• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.12 s.177
• /
• pp.156-162
• /
• 2005

In this paper, we study the mechanism of lead deformation by numerically simulating the stamping process by means of a commercial finite element code. It is very important to analyze effects that the lead shape makes on the lead deformation, because the lead shape is often modified in order to minimize the deformation or to increase the buckling critical load of the punch. Therefore the stamping process, first, numerically simulated by considering as a quasi-static problem. Second, the effect on the lead deformation due to the lead shape variation, a linear lead geometry and a bent lead, was numerically analyzed and discussed. Finally, the punching order was optimized fur multi-lead generating stamping process. The results show that the bent lead is little bit more shifted than the linear lead after the punching process. But the bent lead is vertically less deformed than the linear lead. The punching order to successively generate the lead is good to keep the lead space uniform. The results will be very effectively applied for the design of the blanking or punching dies in industry.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2000.10a
• /
• pp.109-113
• /
• 2000

The piercing and blanking of thin sheet metal working with a pilot punch guide is specified division in press die design and making. In order to prevent the detects, the optimum design of the production part, strip process layout, die design, die making and try out etc. are necessary the analysis of effective factors. For example, theory and practice of metal shearing process and its phenomena, die structure, machine tool working for die making, die materials and its heat treatment, metal working in industrial and its know how etc. In this study, we analyzed whole of data base, theoretical back ground of metal working process, and then performed the progressive die tryout with the screw press. This study regards to the aim of small quantity of production part's press working by piloting for accurate guide of actual sheet metal strip. Part 1 of this study reveals with production part and strip process layout for the die design.

• Proceedings of the KAIS Fall Conference
• /
• 2004.06a
• /
• pp.42-46
• /
• 2004

0.5mm thick steel is used to manufacture nail files. The first process is blanking the blank and then make about 300 holes of 0.8$\~$1.0mm in diameter. This process depends mainly on etching which takes $33\%$ of manufacturing cost and it can make manufacturing cost rise. The residual etching reagent is not environmentally friendly and the steel material is apt to rust as well. The key accomplishments of this research are to change the material from steel to stainless and develop a progressive perforating die in place of etching process.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.8
• /
• pp.93-98
• /
• 2022

Adiabatic blanking is a method to improve productivity through an autocatalytic cycle that occurs repeatedly through plastic deformation and thermal softening caused by impact energy. In this study, an axisymmetric analysis model comprising a punch, die, holder, and specimen was developed to confirm the temperature and deformation characteristics caused by an impact load. Through this, the impact energy, diameter of the punch, gap between the punch and die, and the effect of the fillet were analyzed. Because this process occurs in a very short time, adiabatic analysis can be performed using the explicit time-integration method. The analysis, confirmed that it is necessary to design a structure capable of increasing the local temperature and plastic deformation by controlling the impact energy, working area, gap, and the fillet.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.143-148
• /
• 2004

The blister packaging is applied to many fields in recent years for its merit that it enable consumer to see the products. The most of battery packaging are blister type. However, the lithium battery is dealt with very carefully in packaging because of its explosion. The existing packaging machines lot lithium battery are mostly adapted alkaline packaging machine and their capacity is very inferior to other process, either. In this paper, the virtual prototype of the automatic blister packaging system for lithium battery which has new mechanism is developed and its performance is evaluated.

• Design & Manufacturing
• /
• v.6 no.1
• /
• pp.95-100
• /
• 2012

In this study, a novel Cu composite sheet with embedded high electric conduction path was developed as another alternative for the interconnect materials possessing high electrical conductivity as well as high strength. The Cu composite sheet was fabricated by forming Ag conduction paths not within the interior but on the surface of a high strength Cu substrate by damascene electroplating process. As a result, the electrical conductivity increased by 40% thanks to mesh type Ag conduction paths, while the ultimate tensile strength decreased by 20%. The interfacial fracture resistance of Cu composite sheet prepared by damascene electroplating increased by above 50 times compared to Cu composite sheet by conventional electroplating. For feasibility test for practical application, a leadframe for LED module was manufactured by a progressive blanking and piercing processes, and the blanked surface profile was evaluated as a function of the volume fraction of Ag conduction paths. As Ag conduction path became finer, pressing formability improved.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.10a
• /
• pp.149-154
• /
• 2003

The blister packaging is applied to many fields in recent years for its merit that it enable consumer to see the products. The most of battery packaging are blister type. However, the lithium battery is dealt with very carefully in packaging because of its explosion. The existing packaging machines for lithium battery are mostly adapted alkaline packaging machine and their capacity is very inferior to other process, either. In this paper, the virtual prototype of the automatic blister packaging system for lithium battery which has new mechanism and 240A/min capacity is developed and its performance is evaluated.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.4
• /
• pp.309-314
• /
• 2004

0.5mm thick steel is used to manufacture nail files. The first process is blanking and the second process is making about 300 holes of 0.8-l.0mm in diameter. This process depends mainly on etching which takes 33% of manufacturing cost and it can make manufacturing cost rise. The residual etching reagent is not environmentally friendly and the steel material is apt to rust as well. To solve these problems, researches on the following subjects are performed: proper material to prevent from rusting and strip layout strategies in stamping to replace etching process with press process which makes use of die. And new quill type punch is developed to replace the regular standard punch, one of the die parts, which frequently get broken while working. And these researches and developments lead to develop a progressive perforating die.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.12
• /
• pp.230-238
• /
• 1999

This paper describes a research work of developing computer-aided design of lead frame, semiconductor, with blanking operation which is very precise for progressive working. Approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. This system has been written in AutoLISP on the AutoCAD using a personal computer and in I-DEAS Drafting Programming Language on the I-DEAS Master Series Drafting with Workstation, HP9000/715(64) and tool kit on the ESPRIT. Transference of data among AutoCAD, I-DEAS Master Series Drafting, and ESPRIT is accomplished by DXF(drawing exchange format) and IGES(initial graphics exchange specification) methods. This system is composed of six modules, which are input and shape treatment, production feasibility check, strip-layout, die-layout, modelling, and post-processor modules. The system can design process planning and Die design considering several factors and generate NC data automatically according to drawings of die-layout module. As forming process of high precision product and die design system using 2-D geometry recognition are integrated with technology of process planning, die design, and CAE analysis, standardization of die part in die design and process planning of high pression product for semiconductor lead frame is possible to set. Results carried out in each module will provide efficiencies to the designer and the manufacturer of lead frame, semiconductor.

• Transactions of Materials Processing
• /
• v.19 no.6
• /
• pp.337-343
• /
• 2010

Current need of weight reduction in automotive part increases the application for high strength steel (HSS). The various types of high strength steels have been used to produce chassis part, control arms and trailing arms for weight reduction and increasing of fatigue durability such as dual phase steel (DP) and ferrite bainite steel (FB). But, DP and FB steels have proven to show inferiority in durability as well as press formability. Edge cracking occurred often in flange forming and hole expansion processes is the major failure encountered. This paper discussed the behavior of edge stretchability of high strength steel of DP and FB steels. Experimental works have been conducted to study the effect of punch clearance and burr direction on hole expansion ratio (HER). Also finite element simulation (FEM) has been preformed to clarify the mechanism of flange crack and support the experimental results on HER of DP and FB steels. It was simulated the whole process of blanking process following by hole expansion process and ductile fracture criterion named the modified Cockcroft-Latham model which was used to capture the fracture initiation. From the hole expansion tests and FEM simulation studies it was concluded that ferrite bainite steel showed better stretch-flangeability than dual phase steel. It was attributed to the lower work hardening rate of ferrite bainite steel than dual phase steel at the sheared edge.