This paper deals with geometric aspect of machined shapes and a machining process, which correspond directly to the machining process model. In order to make robust assignment rules of machining process, the working tool and operating step were introduced in the previous report. Moreover, to capture the essential information, the dimensions of operating step and working tool are also proposed as the parametric representation of them. However, it is necessary to consider the geometric representation of operating step and working tool, because the geometric information is used in feature extraction process from product model, and essential information of process plan are a tool shape and a tool path. In this paper, geometric model of working tool and operating step in three axis milling machine is discussed based on form shaping function. 16 classes of working tool are also proposed for the process planning.
Recently, many new potential uses of telerobotics and virtual reality have been explored in medical field. In order that a human operator can easily and intuitively execute the given micro operation, the development of suitable visual and haptic interfaces and the accurate registration of them are significantly important. However, these technical subjects are not easy to solve and have not been seriously considered. HMD is unsuitable for the surgical application because of its weight, restriction and narrow range of view. Recently, an immersive projection technology is drawing the attention for the virtual reality. In this paper, a compact and accessible spherical display with a stereo viewing system is discussed as an interface of teleoperation. The operator looks into the spherical display like a fortuneteller viewing a crystal ball. This environment is different from the immersive one surrounded by screens. The validity of developed system is confirmed by the experiment.
This paper describes comparative study of the light-section method and confocal microscopy in the visual inspection of a LCD. Confocal microscopy with coaxial lighting gives a bright-field image and is often affected by an interference pattern appearing in a gap surrounding a foreign particle between the layers of the LCD. Also, scratches or dust on the surface of the LCD obstruct observation of the foreign particle by occluding the particle image. The light-section method gives a dark-field image and dose not produce any obstructive interference pattern. This method was robust for the scratches and dusts on the surface and was successful in detecting the foreign particles included in the LCD panels in wide field-of-view configuration using plane illumination.
This paper considers salt water fishing tackles consisting of line, hook, bar float, primary sinker and secondary sinkers. The line with the sinkers and the hook are modeled by a multilink system connected with the float. A new algorithm is proposed to calculate acceleration terms satisfying Newtonian kinematical equations. The computational requirement varies only linearly with the number of links because the algorithm is based on a sweep-out operation on a threefold diagonal matrix with a simple structure. A comparison is made with a well-known Featherstone algorithm that is based on articulated body inertias. Animation results with 22 links subjected to tidal flow and wave produce typical tackle behaviors consistent with expert experience. The animation is useful for design of tackles and discrimination drills of fish hits.
These are many kinds of geometrical gauges used for calibration of machine tools and coordinate measuring machines (CMMs). A step-gauge is a kind of calibration gauge, It consists of many short block-gauges. Block-gauges were directly calibrated by an interferometer using method of exact fraction. The method, however does not apply to the calibration of step-gauges because of their complicated structure. The calibration works are very important missions in national metrology institutes (NMIs). We developed the step-gauge calibration system that consisted of a CMM and an interferometer. In this paper, we describe the performance of a CMM system combined with an for step-gauge calibration and the evaluation of the measurement uncertainty. The uncertainty in measurement using this system is about 1.0μm(k=2) for 1-meter measurement.
Atomic force microscope (AFM) nanofabrication properties based on mechano-chemical processing due to diamond tip sliding on silicon in ambient atmosphere are studied. The processed height and depth dependencies on load and diamond tip radius were evaluated. Diamond tip of about 200nm radius sliding produces protuberances on the silicon surface. In contrast, about 50nm radius tip sliding produces grooves on the silicon surface. Using about 100nm radius tip, both protuberance and groove are produced. To clarity the mechanism of silicon protuberance and groove processing by diamond tip sliding in an atmosphere, the contact stress analysis were perfomed by boundary element method. Oxidation of silicon is speculated to be caused at the rear edge of sliding contact area that the elongation stress is the highest. This reaction forms silicon oxide in both protuberance and groove processing. To clarify the possibility of these processed parts on silicon surface for the application to wet etching mask, etching properties with KOH solution were evaluated at room temperature. The sliding of diamond tips produces the silicon oxide layer that works as KOH etching protective mask. AFM mechanochemical processing layers are expected to act as etching mask for selective wet etching.
Diode laser beam of 10W is applied to laser forming of stainless steel of 0.1 mm in thickness. The effect of pre-bending is discussed on the basis of the experimental results. The pre-bent plate is always bent towards the pre-bending direction whether or not the beam is irradiated on the opposite surface of the plate. Furthermore, the range where the pre-bending effect works is also discussed. From the experimental characteristics, objects of complicated shapes are made and demonstrated; furthermore, the making procedure is described.
This paper deals with machinability of BN added steels in face milling. In this study, work materials including different content levels of Al, B and N were cut with a carbide tool P10, a TiN cennet tool, a TiC cermet tool and a TiCN coated carbide tool. When face milling the steels with the carbide tool P10 and the cermet tools at the cutting speed over 200 m/min, steels containing Al, B and N caused much smaller flank wear but larger crater wear than S45C. While in face milling of BN added steels by the TiCN coated tool at the cutting speed of 300 m/min, the crater wear rate was drastically reduced than that of S45C. In the cace of face milling in low oxygen atmosphere, crater wear of the carbide tool were also reduced. It was concluded that the machinability of BN added steels in face milling was influenced by tool materials, Al, B and N content of work materials and cutting atmosphere.
The authors have proposed a generalized centerless grinding defined for four modes of combinations of set-up conditions of positive or negative center-height angle and positive or negative work-piece revolution in spinning directions. The rounding mechanism of the generalized centerless grinding has been analyzed in general and derived the generalized rounding effect criterion diagram. But in the previous papers, focusing a dynamic stability of rounding effect, the top angle of work support blade was not taken into analysis considering less effect in comparison with the center-height angle and the work speed in revolution. Therefore, geometrical/statical stability in rounding effect was out of analysis. In this paper, an effect of the top angle of work support blade is taken into analysis as well as the effect of the center-height angle and work speed in revolution. And both geometrical/statical stability and dynamic stability can be analyzed quantitatively by solving characteristic root using vector locus coincidence method. In viewpoint of geometrical/statical stability, it is also clarified from this analysis that the rounding effect of positive center-height angle modes is more stable than that of negative center-height angle modes.
The study deals with developing a new method to fabricate various shapes inside a hole. A hole shape is limited to straight one in the practical machining manner. However, it often happens that the best hole meeting the requirement is not straight but more complex shaped one. In the study, hence, a new device is developed, which can make complicated shapes inside a hole. The device consists of an electrode for electrical discharge machining and some mechanical parts, and is installed on an electrical discharge machine (EDM). The device and EDM move as a reciprocating block slider crank mechanism. Namely, a translational motion of the EDM head can be converted into a rotational motion of the tool electrode. This results in machining the shape similar to the electrode locus. Consequently, if the machining mechanism is applied inside a hole, a semicircular shape can be created inside the hole. Moreover, the use of the electrode with slits makes it possible to fabricate fins inside the hole. From experimental results, it is found that the device has the potential of fabricating the semicircular space and the fins inside a hole.
This paper describes the equivalent friction coefficient on the connecting portion between chuck-part made of aluminum-alloy and spindle made of steel, which is obtained in the experiment. The tangential force is loaded by a PZT-element in the direction perpendicular to the bolt thrust. The tangential force and the bolt thrust are measured with load-sensor of Kistler and A/D converter, and the equivalent friction coefficient is calculated as the ratio of those forces. It is clarified that the equivalent friction coefficient of 0.15-0.25 is reasonable near the start of sliding displacement as the boundary condition of FEM analysis and that the coefficient gradually increases with the increase in sliding displacement between chuck-part and spindle under small displacement.