• 소성∙가공
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• 제11권8호
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• pp.668-675
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• 2002

The circles deform into various shape during deformation, the major and minor axes of which indicate the direction of the major and minor principal strains. Likewise, the measured dimensions are used to determine the major and minor principal strain magnitudes. This circular grid technique of measuring strains can be used to diagnose the causes of necking and fracture in industrial practice and to investigate whether these defects were caused by material property variation, changes in lubrication, of incorrect press settings. In non-axisymmetric deep drawing, three modes of forming regimes are found: draw, stretch, plane strain. The stretch mode for non-axisymmetric deep drawing could be defined when the major and minor strains are positive. The draw mode could be defined when the major strain is positive and minor strain is negative, and plane strain mode could be defined when the major strain is positive and minor strain is zero. Through experiments the draw mode was shown on the wall and flange are one of a drawn cup, while the plane strain and the stretch mode were on the punch head and the punch corner area respectively, We observed that the punch load of elliptical deep drawing was decreased according to increase of die corner radius and the thickness deformation of minor side was more large than major side.

• 한국정밀공학회지
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• 제15권11호
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• pp.46-57
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• 1998

Even though there are some studies on the deep drawing process and process planning, little study has been done on the methodology of process planning of secondary operations of deep drawing such as 'piercins'. In this paper, first, we systematized the methodology of the process planning of secondary operations on axisymmetric cup. Second we described the development of the expert system for their CAPP For these studies, we extracted the knowledge of their process planning from experts and analysed and systemized them. To develop the expert system, rule-based reasoning paradigm is used. The shape information of manufacturing features of secondary operations are manually input to the system through SUI. The process planning results are automatically connected to AutoCAD. We believe that the systematized process knowledge and the development of the expert system for its CAPP could give lots of aids to the associated field.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.334-337
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• 2005

The objective of this research works is to propose a rapid development methodology of small size deep drawing tools for electronic parts utilizing the technology combination of CAE and RP/RT. The technology is applied to the development of deep drawing tools with a drain shape. The final surface of tools is obtained from the evaluation of the formability using the CAE. In order to manufacture the physical prototype of tools fer try-out terming, several fabrication experiments are carried out for three types of rapid tool manufacturing technology. Through the fabrication experiments, the acceptable rapid manufacturing technologies of deep drawing tools with a small size have been proposed.

• 소성∙가공
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• 제3권4호
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• pp.468-481
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• 1994

Mathematical description of arbitrarily-shaped tool surface are introduced by parametric patch approaches along with the related contact search algorithm. In order to maintain the advantages of membrane elements and to incoporate the bending effect, a BEAM(Bending Energy Augmented Membrane) element is proposed. Computation are carried out for some complex axisymmetric multi-stage deep drawing to verify the validity and the effectiveness of the proposed method.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 제2회 박판성형심포지엄 논문집 박판성형기술의 현재와 미래
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• pp.65-73
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• 1998

The design analysis of axisymmetric, multi-stage deep drawing dies was performed using the rigid-viscoplastic finite element formulation. In the formulation, the axisymmetric CFS algorithm was employed. Hill's non-quadratic normal anisotropic yield criterion and isotropic hardening rule were considered. For trial initial displacements and tool contact points, the geometric force equilibrium method was adopted. In order to see the validity of the formulation, the multi-stage deep drawing processes of shell-cylinder front part of hydraulic booster were simulated. The simulation showed good agreements with measurements and PAM-STAMP.

• 소성∙가공
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• 제24권2호
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• pp.115-120
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• 2015

Deep drawing of cylindrical cups is one of the most fundamental and important processes in sheet metal forming. Circular cups are widely used in industrial fields such as automobile and electronic appliances. Some of these cups are formed by a one-stage process, others such as battery cases and beverage cans are made by a multi-stage process. In the current study the multi-stage deep drawing of aluminum sheet metal is examined. The process consists of two deep drawing operations followed by two ironing operations. The press die, which can be used for the four-stage forming process, was manufactured allowing punch and die components to be easily changed for various experiments. The rolling direction of both the sheet and the drawn cups was always positioned toward the horizontal x-direction on the die face to minimize experimental errors during the progressive forming. The dimensional accuracy of the cylindrical cups formed at each stage and the earing defect due to the anisotropy of sheet were investigated. The influence of anisotropy on the thickness distribution was also examined. Both the thickness and the outer diameter of the cups were measured and compared for each set of experimental conditions. It was found that the dimensional accuracy of cups rapidly improves by employing the ironing process and also by increasing the amount of ironing.

• 소성∙가공
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• 제14권5호
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• pp.439-443
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• 2005

Deep drawing and cold forging processes are combined to achieve near net shape forming of automotive part which has not only drum shape but also thickness variation. It is important to find out proper intermediate shape where two totally different forming methods should be joined seamlessly. In the course of development of the combined process, finite element analysis can be utilized effectively to decide optimal position for transferring from the sheet metal work to the bulk forming. Because machining process is eliminated, significant improvement in integrity, reliability, and durability of the part is expected. The developed process combination could be applied in real manufacturing process successfully.

• 소성∙가공
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• 제9권5호
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• pp.469-477
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• 2000

Most of researches have been performed on the formability of axisymmetric shape, but it is insufficient that the study on Process variables of elliptical deep drawing Product. There are many Process variables exerted influence on the formability of products. Particularly, blank shape is more important than the others in elliptical deep drawing process. In this study, blanks of three types were proposed and compared using thickness distribution and movement of sheet during the process. The aim of a paper is to obtain optimal blank shape through experiment and finite element analysis(FEA).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.766-770
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• 1996

In this study, a CAD/CAM system for axisymmetric deep drawing processes has been developed. An approach to the system is based on the knowledge based system. Under the environment of CAD/CAM software of Personal Designer, the system has been written in UPL. The geometries of intermediate and final object in deep drawing process, including processes parameters are input for the CAD/CAM system. The input data can be obtained from the results of Pro-Deep. The parts drawing of die sets for each process is generatedin tool design module of the CAD/CAM system. Also, the die assemblydrawings can be obtained. NC commands for machining of the part can be generated in the developed CAD/CAM system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.753-756
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• 2000

The accumulated know-how and trial-and-error procedures are known as the best ways to determine blank shape and dimensions. One of the most important steps to determine the blank shape and dimensions in deep drawing process is to calculate the surface area of the product. In general, the surface area of products is calculated by mathematical or 3-D modeling methods. A blank design system is constructed for elliptical deep drawing products to recognize the geometry of the product in the long side and short side by drafting in another two layers on AutoCAD software. This system consists of input geometry recognition module, 3-D modeling module and blank design module, respectively. Blank dimension of three types is determined by the same area, which was acquired in 3-D modeling module. The suitability of this system is verified by applying to a real deep drawing product.