• Journal of the Korean Society of Industry Convergence
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• v.21 no.4
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• pp.175-181
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• 2018

Stamping process and rubber pad forming process were performed to manufacture the bipolar plate for fuel cells. For that, a vacuum die casting process and a semi-solid forming process wherein liquid-state materials were used were adopted. After preparing the blank with the stainless steel thin plate having a thickness of 0.1 mm, the bipolar plate channel was formed with the stamping process and rubber pad forming process. The depth of the bipolar plate channel prepared by the stamping method was 0.45 mm and the depth of the bipolar plate channel prepared by the rubber pad forming process was 0.41 mm. Meanwhile, with the vacuum die casting and semi solid forming, the bipolar plate having a channel depth of 0.3 mm, same as the size of the die, could be formed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.405-408
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• 2004

The forming load and the stress applied to dies during cold forming of automotive part using microalloyed forging steel are examined with finite element analysis. The forming load and the stress applied to dies at each process step are investigated for two types of forming process. The changes in forming process significantly affect the variation of firming load and the stress at each process step, thus it is considered that the die lift will be remarkably changed with the type of forming process, therefore optimal process design is necessary to obtain an increased the die life and to make the die life uniform at each process step.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.44-47
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• 2002

In order to make a doubly curved sheet metal effectively, a sheet metal forming process has been developed by adopting the flexibility of the incremental forming process and the principle of bending deformation which causes slight deformation to thickness. The developed process is an unconstrained forcing process with no holder. For this study, the experimental equipment is set up with the roll set which consists of two pairs of support rolls and one center roll. In the experiments using aluminum sheets and FEM simulation, it is found that the curvature of the formed sheet metal is determined by controlling the distance between supporting rolls in pairs and the forming depth of the center roll. The FEM simulation of the forming process using the roll set along the one path shows the distributions of the curvatures in two directions along the path, and gives information about the characteristics of the proposed forming process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.3
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• pp.38-45
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• 2009

Recently, LCD Backlight Unit is being replaced from cold cathode fluorescent lamp(CCFL) to external electrode fluorescent lamp(EEFL) because the EEFL has high energy efficiency and long life. Also, it can reduce energy consumption and weight. So far, external electrode ring for EEFL is produced by sheet metal press forming process. Therefore it had low precision and much material loss. To solve these problems, Multi-Forming process that has five step forming process was invented. However, low productivity is another barrier. Product speed that is controlled by the rotational speed cannot be increased due to the unsatisfied design specification. The reason is that the gap between rolled two edge parts of the sheet plate is tightly inspected. Regarding this factor, the understanding of forming behavior to each process is inevitable. This paper describes the CAE analysis of the multi-forming process by PAM-STAMP.

• Transactions of Materials Processing
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• v.10 no.3
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• pp.246-246
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• 2001

The conventional and new forming processes of a steel shell body are analyzed by the rigid-plastic finite element method. The conventional process contains five forming stages such as bending, drawing, ironing, heading and sizing, which was designed by a forming equipment expert. The results of simulation of the conventional forming process are summarized in terms of deformation patterns and load-stroke relationships for each forming operation. Based on the simulation results of the current five-stage, the shell body forming Process including backward extrusion is designed for improving the conventional process sequence. Forming loads of the proposed process are within the limit value, which is proposed by experts and the proposed process is found to be proper for manufacturing steel shell body.

• Transactions of Materials Processing
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• v.10 no.3
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• pp.245-252
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• 2001

The conventional and new forming processes of a steel shell body are analyzed by the rigid-plastic finite element method. The conventional process contains five forming stages such as bending, drawing, ironing, heading and sizing, which was designed by a forming equipment expert. The results of simulation of the conventional forming process are summarized in terms of deformation patterns and load-stroke relationships for each forming operation. Based on the simulation results of the current five-stage, the shell body forming Process including backward extrusion is designed for improving the conventional process sequence. Forming loads of the proposed process are within the limit value, which is proposed by experts and the proposed process is found to be proper for manufacturing steel shell body.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.210-213
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• 2005

Recently a number of parts have a tendency to be a module for saving weight, cost, process and high quality in automotive industry. The forming process to combine automotive rack tube which was consisted on many parts is various. This paper presents tube forming process using elasto-forming process. We investigated the properties of rubber and tube by Finite Element Analysis. And it was compared with the experimental results for the formability of tube. we was to suggest a forming process using moving die for elasto-forming process, and through this improvement we could get the good formability.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.118-121
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• 2008

Flexible die is more efficacious than fixed die which is generally used in stretch forming process in view of production cost. Accordingly, in order to verily the validity of the flexible forming process, curved thin skin structure forming analyses using the fixed and flexible die were performed. As results, merit and demerit with regard to the fixed and flexible die were confirmed. The result of the stretch forming process analysis using the flexible die was better than that using the fixed die in view of the elastic recovery. However wrinkles were occurred on the sheet material due to die cavities between the punches in the flexible forming process, thus the solutions against these problems were presented.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.18-21
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• 1999

In this study in order to make doubly-curved sheet metal effectively a sheet metal forming process has been developed by adopting the flexibility of the incremental forming process and the principle of bending deformation which causes slight deformation to thickness The developed process is an unconstrained forming process with no holder. For this study the experimental equipment is set up with the punch-set which consists of two pairs of lower support-punches and one upper center-punch. In the experiments using aluminum sheet it is found that the curvature of the formed sheet metal is determined by controlling the distance between supporting punches in pairs and the forming depth of the center-punch. and the edge-forming method is proposed for forming the sheet metal into the balanced shape. The equation using process variables such as the distance between supporting punches in pairs and the forming depth of the center-punch is proposed for the prediction of the radii of curvatures of the formed shape and it is corrected by the experimental results and the FEM simulation results about whether springback takes place. It is found that according o the simulation there is a certain set of the distance between a pair of supporting punches and the forming depth of the center-punch which causes a little springback. It is thus shown that the radii of curvatures of the formed sheet metal can be predicated by the corrected equation unless significant springback occurs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.320-323
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• 2002

This paper discusses process design of cold forging for inner tooth part, drum clutch. In respect to high productivity, low material consumption and low piece production costs, Metal forming has more merits than machining process. Net shape forming is huh technology which satisfies merits of metal forming and achieves high accuracy. Recently, net shape forming method widely applied because of high productivity, low material consumption and low piece production costs using press. In this study, the method which accuracy of drum clutch, automatic transmission pin, can be improved is discussed. First, process variables for process design of drum clutch are selected, and then process design is accomplished using forming analysis method. from forming analysis, forming load, stress, unfiling part is obtained. and comparing these results, optimal process design can be determined.