• 동력기계공학회지
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• 제8권3호
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• pp.23-29
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• 2004

In this paper, a finite element formulation using dynamic-explicit time integration scheme is used for numerical analysis of Hydro-forming processes. The lumping scheme is employed for the diagonal mass matrix and dynamic explicit formulation. Hydro-forming process for auto-body panel forming is analyzed by using dynamic-explicit finite element method. Further, the simulated results of the Hydro-forming processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

• 한국기계가공학회지
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• 제10권5호
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• pp.72-78
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• 2011

Currently, for the damper case, the material produced by cast/forge welding is mechanically processed and then the final product is mass-produced. By cutting the cast/forge welded material, the issues of excessive cutting time, multiple process production, and a large amount of chips (40% loss from the original material) arise, causing increased production cost and reduced profitability. Thus, in this study, the incremental forming technology which generates no chips was applied in production. Analysis was excuted for 1st and 2nd works by change of tool diameter and working tool. For this, 3D molding and analysis were executed, which was applied to the processing the result, successful processing could be achieved through a few trials of molding processing according to tool forming and rotation counts.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.320-323
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• 2002

This paper discusses process design of cold forging for inner tooth part, drum clutch. In respect to high productivity, low material consumption and low piece production costs, Metal forming has more merits than machining process. Net shape forming is huh technology which satisfies merits of metal forming and achieves high accuracy. Recently, net shape forming method widely applied because of high productivity, low material consumption and low piece production costs using press. In this study, the method which accuracy of drum clutch, automatic transmission pin, can be improved is discussed. First, process variables for process design of drum clutch are selected, and then process design is accomplished using forming analysis method. from forming analysis, forming load, stress, unfiling part is obtained. and comparing these results, optimal process design can be determined.

• 소성∙가공
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• 제10권1호
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• pp.59-66
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• 2001

Recently, the technology of incremental forming for sheet metal components has drawn attention for small-batch productions. In the present investigation, a forming tool containing a freely-rotating ball was developed and applied to forming of various shapes with full annealed Al 1050 sheet. Deformation characteristics occurring during forming with this tool was examined through FEM analysis and grid measurement. It was found that deformation modes developed along a straight path and around a corner are close to those of plane-strain and equi-biaxial stretching, respectively, and that cracks occur mostly at corners for the same depth of tool. FEM analysis was successfully applied to this special type of forming process and provided comparable results to the measurements from experiment.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제26회 춘계학술대회논문집
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• pp.379-382
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• 2006

두께가 얇고 길이가 긴 튜브 제품을 생산하기 위한 방법으로 유동성형 공정이 많이 이용되고 있으며 이는 다른 가공방법에 비해 성형력이 작고 유동성형에 의해 가공된 제품의 기계적인 강도가 우수하며 가공 후 표면 품질이 좋기 때문이다. 특히 유동성형은 로켓 모터 케이스, 연소기, 유압 실린더 그리고 고압용기 등과 같은 고정밀도의 두께가 얇은 실린더 제품을 생산하기 위한 적합한 공정이다. 본 논문에서는 3개의 롤러를 가지는 전후방 유동성형에 대한 유한요소해석을 통해 가공깊이와 가공속도가 성형력에 미치는 영향을 살펴보았다. 다양한 가공깊이와 가공속도 조건에서 얻어진 전후방 유동성형에서의 축방향과 반경방향의 성형력을 비교하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.251-254
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• 2005

The flow forming has been used to produce long thin walled tube parts, with reduced forming load and enhanced mechanical and surface quality for a good finished part compared with other method formed parts. So flow forming technique is used widely in industrial production. Especially spinning and flow farming techniques an used frequently in automotive, aerial, defense industry. In this paper, FEM analysis of three-roller backward flow forming of a workpiece is carried out to study effects of forming depth and feed rate on forming force. The axial and radial forces on several forming depth and feed rate conditions are obtained. The phenomena such as bell mouth, build up and bulging during simulation are observed as well.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 제2회 박판성형심포지엄 논문집 박판성형기술의 현재와 미래
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• pp.83-94
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• 1998

An analysis system for sheet metal forming has been developed to improve the design and tryout process by predicting the deformation behaviour more precisely. This analysis system consists of forming analysis, springback analysis and post processor modules. The more accurate prediction of stress history can be achived due to the improved contact algorithm. Successive simulation of several processes can be carried out conveniently without interrupt by the improved data management of the developed system. The error of data transfer between forming analysis and springback analysis is minimized using the proper shell element. Several benchmark test results and practical results are presented to show the effectiveness and reliability of this program.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1313-1314
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• 2011

• 한국산학기술학회논문지
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• 제19권9호
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• pp.1-6
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• 2018

하이드로포밍 기술은 지난 20년간 자동차부품의 적용을 중심으로 비약적인 발전을 해 왔다. 이 기술은 자동차 산업응용분야에 많은 장점을 가지고 있는데 이는 더 나은 구조적 강건성, 부품수 감소에 기인한 비용절감, 재료절약, 무게감소, 낮은 스프링백현상, 개선된 강도, 내구성 향상, 설계 유연성 등이다. 하이드로포밍 부품의 성형성 검토를 위하여 다양한 컴퓨터 시뮬레이션 기술 등이 발달해 왔으며 이를 통해 성형 가능성을 검토하는 것과 동시에 성형을 위하여 벤딩 공정, 프리포밍공정, 다이클로징 공정 등의 효율적인 공정을 수립하여 하이드로포밍 부품들을 설계하고 있다. 이에 본 연구에서는 하이드로포밍 부품 설계 시 고려사항 중 성형량, 부품의 단면길이(하이드로포밍 프레스 용량에 맞는), 최소 곡률(하이드로포밍 압력에 따른 곡률 영향 평가) 등을 제시하고 실제 자동차용 리어 서브-프레임 부품의 단면분석을 실시함으로써 하이드로포밍 성형을 위한 설계 방안을 제시하고자 한다. 아울러 하이드로포밍 공정인자 중 프리벤딩, 축피딩, 유압 압력, 프레스 하중, 마찰 등의 효과를 분석하여 이들 공정이 직접적인 하이드로포밍 성형에 필요인자 인지 등을 고찰하였다.

• 한국기계가공학회지
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• 제14권4호
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• pp.118-125
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• 2015

The roll-forming process is a highly productive incremental forming process and is suitable for manufacturing thin, high-strength steel products. Recently, this process has been considered one of the most productive processes in manufacturing high-strength steel automotive structural parts. However, it is very difficult to develop the roll-forming process when the cross-sectional shape of the product changes in the longitudinal direction. In this study, a roll-forming process for manufacturing high-strength steel automotive parts with a linearly variable symmetric hat-type cross-section was developed. The forming rolls were designed by the 3D CAD system, CATIA. Additionally, the designed forming rolls were modified by the simulation through the 3D elastic-plastic finite element analysis software, MARC. The results of the finite element analysis show that the final roll-forming roll can successfully produce the desired high-strength steel automotive part with a variable cross-section.