• 제목/요약/키워드: conventional forming

검색결과 560건 처리시간 0.025초

A Study on the Forming Load for roller feed rate and Thickness Reduction in the spinning Process of launch vehicle fuel tank dome (돔 형상의 스피닝 가공 공정에서 롤의 이송 속도와 소재의 두께감소에 대한 성형력 연구)

  • Yeom Sung-Ho;Nam Kyoung-O;Hong Sung-In
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 한국추진공학회 2006년도 제26회 춘계학술대회논문집
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    • pp.387-390
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    • 2006
  • Conventional spinning, shear forming and flow forming techniques are being utilized increasingly due to the great flexibility provided for producing complicated parts, enabling customers to optimize designs and reduce weight and cost, all of which are vital, especially in automotive industries, space shuttle, a munitions industry. The deformation mechanism of conventional spinning and shear forming is studied in this paper through analysis. The forming loads of a spin formed dome in an Al launch vehicle fuel tank was studied analysis and a simple FE model to predict the forming loads of the dome was proposed. The analysis is carried out to study the effects of feed rates and thickness reduction on material flow.

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Study on Application of Flexible Forming Technology for Curved Plate Forming using Thick Plate (후판의 곡면 가공을 위한 가변성형기술 적용 연구)

  • Heo, S.C.;Seo, Y.H.;Park, J.W.;Lee, H.M.;Ku, T.W.;Kang, B.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2008년도 추계학술대회 논문집
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    • pp.122-125
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    • 2008
  • Generally, in shipbuilding, large curved block components which have large curvature radius along various directions are used for huge ships such as LPG-vessel and oil tanker ships. Lots of the blocks are manufactured by line heating method which uses a heat source to bend the thick plate materials. The conventional forming process is entirely dependent on the experience of experts because it is done by manual method thus the curvatures and qualities are not uniform even for same part. However, it is hard to adopt the press forming process using die tool sets fur the manufacturing because of the characteristics of the industry that based on the small quantity and variety in the products. In this study, flexible forming technology using numbers of punches is investigated based on the simulation to substitute for the conventional forming method. Thick plate material model was applied to the proposed process to verify the feasibility for hull structure block forming process. The press forming processes were simulated by adopting the explicit-to-implicit sequential solution. Moreover, experiment of the flexible forming process was also conducted and its results were compared with that of simulation.

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Development and Analysis of Dry Forming System for Innovation of Papermaking Technology

  • Kim, Jong-Min;Lee, Hak-Lae;Youn, Hye-Jung;Hwang, Min-Gu
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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    • pp.181-190
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    • 2006
  • This study was conducted to develop dry forming technology and evaluate the properties of dry formed paper made from Hw-BKP. A dry forming mold (DFM) was developed to observe the phenomena of dry forming and evaluate the properties of formed papers. To upgrade the DFM a dry forming system (DFS) was developed. This DFS was designed to improve the formation of dry formed papers and enhance the productivity of dry forming. Dry forming gave papers with greater bulk and opacity than wet forming. Tensile strength of dry formed paper was greater than that of conventional wet formed handsheet when they were made from the same dry disintegrated fibers. But tensile strength of conventional wet formed handsheet made from beaten fiber was much greater than that of dry formed paper made from dry disintegrated fibers. When solvent dried beaten fibers were used in dry forming, the tensile strength of dry formed papers reached 73.5% of the wet formed handsheets made from beaten fiber. It showed that dry forming has a significant potential in improving strength properties when proper preparation of fibers and appropriate humidification, pressing, and drying processes are employed.

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Design of Cross Wedge Rolling Die for a Non-heat-treated Cold Steel using CAD and CAE (CAD/CAE를 이용한 냉간 비조질강용 회전전조 금형설계)

  • Lee H. W.;Yoon D. J.;Lee G. A.;Choi S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2004년도 춘계학술대회 논문집
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    • pp.400-403
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    • 2004
  • A non-heat기leafed steel does not need quenching and tempering processes that are called a heat treatment differently from conventional steel. Since the tensile strength of this steel is higher than 900MPa, a conventional forming process should be changed to incremental forming process such as a cross wedge rolling that requires lower load capacity than conventional ones. In this paper, the cold cross wedge rolling (CWR) die has been designed using CAD/CAE In order to produce near-net-shaped component of ball stud of non-heat-treated cold steel. Finite element analyses were applied in order to investigate process parameters of CWR. Results provide that the stretching angle and the forming angie at knifing zone in CWR process is important parameter to be the stable process under the low friction coefficient condition.

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Evaluation of Formability and Mechanical Characteristic for Hot Forming Quenching in Sheet Forming of Al6061 Alloy (Al6061 판재성형에서 핫 포밍 ��칭의 성형성 및 기계적 특성 평가)

  • Ko, Dae Hoon;Kim, Jae Hong;Lee, Chan Joo;Ko, Dae Cheol;Kim, Byung Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • 제37권4호
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    • pp.483-490
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    • 2013
  • In aluminum sheet metal forming, the conventional forming methods of T4 or T6 heat-treated sheets result in low formability and dimensional accuracy. This study suggests a new forming method for aluminum sheets called as hot forming quenching (HFQ) that solves the problems faced in the conventional method. HFQ combines the heat treatment and forming processes through the forming die during the quenching of a solid solution. To evaluate the application of HFQ to the sheet forming of aluminum, an Erichsen and V-bending test are performed in this study to measure the dimensional accuracy and formability, which are then compared with those of the conventional forming method. Furthermore, the strength and hardness of the products formed by HFQ are measured to confirm the degradation in mechanical properties compared with the conventional forming method, which shows the validity of the application of HFQ to aluminum sheet metal forming.

Multi-Stage Forming Analysis of a Milli-Component for Improvement of Forming Accuracy (밀리부품의 정밀도 향상을 위한 다단계 성형 및 금형 해석)

  • Yoon, J.H.;Huh, H.;Kim, S.S.;Na, G.H.;Park, H.J.;Choi, T.H.
    • Transactions of Materials Processing
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    • 제13권5호
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    • pp.429-434
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    • 2004
  • Manufacturing process for milli components has recently gained researcher's focus with the increasing tendency toward highly integrated and micro-scaled parts for electronic devices. The milli-components need more precise manufacturing process than the conventional manufacturing process since the parts require higher dimensional accuracy than the conventional ones. In order to enhance the forming accuracy and productivity, various forming procedures proposed and studied by many researchers. In this paper, forming analysis of milli-components has been studied with a new micro-former. In modeling of progressive dies, multi-stage forming sequence has been analyzed with finite element analysis by LS-DYNA3D. The analysis proposes the sequential die and part shapes with the corresponding punch force and dimensional accuracy. The analysis also considers the effect of elastic dies on the dimensional accuracy of the formed parts. The analysis result demonstrates that the elastic analysis in the milli-forming process is indispensable for accurate forming analysis. The analysis procedure in the paper will provide good information in design of a new micro-former and milli-component

Process Design of Automobile Steering Yoke with burring (버링 가공을 이용한 자동차 요크 제품의 가공 공정 설계)

  • 김병민
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2000년도 춘계학술대회논문집
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    • pp.151-154
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    • 2000
  • The yoke is used for joining the mechanical element of a spider and shaft in the steering system of automobiles. Conventional yoke forming processes are too complicated such as 4 stages bending and forming. The weight of yoke is also heavy than other components. New process is necessary to reduce the product weight to improve the strength and to reduce the costs. Process designed to reduce number of forming stages and to reduce its weight. To check the strength the stress analyses are performed between conventional yoke and developed one.

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Numerical Study on Forming Characteristics of Hot Multi-Point Forming Die (수치해석을 이용한 열간 가변금형 성형특성 평가)

  • Lee, I.K.;Lee, S.Y.;Jeong, M.S.;Kim, B.M.;Lee, S.K.
    • Transactions of Materials Processing
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    • 제27권4호
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    • pp.236-243
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    • 2018
  • A multi-point forming die (MPFD), which has been used for producing curved plates, is capable of forming various curved plates with just one MPFD. However, in real industries, an MPFD is difficult to be adopted since the structural properties, punch strength, elastic recovery correction and dimensional accuracy become problems. In order to overcome these problems, the hot multi-point forming die (HMPFD) was proposed in this study. This HMPFD commonly provide more less spring-back and forming load than conventional MPFD. Nevertheless, this process is very difficult to form the curved plate, because the final curved shape of the plate depends on many process variables such as the punch/nozzle arrangement (height and distance), the radius of punch, contact conditions between plate and punch. In this study, the forming characteristics of HMPFD and conventional MPFD are compared with each other through the finite element analysis.

Structural analysis of the Micro-Former based on results from the forming analysis for milli components (밀리부품 성형해석을 통한 Micro-Former의 거동해석)

  • Yoon J.H.;Huh H.;Kim S.S.;Choi T.H.;Na G.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2004년도 춘계학술대회 논문집
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    • pp.118-121
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    • 2004
  • Manufacturing process for milli components has recently gained researcher's focus with the increasing tendency toward highly integrated and micro-scaled parts for electronic devices. The milli-components cannot be formed by the conventional manufacturing process since the parts require higher dimensional accuracy than the conventional ones. In order to enhance the forming accuracy and productivity, various forming procedures proposed and studied by many researchers. In this paper, forming analysis of milli-components has been studied with a new micro-former. In modeling of progressive dies, multi-stage forming sequence has been analyzed with finite element analysis by LS-DYNA3D. The analysis proposes the sequential die and part shapes with the corresponding punch force and dimensional accuracy. The analysis also considers the effect of elastic dies on the dimensional accuracy of the formed parts. The analysis result demonstrates that the elastic analysis in the milli-forming process is indispensable fur accurate forming analysis. The analysis procedure in the paper will provide good information in design of a new micro-former and milli-component.

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Net Shape Forming Process for Ball Stud Using High Strength Micro-Alloyed Cold Forging Steel (냉간 비조질강을 이용한 볼 스터드의 정형가공 공정연구)

  • Yoon, D.J.;Choi, H.J.;Lee, H.W.;Lee, G.A.;Jang, B.L.;Seo, S.L.;Choi, S.
    • Transactions of Materials Processing
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    • 제15권8호
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    • pp.562-567
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    • 2006
  • Micro-alloyed steel or heat-treatment-free used in clean technology have been replacing for conventional quenched-and-tempered structural steels since the micro-alloyed forging steel was developed in early 1970s in Germany for saving money of heat treatment, simplified process, short delivery and good productivity. In this paper, ball stud assembled in steering system for automobile was selected to compare conventional process making heat treatment with new process using high strength micro-alloyed steel without heat treatment. The conventional process for ball stud was composed of a total of 6 steps including upsetting, forward extrusion, machining, burnishing and tread rolling with heat treatment and shot blasting. As opposed to conventional process, newly proposed process for ball stud using the clean technology without heat treatment is simplified such as forward extrusion, heading, upsetting, forming having a flange shape and tread rolling. Also net shape forming process to achieve specified process not to include machined step fur manufacturing the ball stud was applied to newly simplified process since micro-alloyed steel is difficult to be formed.