http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
롤 다이 포밍에 의한 치형부품 제조 시 금형공차에 따른 성형성 평가
고대훈(Daehoon Ko),황성준(Sungjun Hwang),고대철(Daecheol Ko),이상곤(Sangkon Lee),권용남(Yongnam Kwon),이현석(HyunSuk Lee),박은수(Eunsoo Park) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
The roll die forming(RDF) process is new manufacturing technique for tooth parts such as drum clutch, hub clutch in vehicle transmission. The characteristic of RDF process is to deform the material using the installed roll in the die. The qualitative benefits obtained from RDF process are the increased productivity, reduced press load and increased dimension quality. In this paper, RDF process is applied to produce the hub clutch with tooth shape part. FE-simulation is conducted to confirm the metal flow according to process. Finally, the hub clutch as test product is manufactured by RDF process and comparison of dimension between test product and FE-simulation is good agreement.
DP980 트리밍 시 전단 각도에 따른 금형 수명에 관한 연구
최홍석(Hongseok Choi),고대철(Daecheol Ko),김병민(Byungmin Kim) 한국자동차공학회 2012 한국자동차공학회 지부 학술대회 논문집 Vol.2012 No.5-1
Ultra high strength steels such as DP980 are widely used in automotive industry for the light weight body. However, cutting tool life decreases due to their extremely high strength when trimming or blanking these steels. Trimming angle is importance parameter for the reduction of contact pressure on tool edge resulting in premature tool failure. In this study, the effect of trimming angle on the burr formation and sheared edge in trimming of DP980 sheet Trimming load and sheared edge with respect to the trimming angle are investigated using finite element analysis. Furthermore, tool life on the basis of burr height of 0.1mm is estimated using burr height diagram during 30,000 strokes by trimming experiment As a result of FE-analysis and experiment, trimming angle of -10° provide better influence on sheared edge, trimming load and trimming tool life.
단일겹치기이음시험을 이용한 합금화용융아연코팅강판의 코팅층 접합강도 평가
이정민(Jungmin Lee),이찬주(Chanjoo Lee),고대철(Daecheol Ko),이선봉(Seonbong Lee),김병민(Byungmin Kim) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.6
This paper was designed to estimate the adhesion strength of galvannealed coatings on steel sheets. The adhesion strength were evaluated using single lap - shear tests where the lap joint was bonded by structural adhesive. Tests were performed for overlap length of 5㎜, 10㎜ and 15 ㎜ and three directions (0, 45, 90) of steel sheets used as the adherend of the overlap joint. After the tests, FE simulations of the single lap - shear test were also carried out to observe the stress distribution in the interface between the adhesive and the coated sheet. The results showed that the joint failure loads obtained from the tensile tests of bonded single lap-joints were the same, regardless of overlap lengths and directions of steel sheets. Also, the failure of galvannealed coatings greatly depended on shear stress distribution in the interface and the value was about 30㎫.
합금화용융아연코팅강판의 코팅층 접합강도 평가를 위한 단일 겹치기이음 시험의 적용
이정민(Lee Jungmin),이찬주(Lee Chajoo),이상곤(Lee Sanggon),고대철(Ko Daecheol),김병민(Kim Byungmin) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5
This paper is designed to estimate the adhesion strength of coating layer on galvannealed steel sheet using lap shear test. The single lap shear test is the most commonly used standard test for determining the strength of medium-strength and high strength bonds. The bond strength of bonded single lap joints on subjecting the substrates to loads is determined by lap shear forces in the direction of the bonded joint. In this study, specimen for adhesion strength test was made to attach coated sheet to cold rolled sheet and were heated in temperature of 180 for 20minutes. After test, detached parts of coatings on coated sheet were observed using SEM and EDX to identify substrate and complete detachment. The tested results showed that adhesive strength of coating is unrelated to anisotropy of sheet and is difficult to be extracted using conventional theory because of fine cracks of coating layers which were created during annealing process.