Control apparatus for internal combustion engine

Abstract

An engine ECU executes a program including the step of detecting engine start, the step of detecting, when rapid catalyst warm-up is necessary, the temperature of the engine coolant THW, the step of estimating, when the THW is lower than a predetermined threshold value, the amount of fuel sticking to the wall surface of an intake port and calculating a cold-state increase correction value Q (P) for an intake manifold injector, the step of changing the DI ratio r to satisfy the cold-state increase correction value Q (P), and the step of performing the rapid catalyst warm-up.

1 . A control apparatus for an internal combustion engine including a first fuel injection mechanism injecting fuel into a cylinder, a second fuel injection mechanism injecting fuel into an intake manifold, and an ignition device, said internal combustion engine having an exhaust system provided with a catalyst that is used for cleaning exhaust and that is activated at a temperature of at least a predetermined temperature, said control apparatus comprising: 
 a detection unit detecting a request to warm up said catalyst;    a control unit controlling said first and second fuel injection mechanisms, based on conditions required of said internal combustion engine, such that said first and second fuel injection mechanisms partake in fuel injection;    an ignition control unit controlling said ignition device; and    a temperature detector detecting the temperature of said internal combustion engine, wherein    said control unit controls said first and second fuel injection mechanisms, considering the temperature of said internal combustion engine, such that the ratio of fuel injection by said first fuel injection mechanism is at least equal to the ratio of fuel injection by said second fuel injection mechanism under the conditions that said first and second fuel injection mechanisms partake in the fuel injection and said request to warm up is detected, and    said ignition control unit controls said ignition device to retard ignition timing when said request to warm up is detected.    
   
   
       2 . The control apparatus for an internal combustion engine according to  claim 1 , said control apparatus further comprising a calculation unit calculating, based on the temperature of said internal combustion engine, an amount of wall-sticking fuel that is an amount of fuel injected by said second fuel injection mechanism into said intake manifold and sticking to a wall surface, wherein 
 said control unit controls, considering said amount of wall-sticking fuel, said first and second fuel injection mechanisms.    
   
   
       3 . The control apparatus for an internal combustion engine according to  claim 2 , wherein 
 said control unit changes, considering said amount of wall-sticking fuel, the ratio of fuel injection between said first fuel injection mechanism and said second fuel injection mechanism by increasing the ratio of fuel injection by said second fuel injection mechanism.    
   
   
       4 . The control apparatus for an internal combustion engine according to  claim 2 , wherein 
 said control unit changes the ratio of fuel injection between said first fuel injection mechanism and said second fuel injection mechanism by making an increase correction to the quantity of injected fuel injected by said second fuel injection mechanism according to said amount of wall-sticking fuel and increasing the ratio of fuel injection by said second fuel injection mechanism.    
   
   
       5 . The control apparatus for an internal combustion engine according to  claim 4 , said control apparatus further comprising a decrease unit attenuating, based on the temperature of said internal combustion engine, the quantity of injected fuel which is injected by said second fuel injection mechanism and to which said increase correction is made.  
   
   
       6 . The control apparatus for an internal combustion engine according to  claim 5 , wherein 
 said decrease unit more sharply attenuates the quantity of injected fuel to which said increase correction is made, as the temperature of said internal combustion engine is higher.    
   
   
       7 . The control apparatus for an internal combustion engine according to  claim 5 , wherein 
 said decrease unit more slowly attenuates the quantity of injected fuel to which said increase correction is made, as the temperature of said internal combustion engine is lower.    
   
   
       8 . The control apparatus for an internal combustion engine according to  claim 5 , wherein 
 said decrease unit decreases, from the quantity of injected fuel injected by said second fuel injection mechanism, the quantity of fuel corresponding to said increase correction.    
   
   
       9 . The control apparatus for an internal combustion engine according to  claim 5 , wherein 
 said decrease unit decreases, from the quantity of injected fuel injected by said first fuel injection mechanism and from the quantity of injected fuel injected by said second fuel injection mechanism, the quantity of fuel corresponding to said increase correction.    
   
   
       10 . The control apparatus for an internal combustion engine according to  claim 5 , wherein 
 said decrease unit decreases the quantity of fuel corresponding to said increase correction, such that the ratio of fuel injection between said first fuel injection mechanism and said second fuel injection mechanism before said increase correction is made is maintained.    
   
   
       11 . The control apparatus for an internal combustion engine according to  claim 5 , wherein 
 said decrease unit decreases the quantity of fuel corresponding to said increase correction, such that the ratio of fuel injection between said first fuel injection mechanism and said second fuel injection mechanism after said increase correction is made is maintained.    
   
   
       12 . The control apparatus for an internal combustion engine according to  claim 2 , wherein 
 said control unit controls said first and second fuel injection mechanisms such that the sum of the quantity of injected fuel injected by said first fuel injection mechanism and the quantity of injected fuel injected by said second fuel injection mechanism in the case where said amount of wall-sticking fuel is considered is smaller than that in the case where said amount of wall-sticking fuel is not considered.    
   
   
       13 . The control apparatus for an internal combustion engine according to  claim 1 , wherein 
 said first fuel injection mechanism is an in-cylinder injector and said second fuel injection mechanism is an intake manifold injector.    
   
   
       14 . A control apparatus for an internal combustion engine including first fuel injection means for injecting fuel into a cylinder, second fuel injection means for injecting fuel into an intake manifold, and an ignition device, said internal combustion engine having an exhaust system provided with a catalyst that is used for cleaning exhaust and that is activated at a temperature of at least a predetermined temperature, said control apparatus comprising: 
 detection means for detecting a request to warm up said catalyst;    control means for controlling said first and second fuel injection means, based on conditions required of said internal combustion engine, such that said first and second fuel injection means partake in fuel injection;    ignition control means for controlling said ignition device; and    temperature detection means for detecting the temperature of said internal combustion engine, wherein    said control means includes means for controlling said first and second fuel injection means, considering the temperature of said internal combustion engine, such that the ratio of fuel injection by said first fuel injection means is at least equal to the ratio of fuel injection by said second fuel injection means under the conditions that said first and second fuel injection means partake in the fuel injection and said request to warm up is detected, and    said ignition control means includes means for controlling said ignition device to retard ignition timing when said request to warm up is detected.    
   
   
       15 . The control apparatus for an internal combustion engine according to  claim 14 , said control apparatus further comprising calculation means for calculating, based on the temperature of said internal combustion engine, an amount of wall-sticking fuel that is an amount of fuel injected by said second fuel injection means into said intake manifold and sticking to a wall surface, wherein 
 said control means includes means for controlling, considering said amount of wall-sticking fuel, said first and second fuel injection means.    
   
   
       16 . The control apparatus for an internal combustion engine according to  claim 15 , wherein 
 said control means includes means for changing, considering said amount of wall-sticking fuel, the ratio of fuel injection between said first fuel injection means and said second fuel injection means by increasing the ratio of fuel injection by said second fuel injection means.    
   
   
       17 . The control apparatus for an internal combustion engine according to  claim 15 , wherein 
 said control means includes means for changing the ratio of fuel injection between said first fuel injection means and said second fuel injection means by making an increase correction to the quantity of injected fuel injected by said second fuel injection means according to said amount of wall-sticking fuel and increasing the ratio of fuel injection by said second fuel injection means.    
   
   
       18 . The control apparatus for an internal combustion engine according to  claim 17 , said control apparatus further comprising decrease means for attenuating, based on the temperature of said internal combustion engine, the quantity of injected fuel which is injected by said second fuel injection means and to which said increase correction is made.  
   
   
       19 . The control apparatus for an internal combustion engine according to  claim 18 , wherein 
 said decrease means includes means for more sharply attenuating the quantity of injected fuel to which said increase correction is made, as the temperature of said internal combustion engine is higher.    
   
   
       20 . The control apparatus for an internal combustion engine according to  claim 18 , wherein 
 said decrease means includes means for more slowly attenuating the quantity of injected fuel to which said increase correction is made, as the temperature of said internal combustion engine is lower.    
   
   
       21 . The control apparatus for an internal combustion engine according to  claim 18 , wherein 
 said decrease means includes means for decreasing, from the quantity of injected fuel injected by said second fuel injection means, the quantity of fuel corresponding to said increase correction.    
   
   
       22 . The control apparatus for an internal combustion engine according to  claim 18 , wherein 
 said decrease means includes means for decreasing, from the quantity of injected fuel injected by said first fuel injection means and from the quantity of injected fuel injected by said second fuel injection means, the quantity of fuel corresponding to said increase correction.    
   
   
       23 . The control apparatus for an internal combustion engine according to  claim 18 , wherein 
 said decrease means includes means for decreasing the quantity of fuel corresponding to said increase correction, such that the ratio of fuel injection between said first fuel injection means and said second fuel injection means before said increase correction is made is maintained.    
   
   
       24 . The control apparatus for an internal combustion engine according to  claim 18 , wherein 
 said decrease means includes means for decreasing the quantity of fuel corresponding to said increase correction, such that the ratio of fuel injection between said first fuel injection means and said second fuel injection means after said increase correction is made is maintained.    
   
   
       25 . The control apparatus for an internal combustion engine according to  claim 15 , wherein 
 said control means includes means for controlling said first and second fuel injection means such that the sum of the quantity of injected fuel injected by said first fuel injection means and the quantity of injected fuel injected by said second fuel injection means in the case where said amount of wall-sticking fuel is considered is smaller than that in the case where said amount of wall-sticking fuel is not considered.    
   
   
       26 . The control apparatus for an internal combustion engine according to  claim 14 , wherein 
 said first fuel injection means is an in-cylinder injector and said second fuel injection means is an intake manifold injector.