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US 6,644,021 B2Granted
Exhaust gas purifying apparatus of internal combustion engine
AssigneeMitsubishi Jidosha Kogyo Kabushiki Kaisha
InventorsKojiro Okada, Yasuki Tamura
Life of this patent
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Abstract
In an exhaust gas purifying apparatus of an internal combustion engine, the temperature of occlusion-type NOx catalyst is increased to emit SOx when the temperature of occlusion-type NOx catalyst is not less than a set temperature. This prevents the deterioration of fuel consumption and enables the regeneration of a catalyst device by efficiently desorbing a sulfur component from the catalyst device. In this case, the temperature of the occlusion-type NOx catalyst is preferably set according to the frequency of the SOx desorption, and the temperature of the occlusion-type NOx catalyst can be increased by, for example, retarding an ignition timing.
Claims12
An exhaust gas purifying apparatus of an internal combustion engine comprising:
- a catalyst device provided in an exhaust passage of said internal combustion engine, said catalyst device occluding a sulfur component in exhaust gas when an exhaust gas air-fuel ratio is lean at least;
- regenerating means for increasing a temperature of said catalyst device to desorb said sulfur component from said catalyst device when the temperature of said catalyst device is not less than a set temperature that is determined within such a range that the occluded sulfur component can be desorbed;
- frequency estimating means for estimating a frequency, representative of the normalized duration of sulfur regeneration time per unit distance traveled, at which the occluded sulfur component is brought into the state of being emitted;
- and
- operation control means for controlling an operation of said regeneration means according to an output of said frequency estimating means.
2 more elements
An exhaust gas purifying apparatus of an internal combustion engine comprising:
- a catalyst device provided in an exhaust passage of said internal combustion engine, said catalyst device occluding a sulfur component in exhaust gas when an exhaust gas air-fuel ratio is lean at least;
- regenerating means for increasing a temperature of said catalyst device to desorb said sulfur component from said catalyst device when the temperature of said catalyst device is not less than a set temperature that is determined within such a range that the occluded sulfur component can be desorbed;
- frequency estimating means for estimating a frequency at which the occluded sulfur component is brought into the state of being emitted;
- and
- operation control means for controlling an operation of said regeneration means according to an output of said frequency estimating means;
- wherein said frequency estimating means has desorption frequency sensing means for calculating said frequency according to a regeneration period and a running distance of said catalyst device at a specific catalyst temperature at which said sulfur component can be desorbed.
3 more elements
An exhaust gas purifying apparatus of an internal combustion engine comprising:
- a catalyst device provided in an exhaust passage of said internal combustion engine, said catalyst device occluding a sulfur component in exhaust gas when an exhaust gas air-fuel ratio is lean at least;
- regenerating means for increasing a temperature of said catalyst device to desorb said sulfur component from said catalyst device when the temperature of said catalyst device is not less than a set temperature that is determined within such a range that the occluded sulfur component can be desorbed;
- frequency estimating means for estimating a frequency at which the occluded sulfur component is brought into the state of being emitted;
- operation control means for controlling an operation of said regeneration means according to an output of said frequency estimating means;
- and
- set temperature changing means for changing said set temperature according to the output of said frequency estimating means;
- wherein said set temperature changing means increases said set temperature as said frequency increases.
4 more elements
An exhaust gas purifying apparatus of an internal combustion engine comprising:
- a catalyst device provided in an exhaust passage of said internal combustion engine, said catalyst device occluding a sulfur component in exhaust gas when an exhaust gas air-fuel ratio is lean at least;
- regenerating means for increasing a temperature of said catalyst device and making the air-fuel ratio rich to desorb said sulfur component from said catalyst device;
- frequency estimating means for estimating a frequency, representative of the normalized duration of sulfur regeneration time per unit distance traveled, at which the occluded sulfur component is brought into the state of being emitted;
- and
- operation control means for controlling an operation of said regeneration means according to an output of said frequency estimating means.
2 more elements
An exhaust gas purifying apparatus of an internal combustion engine comprising:
- a catalyst device provided in an exhaust passage of said internal combustion engine, said catalyst device occluding a sulfur component in exhaust gas when an exhaust gas air-fuel ratio is lean at least;
- regenerating means for increasing a temperature of said catalyst device and making the air-fuel ratio rich to desorb said sulfur component from said catalyst device;
- frequency estimating means for estimating a frequency, representative of sulfur regeneration time per unit distance traveled, at which the occluded sulfur component is brought into the state of being emitted;
- and
- operation control means for controlling an operation of said regeneration means according to an output of said frequency estimating means.
2 more elements
An exhaust gas purifying apparatus of an internal combustion engine comprising:
- a catalyst device provided in an exhaust passage of said internal combustion engine, said catalyst device occluding a sulfur component in exhaust gas when an exhaust gas air-fuel ratio is lean at least;
- regenerating means for increasing a temperature of said catalyst device to desorb said sulfur component from said catalyst device when the temperature of said catalyst device is not less than a set temperature that is determined within such a range that the occluded sulfur component can be desorbed;
- frequency estimating means for estimating a frequency, representative of sulfur regeneration time per unit distance traveled, at which the occluded sulfur component is brought into the state of being emitted;
- and
- operation control means for controlling an operation of said regeneration means according to an output of said frequency estimating means.
2 more elements
Dependencies are inferred from the claim text.