• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.812-815
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• 2000

Injection molding process was taken to manufacture DC motor case that surrounds DC motor used as automobile parts. Up to now, DC motor case has been made by the deep drawing process or bending process of metal materials. Simulations of filling, packing and cooling processes were done by CAE tool like Moldflow software. Optimal delivery system was decided from the analysis of flow balance, and packing and cooling analyses were performed by using the design of experiment to minimize the volumetric shrinkage of molded part and the temperature difference between mold and part.

• The Korean Journal of Rheology
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• v.6 no.2
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• pp.104-118
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• 1994

단섬유 보강 플래스틱 재료의 사출성형 충전공정에서 금형재의 유동장이 섬유 배향 상태를 형성하는데 중요한 역할을 할 뿐만 아니라 섬유의 배향상태가 역으로 유동장에 영향 을 미친다. 충전유동과 섬유 배향의 연계해석을 위하여 단섬유에 의한 추가적인 응력을 포 함하는 Dinh과 Armstrong의 이방성 구성방정식을 충전유동의 해석에 도입하였다. 평명방향 으로의 속도구배에 의한 응력을 고려하여 새롭게 유도된 압력 지배방정식과 에너지방정식을 유한요소법과 유한차분법을 이용하여 풀고 동시에 2차배향텐서의 변화방정식을 4차 Runge-kutta 방법을 이용하여 풀었다. 절점 게이트 주변의 확장유동영역과 라인게이트를 통한 수축유동영역에서 평면방향으로의 속도구배에 의한 응력이 유동장에 미치는 영향을 고 찰하였다. 확장유동영역에서는 평면방향으로의 속도구배에 의한 영향이 추가적인 유량으로 나타나면서 주어진 유량조건하에서 평면방향으로의 속도구배에 의한 응력을 고려하지 않은 경우보다 작은 압력구배를 나타냈다. 수축유동영역에서는 위와 반대의 결과를 보였다. 이러 한 경향은 섬유의 부피분율이증가하거나 모양비가 커짐에 따라 증가한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.279-280
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• 2006

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.69-73
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• 2008

본 연구에서는 고분자 플라스틱 부품의 친환경 외장성형공법인 Insert Film 사출성형공법중 첫 번째 공정인 진공성형공정에서 진공금형의 표면온도 균일화 기술에 대해 연구를 수행하였다. 진공금형의 온도분포 균일화를 위한 금형설계 및 설계된 금형에 대한 온도분포 평가를 위한 ANSYS를 이용한 유한요소열해석을 수행하였으며, 이때 정상상태 및 과도상태를 함께 평가하였다. 설계 결과를 바탕으로 금형을 제작하였으며, 생산성을 고려하여 4캐비티로 제작된 금형에 대해 금형표면의 온도분포 평가실험을 수행하였다. 또한 금형내 캐비티 온도센서 및 제어시스템을 설치하여 진공금형표면 온도분포가 항상 일정하게 유지될 수 있도록 금형시스템을 개발하였다. 결과적으로 일정한 온도범위의 금형표면온도제어가 가능하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1933-1947
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• 1991

The synthesis of supplementary features of injection molded parts has been done empirically, since it requires profound knowledge about the features' moldability and causal effects on the properties of the part, which are not available to designers through current CAD systems. RIBBER is a knowledge module which contains knowledge to permit non-experts as well as mold design experts to generate acceptable supplementary features of injection molded parts. A knowledge-based CAD system is constructed by adding the knowledge module, RIBBER, for mold feature synthesis and appropriate CAE programs for mold design analysis to an existing geometric modeler in order to provide designers, at the initial design stage, with comprehensive process knowledge-based CAD system is a new tool which enables the concurrent design and CIM with integrated and balanced design decisions at the initial design stage of injection molding.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.533-536
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• 2011

기어는 중요한 핵심 기계요소 중 하나로서 기계적 물성이 강화된 엔지니어링 플라스틱의 개발과 제품의 성능 향상 및 소형화, 경량화, 저소음화 등의 소비자 요구를 만족시키기 위한 노력에 편승하여 정밀도가 높은 플라스틱 기어에 대한 생산 요구가 증대되고 있는 실정이다. 본 논문에서는 시력 측정 장치인 자동굴절검사기용 디스크 기어에 대하여 변형을 최소화하기 위한 성형조건 최적화를 수행하였다. 사출 공정의 주요 공정변수를 사출온도, 충진시간과 보압압력, 금형온도로 정하고 다구치 방법에 의해 성형 해석으로 예측된 변형량을 분석한 결과 사출온도와 보압압력이 원판형 기어의 Z방향 변형에 가장 큰 영향을 미치는 것을 알 수 있었다.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.983-988
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• 2004

In the present study, the effects of orthogonal ribs on structural warpage during injection molding process were investigated. Basic ribbed models for the evaluation of degree of warpage were introduced and designed. Injection molds for these models are manufactured based on the full 3D CAD/CAM technology and specimens are prepared for experiment. Numerical analysis using commercial plastic injection molding analysis software was also performed to compare the results with experimental ones. The variations of materials and parameters such as injection time, mold temperature, melt temperature, holding time were considered in the present work. It was shown that orthogonal ribs have significant effect on the reduction of warpage during the injection molding process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.109-114
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• 2005

The large injection molded parts technology such as instrument panel, front and rear bumper are presented for a precision molding. Some lead time and cost are required to product these part from design to mass product. Recently, CAE is widely used in product design, mold design and analysis of molding conditions to reduce time and cost. The optimal molding conditions can be obtained by DOE(Design of Experiment). The optimal design applications with CAE and DOE have been used in small molded parts. However, application to the large molded body is not reported. In this paper, optimization of injection molding process is studied for quality control in mass production of automobile bumper. Mold temperature difference is chosen through robust design of injection molding process, the molding process being optimized in term of shrinkage and deflection. The optimal conditions through DOE are validated by using injection molding analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1494-1499
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• 2008

Plastic materials are utilized to the most important material of automobile interior-parts due to special characteristics that it is light, good strength and do not transmute quality even if pass long time. This study presented a preliminary analysis of fill time, weld line, air trap etc. for the plastic injection molding process of automobile gearbox cover through simulation using Moldflow.

• Polymer(Korea)
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• v.33 no.6
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• pp.561-568
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• 2009

Small injection molded articles are generally molded by multi-cavity injection molding. The most important thing in multi-cavity molding is flow imbalance among the cavities because it affects the physical property and the quality of products. The cavity filling balance can be achieved by flow balance in the runner through the thermal balance. In this study, novel screw type runner or helical type runner has been developed for the flow balance in the runner and performed experiment and computer simulation. Flow balance has been observed using various screw type runners for several resins such as amorphous and crystalline polymers including low and high viscosities grades. Flow balance experiments have been performed for various injection speeds since the flow balance can be affected by injection speed among the injection conditions. Experimental results have been compared with computational results and they showed good agreement. The cavity filling balance can be achieved by the screw runner where the temperature distribution is uniform through the circulation flow along the screw channel in the screw runner. It has been verified that the novel screw runner is very effective device in flow balance in the multi-cavity injection molding. cavity filling imbalance, multi-cavity injection molding, runner design, screw runner, thermal balance.