Exhaust gas purifying apparatus and method for internal combustion engine, and engine control unit

Abstract

An exhaust gas purifying apparatus and method for an internal combustion engine, and an engine control unit are provided for appropriately regenerating a filter by supplying neither too much nor too less intake air when the filter is regenerated by supplying an unburnt fuel into exhaust gases. A filter is disposed in the exhaust system for collecting particulate matters included in exhaust gases. An ECU instructs to burn particulate matters deposited in the filter to execute a regenerating operation for regenerating the filter. An intake throttle valve adjusts the amount of intake air flowing through an intake system of the internal combustion engine. The ECU controls the intake throttle valve to narrow down an opening of the intake throttle valve during execution of the regenerating operation by the regenerating operation executing means. The ECU also corrects the opening of the intake throttle valve in accordance with at least one of the temperature of the internal combustion engine, the atmospheric pressure, and the intake air temperature detected by at least one of sensors.

1 . An exhaust gas purifying apparatus for an internal combustion engine for purifying exhaust gases by collecting particulate matters included in the exhaust gases emitted from said internal combustion engine to an exhaust system, said exhaust gas purifying apparatus comprising: 
 a filter disposed in said exhaust system for collecting particulate matters included in exhaust gases;    regenerating operation executing means for burning particulate matters deposited in said filter to execute a regenerating operation for regenerating said filter;    an intake throttle valve for adjusting the amount of intake air flowing through an intake system of said internal combustion engine;    intake air control means for controlling said intake throttle valve to narrow down an opening of said intake throttle valve during execution of the regenerating operation by said regenerating operation executing means;    at least one of engine temperature detecting means for detecting a temperature of said internal combustion engine, atmospheric pressure detecting means for detecting the atmospheric pressure, and intake air temperature detecting means for detecting the temperature of intake are; and    correcting means for correcting the opening of said intake throttle valve in accordance with at least one of the temperature of said internal combustion engine, the atmospheric pressure, and the intake air temperature detected by at least one of said detecting means.    
   
   
       2 . An exhaust gas purifying apparatus for an internal combustion engine according to  claim 1 , wherein: 
 said at least one detecting means is said engine temperature detecting means,    wherein said correcting means corrects the opening of said intake throttle valve to be larger as the temperature of said internal combustion engine is lower.    
   
   
       3 . A method of purifying exhaust gases in an internal combustion engine by collecting particulate matters included in the exhaust gases emitted from said internal combustion engine to an exhaust system, said method comprising the steps of: 
 collecting particulate matters included in exhaust gases by a filter;    burning particulate matters deposited in said filter to execute a regenerating operation for regenerating said filter;    adjusting the amount of intake air flowing through an intake system of said internal combustion engine by an intake throttle valve;    narrowing down an opening of said intake throttle valve during execution of a regenerating operation;    detecting at least one of a temperature of said internal combustion engine, the atmospheric pressure, and the temperature of intake are; and    correcting the opening of said intake throttle valve in accordance with at least one of the temperature of said internal combustion engine, the atmospheric pressure, and the intake air temperature.    
   
   
       4 . A method of purifying exhaust gases in an internal combustion engine according to  claim 3 , wherein: 
 said step of detecting includes detecting the temperature of said internal combustion engine,    wherein said step of correcting includes correcting the opening of said intake throttle valve to be larger as the temperature of said internal combustion engine is lower.    
   
   
       5 . An engine control unit including a control program for purifying exhaust gases in an internal combustion engine by collecting particulate matters included in the exhaust gases emitted from the internal combustion engine to an exhaust system, said control program causing a computer to collect particulate matters included in exhaust gases by a filter; burn particulate matters deposited in said filter to execute a regenerating operation for regenerating said filter; adjust the amount of intake air flowing through an intake system of said internal combustion engine by an intake throttle valve; narrow down an opening of said intake throttle valve during execution of a regenerating operation; detect at least one of a temperature of said internal combustion engine, the atmospheric pressure, and the temperature of intake are; and correct the opening of said intake throttle valve in accordance with at least one of the temperature of said internal combustion engine, the atmospheric pressure, and the intake air temperature.  
   
   
       6 . An engine control unit according to  claim 5 , wherein said control program further causes the computer to detect the temperature of said internal combustion engine, and correct the opening of said intake throttle valve to be larger as the temperature of said internal combustion engine is lower.