EGR DEVICE AND EXHAUST GAS RECIRCULATION METHOD

• Main Authors: KAJIYAMA MASAHIRO, SUGAYA YUKI, SHIOYASU KENTA
• Format: Patent
• Language: English; Japanese
• Published: 30.03.2015
• Subjects: BLASTING; COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLEMIXTURES OR CONSTITUENTS THEREOF; WEAPONS

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