배기 다기관 형상 변경에 따른 배기계에서의 배기 압력 특성에 관한 연구

심국상,최민호,김세웅 금오공과대학교 산업기술개발연구원 2000 産業技術開發硏究 Vol.16 No.-

Exhaust pressure characteristics was described by change of exhaust manifold configurations in the exhaust system. Exhaust manifolds for analysis of exhaust pressure characteristics in this experiments were made and were single, double and conventional type of manifold. The pressure characteristics in the exhaust system were compared and analyzed according to exhaust manifold configurations, measuring positions, engine revolutions and loads. The results show that the peak pressure in exhaust system was decreased as the number of accessories in the exhaust manifold increased and the measuring position of sensor estranged from exhaust valve. And the accumulation of exhaust gas occurred in exhaust manifold was decreased by formulation of pulsating pressure wave than formulation of high pressure wave.

평균 배기 압력 구배 지수를 이용한 실화 검출 방법

심국상,최민호,김세웅 金烏工科大學校 2000 論文集 Vol.21 No.-

This paper proposes a method to detect the misfired cylinder using a new misfire detection index. The new method of misfired cylinder is a comparison of pressure gradient during the blowdown period of exhaust stroke. If a misfire occurs, the engine will be lost some power and consumes the more fuel and the torque will be unsteady. Most of all, the misfire affects a bad influence of the 3-way catalyst and emits unburned hydrocarbon in the air. To prevent these unusual phenomena and eliminate the factor of the environmental pollution, it is important to detect the misfired cylinder. To do the experiment, set up the assist device on the conventional exhaust manifold. This assist device is not deformed for conventional exhaust manifold and installed in the end of the exhaust manifold. Experimental results showed that the method using the mean gradient pressure index is proven to be effective in the detection of misfired cylinder on gasoline engine regardless loads and revolutions of the engine

배기관 내 압력 변동 분석에 의한 가솔린 기관의 실화 검출

심국상(K.S.Sim),복중혁(J.H.Bok),김세웅(S.W.Kim) 한국자동차공학회 1998 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1998 No.5_1

This paper describes the method for detection of the misfired cylinder by analysis of the variation of pressure occurred in exhaust manifold on an MPI gasoline engine.<br/> Misfired cylinder or cylinders cause a loss of power and an increase of fuel consumption and exhaust emission and vibration is caused by unsteady torque.<br/> Therefore early detection and correction of misfired cylinder or cylinders play a very important role in the proper performance and the exhaust emission.<br/> The method is a comparison of integration pressure index during the period of a blowdown in the displacement period. Experimental results showed that the method using the variation of pressure in the exhaust manifold is proven to be effective in the detection of single cylinder or multiple cylinders misfire on the gasoline engine regardless of the engine revolutions.<br/> In addition, this method, using the variation of pressure in the exhaust manifold is a very easy and accuracy method compared with other methods and is a not a need of additional reconstruction of engine.<br/>

배기계 압력 변동을 이용한 가솔린 기관의 실화 검출-단수 실린더 실화-

심국상(K.S.Sim),복중혁(J.H.Bok),김세웅(S.W.Kim) 한국자동차공학회 1997 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1997 No.11_1

This paper describes the method for detection of the misfired cylinder using the pressure fluctuations occured on exhaust system on an MPL gasoline engine.<br/> If misfire is occured in the cylinder of the gasoline engine, the power of engine gets lost, the fuel consumption and the exhaust emission are increase and the vibration is caused by unsteady torque. Therefore early detection and correction of misfire play a very important role in the proper performance and the exhaust emission. This paper suggests method of misfire detection which affect engine performance.<br/> The method is a comparison of average pressure index during the displacement period. Experimental results showed that the method using the pressure fluctuations in the exhaust system is proven to be effective in the detection of misfire on gasoline engine regardless loads and revolutions of the engine. In addition, this method, using the pressure fluctuations in exhaust system is easy compare to other method and is not a need of additional reconstruction of engine.<br/>

배기계 압력 변동을 이용한 가솔린 기관의 실화 검출 - 단수실린더 실화 -

심국상(K. S. Sim),복중혁(J. H. Bok),김세웅(S. W. Kim) 한국자동차공학회 1998 한국 자동차공학회논문집 Vol.6 No.6

가솔린 기관의 배기계 압력 특성 분석

김세웅,복중혁,심국상 金烏工科大學校 1997 論文集 Vol.18 No.-

This paper describes the characteristics of pressure in the exhaust system. Exhaust system of gasoline engine consists of an exhaust manifold, a primary and a secondary muffler and a 3-way catalyst. And these compositions are tested in the before and behind of each composition. The pressure waves of burnt gas generated in the 4 stroke and 4 cylinder engine are formatted tatal eight pressure waves during the one cycle. The first pressure wave is generated by blowdown and the second pressure wave is generated by burnt gas and velocity of ascending piston. These pressure waves depend on pressure of burnt gas and the second pressure wave is bigger than the first pressure wave as the increased of load. If pressure waves in the exhaust system are analyzed, the cylinder of normal or abnormal combustion is classified and the misfire cylinder could be detected.

배기관 내 압력 변동 분석에 의한 가솔린 기관의 실화 검출

심국상(Kooksang Sim),복중혁(Junghyock Bok),김세웅(Sewoong Kim) 한국자동차공학회 1999 한국 자동차공학회논문집 Vol.7 No.5

각속도 변동 지수와 크랭크각 지수를 이용한 가솔린 기관의 실화 검출

이근봉,김세웅,심국상 國立金烏工科大學校附設生産技術硏究所 1997 産業技術開發硏究 Vol.13 No.-

This paper introduces a diagnostic technique for the detection of faulty cylinders of internal combustion engines, using the indexes of the angular velocity variation and the crankshaft angle. Many types of faults may occur during the operation of internal combustion engines. These include low compression pressure, failure of ignition or combustion of malfunction of the fuel system. Early detection and correction of engine faults restore proper performance, improve engine efficiency and reduce costs. From the idea that the fluctuation of crankshaft speed contains the information of combustion phenomena, angular velocity variation is measured, with an interval timer and a magneric pick-up sensor, by timing the flywheel gear teeth as they pass the sensor. The angular velocity and angular acceleration are determined by cylinder pressure, load, inertia, and friction of the engine. The angular acceleration patterns, as well as the velocity patterns, are varied according to the relative effects between cylinder pressure and reciprocating inertia. Therefore the patterns are classified into three regions; the inertia dominant region, the combined region, the pressure dominant region. In this paper, misfire detection was investigated according to the regions with parameters defined for misfire detection. By this method, the single misfire or multiple misfires can be detected

공기 보조 분사 장치를 이용한 엔진 성능 향상 및 연비 개선

김세웅,심국상,이근봉 金烏工科大學校 1995 論文集 Vol.16 No.-

This paper describes the improvement of engine performence and fuel consumption through improved combustion formed by the tumble and swirl flows of an in-cylinder fuel-air mixture that uses an air forced fuel injector(AFI) which used compressed air. The AFI is designed to promote fuel atomization and to form uniform fuel-air mixture. In order to make up the tumble and the swirl flows of the in-cylinder mixture, the end of AFI is attached to the tube containing the fuel-air mixture to ensure the adequate flow and to ensure that the remaining kinds of mixture will flow effectively. In order to investigate the improvement of engine performence and fuel consumption, 2 models of tubes which make tumble and swirl flows were utilized. Each model was examined according to engine speed, intake manifold pressure and excess air ratio and compared with a base engine. Compared with the base engine, the results show that the AFI improves the engine performance and the brake specific fuel consumption(BSFC) in all of the engine speeds and the boost pressures at the tumble and the swirlflows. It also decreases exhaust emission of hydrocarbon(HC)

보조 기구로 측정한 가솔린 기관의 배기 압력 특성

김영일,박경석,심국상,김세웅 金烏工科大學校 産業技術開發硏究院 1998 産業技術開發硏究 Vol.14 No.-

This paper describes the characteristics of exhaust pressure in the gasoline engine measures by assistant device. Each cylinder of engine has two pressure peaks during the one cycle, The first pressure peak is generated by blowdown and the second pressure peak is generated by residual burnt gas and movement of ascending piston during the displacement period. The first peak is higher than second peak. And these tendencies are not changed according to revolutions and loads of engine. The assistant device is installed behind of 3-way catalyst to increase the first peak and it is tested and compared with base condition. And it is also compared at the sixth position of exhaust system. The results show that the assistant device increase the first pressure peak and it is useful for detecting of misfired cylinder