• Title/Summary/Keyword: Electric Upsetting

Search Result 6, Processing Time 0.025 seconds

Rigid-thermoviscoplastic finite element analysis of an electric upsetting process (전기 업셋팅 공정의 강열점소성 유한요소해석)

  • Lee, M.C.;Choi, I.S.;Kim, H.T.;Joun, M.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2007.10a
    • /
    • pp.177-182
    • /
    • 2007
  • We simulated an electric upsetting process by the rigid-thermoviscoplastic finite element method. Several engineering assumptions were made to calculate the heat generation due to the electric resistance. The skin effect of the bar was taken into account for the heat generation. The approach was applied to simulate an artificial electric upsetting process for the exhaust valve of the ship engine.

  • PDF

Rigid-Thermoviscoplastic Finite Element Analysis of an Electric Upsetting Process (전기 업셋팅 공정의 강열점소성 유한요소해석)

  • Choi, In-Su;Kim, Min-Cheol;Kim, Hong-Tae;Joun, Man-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.10 no.6
    • /
    • pp.152-158
    • /
    • 2011
  • An electric upsetting process by the rigid-thermoviscoplastic finite element method was simulated in this study. Several engineering assumptions were made to calculate the heat generation due to the electric resistance. The skin effect of the bar was taken into account for the heat generation. The approach was applied to simulate an artifical electric upsetting process for the exhaust valve of the ship engine.

A Study on the Temperature Distribution of Materials Due to Electric Upsetting Forming (전기 엎셋팅 가공시의 온도분포에 관한 연구)

  • 왕지석;박태인
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.18 no.3
    • /
    • pp.1-9
    • /
    • 1994
  • The transient temperature distribution of materials during upsetting forming is very important for quality of upsetted workpiece and understanding the thermal characteristics of upsetting is essential for optimum control of the forming. In this paper it is shown that the governing equation of heat transfer for axi-symetric body can be derived from minimizing a functional, and from this theory, formulation of analysis by the finite element method is presented. It is also shown that the thermal contact resistance between two bodies can be represented by equivalent coefficient of heat conductivity. Some examples of calsulated transient temperature distributions by the computer program diveloped from the theory presented in this paper are given in graphic forms. It is proven that the results calculations are very plausible.

  • PDF

Weld Defect Formation Phenomena during High Frequency Electric Resistance Welding

  • Choi, Jae-Ho;Chang, Young-Seup;Kim, Yong-Seog
    • Journal of Welding and Joining
    • /
    • v.19 no.3
    • /
    • pp.267-273
    • /
    • 2001
  • In this study, welding phenomena involved in formation of penetrators during high frequency electric resistance welding were investigated. High speed cinematography of the process revealer that a molten bridge between neighboring skelp edges forms at apex point and travels along narrow gap toward to welding point at a speed ranging from 100 to 400 m/min. The bridge while moving along the narrow gap swept away oxide containing molten metal from the gap, providing oxide-free surface for a forge-welding at upsetting stand frequency of the budge formation, travel distance and speed of the bridge were affected by the heat input rate into strip. The travel distance and its standard deviation were found to have a strong relationship with the weld defect density. Based on the observation, a new mechanism of the penetrator formation during HF ERW process is proposed.

  • PDF

A Research on Lengthening the Life of Warm Forging Die (온간단조금형의 수명연장에 관한 연구)

  • Kim, Sei-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.1
    • /
    • pp.49-54
    • /
    • 2010
  • Rotor pole for AC(alternating current) generator is manufactured through transfer warm forging die. As soon as the material is heated at the warm manufacturing process, it is transferred to the first stage for upsetting work and then to the second stage for lateral extrusion work. The processes at the lateral extrusion work such as die block, die bushing, center punch, and side punch make severe condition and abrasion which leads to shorten the die life. This causes production decrease, long maintenance time, and low level of precision. Research on the die material selection, heat process cycle improvement, electric discharge machining trouble solution, and re-construction of main parts is expected to find a method to lengthen the die life up to 40 - 50%.

An investigation of non-uniform metal flow during rectangular battery case using impact extrusion process (충격압출 공정을 이용한 직사각형 배터리 케이스 성형 시 불균일 금속 유동 발생 원인 고찰)

  • Lim, Jae-Hyuk;Kim, Yong-bae;Lee, Jong-sup
    • Design & Manufacturing
    • /
    • v.10 no.2
    • /
    • pp.24-28
    • /
    • 2016
  • In this study, relevant to impact extrusion process of the rectangular batter case for electric vehicles, numerical and experimental analyses were conducted to reduce the earring defects induced in the unevenness of metal flow. Since the earring is caused by the non-uniform metal flow induced in the friction and aspect ratio in the bottom section. As a way to reduce the earring, variable land die concept was applied. In order to analyze numerically the complex metal flow by using commercial finite element package, DEFORM 3D, impact extrusion process was simplified in upsetting mode at bottom section and extrusion mode at land section. The impact extrusion experiments were conducted to verify the assessment of process parameter for impact extrusion. As results, variable land die which has longer longitudinal section makes reduce earring defects. In addition, it was confirmed that the effect that slug shape like dog-bone also can reduce the earring. This study is expected to be able to present the useful design guidelines for manufacturing the battery case.