An internal combustion engine wherein an HC treatment catalyst (12) having the function of adsorbing the HC in the exhaust gas is arranged upstream of the NOx selective reducing catalyst (14), an urea aqueous solution fed from the reducing agent feed valve (15) is arranged upstream of the HC treatment catalyst (12), urea, and NOx contained in the exhaust gas, and HC adsorbed on the HC treatment catalyst 12 are reacted with each other to form intermediate products having cyano groups, oximes, and amino groups, and these intermediate products are sent to the NOx selective reducing catalyst (14).

Exhaust purification device of internal combustion engine

In a spark ignition type internal combustion engine that includes a variable compression ratio mechanism A capable of changing the mechanical compression ratio, and a variable valve mechanism B capable of changing valve characteristics of an intake valve or an exhaust valve, the variable valve mechanism is mechanically coupled to the variable compression ratio mechanism, and the variable valve mechanism is controlled in accordance with the compression ratio-changing operation amount of the variable compression ratio mechanism. The variable valve mechanism is coupled to the variable compression ratio mechanism without intervention of an electronic control unit. Therefore, the possibility of the interference between a piston and an intake valve resulting from an abnormality in a control system that includes an electronic control unit as an intervening unit can be eliminated.

Spark ignition type internal combustion engine

An exhaust emission control device for an internal combustion engine, capable of supplying a just enough amount of reducing agent to a selective reduction catalyst even when a NOx purification ratio of the catalyst is changed by various causes, thereby enabling a high NOx purification ratio and very low exhaust emissions to be maintained. An ECU calculates a filtered value based on a signal from an exhaust gas concentration sensor, calculates a moving average value of a product of the filtered value and a reference input, calculates a control input such that the moving average value becomes equal to 0, and adds a reference input to the control input to calculate an FB injection amount. The ECU calculates an FF injection amount with a predetermined feedforward control algorithm, and adds the FF injection amount to the FB injection amount, to thereby calculate a urea injection amount.

Exhaust emission control device for internal combustion engine

A variable compression ratio internal combustion engine rotates a camshaft to cause relative movement between a crankcase and a cylinder block. The camshaft has a shaft member, a cam member fixed to the shaft member, and a movable bearing member rotatable with respect to the shaft member. The cam member is rotatably housed in a cam housing hole formed in the crankcase, and the movable bearing member is rotatably housed a bearing housing hole formed in the cylinder block. The length of a line segment joining the centers of the shaft member and the movable bearing member, the center of the movable bearing member being the center of rotation of the movable bearing member with respect to the bearing housing hole, is set to be longer than the length of a line segment joining the centers of the shaft member and the cam member, the center of the cam member being the center of rotation of the cam member with respect to the cam housing hole.

Variable compression ratio internal combustion engine

In an internal combustion engine, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged in an engine exhaust passage. A first NO X removal method which injects hydrocarbons from the hydrocarbon feed valve (15) within a predetermined range of period so that the reducing intermediate generated thereby reduces the NO X contained in the exhaust gas and a second NO X removal method which makes the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst (13) a first target rich air-fuel ratio by a period which is longer than this predetermined range are used. When the NO X removal method is switched from the second NO X removal method to the first NO X removal method, the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst (13) is made a second target air-fuel ratio which is smaller than the first target rich air-fuel ratio.

Exhaust purification system of internal combustion engine

PROBLEM TO BE SOLVED: To enhance a deterioration determination accuracy of a NOx occlusion catalyst. SOLUTION: This exhaust emission control device comprises: the NOx occlusion catalyst which occludes NOx when an air-fuel ratio of an inflow exhaust gas is lean, and which discharges the occluded NOx to perform reduction when the air-fuel ratio of the inflow exhaust gas is rich; a NOx amount calculation means for calculating a NOx amount occluded in the NOx occlusion catalyst based on an operating condition of the internal combustion engine; an air-fuel ratio control means for setting the air-fuel ratio to be rich when the NOx amount calculated by the NOx amount calculation means reaches a target occlusion amount; a target CO amount calculation means for calculating a CO amount required for reducing the NOx of the target occlusion amount; a used CO amount calculation means for calculating the CO amount actually used in the reduction of the NOx discharged from the NOx occlusion catalyst based on a detection result of an oxygen concentration detection means at a downstream side of the NOx occlusion catalyst; and a NOx occlusion catalyst deterioration determining means for determining deterioration of the NOx occlusion catalyst based on a deviation between the target CO amount and the used CO amount. COPYRIGHT: (C)2005,JPO&NCIPI

Hirano Takuo

Papers

Exhaust emission control device of internal combustion engine