A new non-contact fluid bearing, which utilizes traveling waves, is proposed in the present research. The moving part is supported with a thin fluid film compressed by the waves traveling radially on the bearing surface. Conventional hydrostatic bearings utilize externally compressed fluid, which requires plumbing and large facilities. The proposed bearing realizes non-contact precision motion without those facilities, and furthermore it has a capability to electrically control the bearing force or clearance. A prototype air bearing was developed on the basis of the proposed principle by utilizing piezo-electric actuators. Its non-contact smooth motion was confirmed, and its basic performance is clarified experimentally in terms of stiffness, bearing clearance, load capacity, pressure distribution of the air film, etc.
Although the significance of the thermal contact characteristics of joints in machine tools has been pointed out for a long time, the thermal contact resistance, that is one of major factors of the joints, has still many uncertain facts. Therefore the resistance was not considered or the empirical value of the resistance was used in the past analysis of the machine tool thermal deformation. Then it is difficult to say that the thermal characteristics of the machine tools can be analyzed exactly. Moreover few researches compared the analytical results with the experimental ones. Accordingly, in this research the method to incorporate the measured value of the thermal contact resistance into the FEM analysis is proposed to express the nonlinear temperature distribution near the joint and the validity of the proposal is considered with the experiment. The conclusions in this research are as follows. (1) The contact thermal conductivity element can be introduced to incorporate the measured thermal contact resistance. (2) λe and dc, those are main factors of the contact conductivity element, are determined uniquely by the thermal contact resistance R, and the nonlinear temperature distribution near the joint can be analyzed by FEM using the element.
This paper describes the mechanism of cutting temperature rise in micro drilling on Printed Wiring Boards (PWBs), which affects the micro-drilled hole wall quality. The drill temperature monitored by a thermography was evaluated in drilling. Moreover, we investigated the influence of drill workload, which was calculated with cutting force measured by a dynamometer, on the drill temperature. The following conclusions were reached: (1) The drill temperature tends to increase with the drill workload caused by frictional torque between hole wall and the land or margin of drill. (2) The frictional torque increases with the spring back of drilled hole wall in drilling. The spring back of drilled hole wall increases with the outer corner wear of drill cutting edge in drilling. (3) The reduction of the workload by the friction seems to be effective in order to obtain the high quality micro-drilled hole wall.
This paper describes the elucidation about influence of dilute NaCl electrolytically water on the surface of oxygen-free copper material. First, by the immersing experiment, it clarified an etching performance to the oxygen-free copper surface of electrolytically oxidized water, electrolytically reduced water and HCl solution. At the same time, the relation between the specific value of electrolytically oxidized water and etching speed of the oxygen-free copper was clarified too. Next, it made the influence which electrolytically water and HCl solution give the shape of the oxygen-free copper surface using SEM and laser 3D image clear. Lastly, by Auger electron spectroscopy, electrolytically water made an influence over the chemical composition of the oxygen-free copper surface layer and so on clear. By above mentioned experiment reviewing, it got the conclusion that dilute NaCl electrolyzed water can be used for surface treatment of the removal of the oxide film and so on in the surface of the oxygen-free copper.
Using single crystal diamond tool, in the previous research, the ultra-precision cutting of titanium metals is examined roughly at the depth of cut over 5 μm. The huge wear of diamond tool is observed at the short cutting length and the surface roughness becomes over 200 nm (Rz). In the report, the ultra-precision cutting of β titanium alloy (Ti-22V-4Al) at low depth of cut of 1 μm with diamond tool is tried. From the results, the high crystal grain boundary step observed at large depth of cut is not found on the finished surface. The surface roughness below 100 nm (Rz) and below 200 nm (Rz) is formed at the initial cutting process and kept until the cutting length of 20,000 m, respectively, though the light wear of diamond tool occurs.
In late years, multi-wire saw has been used for the slicing of a silicon ingot for solar batteries, and multi-wire sawing is going to become the mainstream of precision slicing method for hard and brittle materials. However, in slicing by multi-wire saw, the technique for appropriately evaluating the severity of the slicing state or the slicing conditions has not been established yet. Therefore, there are a lot of parts where it relies on expert's experience rule as for the decision of the slicing conditions. In this study, an evaluation functions to evaluate severity of a slicing state or slicing conditions are derived. An analytical technique for modeling the machining process used by other abrasive machining to derive the evaluation functions is applied for multi-wire sawing. And evaluation function “mean depth of cut”, “normalized depth of cut” and “specific slicing energy” are derived. In this paper, slicing experiments are done under various slicing conditions, and it is examined about utility of the derived evaluation functions. As a result of investigation, utility of the derived evaluation functions were confirmed.
Manufacturing technology for stainless steel double skin panels using laser spot welding was developed and some static strength properties were carried out. And this panel has been examined for the feasibility of practical utilization. The results obtained are summarized as follows; (1) Manufacturing technology was established on which there are invisible welding marks and the corrosion resistance and appearance are equivalent to original metal surface. (2) Calculate method of the moment of inertia of area of this panel is established. (3) This panel is approximately 75% lighter than the bulk material in equivalent flexural rigidity. (4) Any laser spot welded site is not broken in region of below maximum load as well as localized buckling in mechanical tests. (5) In application of this panel to vessels and vehicles, simulation model of stiffness and strength of this structures life prediction of this panel based on fatigue strength analysis for panel reliability prediction technology is required.
In order to implement cell surgery on a chip-based system, we have been developing microneedle arrays capable of introducing desired biomolecules (nucleic acids, proteins, antibodies, etc.) into living cells and the parallel extracting biomolecules expressed in the cells. This paper presents a novel and simple bath fabrication process for out-of-plane, hollow silicon dioxide (SiO2) microneedles in array. The micromachining technique involves standard photolithography and a combination of an anisotropic deep reactive ion etching (DRIE) process for producing thorough holes into a Si substrate as a needle mold followed by wet oxidation and an isotropic XeF2 etching process for leaving SiO2 microneedle structures. This allows a good degree of flexibility with respect to different needle designs such as needle sizes, shapes, and spacing between each needle with a one-mask process. An array of microneedles with a circler tip shape (an inner diameter of 3.5 μm, an outer diameter of 6.0 μm, and a height of 90 μm) were successfully fabricated.
Feature parameters of surface texture parameters based on critical points and local geometric features can be utilized to evaluate the subtle relationship between surface function and surface topography data of functional engineering surfaces. This paper describes the parameterizing process of significant surface features derived from the topological theorems for triangulated surface topography data. A reasonable method of determining the threshold value for the significant surface features is presented with prerequisite calculation conditions.
This paper reports on the rotational control method of the proximal two-beam optical tweezers. The proximal two-beam optical tweezers can rotate a microsphere in the optical axis direction by using the light pressure as the rotational torque. To apply the proximal two-beam optical tweezers to the arbitrary-shaped microspheres, the rotational torque should be operated in two dimensions. For this purpose, we propose the optical pulse width modulation. This proposed method controls the amount of light received per unit time by operating the span of the illumination time. To change the illumination span, the pencil of rays is scanned by the galvanometric mirror independently in two dimensions. We verified that the rotational torque of a microsphere 10μm in diameter can be controlled.
This paper proposes a method to detect an object with slight vibration in a scene image composed by multiple frame images. In the method, the value of the vector that represents strength and a direction of a gradient of gray-levels at every pixel in each frame is used to detect slight vibration of an object. The differential values between neighboring frames are accumulated to improve the sensitivity for detecting the slight vibration. After the accumulation for all frames in the scene image is completed, the status of the slight vibration is evaluated at every pixel. The experimental results show that the slight vibrations that were not detected by the visual sense in the experimental scene images were detected stably by the proposed method in comparison with the conventional frame differential method.
Planar linear motor is a kind of 2D precision positioning stage, which is different from the usual XY stage and is composed of multiple linear motors arranged orthogonally in a same layer. It is a general way to employ a 3-axis laser interferometers and square-mirror as the positioning sensor of Sawyer planar linear motor for applications with nano meter order resolution. A geometrical calibration method is proposed according to the errors affecting the measurement of the laser interferometer, such as the profiles of the two plane mirrors and the flatness of platen. The method is easy to perform on the user side and useful to evaluate the single geometrical motion error without the standard square-gauge or the cross grid-scale. In this paper, the profiles of the x and y axis plane mirrors are measured by the tangent method and the straightness method respectively. For confirming the measurement results, the 2-point method with yawing compensation is applied to both of the mirrors.
This paper describes the running static analysis of an in-pipe mobile robot using a wheel drive mechanism for straight piping. The wheel mechanism, which is driven by planetary gears and worm gears, can both drive the wheels and press them the wheels against the pipe wall using only an actuator and simple mechanisms. The relation among the size of the load, wheel revolution angle, and the pressing load against the pipe wall is theoretically analyzed and is experimentally examined. The traction force of the robot is calculable with motor driving torque, and the maximum traction force is estimated with no-load driving torque of robot and torque constant of the motor. From the running experiments by the prototype robot, which is 45mm in diameter and 130mm in length, the maximum traction force was at least 20 times the weight of the robot.
This paper describes the new width control system that utilized the diaphragm phenomenon seen in the heat treatment process of a steel plate manufacturing process. This system derives the creep composition formula under the high temperature condition of a steel plate, designs each control system which constitutes a system and verified the possibility of this new width control system by computer simulation (1/10 scale). As a result of examining the capability of the equipment and investigating the change action of width by a numerical simulation, following result is obtained that width control is realizable on calculation. By this system, the improvement in manufacture efficiency and large cost reduction are expected since width change can carry out easily and sharply.
In order to shorten design lead time, recent manufacturers usually employ diversion design by using a knowledge base CAD system. In diversion design, a CAD data should be constructed by an appropriate modeling procedure in order to respond to a future diversion. However, especially a novice CAD operator hardly thinks about a modeling procedure for diversion. Therefore, it takes much time for an operator to understand a modeling procedure of CAD data which is constructed by the other, and then design lead time cannot be shortened as much as expected. We have been developing a modeling procedure document creation system, called C3 (Cubic), which supports a CAD operator to understand the modeling procedure in a short time. By applying this system, we implemented "ONT (On the Network CAD Training) system" by which an operator can efficiently learn the modeling procedure online. The ONT system was experimentally operated for verification. As a result, the efficiency of diversion design has improved by approximately 3 times that of former technique.