EGR DEVICE AND EXHAUST GAS RECIRCULATION METHOD

PROBLEM TO BE SOLVED: To provide an EGR device and an exhaust gas recirculation method which can prevent an exhaust gas from generating HC during early warm-up control thereof and under a low load by changing use of an EGR cooler depending on whether or not the exhaust gas is under early warm-up con...

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Bibliographic Details
Main Authors KAJIYAMA MASAHIRO, SUGAYA YUKI, SHIOYASU KENTA
Format Patent
LanguageEnglish
Japanese
Published 30.03.2015
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Summary:PROBLEM TO BE SOLVED: To provide an EGR device and an exhaust gas recirculation method which can prevent an exhaust gas from generating HC during early warm-up control thereof and under a low load by changing use of an EGR cooler depending on whether or not the exhaust gas is under early warm-up control and an operation state of the engine in a manner that introduces a high-temperature EGR gas, when cooling the EGR gas is not required, directly into a cylinder without letting the EGR gas pass through the EGR cooler.SOLUTION: The EGR device recirculates an exhaust gas Ge using an EGR bypass passage 24 which circumvents an EGR cooler 22 when early warm-up control to increase a temperature of the exhaust gas Ge is not executed and an operation region of an engine 10 is in a first low load region Ra or when the early warm-up control is executed and the operation region of the engine 10 is in the first low load region Ra or a second low load region Rb having a load larger than the first low load region Ra. 【課題】早期昇温制御中であるか否かと、エンジンの運転状態とにより、EGRクーラを使い分けて、EGRガスの冷却が不要なときには、EGRガスをEGRクーラを通過させずに、温度の高いEGRガスをシリンダ内に導入して、排気ガスの早期昇温制御中や低負荷時にHCが発生することを防止できる、EGR装置及び排気ガス還流方法を提供する。【解決手段】排気ガス温度を上昇させる早期昇温制御中でない場合でエンジン10の運転領域が第1低負荷領域Raであるとき、及び、早期昇温制御中の場合でエンジン10の運転領域が第1低負荷領域Ra又は第1低負荷領域Raよりも負荷が大きい第2低負荷領域Rbであるときは、EGRクーラ22を迂回するEGRバイパス通路24を用いて排気ガスGeを還流する。【選択図】図3
Bibliography:Application Number: JP20130195781