• Journal of Power System Engineering
• /
• v.7 no.2
• /
• pp.61-65
• /
• 2003

Sheet metal forming process is a non-linearity problem which Is affected by various process variables, such as geometric shape of punch and die, frictional characteristic, etc.. Therefore, the knowledge of the influence of the process variables is needed in the design of sheet metal working processes. In this paper, deep drawing tests for blank holding force, punch speed and lubrication between sheet material and tool were carried out to investigate the influence upon sheet formability. Experimental results were discussed about the defects on the deformation behaviors during the forming process.

• Transactions of Materials Processing
• /
• v.10 no.3
• /
• pp.235-245
• /
• 2001

Deep drawing process, one of sheet metal forming methods, is very useful in the industrial field because of its efficiency The deep drawing is affected by many process variables, such as blank shapes, shape radii of the punch and die, formability of materials and so on. Especially, blank shape is very important formability factor. In this study, in order to investigate the effects of blank shape, we suggested three kinds of blank shapes and examined friction test about three conditions. We measured punch load distribution according to punch stroke under the conditions of each punch and die shape radii and observed punch load of elliptical cup forming.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.3 no.1
• /
• pp.52-58
• /
• 2004

The material used is a commercial magnesium based alloy AZ31(Mg-3Al-1Zn)sheet with a thickness of 1.0mm. Uniaxial tension tests at warm temperature were carried out to investigate the material characteristics of K, m, and n. A warm drawing process with a local heating and cooling technique was developed to improve formability in this study with results of uniaxial tension tests because it is very difficult for Mg alloy to deform at room temperature by the conventional method. The die and blank holder were heated up, while the punch was water-cooled during deformation. FE simulations considering heat transfer were executed with Mg alloy to investigate the Improvement of deep drawability. For the assessment of improvement those were compare with the results of no considering heat transfer and room temperature.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1593-1596
• /
• 2003

Sheet metal forming process is a non-linearity problem which is affected by various process variables, such as geometric shape of punch and die, frictional characteristic, etc.. Therefore, the knowledge of the influence of the process variables is needed in the design of sheet metal working processes. In this paper, deep drawing tests for blank holding force, punch speed and lubrication between sheet material and tool were carried out to investigate the influence upon sheet formability. Experimental results were discussed about the defects on the deformation behaviors during the forming process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.03b
• /
• pp.88-94
• /
• 1999

This study is to investigate the effects of warm deep drawing with steel sheets of SCP3C and SCP1 for improving deep drawability. Experiments were carried out in various working conditions such as forming temperature and lubricantion. The effect of lubricantion and temperature on drawabillity of steel sheets as well as thickness distribution of drawn oil pan were examined and discussed. One step forming at room temperature and uniform distribution of thickness was achieved at optimum formability for lubricantion. The optimum forming temperature was obtained that both the die and the blankholder were heated to 10$0^{\circ}C$ while the punch was cooled by circulating coolant of $0^{\circ}C$.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1995.03a
• /
• pp.147-154
• /
• 1995

In this paper, a computer-aided design system for axisymmetric deep drawing process will be described. An approach to the system is based on the knowledge based system. The system has been written in AutoLISP with personal computer. The system is composed of four main modules, such as input , geometrical design, test & rectification and user modification . The system which aids designer provides powerful capabilities for the design of axisymmetric deep drawing process.

• Transactions of Materials Processing
• /
• v.10 no.2
• /
• pp.115-122
• /
• 2001

It is well known, for many years, that deep drawability can be improved by applying variable blank holding force. To apply variable blank holding force during cup drawing, we set up cushion pressure control system on the hydraulic press, and the pressure control system is often called NC(Numerically Controlled) cushion system. A cushion pressure control experiment was carried out using the NC cushion and it was shown that the proposed system produced good performance. The comparison of drawability of square cups with and without NC cushion showed that the drawability could be greatly improved when S-shaped pressure curve was applied. This paper includes design details of the NC cushion system and experimental analysis of drawability with NC cushion system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.10a
• /
• pp.175-179
• /
• 2004

Since the formability of AZ31 magnesium alloy is not good in room temperature, it is known that high temperature forming is advantageous. However, many studies are necessary to find the proper forming temperature for Mg alloy. In this study, experimental and FEM analysis are performed to investigate the forming temperature for AZ31 sheet. The deep drawing process of square cup is used in forming experiment and FEA. The investigations are performed in three forming temperature, room temperature, $250^{\circ}C\;and\;400^{\circ}C$. The square cup is well formed in $250^{\circ}C$ forming temperature, on the other hand, the crack and failure is presented in corner section in room and $250^{\circ}C$ forming temperature. The main cause is investigated as the effect of hardening range by the experimental and FEM results.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.938-942
• /
• 1996

Despite the increasing demand for improved product design, a limited number of works have been reported in the field of sheet metal forming. In the present study, introducing the Taguchi method, an optimal and robust combination of parameters is found and a data base management system and nomograms are utilized for knowledge acquisition. The developed system is applied to a deep drawing process, Through the present study, it is shown that the developed system is useful for the design and the formability estimation of sheet metal forming processes.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.11
• /
• pp.17-24
• /
• 1997

Despite the increasing demands for improved product design, a limited number of works have been reported in the field of sheet metal forming. In the present study, introducing the Taguchi method, an otpimal and robust combination of parameters in found and a data base management system is utilized for knowledge acquisition. Analysis data, estimation rules of formability and graphical representation of the analysis have been employed for the dewigner's understanding and evaluation. The developed system is applied to a deep drawing process. Through the present study, it is shown that the developed systerm is useful for the design and the formability estimation of sheet metal forming processes.