Patent ID: 6109025
Filing Date: 2000-08-29
Classification: B60K,B60W,F01N,F02B,F02D,F02M,Y02T,Y10S

Abstract:
A compression ignition type engine in which an amount of production of soot gradually increases and then peaks when an amount of inert gas in a combustion chamber increases and in which a further increase of the amount of inert gas in the combustion chamber results in a temperature of fuel and surrounding gas at the time of combustion in the combustion chamber becoming lower than a temperature of production of soot and therefore almost no production of soot any longer, said engine comprising:switching means for selectively switching between a first combustion where the amount of the inert gas in the combustion chamber is larger than the amount of inert gas where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of inert gas in the combustion chamber is smaller than the amount of inert gas where the amount of production of soot peaks;an NOx absorbent disposed in an exhaust passage of the engine and absorbing NOx when an air-fuel ratio of an exhaust gas flowing into the NOx absorbent is lean, said NOx absorbent releasing an absorbed NOx when the air-fuel ratio of the exhaust gas flowing into the NOx absorbent is rich or the stoichiometric air-fuel ratio; anddrive power generating means for generating drive power separately from a drive power of the engine, wherein, when NOx is to be released from the NOx absorbent when the second combustion is being performed, the second combustion is switched to the first combustion and the air-fuel ratio in the combustion chamber is made rich or the stoichiometric air-fuel ratio by reducing an amount of fuel supplied to the engine and the drive power generating means generates the drive power.