[in Japanese]

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The paper proposes a simple calculating method for the production efficiency of automatic assembling lines. Machine stoppages of the line are occurred by various troubles in workheads or stations or by interferences with troubles in adjacent workheads. It is an important design problem to decrease those interferences and improve the production efficiency of the line. To this end, in automatic assembling lines, an intermediate storage buffer is set between workheads or stations. In this paper, in order to make clearly the relation between the production efficiency and buffer volume, at first, the simple and fundamental line composed two workheads which are connected with an intermediate buffer is subjected for the fundamental element of lines. Then, a method to calculate the interrupted time of the element is shown by considerations for frequency of troubles with comparatively small probabilities. The production efficiency of the lines is analysed by the interrupted time of the element. At the end, some examples are calculated numerically and simulations are performed by a degital computer for examples. From those both results, it is shown that the method is valuable to estimate the production efficiency of automatic assemlbling lines.

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The automatic dimensioning problem is one of the difficult problems in CAD. This paper describes an approach to the problem. First, when CSG is given as geometry data, the geometric pattern is recognized and dimensions are extracted depending on the types of Primitives. Second, based on graph theory, the extracted dimensions are connected to each other under the constraint that related dimensions (such as size of Primitives) must not be missed. Third, to verify consistency of the obtained dimensions, graph theory is introduced again. Experiments are conducted by using TIPS-1 Solid Modeler. Proposed approach method was proved to be effective through the experiments.

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This paper deals with dynamics of electromagnetic actuators. Self-inductance of an actuator usually increases with the approach of the armature to the coil. Through consideration about electromagnetic to mechanical energy conversion in the system, the equations can be composed which describe the behavior of the armature. For the simulation on dynamics of an armature motion self-inductance of some electromagnets is measured with various fixed armature position. Induced pulling force is just the half quantity of the product of second power of driving current and self-inductance gradient in the direction of armature motion. This is verified by experiment. According to the step response of driving current and armature motion, their kinetic characteristics are cleared. When the load of the system has only inertia of the armature, equation of motion and equilibrium equation of driving circuit are described by seven parameters. Solutions of these equations, armature displacement and driving current, nearly coincided with experimental result. The curve which denotes the relation between self-inductance and armature position can be changed by a certain parameter. This parameter is important in that it affects kinetic characteristics of an armature. The larger it becomes, the smaller counter emf becomes and shorter working time does.

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In this paper, an experimental and theoretical investigation has been made for the forced vibration of one-degree-of-freedom with asymmetric nonlinear restoring force. Forced vibration of nonlinear air spring excited by motion of support point is taken up, and the characteristics of stationary solution for this system is analyzed by means of catastrophe theory. The validity of theoretical analysis is confirmed by the experiment using a diaphragm air spring. As a result, it is clarified that the characteristics of this system can be described by the cusp catastrophe model. This means that the jump phenomenon of amplitude for the displacement of mass or the relative displacement is controlled by the excitation angular frequency and the amplitude of excitation displacement of support point. In other words, the jump phenomenon (including hysteresis phenomenon) is explained by the bifurcation set, which shows the relationship between the excitation angular frequency and the amplitude of excitation displacement of support point.

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Linear displacement in the range of millimeter to nanometer is determined by measuring phase variation of a one-dimensional periodic pattern such as a Ronchi grating, moiré fringes, and interference fringes. Phase variation is precisely determined by sinusoidal fitting whose algorithm is the same as that of phase detection which is well-known in communication techniques. Hardware system is quite simple which consists of a linear image sensor, a general purpose microcomputer, and required peripheral interface circuits. Errors inherent in the method is discussed in detail. Phase errors experimentally obtained in a Ronchi grating, moiré fringes, and interference fringes are 0.029 rad, 0.057 rad, and 0.068 rad, respectively.

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This serial study aims to develope the designing system of profile shifted involute gears and also a simple, effective optimization technique (influence index number method) that can be applied to particularly complex programming required for such a design of gears. This paper deals with the internal gear having the same number of teeth as a pinion, constituting a special internal gear-set which is engaged at an appropriate center distance to be used as a substitute for an Oldham's coupling. Because of involvement of coefficient of tangential profile shift in addition to a number of specific interference, designing variables exert complicated influences on the designing of this gear. Therefore, an effective, computerized system is required for designing of such special internal gears. The system and technique developed are fully tested by extensive actual design computation and trial manufacture of an example of gears designed by the present method. The test confirms that this designing system and simple technique are also very effective for designing of internal gears having no difference in number of teeth.

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This paper presents the holography interferometry using a special operation when the hologram is recorded. The interference fringes are given space modulation, and the small deformation of an object is measured by demodulation of the modulated fringes. The demodulation fringes show the contour mapping of the deformation. The demodulation method is used the moiré method or the multiplication method.

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In this paper the fundamental investigations are performed to apply the Caustics experimental method to the measuring of stresses at the cutting edge during metal cutting operation. The method is considered to be very useful to solve the problems with stress concentration or stress singularities. The object of study is the two dimensional half-plane loaded perpendicularly or obliquely with the concentrated or uniformly distributed force. Specimens are made of polymethyl-methacrylate-resin and as a light source He-Ne gas laser is adopted. The interference Caustics patterns made by the reflected light rays from the front and rear surface of the plate under various loading conditions are observed and those characteristics with the intensity, distributed width and inclined angle of external load and the other factors determined from the optical arrangement are investigated in detail. On the other hand the computational patterns are plotted based on the optical theory. These two patterns are coincided accurately enough. Therefore clarifying the relationships between the pattern form and size and the above mentioned factors by the experiments under various typical conditions, general unknown loading conditions will be made clear and stresses and strains will be able to be obtained.

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This paper describes the analytical condition for modification of the work roundness error and its confirmation by experiment in cylindrical magneticabrasive finishing using magnetic-abrasives. The analytical and experimental results point out that the magnetic-abrasive finishing process has the improving ability of the work roundness error.

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This paper describes a method for obtaining stress-strain characteristics of rigid PVC resin under such conditions that are encountered in a deformation zone of that cutting. For this purpose, the impact-compression testing machine is employed, which includes a special stopring which enables to control strain increments during each impacts. The experiments are carried out under strain range 0-0.7, strain-rate range 10^-3-10³ s^-1 and temperature range 0-120°C for rigid PVC resin. The main results of these experiments are summarized as follows: (1) Flow stress of PVC is not influenced by the strain rate history and temperature history. (2) The flow stress of rigid PVC resin may be expressed as
σ=σ₀(ε/ε₀)^m(ε/ε₀)ⁿ exp(-αθ)
where ε, ε and θ are total strain, total strain rate and temperature, respectively. ε₀, ε₀ and σ₀ are referenced values of strain, strain rate and stress, respectively. m, n and α are constants at temperature less than 80°C, but they change at temperature higher than 80°C. (3) The relationship between plastic strain ε_p and total strain ε on rigid PVC resin is expressed as
ε_p = 0.89ε-0.07.

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An attempt was made to break chip produced from NC lathing by intermittently decelerating the finish turning feed. A personal computer was used to make a part program involving the intermittently decelerated feed. As a result, it was found that the chip is broken into easily disposable smaller pieces by optimizing the interval and the rate of feed deceleration for a material cut. Also it was observed that the surface roughness is slightly improved.

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In screw thread turning, the effects of cutting methods and cutting conditions on cutting forces and cutting force ratio (ratio of radial force to tangential force), the variations of cutting forces and cutting force ratio with tool wear and failure are investigated experimentally. The following phenomena are clarified. (1) Feed force varies with cutting methods, it becomes positive values in flank infeed and negative values in radial infeed. (2) Cutting forces vary with cutting methods and cutting conditions. Cutting force ratio is effected only by depth of cut and cutting area. (3) Tool failure makes radial force and cutting force ratio increase sharply. (4) The progress of tool wear differs with cutting methods, and groove wear which copes with the number of pass arises on flank. (5) Cutting forces and cutting force ratio increase with tool wear, and the detecting sensitivity of flank wear by means of cutting force ratio is about 0.025mm/%.

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The low machinability of difficult-to-machine materials is essentially attributed to their particular material properties, which are also responsible for the peculiar chip formation such as serrated chip. Then based upon the flow stress characteristic reported in the previous paper and the thermal properties, the stress, strain, strain rate and temperature distributions in machining of a titanium alloy and a nickel base superalloy were obtained using the visioplasticity technique and the finite difference method. The analysis in the titanium alloy reveals that the thermal instability which first appears along the rake face plays the major role for the serrated chip formation, while the instability in the primary shear zone is merely associated with the shear fracture due to the own brittleness of this alloy. It is further concluded that chatter vibration and very small tool-chip contact area are often induced by the inevitable serrated chip formation in this alloy, and excessive tool wear is resulted from extraordinary high temperature at the cutting edge due to the intensive strain concentration on the contact area. For the nickel base superalloy examined, it is made clear that since its flow stress and the normal and frictional stresses on the rake face are extremely high compared with plain carbon steels, the tool temperature is so high that the tool wear will be severe. The intensively strainhardened surface banished by the worn tool would cause the chatter vibration, which is also harmful to tool wear.

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This paper presents the method for estimating the most suitable grinding conditions of surface finish for decoration against the grinding time of platen type abrasive belt. The time dependent characteristics of the ground surface roughness R_a and R_q are investigated experimentally from 1s to 1800s. The experiments were carried out under on a 3³-factorial design whose independent parameters are grain size number (#80, #150, #240), grinding speed (480m/min, 960m/min, 1440m/min), contact pressure (17kPa, 35kPa, 50kPa) for the hard steel (S45C). The 2nd order model with over 88% of the coefficient of determination was obtained by the multiple regression analysis. The simplex method was applied to analyse a response surface of the model in order to obtain the maximum point which presents the most suitable grinding conditions. The analytical results indicate that the larger the contact pressure, the lower the grinding speed against the grinding time. They are also confirmed by the computed perspective view of three-dimensional belt sanded surface.

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In this paper, the relationship between the roundness of a center and that of a machined workpiece in center-type cylindrical grinding is investigated by using Fourier analysis technique. The obtained main results are as follows: (1) Commercially available centers have predominant two-lobe component in their roundness error. (2) When a center having comparatively superior roundness is used, the out-of-roundness value of the workpiece depends mainly upon the two-lobe component of its profile. When an inferior center is used, the out-of-roundness value of the workpiece depends upon both of the two-and three-lobe components of its profile. (3) When the minor axis of the two-lobe component of the center is set vertically, the two-lobe component of the workpiece becomes large and the three-lobe component becomes small, compared with the other orientation of the center.

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