• Title/Summary/Keyword: Preform design

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Design Methodology of Preform for Reducing Tool Wear in Cold Forging (냉간 단조 금형의 마멸 감소를 위한 예비성형체 설계방법)

  • 이진호;김태형;김병민
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.4
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    • pp.118-124
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    • 1998
  • The die wear is one of the main factors affecting die accuracy and tool lifetime. It is desired to reduce die wear by developing simulation method to predict wear based on process variables, and then optimizing the process. Therefore, this paper describes methodology of preform design for minimizing wear of finisher die in multi-stage cold forging processes. The finite element method is combined with the routine of wear prediction. The cold forging process is analyzed using developed simulation method. In order to obtain preform to minimize die wear, the Flexible Polyhedron Search(FPS) algorithm is used. The optimal preform shape is found from iterative deformation analysis and wear calculation.

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Process Design in Shell Nosing for Net-Shape Product by the Backward Tracing Schme of the Rigid-Plastic FEM (유한요소법의 역추적기법을 활용한 정밀정형 노우징 부품의 성형 공정설계)

  • 김상현;이진희;강범수
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1995.03a
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    • pp.224-232
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    • 1995
  • A process is designed by the backward tracing scheme of the rigid-plastic FEm for net-shape shell nosing component without machining after forming. The current process of the shell nosing industry requires cost-consuming machining to produce final product . The backward tracing scheme of the rigid-plastic FEM, a novel method in preform design of metal forming processes , derives a sound preform for net-shape shell nosing product . The current process is simulated to check the metal flow involved informing with a trial preform and its modified preform. It is found that the two preforms are not suitable for net-shape shell nosing product. Finally, a preform is desinged by the backward tracing scheme, which is suitable for net-shape manufacturing of the shell nosing component.

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Development of Die Design System for Turbine Blade Forging (터빈 블레이드의 형단조 금형설계 시스템 개발)

  • 조종래
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.77-81
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    • 1999
  • The predictions of metal flow forging load optimal die angle and preform size are not so easy in turbine blade forging. First of all the quality of final product is influenced by side force which is one of the significant factors. in this study slab method is applied to determine optimal die angle minimizing side force and the position of preform Finally drawing of die design is obtained in optimal die angle with developing tool that is composed of Visual Basic.

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Process Development to Form Net-Shape Nosing Shells by the Backward Tracing Scheme of the Rigid-Plastic FEM and Its Experimental Confirmation (강-소성 유한요소법의 역추적기법을 이용한 정밀정형 쉘 노우징 부품의 성형공정 개발과 실험적 증명)

  • Kim, Sang-Hyeon;Lee, Jin-Hui;Im, Hak-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.7
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    • pp.2118-2133
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    • 1996
  • A preform is designed by the backward tracing scheme of the rigid-plastic finite element method(FEM) for net-shape shell nosing components without machining after forming. The current process of the shell nosing requires cost-consuming machining to produce final products. Here, the backward tracing scheme of the rigid-plastic FEM, a novel method for preform design of metal forming processes, derives a sound preform for net-shape shell nosing product. The current process is simulated by the rigid-plastic finite element analysis to check the metal flow involved in the forming with a trial preform and its modified preform. The two preforms are found to be inadequate for net-shape shell nosing product. The first application of the back ward tracing scheme derives a preform producing a not-shape shell nosing product. The first application of the backward tracing scheme derives a preform producing a net-shape product numerically, but it is difficult to be formed economically as a preform. Thus an improved preform is designed by the badkward tracing scheme, which is suitable for net-shape manufacturing of the shell nosing components in view of economy of production and forming characteristics of the product. The preform in the current process and a modified preform are confirmed by a series of experiments and the results give the same deformation with the numerical ones. Finally the newly designed preform by the FEM was experimentally proved to be adequate in obtaining net-shape products.

A Study on Forging Process about Preform of Articulated Piston for Diesel Engine (디젤 엔진용 분절 피스톤의 예비성형체 단조 공정 연구)

  • 염성호;이병섭;노병래;서기석;홍성인
    • Transactions of Materials Processing
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    • v.13 no.7
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    • pp.635-641
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    • 2004
  • Today the specific outputs of modern supercharger DI diesel engine for passenger cars reach values exceeding 50kw/1. By development of the articulated piston, specific output of up to 70kw/1 are sought. In doing so, peak cylinder pressure increases from the current 14-16MPa to 18-20MPa. The Articulated piston was composed Al cast skirt part and steel forged crown part. We have the target fer the design of forging process and die of the steel forged crown part. The design parameters of the forging process of the piston were obtained by the forging industry experiences and our experimental data and analysis result of finite element simulation. Especially, the design parameter of preform in blocker die was decided by finite element simulation using numerical package DEFROM3D. And also we can verify the design parameter by conducting visio-plasticity test using plasticine material. When we compared the results of analysis and experiment, a metal flow and load curve showed good agreement. Through this research, we could design optimal preform shape of articulated piston for this supercharged DI diesel engine.

Forging Process Design of Articulated Piston for Diesel Engine (디젤 엔진용 Articulated Piston 단조 공정 설계)

  • 염성호;이병섭;서기석;노병래;홍성인
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.25-28
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    • 2003
  • The articulated piston that was used to more powerful diesel engine was composed by Al casted skirt part and steel forged crown part. this paper has the target to design the forging process of crown part. The parameters of piston design and forging process design were gotten based on work experience, experimental data, approximately calculated data and finite element analysis. Preform design parameter decided using the Taguchi method. Through this research, could design optimal shape of preform and produce prototype of the articulated piston

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Investigation of the Molding Conditions to Minimize Residual Stress and Shrinkage in Injection Molded Preform of PET Bottle (PET 병용 프리폼 사출성형에서 잔류응력과 수축 최소화를 위한 성형조건의 연구)

  • Cho, Sung-Hwan;Hong, Jin-Su;Lyu, Min-Young
    • Polymer(Korea)
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    • v.35 no.5
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    • pp.467-471
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    • 2011
  • PET bottle is manufactured by blow molding the preform, which is molded by injection molding. The neck part of the preform of PET bottle for juice or grain-based beverage is crystallized before blowing to improve heat resistance at the entrance of the bottle. However, residual stress, developed during injection molding of preform, prevents the crystallization. In order to release the residual stress in the preform, the preform is annealed after the injection molding. If the residual stress is reduced by optimizing the injection molding conditions of preform the annealing time would be shortened. In this study, the optimum conditions for minimizing the residual stress and increasing dimensional accuracy of the injection molded preform are suggested through CAE analysis. In order to optimize the molding conditions, minimizing residual stress and shrinkage, computer simulations have been carried out with help of design of experiment scheduling. Injection temperature, initial packing pressure and filling time were selected for control parameters. Residual stress was affected by injection temperature and filling time. Shrinkage was affected by injection temperature. It was found that maximum residual stress, distribution of residual stress and shrinkage were decreased by 22%, 40% and 25%, respectively at an optimum molding condition compared with the results of previous molding condition.

The Effect of Preform Shape for Hot-forging Process of Aluminum-alloy (예비성형체형상이 알루미늄합금의 열간단조공정에 미치는 영향)

  • Kwon, Y.M.;Lee, Y.S.;Song, J.I.;Lee, J.H.
    • Proceedings of the KSME Conference
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    • 2001.06c
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    • pp.106-110
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    • 2001
  • A effective and accurate method of hot-forging process is essential to the design of optimized dies as well as workpiece of intial shape. the former is achieved by a proper forging sequence with invokes serious problem like excessive load and die wear, die failure, underfilling and lap defects. the latter is achieved by a proper preform design of case I, case II, case III. metal forming processes of aluminum-alloy forged at an effective strain and temperature are analyzed by the finite element method. the non-isothermal analysis have been compared with optimized in terms of preform shape.

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Optimal Design of Preform in Hot forging (열간 단조에서의 최적 예비형상 설계)

  • Lee, S.R.;Lee, Y.G.;Park, C.H.;Yang, D.Y.
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.780-785
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    • 2000
  • The equi-potential lines designed in the electric field are introduced to find the preform shape in axisymmetric hot forging. The equi-potential lines generated between two conductors of different voltages show similar trends of the minimum work paths between the undeformed shape and the deformed shape. Base on this similarity, the equi-potential lines obtained by arrangement of the initial and final shapes are utilized fur the design of preform, and then the artificial neural network is used to find the range of initial volume and potential value of the electric field.

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Methodology of Perform Design for Reducing Tool Wear in Cold Forging (냉간 단조 금형의 마멸 감소를 위한 예비성형체 설계방법)

  • 이진호;고대철;김태형;김병민;최재찬
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.10a
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    • pp.164-167
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    • 1997
  • The die wear is one of the main factors affecting die accuracy and tool lifetime. It is desired to reduce die wear by developing simulation method to predict wear based on process parameters, and then optimize the process. Therefore, this paper describes disign methodology of preform for minimizing wear of finisher die in multi-stage cold forging processes. The finite element method is combined with the routine of wear prediction and the cold forging processes. The finite element method is combined with the routine of wear prediction and the cold forging process is analyzed. In order to obtain preform to minimize die wear, the FPS algorithm is applied and the optimal preform shape is found from iterative deformation analysis and wear calculation.

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