CONTROL DEVICE FOR ENGINE

• Main Authors: TSUBOI GORO, NISHIMURA HIROYUKI, MIZUTA YOSHIO, YAMADA KEIJI, SATO YOSHIYUKI, HAYASHIBARA HIROSHI
• Format: Patent
• Language: English; Japanese
• Published: 22.08.2019
• Subjects: BLASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; STEAM ENGINES; SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLEMIXTURES OR CONSTITUENTS THEREOF; THEIR RELEVANT APPARATUS; TRANSPORTING; WEAPONS

To more efficiently eliminate S-poisoning of a NOx catalyst.SOLUTION: A control device 200 for an engine which includes an EGR valve 60, an oxidation catalyst 42, a NOx catalyst 41 provided integrally therewith or on the downstream side thereof, and a DPF 44 provided on the downstream side of the oxidation catalyst 42, includes a NOx catalyst regeneration control part 202 for repeating more than once a rich-lean cycle including a rich step of actualizing a rich state that the air-fuel ratio of exhaust gas to be introduced into the NOx catalyst 41 is a theoretical air-fuel ratio or a richer air-fuel ratio and a lean step of actualizing a lean state that it is a leaner air-fuel ratio where unburnt fuel is introduced into the oxidation catalyst 42, to remove SOx from the NOx catalyst 41, and a PM filter regeneration control part 203 for removing PMs from the DPF 44. The NOx catalyst regeneration control part 202 controls the valve opening of the EGR valve 60 in the rich step to be closer to the closed side in the cycle to be executed earlier than in the cycle to be executed later.SELECTED DRAWING: Figure 8 【課題】ＮＯｘ触媒のＳ被毒をより効率的に解消する。【解決手段】ＥＧＲバルブ６０と、酸化触媒４２と、これと一体又はこの下流側に設けられたＮＯｘ触媒４１と酸化触媒４２の下流側に設けられたＤＰＦ４４とを備えたエンジンの制御装置２００は、ＮＯｘ触媒４１に導入される排気ガスの空燃比が理論空燃比又はリッチ空燃比であるリッチ状態に設定するリッチステップと、リーン空燃比かつ未燃燃料が酸化触媒４２に導入されるリーン状態に設定するリーンステップとを含むリッチリーンサイクルを複数サイクル繰り返すことにより、ＮＯｘ触媒４１からＳＯｘを除去するＮＯｘ触媒再生制御部２０２と、ＰＭをＤＰＦ４４から除去するＰＭフィルタ再生制御部２０３とを備え、ＮＯｘ触媒再生制御部２０２は実施時期が早いサイクルの方が遅いサイクルよりリッチステップにおけるＥＧＲバルブ６０のバルブ開度を閉じ側に制御する。【選択図】図８