Internal combustion engine exhaust gas purifier apparatus
AssigneeNippondenso Co., Ltd.
InventorsYukihiro Yamashita, Toshiki Matsumoto
Life of this patent
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Abstract
In order to activate an exhaust catalyst of an engine as quickly as possible from the engine restart, an exhaust damper for opening and closing an exhaust pipe is disposed downstream of a catalyst. A pneumatic actuator drives to open and close the exhaust damper. A negative pressure is introduced into a pressure chamber of the pneumatic actuator to close the exhaust damper after the engine is stopped. The closed exhaust damper keeps the warmth of the catalyst to ensure high exhaust gas purification performed when the engine is restarted. Alternatively, activation of the exhaust catalyst is enhanced by retarding the engine ignition timing and raising the engine idling speed.
Claims16
An internal combustion engine exhaust gas purifying apparatus comprising:
- exhaust closing means provided in an exhaust passage of an internal combustion engine having a catalyst for purifying exhaust gas, for opening and closing the exhaust passage;
- catalyst state detecting means for detecting a state of the catalyst;
- and
- drive means for closing the exhaust passage by using the exhaust closing means after the internal combustion engine has stopped, on the basis of the state of the catalyst detected by the catalyst state detecting means.
An internal combustion engine exhaust gas purifying apparatus comprising:
- catalyst early warm-up means for, after an internal combustion engine is started, performing catalyst early warm-up control to quickly increase temperature of a catalyst provided in an exhaust passage of the internal combustion engine;
- catalyst temperature detecting means for detecting temperature of the catalyst;
- and
- catalyst early warm-up deciding means for deciding whether to perform the catalyst early warm-up control by the catalyst early warm-up means on the basis of the temperature of the catalyst;
- wherein the catalyst early warm-up means calculates a parameter of the catalyst early warm-up control in accordance with the catalyst temperature detected by the catalyst temperature detecting means.
An internal combustion engine exhaust gas purifying apparatus comprising:
- catalyst early warm-up means for, after an internal combustion engine is started, performing catalyst early warm-up control to quickly increase temperature of a catalyst provided in an exhaust passage of the internal combustion engine;
- catalyst temperature detecting means for detecting temperature of the catalyst;
- and
- catalyst early warm-up deciding means for deciding whether to perform the catalyst early warm-up control by the catalyst early warm-up means on the basis of the temperature of the catalyst;
- wherein the catalyst temperature detecting means estimates a catalyst temperature on the basis of coolant temperature of the internal combustion engine and duration of stoppage of the internal combustion engine.
An internal combustion engine exhaust gas purifying apparatus comprising:
- catalyst early warm-up means for, after an internal combustion engine is started, performing catalyst early warm-up control to quickly increase temperature of a catalyst provided in an exhaust passage of the internal combustion engine;
- catalyst temperature detecting means for detecting temperature of the catalyst;
- and
- catalyst early warm-up deciding means for deciding whether to perform the catalyst early warm-up control by the catalyst early warm-up means on the basis of the temperature of the catalyst;
- wherein the catalyst temperature detecting means estimates a catalyst temperature on the basis of at least one of element temperature and heater temperature of an air-fuel ratio sensor disposed on at least one of upstream side and downstream side of the catalyst.
A method for purifying internal combustion engine exhaust gas, said method comprising:
- after an internal combustion engine is started, performing catalyst early warm-up control to quickly increase temperature of a catalyst provided in an exhaust passage of the internal combustion engine;
- detecting temperature of the catalyst;
- and
- determining whether to perform the catalyst early warm-up control based on the temperature of the catalyst;
- wherein the determining step includes calculating a parameter of the catalyst early warm-up control in accordance with the detected catalyst temperature.
A method for purifying internal combustion engine exhaust gas, said method comprising:
- after an internal combustion engine is started, performing catalyst early warm-up control to quickly increase temperature of a catalyst provided in an exhaust passage of the internal combustion engine;
- detecting temperature of the catalyst;
- and
- determining whether to perform the catalyst early warm-up control based on the temperature of the catalyst;
- wherein the detecting step includes estimating a catalyst temperature based on coolant temperature of the internal combustion engine and duration of engine stoppage.
A method for purifying internal combustion engine exhaust gas, said method comprising:
- after an internal combustion engine is started, performing catalyst early warm-up control to quickly increase temperature of a catalyst provided in an exhaust passage of the internal combustion engine;
- detecting temperature of the catalyst;
- and
- determining whether to perform the catalyst early warm-up control based on the temperature of the catalyst;
- wherein the detecting step includes estimating a catalyst temperature based on at least one of element temperature and heater temperature of an air-fuel ratio sensor disposed on at least one of an upstream side and downstream side of the catalyst.
A method for purifying internal combustion engine exhaust gas with a catalyst in an exhaust passage, said method comprising:
- detecting a state of the catalyst;
- and
- closing the exhaust passage after the internal combustion engine has stopped based on the detected state of the catalyst.
Dependencies are inferred from the claim text.