• 한국자동차공학회논문집
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• 제9권4호
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• pp.121-130
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• 2001

For the purpose of optimal control of anti-lock brake systems, precise dynamic characteristics analysis of hydraulic modulator, especially solenoid valve is necessary. However, most of researches so far have dealt with dynamic characteristic analysis of valve itself, and the results have been restrictively applied to the actual ABS modulator, where hydraulic pressure is acting. In this study, mathmatical modeling and experimental analysis were peformed in order to evaluate the valve dynamic characteristics when the hydraulic pressure is applied. High pressure on the master cylinder that affects on the valve dynamic characteristics have been analyzed quantitatively, and performance improvement methods have been suggested through parameter study. Consequently, results of solenoid valve dynamic characteristics analysis derived in the study can be utilized as criteria for the optimal control of anti-lock brake systems.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.117-126
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• 2009

A Common-Rail Direct Injection(CRDI) system for high speed diesel engines was developed to meet reductions of noise and vibration, and emission regulations. In this study, CRDI system analysis model which includes fuel and mechanical sub-systems was developed using commercial software, AMESim in order to predict characteristics for various fuel injection components. Each component which constructs system was modeled and verified by sub-model of AMESim obtained characteristics curves of each components. The parameter sensitivity analysis such as throttle size, injection rate, plunger displacement, supply pressure of fuel injection for system design were carried out by the analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2683-2686
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• 2002

In this paper, it has been investigated that the design and simulation of linear motor for medical appliances. Vacuum pump consists of unified plunger and piston part, coils, inlet valve and outlet valve. Operating principal of vacuum pump show that air is to flow to go inside through the inlet valve, when the magnetic force (16N) is exerted, whereas, air is to flow to go outside through outlet valve, when spring force (14.8N) is exerted. The results of simulation, it was turned out that magnetic force was loaded with 16 Newton, displacement of actuator was about 8mm.

• 대한조선학회지
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• 제25권4호
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• pp.1-6
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• 1988

In this paper two-dimensional breaking waves of plunger type are numerically simulated both on an even bottom and on a sinusoidally-varying bottom within the framework of potential theory. Based on the boundary integral method derived by Vinje and Brevig, fluid particles on the free surface are treated exactly by using semi-Lagrangian time-stepping. Numerical instability, in particular when the wave front becomes vertical, is discussed and the regriding method of nodal points has been found promising. Numerical accuracy is examined in terms of the wave energy and mass conservations. It is also found that the bottom topography affects significantly and the hydrostatic pressure contributes considerably to the nonoscillating force acting on the bottom, when waves are breaking.

• 동력기계공학회지
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• 제4권4호
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• pp.54-58
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• 2000

The complete joining method for dissimilar hot die punch materials and its real-time evaluation method are not available at present. Brazing method has been used for joining them, but it is known that the welded joint by the brazing has the lower bonding efficiency and reliability than the diffusion welding. The friction welding with a diffusion mechanism in bonding was applied in this study. So, this work was carried out to determine the optimal friction welding conditions and to analyze mechanical properties of friction welded joints of hot die punch materials (STD61 for the blade part of hot die punch) to alloy steel (SCM440 for the shank part of hot die punch) such as plunger. In addition, acoustic emission test was carried out during friction welding to evaluate the weld quality.

• 대한기계학회논문집A
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• 제30권10호
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• pp.1202-1208
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• 2006

This paper presents an experimental characteristics of electro-hydraulic proportional pressure control valve. In this study, poppet and valve body which are assembled into the proportional solenoid were designed and manufactured. 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 (or parameters) of the control cone. In this paper, steady state and transient characteristics of the solenoid actuator for electro-hydraulic proportional valve are analyzed using finite element method and it is confirmed that the proportional solenoid actuator has a constant attraction force in the control region independently on the stroke position. The effects of the parameters such as control cone length, thickness and taper length are also discussed.

• 유공압시스템학회논문집
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• 제1권2호
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• pp.15-19
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• 2004

In this study, Design and simulation for low power consumption type pneumatic on-off micro valve was performed. And flow characteristics of the micro valve by stroke change was numerically investigated. As a result, it is shown that magnetic force(6.8N) is exerted enough to move poppet with 0.438mm stroke with 0.01 seconds of response time, and that there is no magnetic force emitted by yoke. Under the condition of poppet stroke smaller than about 0.4mm, dynamic pressure acts to poppet wall up to supply pressure level. But, that is decreasing to 40% when poppet stroke is 0.8mm.

• 한국자동차공학회논문집
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• 제12권6호
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• pp.80-89
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• 2004

In order to confront the increasing air pollution and the tightening emission restrictions, this research developed a diesel engine using DME, the advanced smoke-free alternative fuel. By numerical analysis, flow field, spray, and combustion phenomenon of the DME engine was presented. Using an experimental method, the configuration of the fuel supply system and operation/power performance was tested with the current plunger pump. Most emission performance, especially smoke performance was significantly improved. The possibility of conversion from the current diesel engine into the DME engine was affirmed in this research. However, it was found that the increase of engine RPM and fuel amount need to be properly adjusted through matching the characteristics of fuel and injector for further improvement.

• 유공압시스템학회논문집
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• 제8권1호
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• pp.1-9
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• 2011

The main design factors which effect on operating speed of linear actuator for valve operation are mass of plunger, electromagnetic motive force, inductance, and return spring, and these factors are not independent but related with each other in view point of design and electromagnetic theory. It is impossible to increase the operating speed by only change the value of any one design factor. The change of any one value results in change of any value related it in various design factors. This paper presents a speed increasing method of linear actuator using a solenoid design method by some governing equations which are composed of electromagnetic theory and empirical knowledge and permanent magnets as assistant material, and proved the propriety by experiments.

• 유공압시스템학회논문집
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• 제7권4호
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• pp.44-49
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• 2010

This paper represents solenoid design of control valve for incline angle control in variable compressor. Some theoretical and numerical analysis were performed to analyse solenoid and compared with experimental results. Maxwell program was used for numerical analysis. Through redesigns of housing body, plunger, core, and disk in control valve, the needed force was gotten. Reduction of core groove and housing body air-gap had a large influence on magnetic force. But increasing of disk thickness had little effect on magnetic force. Control valve efficiency could be improved through solenoid redesign.