EGR SYSTEM

• Main Authors: YOSHIOKA MAMORU, CAO HAIXIANG, KAWAI SHINJI, BESSHO TAKASHI
• Format: Patent
• Language: English; Japanese
• Published: 08.02.2022
• 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

To lower a temperature of high-temperature EGR gas flowing from an exhaust passage to an EGR passage to an appropriate temperature and then cause the EGR gas to flow to a resin downstream side EGR passage so as to suppress melting loss of the downstream side EGR passage and generation of condensation water in the downstream side EGR passage in an EGR system.SOLUTION: An EGR system includes: an EGR valve 14 controlling an EGR gas flow rate in an EGR passage 12; an EGR cooler 13 having a heat exchanger 32 exchanging heat between EGR gas and engine cooling water for cooling the EGR gas flowing in the EGR passage 12; a bypass passage 16 bypassing the EGR gas flowing to the heat exchanger 32 of the EGR cooler 13; a bypass valve 17 opening/closing the bypass passage 16; and a resin EGR gas distributor 15 provided downstream of the EGR cooler 13 and the bypass passage 16. The bypass valve 17 includes: a valve element 21; and an actuator 22 configured to close the valve element 21 from the opened state when a temperature of the EGR gas or a temperature of the cooling water reaches a first predetermined value or greater.SELECTED DRAWING: Figure 1 【課題】ＥＧＲシステムにおいて、排気通路からＥＧＲ通路へ流れる温度の高いＥＧＲガスを適度な温度に低下させて樹脂製の下流側ＥＧＲ通路へ流し、その下流側ＥＧＲ通路の溶損とその下流側ＥＧＲ通路での凝縮水の発生を抑制すること。【解決手段】ＥＧＲシステムは、ＥＧＲ通路12にてＥＧＲガス流量を調節するＥＧＲ弁14、ＥＧＲ通路12を流れるＥＧＲガスを冷却するためにＥＧＲガスとエンジン冷却水との間で熱交換を行う熱交換器32を含むＥＧＲクーラ13、ＥＧＲクーラ13の熱交換器32へ流れるＥＧＲガスを迂回させるバイパス通路16、バイパス通路16を開閉するバイパス弁17、ＥＧＲクーラ13及びバイパス通路16より下流に設けられる樹脂製のＥＧＲガス分配器15を備える。バイパス弁17は、弁体21と、ＥＧＲガスの温度又は冷却水の温度が第１所定値以上となるときに弁体21を開いた状態から閉じるように構成されたアクチュエータ22を含む。【選択図】 図１