Skilled machinists can predict intuitively trouble in workpiece for cutting by glancing at the machine part drawing. Such machining know-how gained through long experience may be regarded in a sense as the fuzzy object. In this paper, a rational way for the acquisition of and model representation of this know-how is discussed. The following became clear after the investigation : (1) Through an analysis of the fuzzy partial order relation among machine part drawings, the attributes of the machine part which show a tendency to develop cutting trouble were clarified. (2) By identifying machinist subjectivity with the fuzzy measure, the know-how of the trouble prediction could be represented by a structural model using the fuzzy integral.

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A process planning system requires much information about the product, most of which is decided at the product design stage. When the form features created by a designer match the machining features recognizable by a process planner, it is straightforward to determine machining features from product design information. When the product design features do not match the recognizable machining form features, the process of feature extraction becomes more complicated. This paper describes a method of feature extraction for cavities by calculating cutter center paths. The machining process plan, the cutting tool selection and form tool design, and NC cutter paths are determined based on the extracted milling features.

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In this paper, the optical measuring method of fine scratches on mirror surfaces, such as the magnetic memory disk and the block gauge is investigated. The theoretical background of this method is based on Beckmann's Kirchhoff Approximation which is the theory of scattering of electromagnetic waves. Emphasis is on quantitative measuring method of fine scratches by the non-contact method. The results obtained are summarized as follows : First, the profile of fine scratch can be approximated to the triangle scratch, because experimental results from the various profiles of scratches are in close agreement with those in computer simulations for triangle scratches of the same depth and width. Secondly, typical factors related to size of scratch are found by the zero-and first order scattering intensities and the scattering angle, which are obtained from scattering intensity distributions. And then the depth and width of a scratch is simultaneously estimated by them. Finally, the range to be measured by this method is from 0.05 to 0.4 μm deep, from 10 to 80 μm wide for the scratches resulting spontaneously on block gauge and the scratches fabricated by diamond cutting tools.

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The purpose of this study is a development of a simple strength design method of bolted joint applicable to the general case. Cylinder-cover bolted joint is selected as an example of the axisymmetric bolted joint. The cylinder-cover bolted joint is modeled using spring-beam elements and analyzed with finite element method. A new spring-beam model of cylinder-cover bolted joint is made taking the slip on the bearing surface of bolt head into consideration. Using this new model the relationship between the applied pressure and the stress in the bolt is analyzed. The axial stress and the bending stress in the bolt are measured by strain gages to verify the results from the analysis of the cylinder-cover bolted joint of various geometry. The obtained results are as follows : (1) A simple and useful method to analyze the stress in the bolt in the cylinder-cover bolted joint is proposed. (2) The analytical results show good agreement with the experimental results.

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This paper presents TTL (through the lens) double diffraction grating alignment method using checker grating. An interferometric method, which utilizes a novel pair of grating marks located on the mask and wafer, has been developed. This method have the following characteristics : (1) High S/N alignment signal can also be obtained using many processed wafers. (2) Alignment light doesn't expose the resist on the wafer. (3) The alignment signal is not influenced by defocussing on the wafer. (4) The alignment signal can also be detected during exposure, and real time alignment is possible. The performances for this method were experimentally evaluated, using several processed wafers. As a result, closer than 0.15 μm (3σ) accuracy has been obtained.

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Two methods are proposed to prevent chipping of the work corners in grinding of ceramics: one is to press a splint to the work end with a loading system (splint press type), the other to fix it to the work end with adhesive (splint adhesion type). The applicability of these methods are experimentally investigated in single point grinding and theoretically confirmed by estimating the deformation constraint of the work, i.e., the resistance to the penetration of the swelled work into the splint. It is found that the size of chipping becomes small under appropriate conditions : it is recommended to use soft splint such as aluminum under sufficient compression in the splint press type, and to adopt thin adhesive with high Young's modulus in the splint adhesion type.

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In previous papers an oblique cutting model taking account of up-curl of the chip and chip flow direction was proposed. In this paper, a cutting model also including side-curl of the chip and the cutting velocity difference along the cutting edge is developed. It is assumed that the deformation at any point on the cutting edge takes place as in oblique cutting model. The whole process of chip formation is treated as a combination of elemental oblique cutting models varying at each point on the cutting edge. On the basis of the cutting model the energy method is extended to predict cutting force components, radius of chip curl and others. From the numerical computation it is shown that the radius of side-curl of the chip easily changes from an infinite value in oblique cutting to a value of three or four times cutting width along the cutting edge in the case of large cutting velocity difference.

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The purpose of this paper is to discuss the method for improving the stock removal rate without growing the damaged layer in the mechano-chemical polishing. Polishing plates made of either tin or lead are used with a polishing fluid chemically active to ferrite such as hydrochloric acid. The stock removal rate can be increased by more than two times and the damaged layer of the ferrite can be reduced to less than one fourth as compared with those in the mechanical polishing process, when a tin plate and crystalline alumina mixed with 5% hydrochloric acid are used in the new polishing process. It is comprehensible that these good effects are obtained by electro-chemical action which is added to the mechanical polishing for the cause of composing the local cell between a polishing plate and a ferrite.

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A CAD/CAM system by a personal computer for machining of a free formed surface has been developed by using an optical measuring system for 3-dimensional (3-D) object shapes. This CAD/CAM system is constructed by an NC milling machining attached with an XYZθ table and a personal computer. The optical measuring system is constructed by a CCD image sensor and a laser, and the 3-D objects shape can be measured by this system without any contact. The measured values are accurate about 80 μm and are converted to NC program by an automatic programming function. By this system, a 3-D object can be easily formed by the NC machining. So the authors have developed an optical profile NC machining used light sensor. It is attempted to machining for an abutment tooth and a doll's face with a free form surface for application in practice of this measuring and machining system.

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The three-dimensional distribution of temperature, thermal deformation, and thermal stress in a workpiece during table traverse cross-feed surface grinding is computed numerically, and the effects on the dimensional accuracy, the holding force of the magnetic chuck, and the grinding cracks in the workpiece are discussed. The distribution of thermal deformation and thermal stress is determined by a numerical method developed from the relaxation method. From the results of the analysis, it is clear that the deformation of workpieces cannot be disregarded when considering dimensional accuracy, and that the magnetic chuck is not sufficient to counteract the thermal bending of the workpiece.

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This paper describes the plane finishing characteristics of a flat non-ferromagnetic substance (SUS304 stainless steel) by magnetic abrasive finishing process, that is the effects of the various working factors on the stock removal and the surface roughness are clarified by experiments respectively, such as magnetic flux density, circumferential speed of magnetic pole, working clearance, feed rate of workpiece, diameter of magnetic abrasives and thickness of workpiece. On the basis of these experiments, the finishing mechanism is discussed in detail and the characters of this finishing proess are represented summarily. In addition, it is found experimentally that flat ceramics and a silicon wafer are also finished precisely by this process.

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In laser beam machining of ceramics, crack formation is a serious problem for practical application. In the present paper, Q-switched YAG laser machining of zirconia ceramics was carried out. The formation occurrence and length of cracks are dealt with ; furthermore, blackening of surrounding material of machined portion is observed. Cracks are formed within the blackened region. The blackening disappears when the machined workpiece is heated up to about 700°C. The blackening is due to the reduction in oxygen content ; the disappearance of blackening can be caused by oxygen diffusion into the material.

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The purpose of this study is to establish the cutting method of fine ceramics under high temperature condition. Silicon nitride, which is heated by plasma arc, is successfully cut with a CBN tool. Cutting forces decrease with the increase of the heating temperature, and over 1000°C, they become below those of carbon steel cut under the same condition at room temperature. By raising the heating temperature, the chip shape changes from segmental type to flow type, and above 1550°C the formation of perfect flow type chip is observed. To reduce the wear of CBN tips and prolong the tool life, the cooled tool is devised, and it is observed that the cooled tool has 10 times longer tool life than that of conventional tool. The structural change of the material after cutting is examined through SEM, ultrasonic microscope and optical microscope, but no change is observed.

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The grinding of ceramics with diamond wheels has disadvantages such as low stock removal rates or reduction of the strength of workpieces. This paper describes scratch tests with single point diamond tools and grinding experiments with diamond wheels in order to analyze the grinding mechanism of ceramics and overcome these disadvantages. The following results were obtained. (1) Specific grinding energy of ceramics is strongly correlated with fracture toughness and hardness. (2) Chips are removed as a result of the generation and growth of cracks, so called “fracture machining”. (3) Fracture machining is achieved at a high depth of cut, and improves both the stock removal rate and the grinding ratio. (4) The crack layer induced by fracture machining at a 40 μm depth of cut and 20m/min table speed can be removed by the finished grinding using a # 800 diamond wheel and the bending strength of SiC results in recovering up to that of the base material.

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In this report proposed is a mixing law with which the lubricating and cooling moduli of mixed type grinding fluids with arbitrary concentration can be predicted from lubricating and cooling moduli of single component type grinding fluid. A separating law is then introduced to separate the lubricating and cooling moduli of each component from those moduli of two-component mixed type grinding fluids which contain mineral oil and surface active agents. By using the mixing and seperating laws on the lubricating and cooling actions, predicted grinding forces and workpiece surface temperature have a close agreement to experimental grindng results. So that mixing and separating laws on the lubricating and cooling actions can be considered as the effective method to establish a standard for proper selection and optimum concentration of several component mixed water soluble type grinding fluids.

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This paper describes an experimental research on monitoring endmilling process depending on the detection of spindle motor current.In endmilling, it was noted that cutting forces produce deflection of the endmill and workpiece which result in dimensional inaccuracies or surface error. For a reduction in machining error, constant cutting force is expected by means of detecting spindle current.Machining experiments with workpieces in inner eccentric circle shape going with a variance of radial depth of cut are carried out on a system fitted with an adaptive control function. The evaluation about the practical effectiveness of such a monitoring method is discussed and a uniformed effect on machining accuracy without increasing machining time is achieved.

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Effect of difference in supplying methods of alloying element (s) is experimentally studied. The methods are placing foil on a substrate steel plate, electroplating, placing powder and fixing powder with water glass onto a substrate. The elements are nickel and chromium. An electron beam oscillated to Y direction with electromagnetic deflection impinges on the element(s) and substrate and melts them, while the substrate is traversed to X direction. Melted thin foil (0.01-0.05 mm) do not mix into the melted pool of substrate because of surface tension. Although 0.1 mm thick foil mixes into the pool, the alloyed layer consists of piled slant layers of different nickel density. Oscillating the electron beam to X and Y direction improves uniformity of alloyed layer. Electroplating method gives best alloyed layer because the contact with the substrate is good. But electroplating is much laborious. Placing powder method give the similar non-uniformity in the alloyed layer as the foil method. The density stays nearly constant even if the placed mass of powder varies. The fixed powder method gives linear relationship between the fixed powder mass and the density. The components of water glass are not detected in the alloy. The best method among the four is fixed powder method.

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In this paper we discuss the cutting behavior in the chamfer of a tap for a large size threads with a geometrical analysis and experiments. We investigated three kinds of the taps an ordinary tap, a spiral fluted tap and a spiral pointed tap using the imitated cutting edges manufactured and analyzed the behavior in the chamfer of a tap by measuring cutting resistance. The results are as follows. (1) The connecting cut-length of a tap can be expressed by a function using factors, pitch ; P, the number of flutes ; N, flank angle ; δ, chamfer angle ; θ. The maximum connecting cut-length ; Z₁ ( max) can be obtained by the equation as follows : Z₁(max)=P{(1+tanδ)tanθ}/N.(2) The connecting cut-length of a tap ; Z₁ changes by a percentage of thread engagement ; K, that is, the size of a tap hole and its periodical change is shorter as the chamfer angle ; θ smaller. (3) Carrying out the analysis and the experiment for the tap where P=1-6, N= 4, it is clarified that the initial thrust force of a tap with large size threads where K=60-100% shows less than 100 N and in a spiral fluted tap it shows the minus thrust force.

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