was carried out under the condition corresponding to that in the cutting experiment about the temperature rise at deformation zone. The 0.2%C steel, the 304 steel and titanium were tested at various temperature. Further, the conditions of saw-toothed chip formation were also discussed theoretically. The results obtained are as follows: (1) From the result at room temperature, the fracture strain γ_f for the 0.2%C steel and titanium were obtained as γ_f=2.0 + 0.004σ and γ_f=1.2 + 0.001σ, respectively, where σ is normal stress (MPa) acting on the shear plane. The mechanism of saw-toothed chip formation under the same cutting condition can be explained as the ductile fracture caused by over strain. (2) In high speed torsion tests at high temperature for the 0.2%C steel and at room temperature for the 304 steel, an unstable flow was occurred. Therefore, the mechanism of saw-toothed chip under the same condition can be explained as an unstable flow caused by thermal softening.

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This paper deals with the control problem of spare parts for mass production items. After formulating general relations between production patterns, product life and part life characteristics; and products still-used quantities and demands of spare parts, a computer program to seek these relations was developed. Using this program, the behaviors of products still-used quantity curves and spare parts demand curves were investigated. This revealed that from the viewpoint of controlling spare parts products still-used quantity curves can be classified into three groups according to the coefficient variations of product life distribution functions. While, spare parts demand curves can be classified into eight types. Finally, the policy to control spare parts was framed, taking holding costs of spare parts, fundamental classification of products still-used quantity curves, difficulty of predicting the product life and easiness of estimating part life into consideration, and design of parts reliability in order to ease the control of spare parts was discussed.

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The dissolution behavior of Co, Mo, Ni-Cr-Co alloys and Ni-Cr-Mo alloys has been studied in 3 mol/dm³ NaNO₃ solution at 30°C. The polarization curves and the dissolution current efficiency were measured in a flow cell. Co and Mo were always active at the potentials and current densities where Ni-Cr alloys were passive and secondary passive. These components promoted the transpassive and secondary transpassive dissolution of the alloys, dependent on the Cr level. The additions of more than 40%Co or more than 10%Mo to the about 10% Cr alloys resulted in the disappearance of the transition from the transpassive to secondary passive state. The current density establishing the onset of the secondary transpassive dissolution decreased with increasing the Co or Mo content. For the alloys containing more than 20%Cr, the effects of Co and Mo had only a secondary importance on activation of the secondary passivity. The effect of Mo on promotion of the transpassive dissolution was discussed briefly by XPS study of the surface film.

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In order to realize the high accuracy continuous path control, the steering apparatus appended to servomechanism is proposed in this paper. As usual the velocity vector modification has been applied to the continuous path control system, namely, the vector is set as the movement velocity of the servomechanism, being modified by the deviation from the trajectory, in addition to the method, the velocity vector is rotated at the direction to reduce the deviation in this new method, so that both the offset at circular path and the overshoot at cornering point are corrected by this steering apparatus. The practical use of the steering apparatus is recognized from the results of simulations and experiments and the index of this system design are indicated.

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In this paper, a coefficient of statical friction on the interfaces is named a coefficient of impulsive friction μ_i, and its measuring method is presented. The apparatus is symmetrically set to the axis of a vertical hexagonal pillar (test piece), and the opposite sides of the pillar are holizontally pressed by the end of two similar rectangular plates (test pieces; both with a slit which vertically reflects the shearing stress waves to change them into the compressive stress waves). The μ_i is theoretically calculated by using the stresses produced in Hopkinson bars which are screwed up on the test pieces. A gained μ_i is proved to be realizable when η is nearly unity. The η is the ratio of applied impact energy to propagated energy, calculated from stresses in each part of apparatus which are obtained experimentally and theoretically. By the measurement of μ_i about the ground test pieces of steel, it is shown that the proposed method is reliable and that the μ_i is smaller than the ordinary coefficient of kinetic friction.

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This paper presents an analytical method by which dynamic characteristics are clarified in a toothed belt system. In the belt system, variable tension and initial static tension act on the belt to transmit variable torque. The analysis assumes that variable tension is smaller than initial tension, and that the action of the former does not affect deformation caused by the latter. The dynamics of a meshing belt appeared through two different but related types of characteristics. One is static deformation, and the other dynamic response. The model used for analyzing the meshing belt is determined from the deformation and response in one tooth of the meshing belt. A method for calculating the elemental constants of the model is also shown. Dynamic characteristics were calculated for a simple belt system by using the model mentioned above for the meshing part of the belt. In the experiments, deformation and response were measured during meshing with plural teeth, and frequency characteristics were measured for the simple system. The computed and experimental results agreed fairly well. It was clarified that the analytical method is suitable for deducing the dynamic characteristics of a toothed belt system.

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Measuring Methods of straight motion error and straightness error of machine tools have been studied and the following conclusions are obtained. (1) Five components of straight motion error of machine tools can be obtained simultaneously and accurately by tracing the known surface profile of the straight edge master on the table with five differential type electric transducers, being attached to the spindle. (2) When the surface profile of the straight edge master is unknown, the components of straight motion error and the surface profile of the straight edge master can be obtained simultaneously and accurately by three points methods However, nine transducers are necessary in this case. (3) The straightness error components of the measured vertical type milling machine are very small, less than 3 μm for 500 mm length of motion, but the angular error components, approximately 80 μm/m, are relatively large.

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