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전자유압 서보 유량제어밸브의 설계 및 성능에 관한 연구
김수태,김고도 國立 昌原大學校 産業技術硏究所 1999 産技硏論文集 Vol.13 No.-
An experimental and theoretical analysis for the improvement of dynamic characteristics and design of electro-hydraulic flow control servo valve are performed. The theoretical results are compared with the experimental step responses and important design parameters of an electro-hydraulic flow control servo valve are derived by using simulation program. Simulation parameters of nozzle jet coefficient and orifice and spool valve discharge coefficient are obtained by experiment. The results of this study are summarized as follows. 1. Discharge coefficient of small orifices and nozzles (d=0.20∼0.55㎜) are obtained by experiment. The experimental curves show the discharge coefficient change from 0.6 to 0.78. 2. Valve gain depends on R?? value (fixed orifice and nozzle ratio) and theoretical and experimental step response curves show that the valve gain is maximum at R?? = 1 3. Drain orifice in the flapper nozzle return line creates a small back pressure, which improves the performance for the valve. However R?? valve should be larger than 2 because drain orifice decreases valve gain and make valve unstable. 4. The optimum R?? value of the tested valve is 4 in the condition R?? = 1.
최성철,이영락,노영철,이종민,고도경,이정훈,김강윤,김창종,이웅상,허명구,Choi, Sung-Chul,Lee, Yeung-Lak,Noh, Young-Chul,Lee, Jong-Min,Ko, Do-Kyeong,Lee, Jung-Hoon,Kim, Kang-Yoon,Kim, Chang-Jong,Lee, Ung-Sang,Heo, Myeong-Koo 한국광학회 2006 한국광학회지 Vol.17 No.2
펨토초 레이저 펄스를 이용하여 Slide glass 위에 코팅된 Al 박막표면에 나노패턴 구조를 생성하였다. 생성된 나노패턴 구조의 공간적 주기는 레이저 강도와 펄스 수에 의존함을 확인하였고, 레이저 강도와 펄스 수를 미세하게 조절함으로써 Al 샘플 표면에 균일한 나노패턴을 형성 시킬 수 있다. 이와 같은 현상은 레이저 입사빔과 샘플 표면에서 산란되는 빛의 광학적 간섭에서 야기 된다. 또한, Al 박막표면 위에 형성된 산화막이 짧은 주기의 나노패턴을 형성하는데 중요한 역할을 수행하는 것을 확인하였다. Femtosecond laser-induced nano-patterning of an Al surface coated on a slide glass is reported in this paper. It was found that the period of the laser-induced nano-patterning was much dependent on the incident laser power and pulse number. Through finely adjusting the laser power and pulse number, uniform nano-patterns could be formed on the Al surface. It is based on the interference of the incident laser beam with some form of a surface scatted electromagnetic wave. It was also found that an Al oxide layer played an important role in forming the nano-patterning on the Al surface.
한해욱,유난이,전태인,진윤식,박익모,김정회,문기원,한연호,정은아,강철,이영락,고도경,이의수,지영빈,김근주,한경호 한국전자파학회 2008 전자파기술 Vol.19 No.5
최근 테라헤르츠 펄스 기술을 근간으로 하는 테라헤르츠 포토닉스 분야는 새로운 연구 주제로서 전세계적으로 큰 관심을 모으고 있다. 단지 순수과학적 측면에서 뿐만 아니라 상업적 응용 가능성이 높아짐에 따라 많은 선진국에서는 테라헤르츠 포토닉스의 발전을 위해 지대한 노력을 경주하고 있다. 저명한 국제 학술지와 국제 학회에서 테라헤르츠 펄스기술에 대한 논문의 수가 폭발적으로 증가하고 있다는 것은 이러한 사실을 뒷받침하고 있다. 테라헤르츠 응용 기술은 테라헤르츠 펄스 광원과 검출기, 그리고 관련된 수동 소자의 개발이 선행되어야 한다. 따라서 본 논문에서는 테라헤르츠 광전도 안테나, 광정류, 준위상 정합 기반 차주파수 발생, 전광 샘플링, 고속 실시간 측정, 테라헤르츠 전송선, 그리고 각종 도파로 구조와 같은 기초적이면서 핵심적인 소자와 측정 기술에 대하여 간략히 기술하고자 한다. In recent years, the field of ㎔ photonics based on ㎔ pulse technology has gained tremendous, worldwide interest as a new exciting research subject. With a possibility of many commercial applications as well as fundamental scientific achievements in the field, many advanced nations are stepping up their effort in advancing the field of ㎔ photonics. This fact is supported by the observation of the significant increase in the number of papers on ㎔ pulse technology presented in renowned international journals and conferences. The subject that is interesting for the ㎔ application is the development of ㎔ pulse sources and detectors, and other passive devices. In this paper, we present a brief review on some of the key devices and their relavant measurement techniques such as ㎔ photoconductive antennas, optical rectificaton, difference frequency geneneration with quasi-phase matching structures, electrooptic sampling, high speed real time measurements, ㎔ transmission lines, and other various waveguide structures.
윤동원(Dongwon Yun),윤소남(Sonam Yun),박중호(Jungho Park),김고도(Godo Kim),조정현(Junghyun Jo) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
In the field of diesel vehicle, it is important to make fuel atomized and to generate high pressure to reduce the amount of toxin gas and increase the efficieny. So high pressure control valve is widely used in diesel engine and a solenoid valve is of ten used in that kind of valve. In this paper, transient response of solenoid is investigated using Maxwell, commercial FEA code for electromechanical system. Firstly, an experiment about electrical response is performed and then some FE analysis is performed using Maxwell. After that, two results are compared to validate the result of the FEA. Secondly, the system is analyzed considering mechanical parts and the electro-mechanical response is solved.
Evolution Strategy를 이용한 비례 솔레노이드의 형상 최적화
류재섭(J. S. Ryu),윤소남(S. N. Yun),함영복(Y. B. Ham),김고도(G. D. Kim),이현철(H. C. Lee) 한국동력기계공학회 2004 한국동력기계공학회 학술대회 논문집 Vol.- No.-
The constant force characteristics of proportional solenoid actuator in the control region should be independent of the plunger position in order to be used to control the valve position in the fluid flow control system. The stroke-force characteristics of the proportional solenoid actuator is determined by the shape of the control cone. In this paper, steady state characteristics of the solenoid actuator for electro-hydraulic proportional valve determined by the shape of control cone are analyzed using finite element method and it is confirmed that the proportional solenoid actuator has a constant attractive force in the control region independently on the stroke position. And the shape of control cone is optimized using 1+1 evolution strategy to get a constant force. In the optimization algorithm, control cone length, thickness and taper length are used as a design parameter.
함영복(Y. B. Ham),노종호(J. H. Noh),박중호(J. H. Park),김고도(K. D. Kim) 한국동력기계공학회 2004 한국동력기계공학회 학술대회 논문집 Vol.- No.-
As water hydraulics is more and more highlighted in wide applications, many varieties of research on design, materials and manufacturing methods of water hydraulic components have been carried out. Especially, water hydraulic piston pump used to be the subject of study in relation to its relative sliding movement. In these relative sliding parts, the leakage and friction probably took place because of the characteristics of low viscosity and poor lubrication of water. In order to reduce the leakage and friction, the gap can be filled up nearly by using coated-plastic as an anti-wear material on sliding parts. In this paper, before applying the plastic-coated sliding components against the stainless steel to a hydraulic piston pump, the friction and wear test has accomplished with engineering plastic(PEEK) and stainless steel(STS420) specimen. The test machine is a pin-on-disk type, and is able to regulate the load and velocity properly. As a result of the test, tribological characteristics on materials of engineering plastic(PEEK) and stainless steel(STS420) had been verified in the effective and economic respect.