• Journal of Korea Foundry Society
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• v.32 no.2
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• pp.65-74
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• 2012

In this paper, we present the results of our studies on optimal die design towards development of a vacuum die casting process to fabricate fuel cell bipolar plate with micro-channel array. Cavity and overflow shape is designed by computational filling analysis of MAGMA soft. Optimal die design consists of seven overflows at the end of cavity and three overflows at each side wall of cavity. The molten metal that passed the gate and reached the side wall flowed into the side overflow, no turbulent flow occurred, and the filling behavior and velocity distribution were uniform. In addition, partially solidified molten metal passing through the channel was perfectly eliminated by overflow without back-flow. When vacuum pressure, injection speed of low and high region was 300 mbar, 0.3 m/s and 2.5 m/s respectively with Silafont 36 die casting alloy, sound sample without casting defects was obtained. The experimental results are nearly consistent with simulation results.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.269-274
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• 2001

In order to reduce trial-and-errors in the die design and production, CAE systems for analysis of stamping tools have been introduced at the initial design stage recently. For optimal design, the CAE engineers may need to correct the meshes generated by automatic mesh generation programs. However, they may need help of CAD engineers as they are usually not skilled in manipulation of CAD systems. In order to get around these problems, automatic shell mesh modification method is proposed, which utilizes existing CAD/CAE package (in this study, I-DEAS) without user interaction. The developed method and optimization techniques are applied to a stamping die rounding optimization problem. The optimization results show that the manpower and the time required at virtual tryout can be reduced by using the developed systems.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.418-422
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• 2005

In this study, the die design and die series on the surface residual stress of cold drawn eutectoid steel wire has been investigated. Test pieces were fabricated using die series with different mean and final reduction ratio. Surface residual stresses in the axial direction were measured by X-ray diffraction, Broker's 2-dimensional GADDS system. Results were compared with stress profiles which were calculated by 3D and 2D finite element simulation, Hibbitt's ABAQUS 6.4 program in Finite Element Analysis. By means of FEA method, optimal die shape considering delta-parameter were induced and applied in order to determine die sequence designs. Balance of the drawing stresses was also introduced to optimize die sequence.

• Transactions of Materials Processing
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• v.15 no.2 s.83
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• pp.153-157
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• 2006

In this study, the die design and die series on the surface residual stress of cold drawn eutectoid steel wire have been investigated. Test pieces were fabricated using die series with different mean and final reduction ratios. Surface residual stresses in the axial direction were measured by X-ray diffraction, Bruker's 2-dimensional GADDS system. The results were compared with stress profiles that were calculated by 3D and 2D finite element simulations, ABAQUS 6.4 program in finite element analysis(FEA). By means of the FEA method, optimal die shape considering delta-parameter were induced and applied in order to determine die sequence designs. Balance of the drawing stresses was also introduced to optimize die sequence.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.4
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• pp.82-88
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• 2002

Copper bus-bar is made by drawing process and used in many part of industry. Ohen design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper it is analyzed to determine shrink fit value by shrink fit analysis program which is used with APDL/UIDL language in a commercial FEM package, ANSYS. The shrink fit analysis has been developed that enables optimal desist of the dies taking into account the elastic deflections. Elastic deflection is generated in shrink fitting the die inserts and that caused by the stresses generated using DEFORM software for drawing process analysis. This data can be processed as load input data fir a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• Transactions of Materials Processing
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• v.7 no.6
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• pp.586-593
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• 1998

In recent automotive industries there has been significant increase in applications of computer simulation to the manufacturing of stamping dies for inner and outer body panels which greatly affect durability and aesthetic quality of automobiles. Enhancement of die quality and reduction of total die manufacturing time and consequently manufacturing cost are the visible outcome. However to successfully apply the result of simulation by a commercial package to the die manufacturing development of an optimal die manufacturing process is required upon the completion of analysis of forte and shortcoming of available sheet metal forming softwares. Based on the results of numerical analysis of front door outer panel forming. this paper evaluates the applicability of simulation results to the real die manufacturing for automotive body panels. Also it attempts to select an optimal die manufacturing process including design machining and tryout. Lastly it discusses the expected effects by adopt-ing the selected process in a real stamping die manufacturing facility.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.361-366
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• 2004

The die casting process was used to manufacture an automotive alternator housing. Generally automobile parts are required to be light and have high strength. The control of casting defects is important but has usually been depended only on the experience of the foundry engineer. Therefore simulations have been carried out on the die casting process of alternator housing. In this paper. we investigated the characteristics of the die casted alternator housing with the HPDC(High Pressure Die Casting) process. We presented the results of filling behavior and solidification process of the cast, The analysis results obtained from the filling behavior and solidification of cast agreed with test results.

• IE interfaces
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• v.13 no.4
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• pp.717-724
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• 2000

In this paper, an integrated system of optimal design, performance evaluation, and die design and manufacturing of axial fans for cooling tower is presented. The design and performance evaluation are developed based on three dimensional flow analysis so as to ensure low noise and high efficiency. The methodologies are implemented on computer as a GUI system including 3-D surface modeling and 2-D drawing file output modules. The CAD/CAM system is engaged to design the die and generate NC tool path, but the processes are also automated and integrated into the system by means of a part program coded from the design data. It is shown that the newly developed fans have superior performance and shortened lead-time compared to the existing dead-copied fans.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.11a
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• pp.45-53
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• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.166-171
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• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.