• 반도체디스플레이기술학회지
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• 제17권3호
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• pp.53-58
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• 2018

The modern industry requires the precision machining as well as the high productivity. The machine tool structure should be evaluated in aspects such as durability, static stability, precision rate and the dynamic stability which is one of the most critical characteristics in determining the magnitude of vibrations. In this study, the dynamic properties of a pipe cutting machine were investigated to analyze the structural vibrations of the machine, and further to improve the structural stability and precision machining. Frequency response test and computer simulation have been utilized for the analysis and the design alterations. And the result shows that proposed design alterations can reduce the vibrations of the machine substantially.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.21-29
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• 2013

For the purpose of supporting Curved Blocks, pipe welding is commonly used on Curved panel. Typically, when it comes to attaching supporting pipe on heavy incurvated surface, it makes much loss in the process of design, cutting, welding. This paper gives proper methods to collecting problems and Core conflicts surrounding Support Pipe by using of TOC (Theory Of Constraints). Therefore drawing two solutions, pipe development program and NC generating from pipe development Data for Plate Cutting machine. It describes a process of erasing loss surrounding Support Pipe with "TOC Thinking process" and development of two programs in this paper.

• 한국건설순환자원학회논문집
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• 제6권1호
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• pp.72-77
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• 2018

본 연구에서는 하수관의 접합부 돌출부 절삭용 로봇을 개발하고, 이의 성능평가를 수행하였다. 하수관로 절삭 성능평가를 위해 주하수관의 재질 및 직경, 가지관의 재질을 실험변수로 설정하였다. 주하수관의 재질은 콘크리트 흄관과 PE관을 사용하고, 직경은 300 및 500mm를 적용하였다. 가지관의 재질은 PE 및 PVC로 설정하고, 직경은 100mm로 설정하였다. 절삭로봇을 개발된 이용하여 절삭성능 실험을 수행하였다. 절삭실험 후의 가지관의 잔여 돌출 길이는 5mm 이하로서 목표 절삭 잔여 길이를 모두 만족하고 있다. 따라서 개발된 하수관로 절삭로봇을 이용하여 하수관 접합부 돌출관을 효과적으로 절삭할 수 있다.

• Nuclear Engineering and Technology
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• 제50권7호
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• pp.1088-1098
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• 2018

Kori unit #1, which is the first commercial nuclear power plant in Korea, was permanently shutdown in June 2017, and it is about to be decommissioned. Currently in Korea, researches on the decommissioning technology are actively conducted, but there are few researches on workers internal exposure to radioactive aerosol that is generated in the process of decommissioning nuclear power plants. As a result, the over-exposure of decommissioning workers is feared, and the optimal working time needs to be revised in consideration of radioactive aerosol. This study investigated the annual exposure limits of various countries, which can be used as an indicator in evaluating workers' internal exposure to radioactive aerosol during pipe cutting in the process of decommissioning nuclear power plants, and the growth and dynamics of aerosol. Also, to evaluate it, the authors compared/analyzed the cases of aerosol generated when activated pipes are cut in the process of nuclear power plants and the codes for evaluating internal exposure. The evaluation codes and analyzed data conform to ALARA, and they are believed to be used as an important indicator in deriving an optimal working time that does not excess the annual exposure limit.

• Tribology and Lubricants
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• 제22권4호
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• pp.225-229
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• 2006

The issue with the drainpipe now a day is that they are laid underground. Causing us to perform additional work to repair, such as digging up the ground and peeling off the insulator that surrounds the pipe. And such series works are difficult that concession appears from government and municipal office. However, if we can save time and money. Performance of piping robot that we are studied in existing session through fixing unit and improvement of cutting bit shorten and wished to heighten work efficiency. And we are trying to develop a unit that can cut up the projecting parts which connects with the interior part of the drainpipes.

• 한국건설관리학회논문집
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• 제19권6호
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• pp.115-123
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• 2018

강관말뚝 두부정리 작업은 안전성, 품질의 균일성, 작업 생산성 측면에서 개선이 필요하며, 이를 개선하기 위한 자동화 및 기계화 등 대안마련이 시급한 실정이다. 본 연구의 목적은 상기 문제점을 개선할 수 있는 굴삭기 기반 강관말뚝 두부정리 및 절단 부위 핸들링 로봇의 풀스케일 프로토타입을 개발하는 것이다. 이를 위해 본 연구에서는 1)선행기술 분석 및 현장 전문가 설문조사, 2)AHP 분석을 활용한 핵심 요소기술 선정, 3)상세설계 도출, 4)구조적 안정성 분석, 5)풀스케일 프로토타입 개발을 수행하였다. 핵심 요소기술 선정 결과, 레이저 레벨기 및 수광기(94.46점), 강관말뚝 절단 기능에서는 플라즈마 절단(96.72점), 강관말뚝 인양 및 운반 기능에서는 회전형 그래플(93.45점)이 선정되었으며, 구조적 안정성 분석 결과, 구조적으로 가장 취약할 것으로 판단되는 3개 부재(그립부, 실린더 피벗 브라켓, 그립부 베이스)에서 최소 2배 이상의 구조적 안정성을 확보할 수 있는 것으로 분석되었다. 최종적으로 개발된 풀스케일 프로토타입은 센싱부 정확도 3.39mm, 절단부 절단 속도 1분 59초로 강관말뚝 두부정리 작업의 자동화를 위한 충분한 성능을 확보한 것으로 분석되었다. 본 연구를 통해 개발된 굴삭기 기반 강관말뚝 두부정리 및 절단 부위 핸들링 로봇은 현업에서의 요구가 충분히 반영되고 기술적 타당성이 확보되었으므로 그 실용화 가능성이 높을 것으로 기대된다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.365-370
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• 1999

SKD11 is one of the most difficult workpiece for machining, so it is necessary to evaluate the machining characteristics of SKD11. The workpiece was made to be the pipe form and heat-treated to HRC45. In this paper, the orthogonal cutting experiment of this material was carried out with TiAlN coated WC cutting tool of 4 kinds of rake angle. After cutting experiment, cutting characteristics of SKD11 were investigated according to variation of cutting speed, feedrate and rake angle.

• 동력기계공학회지
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• 제5권3호
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• pp.73-79
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• 2001

The purpose of this investigation is experimentally to clarify the machinability and tool wear of STS 304 steel pipe material for piping. In order to determine the effects of cutting parameters and tool wear on thrust, torque, AE RMS, drilling is conducted on CNC milling machine. In this experiment, it is measured that thrust, torque, tool wear length, tool wear area and AE RMS during drilling using Hss tool. It has been found that a) During the drilling, the thrust and the torque of the STS 304 pipe are received more the effect of the feed than the spindle speed and the thrust increase with the increase of feed, b) The value of the AE RMS is been larger the effect of the cutting speed than the feed rate, and the value of the AE RMS increase with the increase of spindle speed, c) It has been found that the suitable feed in feed condition of 0.03, 0.05, 0.1, 0.15mm/rev is below 0.05mm/rev, d) The value of the AE RMS was shown a characteristic of the jump value during it was a sudden inrcrease of the tool wear. The increased character of the AE RMS value can be known an effective factor of the tool wear detection, and e) It can be quantitatively evaluated the condition of the tool according to calculate a area of the drill wear image which is obtained by a vision system.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.488-493
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• 2003

This paper presents new skill in tube-mill processing getting the increase in production efficiency and quality in response to the recent request of high grade pipe. In this study, researchers developed the method to improve the precision of pipe and tool life in tube-mill processing. Optimum tool shape is devised by analyzing various simulation and mechanism in cutting process. In order to verify the confidence of the proposed machining technology, it is applied to the real processing machinery in the field.

• 한국환경과학회지
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• 제15권1호
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• pp.95-100
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• 2006

Heat transfer and flow characteristics in a pipe in which the rotating cutting tool for boring a underground pipe without digging were considered in this study. The amount of heat generation due to the friction between the rotating cutter and pipe wall, mixing (low of air and water injected to cool down are the two important factors to design the boring machine Computational fluid dynamics analysis using the Eulerian mixture model and the standard $\kappa-\varepsilon$ turbulence model was used to analyze the complex phenomena in a pipe during the process. Results show that pipe wall temperature decreased with increasing the cooling water inlet velocity. it is also shown that pipe wail temperature was lowered when the cutter rotation speed was increased until 600 rpm. There was no further cooling effect over 600 rpm.