• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.951-953
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• 2011

본 논문은 현장에서 사용하고 있는 밸브 수압측정기를 3차원 자동설계 프로그램인 CATIA를 활용하여 설계하였다. 또한 3차원 유한요소 코드인 ANSYS를 활용하여 설계된 수압측정기에 대하여 유한요소 해석을 수행하여 내부압력에 따른 유체의 흐름을 구하였다. 본 해석결과를 활용하여 새로운 수압측정기를 개발함으로서 밸브 점검 시 시간을 단축하고, 사고를 방지하여 안전성을 향상시킨다.

• 기계와재료
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• v.21 no.3
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• pp.42-51
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• 2009

원자력/화력 발전소에서 사용중인 터빈출력제어장치(turbine power control device)는 유압 서보액추에이터(hydraulic servo actuator)로 구동하는 특수 스팀 밸브(steam valve)로서 터빈의 속도를 제어하고 스팀을 차단하는 기능이 있다. 대형 발전기(500~1000Mw)를 구동하여 양질의 전기를 생산하기 위해서는 발전기에 연결된 고압 및 저압터빈에 최적량의 스팀을 공급하여야 하고, 고속(화력 3600 rpm, 원자력 1800 rpm)으로 회전하는 터빈이나 스팀계통에 이상이 발생할 경우 터빈의 과속(over speed) 방지를 위하여, 즉시 터빈으로 공급되는 스팀을 차단하여 터빈을 보호해야 한다. 따라서 터빈의 속도제어와 계통의 스팀 량을 감시하여 차단하는 발전소의 특수 밸브의 신뢰성확보기술이 요구된다. 특히 원자력발전소의 경우 핵연료교환주기(약 24개월)에 밸브들을 정비 또는 교체하고 있어 이때마다 시스템과 매칭(튜닝)기술이 요구되었다. 본 연구에서는 전량 수입에 의존했던 원자력/화력 발전소의 특수 밸브인 터빈출력제어장치의 국산화 개발과 신뢰성확보기술 효과에 대하여 논하였다.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.174.5-174
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• 2001

In this paper, mathematical modeling and dynamic characteristics analysis of a continuously variable damper used for semi-active suspension systems are investigated. After analyzing the geometry of a typical continuously variable damper, models for various components including piston, orifices, spring, and valves are proposed and the flow equations during expansion and compression strokes are derived. To verify the mathematical models developed, the dynamic characteristics of the models are simulated using MATLAB/SIMULINK and are compared with experimental results. It was confirmed that the developed models represent well the actual damper and can be used for control system design.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.111.6-111
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• 2001

A seat suspension system with a controlled MR(Magneto Rheological) fluid damper is introduced to improve the ride quality and prevent the health risk of a driver compared to conventional seats. The system locates between a seat cushion and base, and is composed of a spring, MR fluid damper and controller. The MR fluid damper designed in valve mode is capable of producing a wide range of damping force according to applied currents. In experiments, a person was sitting on the controlled seat excited by a hydraulic system. The skyhook control, continuous skyhook control and relative displacement control were applied and the continuous skyhook control improved the vibration suppression by 36.6%.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.84-90
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• 2001

The electro-reheoligical(ER) effect refers to the abrupt change in viscosity in certain suspensions on application of an electric field. This paper presents experimental results on material properties of an ER fluids subjected to electrical fatigues. As a first step, two types of EF fluids are made of arabic gum and methyl cellulose(MC) choosing 25% of parti-cle weight-concentration. Following the construction of test mechanism for electrical durability of ER fluid, the dynamic yield shear stress and current density of the ER fluids are experimentally distilled as a function of electric field. The yield shear stress of operated ER fluids are distilled and compared with those of unused ER fluids.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.265-268
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• 1997

In the recent day, fatigue life prediction techniques play a major role in the design of components in the ground vehicle industry. Full scale durability testing in the laboratory is an essential of any fatigue life evaluation of components or structures of the automotwe vehicle. Component testing is part~cularly important in today's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, multi-axial road simulator is used to carry out the fatigue test and the vibration test. In this paper, the algorithm and software to realize the real road profile are developed. The validity of the software are verified by applying the belgian road, the city road, the highway, and the gravel road. The results of the above experiment show that the real road profiles are realized well after loth iteration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.591-594
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• 2000

In the recent day, fatigue life prediction techniques play a major role in the design of components in the ground vehicle industry. Full scale durability testing in the laboratory is an essential of any fatigue life evaluation of components or structure of the automotive vehicle. Component testing is particulary important in today's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, 3-axis durability testing device is used to carry out the fatigue test. In this paper, The operation software for simultaneously driving 3-axis vibration testing device is developed and the displacement of the 3-axis actuator is separately calibrated by LDT Moreover, the input and output data are displayed in windows of PC controller with real time.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.10
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• pp.861-866
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• 2002

A seat suspension system with a controlled MR(Magneto Rheological) fluid damper is introduced to improve the ride quality and prevent the health risk of a driver compared to fixed seats. The system is located between a seat cushion and the base, and is composed of a spring, MR fluid damper and controller. The MR fluid damper designed in valve mode is capable of producing a wide range of damping force according to applied currents. In experiments, a person was sitting on the controlled seat excited by a hydraulic system The skyhook control, continuous skyhook control and relative displacement control were applied and the continuous skyhook control improved the vibration suppression by 36.6%.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.435-440
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• 2000

In this study, we aims to develop the machining technology for the ultra precision surface and profile accuracy. For this purpose, we construct the electrolytic in process grinding system (ELID grinding) and apply to the cylindrical and internal grinding. Through the various machining experiments such as SCM steel., ceramics, tungsten carbide etc., we have obtained nanometer surface roughness. And we have applied this mirror grinding technique to hydraulic manual valve and mold core of mini disk optical pick-up base. For the development of fine mechanical part machining technology, e have made multi fiber optical connector using fine grinding technology. And constructed micro drilling system with process monitoring system which is possible to drill 50${\mu}{\textrm}{m}$ diameter hole.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.5
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• pp.638-646
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• 1985

Water hammering in nuclear or thermal power plant condenser cooling water systems in mathematically modeled and numerically analyzed based on the method of characteristics. Effects of variations of the discharge valve operating condition and the system geometry on the hydraulic transients are investigated for the cases when all or one of four pumps are tripped accidently due to loss of offisite power. Effects of ocean waves and tides on the steady-state and the transient operations are also studied. Water column separation in taken into account whenever necessary by means of a simplified physical model.