• Title/Summary/Keyword: Automotive lift

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Experimental Study on Effect of TiN - Coating on a Cold Forging in Surface Characteristics (냉간단조 공정에서 TiN 코팅이 제품의 표면특성에 미치는 영향에 관한 실험적 연구)

  • Kim Hae Ji;Lee Sang Wook;Kang Sang Myoung;Joun Byung Yun;Joun Man Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.1
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    • pp.47-52
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    • 2005
  • In this paper, the effect of TiN-coating on product quality such as dimensional accuracy and surface roughness is experimentally investigated. A punch of SKD11 material in cold forging an automotive bearing shaft and its related process found in a cold forging company are selected as the test example. The effect of TiN-coating is revealed in a quantitative manner. It is to be noted that TiN-coating is effective in controlling the dimensional accuracy and surface roughness as well as in increasing tool lift.

Visualization of the Flow in a Diesel Injection Nozzle In case of the Steady Flow Condition (정상류 조건에서의 디젤 연료 분사 노즐내의 유동가시화)

  • 김장헌;송규근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.49-56
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    • 1999
  • The effects of the internal flow in a D.I. Diesel injection nozzle on the atomization of a spray were analyzed experimentally. Flow visualization studies were made using a transparent acrylic model nozzle as a diesel nozzle . Water instead of disel fuel was used as the injection liquid. The geometry of the model nozzle was scaled up 10 times of the actual nozzle and the injection pressure for the model nozzle was adjusted so as to achieve a Reynolds number at the discharge hole that was the same as the actual nozzle. Experimental results show that when the needle lift was small, the high turbulence in the sac chamber generated by the high velocity seat flow made the spread angle of the spray plume large. Cavitation, which arose from the sac chamber, makes the spread angle of the spray plume large but the discharge coefficient small.

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Effect of Piston Ring Gap on the Axial Motion of Piston Ring and Oil Consumption (피스톤 링갭이 링거동 및 오일소모에 미치는 영향)

  • 민병순;김중수;최재권
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.197-204
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    • 1997
  • In order to investigate the relationship between the ring gap ratio and oil consumption, the axial motion of piston ring was measured by capacitance technique. The pressures of each land and the motions of each ring were calculated by orifice-volume method in which it is assumed that the ring gaps are the only gas leakage paths. The calculated results were compared with the measured ones. Consequently, it is known that the increase of ring gap ratio has the effect of lifting the first ring. The calculated results were roughly in accordance with those measured. Therefore, it is possible to predict the effect of design variables on the pattern of ring motion. It is known that the lift off of first ring accompanied by the increase of ring gap ratio make rise of oil consumption.

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Fatigue Durability Analysis and Evaluation for Straighted Type Exhaust System of Automobile (자동차용 직선화 배기시스템의 피로내구 해석 및 평가)

  • Park Sejong;Suh Hocheol
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.147-152
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    • 2005
  • The exhaust system of automobile is faced with random or spectrum types of fatigue loads during usage life and so needs to be closely estimated for quality and performance to have enough certainty on design endurance lift during preliminary design process. Structural operation conditions, operation load history, property of material and manufacturing process etc. should be considered by performing experiment approach. Using the software program for predicting fatigue life quickly and exactly in preliminary design stage saves plenty of time and cost generated by fatigue tests. In this paper, fatigue life prediction was performed on the basis of fatigue analysis using MSC/FATIGUE and load data from field test and the life of development items was estimated and compared through the results.

Intake Flow Simulation in a D.I. Engine Cylinder (디젤엔진 흡입과정에서 실린더내의 시뮬레이션)

  • 강신형;김응서;송명호
    • Journal of the korean Society of Automotive Engineers
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    • v.8 no.2
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    • pp.65-74
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    • 1986
  • A computer program was developed to predict swirling steady axisymmetric turbulent flows by extending TEACH Code. It was applied to a reciprocating engine cylinder with a intake valve on the flat head. Flows were assumed to be steady and swirling. Effects of Reynolds number, the valve lift, and the swirl ratio on flow patterns and turbulence were investigated numerically. Flow patterns were reasonably predicted in comparison with experimental results. Length of the recirculation zone was shortened with increasing valve lifts and swirl ratios. Static pressure distributions show maximum value near the reattachment point of the incoming circular jet and minimum value near the maximum width of the valve attached recirculation zone.

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A Study on Combined Effects between Swirl and Tumble Flow of Intake Port System in Cylinder Head (엔진 흡입포트 시스템 유동특성 규명을 위한 스월-텀블 합성효과에 관한 연구)

  • 윤정의
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.8
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    • pp.76-82
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    • 1999
  • The object of this study is to find new evalution index for in-cylinder flow characteristics insteady of current swirl, tumble coefficient using steady flow test rig on intake port system. To this end, port flow rig test was conducted on DOHC head varying intake valve lift respectively. Finally combination angular coefficient and inclination angle were introduced as new evaluation index for in-cylinder angular flow characteristics.

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Characteristics of Solenoid Actuated Hydrogen Injector (솔레노이드 구동 수소인젝터의 성능특성)

  • Yi, H.S.;Kim, H.J.;Kim, E.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.6
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    • pp.134-144
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    • 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.

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Modelling of an Automotive Block Type Thermostatic Expansion Valve (자동차용 블록식 온도감응 팽창밸브의 모델링)

  • Won, Sung-Pil
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.4
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    • pp.251-258
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    • 2011
  • The objective of this study is to propose two empirical correlations to predict the mass flow rate through an automotive block type thermostatic expansion valve and then to evaluate the correlations. The first correlation is deduced by modifying the basic equation of the orifice meter for the mass flow rate and the second correlation is deduced by using the Buckingham's ${\pi}$ theorem. The first correlation showed very good agreement on the measured data for R134a, given by Monforte. Average relative deviation and standard deviation of it are 2.5% and 1.6%, respectively. The second correlation agreed on the same measured data with a little greater deviations. The two correlations may apply to common expansion valves which have different geometrical sizes of the same shape.

Prediction Modeling of Unburned Hydrocarbon Oxidation in the Exhaust Port of a Propane-Fueled SI Engine (프로판 엔진의 배기 포트에서 탄화수소 산화 예측을 위한 모델링)

  • 이형승;박종범;최회명;민경덕;김응서
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.2
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    • pp.33-40
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    • 2000
  • In order to investigate the exhaust structure and secondary oxidation of unburned hydrocarbon (HC) in the exhaust port, a numerical simulation was performed with 3-dimensional flow model and oxidation mechanism optimized for port oxidation. To predict the exhaust and oxidation process with consideration of flow, mixing, and temperature, 3-dimensional flow model and HC oxidation model were used with a commercial computational program, STAR-CD. The flow model were with moving grid for valve motion, which could predict the change of flow field with respect to valve lift. Optimization was performed to predict the HC oxidation with temperature range of 1200~1500K, low HC and oxygen concentration, existence of intermediate species, as typical in port oxidation. The constructed model could predict the port oxidation process with oxidation degree of 14~48% according to the engine operation conditions.

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An Effect of Roof-Fairing and Deflector System on the Reduction of Aerodynamic Drag of a Heavy-Duty Truck (대형트럭용 루프 훼어링과 디프렉트의 공기저항력 저감 특성에 관한 연구)

  • Kim, Chul-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.194-201
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    • 2006
  • Roof-fairing and deflector system have been used on heavy-duty trucks to minimize aerodynamic drag force not only for driving stability of the truck but also for energy saving by reducing the required driving power of the vehicle. In this study, a numerical simulation was carried out to see aerodynamic effect of the drag reducing device on the model vehicle. Drag and lift force generated on the five different models of the drag reducing system were calculated and compared them each other to see which type of device is efficient on the reduction of driving power of the vehicles quantitatively. An experiment has been done to see airflow characteristics on the model vehicles. Airflow patterns around the model vehicles were visualized by smoke generation method to compare the complexity of airflow around drag reducing device. From the results, the deflector systems(Model 5,6) were revealed as a better device for reduction of aerodynamic drag than the roof-fairing systems(Model 2,3,4) on the heavy-duty truck and it can be expected that over 10% of brake power of an engine can be saved on a tractor-trailer by the aerodynamic drag reducing device at normal speed range($80km/h{\sim}$).