• KCID journal
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• v.11 no.1
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• pp.106-112
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• 2004

• The monthly packaging world
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• s.249
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• pp.84-87
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• 2014

• Review of Korean Society for Internet Information
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• v.14 no.4
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• pp.40-44
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• 2013

• Electric Engineers Magazine
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• s.359
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• pp.42-43
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• 2012

• The monthly packaging world
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• s.324
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• pp.68-72
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• 2020

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.68-74
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• 2001

In the drawing of large size automotive panels, elastic deflection of die components is induced by the contact force between them. The deflection is nonuniform and locally distributed, and results in nonuniform material flow. In order to arrange such a nonuniform die gap, a correcting operation, so called die spotting, is inevitable, which requires trial and error works and consuming time. A prediction of the bending deflection prior to a try-out must be useful to reduce the die spotting time. In this study, drawing process of a front fender is simulated first. and the deflection of the blank holder is calculated from the contact force imposing on th blank holder. The balance block heights ensuring a uniform deflection are optimized by the analysis and design of experiments.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.164-170
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• 2003

To ensure the reliability of DVDR-P and DVD-ROM, it is imperative to remedy the unrecoverable creep deformation and/or relaxation of the holding force of an optical disc holder. To predict the deformation of an optical disc holder, a deformation analysis of an 80 mm optical disc holder considering the creep characteristics of 3 plastic materials has been conducted. Subsequently, the results by this Finite Element Analysis (FEA) are experimentally verified. A disc holder inserted in a cartridge case is kept in a chamber of $60^{\circ}C$ with 90 % humidity for 24 hours. The arm span and the holding force of the disc holder are measured after being left for another 24 successive hours at a room temperature and under normal humidity. The predicted results by FEA are in good agreement with experimentally measured values.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.363-366
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• 2003

The hard turning is a turning operation performed in high strength alloy steels (HRC>30) in order to reach surface roughness close to those obtained in grinding. This is possible because of availability of improved tool materials (polycrystalline cubic boron nitride. PCBN), ad more rigid machine tools. According to many previous work of hard turning mechanism, the maximum temperature of cutting can be raised up to 100$0^{\circ}C$. As the heat generation rate is very high, the thermal displacement of tool holder cannot be negligible. Therefore, the aim of this paper is to analyze effects of high heat generation at CBN tool tip to the thermal displacement of a tool holder in hard turning and finally geometric accuracy. The thermal behavior of a CBN tool holder is investigated by numerical simulation and experiment, and the result shows thermal elongation of microns order is possible during hard turning process.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.790-796
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• 2012

Chip curling occurred during cutting process for difficult-to-cut material detracts product qualities and productivity. Among of method preventing the phenomenon, high pressure injecting cutting oil is an alterative. In this study, the optimal nozzle was designed by CFD method and it was conducted to analyse on the effect of high pressure injection on chip shape generated during cutting process and wear of insert by experimental method. As the result, it could be confirmed that high pressure injection is favorable for preventing chip curling and insert from wearing.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.159-164
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• 2000

In this study, the deformation analysis of 80mm optical disk holder considering the creep characteristics of plastic materials has been conducted and experimentally verified. It is very important to remedy the unrecoverable creep deformation and relaxation of holding force of an optical disk holder for the reliability of DVDR-P, DVD-ROM. A disk holder inserted in a cartridge case has been kept in the chamber with $60^{\circ}C$ temperature and 90% humidity for 24 hours. After storage test, the arm span and holding force of a disk holder have been measured after 24 hours at room temperature and normal humidity. The predicted results are in good agreement with experimentally measured one.