• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.184-184
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• 2004

볼 나사는 반도체ㆍLCDㆍPDP 등 전자제품 조립장비 제조업체와 CNC 공작기계, 정밀측정기계, 직교좌표로봇, 반송장치, 항공기용 유압구동장치 대체품, 전동공구, 파워 steering, 테이블 개폐장치 등에서 구동 장치 및 물품의 이송을 위해 대부분 사용되는 중요한 기계요소 중의 하나이다. 그것은 회전운동을 직선운동으로 전환해주는 기구부에 들어가는 가장 중요한 부품이며, 원통형의 봉에 나선형의 그루브를 가공한 장축의 나사와 단축의 너트 사이에 볼을 게재시켜 축의 회전 시 적은 구름마찰로 인해, 너트부가 직선 운동하는데 원활 하게 만들어진 기계요소이다.(중략)

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1549-1554
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• 2010

Recently, plastic screws have replaced metal screws because of the former's light weight, thermal and electrical insulating properties, and anticorrosion characteristics. Plastic screws are usually produced by injection molding, which involves material shrinkage during the solidification of the polymer. This shrinkage results in the degeneration of the dimensional accuracy. In the present study, the effect of injection-molding conditions on the dimensional accuracy of plastic screws was investigated through a numerical simulation of injection molding; on the basis of this simulation, we could determine the mold-design parameters. The design of experiment was applied in accordance with the numerical analysis in order to optimize the injection-molding conditions with a view to improving the dimensional accuracy of the precision plastic screw.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.6
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• pp.503-507
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• 2015

In this study, we compare the performance of the screw through the Clamping force of the test materials to change shape and structure, one of the ways to maintain and improve the engaging force to cope with the miniaturization of the fastener threads are further thinner and lighter precision way that can improve the fastening force of the screw results were as follows. The clamping force according to the materials was $7.57N{\cdot}cm$ in SUS XM7 and SWCH18A was $5.97N{\cdot}cm$. This result was to be found to average 13.5% high in the Clamping force of SUS XM7 materials. In the case of the clamping force of the screw thread shape change, the clamping force of symmetrical and asymmetrical thread was $6.78N{\cdot}cm$ and $7.57N{\cdot}cm$. The clamping force of the asymmetrical thread showed an average high of 11.6%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.285-290
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• 1992

VTR(Video Tape Decoder) 데크(deck) 메카니즘의 조립과정중 최종공정인 주행계 조정공정은 비디오 테이프와 영상 헤드, 음성/콘트롤 헤드의 상대위치를 맞추는 공정으로 VTR의 화질을 좌우하게 된다. 본 연구에서는 주행계 조정나사들을 조정하는 나사조정장치와 이를 제어하여 VTR 데크 메카니즘의 주행계를 자동으로 조정하는 제어시스템을 설계, 제작하였다. 본 연구에서 개발된 VTR 데크메카니즘의 주행계 자동조정장치는 5개의 조정 나사를 모두 조정 가능하도록 구성되어 있기 때문에 시행착오로 인한 반복 조정 작업이 가능하게 되었다. 이것으로 공정의 합리화 및 자동화를 통한 공정의 무인화를 이루는 것이 본 연구의 목적이다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.292-292
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• 2004

치과용 임플란트(Implant)란 상실된 자연치아를 대신하여 골 내에 매식하는 인공치근을 말한다. 임플란트는 인접 자연치아의 보호, 심미적 안정 등의 장점으로 인해 그 수요가 늘어나고 있으며, 단일치아 임플란트의 경우, 부분 무치악 환자들에게 있어서 우수한 치의학적 해법이 되어왔다. 대부분의 임플란트는 두 개 이상의 구성요소로 이루어져 있으며, 각각의 구성요소는 나사에 의해 결합되어 있다. 많은 연구결과를 통해, 임플란트의 나사 풀림 현상(Screw loosening)은 임플란트와 관련하여 가장 흔한 문제로 나타나고 있다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.181-182
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• 2009

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.971-978
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• 2016

Recent trends in miniaturization and lightness in portable electronics parts have driven developments in subminiature screws. This study aims to investigate the thread rolling process of a subminiature screw with an outer diameter and pitch of 1.0 and 0.25 mm, respectively. Finite element (FE) analyses were performed for the thread rolling process of symmetric and asymmetric screw threads. Through FE analyses, various process parameters, such as the horizontal and vertical die gap and the rolling stroke, were investigated in terms of the forming accuracy. The material flow characteristics in the thread rolling process of the symmetric and asymmetric screws were also discussed, and the relevant process parameters were determined accordingly. These simulation results were then reflected on real thread rolling processes, from which the symmetric and asymmetric screws could be formed successfully with allowable dimensional accuracy.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.839-846
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• 2014

Recent trends in the miniaturization and weight reduction of portable electronic parts have driven the use of subminiature screws with a micrometer-scale pitch. As both screw length and pitch decrease in subminiature screws, the resulting clamping force becomes diminishes. In this work, Finite element (FE) analysis is performed to evaluate clamping force of a screw assembly, with a comparison with experimental result. To improve clamping force of subminiature screws, a new screw design is considered by modifying screw thread angle: the thread angle is varied as an asymmetric way unlike the conventional symmetric thread angle. FE analyses are then performed to compare the clamping characteristics of each subminiature screw with different thread angle. The effect of thread angles on the clamping force is then discussed in terms of structural safety for both positive and negative screws.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.821-822
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.743-744
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• 2012