A method realizing high accuracy even in the workshop environment for Coordinate Measuring Machine (CMM) has been investigated. In this report, we propose the correction method of scale error by Machine Checking Gauge (MCG), and the verification of the efficacy of this method by Ball-Plate.

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Making sure of relationship between probing points and uncertainty, multi measurement strategies are used. It is one of the techniques for evaluation of the uncertainty of measurement. Workpiece having bad form error is measured. On plane feature measurements, probing points are varied from 3 to 8.The measure is a point where 3 planes intersect. Error from strategy varies from 25 to2μm. This variation of error derived from the number of probing point is based on probing point distribution.

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In the ultra-precision machining which milling and grinding are applied, the present state and studies of three kinds of

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[in Japanese]

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Single-crystal silicon used in infrared optics and semiconductor-based products can be machined in a ductile regime to generate crack-free surfaces. However, the subsurface layer partially transforms to the amorphous state. In this work, the amorphous layer formed on Si (001) by plunge-cuts with a round-nosed diamond tool was measured quantitatively by laser micro-Raman spectroscopy. The extent of amorphization depends not only on the depth of cut and tool rake angle but also on crystal orientation. The extent of phase transformation is significant at the orientation angle 45 deg., and is insignificant at 22.5 deg.. The critical depth for ductile cutting reaches a maximum at 22.5 deg. Therefore, the 22.5 deg. orientation is preferable for ductile machining with lowest subsurface damages.

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A metal-resist composite thin film material is machined by ultraprecision cutting and fundamental machining mechanisms are investigated. The feasibility of direct planarization of LSI substrates by diamond turning has been demonstrated, which provides ultra-flat surfaces for three-dimensional stacking of electronic chips by pressure welding.

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We have developed a three-dimensional internal microscopic structure observation system based on a high precision milling machine. In this report, we apply this system to observe the defects in a cast aluminum alloy specimen. We compared optical microscope images with X-ray computed tomography images and/or scanning electron microscope images at the same position and showed this system has sensitivity to the roughness of the specimen surface. Microscopic cavity structures were segmented and reconstructed from serial high resolution digital images.

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[in Japanese]

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Recently, the necessity of the measurement on the ultraprecision machining of asphere shape such as optical devices is rising. In the conventional contact type of measuring method, there is a problem with a drift of the transformation of the probe by the measurement pressure and the temperature change. Then in this research, it is proposed to use it for the air bearing slide a high rigidity, a low thermal expansion, and made of the light ceramics, and the simulation of the measurement accuracy was done with the comparison of a conventional material. Moreover, the air baearing measurement probe was actually produced in trial with the ceramic, and the measurement result was discussed.

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Demands are increasing for micro aspherical lenses in various optical devices and the micro glass lenses are generally moulded by glass molding process with micro aspheric dies and moulds made of ceramic such as tungsten carbide. These dies and moulds are mostly ground with micro diamond wheels, but require additional finishing process as the mould size become smaller and the required accuracy becomes higher. In the previous paper, a lateral ultrasonic vibration assisted polishing machine/system is developed in order to finish the micro aspheric moulds1). In this paper, circular vibration assisted polishing system was developped in order to improve surface roughness furthermore and its polishing characteristics were tested with the tungsten carbide workpiece

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The concept of microfactory was proposed about 20 years ago. This term means to minimize a production system to

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Metal screws are often not appropriate for surgical implants of osteochondral fractures as they may damage their adjacent articular cartilage. We have recently manufactured a micromachine to process patients' bone into bone screws, which is ideal material for implants because of their biocompatibility and osteoinductive ability. The bone screws can be optimal devices for osteochondral fractures. In this lecture, we report on the development of micro machine tools to process bone screws in the surgical theater.

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In the shearing, clearance has a significant influence on the accuracy of shearing products. Therefore, it is inevitable that the machining accuracy will degrade when we carry out the shearing with positioning error of tools, that is to say, under the condition of uneven clearance. Then in this study, we develop a small punch press on a trial basis which is installed a method of tool position correction before the shearing and a method of tool position monitoring during the shearing which is devised newly in this time. And the effectiveness is investigated.

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As a training in mechatronic design, a NC desktop milling machine has been developed using commonly available mechanical components and electronics. Numerical control functionality compatible with G-code was realized using a motion controller and graphical user interface as a virtual control panel. Additional functions to generate 3D figures were implemented. Machining results show its capability to machine micro-shapes on aluminum alloy, cupper and pre-hardened steel with high quality.

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In micro-EDM, introduction of vibration assisted machining can dramatically reduce the machining time without increasing the tool electrode wear and making the surface roughness worse. In this reports, at first measurement results of machining time in vibration assisted machining are described. Secondly, measurement results of the relations between discharge current and table movements were shown in order to demonstrate the phenomenon of vibration assisted micro-EDM.
Then, using the machining method, we have tried to fabricate micro-square shafts and show the validity of vibration assisted micro-EDM.

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It is difficult to evaluate tool wear in micro-turning, because the tools are smaller than conventional one. This study presents a tool wear measuring method in micro-turning using microscope, CCD camera and image processing technique. The accurate 3-D shape of a cutting edge can be recovered from image focus based on Hadamard transform. The high speed and high accuracy capability of the proposed method is demonstrated by experiments.

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Various kinds of research and development about a micro machine tool are now carried out at the companies, the research organizations, and the universities. However, the technical base of the micro machine tool design is not established yet. We take study on an application of light alloy to the micro machine tool, and developed the micro lathe made from an aluminum alloy. We performed experimental study on the consumption power of the micro lathe, and on the relation between depth of cut and surface roughness about brass cutting. From these experiments, it became clear that the application possibility of aluminum alloy to a micro machine tool.

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The miniaturization of many machine parts proceeds rapidly. But, a machine tool to process many machine parts is the size which is the same as former times. Therefore, there are many requirements toward the miniaturization of the machine tool from the market. We developed a ultra small size CNC lathe which machine width is the size of about 10 times of the diameter of the processing parts.And, that lathe is practical size, and easy to automate. In this paper, we discussed the result evaluated about the characteristics of this lathe, the effect on saving energy, the mechanical precision.

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In our previous researches, the coated-cemented-carbide tool is found so effective for the ultra-precision cutting of stainless steels and titanium metals. The surface roughness formed in ultra-precision cutting of titanium alloys is below 200 nm(Rz) until the cutting length of 2,000 m. However it is not adequate for producing the ultra-precision components. It is considered that the tool wear is caused by the cutting temperature rise due to the contact of tool to workpiece at high speed cutting. In order to improve the surface roughness and tool life, in the research, the effect of low cutting speed on ultra-precision cutting of a titanium alloy with coated-cemented-carbide tool is examined. Using the extreme low cutting speed below 1 m/min and depth of cut of 5 micro-meters, the surface roughness improves remarkably and attains below 84 nm(Rz). The flank wear of tool formed by ultra-precision cutting of beta titanium alloy at low cutting speed becomes considerably smaller than that at high cutting speed.

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[in Japanese]

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[in Japanese]

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This paper describes the effect of drilling tools on the machining accuracy of drilling holes on the CFRP (Carbon Fiber Reinforced Plastics) plates. CFRP is well known as difficult-to-cut materials which has very strong physical and mechanical characteristics. In order to improve the CFRP drilling technique, in this study, the two kinds of conventional twist drills are used in several drilling tests without any cutting fluids. It is found that the cemented-carbide drills are more suitable for the drilling of CFRP than the coated-cemented-carbide drills. The results show that the better quality of drilling holes is obtained by using the cemented-carbide drills.

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In the machining of metals, the chip formation influences largely on the cutting performance such as surface roughness of workpiece, cutting force, tool life and so on. The excellence chip formation requires a countermeasure for both tools and workpieces. When the tool is recognized, the rake face of tool where the chip is dominantly flown is very important. Especially in the case of ductile metals and alloys, the continuous chip appears and the rake angle increases. With this change, the cutting force decrease and, as a result, the cutting quality is improved. In addition, it is considered that the surface roughness of rake face may decrease because of the occurrence of more suitable chip flow. Simultaneously, the surface roughness of rake face becomes smoother so as to lead the frictional force smaller. In this study, the effect of surface roughness of rake face on cutting performance was experimentally examined. Cemented carbide tool is used as reference cutting tools. The cutting test was done repetitiously against aluminum workpiece(A5056).As a result, it is clarified that the surface roughness of rake face becomes intensively influential on the chip formation.

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The grinding wheel surface condition characterized by the distribution of cutting edges has strong influence on grinding results. In this research, the image processing system is developed for the evaluation of the distribution of cutting edges by means of measuring the numerous microscopic images on the wheel surface, and the structure of grinding wheel in which the image processing has become easy is examined.

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Recently the high removal rate grinding with high smoothness grinding has been increasingly becoming important. The influence of synthetic emulsion type grinding fluid on the traverse grinding characteristics of aluminum alloy under high depth of cut grinding, in the preaent research, is examined. From the results it is found that the characteristic obtained by using the synthetic emulsion type is much better than the emulsion type. Supplying the synthetic emulsion tyoe grinding fluid, the surface roughness of aluminum becomes below 1μm(Rz). However, the critical total wheel-workpiece contact number on the synthetic emulsion type grinding fluid is less than using the emulsion type including the chloride compound.

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In previous research, the ultra-smoothness vertical grinding method based on new concept is developed and ascertained useful. Using the grinder, in the research, the change of grinding characteristics of die steel SKD11 with the dilution degree of soluble type of grinding fluid is examined. The dilution degree ranges from 10 times to 500 times. For reference, in addition, the water is used as grinding fluid. It is found from the result that the most suitable dilution exists for obtaining the best smoothness surface.

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Surface preparation techniques to make atomically flat and defect-free SiC substrate are strongly demanded in the next-generation semiconductor technology. However, effective technique does not exist particularly for surface smoothing. In this work, a novel planarization technique we proposed is employed to processing sintered-SiC surfaces. Prepared surfaces are observed and characterized by optical interferometer and Nomarski differential interference contrast. Obtained images show that sintered-SiC surface is processed by the catalytic effect on the surface of transition metal such as iron and copper.

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In the previous research, polishing conditions of high pressure and high speed are found useful for the high removal rate polishing with ultra-smoothness polishing. The high removal rate polishing, however, causes the high temperature rise of polisher surface due to large quantity of heat generation. The high temperature rise damages the surface of polisher. To repress the temperature rise, in this research, the effect of water-flowing inside polishing plate on the repression of temperature rise is examined firstly and its method is ascertained useful. Under using the method, on the basis of the results, the relationship between the temperature rise and polishing conditions is investigated.

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In the polishing of the magnetic disk substrate, high pressure and high speed polishing is found useful for the high removal rate polishing. The removal rate is influenced by the real contact area between the substrate and the polisher. Therefore it is important that the relationship between the removal rate and polishing pressure is clear. The change of the contact area with polishing pressure is examined by using the image processing technique. It is found that the change depends on polisher surface structure. The contact area is referred roughly to increase with the increase of polishing pressure until finishing the disappearance of pore existing inside polisher.

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To polish the magnetic disk substrate by low cost, high removal rate polishing is strongly required. In the report, the influence of ultra-high polishing pressure on removal rate in polishing of a glass magnetic disk substrate is examined. The polishing pressure ranges 40kPa to 100kPa. In the use of new polisher, the removal rate steeply increases transiently to steady polishing process. The removal rate at 100kPa is about two times more than 40kPa. The polishing pressure has little influence on the surface roughness of polished substrate.

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[in Japanese]

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To clarify the effect of uniformity in wheel structure on the dressing mechanism of cBN vitrified bonded wheels, dressing experiments by rotary diamond dresser are conducted using two types of cBN wheel manufactured by a new coated method and a conventional method. Especially, the influences of uniformity in wheel structure on the topography of cBN wheel surface after dressing are investigated on the basis of three dimentional analysis with a multi-prove SEM.

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In this study, micro wear behavior of grain cutting edges in the grinding process with vitrified cBN wheels is investigated on the basis of three-dimensional analysis using a multi-probe-SEM. Especially, three-dimensional shape of micro-cutting edges generated by micro self-sharpening in the steady-state wear region is evaluated by means of three-dimensional fractal analysis. These results show that fractal dimension is regarding micro-cutting edges closely concerned to the changes in grinding characteristic values.

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Surface plunge grinding experiments using a grinding machine tool equipped with an active magnetic bearing spindle have been conducted over a range of grinding speeds from 60 to 260m/s. Moreover, Ultra-high speed micro-cutting tests with a model grain cutting edge and its simulation analysis using a finite element method have been carried out to investigate the material removal mechanism in Ultra-high speed grinding with cBN wheels.

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This study is a fundamental research to clarify a grinding mechanism of cBN wheel. An FEM analysis of a transitional micro cutting process with cBN grain cutting edge and circular grinding experiments have been performed. As a result, phenomena of transient removal mechanism which consists of rubbing, ploughing and cutting have been clarified.

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This paper describes the fractal analysis in respect to the wear behavior of cBN grain cutting edges. Basic grinding tests for producing individual grooves using a grinding tool with multiple cBN grit are carried out to clarify the wear characteristics of grain cutting edges in grinding process and the changes in 3-dimensional profile of grain cutting edge measured with a multi-probe SEM are evaluated on the basis of fractal analysis.

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The theoretical analysis of friction torque of crossed roller bearings has been developed considering the contacts between surface roughness asperities, traction under hydro dynamic lubrication, rolling resistance force and elastic hysteresis. The friction torque characteristics of a bearing with roller pitch diameter 124mm are studied. The major friction factor is the contacts between surface roughness asperities at low speeds and is the rolling resistance force at middle and high speeds. Traction under hydro dynamic lubrication and elastic hysteresis are confirmed to be minor and especially the later is also found to be negligible.

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In late years, many inverters (a variable voltage, a variable frequency control unit) are used with the air conditioner and the Uninterruptible Power Supply (UPS) etc. An electric corrosion occur to the bearing in the cooling fan used near the inverter happens frequently. This phenomenon is assumed a cause that a slight current is generated by the high frequency noise caused by the inverter, and the current flows to the bearing in long time. A lot of researches on electric pitting of bearings for the railroad vehicles have been done, but there is little research intended for the small ball bearings. In this research, the bearing characteristic when it is assumed to be a final purpose to investigate the cause in which the high frequency stray current corrosion happens, and rotates the bearing in the high frequency environment is examined. This is a basic experiment of electric pitting without turning on electricity for small ball bearings (693).

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[in Japanese]

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The purpose of this paper is to establish a database of fatigue life and reliability of rolling bearings. Fatigue life test of deep groove ball bearing #6206 under grease lubrication carried out with the use of fatigue life testing machine, and fatigue life distribution and the basic dynamic load rating are estimated from the test data.
The life tests are carried out for two load levels pure radial load and the load life exponent is also discussed on the base of the test results.

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[in Japanese]

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In this report, a fatigue life of linear motion roller guide integrated in two cages in each row are carried out by using a eight-series life test rig. The fatigue life test data and examined result for life formula is reported, and the life distribution condition of linear motion roller guide is compared with statistical distribution functions by using 2-parameter Weibull distribution, 3-parameter Weibull distribution, and log-normal distribution.

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This paper introduces the result of a fatigue life test data of ball bush which is a kind of linear bearings. Collected life test data is arranged by using log normal distribution, 2-parameter and 3-parameter Weibull distribution. Fluid polish is carried out for the outer sleeve raceway of ball bush and the life test result is compared with conventional ball bush which is only ground by internal grinding machine.

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This paper deals with the Ball Spline fatigue life distribution under simultaneously applied radial load and torque. Life test data are plotted by log-normal, 2-parameter and 3-parameter Weibull distribution respectively. The rating life is also derived from load distribution in ball spline. The of trained results are as follows: (1) The life distributions of Ball Spline are conformed well to the 3-parameter Weibull distribution function with a Weibull slope m=10/9 introduced minimum life γ. (2) The rating life and rating load for ball spline under the application of torque and radial load must be evaluated by the applied torque.

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In order to estimate the sliding-rolling contact fatigue life of the surface-hardened sintered roller based on the linear fracture mechanics, the crack propagation behavior was investigated under a sliding-rolling contact condition using the case-hardened steel rollers with three different sizes of fine axial tubular holes below the surface and the thermally refined steel roller with a fine axial tubular hole. The parameters m and C in Paris's law were obtained by using the relation between the crack propagation rate by the experiment and the stress intensity factor range by the calculation, and these parameters were finally expressed in terms of Vickers hardness. Using these parameters, the fatigue lives of the surface-hardened sintered rollers were estimated. The estimated fatigue lives mentioned above approximated to these experimental ones.

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[in Japanese]

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Generally, the gear noise has been decreased by designing the gear with the teeth number as large as possible to reduce the meshing transmission error up to now. This design method is thought about only the decrease of the gear sound, and it is not thought about the relation of the back ground noise in the car and the gear sound. However, this design method has the problem that the gear sound that has not been heard comes to be heard whenever the back ground noise in the car improves as the technology of the hybrid car improves in recent years. Therefore, we propose a new design method of the low noise gear, which according to the back ground noise in the car that is masking noise of gear sound. The proposed gear design technique is a method that the frequency of the gear sound is controlled as the gear sound is covered with the back ground noise.

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Excessive end mill vibrations decrease machining accuracy. The purpose of this study is to obtain a method of estimating end mill vibrations at cutting point from spindle head vibrations. For this purpose, frequency response characteristics between cutting point of end mill and spindle head was measured when end mill is excited at cutting point by a vibrator, and then end mill vibrations at cutting point was estimated from spindle head vibrations by using the measured frequency response characteristics. As a result of cutting tests and considerations, it was concluded that the end mill vibrations at cutting point estimated by using proposed method approximately corresponded with actual end mill vibrations.

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This paper proposes a monitoring technique for the in-process measurement of cutting force and the prediction of tool breakage in the high speed slotting with the small-diameter end mill, which is based on the newly developed visualization system with high-speed CCD camera, image acquisition and image processing. This system is able to measure the tool deflection and to predict the cutting force in process, it is useful for the monitoring of the cutting state.
In order to control the constant cutting force in process, the cutting force that this system predicted was used for the feedrate override control. As a result, the prevention of tool breakage and the control of the cutting force were confirmed by the feedrate override control.

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In order to support optimum design of cutting conditions on machining centers, now techniques that can measure and monitor cutting torque on processing are wanted. However, it is difficult to measure cutting torque on small diameter tool processing because of small range. The purpose of this study is to develop the system that can measure small cutting torque on processing. The measurement method is to detect torsion angle of magnet coupling in the system caused by cutting torque. This paper explains the system and considers calibration means of error factors to let measurement accuracy down. Recent Wire Electrcal Discharge Machine (WEDM) has reached machining accuracy of 1-2 μm and surface roughness of 0.3-0.5 μmRz. To improve the performance of WEDM, a high-frequency AC (HFAC) power supply is used for the finishing process. Meanwhile, the mean voltage while machining is 0 volt, which makes difficult to capture the discharge gap voltage for proper servo control of wire electrode position. Therefore, constant feed rate system has been adopted instead of servo control when using of HFAC power supply. It is one of major problems to process a super-fine profile. By adding a new electrical circuit between the workpiece and the wire electrode, the equivalent discharge gap voltage is properly detected, and the feed rate can be calculated properly. This new servo control method helps the improvement of the accuracy with super-fine profiles such as IC lead frame stamping die. And it also improves the minimum discharge gap with fine wire electrode, such as 4 μm with 30 μm diameter wire electrode, and 1.5 μm with 20 μm diameter wire electrode.

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