• Title/Summary/Keyword: 플라스티신

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Experimental Investigation on the Flow Control in Non-Axisymmetric Flat Die Extrusion-1 (비축대칭 평금형 압출에서 유동제어에 관한 실험적 연구-I)

  • Bae, W.B.;Kim, Y.H.;Park, J.W.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.12
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    • pp.136-141
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    • 1996
  • In this paper, the design variables of the extruded parts involving flat die through model experiment are investigated to overcome some current problems such as bending and twisting and get more improved quality products. Above all, the deformation behavior is analyzed in experiment and investigated flow charactristics inside container. Finally, the straight extruded product is obtained by modified bearing land width on the basis of the exit velocities distribution from bended and twisted products.

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A study on rib-web shaped ring forging using UBET (UBET를 이용한 리브-웨브형 링 단조에 관한 연구)

  • Kim, Y.H.;Bae, W.B.;Nam, K.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.5
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    • pp.134-142
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    • 1994
  • An upper bound elemental technique (UBET) is applied to predict variations of neutral plane and optimal position of the initial billet for rib-wep shaped ring forging. In the analysis, the neutral plane position and velocity fields are determined by minimizing the total power consump- tion with respect to chosen parameters. The degree of die-cavity filling by initial billet-position and the variations of neutral plane by friction condition are investigated. Experiments have been carried out with pure plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agrement with the experimental results.

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A Study on the Process Design of Non-Axisymmetric Forging Components (비축대칭 형상의 단조 공정 설계에 관한 연구)

  • Kim, Y.H.;Bae, W.B.;Park, J.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.10
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    • pp.57-68
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    • 1995
  • An upper bound elemental technique (UBET) program has been developed to predict forging load, die-cavity filling, preform in non-axisymmetric forging. To analyze the process easily, it is suggested that the deformation is divided into two different parts. Those are axisymmetric part in corner, plane-strain part in lateral. The plane-strain and axisymmetric parts are combined by building block method. And the total energy is computed through combination of three deformation parts. A dumbbell-type preform has been obtained from height and volumetric compensations of the billet based on the backward simulation. Experimetns have been carried out with pure plasticine at room temperature. Theoretical predictions are in good agreement with expereimental results.

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A Study of the Torsional Forward Extrusion Using the Stream Function. (유선 함수를 이용한 비틀림 전방압출 공정에 관한 연구)

  • 이상인;김영호;이종헌
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.329-332
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    • 2002
  • The upper bound analysis by stream function is used to study the torsional forward extrusion. The torsional forward extrusion process not only reduces forming load but also increase optimal die angle. Optimal die angle is determined by the optimization technique. The advantages of this process are that the low capacity of pressing machine can be used and the process with a large die angle can be applied. To verify the theoretical result, we have carried out experiments using model material (plasticine) and FE simulations using DEFORM3D.

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A study on optimal design in axisymmetric forging processes using UBET (UBET를 이용한 축대칭 단조공정에서의 최적설계에 관한 연구)

  • 김영호;배원병;김진훈;김헌영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.5
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    • pp.1117-1125
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    • 1994
  • A UBET program is developed for determining the optimum sizes of preform of a rib-web part in axisymmetric closed-die forging. The program consists of forward and backward tracing processes. In forward process, material flow, degree of die filling, and forging load are predicted. In backward tracing process, the optimum dimensions of initial billet and preform are determined from the final-shape data without flash. The above program is easy to handle input data with and is convenient to visualize the whole process of closed-die forging with. Experiments are carried out with pure plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agreement with the experimental results.

Process Development of the Large-Size Dome Shaped Forging-Products Using the Incremental and Combined Forming Method (점진적 복합성형법을 이용한 대형 돔형 단조품의 공정개발)

  • 박치용;양동열;은일상
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.7
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    • pp.1685-1696
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    • 1994
  • In this paper, a new forming process of the large-size forgings within the limit of forming loads is developed by introducing the incremental forging method and combined forming method. For the development of the forming process, various related processes are proposed and modelling experiments of plasticine and corresponding numerical simulation ate carried out. Thus, an optimal process considering the productivity and economical efficiency is recommended from the study of formability and forming loads, etc. The selected process is subjected to a modelling experiment of lead and 1/7 scale prototype experiment of the real material so as to verify the effectiveness of a selected process as well as to determine the design parameters. The developed process is then applied the forging product of dome shape. Dome-shaped forgings can be produced by the developed process within the limit loads and with the simple tools.

A Study on Development of Model Materials Showing Similar Flow Characteristics of Hot Mild Steel at Various Temperatures (고온 연강 유동특성을 상사하는 모델재료 개발에 관한 연구)

  • 이종헌;김영호;배원병;이원화
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1161-1171
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    • 1993
  • Model materials are developed to achieve similarity of flow patterns for mild steels in forming processes at high temperatures. The model materials consist of pure plasticine and one or two additives such as resin and lanolin. To verify the similarity of flow patterns between physical modeling and compression of mild steels at high temperatures, ring and compression tests have been carried out with the developed-model materials at various strain rates, temperatures and lubricants. The test results are in good agreement with the flow patterns obtained from upsetting of a mild steel at high temperatures.