Emerging Technology in Precision Engineering XIV

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Authors: Yohei Oda, Makoto Fujishima, Yoshikazu Kawamura, Morihiro Hideta
Abstract: Machine tools, which are used in factories for long hours and many years, have a great influence on power consumption of the factories. Therefore, reducing machine tool power consumption is one of the important subjects for today’s machine tool manufacturers. In this paper, we will report on our ongoing efforts to improve energy efficiency of machine tools.
Authors: Masayuki Arita, Hiroshi Kawaharada, Hiroyuki Hiraoka
Abstract: To promote the reuse of parts for sustainable society, estimation of deterioration of reused parts is required. For that purpose, we propose a simulation for estimating deterioration of parts that takes into consideration deviation of load caused by deviation of part shape. Preliminary results of the simulation are shown.
Authors: Kishida Keisuke, Toshihiko Nakamura, Hideki Aoyama, Naohisa Mastushita, Akihiko Ushimaru
Abstract: Laser forming, is a plastic forming method using local heat stress which can form sheet materials without dies. Because no dies are required, it enables rapid prototyping and reduced production costs. Many studies have been conducted on laser forming, but almost none on the forming of curved surfaces. The aim of this study is to develop a CAM system for forming curved surfaces by laser. The scanning paths of the laser for forming curved surfaces are based on a method applied in shipbuilding industry. The method uses the maximum and minimum curvature lines as the scanning paths of a gas burner. Since the two curvature lines intersect perpendicularly, they do not influence each other. The scanning speed of the laser for obtaining the required bending angle was determined based on the basic experiments.
Authors: Martin Hünten, Daniel Hollstegge, Fritz Klocke
Abstract: Manufacturing of micro optical components is approached with many different technologies. In this paper it is presented how the precision glass molding process is enabled to manufacture micro optical components made out of glass. In comparison to the existing glass molding technology the new approach aims for molding entire glass wafers including multiple micro optical components. It is explained which developments in the filed of simulation, mold manufacturing and molding were accomplished in order to enable the precision glass molding on wafer scale.
Authors: Takahiro Ohashi, Ngoquang Thanh, Ryosuke Miyajima
Abstract: The authors have developed a lateral extrusion process with a lost core. The outline of the process is as follows. First, the cavity of a pipe, or a channel material, is filled up with liquid of a low-temperature melting material. The low-temperature melting material is then solidified to become a soluble core of the pipe. The authors call this soluble core the lost core. Next, the material is compressed longitudinally as a composite billet and extruded in the lateral direction. After deformation, the low-temperature melting material is melted and removed. The process can performed in a compression state to control the precise appearance of the product. This study examines a new core material, alumina powder (alumina ball) bonded with wax, as a core material. A mixing methodology for wax and alumina powder is discussed along with the effect of their mixing ratio on the deformation of the pipe.
Authors: Masayuki Nunobiki, Shinji Fukuoka, Koichi Okuda, Hiroo Shizuka
Abstract: This research proposes the application of laser forming to repair dents made in stainless steel sheets. Stainless steel sheets are widely used for the exterior coverings of trains or automobiles. When dents are made in an exterior sheet, it is necessary to detach the panel and strike the sheet from the inside with a hammer. This research indicates that dents were repaired by irradiating them from the outside with a laser beam. It is effective to repair dents without detaching the exterior sheet from the body of the vehicle. In the proposed method, a laser was scanned along the shape of the dent under the condition that the sheet bent by the temperature gradient mechanism or upsetting mechanism. In our experiments, circular dents were made in a 1-mm-thick SUS304 sheet. The laser was scanned along several circular scan lines on the circular dent with a diameter of approximately 20 mm. The depth of approximately 1.5 mm of the dent decreased by 85% using this technique.
Authors: Ekkard Brinksmeier, Oltmann Riemer, Christian Robert, Sven Twardy
Abstract: This paper presents two alternative approaches in mold making for micro forming processes. The quality of formed micro parts is mainly dominated by the process parameters and the surface characteristics of the applied forming tools. Forming dies with advanced micro structures can improve the result of forming processes compared to tools with smooth surfaces. Here an approach of micro ball end milling is described to generate the macro geometry as well as an engineered surface texture on micro forming tools in one machining step. In addition to the surface topography, the die material has a decisive influence on the forming result and durability of the forming tool. Therefore single crystalline diamond represents an promissing material for forming tools, because of its unique material characteristics. On the other hand single crystalline diamond requires unreasonable high efforts for its geometrical shaping. Therefore, this paper will introduce a new approach to machine single crystalline diamond by thermo-chemical material removal.
Authors: Hidetoshi Ogikubo, Naoto Ohtake
Abstract: Bio- Fuel Cell is promising technology to overcome global issue. However, there are many problems in Bio-fuel cell using organism catalyst because research of this type of fuel cell is started in only few years. Purpose of this research is to obtain high electric power using new type of electrode in Microbial Fuel Cell (MFC). Firstly, three types of electrodes were prepared. Those are (1) painted CNT (Carbon Nanotube) by Ag paste, (2) only Ag paste (without CNT) and (3) bare carbon thin plate. MFC with CNT painted (2) electrode generated high current density and high power in MFC, but its E.M.F (Electromotive Force) was decreased. When CNT painting was applied only to anode, high current and power densities were attained without reducing E.M.F.
Authors: Hiroki Kiyota, Fumihiro Itoigawa, Takashi Nakamura
Abstract: A chamfered cutting edge, which is commonly shaped in order to strengthen an edge of a cutting tool consisting of brittle material, easily causes an enhanced adhesion and a burr formation due to high compressive stress anterior to the edge. These problems lead to a detachment of tool material and a notch wear at depth-of-cut line, which would result in unexpected tool fracture. On the other hand, the edge shape promotes formation of a built-up edge (BUE) as a dead metal and can maintain it stably. Actually, the formed BUE is plastically extruded along to the chamfered edge and can prevent formation of the notch wear. In this study, basic experiments to reveal effects of chamfered tool edge preparation, such as chamfer angle, chamfer width and rake angle, on the BUE behavior were conducted. Additionally, the results suggested that the plastic flow in the BUE extrusion can suppress the adhesion if the extrusion is arisen uniformly. Therefore, attempts to control the BUE flow by chamfer surface modification were carried out.
Authors: Keiji Ogawa, Heisaburo Nakagawa, Toshiki Hirogaki, Eiichi Aoyama
Abstract: Fundamental characteristics in the micro drilling of carbon fiber reinforced plastic (CFRP) plates are investigated in the present paper. When micro drilling with a high-speed spindle, cutting forces during drilling, such as thrust force and torque, were measured by high resolution dynamometers and drill temperature was monitored by thermography. Comparing the experimental results of CFRP with that of drilling glass fiber-reinforced plastics (GFRP) revealed some unique tendencies. The cutting forces and drill temperature increased drastically. Moreover, drill wear rapidly accelerated. The tool life of CFRP plate drilling is much shorter than that of other plates.

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