• 한국정밀공학회지
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• 제21권2호
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• pp.21-26
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• 2004

The formed tool is used to machine the geometrical shape of bearing rubber seal efficiently. The bearing rubber seal has complex geometry for the complicated geometrical shape to prevent leakage of lubricant oil and influx of the dust effectively. Because it is difficult to machine the unique shape exactly by the conventional tool, the formed tool is used in machining a rubber seal die. In this paper, It is performed to investigate machining characteristic of the formed tool； cutting edge wear, cutting force, and surface quality. Also, an efficient precision machining condition is proposed, and the inspection results of rubber seal with CAI are discussed.

• 한국대기환경학회지
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• 제18권5호
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• pp.373-381
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• 2002

Benzene, Ethyl-benzene, Toluene and Xylene (BTEX) can be released to a groundwater in case of the oil leakage from underground storage tank of a gas station. These chemicals are found to contribute to the total inhalation risk from contaminated indoor air. This study presents the assessment of a human exposure to such chemicals released from the groundwater into indoor air. At first, a 2-compartment model is developed to describe the transfer and distribution of the chemicals released from groundwater in a house through showering, washing clothes, and flushing toilets. The model is used to estimate a daily human exposure through inhalation of such BTEX for adults based on two sets of exposure scenarios. Finally, a sensitivity analysis is used to identify important parameters. The results obtained from the study would help to increase the understanding of risk assessment issues associated with the indoor pollution by BTEX released from contaminated groundwater.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.338-341
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• 2007

본 논문에서는 공동주택에서 운전되고 있는 승강기의 노후화 현상에 대한 현장 조사를 실시하였다. 조사대상 승강기는 1990년도부터 시설된 교류제어방식 승강기와 1995년부터 설치된 인버터 승강기이다. 현장 조사 결과 승강기의 주요 노후화 현상은 누유, 마모, 부식 등인 것으로 조사되었다. 또한 승강기가 시설되고 8년이 되는 시점부터 고장 횟수가 크게 증가하는 것으로 분석되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.886-889
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• 2002

This paper describes the characteristic analyses and a new design of the bushing for the pole transformers. The mechanical breakdown of the upper part of the bushing was frequently occurred. This caused the leakage of mineral oil, resulted in the interruption of electric power. Therefore, the bushings were investigated by the material analytical method and Finite Element Method. The analyses were performed by the Induced Coupled Plasma(ICP), X-ray diffraction(XRD), Scanning Electron Microscopy(SEM), and Dielectric Thermal Analyzer(DETA). Also, the Von-Mises stress of the top part of bushing was determined by using ANSYS program. The Von-Mises stress of the newly designed bushing was reduced about 50%. Therefore, if we apply the newly designed bushing, the number of mechanical breakdown may be decreased.

• Tribology and Lubricants
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• 제27권2호
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• pp.65-70
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• 2011

The power servo cylinder for driving accurately turbine stop valve of an atomic power plant is necessary to do turn-over owing to a leakage of oil and a structure problem, especially, it of a power plant be in demand a high quality standard depends entirely on import. There are much problem that the AlBC be to used as a material of piston head in cylinder are caused by wear. Therefore, it is necessary to examine friction characteristics of it. In this study, wear test experiments was carried out with AlBC and SCM440, using reciprocating friction tester of pin on disk. This result was shown that the wear mechanism of AlBC on working condition is adhesive wear and the maximum temperature of infra redray thermal image of frictional surface show over 2 mm from contact surface of pin and disk.

• Corrosion Science and Technology
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• 제6권6호
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• pp.308-310
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• 2007

The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) design of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. We installed the mitigation system at the real field and test of its efficiency in Busan and Seoul, Korea. In this paper, the results of field test, especially, distributed ICCP are described.

• 한국기계가공학회지
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• 제14권3호
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• pp.43-49
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• 2015

This paper describes the design of a forged fitting form to acquire a method of product design measurement by target measurement standards. The pipefitting connects each pipe and combines seals and nipples with the pipes normally. Therefore, the section combined with the fitting pipe was measured by a 3D scanner, and the acquired measurement and the design measurement were obtained after modification of the forged fitting pipe by that standard. Moreover, the accuracy of the model was verified through leakage testing of the oil and verification of the design measurement for accuracy decisions on the design measurement after modification of the product.

• 한국공작기계학회논문집
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• 제11권5호
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• pp.81-87
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• 2002

The existing compressor steel seal used in automotive air-conditioner has the problem of oil leakage and deterioration in shielding performance, due to the abrasion and corrosion of the material. A new type of polymer resin seal studied in this research has the characteristics of high anti-abrasiveness and anti-corrosiveness, which can oversome the defects of the steel seal. In addition, the seal needs lower manufacturing cost and is appropriate to mass production, because it is made by the injection molding method requiring no mechanical processing. The profile generation program for seal mold has been developed using the gradient method, and the molding characteristics of the seal have analyzed through the flow analysis and the warpage analysis. The program has been verified by comparing the analysis results with the measured data of the test product. The research might be said to provide the basic method to produce the polymer resin seals with various types and dimensions.

• 대한기계학회논문집B
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• 제28권2호
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• pp.154-159
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• 2004

A new microflow rate controller for medical injection was developed and evaluated. The flow rate was controlled by changing the friction depth as well as the friction length of the micro-channel. A precise micro-fabrication of the micro-channel was requested for an accurate flow control. The friction depth was inversely proportional to the friction length, which gives a linear flow control to the channel length. The channel groove was fabricated with a plastic material. A rubber containing silicone oil was covered over the groove, which satisfies both lubrication and leakage prevention. The flow controller was validated by performing the numerical simulation and experiment. A good agreement was shown between computation and experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1807-1810
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• 2003

The formed tool is used to machine the unique shape of rubber seal for geometrical shaping and reduction of cutting time. The bearing rubber seal produced by hot press forming has complex geometry for the complex geometrical shape to prevent leakage of lubricant oil and influx of the dust effectively. Because it is difficult to machine the unique shape exactly by the conventional tool, the formed tool is used in machining mold of the seal. In this paper, It is performed for selection of the formed tool to investigate cutting edge wear, cutting force, and surface quality. Also, an efficient high precision machining is proposed on the experiment data.