• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.95-102
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• 2016

Wrinkle, spring-back, and fracture are major defects frequently found in the sheet metal forming process, and the reduction of such defects is difficult as they are affected by uncontrollable factors, such as variations in properties of the incoming material and process parameters. Without any countermeasures against these issues, attempts to reduce defects through optimal design methods often lead to failure. In this research, a new multi-attribute robust design methodology, based on the Mahalanobis Taguchi System (MTS), is presented for reducing the possibilities of wrinkle, spring-back, and fracture. MTS performs experimentation, based on the orthogonal array under various noise conditions, uses the SN ratio of the Mahalanobis distance as a performance metric. The proposed method is illustrated through a robust design of the sheet metal forming process of a cross member of automotive body.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.213-217
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• 1999

An expert system is developed for rational and efficient design of multi-component injection molding which is a fairly new manufacturing technique to produce plastic parts by injecting two or more materials sequentially using multiple injection units in a single machine into a single rotary mold. The knowledge base used in the present design system is primarily composed of two parts ; knowledge from domain expert and knowledge from CAE analysis. The present expert system has hour main modules ; general design guidelines for injection molding specific guidelines for multi-component injection molding redesign guidelines from the result of the CAE analysis and finally troubleshooting for multi-component injection molding. To show the validity of the present design methodology two shop floor design problems were tested ; design and fabrication of timing belt cover and power window's assist knob by using multi-component injection molding.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.60-66
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• 2021

This study aimed at identifying and optimizing the heating-condition parameters that cause surface defects during the compression molding of chalcogenide glass (GeSbSe) lenses through thermal analysis. We derived the optimal heating conditions for molding chalcogenide glass lenses through thermal analysis and analyzed the surface defects. As a result, we observed a significant reduction in surface defects, which verified the analysis process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.184-187
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• 2004

The sheet parts are formed with dies conventionally. But this conventional forming process is not suited to small volume and varied production for the reason of high cost. For the solution of this problem, a new forming process, which is called CNC incremental sheet forming, is being introduced. This process can form sheet parts without die, and is very well suited to small volume and varied production in space flight and automobile. In this paper, dieless CNC forming system based on a machining center is developed. A special device to grasp and pull the blank sheet built in the machining center and tool path generation S/W from STL file of 3-D model are developed. Several sheet parts are incrementally formed to verify the effectiveness of the developed system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.133-138
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• 2017

Recently, CFRP composites are widely used as lightweight materials have with excellent mechanical properties and can beare widely used in various fields. In general, thermosetting resins are used for CFRP. However, in recent years, studies have been carried out using thermoplastic resins have been actively carried out to overcome the disadvantages of thermosetting resins. The LFT-D system is a molding method in which a fiber is directly cut to a the desired length while being impregnated with a thermoplastic resin to produce a compound and that is then press-molding molded to form the product. In this paper, before the production of the trailing arm, the compression molding analysis was carried out in order to grasp the problems that may occur during production. Through cCompression molding analysis was applied to calculate of the minimum press pressure and to compare and analysis analyze the molding conditions characteristic required to formfor forming the trailing arm.

• 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 Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.192-195
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• 2003

최근 첨단기술 집약형 자동화 시스템과 정보기술의 발달에 따라 산업은 고도화, 정밀화되고 있다. 특히 안전분야 중 기능성 고분자 재료의 응용 분야로서 carbon black, carbon fiber, graphite, 금속 분말 등의 전도성 충전재를 고분자 matrix에 혼입하여 전도성 복합재료를 성형가공하는 기술이 개발되고 있다. 이를 이용한 복합성형체는 과전류 차단, 회로 보호, 전자파 차폐효과 등의 특성을 이용한 electrical hazard 감소 효과, 제어설비, 자동화 설비, 제조설비 등 각종 산업설비의 정밀제어, 과전류차단 및 외란 방지 등에 다양한 용도로 활용되고 있다.(중략)

• Journal of the korean Society of Automotive Engineers
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• v.19 no.1
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• pp.12-21
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• 1997

자동차의 제조과정은 크게 유니트 생산과 차체 조립으로 이루어 지고, 차체는 박판 성형에서 용접, 도장, 조립의 단계로 생산된다. 연간 수십만대 규모의 생산량을 갖는 자동차의 제조 시스템은 각 단계에 적절한 공장들로 구성되고, 이들은 각각 특성에 맞게 적정 수준의 생산성과 유연성, 그리고 원가 구조를 갖는 시스템을 보이게 된다. 본 고에서는, 자동차 생산의 시스템 전략적인 측면과 유니트 및 차체의 가공, 조립 시스템에 관한 기술현황을 사례 중심으로 고찰하고자 한다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.60-65
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• 2012

This paper deals with an CAE analysis and optimization of injection molding for a mobile phone cover. Two design goals are established in the optimization; one is to switch over the feed system from cold runner to hot runner for the purpose of reducing material costs, and the other is to minimize the warpage in order to improve product quality. By the full-factorial experiments for design parameters, we showed that the cold runner design could be changed to the hot runner design by replacing the current resin with a new resin of higher fluidity. In addition, we could significantly reduce the warpage of the cover product under the hot runner system by optimizing packing pressure and packing time.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.267-270
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• 2004

In Micro injection process, it is needed to the technique of making micro die, Rapid Thermal Pressing (RTP) and other techniques. Those techniques are independent. But the mutual connected system of techniques is needed. The target of this paper is the design of micro mold and the development of the entire micro injection techniques for functional polymer.