• Transactions of the Korean Society of Automotive Engineers
• /
• v.3 no.6
• /
• pp.134-144
• /
• 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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.26-33
• /
• 2004

In this study, a boundary-layer bleeding and a two-staged fuel injection were applied to a scramjet engine for suppressing unstart transition and improving the thrust performance under Mach 6 flight conditions. With the boundary-layer bleeding, the engine could operate without unstart transition around at the fuel equivalence ratio of unity ($\Phi$ = 1). The thrust increment from the no fuel condition (dF) increased to 2460 N, which was about 1.4 times as large as that of the case without the bleeding and maximum in our Mach 6 tests. It was confirmed that the boundary-layer bleeding suppressed the separation during the engine operation. The two-staged fuel injection was less effective for improving the thrust performance com-pared with the single-staged one with the bleeding at Mach 6.

• International Journal of Automotive Technology
• /
• v.6 no.5
• /
• pp.507-511
• /
• 2005

Recently, many solution have been suggested to development of plastic products. Among many manufacturing technologies for plastic parts, the injection molding process is very attractive because of its low production cost and short cycle time. In this paper, the plastic ball seat of a ball joint, one of the essential components for automotive suspension or steering system, was studied to enhance its mechanical performance and durability by using PA66 that is reinforced polymeric plastic resin. But ball seat has some trouble in manufacture process. And strength of molded part is not enough to use. For the quality stabilization and reliability of injection molded parts, we designed the mold cavities through analytical simulation software and tested the mechanical performance for the injection molded ball-seat parts. After modification, tensile strength increases by about $13.5\%$. Strength and quality stabilization is improved.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.2
• /
• pp.638-643
• /
• 2019

In order to reduce the cost and weight of the soft-foamed instrument-panel (IP), it was developed the new IP which is made by the two kinds of injection methods. One is the compression-injection with back-foamed foil inserted, and the other is two-shot injection with the passenger airbag door. We named it 'IMX-IP' which means that all components ('X') of the IP with different resins are made in a mold. The development procedure of this technology was introduced (1) Design of the new injection mold through TRIZ method, (2) Optimization of the injection conditions and back foamed-foil for minimizing the foam loss and thickness deviation, (3) Development of CAE for two-shot injection compression, (4) Reliability performance test and application to the mass production. The reduction of the processes through the two-shot injection with back foamed-foil inserted made it possible to enhance soft feeling on IP and reduce the cost and weight simultaneously.

• Journal of Power System Engineering
• /
• v.2 no.2
• /
• pp.27-34
• /
• 1998

The purpose of this study is to investigate the performance of swirl combustion chamber diesel engine by changing the jet passage area and its angle, the depth and shape of the piston top cavity(main chamber). The performance of diesel engine with newly changed swirl combustion chamber was tested through the experimental conditions as engine speed, load and injection timing etc. The test results were compared and analyzed. The rate of fuel consumption was affected significantly by the jet passage area at the high speed and load, by the depth of the piston top cavity at the low speed and load. The exhaust smoke density and exhaust gas temperature depended sensitively on variation of the injection timing rather than the shape of the combustion chamber within the experimental conditions.

• Journal of Energy Engineering
• /
• v.14 no.3 s.43
• /
• pp.187-193
• /
• 2005

In this study, the performance and emission characteristics of a liquefied petroleum gas (LPG) engine converted from a diesel engine were examined by using mixer system and liquid propane injection (LPi) system. A compression ratio of 21 for the base diesel engine, was modified to 8, 8.5, 9 and 9.5. The engine performance and emissions characteristics are analyzed by investigating engine power, brake mean effective pressure (BMEP), brake specific fuel consumption (BSFC), volumetric efficienry, CO, THC and NOx. Experimental results showed that the LPi system generated higher power and lower emissions than the conventional mixer fuel supply method.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.2 no.2
• /
• pp.117-123
• /
• 1994

This paper describes the effect of air assisted fuel injection system(AAI) using compressed air to improve the performance of lean combustion engine. AAI is designed to promote fuel atomization and intake flow. In order to investigate the performance of engine with AAl, experiments are conducted varying the engine revolution speed, lean air-fuel ratio and intake manifold pressure. Compared with the original engine, the performance of the engine with MI is improved as the air-fuel mixture becomes leaner or the engine load becomes lower. The descreasing rate of BSFC is propotional to the relative air-fuel ratio and the lean misfire limit extended more than 0.2 relative airfuel ratio.

• Asian-Australasian Journal of Animal Sciences
• /
• v.9 no.1
• /
• pp.101-106
• /
• 1996

This experiment was conducted to investigate the effect of bST administration on growth performance and carcass characteristics of finishing Korean native bulls. Fifty four Korean native bulls of about 14 months of age weighting an average 420 kg were assigned to receive no injection of bST, 250 mg of bST s.c. injection every week, or 500 mg bST s.c. injection every 2 weeks (Control, 250ST, 500ST) in a $3{\times}3$ randomized block design for a period of 20 weeks Animals administered with bST responded with decreased feed DMI by 8%(p < 0.01), increased ADG by 12%(p < 0.05), and increased gain/feed ratio by 20%(p < 0.01). But there was no significant difference in the growth performance between 250ST and 500ST. Administration of bST increased dressing percentage by 1.8%(p < 0.05), and tended to increase longissimus muscle area and decrease backfat thickness and marbling score.

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.726-731
• /
• 2000

This study was experimentally analyzed to improve the performance and to reduce exhaust emissions in a turbochaged D.I. diesel engine of the displacement 9.4L. In generally, the system of intake port, fuel injection and turbocharger are very important factors which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. The optimum results which is tested as available factors fur better performance and emission are as follows; the swirl ratio is 2.43, compression ratio is 16, combustion bowl is $5^{\circ}$ re-entrant type, nozzle hole diameter is ${\phi}0.28*6$, injection timing is BTDC $13^{\circ}CA$ and turbocharger is GT40 model which are selected compressor A/R 0.58 and turbine A/R 1.19.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.5
• /
• pp.7-14
• /
• 2003

Exhaust Gas Recirculation (EGR) system is used to reduce NOx emission, to improve fuel economy, and to suppress knock since it offers the benefits of the inlet charge dilution. The effects of EGR was investigated on the performance and emission to reduce exhaust thermal load with a single cylinder liquid-phase LPG injection engine, in a wide range of EGR rate, engine conditions and LPG proportions. As EGR rate was increased, NOx was reduced while HC was increased. Pumping loss reduction by EGR improved bsfc and increased EGR lowered exhaust gas temperature. And, LPG proportions were made a difference on the performance and emission characteristics.