• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2280-2282
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• 2001

EMV(electromagnetic valve) 시스템은 자동차에서 기계식 캠을 사용하지 않고 전자기력을 이용하여 흡·배기 밸브를 작동시키고 타이밍을 조절하기 위한 것이다. 본 논문에서는 EMV 시스템을 위한 전자기와 기계적 모델을 사용하여 그에 대한 동역학 모델을 유도하였다. EMV 시스템의 최대 동작주파수가 가솔린 엔진의 최대 회전수 6000rpm에 대응한 valve의 주파수가 50Hz 되기 위한 제어기를 설계하였고, 실험을 통하여 문제점들을 파악하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.15-20
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• 2017

The main purpose of the ball valve ball is to be moved by the rotation of the stem when fully open or completely closed. In this study the heat of the initial model, which used a structure interaction analysis technique, tried to examine the structural safety of the high temperature for the ball valve. In the initial model the stress of the exiting sheet was more than the yield strength. We selected two design shapes with variables of length and thickness for the optimization of the sheet. The Kriging interpolation method was applied to a meta-model-based optimization technique. As a result, it was possible to find a thickness and length for the sheet within the yield strength. This was done by measuring the value of the capacity coefficient of the valve and evaluating the performance of the ball valve.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.76-81
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• 2016

At negative-g condition, a float-type valve can open the passage of fuel in order to it flows continuously through a pressurized fuel tank system. Since specialized test conditions and high-cost supports are required, it is truly difficult to test the valve in a real high-speed test. Therefore, this paper contains performance analysis of a float-type fuel supply valve through flight tests conducting roll and negative-g maneuvers.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.75-78
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• 2002

In this paper, flow on the rear region of a butterfly valve was analysed by using numerical and experimental methods. The butterfly-valve disk angle is changed as 0-60 degree and the uniform flow velocity was fixed In this experiment. It was shown that the numerical results are similar to the experimental results. General discussions are given to the flow-pattern change upon the disk angle of the valve.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.27-34
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• 1997

The effects of the intake and exhaust valve timing to improve the engine performance in a spark ignition 3-cylinder LPG engine with a closed loop fuel supply system were studied. The engine torque and power have been measured using the 75kW EC-dynamometer while adjusting the optimal fuel consumption ratio with a solen- oid driver. As the results from this experiment, when intake valve opening is $12^{\circ}$ BTDC, intake valve closing is $36^{\circ}$ ABDC, exhaust valve opening is $12^{\circ}$ ATDC, and exhaust valve closing is $36^{\circ}$ BBDC respectively, the best torque characteristics in low and high speeds for a gives engine were obtained. And also we could find that the torque characteristics in low speeds were affected by the timing of exhaust valve open. An increased valve overlap by the EVC delay was ineffectual to the torque characte- ristics improvement in high speeds.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.110-115
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• 2015

In this paper it is proposed to solve the problem of particulate matter reducing apparatus of the current DPF. One exhaust gas passage 2-way controlled to purify the exhaust gas generated during combustion efficiently. Through the control of the rotary valve within a single device, it is possible to prevent the exhaust pressure increases due to particulate matter accumulate inside the developing DPF. Develop DPF device capable of inducing a high efficiency of the output in order to improve the problem of reducing the engine output and fuel efficiency.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.4 s.27
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• pp.267-272
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• 2006

Butterfly valves have been used for shut-off and throttling-control application in many industrial fields. Recently, they are frequently used for cooling water, oil system and ballast piping system of many larger vessels. They are especially suited for flow throttling control of heat exchangers in engine room. Measurement by the PIV(Particle Image Velocimetry) was conducted to investigate the flow characteristics of butterfly valve inserted within circular pipe. Flow behaviors such as instantaneous and time-mean velocity vectors are investigated. Furthermore, to reveal systematic performance of the butterfly valve, wall pressure was measured at 6 points along the pipe by digital manometer. As the valve position moves to the closed side, flow separation increases and persists its tendency downstream until smoothly uniform flow developed. The pressure loss is found to be about zero for the disk open angles less than 45 degrees, but is substantially increased for those larger than 60 degrees.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.5
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• pp.701-706
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• 2007

Recently, a number of researches about linear magnetorheological(MR) damper using valve-mode characteristics of MR fluid have sufficiently undertaken, but researches about rotary MR damper using shear-mode characteristics of MR fluid are not enough. In this paper, we performed vibration control of shear-mode MR damper for unlimited rotating actuator of mobile robot. Also fuzzy logic based vibration control for shear-mode MR damper is suggested. The parameters, like scaling factor of input/output and center of the triangular membership functions associated with the different linguistic variables, are tuned by genetic algorithm. Simulation results demonstrate the effectiveness of the fuzzy-skyhook controller for vibration control of shear-mode MR damper under impact force.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.582-590
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• 2019

As Korea's low fertility and aging progress, Korea is facing a social change such as an increase of one generation by entering an aging society that has raised 14% of the population. An effective way to prevent a gas fire accident caused by an increase in one generation in an aging society is to install a control valve to forcibly shut off the gas after a set time. In this study, we developed a valve that can be opened and closed by rotating the valve left and right by transmitting power to the worm gear and the helical gear by using a motor by pressing the switch. It is easy to assemble and inspect by developing a dedicated valve that is easy to attach and detach. It was developed to enhance competitiveness by reducing cost by reducing the number of parts and product size. In addition, through endurance test, it was developed to be used for more than 9 years by repeating ON / OFF once every 12 seconds so that it can operate stably for 10,000 times for 34 hours. The instrument and PCB were designed using solid works and Altium Designer tools. Firmware development was developed in IAR Embedded Workbench environment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.712-721
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• 2015

Pulse Detonation Engine (PDE) has been considered as a future propulsion system for broad range of operation and higher thermal efficiency. Various subsystem technologies have been studied for more than decade to improve the performance of the potential system. New valve systems has been developed for the stable operation at high frequency including inflow-driven valve, rotary valve and valveless system. To foster the detonation initiation with a little ignition energy, plasma ignition method and DDT (deflagration to detonation transition) acceleration method such as swept ramp mechanism have been studied. Fluidic nozzle system and other nozzle system are the ongoing research topics to maximize the propulsion performance of the PDE. Present paper introduces the state of the art of PDE subsystem technologies developed in recent years.