Prediction of Sink Phenomenon during Forging Process and Improvement of LPI Fuel Filter Housing Forging Product

LPI 차량용 연료필터 상부 하우징 냉간 단조 성형 공정에서 sink 현상 예측 및 개선

  • Kim, Jun-Young (Department of Metal Mold Design Engineering, Kongju National University) ;
  • Park, Sang-Min (Department of Metal Mold Design Engineering, Kongju National University) ;
  • Hong, Seokmoo (Department of Metal Mold Design Engineering, Kongju National University)
  • 김준영 (국립공주대학교 금형설계공학과) ;
  • 박상민 (국립공주대학교 금형설계공학과) ;
  • 홍석무 (국립공주대학교 금형설계공학과)
  • Received : 2017.03.02
  • Accepted : 2017.06.09
  • Published : 2017.06.30


The LPI fuel filter housings used in automobiles were made from conventional die castings but have recently been developed by cold forging to improve the weight and durability. On the other hand, a sink may develop at the core of the forged product due to the resulting T-shape, which not only reduces the aesthetics, but also increases the post-processing cost of the product. Therefore, this research focused on methods to predict and mitigate sink development and progression during the T-shape forging process. Finite element analysis of the forging process was first performed to determine the optimal initial workpiece devoid of burrs and underfills. An accurate sink prediction was then obtained via metal flow analysis, which was a result of the finite element simulation. Through finite element analysis, it was confirmed that sink development is a product of the differences in nodal velocities arising from the T-shaped forging process. Consequently, a pad was inserted beneath the sink to minimize these velocity differences. The results yielded significant improvement with regard to the sink defect. This method was practically applied to an industrial site to validate the sink improvement.


Cold Forging;LPI(Liquefied Petroleum Injection);Metal flow;Rigid Plastic Finite Element Method;Sink


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