Internal combustion engine control system

Abstract

In an internal combustion engine control system for controlling an internal combustion engine, comprising a fuel injection control means for controlling fuel injection quantity to be injected by a fuel supply system for supplying fuel to the internal combustion engine, and fuel injection timing, and a variable valve control means for continuously or gradually varying at least opening timing, closing timing or lift of a intake valve or an exhaust valve for sealing up a combustion chamber of the internal combustion engine, the fuel injection control means controls at least fuel injection quantity or fuel injection timing on the basis of a value of a controlled variable provided by the variable valve control means. Since air quantity can be regulated by a variable valve timing mechanism, pumping loss and fuel consumption can be reduced. Fuel injected into the combustion chamber can be atomized by opening the intake valve so that a shock wave is generated in the combustion chamber and, consequently, stable combustion can be achieved without deteriorating the quality of the exhaust gas.

1 . An internal combustion engine control system for controlling an internal combustion engine, comprising: 
 a fuel injection control means for controlling fuel injection quantity to be injected by a fuel supply system for supplying fuel to the internal combustion engine, and fuel injection timing; and    a variable valve control means for continuously or gradually varying at least opening timing, closing timing or lift of a intake valve or an exhaust valve for sealing up a combustion chamber of the internal combustion engine;    wherein the fuel injection control means controls at least fuel injection quantity or fuel injection timing on the basis of a value of a controlled variable provided by the variable valve control means.    
     
     
         2 . The internal combustion engine control system according to  claim 1  further comprising a supercharger disposed in a intake passage of the internal combustion engine.  
     
     
         3 . The internal combustion engine control system according to  claim 2  further comprising a knocking sensing means for sensing or estimating the occurrence of knocking in the internal combustion engine, 
 wherein the variable valve control means controls at least valve opening timing, valve closing timing or valve lift of the intake valve continuously or gradually on the basis of the result of sensing action of the knocking sensing means to control the compression ratio of the internal combustion engine.  
 
     
     
         4 . The internal combustion engine control system according to  claim 1  further comprising a knocking sensing means for sensing or estimating the occurrence of knocking in the internal combustion engine, 
 wherein the variable valve control means controls at least valve opening timing, valve closing timing or valve lift of the intake valve continuously or gradually on the basis of the result of sensing action of the knocking sensing means to control the compression ratio of the internal combustion engine.  
 
     
     
         5 . The internal combustion engine control system according to  claim 1  further comprising a crank angle sensing means for sensing or estimating crank angles of the internal combustion engine, 
 wherein the variable valve control means opens the intake valve when a piston is at a position corresponding to a crank angle at which the volume of the combustion chamber of the internal combustion engine is not less than twice the volume of the combustion chamber of the same when the piston is at the top dead center.  
 
     
     
         6 . The internal combustion engine control system according to  claim 1  further comprising: 
 a crank angle sensing means for sensing or estimating crank angles of the internal combustion engine, and  
 a intake pipe pressure sensing means for sensing or estimating pressure in a intake pipe of the internal combustion engine;  
 wherein the variable valve control means controls intake valve opening timing on the basis of the results of sensing actions of the crank angle sensing means and the intake pipe pressure sensing means.  
 
     
     
         7 . The internal combustion engine control system according to  claim 1  further comprising a combustion chamber pressure sensing means for sensing or estimating pressure in the combustion chamber of the internal combustion engine; 
 wherein the variable valve control means opens the intake valve of the internal combustion engine when pressure in the combustion chamber is not higher than ½ times a pressure in the combustion chamber when the piston is at the top dead center.  
 
     
     
         8 . The internal combustion engine control system according to  claim 1 , wherein the internal combustion engine is provided with an accelerator pedal stepping-on measurement sensing means for sensing or estimating stepping-on measurement of an accelerator pedal, and 
 the variable valve control means sets the lift of the intake valve of the internal combustion engine at a fixed value when the accelerator pedal stepping-on measurement is not greater than a predetermined value, and the fuel injection control means controls fuel injection quantity to be injected into the internal combustion engine.    
     
     
         9 . The internal combustion engine control system according to  claim 1 , wherein the internal combustion engine is provided with an accelerator pedal stepping-on measurement sensing means for sensing or estimating stepping-on measurement of an accelerator pedal, and 
 the variable valve control means sets the lift of the intake valve of the internal combustion engine at a fixed value and sets intake valve opening period at a predetermined period when the accelerator pedal stepping-on measurement is not greater than a predetermined value, and controls air quantity to be sucked by the internal combustion engine by varying intake valve opening timing.    
     
     
         10 . The internal combustion engine control system according to  claim 1 , wherein the internal combustion engine is provided with a intake pipe pressure sensing means for sensing or estimating pressure in a intake pipe of the internal combustion engine, and 
 the variable valve control means closes the intake valve of the internal combustion engine when pressure in the intake pipe coincides with a predetermined value.    
     
     
         11 . The internal combustion engine control system according to  claim 1  further comprising a catalyst temperature sensing means for sensing or estimating temperature of a catalyst disposed in an exhaust passage of the internal combustion engine, 
 wherein when the temperature of the catalyst is not higher than a predetermined value, the variable valve control means opens the exhaust valve of the internal combustion engine at a time earlier than a time when the exhaust valve is opened if the temperature of the catalyst is higher than the predetermined value.  
 
     
     
         12 . The internal combustion engine control system according to  claim 1 , wherein the variable valve control means opens the intake valve of the internal combustion engine so that a shock wave is generated in the combustion chamber of the internal combustion engine.  
     
     
         13 . An internal combustion engine control system for controlling an internal combustion engine, comprising: 
 a fuel injection control means for controlling fuel injection quantity to be injected by a fuel injection system for directly injecting fuel into a combustion chamber of the internal combustion engine, and fuel injection timing; and    a variable valve control means for continuously or gradually varying at least opening timing, closing timing or lift of a intake valve or an exhaust valve for sealing up the combustion chamber of the internal combustion engine;    wherein the fuel injection control means controls at least fuel injection quantity or fuel injection timing on the basis of a value of a controlled variable provided by the variable valve control means.    
     
     
         14 . The internal combustion engine control system according to  claim 13  further comprising a supercharger disposed in a intake passage of the internal combustion engine.  
     
     
         15 . The internal combustion engine control system according to  claim 14  further comprising a knocking sensing means for sensing or estimating the occurrence of knocking in the internal combustion engine, 
 wherein the variable valve control means controls at least valve opening timing, valve closing timing or valve lift of the intake valve continuously or gradually on the basis of the result of sensing action of the knocking sensing means to control the compression ratio of the internal combustion engine.  
 
     
     
         16 . The internal combustion engine control system according to  claim 13  further comprising a knocking sensing means for sensing or estimating the occurrence of knocking in the internal combustion engine, 
 wherein the variable valve control means controls at least valve opening timing, valve closing timing or valve lift of the intake valve continuously or gradually on the basis of the result of sensing action of the knocking sensing means to control the compression ratio of the internal combustion engine.  
 
     
     
         17 . The internal combustion engine control system according to  claim 13  further comprising a crank angle sensing means for sensing or estimating crank angles of the internal combustion engine, 
 wherein the variable valve control means opens the intake valve when a piston is at a position corresponding to a crank angle at which the volume of the combustion chamber of the internal combustion engine is not less than twice the volume of the combustion chamber of the same when the piston is at the top dead center.  
 
     
     
         18 . The internal combustion engine control system according to  claim 13  further comprising: 
 a crank angle sensing means for sensing or estimating crank angles of the internal combustion engine, and  
 a intake pipe pressure sensing means for sensing or estimating pressure in a intake pipe of the internal combustion engine;  
 wherein the variable valve control means controls intake valve opening timing on the basis of the results of sensing actions of the crank angle sensing means and the intake pipe pressure sensing means.  
 
     
     
         19 . The internal combustion engine control system according to  claim 13  further comprising a combustion chamber pressure sensing means for sensing or estimating pressure in the combustion chamber of the internal combustion engine; 
 wherein the variable valve control means opens the intake valve of the internal combustion engine when pressure in the combustion chamber is not higher than ½ times a pressure in the combustion chamber when the piston is at the top dead center.  
 
     
     
         20 . The internal combustion engine control system according to  claim 13 , wherein the internal combustion engine is provided with an accelerator pedal stepping-on measurement sensing means for sensing or estimating stepping-on measurement of an accelerator pedal, and 
 the variable valve control means sets the lift of the intake valve of the internal combustion engine at a fixed value when the accelerator pedal stepping-on measurement is not greater than a predetermined value, and the fuel injection control means controls fuel injection quantity to be injected into the internal combustion engine.    
     
     
         21 . The internal combustion engine control system according to  claim 13 , wherein the internal combustion engine is provided with an accelerator pedal stepping-on measurement sensing means for sensing or estimating stepping-on measurement of an accelerator pedal, and 
 the variable valve control means sets the lift of the intake valve of the internal combustion engine at a fixed value and sets the intake valve opening period at a predetermined period when the accelerator pedal stepping-on measurement is not greater than a predetermined value, and controls air quantity to be sucked by the internal combustion engine by varying intake valve opening timing.    
     
     
         22 . The internal combustion engine control system according to  claim 13 , wherein the internal combustion engine is provided with a intake pipe pressure sensing means for sensing or estimating pressure in a intake pipe of the internal combustion engine, and 
 the variable valve control means closes the intake valve of the internal combustion engine when pressure in the intake pipe coincides with a predetermined value.    
     
     
         23 . The internal combustion engine control system according to  claim 13  further comprising a catalyst temperature sensing means for sensing or estimating temperature of a catalyst disposed in an exhaust passage of the internal combustion engine, 
 wherein when the temperature of the catalyst is not higher than a predetermined value, the variable valve control means opens the exhaust valve of the internal combustion engine at a time earlier than a time when the exhaust valve is opened if the temperature of the catalyst is higher than the predetermined value.