[in Japanese]

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This paper presents the quantitative relationship between one's visual estimation and the analytical data of the high quality surface texture. The quality of belt sanded surface is investigated systematically by 50 panelers. The test pieces are ground under the various grinding conditions using the platen type belt grinder. The results of factor analysis point out clearly that there are strong relationships between high quality and the properties of surface geometry based on the correlation diagram. The physical meaning of high quality estimation are explained by the range of (1) mean curvature, (2) mean slope of asperity, (3) optical characteristic roughness S_N, (4) center-line average height R_a, (5) the number of peaks, and (6) the number of zero-crossings, respectively. It was found that the irregularity of long crestedness perpendicular to grinding direction can be estimated by ARMA (4, 3) model of S_N due to 0.2 mm beam.

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The activity is defined by impulse acted to compress a work. It is effective to hold down reducing the activity that the anvil ratio is taken as large as possible. And the practical mass of the work is permitted an amount about equal to that of a hammer, because the effective mass of the work decreases less than half as much as the practical mass. This property is one of the merits of this method, the work is held by an operator's hands guided on the work table. The force level is estimated by an rms-value to get a reduction effect of the force high enough for design of the improved machine. The level at the anvil is proposed to an accumulation of impulse per unit time. The reduction effect is proposed to a square root of collision time, so that this method is more valuable for the stronger impact. It has the only one weak point, the effect decreases for growth of the hammer's motional amplitude near by resonance of the hammer system. But the defect can be overcome by improvement of the system. Finally, the design method is established according to the optimum impact conditions.

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This paper aims to realize a control system on feed for chip treatment. In case of turning operation, stability of chip breaking which is undertaken by chip breaker is affected by cutting condition (feed, cutting speed, etc.). As information about chip treatment or vibration of workpiece are included in fluctuating component of tool-work thermo-electromotive force (E. M. F.), relation between states of chip treatment and average value of periodic ratio or frequency of fluctuating component of E. M. F. has been studied. For this study, measurement and feed control system which is composed of microcomputer was made especially and adaptive control on feed based on results of cutting experiment was examined. Results obtained are as follows. Average value of periodic ratio of E. M. F. presents minimum value in accordance with chip treatment in which form and length of chips are uniform. Frequency of chip breaking increases following to increase of feed and it reaches to constant value. It is possible to maintain chip treatment in the range of good condition by controlling feed automatically.

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We attempt to make an actuator with a wide range of speed ratios by mechanically combining conventional actuators. It is called the differential actuator. We report the characteristics of the differential actuator constructed with various conventionally used actuators i. e. DC motors, AC motors and stepping motors. As a results of experimental and theoretical considerations, it was found that the new actuator with an extremely wide range of speed ratios from speed zero to maximum speeds of unit actuators could be realized.

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In order to automate tool management, which is a serious problem in a flexible manufacturing system, a cutting tool equipped with a sensor to detect flank wear and tool failure was developed. The sensor is a resistance film circuit formed from titanium on the flanks of a throw away alumina tip. The sensor is located in a position parallel with the cutting edge. The means of detecting wear of the tool is through measuring electrical resistance. The electrical resistance of the sensor gradually increases as the resistance film circuit is worn off by flank wear and the circuit becomes narrower. Therefore flank wear can be directly detected by measuring the electrical resistance of the sensor. In the experimental results, close agreement between measured and calculated values was obtained, and it was clear that flank wear could be detected by measuring the electrical resistance of the sensor after each use.

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In this paper, a new and simple turning-surface root-mean-square-roughness(RMS) measuring method by Fraunhofer diffraction of a slit aperture is investigated. A He-Ne laser parallel beam illuminates a slit aperture formed between a test object and a reference knife edge. The absolute value of RMS is obtained by the zeroth order Fraunhofer diffraction light intensity as a function of the slit aperture width. This measurement method is characterized by non-destructive technique and obtaining the absolute RMS value of a surface profile. The experi-mental error caused by the slit aperture width and the laser beam output fluctuation is discussed by a numerical anlysis of a periodical-surface profile model. Measurements are carried out several turning-surfaces. The typical turning-surface RMS values by employing this method are compared with the calculated values of experimental results using a stylus instrument and the previous surface profile measurement method, and the RMS values of three experimental methods almost agree.

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This paper describes the mechanical structure of a friction drive system and its traction characteristic. The system consists of a DC servomotor, a friction reduction device (planetary roller type) and a friction drive elements (a pinion roller and a slider). The linear scale measures the slider displacement, which is fed back to the servomotor by way of a micro computer. Since the friction drive system is mechanically easy to make and has small non-linear factors, it is thought that this system is good for precision positioning. In case of usual friction drive, a traction characteristic is easily obtained by measuring the torques of two friction wheels, but in this study it is very hard to obtain it because the slider moves longitudinally. Therefore, the traction characteristic is obtained by a frequency response method between two velocities of the pinion roller and the slider. It is shown that the traction between the pinion roller and the slider is estimated by using an exponential function of the slip ratio.

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It is known that the stronger restricting effect can bring the higher stiffness for the applied aerostatic bearings. So called “the surface restriction” is preferred instead of such conventional ones as an annular orifice from the above point of view. The analyzing method for the surface restricted aerostatic slideway, adopted Finite Element Method for instance, may result in an exact solution, but be rather complicated, hence not suited to be applied for the practical design stage. The present paper stresses the easiness of calculation for bearing performances, and has developed the simplified analysis, where the continuous air flow is replaced by a lumped constant model. That is, the bearing surface is meshed into nodes, and the pressure at a certain node is equated by the surrounding four nodes. Linking each node and taking balance as to the whole bearing surface, the simultaneous equations with the unknowns of number of nodes can give the pressure distribution, bearing capacity and stiffness. Some experiments, made for the different sizes of “T”-shape surface restrictor, could considerably well coincide with the analysis, and could show that the present analysis was quite practical to design the required specifications.

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A novel high precise quantitative measuring method of the refractive index by appling the fringe scanning and the scanning moiré methods to moiré deflectometry is described. Since the proposed setup is founded on the shadowgraph apparatus, this system can be manipulated simpler than the interferometer. Then the automatic measurements can be performed by microcomputer. When this method is applied to the measurement of the fast air flow in the Laval nozzle, it is confirmed that close agreement between measured results and theoretical values is obtained. Furthermore the pressure mapping in the nozzle can be measured by assuming the relationship of the adiabatic change. These results show that this method is useful in the fields of flow visualization.

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Recently, gas bearings have been used in high technology industry. By the use of pocketed orifice restrictors, the stiffness of the bearings is greater than that of inherently compensated bearings and the highest value is obtained at 10 μm (0.1 mm in orifice diameter) in mean radial clearance. But in these bearings, the pocket volume exists in the bearing surface, therefore it is possible that damping coefficients get to minus sign. In this paper, damping coefficients are measured when a sinusoidal force and an impact force act to the shaft, and theoretical calculations and experimental results are compared. Following conclusions are obtained : (1) Damping coefficients are affected by the pocket depth, eccentricity ratio and orifice diameter, but this bearing system is always stable under the condition that nondimensional pocket depth N is less than 3-8. (2) When the sinusoidal vibration is given, stiffness and damping coefficients are beginning to vary in σ> 0.5.

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This paper describes the loading of soft grade wheel and effects of removal of loading chips on grinding performance. In creep feed grinding, chips are long, thin and curled. The chips loaded into wheel pores, therefore, are not removed easily, and are remained. Such loading chips have adversely effects upon the grinding performance. Soft grade wheel which is effective to prevent dulling has large pores, so that it seems that the wheel is effective to prevent loading, too. In this paper, loaded area rate which is the ratio of loaded area to wheel surface area is measured by reflected light intensity method in creep feed grinding with the soft grade wheel, and influence of wheel depth of cut and wheel grade on loaded area rate is clarified. For the improvement of grinding performance, furthermore, loading chips are removed with high pressure grinding fluid supply unit and specially-made nozzle. As a result of investigation, the followings became evident. (1) Loaded area rate increases with a rise in wheel depth of cut or wheel grade. (2) In the case of the soft grade wheel, removal of loading chips is effective in reducing a wheel wear, but is not effective in reducing a grinding force.

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Prior to the simulation, the edge fracture test of “A” type single grain was conducted and the fracture characteristics obtained were compared with those of “WA” type grain reported in the previous paper. The fracture onset probability is small for “A” grain regardless of edge shape, while it is large for “WA” grain except the flat type edge. Transition probability p₉₉ that the flat type edge changes again to the same one after fracture, is quite small for “A” grain in contrast with the value of almost unity for “WA” grain. Next, simulation analysis of the sequence of edge fracture and edge shape transition during surface grinding, in which grain depth of cut varies with time and location, was carried out with Monte Carlo method. Since the fracture onset and the edge shape transition have Markov property, they were determined independently of their history by generating random numbers in accordance with the probability distributions of the onset and the transition. In the analysis, the height loss of grain tip was also taken into account. For “WA” wheel, it is found that the grain depth of cut is reversely proportional to the fracture onset probability, hence the flat type edge exists in the outer layer of the wheel and contributes to the stock removal greatly. On the other hand, the edge sharpness is kept up for “A” wheel since the flat type edge often changes to other sharp edges due to the small p₉₉.

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In the first part of this investigation a model of oblique cutting, in which boundary of the chip and workpiece in the plane normal to the cutting edge is constructed by two circular arcs and the condition of up-curl of the chip is satisfied, was developed. The cutting model enables to predict the chip formation and the cutting forces by specifying the tool-chip contact length and frictional condition on the tool face. In this paper three components of the cutting force and the chip formation such as chip flow angle, normal shear angle and radius of up-curl of the chip are measured and compared with those predictions. Most of the predicted results agree well with the measured results. On the radius of up-curl of the chip predicted and measured values are in good agreement in the range of large inclination angles.

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The skilled machinists evaluate precisely the sharpness of cutting edges by weighing the perceived grinding sound on their scales acquired through the experiences. The purpose of the present paper is to make a suggestion regarding the sharpness evaluation by the model using the fuzzy integral. The constructed model gives the values of sharpness grade by weighing the loudness of the various bands of frequencies on the fuzzy measure which the machinist's subjective characteristics in grading the redress life are identified. From verifying results of the model, it was found that the outputs of the model agreed approximately with the machinist's evaluations and the model became a very useful method for the in-process measurement.

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This paper describes a new internal finishing process of a non-ferromagnetic tubing by magnetic abrasive machining and its finishing characteristics, in which the suitable concentrative magnetic field is performed in the inner working region of a tubing by N-S magnetic poles settled in the outer side so that the magnetic force as finishing pressure acts upon magnetic abrasive particles to the internal surface. From the experimental results, it is found that 4 μmR_max in surface roughness of a stainless steel sanitary tubing (SUS 304, 38.1 mm in outer dia., 1.2 mm in thickness and 200 mm in length) is improved to 0.1 μmR_max in 10 minutes finishing time.

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An automatic grinding system for curved surfaces with a six-axis force sensor has been developed. This system finishes the curved surface of a die, etc. by detecting the grinding force acting on the tool such as a mounted wheel with the sensor and controlling it adaptively by a micro-computer. The six-axis force sensor has been developed specially for this system. It has a compound structure composed of parallel and radial plates, and it can detect three components of the force and three components of the moments at the tool point. It has been shown that this system can be useful for not only grinding the curved surface of a die, but also finishing the surface of castings and beads of welding.

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This paper describes the influences of nitrogen-ion-implanted drill surfaces and the time of nitrogen-ion-implantation on the cutting characteristics of drills. Experiments were performed by making blind holes. In ion-implanted drills, cutting edge corners sometimes drop due to the deep groove wear on margins, which leads to the drill breakage. On the other hand, in non-implantation drills, corners do not easily drop, since they have shallow and wide wear land on margins. From the viewpoint of tool failure, the ion-implantation on flute surfaces, i. e., rake faces, is most effective. With respect to hole accuracies, e. g., finished diameter, roundness and roughness, the ion-implantation on margins gives the best quality.

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