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Forming of Dome and Inlet Parts of a High Pressure CNG Vessel by the Hot Spinning Process

열간 스피닝 공정을 통한 CNG 고압용기의 돔 및 입구 부 성형

  • Lee, Kwang O (Research Institute of Mechanical Technology, Pusan Nat'l Univ.) ;
  • Park, Gun Young (Research Institute of Mechanical Technology, Pusan Nat'l Univ.) ;
  • Kwak, Hyo Seo (Dept. of Mechanical Convergence Technology, Pusan Nat'l Univ.) ;
  • Kim, Chul (Research Institute of Mechanical Technology, Pusan Nat'l Univ.)
  • 이광오 (부산대학교 기계기술연구원) ;
  • 박건영 (부산대학교 기계기술연구원) ;
  • 곽효서 (부산대학교 기계융합기술학과) ;
  • 김철 (부산대학교 기계기술연구원)
  • Received : 2016.05.16
  • Accepted : 2016.07.04
  • Published : 2016.10.01

Abstract

The CNG pressure vessel is manufactured by a deep drawing and ironing (D.D.I) process for forming cylinder parts, followed by a spinning process for formation of the dome part. However, studies on the buckling phenomenon of the dome part and formation of the inlet part have not been performed yet, and the CNG pressure vessel is produced by the experience of the field engineers and the trial and error method. In this study, buckling phenomenon during the spinning process was predicted by comparing critical buckling loads obtained through theoretical analysis with axial loads from the FEA, and a method for preventing buckling of the dome part was proposed by employing commercial software (Forge NxT 1.0.2). Also, to form the inlet part, forming loads of the roller at contact point between the roller and the dome part were analyzed according to radii of the dome part, and the inlet part was formed by controlling the radius of the dome part.

압축천연가스(CNG) 압력용기는 D.D.I공정을 통해 실린더부를 제작한 후, 스피닝 공정을 통해 돔 부 성형이 이루어진다. 그러나 스피닝 공정의 입구 부 성형에 관한 연구는 미미하며, 현장 작업자들의 경험이나 시행착오에 의해 제작되고 있는 실정이다. 이에 본 연구에서는 이론 임계좌굴하중 및 유한요소해석에서 축 방향 하중의 비교를 통하여 좌굴발생을 예측하였고, 상용 소프트웨어를 이용하여 돔부의 좌굴 방지를 위한 방법을 제안하였다. 또한, 입구 부 성형을 위하여 돔 부와 롤러가 맞닿는 점에서의 돔부의 반경에 따른 롤러 하중을 분석하고, 이를 토대로 입구 부 성형을 수행하였다.

Acknowledgement

Supported by : 한국연구재단

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