A method to break glass plate was proposed for substrates of display panel by CO2 laser beam heating. Generally, glass plate is broken by growing micro-crack which is generated during scribing from tip of a chisel under optimum load. And then, the generated micro-cracks are grown by mechanical force applied to the scribed trace. For laser breaking, the micro-crack is grown by tensile stress due to thermal expansion which arises from temperature rise by a CO2 laser beam irradiation onto the scribed trace instead of applying mechanical force. This paper deals with experimental results of the optimum laser irradiating condition and discussion of the laser breaking mechanisms. It was possible to break the glass plate finely and precisely without applying mechanical force at the same scribing velocity.
Various burrs in size and shape are formed at workpiece edges in metal cutting and cause many problems in many production lines. Therefore, the reduction and control of the burrs are necessary. To reduce and control the burr in size and shape, a conceptual understanding of the burr formation mechanism is necessary, due to the variety of burrs in the size and shape. In this study, to understand the burr formation mechanism, burr formation process in orthogonal cutting for various material were analyzed by a finite element method and micro-machining experiment in a scanning electron microscope. As the results, important factors of workpiece property and cutting conditions in burr formation were shown and a framework for the burr formation process based on the material property was presented. Moreover, the relationship between the formation process and the burr size was considered quantitatively.
In this study, both a short-time cutting and a friction welding tests were carried out to evaluate the properties of adhesion quantitatively between the titanium alloys such as Ti, Ti-6A1-4V, βC-Ti and the cemented carbide tool, K 10. The bonding phenomenon in the friction welding was very similar to the adhesion phenomenon in cutting from the metallurgical point of view. βC-Ti alloy was easy to adhere on the tool comparing with Ti and Ti-6AI-4V alloys. Moreover, the reaction layer in which titanium and carbon were enrich, was observed at the interfaces between the alloys and the tool in the friction weld joint even if the friction time was only 0.4s. The morphologies of reaction layers were different among the alloys. It was concluded that the properties of adhesion depend on the reaction at the interface between titanium alloys and tools, and the morphology of the reaction layers. Furthermore, the adhesion phenomenon in cutting may be reproduced using the friction welding.
This paper deals with influence of chemical compositions of work materials and cutting tools on machinability of BN added steels. In this study, work materials including different levels of Al, B and N were turned with carbide and cermet tools which also included different levels of Ti at high speeds. Furthermore, the free-machining mechanisms were discussed on the results obtained from cutting tests. Machining tests showed that BN added steel including Al had very good machinability when they were machined with P-grade carbide tools. The machinability, however, decreased when the work material had low content of Al, B or N. Up to 0.06% of Al in work material, it showed that the larger amount of Al the bigger effect of machinability. The machinability of BN added steel was influenced by Ti content of cutting tool, that is, the higher content of Ti the smaller tool wear. When machining BN added steels at high cutting speed with Pgrade carbide tools, Al and N were detected as a layer, and the layer was considered as A1N by Xray diffraction analysis. AlN layer on the carbide tool surface prevented the inter-diffusion between cutting tool and work material. The effect of A1N on the diffusion was considered as the mechanisms of free-machining of BN added steels.
In the present study, the doctor blade method is employed to fabricate thin film electrolytes applied to the solid oxide fuel cell (SOFC). Yttria Stabilized Zirconia (YSZ) is adopted for the electrolyte thin films. The electric property of the YSZ thin films fabricated under various sintering conditions are compared in terms of the ion conductivities. The relation between the grain size, sintering time, sintering temperature and the ion conductivity are discussed in detail to evaluate the electric property of electrolyte. Then, a single solid oxide fuel cell is made experimentally, and the current-voltage relation and the power density of SOFC is investigated. Finally, it is shown that the present SOFC of YSZ electrolyte proved to be good performance of power density 163mW/cm2.
This paper proposes the method dealing with the concept of factory floor culture (FFC) tentatively in order to discuss it among many machining engineers and researchers deeply. Firstly, FFC is explained and treated as manufacturing culture for machining process aspect in this paper. Then FFC is defined with steadied folklore-phenomenon, and the phenomenon is simulated using a contact process in case of tool-usage in the Stone Age. Furthermore, motivation of NC machine purchase is analyzed associating with a questionnaire investigation of it in Japanese small scale companies. Finally, the analyzed result is illustrated by the Catastrophe Theory.
This paper proposes a model of design information which can handle situation around designer and verify its validity by means of design experiment. The authors think design process based on a framework of problem solving does not describe explicitly all of design activities. In order to compensate for 'this insufficiency. the authors propose a concept. of focusing process which is clarified by designer's explanation of their problem solving processes. Focusing process is also supposed to be design activities which take a role of extracting information from designer's situation, as well as problem solving process. Based on this concept. design experiments which consist of two sessions are carried out in order to study its structure and characteristics. The authors take advantage of the protocol analysis with the explanation of design activities by means of Q A showing designer the records of design process on video. Results acquired from two different types of designers are reported. Several common and different patterns of process are found out which support the validity of the concept here.
Comparing object shapes is essential for many computer vision tasks such as object model categorization and object recognition. This paper presents a method for comparing an object reconstructed by faces viewing from a specified point with a geometric model. The basic idea of the method is as follows: (1) The convex hull of the viewed faces is constructed in order to supplement the part which is not viewed from the specified point. (2) The viewed faces are compared with faces of the geometric model, and the convex hull of the faces corresponding to the viewed faces is made. (3) The numerical similarity among these two convex objects is calculated according to the algorithm for determining similarities of convex polyhedra described in the previous report. Various cases of object shapes have been tested. The experimental results show that this method is good for recognizing shape similarity based on viewing faces.
As well known, rotating machinery is playing the important role in various industrial fields. Therefore, practical and reliable condition diagnosis techniques for the rotating machinery are essentially important for safe operation of machinery. Since the vibration of rotating machinery in failure condition is controlled by nonlinear dynamics, this paper presents a new diagnosis method in which chaotic dynamics is applied to detect the failure such as cracked shafts of rotating machinery. To verify the diagnosis ability of the proposed method, the numerical simulation for the vibration behaviors of the cracked shaft by using chaotic analysis is successfully performed and proves to be useful.
A robust approach to the half-tone template-matching problem is proposed. It is based on a novel statistic called 'Increment Sign Correlation (ISC)' which is also proposed in this paper. ISC is formulated mathematically as a statistic which is a kind of cross correlation between binary coded increment signs and has a probabilistic binary or normal distribution. Characteristics of the distribution depend on both average contrast of the template picture and variance of additive noise. The approach utilizes ISC effectively for matching partial pictures with the template. It is applied to recognition of glossy objects with highlights and detection of sudden change in natural scene. Robustness of matching methods is much necessary in these tasks for avoiding brightness errors almost only by illumination. Experiments with real pictures show an effectiveness of the proposed approach.
DC servo motors that are made as manufactured goods in the factory are widely used as actuators for driving many automatic machines. Then the manufactured driver (amplifier) that is matched to its servo motor is coveniently chosen to drive when aiming at high performance of the motion control. Motion of motor that is driven by the manufactured servo driver has very complicated dynamic characteristics. In this study, it is tried to make clear about inner composition of the servo driver through measuring the dynamic characteristics of the servo motor which is driven by the manufactured servo driver. And it is tried to express mathemati-cally transfer function of the velocity control system.
This paper presents a newly developed displacement sensor system. Usually, interferometer or linear encoder is used to monitor motion of precision stages. However, these sensors are operated in one dimension only. Hence, if device has many degrees of freedom, number of sensors to monitor its motion has to be the same as the number of degrees of freedom. It adds complexity to the designing machine layout. In this study, 2-dimensional displacement sensor system is proposed. This system consists of 2-dimensional angle sensor and 2-dimensional angle grid. Because of the angle independency of x and y direction, it is possible to monitor x- and y-components of motion from the angle sensor outputs. This system also can improve its ability by using in-situ self calibration to calibrate sensors and angle grid. 2-dimensional angle sensors have been developed for proposed system and the basic performance has been tested. The sensors can clearly detect 2-dimensional angle grid. From displacement measuring experiment, it appears that proposed system could monitor stage movement within 2 μm errors with in-situ self calibration compensation.
This study proposes a six-degree-of-freedom fine motion mechanism with isotropic stiffness and positioning resolution in XYZ directions. In the previous report, the optimum link layouts with the above characteristics have been designed by the singular value decomposition. In this paper, construction and experimental results have been described for the designed parallel mechanism. The stiffness values in translational directions and in aβ directions became equal. The stiffness value in γ direction, moreover, was two times those in γβ directions. The maximum movements of the stage were 10μm in XYZ directions. 200μrad in aβ directions and 100μrad in γ direction. The positioning errors and the motion errors were less than ±0.08βm and ±l.0μrad. The dynamic characteristics in six directions were equal under 1-50Hz frequency range.
This paper describes the self-alignment principle and characteristics using liquid surface tension for the assembly of microparts. In the principle, the attractive force caused by liquid surface tension is used and servomechnanisms which are too large to align microparts are not required. The surface of each micropart is divided into two kinds of areas: the wettability of one area is higher than that of the other. Using the microparts, the self-alignment is realized as follows: (1) first, a drop of liquid is put on high wettablity surface area of the first part, (2) next, the second part is put on the first one, (3) and then the second part is moved by the surface tension of the liquid so that the wettability area pattern of the first part overlaps with that of the second one, (4) finally, the alignment is accomplished. In this paper, water is used as the liquid. The effects of the water volume change, the position and angle changes of the second part before the alignment on the alignment accuracy are examined experimentally. The experimental results prove that the average of the final alignment errors becomes less than 10μm even if an initial alignment error is 100μm.
This paper presents a new type of electrostatic actuator (Conical Spring Linear Actuator : CSLA) capable of vertical stepwise motion to a substrate. The CSLA is made of a thin film metallic glass (TFMG) of a conical spring shape. The TFMG is expected to be a material suitable for micro structures because it is an amorphous alloy which free from anisotropy and defects originating from the crystal structure. Micro machining of TFMG is possible by a lift-off technique. Moreover TFMG softens at a certain temperature range called the supercooled liquid state, which allows surface micro-machined TFMG structures to be easily formed into three-dimensional shapes. This micro forming technique allows the conical spring shape of the CSLA. The conical spring acting as a moving electrode was assembled on a fixed four-section electrode on the substrate so that the actuator could make a stepwise motion. The CSLA showed vertical stepwise motion of four stages to the substrate by switching the electrodes, which were applied in rotation at a constant voltage (17V). The total displacement of the CSLA was limited to 30μm due to the unexpected deformation of the conical spring.
In this study, construction of an automatic inspection system of X-ray film is tried. Films used in this study are acquired by X-ray inspection of welded joints. Because the X-ray radiographic testing method is useful in inspecting the inside of weld metal, it is often used in industries. However, skilled inspectors for X-ray radiographic testing are gradually decreasing, recently several methods to detect weld defects from films automatically have been investigated. But, a X-ray film involves a number of noise, and defect images show very low contrast and various shape in spite of the same kinds of defect. Moreover, when unevenness on the surface of bead is large, detection of an internal defect image is difficult with the previous technique which depends on only a two-dimensional film image. Therefore, in this study, the new image processing system was constructed. Shadows by the surface unevenness in the X-ray film is removed using the range image of the bead surface on this system. That is to say, first of all, the range image is matched to X-ray image about resolution, intensity and location. Then, the transferred image is defined as the background image and subtracted from the X-ray image. In this process, matching method between range image and X-ray image is important. In this study, the matching method using contrast indicator was constructed.
This paper presents a development of a reseat module which is included in a fast and accurate touch trigger probe for coordinate measuring machines (CMM). In general, the reseat module absorbs contact force for safety and repositions the probe stylus. A "six-point-contact-reseat-mechanism" is conventionally used as the reseat mechanism. The elastic deformation of the six contact points varies according to the stylus touchback motion, and a dispersion of the elastic deformation brings the dispersion of the reseat position. The dispersion of the conventional reseat position is shown theoretically and experimentally. Both dispersions reach 1μm order in the conventional one. A new reseat mechanism installed radially three piezo-elements improves the dispersion by resetting the elastic deformation. This structure is called High Reseatabilty Mechanism (HRM). The dispersion is improved a 0.2 μm order after the HRM operation.
A touch trigger probe sensor for coordinate measuring machines (CMM) detects a contact between a spherical stylus tip and an object to be measured. The conventional probes are not suitable for high speed measurement and high accuracy measurement of sub-micrometer order. A piezo-element novel sensor construction and a detecting circuit are proposed. To detect the impulsive contact force, four piezo-elements are mounted on a base of the stylus. The impulsive force brings a longitudinal wave and a bending wave which transmit separately in the stylus. The time difference between two waves arriving to the piezo-elements enlarges the detected position error. The two waves are detected electrically by the piezo-elements and separated by the detecting circuit, and the former signal is delayed so that two waves are seemed to arrive simultaneously at the piezo-elements. By the above signal processing, the error are improved to at most 50nm dispersion, at all of the force directions in a half sphere of the spherical stylus tip for a probing speed of 3-60mm/s.