INTERNAL COMBUSTION ENGINE, AND FUNCTION RECOVERY METHOD OF EXHAUST GAS AFTER-TREATMENT DEVICE

PROBLEM TO BE SOLVED: To provide an internal combustion engine and a function recovery method of an exhaust gas after-treatment device capable of preventing heat damage of a reduction catalyst, and recovering a function of the after-treatment device while preventing degradation of fuel consumption, evan when an oxidation catalyst arranged at an upstream of the reduction catalyst without interposing a collecting device is deteriorated.SOLUTION: A function recovery method includes determination means 44 for determining deterioration of a first oxidation catalyst 31, and a control device 40 is constituted so that function recovery control is implemented when a most upstream temperature T1 becomes a reference temperature T0 when a start temperature Tc is the reference temperature T0, in a case when the determination means 44 determines that the first oxidation catalyst 31 is not deteriorated, and implements the function recovery control when the most upstream temperature T1 becomes a temperature Td higher than the reference temperature T0, when the determination means 44 determines the deterioration of the first oxidation catalyst 31.SELECTED DRAWING: Figure 2 【課題】還元触媒の上流に捕集装置を介設せずに配置された酸化触媒が劣化した場合でも、還元触媒への熱害を防止すると共に燃費の悪化を回避しながら、後処理装置の機能を回復できる内燃機関及び排気ガス後処理装置の機能回復方法を提供する。【解決手段】第一酸化触媒３１の劣化を判定する判定手段４４を備え、制御装置４０を、判定手段４４で第一酸化触媒３１が劣化していないと判定した場合には、開始温度Ｔｃを基準温度Ｔ０とし、最上流温度Ｔ１が基準温度Ｔ０になったときに機能回復制御を行い、判定手段４４で第一酸化触媒３１が劣化していると判定した場合には、最上流温度Ｔ１が基準温度Ｔ０よりも高い温度Ｔｄになったときに機能回復制御を行うように構成される。【選択図】図２