摘要:
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15), an exhaust purification catalyst (13), and a particulate filter (14) are arranged. At the time of engine operation, the amplitude of change of the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to become within a predetermined range of amplitude by control of the injection amount of hydrocarbons from the hydrocarbon feed valve (15). When the temperature of the particulate filter (14) is to be raised to be regeneration temperature, the injection amount of hydrocarbons is increased and thereby the pass through amount of hydrocarbons which pass through the exhaust purification catalyst (13) is increased.
摘要:
An exhaust gas purifying apparatus for an internal combustion engine is provided with: a first catalyst (234) which is disposed in an exhaust passage of the internal combustion engine (200); a second catalyst (235) which is disposed in the exhaust passage on a downstream side of the first catalyst; a reducing agent supplying device (233) which is disposed on an upstream side of the first catalyst and which is configured to supply a reducing agent into the exhaust passage; and a reducing agent supply controlling device (100) which is configured to control the reducing agent supplying device such that an air-fuel ratio on the upstream side of the first catalyst becomes momentarily rich.
摘要:
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15), an exhaust purification catalyst (13), and a particulate filter (14) are arranged. At the time of engine operation, the amplitude of change of the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to become within a predetermined range of amplitude by control of the injection amount of hydrocarbons from the hydrocarbon feed valve (15). When the temperature of the particulate filter (14) is to be raised to be regeneration temperature, the injection amount of hydrocarbons is increased and thereby the pass through amount of hydrocarbons which pass through the exhaust purification catalyst (13) is increased.
摘要:
An exhaust gas purifying apparatus for an internal combustion engine is provided with: a first catalyst (234) which is disposed in an exhaust passage of the internal combustion engine (200); a second catalyst (235) which is disposed in the exhaust passage on a downstream side of the first catalyst; a reducing agent supplying device (233) which is disposed on an upstream side of the first catalyst and which is configured to supply a reducing agent into the exhaust passage; and a reducing agent supply controlling device (100) which is configured to control the reducing agent supplying device such that an air-fuel ratio on the upstream side of the first catalyst becomes momentarily rich.
摘要:
A three-way catalyst (20) having an oxygen storage function and an exhaust purification catalyst (22) are arranged in the exhaust passage of an internal combustion engine. During medium-load operation of the engine the degree of lean of the air-fuel ratio in the combustion chamber (5) is increased so as to increase the oxygen storage amount of the three-way catalyst (20) to the maximum oxygen storage amount, and the air-fuel ratio in the combustion chamber (5) even after the oxygen storage amount of the three-way catalyst (20) has reached the maximum oxygen, storage amount is maintained at lean, after which the air-fuel ratio is returned to rich, and at this time, as the amount of poisoning of a noble metal catalyst when the air-fuel ratio in the combustion chamber (5) is rich increases, the amount of time for which the air-fuel ratio in the combustion chamber (5) is maintained at lean is increased.
摘要:
An internal combustion engine wherein an exhaust purification catalyst and hydrocarbon feed valve are arranged in an engine exhaust passage and wherein the NOX which is contained in the exhaust gas is removed by injection of hydrocarbons from the hydrocarbon feed valve by a predetermined period. Hydrocarbons are injected from the hydrocarbon feed valve toward the upstream side of the engine exhaust passage. When hydrocarbons are injected from the hydrocarbon feed valve by a predetermined period, the injection pressure of the hydrocarbons is made to gradually fall from injection start to injection end in the injection time period of each injection.
摘要:
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. At the time of engine operation, the amplitude of change of the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to become within a predetermined range of amplitude by control of at least one of the injection time and injection pressure of hydrocarbons from the hydrocarbon feed valve (15). In this case, when only the injection time of hydrocarbons is controlled, the injection time of hydrocarbons under the same engine operating state is made longer the higher the temperature of the exhaust purification catalyst (13).
摘要:
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust treatment catalyst (13) are arranged. On a substrate (45) of the exhaust treatment catalyst (13), a coat layer comprised of at least two layers of a top coat layer (46) and a bottom coat layer (47) is formed. The top coat layer (46) is comprised of an exhaust purification catalyst for reacting NOx contained in exhaust gas and reformed hydrocarbons, while the bottom coat layer (47) is comprised of an NOx absorption catalyst. The concentration of hydrocarbons which flows into the exhaust treatment catalyst (13) is made to vibrate within a predetermined range of amplitude and within a predetermined range of period. Due to this, NOx contained in exhaust gas and NOx desorbed from the NOx absorption catalyst (47) are reduced in the exhaust purification catalyst (46).
摘要:
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. At the time of engine operation, the amplitude of change of the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to become within a predetermined range of amplitude by control of the injection amount of hydrocarbons from the hydrocarbon feed valve (15), the concentration of hydrocarbons flowing into the exhaust purification catalyst (13) is made to vibrate by a predetermined range of period by control of the injection period of hydrocarbons from the hydrocarbon feed valve (15), and thereby the NOx contained in the exhaust gas and the NOx stored in the exhaust purification catalyst (13) are reduced.
摘要:
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (17), exhaust purification catalyst (13), and intermediate NOx adsorption catalyst (15) are arranged. The intermediate NOx adsorption catalyst (15) adsorbs nitrogen-containing intermediate and NOx which are exhausted from the exhaust purification catalyst (13). To make the nitrogen-containing intermediate or NOx which is adsorbed at the intermediate NOx adsorption catalyst (15) desorb from it, the concentration of hydrocarbons flowing into the exhaust purification catalyst (13) is made to vibrate within a predetermined range of amplitude of 200 ppm or more and within a predetermined range of period of 5 seconds or less, whereby NOx which is contained in exhaust gas is removed at the exhaust purification catalyst (13) while the heat of oxidation reaction of the hydrocarbons is used to make the intermediate NOx adsorption catalyst (15) rise in temperature.