• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.53-54
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• 2008

• Design & Manufacturing
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• 제17권3호
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• pp.21-27
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• 2023

The mold industry in Japan, an advanced country in the mold industry, is also at a point of great change. The main causes are the Ukraine crisis and the collapse of the global supply chain (parts supply chain) caused by COVID-19. In addition, the prices of overseas products are rising sharply due to rapid exchange rate fluctuations (decrease in the value of the yen). Until now, Japan's monotsukuri industry has been actively pursuing overseas expansion, riding the trend of globalization. However, the trend began to rapidly reverse, and now the monotsukuri industry that had expanded overseas is showing a tendency to return to Japan. Another factor of change is the change in the automobile industry, which is the most demanded product in the mold industry. As the automobile industry evolves from gasoline cars to electric cars, the number of parts that make up a car will drastically decrease. This trend is expected to increase the demand for small-scale production of a variety of products in the mold industry, and furthermore, it is expected that short delivery times will be required in parts development. As in Korea, the production population working in the mold industry is rapidly decreasing in Japan as well. Even if you add up the total population working in manufacturing in Japan, it only accounts for about 15%. Even in Japan, it is judged that it will be difficult to sustain the monotsukuri industry with this small production population. Therefore, since improvement in production efficiency cannot be expected with the same manual dexterity as before, the mold industry is also demanding the development of mold technology at a different level than before to increase productivity. In this paper, I would like to introduce new Japanese mold technology collected through attending the Intermold exhibition. This is an example of applying a dedicated pin (Gastos) to a mold to prevent an increase in internal pressure during plastic injection molding, and a deep drawing press molding technology with an inherent hydraulic function.

• 한국산학기술학회논문지
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• 제11권5호
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• pp.1552-1557
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• 2010

파워 윈도우 모터 조립부위에서 실린더 기어는 자동차 도어에서 중요한 부분이다. 이 연구는 대량 수입과 6 캐비티 금형 설계를 대체할 자체 제작 기술력 확보를 위해 수행되었다. 이 연구는 5가지 구체적 주제를 두고 작성되었다. 첫째, CAE를 이용해 시작품을 제작하고, 대량생산 제작을 위해 사전에 해석한다. 둘째, 대량생산 금형(2차원 및 3차원)을 설계한다. 셋째, 샘플 금형을 제작한다. 넷째, 3차원 설계제품을 시제작 후 측정한다. 다섯째, 데이터를 해석하고 금형을 수정한다. 이들 연구를 수행하면서 CAE를 사용한 제품샘플과 대량생산의 해석과 다수 캐비티의 샘플 금형의 제작의 연구가 성공적으로 수행되었다. 결과적으로, 핫런너를 사용하는 일점 게이트 및 6 캐비티가 파워 윈도우 모터 용 실린더 기어를 만드는데 가장 적합한 방법임을 알게 되었다.

• Design & Manufacturing
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• 제15권1호
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• pp.66-71
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• 2021

In this study, die turning injection(DTI) mold design for manufacturing reservoir fluid tanks used for cooling in-vehicle batteries, inverters, and motors was conducted based on multi-field CAE. Part design, performance evaluation, and mold design of the reservoir fluid tank was performed. The frequency response characteristics through modal and harmonic response analysis to satisfy the automotive performance test items for the designed part were examined. Analysis of re-melting characteristics and structural analysis of the driving part for designing the rotating die of the DTI mold were performed. Part design was possible when the natural frequency performance value of 32Hz or higher was satisfied through finite element analysis, and the temperature distribution and deformation characteristics of the part after injection molding were found through the first injection molding analysis. In addition, it can be seen that the temperature change of the primary part greatly influences the re-melting characteristics during the secondary injection. The minimum force for driving the turning die of the designed mold was calculated through structural analysis. Hydraulic system design was possible. Finally, a precise and efficient DTI mold design for the reservoir fluid tank was possible through presented multi-field CAE process.

• 한국정밀공학회지
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• 제17권7호
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• pp.124-131
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• 2000

Rapid Prototyping(RP) models are no longer used only for design verification. Currently, parts built utilizing layer manufacturing technology can be employed as functional prototypes and as patterns or tools for different manufacturing processes such as vacuum casting, investment casting, injection molding, precise casting and sand casting. This trend of Rapid Prototyping application meets the requirement of concurrent engineering and its range covers a more spreaded area. The aim of this paper is saving the manufacturing lead time and cost of plastic parts having hollow space shapes used by prototype-car. Using rapid prototype patterns, made by the Selective Laser Sintering(SLS) technique, a new approach of manufacturing resin-based blow mold is discussed. It has a great potential fur making prototype-car parts with the batch size of under 200 parts, in case of rapid modification due to a subsequent design changes in developing stage. So, the process proposed in this research shows reduction of process time and manufacturing cost when compared with the conventional process such as a Zinc Alloy fur Stamping(ZAS) mold.

• 펄프종이기술
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• 제48권3호
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• pp.66-72
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• 2016

The applicability of rice husk fiber as a raw material for eco-friendly pulp mold was evaluated in this study. The higher demand of environmental friendly packaging material resulted in the more interest for the natural fiber based pulp mold. The rice husk which is an abundant agricultural byproduct in Asia could be defiberized by an alkaline digestion process. The changes in the pulp mold making process and the properties of pulp mold by the addition of the rice husk were investigated. The addition of rice husk fiber to the pulp mold made with OCC or UBKP resulted in the increase in drainage at the pulp mold forming process. In case of UBKP pulp mold, the addition of rice husk fiber increased the drying efficiency after pulp mold forming since the structure of pulp mold became more bulkier by the addition of the rice husk fiber. Those results showed the rice husk fiber could be applied to the pulp mold manufacturing as one of the eco-friendly natural fiber resources.

• 한국생산제조학회지
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• 제20권4호
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• pp.478-483
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• 2011

Cast mold has low wear-resistance comparing with other alloyed molds which result in lower production rate and high cost of products. Recently, various weld methods are being applied to increase the wear-resistance of molds and to extend mold life. Among them, nickel alloy weld process increases the hardness irrelevant to its machinability and creates very uniform structures. In addition, it causes better wear-resistance and reduces shrinkage defects. In this paper, we analyze the mold surface cracks welded by nickel alloy and propose the methods to improve the mold surface and its wear-resistance. It has been found that nickel alloy weld does not affect the inside crack of mold but has an influence on the surface crack seriously. Results show that the start and growth of fatigue cracks have been delayed about 3 times and reduced approximately 75%, respectively, and the mold surface cracks are decreased about 5.7 times.

• 한국생산제조학회지
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• 제21권6호
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• pp.998-1002
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• 2012

This paper investigates the behavior of bubbles trapped in the in-mold coating (IMC) process. Silicon oil with different viscosity, 100, 150, 200, 300 and 400cps, was selected instead of the coating materials. To observe the flow front inside, a special mold was designed, where front plate was made of transparent material (acrylate). The overall size of front plate was $150mm{\times}120mm$. Mold gate location can be changed from up to down. Four heaters were used to investigate the effectiveness of temperature. The results show that silicon viscosity, mold gate location and mold temperature play an important role on the appearance of bubbles trapped in IMC process.

• 한국생산제조학회지
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• 제19권4호
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• pp.455-461
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• 2010

Automated magnetic abrasive polishing which can be applied after machining of the mold on a machine tool without unloading is very effective for finishing a complicated injection mold surface. This study aims to realize one step polishing of free form surface with the same machine tool. For this purpose, magnetic flux density according to the change of curvature radii was simulated for selecting polishing conditions and experimental verification was performed with a complicated mold of aluminum alloy. As a result, it was seen by the simulation that the magnetic flux density at a gradual curvature of the mold was higher than at a steep curvature and the higher magnetic flux density produced the better surface roughness in the experimentation. The deviation for the surface roughness of the mold decreased on the whole and the uniform mold surface was obtained after the automated magnetic abrasive polishing.

• Design & Manufacturing
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• 제16권2호
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• pp.60-65
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• 2022

In the pultrusion process for the CFRP (Carbon fiber reinforced plastic) rectangular pipe, the drawing device is eseential which can continuously produces products and draws the carbon fiber tow. In addition, since the degree of cure changes depending on the temperature and the temperature ditribution of the curing mold changes depending on the pultrusion speed, the temperature distribution of the curing mold under certain conditions must be studied before processing. In this study, in the pultrusion process using a closed impregnation method, which has several advantages compared to the general pultrusion process using a open bath impregnation method, the drawing force required to pull the carbon fiber tows and the temperature distribution of the curing mold was analyzed to design the drawing device and the curing mold efficiently.