The objective of the present paper is to clarify the heat partition ratio in spindle units with aerostatic bearings. Heat generated in the journal bearing clearance is transferred to the spindle, bush/housing and exhaust air. In order to develop the thermal model on the basis of experimental evidences, a test machine was used running to a maximum rotational speed of 20000 min^-1 with a 60 mm diameter spindle supported by aerostatic journal bearings of 20 μm radial clearance, and the temperatures were measured of the housing, bush and the interface between the bush and air film as well as the inlet and outlet air. A finite element model has been developed to evaluate the partition ratio. The analysis shows that the ratios of the heat flowing into the spindle, into the bush and into the exhaust air to the generated heat are about 1/3 respectively in the test air spindle unit, and that increasing the bearing clearance is most effective to reduce the air film temperature.

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This paper describes a high-power electrostatic film actuator that consists of double-sided drive type films. There have been several reports on electrostatic actuators that utilize stacks of electrode films. However, in those actuators, the electrode films can generate strong electric field only on the front faces of the films, and thus, thrust force can be generated only when front faces are opposed. In this paper, a new structure for the electrode film, in which strong electric field can be generated on both faces of the films is reported. It was verified with fabricated prototype films that a pair of new structure films can generate thrust force even when their back faces are opposed. A thin linear actuator with twenty-one films is fabricated, and its output power and efficiency are investigated. The actuator generated power over 3.5W when applied voltage was 1.4kV_0-p. Maximum efficiency was measured to be 46%.

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Care lift is one of welfare machines. Most care lifts with power assistance lift up a handicapped person who has a disability in his legs like an industrial crane by applying the power of motor. However some care lifts bring the undesirable shock to a handicapped person because of the high-tension in its lift up motion. So the speed of lift up motion must be adjusted to decrease the power of shock. In this study, the method that can reduce the power of shock is proposed. It is suggested that the compliance control involved in the power assistance system of care lift can reduce the power of shock for the handicapped person at the moment of being raised.

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This paper introduces a micro thermocouple array to measure resin temperatures and heat flux through resin in an injection mold. φ25μm alumel and chromel wires were welded by laser and assembled to integrate a micro thermocouple array with three measurement points on 0.5mm pitch. The micro thermocouple array was set inside the cavity of the injection mold, and the resin temperature was directly measured. The measurement result showed the resin temperature was 10 °C higher than the nozzle temperature while the resin passed the gate. Then the heat fluxes between each measurement points were calculated from resin temperatures measured at the three measurement points, and it was found that the maximum heat flux was about 2.3W/cm².

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Gear tooth with the highest accuracy is graded on the order of 0.1 μm by ISO 1328-1, however gear measuring instruments have normally 1-2 μm measurement uncertainty caused by moving components such as guide ways, rotary table, or electronic components, software and so on. These uncertainties of measurement are usually estimated by calibrated gear artifacts, though the best achievable uncertainty in gear measurements may be 20-30 %.
In view of this situation, AIST (National Institute of Advanced Industrial Science and Technology) has proposed a new calibration method using ball artifact consisting of two master balls (DBA). Difference of the distance between the arc of the master ball and involute curve can be calculated theoretically. For the calculation, center distance between two balls and ball radius are required and the value is very important and also should be traceable to national standard of length.
This paper reports on a new method and an originally developed instrument to measure the center distance between two balls by using laser interferometer. The expanded uncertainty in measurement of a center distance of 44 mm is 21 nm.

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This paper proposes a method to search a target image area that has an arbitrary location and inclination to a registered template image in an objective gray-scaled image. The gradation area vectors that indicate locations of regions with reduced gradations in a circular image area are used for matching. The relations between the gradation area vectors are invariant not only to a movement but also to a rotation of a circular image pattern. A target image area can be searched by measuring a correlation of inner products between a template image and a circular image area. The experimental results show that the target image area with arbitrary locations and inclinations were searched successfully by the proposed method.

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The measurement of machining accuracy on machine tools is always problem in light of efficiency. Also the measurement in three dimensions is problem in terms of the so called “lead time” in the manufacturing process. We propose our new approach that could precisely measure machining accuracy in a limited time through an image-processing by a CCD camera installed in a machine tool on constantly changing texture patterns, which are created by ball-end milling. This paper has led to develop hands-on measurement of machining accuracy verifying the usefulness and reliability by simulation of machining accuracy and actual measurement process.

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This paper describes a three-dimensional coordinate comparator using a reference workpiece with the same material and geometrical profile as the measuring workpieces. Because of little influence of the temperature change, this measuring machine can be utilized in shop-floor thermal environment instead of a conventional coordinate measuring machine which measures absolute coordinate values. Moreover, the comparator's geometrical deviation and the probe's error have little effect on the measured values. Measurement results using gauge blocks, and optical flat and workpieces with complicated profile show that this comparator has measurement uncertainty less than ±1 μm regardless of temperature change of several degrees.

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This paper proposes the high-speed and high-precision position control for industrial machines and semiconductor products using predictive velocity method. In order to achieve high-speed and high-precision response, the high gain feedback is ordinary method. With the high gain parameters, the delay of detection of position signal may cause some machine vibration. Therefore, the detection delay has to be compensated to get high gains. In the proposed method, the phase of predictive velocity signal is forwarded and the predictive velocity signal maintains good accuracy, since the predictive velocity signal is calculated with position signal, torque reference and the dynamics model of the machine. This method is easily adapted to P, I-P controller. The proposed method was verified by the simulations and the experiment results with one axis slider with the high gain feedback parameters. Moreover, the position reference response and the position disturbance response were greatly improved by using this method.

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In our earlier report, the results demonstrated that the addition of mechanical stimulation by artificial wind and vibration was related to an increase in the amount of moisture transported in the plant. The increased amount of moisture transported in the plant will activate photosynthesis and increase the absorption of nutrients from the roots. Based on those earlier results, the present study entailed providing artificial wind via mechanical stimuli to the Komatsuna plant (botanical name : Brassica campestris) and examining the relationship between the amount of growth (leaves area and total weight) and the photosynthetic rate in this plant. We used 1, 10, 30, 60 and 120 minutes as wind periods, with an artificial wind of 0.5 m/s. For example, a 30-minute wind period consisted of 15 minutes of wind time and 15 minutes of windless time. As a result, we confirmed that both the photosynthetic rate and the amount of growth with artificial wind during the 30-minute wind period increased compared to the windless case. This result was qualitatively proved by the simulation of photosynthetic rate using the electrical circuit model.

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The detection of micro cracks generated on the machined surface is very important, because it affects greatly the strength and fatigue life of products. In this paper, a new crack detecting method by using reactive ion etching for brittle material such as monocrystalline silicon, crystal and fine ceramics has been proposed. The effect of etching condition on the crack detection for monocrystalline silicon was experimentally investigated. The experimental analysis made it clear that the anisotropic etching is predominant under low etchant gas pressure condition for brittle material. Therefore we can detect the cracks more clearly using this method compared to the conventional wet etching.

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Two-dimensional axisymmetric non-steady heat conduction was analyzed considering the laser diffraction in the image formation optical system and resinous evaporation. The validity of analysis was confirmed comparing with the experimental results. Main results obtained are as follows : (1) When the resin is relatively thick, the shape of via hole reflects the laser intensity distribution because the thermal conductivity of resin is not so large. (2) As the thickness of remained resin becomes thinner than the absorption length of resin by repetitive irradiation, the removal quantity rapidly decreases and the smear remains on the substrate. (3) Less the removal quantity, less the reflection of the laser intensity distribution to the bottom shape of via hole although the side angle of via hole hardly changes. (4) Two- or three-dimensional non-steady heat conduction analysis considering the diffraction of the optical system is necessary for estimating the shape of via hole. (5) The one-dimensional analysis proposed in the previous paper is useful enough to estimate the removal depth although the removal depth by the second shot would be a little deeper than expected because heat is transferred in the radial direction.

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This research aims to clarify the cutting phenomenon at the high-speed interrupted cutting while paying attention to the cutting temperature. Carbon steel S45C was machined in the face milling within the range in cutting speed 269-2089m/min. The cutting temperatures and the tool wear characteristics, when the high-speed interrupted cutting was done, were investigated from the viewpoints of the cutting speed and the real cutting time in one rotation. The cutting temperature was measured by using the tool-work thermocouple method. As the results, in low cutting speed, the wear progress rate of the interrupted cutting was higher than that of the continuous cutting, but the wear progress rate of the interrupted cutting lowered oppositely in the high cutting speed range. And, the cutting temperature had the maximum peak at a certain cutting speed for the increase of the cutting speed under the cutting condition that the cutting time shortened very much, and the maximum peak shifted to the low cutting speed side as the width of the work material became small. It was understood that there was a possibility of decreasing the cutting temperature in high-speed interrupted cutting.

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In a conventional method for machining sculptured surfaces, cutter location data that is generated from a master model or a surface model is input into a numerical controller. Since the data lacks the information of the original model in any case, there is a limitation to obtain a fine finished surface essentially. To overcome the limitation, we have proposed a numerical control with surface driven interpolation. The numerical control generates servo data by interpolating sculptured surfaces directly. However, the prototype system has a problem that some slight scratches are found on a finished surface. To resolve the problem, this paper proposes a distance estimation method using a digitized model and an acceleration compensation that adjusts acceleration within a tolerance. The experimental result compared with a commercial CAM system shows that the proposed numerical control provides a fine finish and reduces the scratches.

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In previous paper, cleaning and removal functions of a waterjet were examined and the effect was validated as a means of inprocess dressing. This paper discribes : a) the optimal injection pressure of a waterjet dresser depending on the grain size of the wheel and b) the dressing effect of a waterjet dresser in relation to its injection angle in grinding Ti6Al4V using a cBN wheel. The optimal injection pressure of a dresser differed depending on the grain size of the wheel, and the condition of a processed surface deteriorated when the injection pressures were not optimized in the in-process dressing with waterjet. It was clarified that higher waterjet pressure was required to remove chips as the grain size of a wheel became smaller in the dressing using wheels of a grain size from #230 to #1000. The collision speed of a waterjet with a wheel differed depending on the injection angle. When a waterjet collided with a wheel in a direction opposite to its rotation, the collision speed became higher and a better dressing result was obtained. Conversely, when a waterjet collided with a wheel in the same direction as its rotation, the dressing effect decreased. It became clear that the injection angle of a waterjet has considerable influence on the dressing effect.

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