• 소성∙가공
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• 제17권4호
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• pp.278-283
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• 2008

This paper concerns the die face design for a heat protect panel aided by the finite element forming analysis in order to eliminate the surface defect and to improve the surface quality. The CAE procedure of the stamping process is introduced in order to reveal the reason of surface inferiorities and to improve surface quality. Complicated shape of the product induces the surface inferiorities such as wrinkling due to the insufficient restraining force of the forming blank and the non-uniform contact of the blank with the tools. This paper proposes a new guideline for the die design which includes the modification of tool shapes and addition of the draw-beads on the tool surface for ensuring the increased the restraining force with the uniform contact condition. The effectiveness of the proposed design is verified by the forming analysis and is confirmed by the tryout operation in the press shop. The analysis and test results show that the modified process parameters such as tool shapes and draw-beads can reduce the tendency of wrinkling and improve surface quality.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.114-118
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• 1996

Evaluation of cutting condition is one of the most important aspect to improve productivity and quality. In this study, the wear and cutting characteristics(cutting force, acoustic emission signal and surface roughness) of ceramic cutting tool for hardened die material(SKD11) were investigated by experiment. Flank wear on relief face of tool was occurred more dominant than crater wear on rake face. Experiments were performed under the various cutting condition.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.675-681
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• 2002

Parametric modeling and configuration design method are a important methods for rapid design in manufacturing. This paper proposes a relation rules which parametrically models a bonnet trimming tool based on Pro/Engineer. The concept of desogn is applied a trimming die of the bonnet outer panel. Trimming die have a many parameters. Each a parameter is related the die face and punch profile. A design system consists of a Pro/Engineer, a Pro/program.

• 마이크로전자및패키징학회지
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• 제23권2호
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• pp.79-84
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• 2016

유연전자소자가 외부힘에 의해 변형될 경우 반도체 다이가 기계적 응력 때문에 변형되거나 파괴되고 이러한 변형이나 파괴는 channel의 전자이동도를 변화시키거나 배선의 저항을 증가시켜 집적회로의 동작 오류를 발생시킨다. 따라서 반도체 집적회로는 굽힘 변형이 발생해도 기계적 응력이 발생하지 않는 중립축에 위치하는 것이 바람직하다. 본 연구에서는 굽힘변형을 하는 flip-chip 접합공정이 적용된 face-down flexible packaging system에서 중립축의 위치와 파괴 모드를 조사하였고 반도체 집적회로와 집중응력이 발생한 곳의 응력을 감소시킬 수 있는 방법을 제시하였다. 이를 위해, 설계인자로 유연기판의 두께 및 소재, 반도체 다이의 두께를 고려하였고 설계인자가 중립축의 위치에 미치는 영향을 조사한 결과 유연기판의 두께가 중립축의 위치를 조절하는데 유용한 설계인자임을 알 수 있었다. 3차원 모델을 이용한 유한요소해석 결과 반도체 다이와 유연기판 사이의 Cu bump 접합부에서 항복응력보다 높은 응력이 인가될 수 있음을 확인하였다. 마지막으로 flexible face-down packaging system에서 반도체 다이와 Cu bump 의 응력을 감소시킬 수 있는 설계 방법을 제안하였다.

• 소성∙가공
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• 제14권9호통권81호
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• pp.772-778
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• 2005

This paper is concerned with the analysis of material flow characteristics of combined tube extrusion using pipe. The analysis in this paper concentrated on the evaluation of the design parameters for deformation patterns of tube forming, load characteristics, extruded length, and die pressure. The design factors such as punch nose radius, die corner radius, friction factor, and punch face angle are involved in the simulation. The combined tube extrusion is analyzed by using a commercial finite element code. This simulation makes use of pipe material and punch geometry on the basis of punch geometry recommended by International Cold Forging Group. Deformation patterns and its characteristics in combined forward and backward tube extrusion process were analyzed for forming loads with primary parameters, which are various punch nose radius relative to backward tube thickness. The results from the simulation show the flow modes of pipe workpiece and the die pressure at the contact surface between pipe workpiece and punch. The specific backward tube thickness and punch nose radius have an effect on extruded length in combined extrusion. The combined one step forward and backward extrusion is compared with the two step extrusion fer forming load and die pressure.

• Design & Manufacturing
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• 제6권2호
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• pp.37-41
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• 2012

Usually compound dies are used in clinch washer production. However, in this study, a fine blanking die is designed and manufactured, and clinch washers are produced by the die. Clinch washers are for electric exhaust gas recirculation (EEGR) and they recirculate some of exhaust gas to reduce harmful substances. Fine blanking automation production eliminates difficulties operators face on conventional press.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.29-29
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• 2005

• 한국독어학회지:독어학
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• 제10집
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• pp.175-200
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• 2004

Bei verschiedenen $Gespr\"{a}chen$ zwischen Frauen und $M\"{a}nnern$ sind mehrere Unterschiede in $Gespr\"{a}chsstrategien$ und -verhalten des jeweiligen Geschlechts zu beobachten. Herkemmlichen Ansichten nach $f\"{u}hrten$ $M\"{a}inner$ $Gespr\"{a}iche$ mit Frauen eher dominativ, $w\"{a}hrend$ Frauen eine deutliche Vorliebe $f\"{u}r$ kooperativ erlaufende $Gespr\"{a}che$ zeigen. Um die $G\"{u}ltigkeit$ dieser Perspektive zu $pr\"{u}fen$, wurden in dieser Albeit insgesamt $zw\"{o}lf$ Beratungsgesprache herangezogen. Daraus ergab sich, dass $M\"{a}nner$ im $Gespr\"{a}ich$ statistisch $h\"{a}ufiger$ die anderen $Gespr\"{a}chsteilnehmer$ unterbrechen. Da ein $Gespr\"{a}ch$ ein komplex vernetztes soziales Geschehen ist, sollte diese Statistik bei der Bestimmung der $Gespr\"{a}chsverhalten$ von zwei Geschiechtern keine entscheidende Rolle spielen. Im Anschluss daran habe ich mick mit Hilfe einiger im Internet gesammelten Daten, mit den $Gesp\"{a}chsverhalten$ bei der so genannten Online-Kommunikation befasst. Bei der Online-Kommunikation lassen sich zwei kontrastive verbale $Umg\"{a}nge$ der Geschlechtern beobachten, $n\"{a}mlich$ ein reibungslos ablaufendes IRC(Internet Relay Chatting) und eine $auff\"{a}llige$ Debatte, die mehrfache Konflikte zwischen den Beteiligten zeigt. Um diese $Ph\"{a}nomene$ auf der Basis der $Gespr\"{a}chsanalyse$ zu $erl\"{a}utern$, werden vol allem das Konzept der Kooperation beim $Gespr\"{a}ch$ und die Dynamik der $Gespr\"{a}chsstruktur$ erneut begriffen. $Schlie{\ss}lich$ werden die unterschiedlichen $Gespr\"{a}chsverhalten$ von Frauen und $M\"{a}nnern$ folgend wiedergegeben: Bei realen Face-To-Face-$Gespr\"{a}chen$ setzen Frauen den Schwerpunkt auf die emotionale und interaktive Kooperation, $w\"{a}hrend$ Manner ihn auf die kognitive Kooperation setzen. Dieser Sachverhait $\"{a}ndert$ sich aber bei der Online-Kommunikation. Auch Manner halten die emotionale und interaktive Kooperation $f\"{u}r$ wichtig und $f\"{u}hren$ mehr kooperative und reibungslose $Gespr\"{a}iche$ mit Frauen. Doch in einer Debatte um ein Thema $verh\"{a}lt$ sich jeder Beteiligte anders. Die moisten benutzen die Strategien, die den geringen Unterschied zwischen den Geschlechtern in Anfangsbedingungen $vergr\"{o}{\ss}ern$, und gleichzeitig die individuellen Unterschiede zwischen demselben Geschiecht verschleichen. Dadurch kann eine Debatte zwischen Geschlechten in Streit ohne Kompromisse geraten.

• 한국기계가공학회지
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• 제19권5호
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• pp.91-97
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• 2020

A split-die design for the cold forging of symmetric parts such as those having a hexagonal cross-section is presented in this paper. Parts with a hexagonal cross-section, such as bolt heads and nuts, should be forged with a die that has a hexagonal-shaped hole. A split type die is required to mitigate the buildup of stress concentrations located at the corners of the hexagonal hole. Generally, the insert of a hexagonal die is made by cutting each corner of a cylinder using a hexagonal hole and then combined with the die and shrink-fitted. However, split dies face problems when extruding material at the corners of the hexagonal split die. To address this problem, two types of split dies were evaluated: rounded hexagonal dies and angular hexagonal dies. The effects of the pre-stress ring on the dies were compared and analyzed and results show that using the angular split hexagonal die can extend the lifetime of forging dies.

• 소성∙가공
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• 제24권6호
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• pp.400-404
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• 2015

For mass production of stamped parts, which require complicated in-press operations, it is always advisable to use a progressive die set. It is difficult to choose a progressive die set if the stamped parts need to be deep drawn and especially if they are unsymmetrical. Because unsymmetrical deep drawing parts are very sensitive to the effect of weight during moving to the next step, they are hard to exactly locate on the die face. An automotive seat side cushion panel is about 80mm high, unsymmetrical and its low edge needs hemming, so it is hard to produce even using a progressive die set. In the current paper a progressive stamping for seat side cushion panel was examined. Five strip bridges were considered to be strong enough to move to the next die as predicted by the CAE analysis.