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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Manufacturing Technology Engineers
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Journal DOI :
The Korean Society of Manufacturing Technology Engineers
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Volume & Issues
Volume 25, Issue 4 - Aug 2016
Volume 25, Issue 3 - Jun 2016
Volume 25, Issue 2 - Apr 2016
Volume 25, Issue 1 - Feb 2016
Selecting the target year
An Experimental Study for the Qualitative Effect of Carrier Pin Hole Position Error on Planet Load Sharing of Wind Turbine Three-point Suspension Gearbox
Nam, Ju-Seok ; Han, Jeong-Woo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 97~104
DOI : 10.7735/ksmte.2016.25.2.97
In this study, the qualitative effects of the positional error of carrier pin holes on the planet load sharing characteristics of the three-point suspension gearbox of wind turbines were investigated experimentally. A 35-kW gearbox comprising two planetary gear stages and a parallel gear stage and size one-fourth of that of a 2-MW three-point suspension gearbox was used as the test gearbox. The strain gauges attached to the ring gear teeth of the input planetary gear stage were used for the purpose of this study. The applied loading conditions were 50%, 75%, and 100% of the rated torque, and the mesh load factor was used as the load sharing index. The experimental results indicated that both the magnitude and direction of the positional error of pin holes had a significant effect on the planet load sharing characteristics of the three-point suspension gearbox. In addition, an increase in the applied torque results in uniform load sharing.
Temperature Distribution Analysis of Welding Parts in Ultrasonic Welding by Using FEM
Kang, Eun-Ji ; Min, Kyung-Tak ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 105~111
DOI : 10.7735/ksmte.2016.25.2.105
Ultrasonic metal welding, unlike the conventional welding techniques, does not require an external heat source, welding rod, or filler metal. Therefore, ultrasonic metal welding is not only economical but also environment-friendly, and hence, it has been receiving much attention. In ultrasonic welding, heat is generated because of the plastic deformation and the friction between both surfaces of the welded materials. It is important to identify the heat-affected zone by measuring the temperature generated at the weld. In this study, the effects of the welding pressure, welding time, and vibration amplitude on the temperature distribution in the weld were evaluated by performing a transient thermal analysis of the heat generated during ultrasonic metal welding. The experimental results indicated that the temperature of the weld tends to increase with the welding time and vibration amplitude. However, an increase in the pressure does not affect the temperature of the weld largely.
Performance Evaluation of Concrete Polishing Robot with Omnidirectional Mobile Mechanism
Cho, Gangik ; Chu, Baeksuk ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 112~117
DOI : 10.7735/ksmte.2016.25.2.112
In the construction industry, concrete polishing is used to grind and rub the surface of concrete grounds with polishing machines to increase the strength of the concrete after deposition. Polishing is performed manually in spite of the generation of dust and the requirement of frequent replacements of the polishing pad. The concrete polishing robot developed in this research is a novel polishing automation system for preventing the workers from being exposed to poor working environments. This robot is able to change multiple polishing tools automatically; however, the workers can conveniently replace the worn-out polishing pads with new ones. The mobile platform of the polishing robot employs omnidirectional wheels to enable a flexible motion even in small and complicated workspaces. To evaluate the performance of the developed concrete polishing robot, extensive experiments including square trajectory tracking, automatic tool changing, actual polishing, and path generation simulation were performed.
Characteristics of Abrasive Water Jet Milled Surface by Overlap Cutting
Park, Seung Sub ; Kim, Hwa Young ; Ahn, Jung Hwan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 118~123
DOI : 10.7735/ksmte.2016.25.2.118
Overlap cutting is a fundamental method of applying abrasive water jet (AWJ) machining to milling to produce a wider surface because the nozzle outlet is approximately 1.0 mm wide. In this study, the effects of overlap cutting on the depth profile and surface roughness are investigated. The overlapping area depends on the amount of step over, which is controlled in the pick-feed direction. If the step over is equal to or larger than the diameter of the nozzle, no overlap cut occurs but large cusps remain between the cut paths. A step over as small as one-thirds of the nozzle diameter may lead to triple-overlap cutting resulting in an extraordinary depth. By using pocket milling experiments with a step over of 0.46 (or 0.47), it is verified that AWJ can produce a milled surface of titanium, one of the hard-to-cut materials, with
Fine Dispensing Process of High Viscosity Phosphor for Repairing Application of White LED
Yang, Bong Su ; Yang, Young Jin ; Kim, Hyung Chan ; Ko, Jeong Beom ; Cho, Kyung Ho ; Doh, Yang Hoi ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 124~131
DOI : 10.7735/ksmte.2016.25.2.124
Several research works for finding and optimizing the methods of dispensing high viscosity phosphor used in the fabrication of white LED`s are currently in progress. High viscosity phosphor dispensing with a high accuracy is crucial because the dispensing rate and uniformity directly affect parameters such as the CIE chromaticity diagram, color temperature and luminous flux of white LED`s. This study presents a novel method of dispensing high viscosity phosphor using electrohydrodynamic printing. The dispensing rate was optimized less than 0.01 mg phosphor using experiments and optimizing the process parameters including the standoff distance from the nozzle to the substrate, ink supply pressure, and multi-step pulsed waveform magnitude ratio. The dispensing rate was measured by dispensing 20 dots using drop-on-demand with the optimized parameters, and the experiments were repeated 10 times to maximize the data accuracy. The average dispensing rate that can be reliably used for high viscosity phosphor dispensing was 0.0052 mg.
Robust Optimal Design of Tail Geometry for Stable Water-running Robots
Lee, DongGyu ; Jang, JaeHyung ; Seo, TaeWon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 132~137
DOI : 10.7735/ksmte.2016.25.2.132
Biomimetics involves the design of robotic platforms inspired from living creatures to achieve efficient operation under environmental conditions. A development within biomimetics involves investigating the function of a tail and applying it to robot design. This study aims to define the function of a static tail for water-running robots, and optimize its geometric and compliance parameters. The rolling angle of the tail is determined by the objective function, while the area and fillet ratio are used for geometric design and compliance parameters in the rolling and yawing directions. Repeated motion of the water-running robot`s footpads at frequencies of 9 and 10 Hz is used as the operating condition. Robust design based on the Taguchi methodology is performed via orthogonal arrays. The optimized tail design derived in this study will be implemented in a robotic platform to improve steering and balancing functions in the pitching direction.
Strength Analysis of Die-cast Aluminum-alloy Brake Pedals for use in Lightweight Cars
Cho, Seunghyun ; Jang, Junyoung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 138~142
DOI : 10.7735/ksmte.2016.25.2.138
In this study, a strength analysis was performed to assess die-cast aluminum alloy brake pedals as an improved alternative to wrought alloys. Aluminum brake pedal shapes are considered to be suitable for the die-casting process. The strength criterion of Volvo trucks was used as the criterion for the pedal strength. The results of this analysis showed that the frame thickness of the aluminum brake pedal must be increased from 12 mm to 18 mm to have a strength superior to that of a steel brake pedal. Additionally, the stress and weight of the aluminum brake pedal were found to be approximately 24% and 26% lower than those of the steel brake pedal, respectively. Mounting tests and strength assessments verified that the proposed die-cast aluminum alloy brake pedal demonstrated sufficient strength.
Tool Alignment and Machining Accuracy in Micro End Milling
An, Ju Eun ; Lee, Sung Ho ; Kwak, Jae Seob ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 143~148
DOI : 10.7735/ksmte.2016.25.2.143
A micro end mill is one of the precise tools used in machining ultra-precision products such as microchannel and micropatterned mold. To achieve the required precision of these products, several studies investigated the cutting force, burr formation, and burr generation mechanism of micro end mills; however, there are few studies on the alignment of micro tools, which is the foundation of machining. Hence, in this investigation, relation expressions were derived to determine the relation between the misalignment parameters and the machining accuracy. At the same time, the effect of the machining parameters was analyzed using a multiple linear regression analysis and the analysis of variance. The results indicate that the tilting angle of a micro tool has more influence on the machining accuracy than other parameters.
Development of Special Tool of Boom for Heavy Equipment
Jeong, Hwang-Young ; Song, Doo-Sang ; Hong, Jun-Hee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 25, issue 2, 2016, Pages 149~155
DOI : 10.7735/ksmte.2016.25.2.149
The purpose of this study is to develop special tools used to extend the tool life for the boom of heavy equipment. The boom of heavy equipment is manufactured by cutting the inner and outer surface with respect to the assembly site essential. In particular, when cutting the inner surface, entry of the tool is difficult owing to the limited size of the inner diameter and non circular cutting. In addition, the productivity is poor because the use of the cutting tool made of the SKH material. Therefore, it is necessary to develop a special tool for machining heavy equipment boom to extend tool life and to improve productivity. The special tool developed this study has the form of a holder and tip. The tip was created by applying a commercially available tungsten carbide insert.