http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김희붕(Heuiboong Kim) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
At the design validation phase of a small diesel engine development for passenger vehicle, the erosion corrosion phenomenon was found in the cylinder head. As a result of fully developed erosion corrosion, a coolant tunnel connecting water jacket at the cylinder head to combustion chamber was the start of unexpected coolant consumption at the combustion chamber. To prevent engine failure prior to life target, possible root causes of erosion corrosion were investigated and the complementary measures increased effective expected engine life. The conclusions are; 1) higher temperature on the local surface of water jacket can make an erosion corrosion by micro boiling of coolant. 2) the direction of erosion corrosion progression is toward higher temperature such as combustion chamber or exhaust port. 3) higher temperature of combustion chamber can accelerate erosion corrosion. 4) properly secured velocity of coolant flow at the water jacket can remove erosion corrosion by moved micro-boiling.
조준영(Junyoung Jo),김희붕(Heuiboong Kim),김유식(Yoosik Kim) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5
In an internal combustion engine, a cam drive system is used to drive valve train, auxiliary devices, driven by timing sub-system. A camshaft which consists of complicated configurations such as cam journals, lobes, lateral guides, notches, fillets and oil feeding holes can be sometimes fractured in the weak area by fatigue crack growth caused by combined cyclic load from timing sub-system tension, valve spring force and air motions. During the engine validation test, the first neck of camshaft had been broken several times and it was suspected as the fatigue fracture. To define the root cause of the issue, strain on the broken area with respect to several engine operation conditions was measured by using the strain gauge and fatigue stresses were calculated. In addition, fatigue life was predicted in GM standard engine durability test cycles based on the experimental measured data and analysis with variable design factors. As a result of this research, optimal design for camshaft were proposed to prevent fatigue fracture.
Oil Ring End Gap 이 오일소모에 미치는 영향
조영한(Younghan Cho),전제혁(Jehyeuk Jeon),김희붕(Heuiboong Kim) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11
A reduction in piston ring friction would result in higher efficiency, lower fuel consumption and reduced emissions. So low tension rings that exert less pressure against cylinder walls than conventional rings are used in most engines today. But an increase in oil consumption can be predicted to occur with the low tension oil control ring design. It is generally known that the increase of oil ring tension with the minimum end gap is the well-known method to control oil consumption. However, from the result of this study, it was seen that the minimum oil ring end gap in low tension ring design could give the negative effect in oil consumption. Therefore, it is expected that the optimized larger oil ring end gap with low tension rings can be used as the achievement of low oil consumption.
차세대 알루미늄 피스톤의 신뢰성 검증을 위한 내구특성 평가
조일환(Ilhwan Jo),이형상(Hyungsang Lee),김희붕(Heuiboong Kim),장현모(Hyunmo Jang),김동연(Dongyeon Kim),김숭기(Soongkee Kim) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4
Each automobile company has their own process to validate durability characteristic of their own product. As customer has been focusing initial quality of vehicle, automobile companies try to improve their validation process and work up to enhance initial quality and durability. In case of engine development, engine must be validated its durability characteristic at max load and max power condition, speed transient condition, hot & cold condition and each engine's specific running condition. In this study, after increasing combustion pressure up to 180 bar, initial durability validation cycle which is consisted of high load & high power condition, city cycle condition and vehicle simulation cycle condition was applied for verifying next generation aluminum piston durability characteristic.