• 대한기계학회논문집B
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• 제36권10호
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• pp.971-977
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• 2012

고압 인젝터의 성능은 디젤 연소엔진의 동력, 배출물, 연료소모와 직접적인 관계가 있다. 본 논문에서는 솔레노이드 코일과 피에조 세라믹으로 구동되는 커먼레일 디젤 분사용 인젝터의 응답 특성을 AMESim 코드를 사용하여 상대 비교 연구를 수행하였다. 따라서 연료압력, 분공경을 주요 해석변수로 설정하였다. 본 연구를 수행한 결과, 솔레노이드 구동 인젝터에 비해 피에조 구동 인젝터가 상대적으로 더 빠른 응답성과 더 높은 제어성을 가짐을 알 수 있었으며, 특히 다단분사 적용시, 이런 결과가 매우 효과적임을 확인할 수 있었다.

• 한국분무공학회지
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• 제15권2호
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• pp.67-73
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• 2010

The capability of pilot injection with small fuel quantity at all engine operating conditions is one of the main feature of the common rail direct injection system. The purpose of the pilot injection is to lower the engine noise and to reduce the NOx emissions. This study describes the pilot spray structure characteristics of the common-rail diesel injectors with different electric driving characteristics, including solenoid-driven and piezo-driven type. Namely three common-rail injectors with different electric current wave were investigated in this study. The pilot spray characteristics such as spray speed, spray tip penetration, and spray angle were obtained by spray images, which is measured by the back diffusion light illumination method with optical system for high-speed temporal photography. As this research results, it was found that pilot injection of common-rail system was effected by rate of injection with different electrical characteristic for injector driving.

• 한국분무공학회지
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• 제15권1호
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• pp.25-30
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• 2010

The capability of pilot injection with small fuel quantity at all engine operating conditions is one of the main feature of the common rail direct injection system. The purpose of the pilot injection is to lower the engine noise and to reduce the NOx emissions. This study describes the pilot spray structure characteristics of the common-rail diesel injectors with different electric driving characteristics, including solenoid-driven and piezo-driven type. Namely three common-rail injectors with different electric current wave were investigated in this study. The pilot spray characteristics such as spray speed, spray tip penetration, and spray angle were obtained by spray images, which is measured by the back diffusion light illumination method with optical system for high-speed temporal photography. As this research results, it was found that pilot injection of common-rail system was effected by rate of injection with different electrical characteristic for driving the injector.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.33-34
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• 2006

In this study, a prototype piezo-driven Injector. as a new method driven by piezoelectric energy, has been designed and fabricated based on the concept of inverse piezo-electric effect to overcome the major drawbacks of conventional solenoid-driven injector with a fixed and slow control of injection rate. The effects of an electric control between the solenoid valve and piezo-ceramic stack for injector needle's driving on the dynamic characteristics were usually investigated. We found that this piezo-electric actuator has the main advantage to drastically reducing the time of injector nozzle opening, as well to exert higher force output levels.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.174-185
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• 1997

The performance of the solenoid actuated hydrogen injector and the capacitive peak-hold type driving circuit was predicted through the modeling of the injector and the driving circuit the modeling was composed of the driving circuit, the solenoid, the moving parts of the injector, and the hydrogen injection system. The performance of the injector through the modeling was compared with the results of the solenoid and injector rig tests, and those were consistent with each other. Through the prediction of the injector performance, the effects of the components such as electrical resistor, capacitor, and injector spring are easily known to the injector performance required.

• 한국자동차공학회논문집
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• 제3권6호
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• pp.134-144
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• 1995

The solenoid actuated hydrogen injector and the capacitive peak-hold type driving circuit were designed and made, and the hydrogen supply system for in-cylinder injection was constructed with these. The performance of the injector was investigated through measuring the pintle lift profiles and the injection quantities, and the performance of the hydrogen supply system was confirmed through the experiments at the single cylinder engine. The injection quantity increased linearly as the duration of driving signal increased. At the single cylinder engine, the hydrogen injector was operated stably. The hydrogen flow rate of the injector with the peak-hold type driving circuit could be controlled precisely at high engine speed or low load condition only with the variation of signal duration.

• 한국분무공학회지
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• 제19권1호
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• pp.9-14
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• 2014

Performance of DI diesel engine with high-pressure fuel injection equipment is directly related to its emission characteristics and fuel consumption. So, the electro-hydraulic injector for the common-rail injection system should be designed to meet the precise high fuel delivery control capability. Currently, most high pressure injector in use has a needle driven by the solenoid coil energy or the piezo actuator controlled by charge-discharge of output pulse current. In this study, macroscopic spray approaching method was applied under constant volume chamber to research the performance of three different injectors : solenoid, indirect-acting piezo and direct-acting piezo type for CR direct-injection. LED back illumination for Mie scattering was applied on the liquid spray visible of direct-acting piezo injector, including hydraulic-servo type solenoid and piezo-driven injectors. As main results, we found that a direct-acting piezo injector had better a spray tip penetration than hydraulic-servo injectors in spray visualization.

• 한국분무공학회지
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• 제24권3호
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• pp.114-121
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• 2019

The effect of injector driving current pattern on fuel injection rate of solenoid diesel common rail injector was studied by computer simulation. The time resolved fuel injection rate and injected quantity per stroke of a common rail injector driven with the five current patterns were computer simulated. The fuel injection rate and injected quantity per stroke according to the rail pressure and fuel injection period were also computer simulated. When the common rail injector was driven with the five driving current patterns of peak & hold, there was no difference in the fuel injection rate in the peak section regardless of all the current patterns of the five cases. On the other hand, the magnitude of the hold current value influenced the injection rate and injected quantity per stroke. That is, in the current pattern of three cases where the hold current value is equal to or more than a constant value of the peak current value, the fuel injection rates for the given common rail rail pressure and injection period are same one another. On the other hand, the current pattern of the two cases, in which the hold current value is smaller than a certain value, there is a large fluctuation in the fuel injection rate.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.17-24
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• 2006

This study was performed to figure out spray behavior and fuel atomization characteristics of a piezo-driven injector and a solenoid-driven injector in the common-rail injection system under the same design parameters and test conditions. The process of spray injection was visualized by using the spray visualization system composed of a Nd:YAG laser and an ICCD camera. The atomization characteristics were investigated in terms of axial mean velocity, Sauter mean diameter(SMD) and droplet distributions obtained from a phase Doppler particle analyzer system. Compared with solenoid-driven injector, the piezo-driven injector has short injection delay and reaches quickly to the maximum injection value. Spray tip penetration shows some difference, however, spray angle of piezo-driven injector is wider than that of solenoid-driven injector. Sauter mean diameter of piezo-driven type injector is smaller than that of solenoid-driven type.

• Journal of Advanced Marine Engineering and Technology
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• 제30권3호
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• pp.351-358
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• 2006

The capability of high pressure injection with small fuel quantify at all engine operating conditions is one of the main feature in common rail fuel injection system, which is used in small and light-duty Diesel engine. The key parameter for the better atomized fuel sprays and multiple injections of this common rail fuel injection control, that can be freely selected irrespective of the engine speed and load is the mechanism controlling the needle energizing and movement in high pressure Diesel injector. In the electro-hydraulic injector, the injection nozzle is being opened and closed by movement of the injector's needle which is balanced by pressure between the nozzle seat and the needle control chamber. This study describes the macroscopic spray structure characteristics of the common rail Diesel injectors with different electric driving method i.e. the solenoid-driven and piezo-driven type. The macroscopic spray characteristics such as spray tip speed. spray tip penetration and spray cone angle were investigated by the high speed spray, which is measured by the back diffusion light illumination method with optical system for the high speed temporal photography in a constant volume chamber pressurized by nitrogen gas. As the results, the prototype piezo-driven injector system was designed and fabricated for the first time in domestic case and the effect of injector's needle response driven by different drive type was compared between the solenoid and piezo-driven injector It was found therefore. that the piezo-driven injector showed faster needle response and had better needle control capability by altering the electric input value than the solenoid-driven injector.