초록 ▼

A device for purifying the exhaust gas of an internal combustion engine is disclosed. The device has a particulate filter arranged in the exhaust system on which the trapped particulates are oxidized, and a reversing mechanism for reversing the exhaust gas upstream side and the exhaust gas downstrea

A device for purifying the exhaust gas of an internal combustion engine is disclosed. The device has a particulate filter arranged in the exhaust system on which the trapped particulates are oxidized, and a reversing mechanism for reversing the exhaust gas upstream side and the exhaust gas downstream side of the particulate filter. The particulate filter has a trapping wall. The trapping wall has a first trapping surface and a second trapping surface. The reversing mechanism reverses the exhaust gas upstream side and the exhaust gas downstream side of the particulate filter so that the first trapping surface and the second trapping surface are used alternately to trap the particulates. The device can improve the amount of particulates that can be oxidized and removed on the particulate filter.

대표청구항 ▼

A device for purifying the exhaust gas of an internal combustion engine is disclosed. The device has a particulate filter arranged in the exhaust system on which the trapped particulates are oxidized, and a reversing mechanism for reversing the exhaust gas upstream side and the exhaust gas downstrea

A device for purifying the exhaust gas of an internal combustion engine is disclosed. The device has a particulate filter arranged in the exhaust system on which the trapped particulates are oxidized, and a reversing mechanism for reversing the exhaust gas upstream side and the exhaust gas downstream side of the particulate filter. The particulate filter has a trapping wall. The trapping wall has a first trapping surface and a second trapping surface. The reversing mechanism reverses the exhaust gas upstream side and the exhaust gas downstream side of the particulate filter so that the first trapping surface and the second trapping surface are used alternately to trap the particulates. The device can improve the amount of particulates that can be oxidized and removed on the particulate filter. he engine based on the computed oxygen storage amount so that the oxygen storage amount of the first catalyst is a target value. 8. An exhaust purification device as defined in claim 7, further comprising a second rear sensor which detects the characteristics of the exhaust flowing out of the second catalyst. 9. An exhaust purification device for an engine, comprising: a first catalyst provided in an exhaust passage of the engine, means for detecting the characteristics of the exhaust flowing into the first catalyst, means for determining whether the engine starts up from a warmed-up state when the engine starts, means for controlling the air-fuel ratio of the engine to rich until the exhaust flowing out from the first catalyst has become rich when it is determined that the engine starts up from the warmed-up state, means for computing the oxygen storage amount of the first catalyst based on the characteristics of the exhaust flowing into the first catalyst, and means for controlling the air-fuel ratio of the engine based on the computed oxygen storage amount so that the oxygen storage amount of the first catalyst is a target value. 10. An exhaust purification device for an engine, comprising: a first catalyst provided in an exhaust passage of the engine, a second catalyst provided downstream of the first catalyst, means for detecting the characteristics of the exhaust flowing into the first catalyst, means for determining whether the engine starts up from a warmed-up state when the engine starts, means for controlling the air-fuel ratio of the engine to rich until the exhaust flowing out from the second catalyst has become rich when it is determined that the engine starts from the warmed-up state, means for computing the oxygen storage amount of the first catalyst based on the characteristics of the exhaust flowing into the first catalyst, and means for controlling the air-fuel ratio of the engine based on the computed oxygen storage amount so that the oxygen storage amount of the first catalyst is a target value. 11. A method for controlling an air-fuel ratio of an engine which has a first catalyst in an exhaust passage of the engine, comprising: determining whether the engine starts up from a warmed-up state when the engine starts, controlling the air-fuel ratio of the engine to rich until the exhaust flowing out from the first catalyst has become rich when it is determined that the engine starts up from the warmed-up state, computing the oxygen storage amount of the first catalyst based on the characteristics of the exhaust flowing into the first catalyst, and controlling the air-fuel ratio of the engine based on the computed oxygen storage amount so that the oxygen storage amount of the first catalyst is a target value.