• Title/Summary/Keyword: 배기가변밸브

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Study on distributing Pressure and Velocity on Exhaust Variable Valve Face of Back Pressure (배기압력이 배기가변밸브 면에 분포하는 압력과 속도에 관한 연구)

  • Kim, Kwon-Se;Choi, Doo-Seuk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.1825-1830
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    • 2014
  • Environmental emission of recent automobile is drastically enhanced that it is one of the obvious assignments of exhaust system. This study is a purpose to establish of influence distribution on maxima and minima through the location of pressure on exhaust variable valve. The experiment are checked with real angles using camera which exhaust variable valve is opened side of point. Data has extracted to opening angles with internal flow, pressure. Exhaust variable valve through the floating analysis was analyzed the characteristic of location point about pressure and velocity. The pressures indicated the reduced results internal pressure within muffler. The velocity indicated an opposite results and vibration state of valve was verified to be operated as high speed from lower section. The conclusion to obtain from this study was found out the result to make the optimum back pressure condition as more increasing pressure distribution on valve face if the velocity location attracted by bottom point in order to improve for engine performance.

A Study on the Suitable Number of the Exhaust Variable Valve Spring for Semi-active Muffler (반능동형 머플러의 배기가변밸브 스프링 적정상수에 관한 연구)

  • Park Se-Jong;Seo Ho-Chul;Son Sung-Man;Park Kyoung-Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.5 s.182
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    • pp.137-142
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    • 2006
  • The muffler which reduce the exhaust noise and vibration from engine influence on the engine performance. Recently, exhaust variable valve has set up in the muffler controls the backpressure in the exhaust system. And the backpressure variation according to the exhaust variable valve opening has developed the engine performance. First, the preceding of structural analysis is needed and simulation experiment is requested for the study on the design factor to influence on the operation of the exhaust variable valve. In this study, setting up the various variables according to each composition element needed for the structural analysis of the exhaust variable valve, it is experimented the analysis on the influence of each design factor with the calculation of stress distribution and the displacement to cause about the backpressure for the valve through parameter study.

Effects of Intake and Exhaust Valve Timing on Combustion and Emission Characteristics of Lean-Burn Direct-Injection LPG Engine (직접분사식 희박연소 LPG엔진에서 흡배기 밸브시기가 연소 및 배기특성에 미치는 영향)

  • Park, Cheolwoong;Kim, Taeyoung;Cho, Seehyoen;Oh, Seungmook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.1
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    • pp.45-51
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    • 2015
  • In order to meet the enforced emission regulations and reduce fuel consumption, various new technologies are employed in engines. The problem of NOx emissions under a lean mixture condition should be solved, because a lean-burn direct-injection engine can realize stable lean combustion with a stratified mixture, which results in improvements in fuel economy and emissions. This study investigated the effects of intake and exhaust valve timing changes on the performance and emission characteristics of a lean-burn LPG direct-injection engine. Under a partial-load operating condition without throttling, an increase in the intake valve opening led to an increase in NOx emissions due to an increase in the amount of excess air. The fuel consumption deteriorated with an increase in the exhaust valve opening due to a decrease in the expansion work and an increase in the pumping loss.

Feasibility of Backfire Control and Engine Performance with Different Valve Overlap Period of Hydrogen-Fueled Engine with External Mixture (흡기관 분사식 수소기관의 밸브오버랩 기간 변화에 따른 기관성능과 역화억제 가능성)

  • Huynh, Thanh Cong;Kang, J.K.;Noh, K.C.;Lee, J.T.;Lee, J.H.
    • Transactions of the Korean hydrogen and new energy society
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    • v.18 no.1
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    • pp.67-74
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    • 2007
  • 고효율의 실현이 가능한 흡기관 분사식 수소기관의 역화 억제 가능성을 파악하고자 밸브 오버랩 기간의 변화에 따른 제반 기관성능과 역화가 발생되는 역화한계 당량비를 실험적으로 해석하였다. 실험에는 기계식 연속 가변밸브 타이밍 시스템이 부착된 연구용 수소기관을 사용하였다. 밸브 오버랩기간은 배기밸브 개폐시기를 고정하고 흡기밸브 캠의 위상각을 조절하여 변화시켰다. 해석결과 밸브 오버랩 기간의 감소에 따른 제반기관성능은 통상의 기관과 유사하지만 역화한계 당량비가 확장되어 초기 단계이지만 수소기관의 역화발생에 밸브오버랩 기간이 관여하는 것이 보였다. 기관 회전수 1600 rpm, WOT의 실험 조건에서 밸브 오버랩 기간을 $20^{\circ}CA$에서 $0^{\circ}CA$로 감소시킨 경우 역화한계당량비는 약 45% 정도 확장되고 정미 토크는 16% 감소했다.

Development of DC motor and Driving Controller for VVA Module of Gasoline Vehicle (가솔린 차량용 가변 밸브 DC 모터 및 제어기 개발)

  • Park, Joon-Sung;Gu, Bon-Gwan;Jung, In-Soung;Choi, Jun-Hyuk;Won, Chung-Yuen
    • Proceedings of the KIPE Conference
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    • 2010.07a
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    • pp.528-529
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    • 2010
  • VVA(Variable Valve Actuation) 기술은 엔진의 흡기 밸브 작동 모드를 가변하여, 엔진의 연비와 성능을 향상시키는 차세대 엔진 기술이다. 흡기캠에 의해 밸브가 직접 작동되는 일반 엔진과 달리 VVA 엔진은 흡기캠, VVA기구, 모터, 제어기 등에 의해 밸브 작동 모드가 정밀하게 제어되므로, 엔진에서 발생되는 손실을 줄여 연비가 크게 향상되고 엔진의 최고 성능이 향상된다. 또한 VVA 엔진을 장착한 차량은 차량의 발진 응답성이 향상되고, 배기가스 배출량을 줄일 수 있어 친환경 저연비 차량을 실현하는데 핵심 차량부품기술이다. 본 논문에서는 이와 같은 VVA 기구의 적용을 위한 DC모터 및 제어기를 개발하였다.

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Variation of Exhaust Gas Temperature with the Change of Spark Timing and Exhaust Valve Timing During Cold Start Operation of an SI Engine (스파크 점화기관의 냉시동시 배기밸브 타이밍 및 점화시기 변화에 따른 배기가스의 온도변화)

  • Yang Chang-Seok;Park Young-Joon;Cho Yong-Seok;Kim Duk-Sang
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.3 s.234
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    • pp.384-389
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    • 2005
  • Experimental study of variation of exhaust gas temperature was carried out with the changes of spark timing and exhaust valve timing during the cold start operation of an SI engine. To investigate the effects of these variables on combustion stability, cylinder pressure and exhaust gas temperature were measured and analyzed. Experimental results showed that exhaust gas temperature increased when spark and exhaust valve timings were retarded from the baseline cases. However, combustion stability during cold start deteriorated under the retarded conditions. To increase exhaust gas temperature for fast warmup of catalysts while maintaining combustion stability, an optimal condition for spark and valve timing retard should be appied for the cold start period.

Analysis of Swirl Flow and Combustion Characteristics by Variable Valve's Operation of Cam-In-Cam System based on GT-Power Program (GT-Power기반 Cam-In-Cam 가변밸브작동에 따른 스월유동 및 연소특성 해석)

  • Lee, Y.M.;Jo, I.S.;Kim, J.H.;Park, S.W.;Lee, J.W.
    • Journal of ILASS-Korea
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    • v.23 no.2
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    • pp.58-65
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    • 2018
  • An analytic strategy to control the variable valve actuation applied to two intake valves (flow port intake valve and swirl port intake valve) was performed in this study. we considered the variation in phasing of intake valve profiles by using the Cam-in-Cam technology. The analytic model was implemented in the GT-Power simulation program and analyzed the result of regulated emissions such as, NOx and Soot, especially with IMEP characteristics. Namely, we meticulously investigated the sources of having effect on the amount of NOx and soot formation under the test conditions with retard timing of both flow port and swirl port intake valves for decreasing the opening duration by 35CAD. Also, we analyzed the effect of incylinder pressure and temperature with NOx variations and in-cylinder pressure and temperature on NOx variations and normalized turbulent intensity. Through this analysis, some useful results on the combustion and flow characteristics of the swirl port and flow port control of the intake valve were obtained by this study.

A Study on the Back Pressure Characteristics and Engine Performance of Muffler with Exhaust Variable Valve (배기 가변 밸브를 적용한 소음기의 배압특성 및 엔진 성능에 관한 연구)

  • Park Kyoung-Suk;Park Se-Jong;Suh Ho-Chul;Son Sung-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.7 s.184
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    • pp.108-113
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    • 2006
  • Recently, Automobile manufactures have developing automotive exhaust system under consideration for improvement in engine performance. It thus develop many exhaust components. For example active muffler, semi-active muffler, electronic muffler etc. In this components consider enhanced back pressure and reduction noise. Especially, In recent years it develop the study of semi-active muffler. Semi-active muffler is simple structure and excel performance. Recently many forms semi-active muffler was developed and adopted to the actual use in consideration of cost and technical side for noise and vibration. This study had main objects about the recently developed the semi-active muffler. It was to show its combustion performance as well as its enhanced back pressure characteristics in design. Therefore if the precise analysis of the combustion pressure according to the back pressure transmission was carried out, it was understood that this study would be utilized in the design of the exhaust system such as the semi-active muffler.

Effect of Valve Lift and Timing on Internal Exhaust Gas Recirculation and Combustion in DME Homogeneous Charge Compression Ignition Engine (DME 예혼합 압축 착화 엔진에서 밸브 양정과 개폐시기가 내부 배기가스 재순환과 연소에 미치는 영향)

  • Jang, Jin-Young;Bae, Choong-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.4
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    • pp.93-100
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    • 2009
  • Intake/exhaust valve timing and exhaust cam lift were changed to control the internal exhaust gas recirculation (IEGR) and combustion phase of homogeneous charge compression ignition (HCCI) engine. To measure the IEGR rate, in-cylinder gas was sampled during from intake valve close to before ignition start. The lower exhaust cam made shorter valve event than higher exhaust cam and made IEGR increase because of trapping the exhaust gas. IEGR rate was more affected by exhaust valve timing than intake valve timing and increased as exhaust valve timing advanced. In-cylinder pressure was increased near top dead center due to early close of exhaust valve. Ignition timing was more affected by intake valve timing than exhaust valve timing in case of exhaust valve lift 8.4 mm, while ignition timing was affected by both intake and exhaust valve timing in case of exhaust valve 2.5 mm. Burn duration with exhaust valve lift 2.5 mm was longer than other case due to higher IEGR rate. The fuel conversion efficiency with higher exhaust valve lift was higher than that with lower exhaust valve lift. The late exhaust and intake maximum open point (MOP) made the fuel conversion efficiency improve.

Development of BLDC motor Controller for VVA Module of Gasoline Vehicle (가솔린 차량용 가변 밸브 BLDC 모터 제어기 개발)

  • Park, Joon Sung;Choi, Jun-Hyuk;Gu, Bon-Gwan;Kim, Jin-Hong;Jung, In-Soung
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.586-587
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    • 2012
  • 자동차 산업에 있어서 반도체 기술발전과 더불어 차량 내 기능들이 효율성, 경제성 및 친환경적인 관심을 고려하여 기계식 방식에서 전력전자식 방식으로 대체되고 있는 실정이다. 엔진의 연비를 향상시키기 위해서는 엔진의 연소효율을 개선하거나, 엔진에서 발생되는 손실을 줄이는 것이 필요한데, VVA(Variable Valve Actuation, 가변 밸브 작동) 기술은 엔진 흡기 유동 강화, 펌핑 손실 저감, 기계적 마찰 손실 저감등을 통해 엔진의 연비를 향상시킬 수 있다. 또한 VVA 엔진을 장착한 차량은 차량의 발진 응답성이 향상되고, 배기가스 배출량을 줄일 수 있어 친환경 저연비 차량을 실현하는데 핵심 차량부품기술이다. 최근까지 차량의 전동기 구동의 경우 DC모터 방식이 많이 적용되어 왔으나 DC모터의 내구성 및 효율 등의 이유로 BLDC모터로 바뀌고 있는 추세이다. 본 논문에서는 이와 같은 VVA 기구의 적용을 위하여 BLDC모터 제어기를 개발하였다.

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