• Design & Manufacturing
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• v.14 no.2
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• pp.49-55
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• 2020

Recently, when a new component of construction equipment is designed, a stamping process capable of producing parts having high appearance quality and precision has been gaining attention. However, in general, as it is developed based on existing parts made by welding metal sheets and tubes, frequent to die modification occurs, which increases the time and cost of developing new parts. Thus, it is necessary to reduce the cost by shortening the die development period. In this study, a stamping process was designed for the urea tank cover, which is a part for excavators, to reduce the die development period through sheet metal forming analysis. The stamping process was designed by determining the blank holding force after selecting the initial blank shape and size. The round value at the corner was modified such that formability is ensured. After selecting process parameters, the thickness reduction rate and spring-back effect were reviewed.

• Journal of the Semiconductor & Display Technology
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• v.18 no.3
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• pp.12-18
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• 2019

The protective double layer polymer coatings on silica optical fibers are realized by wet-on-wet liquid coating process and they play an important role in final quality of mass produced optical fibers. This numerical study aims to analyze the effects of secondary coating die design parameters by employing two dimensional axisymmetric model of coating cup and coating die geometry and computational fluid dynamics simulations which include temperature dependent viscosity of polymer coating liquids and viscous dissipation heating. Under high speed fiber drawing conditions and pressurized coating liquid supply, the effects of converging die angle are investigated in order to appreciate the change of coating liquid flow patterns such as flow recirculation zone near coating die as well as primary and secondary coating layer thicknesses. The auxiliary coating die to converging coating die is also tested and the results find that this concept is advantageous in achieving stable double layer coatings on silica glass fiber.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.124-133
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• 1998

This paper describes a research work of developing a computer-aided design of blanking and piercing for irregular-shaped sheet metal products. An approach to the development of compact and practical CAB 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. Based on knowledge-based rules, the system, STRT-DES, is designed by considering several factors, such as complexities of blank geometry and punch profile, availability of press equipment and standard parts, utilization ratio which minimizes the scrap in a single or a pairwise operation, bridge width, grain orientation and design requirements which maximize the strength of the part when subsequent bending is involved. This system checks a forming feasibility with both internal and external features, a dimension of blanked hole, and a corner and a fillet radius for irregualrly shaped sheet metal products. Therefore this system can carry out a die design for each process which is obtained from results of an automated blank layout drawing with a best utilization ratio for irregular shape of product that was successful in production feasibility check module and those of an automated strip layout drawing and generate part drawings and the assembly drawing of die set in graphic forms.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.216-219
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• 2001

The production of fine wire through multi-pass wet wire drawing process would be impossible with no backtension at inlet of dies. Backtension is affected by many process parameters, such as dies reduction, coiling number of wire at capstan, machine constant, slip between wire and capstan, characteristic of lubricant and so on. Up to date, dies design and dies pass schedule of multi-pass wet wire drawing process have performed by trial and error of expert in the Industrial field without consideration of quantitative relation among process variables. Thus study investigates the multi-pass wet wire drawing process considering the relation among process variables, such as dies reduction, coiling number of wire at capstan, machine constant, slip between wire and capstan, etc. And analysis program which can analyze many important process values(drawing force, backtension force, slip rate, slip velocity rate, etc) for die design and dies pass schedule of multi-pass wet wire drawing process was developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4108-4114
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• 2010

The automation of the machining and manufacturing process of press die is designed to shorten the working time by avoiding unnecessary repetitive works and to obtain subject articles with standard quality. Automation as used in this paper includes 3-D die design, machining center, wire-cut electrical discharge machining, and drawing works. This paper deals with research work on the automation of the machining and manufacturing process of the press die after 3-D die design using the Irp bracket for the control box sensor. The research was conducted under the same setting as that of die design.

• Transactions of Materials Processing
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• v.12 no.3
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• pp.236-243
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• 2003

Maintaining the required dimensional accuracy after springback becomes the main concern of sheet-forming die designers when formability is secured through beforehand tryouts. As a part to build guidelines for springback control in automobile frame forming, experiments are carried out to show the effects of process parameters, such as holding force, blank size, and lubrication, on corner angles of channels formed by U-bending or by square-cup drawing and trimming. The results predicted by a commercial FE package were compared with the experiment and the current limitations on springback evaluation were closely discussed.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.105-109
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• 2001

성형의 종류 ◈금속 성형 ㆍ 스탬핑(Stamping) ㆍ 정밀 블랭킹(Fine Blanking) ㆍ 딥 드로잉(Deep Drawing) ㆍ 다이캐스팅(Die Casting) ㆍ 인베스트먼트 주조(Investment Casting) ㆍ 분말 야금(Power Metallurgy) ㆍ 인발(Wire Drawing) ㆍ 압출(Extrusion) ㆍ 단조(Forging) ㆍ ㆍ코이닝(Coining) ㆍ... ◈비금속 성형 ㆍ 사출(Injection) ㆍ 압축(Compression) ㆍ 블로우 성형(Blow Molding) ㆍ 진공 성형(Vacuum Molding) ㆍ 발포 성형(Foam Molding) ㆍ 피복(Encapsulation) ㆍ 회전식(Rotational) ㆍ 주조(Casting) ㆍ 적층(Laminating) ㆍ 압출(Extrusion) ㆍ...(중략)

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.13-27
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• 1996

소성가공이란 원재료를 소성변형(Plastic deformation)을 통해서 고체의 제품을 만드는 가공법이다. 가공중에 물체의 질량과 체적에는 크게 변화가 없다. 소성 가공중 주응력이 어떻게 작용하느냐에 따라서 소성가공을 여러가지로 분류하고 있다. 즉, Metal Forming은 다음과 같이 분류할 수 있다. 1) Compound Forming에는, Rolling, Free forming, Die forming, Stamping, Pressing 2) Tension compression forming에는, Drawing, Deep-drawing, Rimming, Spinning, Bulge forming 3) Tension forming에는 Lengthening, Widning, Deepening 4) Bending에는 Bending with linear tool motion, Bending with rotary tool motion 5) Thrust forming에는 Swaging, Twisting이 있다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.90-93
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• 2002

Assuring required dimensional tolerance after spingback becomes the main concern of sheet-forming die designers when formability is secured through previous tryout. As a part to build a guideline to control springback in automobile frame forming, experiments are carried out to show the effects of process parameters, such as holding force, blank size, and lubrication, on corner angles of channels formed by U-bending or by square-cup drawing and trimming. The results are resented in the viewpoint of evaluating parameters.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.10a
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• pp.157-164
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• 1994

Finite element analysis of material deformation is successfully utilized to understand metal forming processes such as forging, extrusion and deep drawing. However, such analysis involves contact problems; a free node touches a die surface and a contact node slips along the die surface. In the present investigation, appropriate contact algorithms were developed assuming that a three dimensional surface can be divided into bilinear patches and that nodal velocities are linear during an incremental time. The algorithms were coded into a computer program and tested for a simple surface. Comparison of the test result with that obtained from a commercial code is presented and discussed.