• Title/Summary/Keyword: Precision Cold

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An Automated Process Planning and Die design System for Bolt Products (볼트류 제품에 관한 공정설계 및 금형설계 자동화 시스템)

  • Song, S.W.;Choi, Y.;Jung, S.Y.;Kim, C.;Choi, J.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.774-777
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    • 2001
  • This paper describes a research work of developing a computer-aided design system of cold forging products. An approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from plastic theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoCAD with a personal computer and is composed of six modules, which are selection of billet material, input of final product, process planning design, preform modification, insert design, shrink rings design module. Based on knowledge-based rules, the system is designed by considering several factors such as volume constancy, limite of formability by material, preform shape and so on.

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Welding Characteristics of Cold Rolled Carbon Steel utilize CW Nd:YAG Laser (CW Nd:YAG 레이저를 이용한 냉연강판의 용접특성)

  • Shin B.H.;Yoo Y.T.;Shin H.J.;Ahn D.G.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.17-18
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    • 2006
  • Laser welding of metals has been widely used to improve a wear resistance and a corrosion resistance of the industrial parts. The objective of this research works is to investigate the influence of the process parameters, such as the welding for metals with CW Nd:YAG lasers. The bead-on-plate welding tests are carried out for several combinations of the experimental conditions. In order to quantitatively examine the characteristics of the butt welding, the welding quality of the cut section, stain-stress behavior and the hardness of the welded part are investigated. From the results of the investigation, it has been shown that the optimal welding condition without defects in the vicinity of the welded area and with a good welding quality is 1400W of the laser power, 0.8m/min, 0.9m/min of welding speed and $4{\ell}$ in of pressure for shielding gas.

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Effect of Cold Working on the Tensile Strength of Fe-26Mn-4Co-2Al Damping Alloy (Fe-26Mn-4Co-2Al 제진합금의 인장강도에 미치는 냉간가공의 영향)

  • Kang, Chang-Yong;Kim, Seong-Hwi;Jeong, Gyu-Seong
    • Journal of Power System Engineering
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    • v.20 no.6
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    • pp.46-50
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    • 2016
  • This study was carried out to investigate the effect of cold working on the tensile strength of Fe-26Mn-4Co-2Al damping alloy. ${\alpha}^{\prime}$ and ${\varepsilon}$-martensite were formed by cold working, and martensite was formed with the specific direction and surface relief. With the increasing degree of cold rolling, volume fraction of ${\alpha}^{\prime}$-martensite was increased, whereas the volume fraction of ${\varepsilon}$-martensite was decreased after rising to maximum value at specific lever of cold rolling. Tensile strength was linearly increased with an increasing of degree of cold rolling. Tensile strength was strongly affected to the volume fraction of ${\varepsilon}$-martensite formed by cold working, but the effect of volume fraction of ${\varepsilon}$-martensite on the tensile strength was not observed.

Precision Cold Forging of Spur Gear Using the Alloy Steel (합금강을 이용한 스퍼기어의 정밀 냉간 단조)

  • Choi, J.C.;Choi, Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.10a
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    • pp.172-175
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    • 1997
  • The conventional closed-die forgings had been applied to the forging of spur gears. But the forgings require high forging-pressure. In this paper, new precision forging technology have been developed. The developed technology is two steps forging process. Good shaped products are forged successfully with lower forging-pressure than those of conventional forging

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Analysis of Clinical Research Trends on Cold-Heat Pattern Identification in Korea - Focused on Quantitative Indicators for General People (한열변증의 국내 임상연구 동향 분석 - 일반인의 정량지표를 중심으로)

  • Yeo, Min Kyung;Lee, Young Seop
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.31 no.2
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    • pp.145-152
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    • 2017
  • The purpose of this study was to investigate the clinical research of Cold-Heat of pattern identification(PI) focused on quantitative indicators for general people in Korea, through the review of OASIS, KISS, DBpia, NDSL database. Ten clinical researches were analyzed in this study. These research gradually started from 2004 to 2009 but there was no research after 2010. Diagnosis of Cold-Heat PI all was done through a questionnaire, 7 or most researches had not used the intervention methods. Quantitative indicators related to the Cold-Heat PI mentioned in the selected 10 researches are seven, these indicators include heart rate variability(HRV), electroencephalogram, Yangdorak, respiratory index, electrogastrography, acoustic analysis index, western health test index. Related to the HRV were 3 researches, but correlation of significant indicators was a few levels(R=0.026-0.090). So far, studies regarding at the quantitative indicators of the prior the Cold-Heat PI were few, and the results of the study showed that low statistical precision, a lack of biological basis. Refer to the current state, in the future, we expect that research of quantitative indicators of scientific evidence-based through calculated and precise research concerning Cold-Heat PI be regarded as important in Korean Medicine.