• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.5
• /
• pp.700-706
• /
• 2012

The core technology of a starting device in the packaged power system is the pinion gear shifting device and to limit the initial starting voltage. Although the conventional products have been used the starting controller using mechanical contactor, these have a big problem such as the uncertainty for the start of starting motor after a pinion gear is completely shifted or the arc demage due to high current. In this study, in order to solve these problems, we designed and fabricated a new product to achieve the safety and reliability as follows: the pinion gear-shifting control circuits to eliminate the uncertainty of the start, the starting control system using semiconductor device to prevent the arc demage of contactor caused by high current, a start safety devices for soft starting of series motor. In addition, we obtained the electrical safety by separating the pinion gear control circuit and the source circuit of motor.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.774-780
• /
• 2021

The auxiliary power unit (APU) of a rotorcraft starts the engine during operation/flying. The APU is composed of a gas turbine engine type. The starting principle of the component is that the electric start motor generates the power required for starting by rotating the shaft. In this study, quality improvement was performed by applying an over-running clutch (ORC) between the APU and the starter motor to secure the operability of the starter motor of the APU mounted on the rotorcraft. The starter motor has the main role of starting the APU, but during operation, it is rotated without load by the rotational force of the APU gear shaft, resulting in friction at the brush. This phenomenon causes abrasion of the brush of the starter motor. Consequently, when the APU operation time increases, the brush life decreases, and the operability of the APU is affected. In this study, an ORC that separates the interlocking between the start motor brush abrasion and the APU operation time was applied to improve the operability/durability of the APU starter motor. The effect was verified through a test, and the technical feasibility of the design change was analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.05a
• /
• pp.250-250
• /
• 2004

자동차의 시동을 걸기 위해서는 맨 처음 엔진을 강제로 가동시키는 기계장치가 있어야 하며, 이를 시동모터라 한다. 시동모터는 모터부와 그 부속장치 그리고 발생된 힘을 엔진으로 전달하는 동력전달 기구로 구성되어 있다. 동력전달기구는 플라이 휠이라는 부품을 크랭크 축 끝단에 장착한 후 그 원주상에 링 기어를 만들고, 시동모터의 축에 피니언이라는 작은 기어를 맞물리게 하여 시동 키를 돌리면 이 기어가 회전되는 원리를 이용하고 있다. 피니언 기어는 작고 반대로 플라이 휠에 장착되어 있는 링 기어는 크기 때문에 일정한 기어비가 형성되어 큰 부하의 엔진회전이 가능하다.(중략)

• Journal of Energy Engineering
• /
• v.11 no.2
• /
• pp.178-185
• /
• 2002

The object of this paper is to investigate the effects of early fuel evaporators on cold driveability of gasoline passenger cars. Experiment has been carried out for the assessment cold start performance and cold driveability. And fuel consumption rate, emission and cylinder pressure were measured. On the base of combustion pressure of cylinder, rate of heat release, cumulative heat release amount and burned mass fraction are evaluated. The results show that fuel consumption rate is increased by 17.7%, monoxide and hydrocarbon were reduced by 23% and by 45% respectively, fluctuations of indicated mean effective pressure and maximum combustion pressure were increased by 4∼6%, fuel consumption rate per power was improved by 0.2∼2.3%. These are caused by the fact maximum heat release period and main combustion period are getting short.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1999.04a
• /
• pp.6-6
• /
• 1999

국가우주개발의 중장기 계획에 따른 우주 발사체 개발의 일환으로, 한반도 대기상태측정 등을 위한 고성능 과학관측로켓의 국산화를 위하여 항공우주연구소를 중심으로 여러 기관에서 연구가 진행되고 있다. 액체로켓을 주 추진체으로 삼고 있기 때문에 로켓의 안정적인 연소와 성능 향상이야말로 발사체 개발에 핵심이라고 할 수 있다. 액체로켓의 경우, 초기점화는 고체시동장치 또는 액체시동장치에 의한 방법 등으로 구분될 수 있다. 본 연구는 액체시동장치 중 hypergolic으로 초기점화를 하고 뒤이어 주추진제(LOX/kerosene)를 내보내어 주연소를 할 수 있는 Unlike impinging Quadlet injector(3 on 1)의 연소성능 이해와 예측을 위해 Cold flow test를 기초로 수행되었다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.1
• /
• pp.93-100
• /
• 2017

Four-stroke cycles in an automobile engine are suction stroke, compression stroke, combustion stroke and exhaustion stroke. A normal operation of engine in compression and power stroke must be processed in optimal fuel-air pressure. In this paper we describe a development of measuring equipment for engine cylinder pressure with observing supply current to self motor(start motor). By comparing the current wave on pressure of the 4 or 6 cylinder in engine, a abnormal cylinder state will be found. The validity of the proposed measuring equipment was shown by experiment for real automobile.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.13 no.5
• /
• pp.21-28
• /
• 2009

This experimental study was performed to find the important design parameters and the starting characteristics of a supersonic exhaust diffuser. The experimental study was carried out on a scaled down model of straight cylindrical supersonic exhaust diffuser, in order to evaluate the effects of operating fluid(air, nitrogen), the diffuser inlet area over the primary nozzle throat area($A_d/A_t$), the inlet pressure of primary nozzle, diffuser length over diffuser inner diameter($L_d/D_d$) and existence or nonexistence of diffuser divergence. The test results showed that the starting pressure increased with decrease in diameter of primary nozzle, and the measured starting pressure of the diffuser had approximately 90~98% efficiency as compared with the predicted starting pressure. Also, the diffuser was started at all case, regardless of $L_d/D_d$ (above 8.4) and diffuser divergence. The result of this study can be used as an essential database for developing a simulated high-altitude facility for real-scale model.

• Journal of the Korean Institute of Gas
• /
• v.15 no.3
• /
• pp.47-52
• /
• 2011

The purpose of this paper analyzes and studies to seek the failure examples of electronic control actuators for engine in liquified petroleum gas vehicle. The first, it was verified phenomenon for intial starting damage and no-acceleration of engine because of occasionally fuel feeding interception by clogged of emergency cutting solenoid valve filter. The second, the contact resistance produced in the connecting part of engine control relay because of no fully surface contacting by processes and assembly badness. It was displayed phenomenon of re-starting badness. The actuator that idle speed control system was sticked inside because of intake-air decreasing by carbon deposit. As a result, it was verified the phenomenon of disharmony that repeated up and down the engine revolution.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.1
• /
• pp.172-178
• /
• 2012

Packaged power systems are very convenient for transferring and installing, and can supply electric power steadily for the areas which have a great difficulty in drawing power line from the outside. Then, the equipments have been widely used in such mountain areas and the back of beyond. Generally, compressed air has been employed to start the dynamo-engines for P.P.S. However, these systems necessitate air compressors, air tanks, air starting motors and pipe lines for transferring compressed air etc. Recently, starting systems which have only batteries and series DC motors as whole automobiles have been applied due to their simplicity and economy. In this paper, developed new starting motor for the P.P.S. And we achieved the better results from performance tests.: Output power, torque and speed.

• Tribology and Lubricants
• /
• v.26 no.5
• /
• pp.277-282
• /
• 2010

The purpose of this paper is to study and analysis the failure examples for parasitic current leakage produced in starting system on gasoline engine. It verified the discharge of battery by electric leakage because of internal wiring damage problem for CD auto changer installed in car. Also, it verified the no-stating phenomenon because of deposit forming by chemical reaction of battery fluid between battery post and cable fixing parts. It verified the damage for brush holder and commutator mixing by internal short phenomenon because of brush carbon a particle and engine oil that was flowed into internal of starting motor. It verified the working phenomenon of audio by a point of contact even if the driver turn to "LOCK" position the key.