• Design & Manufacturing
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• 제14권2호
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• pp.49-55
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• 2020

Recently, when a new component of construction equipment is designed, a stamping process capable of producing parts having high appearance quality and precision has been gaining attention. However, in general, as it is developed based on existing parts made by welding metal sheets and tubes, frequent to die modification occurs, which increases the time and cost of developing new parts. Thus, it is necessary to reduce the cost by shortening the die development period. In this study, a stamping process was designed for the urea tank cover, which is a part for excavators, to reduce the die development period through sheet metal forming analysis. The stamping process was designed by determining the blank holding force after selecting the initial blank shape and size. The round value at the corner was modified such that formability is ensured. After selecting process parameters, the thickness reduction rate and spring-back effect were reviewed.

• 대한안전경영과학회지
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• 제20권4호
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• pp.1-6
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• 2018

Recently, bicycle has means of effective healthy transportation, and riding the bicycles is considered as popular recreational and sporting activities. Also, the saddle, steering system, driving device and braking device are researched briskly because of consumer's need for driving performance and comfort. Especially, the importance of a cassette responsible for transmission function by transmitting power to the drive shaft through the chain is very focused. The writer conducted structural analysis for the sprocket of each level using the ANSYS widely used for the analysis. Speed shifting performance was enhanced by minimization / simplification of shifting point through a sort of tooth profile of the cassette. By partitioning a clear value type and other shifting point, it has been modified to enable smooth speed-shifting. In addition, as titanium precision forming process, this study studied the molding technique by blanking and dies forging for mass production of the cassette. so it could be expected that the entire drive train would utilize that in the future. The stamping process capability for thin materials for the mass production of the sprockets is applicable to producing automobile parts, so lightweight component production is likely to be possible through that, for the safety of driving.

• Design & Manufacturing
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• 제16권4호
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• pp.40-45
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• 2022

The EV electric vehicle market is growing rapidly worldwide. An electric vehicle means a vehicle that uses energy charged through an electricity source as power. The precision of the press is important to mass-produce the drive motor, which is a key component of the electric vehicle. The size of the driving motor is increasing, and The size of the mold is also growing. In this study, the precision of large high-speed presses for mass production of driving motors was measured. A study was conducted on the measurement method of press and the analysis of measurement data. A drive motor is a component that transmits power by converting electrical energy into kinetic energy. EV driven motors have key material properties to improve efficiency. The material properties are the thickness of the material. As a method for improving performance, use a 0.2mm thin steel sheet. Mold is also becoming larger. As the mold grows, the size of the high-speed press for mass production of the driving motor is also increasing. Also, the precision of the press is the most important because it uses a thin iron plate material. So the importance of large press precision is being emphasized. In this study, the effect of large high-speed press structure on precision was verified

• 대한기계학회논문집A
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• 제35권9호
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• pp.1027-1033
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• 2011

VCM 강판은 용융아연도금강판 위에 PET/PVC 코팅하여 가전제품의 외판 소재로 사용되고 있다. 본 연구에서는 VCM 강판의 프레스 성형 중 발생하는 PET 코팅층의 찢김을 저감하기 위해 프레스 성형공정변수를 재설계하였다. 프레스 공정변수들이 PET 코팅층의 찢김에 미치는 영향을 분석하기 위해 유한요소해석을 수행하였다. PET 코팅의 찢김 현상은 드로잉 성형시 제품의 코너부 소재두께의 증가로 인해 금형과 소재 사이의 과도한 마찰에 의해 발생한다. 이를 해결하기 위해 블랭크 형상의 변경을 통해 드로잉성형시 코너부의 소재두께 증가를 저감하였으며, 트리밍 공정시 플랜지부의 과도한 두께 증가부분을 제거하여 플랜지 성형시 소재두께가 금형간극 이하로 분포하도록 하였다. 또한 성형실험과 유한요소해석을 통해 재설계된 공정변수들을 검증하였다. 이를 통해 PET 코팅의 찢김이 없는 양호한 최종제품의 성형이 가능함을 확인하였다.

• 한국기계가공학회지
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• 제11권1호
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• pp.101-106
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• 2012

The press bulging process is very useful and productive method to produce round-type mechanical components which have not been able to be manufactured because of limitation of the conventional press technology. The application of the press bulging process has expanded very quickly in the hydraulic and electronic industry and more recently it has been used to produce other mechanical parts such as the automobile and shipping parts. This expanding application also has brought some unsolved problems and leads many researchers to put their effort into the die design of the press bulging process. In this study, to obtain the optimum die shape for the press bulging process, various process parameters have been considered such as corner radius, bulging height, pressing length, and forming load, etc. The main interest of this paper is to verify the press bulging process which has more than 4.0 in height-length ratio. From this aspect, Finite Element analysis shows great ability to simulate the precise deformation process and gives us manufacturing database. Consideration of strain, stress, and strain-rate for the various cases has been also taken to keep the forming load within a particular range.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.979-983
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• 2007

본 논문에서는 액정용 실드 케이스 (Shield Case)의 스트립 레이아웃 도 작성하였다. 프레스 금형에 있어서 스트립 레이아웃 도는 제품 양산을 결정하는 중요 요인이다. 장착되는 다른 부품과의 간섭요인을 용이하게 수정하기 위하여 3D CAD/CAM 시스템을 적용하였다. 블랭크 레이아웃을 최적화하고 광폭배열로 스트립 레이아웃 하여 재료 이용률을 60.17%로 향상시켰다. 또한 얇은 소재두께로 인해 변형 발생이 예상되는 노칭부위에 집중적으로 비딩공정을 추가하여 제품의 평탄도를 요구사항에 맞게 적용하였다. 사용된 3D CAD/CAM 소프트웨어는 Unigraphics NX 3.0이며 12개 공정으로 스트립 레이아웃 도를 작성하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.698-701
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• 2005

Nowadays, because of the frequent market change and variable customer's requirements, product's life-circle is becoming shorter. So, automobile companies are forced to rapidly develop new products and efficiently reduce both manufacturing lead time and cost, with the world level quality. Among them, Press Die is not only just a bottle neck but also an important resource exerting certain effect in quality of car body appearance. Since 2000, due to efforts to reduce the time of design phase, many companies have used 3D design methods. Actually the method didn't reduce the period of design because the company didn't develop the best practice. This paper wish to solve this problem by modular based hybrid dies template.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1355-1360
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• 2007

The use of high strength steels are gradually increasing to reduce the weight of automobile to improve the environmental problems and collision safety. To encounter the traditional disadvantages of high strength steels like as a poor formability and high springback, hot press forming has been developed. By this method, the strength of steel sheet is increased about three times of original one through die quenching process. In order to the design of hot press forming tools by using numerical simulation, the knowledge of mechanical and microstructural characteristics are required. This study show the mechanical and microstructural characteristics of a high strength boron-alloyed steel according to the various quenching conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.349-353
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• 1993

공정게획은 일반적으로 숙련된 공정계획자에 의해 결정되는 데 공정계획자의 육성및 보급이 어려우므로 자동공정계획시스템의 필요성이 대두되었다. 지난 80년대에는 공정계획자의 지식에 의존한 공정계획의 알고리즘 개발에 치중하였지만 실용적인 측변에서 효율이 떨어지는 관계로 산업계에서 외면당하는 경우가 종종 발생하였다. 이러한 문제를 해결하고자 본 연구에서는 AutoCAD로 부터 자동 또는 대화식으로 부품의 형상 및 치수데이터를 인식하여, 이 데이터를 기준 으로 최적의 공구선정이 가능하게 데이터베이스를 구축하였다. 공작물의 크기에 따라 적절한 공작기계의 선정이 가능하도록 하였으며, 공구의 이동속도는 회귀분석방법에 의해 재질별로 구분하여 표준작업시간 계산규칙 및 알고리즘을 개발하였다

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 2부
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• pp.937-940
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• 2010

본 연구는 fine blanking 프레스로부터 기능면으로 사용되는 100% clean cut 전단면을 얻는 fine blanking 공정에서 die roll을 최소화하기 위한 목적으로 성형 해석 및 실험적 방법을 통해 die chamfer 형상에 따라 성형되는 제품의 die roll size 변화를 검토한 것이다. fine blanking 과정을 묘사하기 위하여 deform 2D를 이용하여 성형 해석을 수행하여 die roll size를 예측하였으며, 실제 die chamfer가 다른 die insert를 제작하여 fine blanking 실험을 실시하여 die chamfer 형상에 따른 die roll size에 대한 해석 data와 실험 data를 비교 분석하여 die roll 길이 방향 size의 경향을 파악할 수 있었다. 이 연구 결과는 fine blanking 판재 성형에서 die roll을 최소화하기 위한 die chamfer 설계에 유용하게 적용될 것으로 판단된다.