今日, センサ技術が多岐にわたる発展を成し遂げてきた背景には, 新素材の開発によるところが少なくない.ここではセンサに関係する新素材としてアモルファス, セラミックス, 形状記憶合金などについて述べる.

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本稿ではOFGの原理及び開発状況を解説した.現在各方面で経済性, 信頼性の向上が急ピッチで進められており, 近い将来多くの産業分野で実用化されるものと考えられる.

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A Numerical Contouring Control Electric Discharge Machining system (NCC-EDM) has been developed to generate three-dimensional surfaces efficiently by use of pipe electrodes. Now there are various methods to stabilize the EDM, but in general a periodical jump of an electrode has been used to remove chips and gases generated by the EDM. However the jump reduces the machining speed. This paper proposes a new NCC-EDM in which copper pipes having 6 mm O. D. and 3 mm I. D. are used for making pipe electrodes. The pipe electrodes can be easily made by bending the copper pipes into required shapes, and then many 1 mm diameter holes are drilled in each electrode in the another direction of its movement. Dielectric is sucked with chips and gases through the holes by a pump which is installed separately from the NC ED machine. From the results of the experiments, it is confirmed that this method makes it possible to maintain the stability and high efficiency of the stock-removal-EDM without any electrode jump.

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This paper presents a description of a system developed by the authors for measuring the flatness of the blade of a silicone slicer and its practical use in design of a slicing machine. This system enables us to scan the blade surface without bringing the sensor into contact with it and represent the resultant data on the display, either as a contour map in colors or a bird's-eyeview picture. Relying on these forms of feedback from the system, we have succeeded in designing an improved blade-chuck which guarantees a high degree of flatness for slicer blades. This design has made it possible to significantly cut down on the breakages of wafers occurring in the production process and raise the slicing velocity, thus bringing greater efficiency to the production of wafers.

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The spherical SCARA robot is a newly developed robot for the operation on curved surface, especially on a sphere. In the previous report the basic concepts and characteristics are analysed. In this report the construction and specification of the prototype of the spherical SCARA robot are discussed. Then the hardware and software for controlling the prototype are considered. An arbitrary motion curve can be used to move arms and three axes are driven synchronously by the softwared DDA to obtain smooth movement. The methods to obtain large circle path and straight line path on the sphere are shown. It is possible to obtain any other paths by the method, as an example the stitching curve of the baseball is obtained.

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In this report, it is found that high accuracy and efficient drilling of ceramics can be done by using discontinuous pulsating cutting force and ultrasonic vibration of ceramics (USVC). The main results are as follows : (1) In order to confirm the drilling accuracy of ceramics by this discontinuous pulsating cutting force and ultrasonic vibration of ceramics, a quite new precision ultrasonic super position vibration drilling machine has been able to be created. (2) Experimental results show that high accuracy drilling of ceramics can be obtained with the same sense of operation as drilling of metal by this discontinuous pulsating cutting force and ultrasonic vibration of ceramics. (3) It has been verified that the torsional ultrasonic vibration core drill is suitable for high accuracy drilling of ceramics and the longitudinal ultrasonic vibration core drill is suitable for high efficient drilling of ceramics.

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Soft magnetic materials find common application in electronic and electrical engineering as well as in information technology. The nickel-iron family of soft magnetic materials exhibit very poor machinability as evidenced by the extremely short tool life which arises when machining using classical tool materials. In addition cutting operations lead to a deterioration in magnetic properties of magnetically annealed components. In this article the experimental results obtained when machining MUMETALL® with TiN coated HSS and other tool materials are reported. Results of investigations into the tool wear mechanisms and surface integrity are presented and discussed for the turning, milling and drilling operations. The detailed investigation of the scatter of tool life results obtained when milling with indexible inserts is explained in terms of reproducable quality of the cutting tools coated using the PVD process.

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The dissolution behavior on the tip and on the wall of tunnel pits formed on aluminum during DC etching in hot HCl solutions was studied. Initiated pits grow into a tunnel by crystallographic and auto-catalytic dissolution on the tip, independent of both the pH and the chloride ion concentration of a bulk solution. The tip dissolution proceeds under diffusion control at a rate of several μm/s, and then the tunnel growth abruptly stops at a limiting length when the tunnel tip may be repassivated. Although the tunnel walls must be passive during etching, they are subjected to general dissolution because of a high etching temperature. The tunnel widths increase continuously at a rate of several nm/s and the square cross section of the tunnels changes to circular shape.

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This paper describes a process and a phenomenon which were clarified experimentally in feed expansion honing. Feed expansion honing in the case of using conventional abrasive stone, had been considered to have some disadvantageous points, such as higher honing temperature, higher stone wear rate and rougher honed surface of workpiece, comparing with free expansion honing. If superabrasive stone will be used which cut easily and dull slowly, it is surmised that these disadvantages will be eliminated. Furthermore the combination of feed expansion honing and superabrasive stone will bring about higher geometrical accuracy and efficiency. The process of feed expansion honing is made clear by measuring tangential force, stock removal and residual stock, and the result explained that its process is similar to the one of plunge grinding. The higher honing speed can produce the higher honing efficiency and the lower tangential force, when superabrasive stones are used. So it is hoped to develop a new honing machine for high speed honing.

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This paper describes the synthesis of diamonds on sintered diamond surfaces by microwave plasma chemical vapor deposition, and its application to cutting tools. First, proper deposition condition of diamonds has been discussed. Sintered diamond which has non-metallic solvent is suitable as a substrate for the deposition of diamonds on the surface; when metallic solvent is used as a substrate, many cracks emerge on the surface of a sintered diamond. Methane concentration of 1% is proper. Under this condition, diamonds grow epitaxially on the surface of sintered diamond, and unite the contiguous diamond grains directly. When methane concentration is so high as 3%, both diamonds and amorphous carbon are deposited. The diamonds have pyramidal figure, and grow vertically onto the surfaces of sintered diamond grains. Secondly, a sintered diamond cutting tool covered with diamond film has been presented. This cutting tool wears little on the cutting of hot-pressed sintered alumina because of its high abrasion resistant ability. Thus, it is possible to use this tool for cutting ceramic materials.

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Even for diamond tool, the tool wear increases with cutting distance after on diamond turning of an Al-Mg alloy. According to diamond tool manufacturers, it is said that brown diamonds are stronger and tougher than yellow ones. It has not been made clear, however, what coloured diamond is preferable for cutting tools. On the other hand, Ikawa has reported that microfracture strength can be estimated by IR absorption coefficient on diamond crystals. In this paper, the correlation between the colour of diamond and the tool wear was examined on turning experiments of an Al-Mg alloy. Yellow, light yellow, white, light brown and brown crystals of natural diamond were tested as cutting tools. These tools have same crystallographic orientation and same ratio, RA, of IR absorption coefficient α₁ at wave length λ=7.3 μm relative to the value α₂ at λ=7.8 μm. The following results were obtained. (1) Microfracture strength on the brown tools is approximately 1.2 times larger than that on the yellow tools, according to the estimation with α₁ and α₂ measured. The wear rates of both cutting tools are, however, almost same in the stationary state after some primary tool wear. (2) The surface roughness using the brown tools can not be distinguished from that using the yellow tools at any cutting distance.

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The early fracture is investigated experimentally that occurs in the turning of hardened steel with ceramic tools, and the occurrence condition is clarified. And a method of evaluation is propounded for the early fracture toughness. A turning test is carried out with hardened SUJ2 steel (HRC66) and ceramic tool. The critical cutting speed decided by one-minute criterion is found out, and the influences for the fracture of cutting conditions are clarified. The main findings are as follows : (1) Black ceramic tools show normal wear and long life at lower cutting speed. But they show suddenly early fracture at high speed. (2) The critical cutting speed becomes high according to the decreasing of feed rate, depth of cut and the increasing of corner radius. (3) The critical cutting speed is decided by the maximum undeformed chip thickness. (4) The early fracture is affected by rather the cutting temperature than the cutting force. (5) The early fracture toughness of various ceramics tools is evaluated by the maximum undeformed chip thickness and the critical cutting speed. (6) The early fracture is controlled by the coolant.

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This paper deals analytically with improvement of the reduction effect of the transmissive force level on the hammering machine with the impact isolation anvil. In the case of light damping, drive frequency above a primary resonance of the hammer system and a long distant setting gap of the anvil head, the force from the hammer system gains in power more than that from the anvil system by increase of amplitude of the hammer's motion. Vibration interference is applied to improve of the reduction effect of the force level in addition to vibration isolation by means of the anvil mounted on an isolation spring. The two hammers are drived out of phase by the only one spindle. The twin type machine shows the efficient reduction effect in the above conditions in which the single type machine with the anvil is ineffective. Decrease of the reduction effect by disagreement of coefficient of restitution and mass of the work is small, but disagreement of the setting gap is influenced to some extent. The reduction effect was improved about 12 dB in experiment.

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A new systematic method by which approximate equations of deformation of laminate can be derived in arbitrary accuracy considering the thickness of each layer is proposed by extending the method developed for deformation of homogeneous thick plate in the previous papers. The approximate equations presented in this paper are solved for a laminate under sinusoidally distributed load at the upper surface, and the solutions are compared with the exact one by numerical calculation. The following results are obtained : (1) Existence of a layer with large thickness or strong anisotropic property in a laminate causes a reduction of accuracy of approximate solutions in the layer, and it has an influence on the other layers in displacement components but doesn't in stress components. (2) The accuracy of approximate solution in such a layer can be improved to about the same accuracy as the rest by dividing the layer into several ones with appropriate thickness or by adopting adequate higher order approximation for the layer.

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This paper describes a new measuring apparatus of cumulative pitch errors on small module gear having a large number of teeth. This apparatus has a detector composed of two thin plates perpendicularly intersecting each other and a ball or a pin feeler which is attached near the end of one plate. The feeler contacts with two facing gear flanks near the pitch circle simultaneously. Radial and circumferential deflections from the profile of ideal tooth surfaces are detected independently as electric signals by wire strain gages bonded to those plates of the detector. These signals are transformed into digital data and the data are memorized in a microcomputer. Based on these data, cumulative pitch errors are calculated. The measuring apparatus is controlled by a microcomputer and the results of measurement are obtained automatically. An example of measurement of a gear with 160 teeth whose module is 0.5 shows that the accuracy of this apparatus is within 3 μm and that its stability is well enough.

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An effective method has been proposed to evaluate the thermal deformation of an NC machine tool. This method uses a touch probe and a master block, as well as a mathematical model of thermal deformation derived based on the finite element method. Thermal displacement between the spindle and the table is measured for three directional components in Y-Z plane of the machine along the Z axis movement. Then, by determining the parameters in the mathematical model so that the measured thermal deformation fits the corresponding value of the model, each deformation of the head and the column as well as its change due to relative position is clarified. Experiments have been carried out by rotating the main spindle of a machining center without cutting to verify the effectiveness of the method.

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A precision alignment-pattern detection method using diagonal detection optics and twodimensional image processing technique has been developed to improve the alignment accuracy of X-ray exposure systems. This method features (1) consecutive pattern detection in an exposure field, (2) capability of detecting both lateral displacement and proximity gap between a mask and a wafer using the same detection optics, and (3) reduction of detection error caused by variations in the alignment-pattern fabrication process by using broad-spectrum (Xe light) illumination. According to the simulation of expected quantizing errors in image processing, a pixel resolution of 0.18 μm has been selected to attain a detection resolution less than 0.02 μm. The detection accuracy of an experimental apparatus was investigated, checking the expected error due to variations of wafer alignment patterns, resulting in a detection accuracy of ±0.02 μm for the lateral displacement detection and ± 0.06 μm for the gap detection, respectively.

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It has been shown that the static stiffness of an aerostatic bearing can be infinite by using an aerostatically-controlled active restrictor (abbreviated ACR). In the present paper, the dynamic characteristic of this infinite-stiffness aerostatic thrust bearing with the ACR is analysed. The ACR is a kind of surface restrictor, and its fluid resistance can be controlled by a restrictor ring supported by another aerostatic bearing incorporated into the thrust bearing. Therefore, this aerostatic thrust bearing with the ACR can be expressed by a two-degree of freedom spring-mass system. From the numerical simulation and measurement of the step response of the bearing, it is shown that the settling time of the thrust bearing is about 10 ms. From the analysis of the frequency response, it is shown that the ACR suppresses the vibration of the thrust bearing for a time-varying load whose frequency is less than 10 Hz.

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The oblique illumination and oblique detection method, which detects the alignment mark at the exposure position without using through-the-lens technique is proposed, and its characteristics and application limits are analyzed. The alignment mark consists of the 6 μm-width and 5 μm-longitudinal pitch diffraction patterns. The illumination angle is 75°, and 60°-diffraction light is detected. The stable detection is realized by a 4-wavelength (458, 488, 515 and 543 nm) laser illumination, in which the variation of the detected signal is 24% in the range of 0.5-1.5 μm of pattern depth, 35% in the range of 0.7-2.7 μm of resist thickness, compared with the signal detected by the single wavelength light illumination. The experimental results give a detection repeatability of ±0.02 μm (3σ) in the range of 1.0-1.6 μm of resist thickness and a detection error of ±0.03 μm (3σ) in the range of (-3) -3 μm of focal error.

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Thermal deformation of machine tool structures, especially the distortion of machine tool column directly introduces straight motion error and straightness error of machine tools. The purpose of this study is to develop the non-contact measuring method of the distortion of the column using laser spot detection system, to measure their thermal behaviour, and to compensate for the distortion of the column by controlling artificial heat sources installed in its rear sides. The thermal behaviour of a model column and an actual machine tool column was measured to examine the effectiveness of this measuring and compensating method. From these results, the measuring accuracy of the thermal displacement of the column was within ±2 μm, and thereby the straightness accuracy of the column could be maintained to better than ±2 μm/m regardless of the thermal disturbances.

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