[in Japanese]

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One of the ideal wheel with super-abrasive grains may be the pored type with metal bond which is easily able to remove chips from the surface of wheel and makes grinding temperature low due to the high ratio of heat conductivity. The present paper reports the developing process of metal bond diamond wheel with the bonding bridge and the porosity which the pored type of vitrified bond diamond wheel has. In order to establish the reliable adhesion between metal and diamond, the wettability and the thermal erosion of diamond are investigated for the several combinations of metals. The built bridges of bond are observed among diamond grains with metals heated in vacuum and are strengthened by the phosphorating treatment which provides 10 to 50 MPa of the bending strength to wheel. It is indicated in a few grinding tests that some of newly developed diamond wheels have the superiority to the pored type of vitrified bond diamond wheels.

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With the increase in memory density of the disk storages, surface roughness of magnetic media is demanded to decrease for smaller flying hight of the magnetic head. Coated magnetic media on the disk surface is conventionally finished with the abrasive tape. It has been difficult to get fine texture having surface roughness R_p less than 0.15 μm by using conventional method. In this report, the followings are described ; (1) The floating phenomenon of the lubricated abrasive tape according to the increase in disk rotation has been found. (2) The grinding rate of coated magnetic material can be evaluated by measuring the amount of ground residue on the abrasive tape. (3) Surface roughness R_p of the coated magnetic disk has decreased by finishing using abrasive tape floated as same distance as the tape surface roughness R_a.

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Generally, in the laser marking, surface roughness or grooves produced by laser irradiation are utilized for distinction; however, it is hard to distinguish the marked characters or symbols clearly. In this report, the laser marking of IC plastic package making use of the change in color has been described. By this marking method, the characters and symbols marked can be distinguished clearly. Effects of laser irradiation conditions for the change in color are studied, and the laser marking experiment of IC package, which consists of SiO₂ powder, carbon black and epoxy resin matrix is conducted. Occurrence of the change in color is controlled by varying irradiation power, irradiation time and irradiation atmosphere. It is found that the change in color occurs under the suitable energy power density, and the O₂ gas has the effect on shortening the irradiation time until the change in color occurs. The mechanism of the change in color can be explained as follows : after epoxy resin matrix and carbon black are removed, SiO₂ powder is melted by laser irradiation; SiO₂ powder which includes many pores are sintered; this sintered SiO₂ changes the color from black to white by diffused reflection. These phenomena can be applied to laser marking of IC package for subtle distinction.

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The 1st report described the construction of the knowledge representation system which compensates for errors of a model by experimental knowledges based on a combination of fuzzy inference and theoretical model methods for cutting operation plan. But on cutting operation plan, it is also necessary to have the knowledge representation system which adopts effectively many models which are related mutually. This report describes the construction of the advanced system which has a hierarchical structure in which parameters of higher-level models are decided by lower-level models, so called the multistage inference. It has been applied to predict vibration constants, and the limit of chatter vibration on both two, and three-dimensional cutting.

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The present paper deals the profile of a ground surface under successive plunge grinding considering the thermal stress, the attraction force of a magnetic chuck, the variation of a depth of cut due to the thermal deformation and the shape of preground surface, both theoretically and experimentally. The process of forming the profile of a ground surface in a series of plunge grinding is estimated by an approximate analysis taking the above-mentioned factors into consideration and is also precisely analyzed by a finite element method. The consequences are compared with the measured profiles of ground surfaces. The main results are as follows : (1) The straightness of a ground surface is gradually improved by decreasing the wheel depth setting with the number of grinding passes and, moreover, is efficiently improved by setting the wheel depth of cut at the bottom of preground surface. (2) Around the workpiece corners, the residual stock removal is increased by the local thermal bending deformation. (3) A change of the workpiece shape with the number of grinding passes roughly agrees with the approximately analyzed results.

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This paper describes the observation of spark locations in EDM processes. A new method for the in-process detection of spark locations is proposed in order to obtain the relationship between the process stability and the distribution of spark locations. Each spark location can be obtained from the current ratio of branched electric wires which are connected to the tool electrode by a sufficient distance maintained. From the results of experiments using this method, the following conclusions are obtained : (1) Spark localizations are apt to occur when the eroded depth becomes deeper. (2) The spark localization is caused by the vicious circle which is an iteration of the contamination of dielectric fluid and the reduction of dielectric strength of the fluid. (3) When the eroded depth gets much deeper, the spark localization becomes more serious, and finally an abnormal arc appears.

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A method for estimating the geometrical elements of screw threads is proposed. This method is based on the method of least squares and enables to obtain unknown geometrical elements, namely a position and an attitude of a screw axis, a pitch, a flank angle, a taper angle and a pitch diameter, from measured coordinates values of screw surface. A screw thread being treated to be three-dimensional, the method also has a capability to estimate form deviations in addition to the above elements. According to experimental examinations on some thread plug gauges which are performed by using a coordinate measuring machine, the method shows an expected performance, giving good results in the estimations with respect to the geometry of the specimens. In particular, the method is considered to be available for automatic inspections of screw threads by means of coordinate measuring machines.

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We have succeeded in constructing AFM using an optical fibre and a lever. Our AFM has a silicon dioxide V-shaped microcantilever with sharper tip radius than a commercial pyramid shape one by the silicon processing techniques combined with newly realized not only anisotropic etching but iso-one Si(100) surfaces. One of other superior techniques is that the output laser power through the optical fibre is controlled to be constant within more or less 1.0% by use of AOM (acoustic optical modulator). We also try to observe AFM images of PMMA (polymethyl metha acrylate) gratings which is soft material and to discuss the image differences when we use both the bigger protrusion on the lever and the smaller one.

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This paper describes the method to input the three dimensional information directly. When three dimensional model is constructed in CAD System, the position vector and rotation vector should be input. The input device which is designed in this study is able to input the rotation vector directly by new effective method. The primary factors which influence the accuracy of this device are the position of measuring point and the uniformity of speckle pattern in all measuring points. And to draw out the ability of this device enough, the three dimensional display system by using the method of binocular vision is developed. It is possible to operate as if the three dimensional model is gripped by hand when these devices were used together.

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The axial tension of the bolt in plastic region tightening is influenced by the yield point load of the threaded portion under combined loads of axial tension and thread torque induced by tightening, namely interaction curve for yield. However the traditional estimation method for the interaction curve of the threaded portion has some problems. Firstly, a new estimation method for the interaction curve of the threaded portion is proposed based on the flow theory. Secondly, a combined load testing machine is developed in order to apply the tensile and torsional combined load on the threaded portion of the bolt, and the interaction curves of the threaded portion are obtained experimentally. In conclusion, it is shown that the new method is superior to the traditional one considering only the local yield condition.

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There are some techniques which combine phase-shifting interferometry and two-wavelength interferometry. In this paper, a new algorithm that is called fringe-counting two-wavelength method is presented for the technique. In this algorithm, integer fringe orders are counted on the basis of the fringe patterns for the two wavelengths and fractional orders are determined from one of the two fringe patterns. The algorithm is compared with the equivalent wavelength method through discussion and simulation. An experimental measuring system was constructed with the measuring range of 3μm. The results of measurements for a polished surface with an indentation and a surface with steps confirm the above comparison.

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The nonlinear equation of the rotational vibration of a pair of spur gear has a restriction that the analytical solution of the equation cannot be obtained. If the nonlinear equation of vibration has not this restriction, it will be very useful. The Linear Approximated Equation (Abbreviate with LAE) of vibration, which has the analytical solution, is derived by converting the varying spring constant of meshing gears to “the equivalent exciting force”. The linear model of vibration, which can be used to analyze the vibration due to any tooth profile error with any shape when the pair of spur gear has any rotational speed, any load and any contact ratio, is presented in this paper. As a result of the investigation of the applicability of the LAE, it has been cleared that the LAE can be applied in wide range of the amplitudes and shapes of the tooth profile errors. The analytical solution of vibration of the LAE, which is derived by analytical method, agreed well with the result numerically calculated by the exact nonlinear equation of the vibration.

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Static and dynamic characteristics of NC machine tool's feed driving system are very important because they determine servo characteristics and machining performance of machine tools. The conventional methods for measuring these characteristics require many measuring apparatus and are time consuming. Here, a simple method is introduced for measuring static and dynamic characteristics of NC feed driving system. In this method, the static characteristic is found from the relation between amount of lost-motion and armature current of servo motor. For dynamic characteristics, the slider is accelerated and stopped suddenly and the generated inertia force is used to vibrate the slider on the condition that position loop is switched off and only velocity loop is switched on. Dynamic characteristic is found from the transfer function between armature current of servo motor and vibration acceleration of driven part during the vibration. The results by this method agree well with the results by conventional methods.

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This paper proposes an evaluation method of a machined shape with free-form surfaces and describes the basic way of thinking for the evaluation in which free-form surfaces are classified into a style surface and a function surface according to the application purpose. The evaluation items of a style surface and a function surface are determined as a unit normal vector and a positional vector respectively. The transformation from a designed shape to a machined shape is assumed as a model of a coordinate transformation, and the permitted transformations in the evaluations of a style surface and a function surface are clarified. The evaluation procedure based on the detection of positional vectors and unit normal vectors at sixteen arbitrary points on a patch of a machined surface is described in detail. In addition, the validity of the proposed evaluation method is examined by a computer simulation.

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The expert systems for grinding process have been proposed in recent years. But their regions of applications are limited and do not considered wheel dressing. On the other hand, machining data base for the process is available. But its use is not always possible under the disturbance of the process in workshop. This paper treats the construction of expert system for establishment of operating conditions in grinding, by getting the data from workshop. By the system unskilled workers will be able to make use of the knowledge and experience of skilled workers. The system includes programs that, (1) selection of the best wheel from among available wheels, (2) determine wheel depth of cut, feed and wheel speed for grinding, and depth of cut and feed for dressing, and (3) indicate routine for solution of trouble in grinding process. And the system has been built with production system which describes the notion of condition-action pairs, by LISP on micro computer.

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Since an intersection curve of two surfaces can be traced from a point on the curve using established methods, problems of determining all the starting points each of which belongs to the respective isolated intersection curves of two surfaces are treated. Methods developed here include detection of possibility of the critical case where two surfaces just contact. In this paper, two techniques for the detection are introduced. One is a pure theoretical approach and the other is a semi-theoretical but practical and efficient method. In the pure theoretical approach, all the singular points on intersection curves of two surfaces, one of which is translated along a definite direction, are searched. In the practical method, instead of the translation of one surface, all the probable point-pair of the initial approximate points for intersection curves are searched with efficient convergence to true points on the intersections. Examples for complicated shapes are shown.

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A method is described for calculating intersections between two arbitrary surfaces. This method can be applied not only to every type of surface, but also to offset surface or envelope which is not representable in terms of a basic functional forms. In this method, all surfaces and surface data are expressed by two independent parameters. This method comprises two essential processes. The first is to detect the intersection points between two surfaces by successive unidimensional searches. The second is to trace intersection curves by solving initial value problem by using the intersection points obtained as initial points. The singular points on intersection curves can also be detected by using the same successive unidimensional searches. The algorithm presented here provides adequately accurate results.

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