• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.142-145
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• 2004

More complex geometric shapes, including freeform surfaces, are adopted for the design of products to emphasize styling or aesthetics. Modeling of these products is extremely difficult, and often impossible. Reverse engineering is an emerging technology that can resolve this problem by generating CAD models from the physical mockups or prototype models. The laser scanner if often used to acquire the surface information of the part, but is limited in its measuring direction, which if fixed only along the z-axis. A Designed fixture of new shape to supplement these problems in this paper. The new fixture using several joints and an tooling ball holder is designed considering the convenience of the part set-up and the accuracy of the registration. The location of the tooling balls can be arranged to avoid the occlusion of the part and to minimize the registration error. The new fixture is apply to an object part having freeform surfaces to verify the effectiveness of the proposed design.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.323-327
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• 1993

Mold-making industry demands currently to reduce the tooling costs and time in mold making, and to improve the productivity and quality in injection molding process. These problems can be easily removed by laminated injection mold which is made with metal sheets prepared by laser cutting and bonded by brazing. Comparing withthe conventional mold making technology which mainly depends on the machining, this new technologyenables an arbitary design of cooling circuit without anyrestrictions of geometry. So it brings about high production rates of the injection molding processes. This paper estimate the conventional and laminated injection mold making process with a simple molding, and also the cooling efficiencyof thoes two kinds of mold with the filling and cooling analysis. The results show that the laminated injectionmold has much shorter tooling time, uniform mold temperature, and shorter cooling time in injection molding process.

• 소성∙가공
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• 제15권1호
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• pp.71-75
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• 2006

In recent, various shapes of pattern in micron or nano scale are adapted in many applications due to their good mechanical or optical properties. Light guide panel (LGP) of the LCD is one of important applications for micro pattern and micro prism shape is one of the typical patterns. The size of the surface patterns in most applications is decreasing to the order of micron or even under micron. On the other hand, the area to be patterned keeps enlarging. These two trends in patterned products require tooling micro patterns on large surface, which has still many technical problems to be solved mainly due to pattern size and the tooling area. In this study, we fabricated prism shape of patterns using diamond cutting tool on some metal core and plastic core like PMMA. Some cutting conditions were investigated including cutting force, cutting depth and speed for different core materials.

• 소성∙가공
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• 제10권6호
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• pp.500-508
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• 2001

The integration of Rapid prototyping (RP) and Rapid Tooling (RT) has the potential for rapid net shaping of thee-dimensional parts, which have a geometrical complexity. In this study, a new R)P process, (VLM-SP), was proposed to manufacture net shapes of three-dimensional prototypes and it was shown that VLM-SP is an effective and economic process through the comparison of building time, building cost and dimensional accuracy for the test parts with the commercial RP processes ; LOM and FDM. In addition, the metal parts, which are a spanner shape and a clover punch, were produced by the plaster casting as one of RT using the prototypes of VLM-SP.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.303-306
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• 2001

To shorten the delivery time for new products, a lot of prototype plastic parts manufacturing technologies have been developed including injection molding, vacuum casting, thermal forming and so on. Among them, RIM is becoming one of a important soft tooling methods to produce prototype and mass production parts within short time. Further more, as the rapid prototyping technology based tooling methods are playing an important role in prototype manufacturing industry, the utility of the RIM is increasing. But few analyses and mold design techniques have been developed so far due to its chemical and mechanical complexity during the packing and curing process. This research suggests mold gate design criteria to prevent bobbles from molded parts through simplified mathematical model and change of bubble sizes according to the geometry of the molded parts through experiments. Also this study shows the differences of bobble generation mechanism between RIM and injection molding.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.183-188
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• 2002

Co-cured composite materials has its own characteristics, so its thermal expansion is different each other. The selection of tool material for co-cured composite part in high temperature more over $350^{circ}F$ and 50 Psi pressure have to consider part thermal expansion, size, shape, and economic aspect in production line. So it is important choose tooling material in manufacturing composite parts. We called the tool for airplane composite parts as BAJ (Bonding Assembly Jig). Composite parts are cured on the BAJ in autoclave. BAJ have to stable at high temperature over $350^{circ}F$ and 50 Psi pressure, Considering composite parts' dimensional tolerance compare to heat up in autoclave. This paper come from the results of the experiment at the composite parts production line and review other aircraft company's method for tooling This is for the engineer engaged in composite parts manufacturing.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.651-657
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• 1996

Industrial products are getting more and more complex. The number of parts or components and the variety of manufacturing processes are increasing. This leads to rapid product oriented machine tools. The process integrated CNC lathe is one of the these machine tools which can produce numerous parts and various machining processes and reduce the lead time and non-machining time. Therefore this study deals with the design technique of a process-intergated CNC lathe which can reduce the tact time and production cost by the speed-up of the tooling system and the high-speed machining oriented construction of 2 spindles and 2 turrets.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1257-1260
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• 2003

Rapid Prototyping technology has many advantages such as Rapid Tooling. However, Using the RT technique is limited by the poor surface quality of the RP part. Thus, additional post-machining is required for improving the surface roughness by the sanding, grinding and polishing etc. But, these traditional finishing techniques are time and labor cost consuming. Hence, improving and formulation the finishing technique is inevitably necessary for the RF part. A new post-machining methodology for RP part is presented by the SLS part is used for automobile components in this research. Also, a web based interface tool that user requirements are rapidly ordered for post-machining RP part is developed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.428-432
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• 2003

The technical combination of RP and RT has a potential for rapid manufacturing of three-dimensional parts. In the present work a new RP system, $VLM-_{ST}$, is proposed to manufacture net shapes of 3D prototypes. ㅁ human head shape and a kob shape are manufactured by the $VLM-_{ST}$ apparatus. In addition, a new RT technology, which utilizes a RTV molding technique and a triple reverse process technique, is proposed to manufacture net shapes of 3D plastic parts using prototypes of $VLM-_{ST}$. A plastic part of the knob shape os produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacturing of a plastic knob within two days.

• 한국CDE학회지
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• 제8권2호
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• pp.47-52
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• 2002

레이저를 이용한 직접금속성형기술(영문명 : DMT: Direct Metal Tooling)은 고 부가가치의 기능성 소재(금속, 합금, 세라믹 등)의 미세한 분말을 원하는 3차원 공간상에 주사함과 동시에 이를 레이저로 직접, 순간 용착시키며 이것이 공간상에서 축적되가면서 미리 정해진 3차원 파트형상이 자동적으로 빌드업 되도록 하는 고도의 정밀제어 기술을 요하는 신기술이다. 이는 컴퓨터에 저장된 3차원 디지털 형상정보(digital data of 3D subjects)만 갖고 있으면 이로부터 그에 해당하는 금속파트형상을 적절히 소재분말을 이용하여 곧바로 실물로 재현하여 얻을 수 있게 됨을 의미하며 이로서 기존에 절삭기계를 이용한 가공 공법보다 손쉽고 빠르면서도 반면 기계적 성질은 종전기술보다 월등히 우수한 B차원 금속 파트나 금형 형상을 소재의 낭비가 전혀 없는 환경 친화적인 방법으로 제작할 수 있는, 소위 밀레니엄시대를 대표하는 최첨단 미래형 기술의 구현이다.