Intake air amount control apparatus and intake air amount control method for internal combustion engine

Abstract

A plurality of changing mechanisms change the manner in which intake air is supplied to an internal combustion engine. A control unit executes a cooperative control in which, based on the driving state of one of a variable vale lift mechanism and at least one of the other changing mechanisms other than the variable valve lift mechanism, the driving state of the other one of the variable valve lift mechanism and the at least one of the changing mechanisms is controlled. A determining unit determines whether the operational response of the changing mechanisms is decreased. A restricting unit restricts the cooperative control when the determining unit determines that the operational response of at least one of the changing mechanisms is decreased. Therefore, disadvantages caused by reduction in the operational response of the changing mechanisms are reduced.

1 . An intake air amount control apparatus for an internal combustion engine equipped with an intake valve, the apparatus comprising: 
 a plurality of changing mechanisms that change the manner in which intake air is supplied to the internal combustion engine, wherein the changing mechanisms include a variable valve lift mechanism, which changes the maximum lift of the intake valve;    a control unit, wherein the control unit executes a cooperative control in which, based on the driving state of one of the variable vale lift mechanism and at least one of the other changing mechanisms, the driving state of the other one of the variable valve lift mechanism and the at least one of the changing mechanisms is controlled;    a determining unit, which determines whether the operational response of the changing mechanisms is decreased; and    a restricting unit, which restricts the cooperative control when the determining unit determines that the operational response of at least one of the changing mechanisms is decreased.    
   
   
       2 . The control apparatus according to  claim 1 , wherein the changing mechanisms other than the variable valve lift mechanism include a variable valve timing mechanism, which changes the valve timing of the intake valve.  
   
   
       3 . The control apparatus according to  claim 1 , 
 wherein the driving state of the variable valve lift mechanism is controlled independently from the other changing mechanisms to restrict the cooperative control.    
   
   
       4 . The control apparatus according to  claim 3 , 
 wherein the restricting unit fixes a control target value of the maximum lift when controlling the driving state of the variable valve lift mechanism independently from the other changing mechanisms.    
   
   
       5 . The control apparatus according to  claim 4 , 
 wherein the restricting unit fixes the control target value to a value greater than the minimum value of the changeable range of the maximum lift.    
   
   
       6 . The control apparatus according to  claim 5 , 
 wherein the restricting unit fixes the control target value to the maximum value of the changeable range of the maximum lift.    
   
   
       7 . The control apparatus according to  claim 6 , wherein the maximum lift is fixed to the maximum value of the changeable range when the variable vale lift mechanism is deactivated.  
   
   
       8 . An intake air amount control method for an internal combustion engine equipped with an intake valve, the method comprising: 
 changing the manner in which intake air is supplied to the internal combustion engine using a plurality of changing mechanisms, wherein the changing mechanisms include a variable valve lift mechanism, which changes the maximum lift of the intake valve;    executing a cooperative control in which, based on the driving state of one of the variable vale lift mechanism and at least one of the other changing mechanisms, the driving state of the other one of the variable valve lift mechanism and the at least one of the changing mechanisms is controlled;    determining whether the operational response of the changing mechanisms is decreased; and    restricting the cooperative control when it is determined that the operational response of at least one of the changing mechanisms is decreased.    
   
   
       9 . The control method according to  claim 8 , further comprising: 
 controlling the driving state of the variable valve lift mechanism independently from the other changing mechanisms to restrict the cooperative control.    
   
   
       10 . The control method according to  claim 9 , further comprising: 
 fixing a control target value of the maximum lift when controlling the driving state of the variable valve lift mechanism independently from the other changing mechanisms.