• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.283-287
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• 2003

In recent years, design of an optimal blank shape is very important for sheet metal forming process in the automobile industry because the raw material cost rate is significant part in the automobile industry. With the design of an optimal blank shape, the engineer can protect a blank from an excessive holding force to improve the quality and reduce the ratio of material scrap. Therefore design of an optimal blank shape is inevitable in sheet metal forming process. However, if it causes a complicated shape of blank, it may be difficult to do the blank layout optimally. In this study, we developed software of optimal blank layout connected with the software of optimal blank shape design which was created in the past by the present authors. And by using these softwares, we would like to present the method in order to get optimal utilization ratio easily and precisely within short time for the sequence of works from design to blank layout.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.9
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• pp.46-53
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• 1996

This paper describes some research works of computer-aided design of blanking and piercing for stator and rotor parts and irregularly shaped sheet metal by press. An approach to the system is based on knowledge based rules. The process planning system by considering a blank layout for nesting of irregularly shaped sheet metal and an improved strip layout for stator and rotor parts and irregularly shaped sheet metal is implemented. Using this system, design parameters(utilization ratio, slitting width, pitch, working order, die blank shapes) are determined and output is generated in graphic forms. Knowledges for blank layout and strip layout are extracted from the plasticity theories, handbooks, relevant references and empirical know-hows of experts in blanking companies. The implemented system provides powerful capabilities for process planning of stator and rotor parts and irregularly shaped sheet metal.

• Design & Manufacturing
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• v.2 no.3
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• pp.51-57
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• 2008

It is important factor to design the strip layout drawing according to product properties in press die design. Press dies are important processes in production such as a car component, house electronics, computer parts etc. In this paper, the strip layout of parts was designed for transfer dies. Results of this study can be modify the punch, trim position and notching shapes of strip layout. Utilization ratio was 70.3% by conducting piercing and notching for scrap design and materials were arranged with wide width of blank layout.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.174-182
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• 1998

This paper describes a research work of developing a computer-aided design and machining of irregular shaped-sheet metal product for blanking or piercing operation. An approach to the CAD/CAM system is based on the knowledge-based rules. Knowledge for the CAD/CAM system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD and in customer tool kit on the SmartCAM with a personal computer and is composed of nine modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, strip-layout, die-layout, data conversion, modelling, and post-processor module. Based on knowledge-based rules, the system is designed by considering several factors, such as material and thickness of product, complexities of blank geometry and punch profile, diameter and material of a wire, and availability of press. This system is capable of generating NC data automatically according to drawings of die-layout module. Results which are carried out in each module will provide efficiencies to the designer and the manufacturer of blanking or piercing die in this field.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.22-32
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• 1998

This paper describes a research work of developing a computer-aided design of irregularly shaped-sheet metal product with bending and piercing operation for progressive working. An approach to the CAD system is based on the knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of five main modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, and strip-layout module. Based on knowledge-based rules, the system is designed by considering several factors, such as radius and angle of bend, material and thickness of product, complexities of blank geometry and punch profile, and availability of press. This system is capable of unfolding a formed sheet metal part to give flat pattern and automatically account for the adjustment of bend allowances to match tooling requirements by checking dimensions and the best utilization ratio of blank-layout within bending production feasibility area which is beyond ${\pm}30^{\circ}$ degrees intersecting angle between grain flow and bending edge line and which is suitable to progressive bending operation. Also the strip-layout drawing generated by a bending and a piercing operation according to punch profiles divided into automatically for external area of irregularly shaped-sheet metal product is displayed in graphic forms.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.11
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• pp.171-179
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• 1997

This paper describes a nesting system of a computer-aided design of blanking and piercing for irregularly shaped sheet metal products. An approach to the system is based on knowledge-based rules. A nesting system is designed by considering several factors, such as utilization ratio which minimises the scrab for single or pairwise operation, bridge width, grain orientation and design requirements which maximise the strength of the part when subsequent bending is involve. Therefore this system which was implemented blank layout and strip layout module can carry out a nesting with a best utilization and a process planning for irregular shaped sheet metal products in single or pairwise operation and generate the blank layout and strip layout in graphic forms. Knowledges for a nesting and a process planning are extracted from plasticity theories, relevant references and empirical know-hows of experts in blanking industries. This provides its efficiency and effectiveness for nesting irregularly shaped sheet metal products.

• Transactions of Materials Processing
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• v.23 no.8
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• pp.501-506
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• 2014

Progressive shearing with blanking dies is commonly employed to produce large quantities of tiny sheet metal electronic parts. Sheet metal pins, which are narrow and long, that are sheared with a progressive die set are often twisted. The twist in the sheet metal pins, which usually occurs in the final shearing operation, generally decreases with increasing blank holding force. The blank holding forces in all shearing operations are not the same because of different shearing positions and areas. In the current study, the optimal layout of the springs in a progressive die set to minimize the twist of the sheet metal pin is proposed. In order to find the holding force acting on the tiny narrow blanks produced with the proposed springs during the shearing process, the equivalent area method is used in the structural analysis. The shearing of the sheet-metal pin was simulated to compute the twist angle associated with the blank holding force. The constraint condition satisfying the pre-set blank holding force from the previous shearing operations was imposed. A design of experiments (DOE) was numerically implemented by analyzing the progressive die structure and by simulating the shearing process. From the meta-model created from the experimental results and by using a quadratic response surface method (PQRSM), the optimal layout of the springs was determined. The twist of sheet metal pin associated with the optimal layout of the springs found in the current study was compared with that of an existing progressive die to obtain a minimal amount of twist.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1113-1118
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• 2008

Strip layout design in progressive die is an important factor that determines the applicability of mass production. In this study, the layout design of bracket strips used fer automobiles was executed. The strip layout design was made in 3D with the use of Cimatron die design, an automation module rather than a 3D modeling module. Blank layout has been optimized through a layer arrangement of the wide run positioning inside carrier (double-row and two-pass type). The 3D CAD/CAM software used was Cimatron Die Design; the strip layout design was completed in ten processes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.979-983
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• 2007

In this thesis, a strip layout drawing of LCD S/C (shield case) was prepared. In the press die, strip layout drawing is a major factor that decides the mass production of a product. The 3D CAD/CAM system was applied for the easy correction of the interference factor with other parts to be mounted. The material use ratio was enhanced to 60.17% by optimizing the blank layout and strip layout in double width array. Furthermore, the flatness of the product was made to fit the requirements by adding the bidding process intensively on the notching part where the occurrence of the change in shape is expected owing to the thin material. For the 3D CAD/CAM software, Unigraphics NX3.0 was used. The strip layout drawing was prepared in 12 processes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.569-573
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• 2008

In this thesis, the drawing was prepared for the strip layout of the pickup frame In the press die, the drawing for press layout is a major factor in determining the mass production of the product. The 3D CAD/CAM system was applied to easily correct interference factors with other parts to be mounted. This study improved the material utilization ratio to 28.49% by optimizing the blank layout and strip layout in wide-width arraying. The 3D CAD/CAM software used is Unigraphics NX 4.0, and the strip layout drawing was prepared in 12 processes.