Today, environmental concerns caused by industrial products have grown up to a critical amount that can not be ignored. It requires us to worry about the environmental issues, particularly, from the viewpoint of trade-off relationships at the design stage. This paper presents the concept and the implementation of the Green Browser, which is intended to enable the designer to clarify trade-off relationships among goals of the product over its life-cycle. The concept of the Green Browser is a model sharing for life-cycle design and the representational scheme of the model. The model sharing mechanism between designers and users on the Web are implemented. A case study on building the strategy model of a refrigerator is presented to illustrate the strategy model.
This paper proposes a method on fundamental process design with timing constraints. In the fundamental design phase, a designer is required to make a timing-chart from qualitative information concerned with timing constraints such as requirements and causality of processes. The purpose of this method is to present a way of deriving a solution regarding process timing from qualitative information. According to the method, a designer is able to formulate requirements and constraint conditions of process timing by the use of interval-based temporal logic. Then the method gives an algorithm to search timing solution. The algorithm, simultaneously, indicates additional constraint conditions concerned with length of interval in case of need. To verify the method, a support tool of software program is developed and the effectiveness is confirmed by the results of process timing design of event-driven type software of an asynchronous data transmission equipment.
Kaleidoscope is a device to convert power density distribution of laser beam. Cylindrical pipe kaleidoscope and taper pipe kaleidoscope are applied to laser drilling process in the present research. The shapes and dimensions of the kaleidoscopes are designed based on the theoretical analysis of the power density distribution of the laser beam converted by the kaleidoscopes. Laser drilling experiments of acrylic resin plates are carried out by applying both the kaleidoscopes and the conventional lens. The experimental results are discussed from the viewpoints of the depth and the cylindricity of the acrylic burn patterns. The following remarks are concluded based on the experiments. The shapes and dimensions of the burn patterns are not affected so much by the distances between the kaleidoscopes and the work plates in the case of drilling process by use of the kaleidoscopes. The taper pipe kaleidoscope is most suitable for the drilling process from the viewpoint of the cylindricity of the burn patterns.
This research deals with a monitoring method for lapping process. In the preceding paper, it had been shown that the surface roughness of the work can be monitored in process by detecting the acoustic signals transmitted in the lapping jig. To detect the signals efficiently with a piezoelectric ceramic sensor equipped on the jig and to evaluate the lapping condition properly, it is necessary for the jig to have simple characteristics of vibration. In this paper, a conical-horn type of lapping jig was newly designed to have simple structure, wide frequency range, high acoustic gain and high reproducibility. The experimental investigation in the frequency range less than 10kHz showed the acoustic power level of approximately 2kHz could be used for the process monitoring. It was also confirmed that there was a linear relation between the acoustic power level and the surface roughness of the work.
Nonlinear optical crystals can convert the wavelength of laser diode from infrared to green or blue. To achieve higher conversion efficiency, wave conversion devices using nonlinear crystals have to satisfy the phase matching condition. Generally the phase matching angle acceptance of nonlinear crystals is so narrow that it is very difficult to achieve the theoretical conversion efficiency. This paper investigates the theoretical angle acceptance of few kinds of organic nonlinear optical crystals. The narrowest angle acceptance was 0.0055°(λ=1064nm, L=10mm, power ratio 99%) of Chalcone TC-28. To satisfy the phase matching angle acceptance, a new optical surface generator which can determine the optimum crystal orientation to get the highest wave conversion efficiency was also proposed.
In this paper, a new grinding technique, the ultra-low infeed grinding, in which infeed rate of wheel head is controlled at the beginning of spark-out state, is proposed in order to improve significantly the surface roughness of workpiece. Main conclusions obtained are as follows (1) The ultra-low infeed grinding can be superior to the thermal deformation rate control grinding. (2) In the ultra-low infeed grinding under this experimental conditions, the surface roughness of workpiece can be improved by 35 % at the point of 5 s spark-out state and the spark-out grinding time can be reduced by 72% comparing with the conventional grinding. (3) It is experimentally made clear that the optimum of ultra-low infeed rate and of infeed time exist from a viewpoint of the surface roughness improvement process.
In the manufacturing process of integrated circuit, graphite plate with many fine holes has been used as an electrode in plasma etching process. Recently, it is examined to use a single crystalline silicon as the electrode in order to minimize the contamination. However, it is difficult to machine accurately by the conventional methods, since the material removal is due to brittle fracture. The machining force in EDM is very small compared with that in conventional machining, therefore the possibility of high efficiency and high accuracy boring hole in a silicon ingot by EDM is experimentally investigated in this study. The removal rate of silicon is from 4 to 8 times higher than that of steel, while the electrode wear is from one-fifteenth to one-seventh times smaller. When the electrode advances at the exit of hole, stagnation region appears in which the electrode retracts suddenly and the machining becomes unstable. In order to prevent this phenomenon, the copper plate is closely attached under silicon ingot firmly. In this method, better hole can be obtained without chipping. Besides, there is no sticking of insulator which contains silicon oxide and copper oxide on the wall of hole in this case. Furthermore, it is proved that even high aspect ratio over 200 boring is possible.
As a method for profiling an electroplated diamond grinding quill in the noncontact manner, the laser beam-aided truing (LBT) is experimentally investigated. In the LBT, a pulsed YAG laser in the Q-switched mode is irradiated in the tangential direction of the quill working surface by means of CNC movements in order to allow the diamond grains to be aligned on a desired profile. The experiments were conducted by fastening a jig grinder of air-turbine type onto a NC table of YAG laser irradiation equipment. From SEM observation of diamond grains on the quill, it is clarified that the thermal impaired tips of diamond grains are removed by graphitization followed by oxidation. The changes of cutting point density and grain protrusion have been traced with the laser proximity as a parameter, and the laser beam position. at which the truing effect appears is found at the position where the laser beam interferes with the quill by about 70μm deep from the quill outermost surface. The electroplated diamond quill applied LBT under an appropriate condition brings about a little higher grinding force, however, the finished surface roughness is better than that of the quill without laser treatment.
In order to evaluate the mechanical properties of diamond-like carbon(DLC) thin films formed on the substrate of single crystal copper or aluminum by EBD, the indentation test using Vickers diamond is carried out both in an ultramicro hardness tester and in a computer. Experimental results obtained are compared with those obtained by MD simulation. The natural vibration of carbon atoms in DLC model made by MD simulation using Tersoff potential energy coincides well with the Raman spectra of the DLC film which is measured to characterize the structure. MD simulation makes it possible to observe the mechanical phenomena occurred in the DLC film in the order of atomic scale during the indentation process, and to determine the raw hardness of DLC thin film by means of subtracting the influence of the substrate from the experimental result.
This paper describes the prediction of the fracture area and fracture probability in failure of a cemented carbide end-mill under side cutting and side-end cutting operation by the method introduced in previous paper.The prediction method by FEM computer simulation is applied to several cutting conditons using the two flute end-mills with helix angle 30° and 0° in larger cyclic number of cutting load. The main results obtained are as follows: (1) Theoretically and experimentally, failure originates at the cutter sweep and the fixed end independently of cutting condition. (2) Only by modifying of applied cutting load, the calculation result approximately agrees with the experimental result in every case. (3) The method can be applied not only to an end-mill with helix angle 30° but to with 0°.
A robotic machining system composed of a robot manipulator (machining robot), cutting tools, laser displacement sensor (LDS), non-contact three dimensional shape measuring machine (3DSMM), and 3-D shape data processing software is described. The spherical SCARA is used as a machining robot, and satisfactory results are obtained. In particular, the 3-D objects' surface data are measured by 3-D shape measuring machine, and expressed as cloud of points. The 3-D objects' surface machining method using the data is mentioned. Further, the design philosophy and the construction of the developed system are described, and the results of some experiments on 3-D machining are discussed.
This paper proposes a new method of measuring and evaluation for optical distortions of glasses or transparent objects. An optical distortion is evaluated by measured contrast of checkered pattern image viewed through the object. Naturally it makes contrast down caused by focal shift. In this paper, some artificial samples of transparent plastics are used. They have various shape characters of surfaces that will be causes of distorted images. The contrast values of checkered pattern images viewed through these samples are measured with various installation angles by image processing technique. Strong correlation between the contrast and the shape character of surface is shown.
Evaluation of truncated surface asperities is critically important in many industrial applications. It is necessary to compare original profile with truncated one in a discussion of truncation process, i.e., wear mechanism and plateau horning, etc. For the comparison of profiles, we have to relocate truncated profile to original one. But there is a limitation of relocation using a hardware. To relocate accurately, the authors suggest a relocation technique using software. In this paper, the authors present a new relocation technique by corresponding untruncated areas between truncated profile and original one by software. The authors calculate a collation index of two profiles by optimization method. Furthermore, the authors discuss the availability of this technique in simulation data and measured one.