A parallelly-actuated mechanism has a disadvantage of having a smaller workspace than a serial mechanism. It is important to get a larger workspace in order to expand its application field. The workspace of the parallel mechanism depends on the swing angle of the ball joints used in the mechanism. If the housing of the ball joint is milled close to the equator of the ball to achieve a large swing angle, the ball may leave the housing during the motion. This paper presents a new method for making a ball joint using epoxy-type bond that enables a large swing angle and precise motion without any special techniques. It realizes a comparatively cheaper and simpler way of making the ball joint. This approach can be applied to assembling precise parts with small clearances that are difficult to machine. This paper also describes the ball joints performance characteristics and the coating process of the release-agent to achieve precise clearance. A clearance of approximately ±0.015mm on the new ball joints was achieved.

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While the light excitation substance such as a high polymer absorbs the light energy of ultraviolet ray, it will be in excitation. If its substance reacts with the processing material in an atomic order under excited conditions, that reaction may be available for a fine processing. Thus, it seems that the processing in a sub-nanometer order may be realized by the phenomenon that is called the luminescence. The following merits can be considered; 1. Little reaction heat. 2. Little heat influence to a processing material. 3. Easy and clean reaction control in comparison with the chemical processing. In this research, the processing principle was deduced and partially verified by dipping a copper for a fixed time in a mixed liquid of the fluorescent substance that glared by ultraviolet ray. The surface of copper that was precisely lapped is used for an experiment. The chemical etching of copper surface was observed by AFM. This paper describes the processing characteristics of copper which ultraviolet ray was exposed on. The irradiation of ultraviolet ray increased the corrosion rate of copper, and the surface roughness becomes small. The irradiation by ultraviolet ray improves the surface roughness over all condenses of processing liquid. The minimum surface roughness was obtained at the appropriate irradiate time, pH, and the height of liquid level. The temperature arise of liquid decreases the surface roughness of copper.

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To manufacture the highly functional micro devices by hot embossing, polypropylene (pp)/vapor grown carbon nanofiber (VGCF) composite film with orientated VGCF in matrix by rolling and extrusion methods were developed. Furthermore, mechanical properties, thermal properties and volume resistivity of nano-composite film were investigated. In composite film reinforced with 30wt% VGCF and rolled to 80%, high tensile strength equivalent to an engineering plastic (PEEK) were achieved. This was due to the increasing VGCF content, the existence of orientated VGCF and decreasing of defects which exist on surface of composite film and at the interface between VGCF and pp matrix. Also, volume resistivity was decreased with increasing of VGCF content. And the storage modulus was increased by the increasing VGCF content.

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The form error, which is generated by the ultra-precision machine tool with laser interferometer, is due primarily to the measurement error caused by the change in laser wavelength that is affected by the refractive index of the air, which depends on its temperature, humidity and pressure. This paper describes a new wavelength tracking compensator that can continuously update the precise refractive index and the performance of its application to the machine tool. This compensator is made up of environmental sensors mounted on the machine tool, a PC based analyzer and a compensation board added to the interferometer processor. The analyzer calculates the refractive index using Edlen's formula from atmospheric temperature, humidity and pressure measured by the sensors. The compensation board, which corrects the measurement wavelength using the obtained refractive index, provides the accurate position update for the CNC controller. The compensator can also correct the error of deadpath length in optical path as well as that of refractive index. The measurements of the displacement of the tool relative to a workpiece and of the form error performed by raster flycutting are executed to evaluate the performance of the compensator. Both measurements that imply the highly corrected accuracy of less than 100nm show a remarkable improvement compared with the case without compensator.

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Dies for injection molding parts such as cellular phones and light conductive parts require a high quality surface finish in terms of both appearance and integrity. Manual finishing is an important die manufacturing process, which decides the surface roughness of a die and influence the accuracy of its shape. However, manual polishing consumes several days to finish the die surface. Therefore, high precision die milling or grinding are required that improve surface roughness, in order to minimize polishing operation. In the previous report, ultrasonically diamond grinding experiments were carried out to confirm ultrasonically oscillation effect for die steel face grinding. And mirror surface was obtained. However, tool form error and run-out prevent 3D form mirror grinding. Because high shape accuracy tools are essential for high precision 3D form grinding. This paper provides results of toolmaking and performances of electroplated tools in ultrasonically assisted grinding. Electroplated tools can perform ultrasonically assisted face grinding and ground surface has roughness 0.24μmRz.

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Recently, linear ball guideway is often used for precision and ultra-precision positioning. As the linear ball guideway has rolling frictional characteristic, it is very difficult problem to achieve precision and ultra-precision positioning. Nonlinear spring behavior indicating the relationship between applied force and displacement, characteristic indicating the relationship between applied force and velocity and circular contouring error at quadrant changes are simulated by using the bristle model proposed for expressing sliding frictional characteristic when full-closed loop control is used. Precision positioning apparatus of an axis using a voice coil motor (VCM) is composed for measuring their characteristics. The simulated and measured results are compared. As a result, the simulated results using the bristle model are agreed with measured ones in both nonlinear spring and rolling area using two spring constants properly. In this study, a method of making the spring constant functions is proposed for not choosing spring constants.

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Although vacuum arc deposition can deposit amorphous carbon (a-C) film at high growth rates, the problem is that it leads numerous droplets than other PVD. Proposed methods for decreasing droplets, such as shield plate and magnetic filter, can actually decrease droplets, however they reduce growth rate. This study focuses on deposition of a-C films by vacuum arc deposition to achieve both higher growth rates and homogeneity of a-C films by decreasing droplets. It is necessary to control the vaporizing process of solid carbon target by improving discharge conditions for both higher growth rates and fewer droplets. Deposition of a-C film with low density of droplets at high growth rates was attempted by optimizing discharge voltage, electric charge and the structure of arc discharge unit. The optimized conditions, such as higher discharge voltages, larger electric charges and shorter distances between cathode spot and anode edge, decreased the number density of droplets per film thickness. The a-C film deposited under the optimized condition had the number density of droplets of 4.2/mm²·nm at the growth rate of 3.5 nm/count. XPS analysis showed that deposited a-C films had sp³ ratio of about 80%, therefore its density was estimated to be approximately 3.0g/cm³.

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In order to achieve assembly by using robots, we need a deeper understanding of the tasks. However, it is difficult to analyze complicated assembly tasks by geometrically or statistically based methods. In this paper, we analyze clutch assembly using a dynamic simulator in order to gain such understanding. We especially investigate the qualitative relationship between task efficiency and a search motion for engaging a spline gear with movable clutch plates. Our results indicate the existence of an appropriate search speed that can achieve the tasks efficiently.

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Market trends are rapidly changing, and timely decisions are becoming more crucial and difficult than ever for manufacturing industries. We proposed a manufacturing system named Square-Arrayed Machining Cell System (SAMS) as a feasible and promising system towards this goal. SAMS is aimed to have an autonomous layout ability, which does not need a specific or absolute outside signal indicating changes in the manufacturing circumstances to reconfigure itself. In this paper, we focus on the methodology to facilitate an autonomous layout function in its planning state that realises the specialization and generalization in SAMS, and propose a layout creation function for the SAMS. The characteristics and effectiveness of the proposed methodology are investigated by computer simulation using a model manufacturing system.

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Computer aided process planning has been expected to accomplish integration between design and its downstream, and has a role of a bridge between CAD and CAM applications. Since manufacturing feature recognized from CAD database is applied to communicate information in computer aided process planning, it becomes a key issue how to manage manufacturing features to achieve optimum process planning with minimum human intervention. For this purpose, an idea of a feature dependency of manufacturing feature based on a base plane is proposed. The feature dependency is a collection of manufacturing features based on the base plane in a hierarchy relationship. The base plane is a planar face which corresponds to a machine tool axis direction. Using this base plane and its feature dependency, each feature can be assigned to each specified process immediately and correctly, and all the successive process planning work is completed effectively. The systematic methodology for process planning, including unrecognized features, using feature dependency based on a base plane is presented, and the possibility of implementation applying this approach is verified by developed prototype CAPP system.

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Until now, output force distribution characteristics in human limbs have been discussed based on joint torque. Furthermore, a measurement method of joint torque was prescribed in detail, and measured value is shown as database to the public. However, in another precedent study, the relationship between output force distribution and muscular strength in human limbs was demonstrated under the theoretical back ground of the coordination of mono-articular muscles and bi-articular muscles, and it was showed experimentally that a method by joint torque was not suitable. In this study, the relationship between output force distribution and joint torque was made clear more.

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This paper describes an optical visualization method for a transparent object that is capable of realizing high speed tracking of a motile cell without the need to use fluorescent labeling. This method visualizes a non-labeled cell as a periodic light intensity distribution by deriving the diffracted light of a single frequency from the sample. Using this periodic pattern, a high response photodiode can be employed to measure the velocity of a transparent cell. We propose an optical spatial-filtering method to select the spatial frequency component, which introduces two pinholes in the optical Fourier-transform plane. The positions of these pinholes are the two focusing points of the ±1^st-order diffracted light for the selected spatial frequency. By blocking the 0^th-order diffracted light, which includes the regular reflection component from the surface of the cover glass that is the main source of stray light, a laser of high coherence and high power can be used as the light source. We could clearly observe three kinds of transparent cell (lymph cell: JURKAT, white blood cell: K562, breast cancer cell: YMB-1-E) as periodic light intensity distributions. In addition, we confirmed that this pattern moves in accordance with the translational movement of the cell.

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Backlash of reduction gear produces troubles in case of positioning of robots and NC machine tools. It sometimes causes deterioration of positioning accuracy and self-excited vibration. To overcome such troubles special reducers, for example the harmonic drive or RV drive. But such reducers have special structure, so the cost of the reducer becomes expensive in robot or NC system. In this study, a new control method, named twin motor system is studied, that is two servo motors are controlled cooperatively and compensate the backlash of reduction gear.
In this report, a basic simulation model of backlash model is proposed and conditions of twin motor pinion and output gear is analyzed. Experimental results of servo stiffness improvement and 1 pulse positioning accuracy are reported.

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