• Journal of the Korean Society for Precision Engineering
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• 제18권1호
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• pp.63-73
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• 2001

This paper presents a process and operation planning system with an NC code post-processor for effective machining of press dies for production of cars. Based on the machining features, major parts of press dies are categorized into 15 groups and a standard process plan is defined for each group. The standard process plan consists of a series of processes where a process is defined as a group of operations that can be done with one setup. Details such as cutting tools, cutting conditions, and tool paths are decided at the operation planning stage. At the final stage of process and operation planning, the NC code post-processor we developed adjusts feedrates along the tool path to reduce machining time. The adjustment rule is selected based on the metal removal rate estimated by virtually machining with virtual cutting tool.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제18권2호
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• pp.349-355
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• 2017

Bending work using press dies involves bending a flat blank to a desired angle. The bending produces a flange (the bent part) and a web (the unbent part). The bending line will have a bending angle, and there is an inner and outer bending radius. The minimum inner radius size is determined by the material used. When the inner radius size is too small, there will be excess metal welding, which will cause a crack in the outer radius part. The outer bending radius size cannot be controlled by a bending punch and die block. Types of bending include V-bending, U-bending, O-bending, edge bending, twist bending, and crimping. Z-bending involves two bending lines, which are set on the upper side and under surface of the blank, respectively, and upward or downward bending is used. Z-bending is also called crank bending. Z-bending using this type of die structure will produce a standard inner bending radius. The standard size is the minimum bending radius that represents the angle radius of the bending punch. In industry, there is a need for a sharp edge shape with a very small size (R=0.2mm), but that is not possible when using bending punch and die block. The purpose of this research is to meet the need by development.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1416-1419
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• 2005

Design and manufacturing of plastic injection mold with cavity pressure/temperature sensors were performed in the present study for tensile test specimen. Standards of mold-base and tensile test specimen were used to design an injection molding system. Cavity pressure and temperature sensors were placed on the side of fixed platen of injection mold machine to prevent them from external impact damage. Injection molding experiments with variations of injection speed and melt temperature were performed and polycarbonate tensile specimens were prepared for the tensile test. It was shown that injection molding processing parameters can have effect on the mechanical properties of the plastic injection molded part.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.349-353
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• 1993

공정게획은 일반적으로 숙련된 공정계획자에 의해 결정되는 데 공정계획자의 육성및 보급이 어려우므로 자동공정계획시스템의 필요성이 대두되었다. 지난 80년대에는 공정계획자의 지식에 의존한 공정계획의 알고리즘 개발에 치중하였지만 실용적인 측변에서 효율이 떨어지는 관계로 산업계에서 외면당하는 경우가 종종 발생하였다. 이러한 문제를 해결하고자 본 연구에서는 AutoCAD로 부터 자동 또는 대화식으로 부품의 형상 및 치수데이터를 인식하여, 이 데이터를 기준 으로 최적의 공구선정이 가능하게 데이터베이스를 구축하였다. 공작물의 크기에 따라 적절한 공작기계의 선정이 가능하도록 하였으며, 공구의 이동속도는 회귀분석방법에 의해 재질별로 구분하여 표준작업시간 계산규칙 및 알고리즘을 개발하였다

• Journal of the Korean Society for Precision Engineering
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• 제24권11호
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• pp.84-90
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• 2007

In this study, design and manufacturing of plastic injection mold with cavity pressure/temperature sensors were performed fur tensile test specimen. International standard system for plastic tensile specimen was applied to design an injection molding system. Cavity pressure and temperature sensors were placed on the side of fixed platen of the injection mold to prevent them from external impact damage. Injection molding experiments with variations of injection speed and melt temperature were performed and then tensile test of the manufactured polycarbonate specimens was also performed. It was shown that injection molding processing parameters can have effect on the mechanical properties of the plastic injection molded part.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1992년도 추계학술대회 논문집
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• pp.111-114
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• 1992

과거 사출금형 설계 및 성형은 대부분의 단편적인 경험에 의존하여 왔으며 이는 단납기, 고품질화에의 대응에 있어서 가장 큰 문제점중의 하나로 인식되어 왔다. 그러나 최근에는 컴퓨터의 성능이 급격히 향상되고 보편화되면서 대기업을 선두로 한 컴퓨터 시뮬레이션이 활발히 응용되고 있으며 이는 앞으로 더욱 활성화될 전망이다. 본 연구에서는 사출성형 자동평가 시스템을 개발하였으며 이는 전처리 모듈, CAE해석 모듈 및 자동분석 모듈, 후처리 모듈등으로 구성되어 있다. 본 시스템에서는 주입장치 설계 표준 DATA BASE가 구축되어 있으며 특히 설계자가 설계 및 성형조건에 대한 기준만 정의하면 그 이후의 모든 평가 및 최적조건이 자동으로 계산, 도출될 수 있도록 하였다. 이번에 개발한 시스템에서의 핵심기술은 수치해석을 응용한 고분자 가공공정해석기술, 최적화 기술, DATA BASE구축기술 그리고 컴퓨터 그래픽 기술 등으로 위에서 언급한 바와 같은 사용시스템이 갖고 있는 현장 활용시 문제점들을 근본적으로 해결하여 차별화 시킨 것이다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.444-447
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• 2005

Increasing competition is due to internationalization in market. This result requires various products in a rapid development of product. Die design is one of bottleneck areas in product development. It takes 40% of total time for whole car development. Therefore a new method should be developed as a fundament on which the design process of die can be carried out effectively. This can be realized by using modular design based on standard template. In this paper a modular design concept will be discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제13권9호
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• pp.3815-3821
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• 2012

The LCD frame is an important part which supports the BLU of medium/large sized TFT-LCD. To produce it efficiently, it is necessary to achieve the molding process improvement from 1 cavity to 2 cavity system. Because 2 cavity mold is compact and its hot-runner zone is broadened, it is difficult to control the temperature on the mold. In this study, injection molding analysis on the frame in 2 cavity process with FEA(Finite Element Analysis) software is carried out to estimate its quality. The calculated injection molding pressures and maximum deflection in 1 and 2 cavity processes are 41.13 MPa and 1.62 mm, 40.49 MPa and 1.66 mm respectively. The measured maximum flexure load and surface roughness of the left and right frame of 2 cavities are 209 N and 0.08 ${\mu}m$, 193 N and 0.10 ${\mu}m$ while those in 1 cavity are 140 N and 0.13 ${\mu}m$. Thermal image shows that the maximum standard deviation of the temperature on left and right side of 2 cavity mold is $1.23^{\circ}C$. The simulation and measurement results show that the quality of the frame in 2 cavity injection molding process as a whole is not worse than that of 1 cavity system. But maximum flexure loads of the frame in 2 cavity process are far greater than that in 1 cavity process.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제32권1호
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• pp.25-32
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• 2022

Investment casting is a production method commonly used to manufacture precision equipment, medical fields, and accessories, and has continued to develop through the modernization of equipment and high quality of materials, and its scope of use has been expanded. The purpose of this study is to minimize the defect rate by deriving structural improvement and standardization of mold temperature, which are key elements of the investment casting process, to minimize the defect rate. The scope of the study is limited to jewelry manufacturing casting processes suitable for understanding the structure and principles of small gate, and an experimental research is to be conducted by using soft Wax, gypsum powder, and 14 K gold as research materials. According to the results, the most appropriate casting standard temperature for the casting pattern of Alloy 14 k was the lowest turbulence at 980℃ flask temperature of 550℃, so good products could be produced. As a future task of this study, detailed studies are needed to data the structure and system temperature of small gate, reduce production defects in the field, and provide data for excellent investment casting competitiveness.

• Transactions of Materials Processing
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• 제24권3호
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• pp.167-175
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• 2015

In the current study, the design methodology has been developed to produce shoe mold for a suitable walking shoes of the general Korean using ANN (Artificial Neural Network). To design the suitable and comfortable shoes for the Korean, the shapes of foots were measured for 513 people. In this research, the foot length, breadth and ankle were considered as design parameters. In order to find the optimal foot shape for the average value of design parameters, the average value of design parameters and the other measurements were used as input and output to the ANN. After training, the various foot measurements were predicted by ANN. Base on the ANN results, the walking shoes were manufactured by considering these measurements and designing a shoe mold. From the results, the proposed method could give a more systematic and feasible means for manufacturing walking shoes with greater usefulness and better generality.