• 한국자동차공학회논문집
• /
• 제5권1호
• /
• pp.9-14
• /
• 1997

The pump-pipe-injector system is that most commonly used type of injection equipment for diesel engines. In this study, a new electromagnetic fuel injection system was designed and carried out the experiment of single cylinder direct injection(DI) diesel engine. This system do not need the cam shaft for fuel injection. The effects of the injection timing on the combustion process and emission were investigated. The results are that 1) atomization was improved, 2) combustion pressure was increased and ignition delay became shorter than before, 3) Low smoke level guarantee with more advanced injection timing without abnormal combustion but NOX concentration was increased as the injection time advanced.

• 한국자동차공학회논문집
• /
• 제8권5호
• /
• pp.78-85
• /
• 2000

This study is to develop the diesel engine which has 6 cylinder natural aspiration direct injection type of 7.4$\ell$ with high performance, low emissions and low fuel consumption Finally the developed engine meets Korean `98 exhaust emission regulation for the city bus of heavy duty diesel engine by optimizing the various combustion parameters affecting performance and exhaust emissions. Combustion parameters are the swirl ratio of intake ports, the profile of injection pump`s cam affecting injection pressure, the design features of piston bowl of injection pump`s cam affecting injection pressure, the design features of piston bowl of combustion chamber and injector`s hole size. Through experimental analysis, various combustion parameters are optimized and the results are as follows; the swirl ratio is 2.20, the profile of injection pump`s cam is concave and re-entrant ratio, inner diameter of piston bowl and hole diameter of injector is 0.88,$\psi$64.0mm and $\psi$0.25mm respectively.

• 한국생산제조학회지
• /
• 제19권6호
• /
• pp.812-828
• /
• 2010

A fuel injection system using an ECU HILS as an alternate to a vehicle test for the fuel injectors was developed. The throttle position, vehicle speed, engine speed, crank position, cam position, intake air flow, and several other sensor signals that are supplied to the ECU were measured and recorded as a data file for a vehicle driven in the FTP-75 mode in a chassis dynamometer. Electric signals that are equivalent to the sensor signals from the vehicle are reconstructed from the recorded data file using data acquisition boards, microprocessors, and computers. All sensor signals are supplied to the ECU with synchronized timing using a computer program. The findings show that the cost and time of vehicle experiments can be reduced using the ECU HILS system. Moreover, the repeatability of the generation of sensor signals can enhance the accuracy of a range of experiment related to vehicle testing. An ECU scanner that scans the sensor signals that are input to the ECU through a serial port was used to assess the accuracy of the reconstructed signals. The scanning results show good agreement with the reconstructed input signals. Injectors were connected to the ECU HILS system and were driven by the system to measure the quantity of injected fuel.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1998년도 제28회 추계학술대회
• /
• pp.30-37
• /
• 1998

It is well known that reduction of friction loss due to the valve train system greatly affects on improvement of fuel economy in internal combustion engine. In order to investigate friction characteristics of valve train system we carried out friction force measurement using test rig developed by ourselves. From test results, we concluded that characteristics of lubrication and friction torque on the valve train system such as mixed and hydrodynamic was mainly governed the contact type between cam and tappet.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2004년도 International Symposium on Powder Materials and Processing
• /
• pp.5-6
• /
• 2004

• 한국수소및신에너지학회논문집
• /
• 제28권6호
• /
• pp.675-682
• /
• 2017

New government, the market for stationary fuel cell systems in domestic is expected to expand in line with the policy for expanding new and renewable energy. In order to promote and expand the domestic market for stationary fuel cell systems, it is required to do research and develop for cost reduction and efficiency improvement technologies through the localization of BOP. In this study, the safety performance including the power consumption, flow rate, noise and air-tightness of the domestic fuel booster blower and the foreign fuel booster blower was evaluated and the performance improvement of the domestic blower was confirmed. As a result of the power consumption measurement and the flow rate according to the back pressure of the A company 2nd prototype and B company, the values were 73 W, 27 LPM, and 55 W, 25 LPM. These results are attributed to the improvement of performance through design changes such as CAM angle and diaphragm material.

• 한국자동차공학회논문집
• /
• 제22권3호
• /
• pp.42-49
• /
• 2014

The gasoline direct injection (GDI) system is considerably spreading in automotive market due to its advantages. Nevertheless, since GDI system emit higher particle matter (PM) due to its combustion characteristics, it is difficult to meet strengthened emission regulation in near future. For this reason, a combined GDI with MPI system, so-called, dual injection (DUI) system is being investigated as a supplemental measure for the GDI system. This paper focused on power and fuel consumption effect by injection mode strategy of DUI system in part load and idle engine operating condition. In this study, port fuel injectors are installed on 2.4 liters GDI production engine in order to realize DUI system. And, at each injection mode, DOE (design of experiment) method is used to optimize engine control parameters such as dual injection ratio, start of injection timing, end of injection timing, CAM position and so on. As a consequence, DUI mode shows slightly better or equivalent fuel efficiency compared to conventional GDI engine on 9 points fuel economy mode as well as MPI mode shows less fuel consumption than GDI mode during idle operation. Furthermore, DUI system shows improvement potential of maximum 2.0% fuel consumption and 1.1% performance compared to GDI system in WOT operating condition.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.448-452
• /
• 2008

2-stroke marine diesel engine has generally one exhaust valve and three fuel injection nozzle which are key component for engine's performance and combustion. Fuel injection and exhaust valve driving system are driven by rotating of camshaft. Rotation of crank shaft drives the cam shaft through gear train that is composed of $3{\sim}4$ gear wheels. Gear column supporting the gear wheel has to bear against the dynamics forces by engine running as well as gearing forces. In this paper, structural analysis for engine structure and fatigue strength assessment of welded joint is shown. Repeatedly full cyclic simulation during one cycle is performed to investigate the structural behavior of engine. Fatigue analysis is carried out based on IIW using submodeling technique to obtain more detailed stress distribution.

• 에너지공학
• /
• 제14권3호
• /
• pp.180-186
• /
• 2005

실험에 사용된 엔진은 $3000\~12000$ RPM의 광범위한 회전수범위를 가지고 있어 엔진성능을 향상시키기 위해서는 다양한 제어장치가 필요하다. SCV는 저회전수에서 엔진의 성능을 개선시키기 위한 방법 중의 하나로 자주 언급되어지고 있다. 본 연구에서는 소형고속엔진에 SCV를 장착하여 저회전수 범위에서 SCV가 엔진에 미치는 영향에 대해 조사하였다. 실험에서는 4valve SOHC 공랭식 단기통 엔진에 SCV의 형상에 따른 스월 강도, 출력, 연료소비율, 배기가스를 조사하였다 그 결과 SCV의 사용 가능 범위 5000 RPM에서 연료소비율 $9\%$의 저감효과를 보았다.

• 한국자동차공학회논문집
• /
• 제14권2호
• /
• pp.166-173
• /
• 2006

This study investigates a heavy duty diesel engine with swept vol. 12.6L, 4cycle-OHC type to verify the effects of the performance and exhaust gas emission according to the variable specifications of both swirl ratio and flow coefficient in inlet port, combustion bowl and fuel injection system. To meet the high BMEP and stringent exhaust emission standard, a turbocharger with wastegate and an intercooler were installed in the engine. Helical port, major design parameters for combustion chamber and electronic fuel injection pump with 1,000bar were reviewed and applied. Confirmation tests were also performed to meet the target value, $NO_x$ 5.0g/kWh and PM 0.1g/kWh of Euro3 exhaust emission legislation. The results of this study show that not only is it effective to use a relatively bigger bowl size for controlling rapid burning condition due to the decreased in-bowl swirl, but also to use a concave cam with double injection rates to decrease $NO_x$.