• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.1012-1016
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• 2002

This paper describes a research work of developing computer-aided design of a product with bending and piercing for progressive working. An approach to the system for progressive working 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. The system has been written in Auto-LISP on the Auto-CAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, strip layout, and die layout modules. The system is designed by considering several factors, such as bending sequences by fuzzy set theory, complexities of blank geometry, punch profiles, and the availability of a press equipment. Strip layout drawing generated in the strip layout module is presented in 3-D graphic forms, including bending sequences and piercing processes with punch profiles divided into for external area. The die layout module carries out die design for each process obtained from the results of the strip layout. Results obtained using the modules enable the manufacturer for progressive working of electric products to be more efficient in this field.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.146-154
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• 1996

In this work, rapid prototyping and three-dimensional finite element analysis are simultaneously applied to the die design of metal forming processes. Rapid prototyping is a new prototyping technology which produces three-dimensional part models directly from CAD data and has been extensively applied to various manufacturing processes. There are many types of rapid prototyping systems due to their building principles and materials. In this work, Stereolithography Apparatus(SLA), which is the most widely used rapidprototyping system, is introduced to manufacture the die set. For general preparation of STL file, which is the standard input file of rapid prototyping system, mesh data which are used in describing the die surface in finite element analysis are translated so that rapid prototyping and finite element analysis are dffectively connected. A die set for spider forging and a clover punch for deep drawing section are manufactured effciently using SLA prototypes, and metal forming experiments are carried out using them. Comparing the result of experiments with that of analyses, the processes can be predicted and designed successfully.

• Korean Journal of Computational Design and Engineering
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• v.9 no.4
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• pp.373-381
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• 2004

Using standard components of a press die is recognized as a way for a cost reduction and a short lead time. It also provides a way for a quick maintenance of a die under repair. It is expected to contribute to integration of CAD/CAM system for manufacturing dies in the future. This paper presents a 3D CAD library which is constructed using the standard components and is used for designing a press die. This 3D CAD library is generated by a database system made of Microsoft Access for standard components and by CATIA V5 R10 API for geometric features. The library is implemented using Visual Basic 6.0 utility of CATIA API function in the Windows NT environment. It creates a 3D model of the standard components of press die easily when a die designer inputs numerical values of geometric features and the BOM of the completely assembled parts. It also generates automatically the assembly drawing of die set by using variables for standard values of die parts. Therefore users can save the cost of time to design the press die components, and even a beginner can use this program with ease. The test results of the 3D CAD library for designing shearing and bending dies verify its usefulness and feasibility.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.131-141
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• 2004

In this study a 3-D automatic die design supporting system for a bonnet panel has been developed using Pro/ROGRAM of the widespread CAD software Pro/ENGINEER A standard drawing die was defined in terms of the punch profile, the die face geometry, and the blank sheet size. The strip layout of a trimming die was defined, in addition, in terms of the trimming line and the locations of scrap cutters. Necessary relations for each design step are formulated and rules for bottom-up type 3-D die design were set up for the automatic design of drawing and trimming dies of a bonnet. With the input geometric data of punch profile, die face, and blank sheet, this 3-D design supporting system could complete the basic design process, in case of the bonnet drawing die, in a time 78% shorter than that required by a typical 2-D CAD system. The new design system showed remarkable design efficiency also when it was applied to the case of redesign and modification of the previous standard output for a different car type.

• Journal of Korea Foundry Society
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• v.35 no.4
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• pp.80-87
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• 2015

The Al die casting process has been widely used in the manufacturing of automotive parts when the process requires near-net shape casting and a high productive rate. However, porosity arises in the casting process, and this hampers the wider use of this method for the creation of high-durability automotive components. The porosity can be controlled by the shot condition, but, it is critical to set the shot condition in the sleeve, and it remains difficult to optimize the shot condition to avoid air entrapment efficiently. In this study, the 4.5 mm, 2.0 mm plate die castings were fabricated under various shot conditions, such as plunger velocities of 0.7 m/s ~ 3.0 m/s and fast shot set points of the cavity of -25%, 0%, 25%, and 50%. The mold filling behavior of Al melts in the cavity was analyzed by a numerical method. Also, according to the shot conditions, the results of numerical analyses were compared to those of die-casting experiments. The porosity levels of the plate castings were analyzed by X-ray CT images and by density and microstructural analyses. The effects of the porosity on the mechanical properties were analyzed by tensile tests and hardness tests. The simulation results are in good general agreements with the die-casting experimental results. When plunger velocity and fast shot set point are 1.0 m/s and cavity 25% position, castings had optimum condition for good mechanical properties and a low level of porosity.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.5
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• pp.22-33
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• 1997

This paper describes a research work of developing a computer-aided design of blanking and piercing for stator and rotor parts. Based on knowledge-based rules, the die design system, STRTDES2, is designed by considering several factors, such as complexities of blank geometry and punch profile, and availability of press equipment and standard parts. Therefore this system can carry out a die design for each process which is obtained from the result of an automated process planning system, STRTDES1 and generate part drawing and the assembly drawing of die set in graphic forms. Knowledges for die layout are extracted from plasticity theories, relevant references and empirical know-hows of experts in blanking industries.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.370-373
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• 2008

It is known that the temperatures of die, punch, holder and punch pad need to be kept different to get better formability in Mg sheet forming processes. Heating and cooling channels are usually equipped in each tool to assign different temperature. This study focused on the optimal design of the heating and cooling channels for a cross-shaped deep drawing die set. While the die and blankholder were heated to and kept at $250^{\circ}C$ by using heat cartridges, the punch and punch pad were kept at much lower temperature than that of the die and blankholder by water circulating through cooling channels. All the approaches were done by numerical analyses, aiming to maximize the cup height and to minimize the punch corner radius without any failure.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.94-106
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• 2003

In recent years, the production value of Taiwanese mold and die industries have reached to a high peak in 1998, in amount of NT 604 hundred million dollars. But in recent years production value are going down year by year, till year of 2001 the production value have down to NT 394 hundred million dollars. Its main reason might be the major product were following in medium and low price category, the high accuracy and high cost mold and die still rely on import aboard. Therefore how to made the related technical database system on various field to provide the industry user to promote industries competition ability in mold and die is really urgent matter at this moment. In this research, we will offer how to apply the Visual Basic program language to edit a set of more perfect database system of mold and die material selection. At the present time, we have constructed complete Knowledge-Base-System of intelligence for forging mold and die material, the most related data from the existed data, the others are through our additional experimental results. By using this system by the user can got the related and need data easily, we hope it will reduce designing time and cost for mold and die.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.303-306
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• 2000

This paper describes a research on the development of the 3D design automation system for progressive die. Based on knowledge base of expert, this system can carry out design tasks, such as feature recognition of product data, layout design, dre set component design. Easy system user mterface and 3-dlmensional solid modeling could result in time and cost saving.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.66-69
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• 1999

This study aims at the improvement on the process and die set required for forming of flanged two-piece thrust engine bearings form laminated sheet blanks. Several suggestions are made to reduce the number of forming or subsequent machining processes or to improve the dimensional precision of formed products. The results of finite element analysis show the design suggested in this study are useful and applicable to the forming process of flanged bearings.