• Title/Summary/Keyword: Shape Fixability

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A Study on Shape Fixability of Press Formed Parts (판재 프레스 성형 제품의 형상동결성 연구)

  • 한수식;박기철;남재복
    • Transactions of Materials Processing
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    • v.8 no.1
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    • pp.38-46
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    • 1999
  • This paper deals with the shape fixability of press formed parts through the use of a V-bending process and a U-bending one. The influence of material properties on the shape fixability in forming processes was investigated. A V-bending process had on optimum ben radius for each combination of parameters which caused maximum shape fixability. In the U-bending process the blank holder force could control the degree of shape fixability. A ha호 blank holding force resulted in a uniform strain distribution and increased shape fixability.

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Development of Automotive Seat Rail Parts for Improving Shape Fixability of Ultra High Strength Steel of 980MPa (980MPa 초고장력 강판의 형상 동결성 향상을 통한 자동차 시트레일 부품 개발)

  • Park, Dong-Hwan;Kwon, Hyuk-Hong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.5
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    • pp.137-144
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    • 2016
  • This paper aims to ensure describe the a spring-back prevention technique for improving shape fixability by using an ultra-high strength steel sheet with 980 MPa to develop a lightweight seat rail parts. Ultra-high strength steel gives a potential for considerable weight reduction and a cost-effective way to produce energy efficient vehicles. The influence of a spring-back of seat rail parts on the shape fixability in forming processes was investigated to be solved by an adjustment of the appropriate tool design and process parameters. The computed results for improving shape fixability were in good agreement with the experimental results.

Press Formabilities of Aluminum Sheets for Autobody Application (차체용 알루미늄 판재의 프레스 성형성)

  • Kim, Y.S.;Kim, K.S.;Kwon, N.C.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.1
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    • pp.73-83
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    • 1994
  • Press formabilities of aluminum sheets for automobile body were investigated. Plane strain stretching test (called RIST-PSST), cupping test and U bending test were performed to assess the press formability of aluminum sheets respectively. The results showed that aluminum sheets are generally inferior to cold-rolled steel sheet of deep drawing quality (CSP3N) in press formability. The limiting punch height (LPH) and limiting plane strain (FLCo) of aluminum sheets are 50%-70% level compared to that of CSP3N. Moreover, the limiting drawing ratios(LDR) of aluminum sheets are ranged between 1.95 and 2.1. The poor press formability of aluminum sheets is responsible for low values of total elongation and plastic anisotropy parameter in tensile characteristic. The shape fixability of aluminum sheets evaluated in U bending test is very poor due to its low elastic modulus compared to CSP3N.

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A Study on the Springback Characteristics and Bracket Formabilities Enhancement of Aluminum Alloy Sheets for Autobody Application (차체용 알루미늄합금 판재의 스프링백 특성과 브래킷 성형성 향상에 관한 연구)

  • 최문일;강성수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.6
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    • pp.64-76
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    • 1997
  • This paper deals with development of brackets by using aluminum alloy sheets which is indispensable for weight reduction of autobody. The press formability of aluminum alloy sheet is estimated by means of tensile test, V bending test, sample manufacturing test and photograph of microstructure. The results show that the elongation, strength, work hardening exponent, plastic anisotropy coefficient of Al 6***series are better than those of Al 5***series, but for general press formability, Al 5***series are better than Al 6***series due to lower yield strength. Since most of mechanical properties of aluminum sheet are generally inferior to those of cold-rolled steel sheet, shape fixability and press formability of aluminum sheet are very poor. For making components of autobody by use of die for steel sheet application, it is essential that die should be nodified for least bending and stretching. With the modified die for aluminum, it could be possible to make brackets, the component of autobody. Microstructure of Al 5***series has fine grain and small the 2nd phase and that of Al 6***series has relatively coarse grain. Therefore, it seems that fine grain and small the 2nd phase of Al 5***series is one of the factor of lower yield strength, resistance to stamping work, formation of Luder's line.

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Dynamic Mechanical Interpretations of Shape Memory Behavior (형상기억 거동의 동적 기계적 해석)

  • 이상엽
    • The Korean Journal of Rheology
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    • v.9 no.1
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    • pp.33-39
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    • 1997
  • PCL, MDI, BD 및 DMPA를 이용, 폴리우레탄(PU)을 ionomer 및 nonionomergudxo 로 제조하였으며 이때 연질성분의 함량(SSC) 및 길이가 PU의 기계적, 동적기계적 특성은 물론 형상기억특성에 미치는 영향을 연구하였다. Ionomer는 nonionomer에 비하여 경도, 탄 성율 및 강도가 모두 우수하였으며 그 효과는 실온에서 경질성분의 함량(HSC)이 높은 PU 일수록 보다 뚜렷하였는데 이는 HSC가 증가할수록 ion 중심의 농도가 증가하며 ion 중심간 의 Coulob 력이 고온보다 실온에서 보다 큰데 기인하는 것으로 해석하였다. 반복인장하중실 험에서 ionomer는 nonionomer에 비해 회복변형이 크고 잔류변형이 작았는데 이는 ionomer 의 고무탄성율이 보다 큰 데 기인한 것으로 해석하였다. 나아가 재료의 형상기억거동은 기 본적으로 탄성율의 온도의존성에 크게 의존함을 알수있었다.

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The Prediction of Defection for the Shape Fixability on the Stamped Lead Frame (반도체 리드프레임의 형상 동결성에 관한 연구)

  • Cho H. K.;Kim D. H.;Lee S. B.;Kim B. M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.77-80
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    • 2001
  • IC lead frame needs the precision shape for good efficiency. In the blanking process, there are many parameter effected the dimensional accuracy : lead width, blanking order, striper force, tool clearance etc. In this research, the4 undesirable defects appeared in the final blanking process. so we measured the deflection of lead according to the stripper force using $PAM-STAMP_{TM}$. In the result, the deflection was decreased by increasing the stripper force properly. and we changed the blanking order on the test model. In the blanking order, deflection is good from the outer line position blanking to center line position. so we can design the precision die without tryout by the prediction of the lead deflection.

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Process Design of Automobile Seat Rail Lower Parts using Ultra-High Strength, DP980 Steel (980MPa급 초고장력 강판을 이용한 자동차용 시트 레일 로어 부품의 성형공정 설계)

  • Park, Dong-Hwan;Tak, Yun-Hak;Kwon, Hyuk-Hong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.2
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    • pp.160-167
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    • 2018
  • The purpose of this study is to develop a process for forming a MPa ultra-high strength steel sheet to reduce weight and improve product strength. To do this, we performed the initial process design based on empirical formulas in a handbook and experience of skilled engineers, and researched the effects of major process variables on spring back by analyzing the forming analysis and experimental results. This paper suggests an optimal process design of the seat rail lower parts, using a MPa ultra-high strength steel sheet. This satisfies the dimensional accuracy and strength requirements for the product.

Development of tube hydroforming technology (관재의 하이드로 포밍 기술개발)

  • 이택근
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.30.2-34
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    • 1999
  • The hydroforming technology has gained in importance over the last few years, because of its potential for substantial weight avings costs reduction and quality improvement such as collision property, shape fixability and rigidity of white body. However, in comparison with the traditional sheet forming process, the hydroforming is much younger and the main development efforts were made in the last 15 years. The new technology, high pressure tublar hydroforming in particular, involves many process parameters to be optimized. This paper covers a brief overview of the hydroforming simulator as well as design of die and tools. The effects of typical parameters such as internal pressure and axial compression stroke are presented. Moreover, the conditions of forming failure occurrences such as fracture and wrinkle are examinated.

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