The Selective Compliance Assembly Robot Arm (SCARA) is a newly developed robot for the use of small-lot batch assembly. In the previous report the characteristics of selective compliance effect were discussed and the experimental results on insertion were shown. The robot is controlled by an 8-bit microcomputer. In this report the hardware and the software of the controller are discussed. An arbitrary motion curve similar to a cam curve is used to move arms, and two axes are driven synchronously by the softwared DDA. Thus smooth movement is obtained. The results on repeating positioning accuracy, residual vibration and acceleration characteristics are shown. In spite of utilizing a low level microcomputer, the robot could obtain a sufficient speed up to 0.5 m/s which almost corresponds to the speed of a human operator.

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In this paper, the static behavior of the bolted joint interface is analyzed by the finite element method (FEM) in consideration of the joint interface boundary conditions which are adherence, slipping and separation. And the characteristics are considered theoretically on the deformation, slipping behavior and pressure distribution of the joint interface. The following results are found. The joint interface deformation and slipping displacement are decreased by the enlargement of the plate thickness, bolt head size and coefficient of friction on the interface. And the separate area of the joint interface is also decreased and the pressure is distributed more uniformly. Independently of the plate thickness, the half angle of the pressure cone is constant. The effective area of the connecting force increases in proportion as the bolt head diameter and coefficient of friction on the interface increase. But the area does not increase so large as the increment of the bolt head diameter. The joint interface deformation is influenced more effectively by the material of the base than that of the plate. The effective area of the connecting force increases in proportion as the Young's modulus of the plate increases and in the case of the base, it decreases.

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Abrasive cutoff wheels are fed radially into usual metal members, that is, steel, brass, copper and aluminium. The removal (feed) rate and grinding ratio are measured in terms of the wheel speed and the feed load which are chief variables on the working conditions. The performance of working is characterized by the average depth of cut; g. Increase of feed load gets g deeper and the removal rate higher for all members. At higher wheel speed, brass is cut off at higher rate and g is almost kept constant. In the case of steel, the higher wheel speed has the adverse effect on the removal rate. The higher removal rate brings on the more wear of wheel. From this performance, the product of removal rate and grinding ratio is presented to be a characteristic of efficiency or machinability. Cutoff of steel makes a difference in about twice the efficiency among wheels. The machinability of steel is a fiftieth of brass, and that of copper and aluminium mediate between the former two.

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Silicon wafers are usually polished mechanochemically using a cloth polisher. Their surfaces are not damaged, but their flatness deteriorates with polishing time. To investigate the cause of flatness degradation, the surface shapes generated in silicon wafers with plane, cone-shaped and saucer-shaped polishers were simulated by measuring polisher deformation characteristics and silicon wafer polishing rate. A difference between the simulated and experimental values was seen, and this difference, or flatness degradation, resulted from the fact that: (1) A porous polyurethane cloth polisher has viscoelastic characteristics. (2) The work is inclined by polishing force, which consists of frictional force and squeezing force caused by the work edge. (3) Viscous deformation due to work inclination becomes larger in the center region, as compared with the inner and outer region, of a polisher. (4) As a result, a non-linear average pressure distribution occurs over the work, where the pressure is higher on the outer periphery of the work. A very flat surface could be obtained when the work inclination decreased through making the work plate support point low or when a very slightly inclined cone-shaped polisher was used.

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This paper describes a method of generating a curved surface by using the data at the arbitrarily distributed points. In this method, the heights of the surface at the rectangular grid points are firstly estimated from those data at the arbitrarily distributed points, and then a curved surface is generated from the estimated heights at the grid points by using Bezier, B-spline or Coons rectangular patches. For assuring the validity of the method in this paper a curved surface is generated by using the data at the arbitrarily distributed points of an analytically well-known surface, and the error of the generated surface is analyzed. Since arbitrarily distributed data points can be handled for generating a curved surface, it is possible to collect more data from the surface of a clay model with higher curvature.

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For realization of high precision centerless grinding, high rigidity and high precision servo-controlled regulating wheel spindle system is newly designed. On this system truing method of regulating wheel is studied for accuracy and the followings are concluded: (1) Truing accuracy with single point diamond dresser is by far lower in roundness and profile comparing with motion accuracy of wheel spindle and dresser feed. (2) Newly proposed truing method of regulating wheel with grinding wheel gives higher shape accuracy by one order comparing with conventional method. (3) Ground surface of regulating wheel is preferable in both friction and wear characteristics, and redressing life is much extended. (4) Ground regulating wheel excellently improves machining accuracy. For example, roundness error improves from 1.7 μm to 0.2 μm and surface roughness from 0.32 μmR_a to 0.12 μmR_a in comparison with the case of conventionally trued regulating wheel.

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This paper deals with a tachometer by using the basic property of the moiré profile. This tachometer has the moiré profile detecting device with two radial gratings and the photo-transistors and the simple operational circuits mathematically analyzed. In terms of the experimental results, it is revealed that the linearity of the output for the speed of rotation is less than one percent variation, and that the ripple content of the output is one-fifth of the conventional tacho-generator. The experimental results are in good agreement with the theory based on the simulational model. In addition to the reduction methods of the ripple content at the low speed of rotation is suggested.

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This study aims at the development of the strength design system applied to the general bolted joints, and as a case study, the strength design. method for the connecting rod joints has been treated. From the standpoint of the systematization on the strength design for the general bolted joints, the connecting rod joint is modeled to the prismatic parts clamped by a set of bolt and nut (singlebolted joint model), and the strength design of the connecting rod bolts is discussed through the strength design for the obtained model. Furthermore, the experiments concerning the stress on the bolt are performed in order to investigate the applicability of the newly developed method, and the results by the above-mentioned method are compared with the experimental results. The main conclusions are as follows: (1) The strength design method is developed where the connecting rod joint is modeled to the single-bolted joint. (2) The experiments concerning the stress on the connecting rod bolts are performed, and the analytical results by the above-mentioned method show a good agreement with the experimental results.

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In this work, proximity effects were clarified by exposing fine patterns to PMMA (0.5 μm) and FBM (0.5 μm ) on a chrome mask substrate with EB-52 (accelerate voltage 20 kV) and a double parabola model of exposed intensity was proposed. The results obtained are as follow. (1) Intro-proximity effects begin to appear on the 4 μm wide line pattern and 8 μm square pattern. These results indicate that the back scattering has extened in a 4 μm area around the beam center. (2) Inter-proximity effects begin to appear when the gap between the patterns is 3 μm and abruptly increase when the gap decrease to 1 μm or less. These effects significantly appear on fine patterns adjacent to large patterns. (3) Proximity effects of FBM, in which electronbeam sensitivity is one hundred times higher than that of PMMA, appear 20% stronger than that of PMMA. (4) The calculations from the double parabola model for a single scanning beam are in close agreement with experimental results.

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Two types of hydrostatic lead screws, designed aiming at easier manufacture and higher statical stiffness, were manufactured on trial. In Type 1 the nut is constructed by four sector shaped pieces and four plates sandwiched in four spaces between the aforementioned pieces in order to form the four sector type recesses. In Type 2 the nut is a single block, but full area of screw surfaces are utilized as recesses by sealing at crests and roots of nut threads. Main results of theoretical calculation and experiments on the statical stiffness are as follows: (1) In Type 1, the experimental value of statical stiffness is 40 N/μm, the theoretically calculated value is 53 N/μm, and their ratio is 0.75, being regarded as improved against the case of the same type screws in the previous report. (2) In Type 2, the experimental value of statical stiffness is 15 N/μm, the theoretically calculated value is 86 N/μm, and their ratio is 0.17. The reason of this undesirable results of the experiment is considered mainly due to leakage of hydraulic oil through seals.

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This study of solidifying mechanism of polymeric powder in cold compaction molding, made consideration in light of dynamics based on the results of experiments and explained the mechanism of solidification visually and theoretically. (1) It was shown that the more the compacting pressure is, the more indistinct the boundaries between adjacent particles are made, the wider the fusion spots become, and the higher the strength of the cold compacted products become, and that the dynamically compacted products show markedly better fusion between adjacent particles and much higher strength than the statically compacted ones. (2) Furthermore, among compacting pressure P_c, tensile strength σ_B, and average density of products ρ, empirical formulae of σ_B=K₃(P_c)^n₃ and σ_B=K₄(ρ)^n₄ were obtained. (3) In various model experiments, the deforming behavior of particles involved in compaction was observed visually, and as a result, with particles crushed greatly in layer with the increase of compacting pressure, an empirical formula of R=a(P_c)^-n_R was obtained between the crushed particle ratio R and the compacting pressure P_c, while an empirical formula of T=b(P_c)^-n_T was obtained between the thickness of products T and the compacting pressure P_c. (4) Furthermore, it was found that in compaction molding on single punch, particles are crushed more on the punch side than on the die side, while they are evenly crushed generally in compaction molding on both side punch.

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This paper describes a new automatic calibration system for polygon mirrors. This system consists of the following four subsystems: (a) a precise rotary mechanism, (b) a rotary magnetic scale for angular standard, (c) a special photo-electric autocollimator which enables a dynamic measurement and (d) a mini-computer system which controls the compiling and handling of data. The basic principle of the system depends on the selfchecking-method, so that both the polygon mirror and the standard rotary scale are calibrated simultaneously. The system adopts a time-conversionmethod to detect slight angular difference with high resolution. By way of an example, a 12-sidedpolygon has been calibrated on the system. The results obtained are as follows: (1) The calibration can be done automatically in a short time without skill, excepting the manual operation of setting a polygon relatively for the magnetic scale. (2) 959% confidence interval of instrumental error calibrated on the system is within ±0.07 seconds of arc.

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To develop milling tools for high-rate machining of steels, prototype cutters with a special double-rake edge design using the SWC (Silver White Chip) cutting principle have been evaluated in milling tests of the low carbon steel SS 41 generally used for weldments and the SCM 440 chromium-molybdenum steel. Three kinds of indexabletype prototype cutters with ISO M 2 grade inserts have been tested: they are, so-called “type-U” facemilling cutter intended for rough machining of the low carbon steel, “type-S” face-milling cutter for medium carbon steels and alloy steels, and “typeSL” cutter for slot milling operation. Test results show that when proper cutting conditions are selected so as to form the built-up edge on the primary rake face, the cutting edge is free from the fragile chipping, and therefore the high-rate milling is possible. A double-rake edge of the prototype cutters is operated normally and attain tool life from 2 000 to 10 000 cuts per edge at the metal removal rate several times greater than that of a conventional cutter edge. Machining power required by the SWC cutters is reduced by 20 to 38% to that by the conventional cutter. It will be possible to design cutters for practical use based on those test results.

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Grinding mechanisms are theoretically analyzed when tolerably high amplitude of wheel vibration causes the wheel to knock the work once a revolution as usually seen in the snagging operation. Insisting the wheel on a given predetermined vertical feed rate pattern which is assumed for a practical motion of the wheel during knocking (grinding), grinding mechanism is represented such as configuration and area of the wheel-work contact, instantaneous metal removal rate, cumulative volume removed, undeformed chip sectional area, and grinding forces in one blow grinding process.Taking a set of reasonable numerical values, the analysis is examined and compared with that of no vibration taken account. The instantaneous metal removal rate per unit contact area is identical with the vertical feed rate. Undeformed chip sectional area and grinding force is uniformly distributed on the contact face. Larger mean undeformed chip sectional area than that of the analysis without vibration is resulted in fairly decreased power consumption per unit metal removal rate. Instantaneous equivalent stiffness of contact between wheel and work is estimated which is extremely higher than that of without vibration.

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It was found in the previous report that the elastic deformation of contact wheel performs a significant role in belt grinding. This paper deals with the effect on the wear process of coated abrasive belts. The contact-wheel surface grinding was carried out at a fixed infeed, and the changes of belt wear rate and surface topography with grinding time were investigated. Grinding force pulses from individual cutting edges were also observed in a fixed part on the belt surface. The force pulses were obtained by lengthwise grinding of a very narrow workpiece attached to a high-frequency dynamometer. Detail investigations of the change of them with time made clear the rise and fall process of the cutting edges. The results revealed that the wear property is influenced by the contact wheel hardness. With a harder contact wheel the change from old to new cutting edges is smooth and prosperous. On the contrary, too soft a contact wheel brings about flattening or dulling of cutting edges and accounts for the glazed appearance of abrasive belt.

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This paper describes a simple method to calculate orientation probabilities of works with a conical or cylindrical surface. Important factors to determine probabilities of orientation of rolling works are deceleration of rolling velocity of works and the shape of separatrixes for rolling motion of works. On the other hand, in automatic assembling systems, many works roll simultaneously on a plane of feeder. In such cases, the deceleration is uniformly with any contact surfaces of works. Therefore, probabilities of orientation are calculated by considerations for the shape of separatrixes with rolling motion and considerations for deceleration become useless. The conical surface is divided in equal n parts and the one of parts is considered a small trapezoid for large number of n. The plane of critical angles of the part is given also for a trapezoid. The plane of critical angles of conical surface is given by a fan-shaped plane which is formed by collection of those trapezoids. The plane for cylindrical or circular surfaces is given by a particular case of conical surface. Finally, results of this method are examined by experiments which are performed for some examples.

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