Diffusion bonding is a technique which can produce joints in the solid state. Initially, metal members are placed in intimate contact under some pressure. Then, heating these samples to a sufficient high temperature for a suitably long time, the atoms begin to migrate across the interface. So the diffusion bonding is accomplished. In this report, an applied method of diffusion bonding cast iron in the air. This method has been considered difficult over the past years. Experiments are made varying the conditions such as pressure, temperature, time interval, surface unevenness and roughness. Then the following results are obtained. It is possible to join cast iron in the air by diffusion bonding. The shapes of voids near the joint interface are closely related to the tensile strength of joints. Bonding pressure has influence on the plastic deformation of surface unevenness, and assure intimate interfacial contact, but gives no effect to diffuse the atoms. Surface preparation has an important effect to the tensile strength. Especially, when the bonding surfaces are exposed to the air, they are oxidized and poor strength is obtained.

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This paper describes an investigation of the behavior of a coupling model under gross sliding motion at the interface. The coupling model consists of two parts. One is an elastic part that is used to determine the dynamics of contact surface in machine tool structure. When the model is subjected to a large external harmonic torque, gross sliding motion takes place at the interface. The motion of the model is theoretically analyzed and analytic results is verified by experiments. It is concluded that the stick time at which two parts of the coupling model are sticked together at the interface decreases provided that the exciting frequency subjected to the coupling model is high, the maximum static friction torque at the interface is small and the transmitted friction torque is large. The maximum amplitude of damped vibration wave response of the coupling model is expressed by the frequency ratio, the ratio of maximum static friction torque to transmitted friction torque and the equivalent viscous damping ratio.

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The new rotating mechanism equipped with two pairs of spherical bearings, which are followed by polishing and hand working until the desired finish and contour are achieved, can be described here. This apparatus will be applicable to such a highly precise spindle as a roundness tester. The radius of a convex part is equal to or larger than that of a concave by a few micrometers, so the lubricant oil rouses spherical parts to squeezing action and prevents them from contact. The two drive systems for rotating axis are used. One is "indirect driving mechanism", of which the motor drives the spindle through gears and radial bearings for, vibration reduction. The other is called as "direct driving mechanism", then the axis of rotation is coaxial with the rotor part of the motor. It is difficult to compare both mechanisms owing to the difference of the ways of fixing the spherical bearings and the surroundings where two machines are situated, however, with the former development, the spindle radial motion under O.03μm and its repeatability under O.1μm can be obtained. The noiseless spindle radial motion of the latter one within 0.1-0.2μm and the variation of velocity under 0. 02% can be achieved. In order to achieve more accurate capability, at least two basic requirements must be met. These are lack of vibration and temperature control.

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In this paper the characteristics of the grinding temperature are experimentally investigatedin the vertical-spindle heavy surface grinding of mild steel. The main results are follows.
(1) In the grinding condition of sufficient self-sharpening, the area of heat source by thegrinding comes to the same apparent contact area between grinding segmental wheel andwork. The distribution of the heat source is considered uniform on the contact area.
(2) The grinding peak temperature on the contact area is comparatively low because themetal-removal rate par unit area of contact and the specific grinding force are small.
(3) The down slope of the temperature in the direction of the depth from the groundsurface is small because the contact length (direction of the work feed) between grindingwheel and work is long.
(4) The grinding peak temperature on the contact area has an up slope in the direction ofthe wheel running because of the increases of the flowing rate into work of heat.
(5) In case of the wide works, the temperature on the contact area becomes high.

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It is frequently observed that a PTP (point-to-point) robot shows unexpected singular motion in case of large displacement. This is because of the controlling method used whichattempts to give the maximum speed to any axis. In this report another method of controllingis proposed, which gives the same motion characteristics to all axes in the same period, justlike as cam-controlled. Computer simulation has proved that the resultant hand motion isvery similar to the given axes motion, and the motion locus is smooth and has no singularityby utilizing this method.

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In this paper, the authors report on the rigidity of a shaft supported by two or three linearmotion ball bearings and the load distribution in those bearings, both of which are analyzedtheoretically and confirmed experimentally. The main results obtained are as follows:
(1) When a load acts on the overhung portion of a shaft supported by two bearings, theposition of load-acting point has a great effect on the rigidity of the shaft, while the distancebetween two bearings has little effect on it. And the differences of load distribution andrigidity of two-bearing system and those of three-bearing system are small.
(2) When a load acts on the shaft portion between two bearings, the maximum distributedloads in the bearings increase in accordance with the increase of the distance between twobearings. In this case, if the third bearing is mounted at the midspan between two bearings, the maximum distributed loads in the bearings decrease considerably.
(3) When some preloads are given to the supporting bearings, it is very effective for theimprovement of load distribution states in bearings as well as for the increase of rigidity ofthe shaft.

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Industrial robots are used for supplying an automatic machine with some kinds of partsor for loading and unloading the works to the machine. In these cases, the robot arm movesintermittently. When the robot arm is driven at a high speed, positioning error at the settlement place (the cam-dwell mode) is generally drawn because of the residual vibration whichis caused for the lack of stiffness. This paper deals with a method of reducing a residualvibration rapidly. It is realized by inserting a spring-mass-damper system between the driving system and the robot arm. Here, we define the optimal parameters on the combinationof a spring, a damper, and a mass for the elastic support which has the steepest slope of theenvelope curve of the residual damped vibration. After an analysis, the optimal parametersare given by β=1 and ζ_d=1/√α. Where, β; ratio of the undamped natural frequencies of theelastic support and the robot arm, α; ratio of the masses of the elastic support and the robotarm, and ζ_d; damping ratio of the elastic support. Two practical examples of the elasticsupport are shown. One is a high speed positioning system of a robot arm driven by anindexing-cam mechanism and the other is the system of a robot arm driven by a pneumaticactuator.

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In the plunge grinding, measurements were done at the displacement amplitude of vibrating wheel spindle, the grinding force, and the roundness of and the loading metal's amount along the wheel surface, and discussion was made on the dynamic behavior of the wheel spindle. The spindle in operation has two surpassed frequencies; corresponding one to the rotary speed of wheel and its double one. The former is caused by unbalanced weight of the spindle and the latter is due to unsymmetrical bending rigidity of the spindle resulting from the existence of screw holes for fastening up the wheel shaft. Consequently, loading metal develops at stationary positions along wheel periphery. In process of time, while the former scarcely undergoes a change in the vibration amplitude, the latter increases in the tangential amplitude almost proportionally to the tangential grinding force. Its proportional coefficient is affected by grinding condition, especially rotary speeds of the wheel and the work.

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In weight-checking, packages to be checked, even though they may have the same mass value, are not clearly assigned to a certain group but there exists a zone within which the assignment is determined according to a certain probability. The zone of indecision is sometimes referred to as "Gray Zone" and the weight-checking accuracy depends on the characteristic in probability of the zone. "Gray Zone" can be divided into two portions; one is the zone due to the inherent characteristics of the checkweigher, while the other is the zone due to the disturbance. In this paper, assuming the disturbance to be stationary random vibration from a foundation of a checkweigher, the characteristic in probability of "Gray Zone", namely, the characteristic of the weight-checking accuracy is analysed theoretically and is investigated on computer simulation. As the result, it is clarified that the weight-checking accuracy can be calculated from the spectral density of the disturbance assumed above.

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In traditional plunge grinding, a constant infeed rate of wheel head is selected and grinding efficiency may in general become lower with better grinding quality. In this paper proposed is a new plunge grinding technique, in which the infeed rate of wheel head is linearly controlled with grinding time, for increasing grinding efficiency without detriment to grinding quality. In the new process the accumulated amount in grinding system decreases in the latter stage of wheel head infeed and then the grinding efficiency can be increased with a required quality and a given grinding allowance. Under a certain condition the new process becomes more advantageous in both efficiency and quality than traditional one.

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This paper describes design conditions for the coin diameter-thickness checker mechanism. The relations between the dimensions of coin and those of the mechanism are analyzed in order to obtain the static condition to check coins surely, and the dynamic coin motion is analyzed in order to obtain the limitation of minimum length in this mechanism. The results obtained are as follows.
(1) Large influence factors on diameter checker are round edge of coin, diameter gage height and truck width t₀.
(2) Large influence factors on thickness checker are t₀ and thickness gage width.
(3) The minimum length of coin checker mechanism l₀ can be written by l₀=δ·v₀+d. Where v₀ ; initial rolling speed of coin, δ; coefficient, d; coin diameter.
(4) If we design l₀ is equal to (1. 8-2. 0) × d, we can gain good characteristics of checker is the case of usual v₀ =0. 3-0. 4 m/s.
(5) The theoretical value in these results nearly fitted to the experimental value.

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The lubricant temperature rise in hydrostatic bearings becomes large under the condition of high load and high speed operation. Therefore the effects of lubricant viscosity change on bearing performance are not negligible. In this study, the performance characteristics of capillary compensated multi recess hydrostatic thrust bearings are analysed theoretically and experimentally considering the lubricant viscosity change. The relations between the lubricant viscosity change and the load carrying capacity or the bearing clearance variation are shown quantitatively. The close agreement was obtained between theoretical results and experimental ones. Consequently, it was pointed out that the hydrostatic bearings should be analysed considering the lubricant viscosity change.

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Variously heat treated tool steel SK 3 and high speed steel SKH 9 were machined with sintered CBN tools. Tool wear and cutting temperature were examined with regard to work hardness. Further, diffusion tests were conducted between steels and CBN grains or CBN tools to ascertain the possibility of chemical wear of CBN tools. The results obtained were as follows:
(1) Extremely large wear of conventional CBN cutting tools in machining of low hardness work materials is not the inherent chemical characteristic of CBN itself but the characteristic of mechanical properties of the tools depending on sintering mechanism.
(2) The average cutting temperature of CBN tool is fairly lower than that of carbide tool.
(3) When the hardness of work materials exceeds a certain limit, the chip becomes thin and sawtooth shape, and the cutting temperature tend to decrease with the increase of work hardness.
(4) Around the temperature of 1200°C, CBN grains are fairly stable for the reaction to Fe. But when they are sintered, B or Co around the tool surface tends to diffuse into Fe.

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The present paper deals with a feedback control of workpiece dimension in finish turning operation on an NC-lathe. In order to perform the control, a new equipment is developed by making use of laser tube and photoconductive cell. The measuring method is quite simple and effective results are obtained through various experiments. Tool post is automatically moved in the direction to reduce the error and as a consequence, the diameter error was suppressed within ±15 μm by the control.

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