Method of affecting mixture formation and charge motion in an engine cylinder

Abstract

A method of affecting the mixture formation and motion of a charge in an engine cylinder during a suction cycle of a gas intake valve of the cylinder. The suction cycle has a first cycle portion and a subsequent, second cycle portion. The method includes the following steps: introducing air and fuel into the cylinder during the suction cycle; maintaining, during the first cycle portion, the gas intake valve in a first open position at full valve stroke in which the gas intake valve has a fully open cross-sectional flow passage area; and maintaining, during the second cycle portion, the intake valve in a second open position at a partial stroke of the gas intake valve. The partial stroke is less than one half of the full stroke; and in the second open position the gas intake valve has a partially open cross-sectional flow passage area.

1 . A method of affecting a mixture formation and motion of a charge in a cylinder of an externally ignited internal-combustion engine during a suction cycle of a gas intake valve of the cylinder; said suction cycle having a first cycle portion and a subsequent, second cycle portion; the method comprising the following steps: 
 (a) introducing air and fuel into the cylinder during said suction cycle;    (b) maintaining, during said first cycle portion, said gas intake valve in a first open position at full valve stroke in which said gas intake valve has a fully open cross-sectional flow passage area; and    (c) maintaining, during said second cycle portion, said gas intake valve in a second open position at a partial stroke of said gas intake valve; said partial stroke being less than one half of said full stroke; and in said second open position said gas intake valve having a partially open cross-sectional flow passage area.    
     
     
         2 . The method as defined in    claim 1   , wherein said step (c) comprises the step of directly moving said gas intake valve into said second open position from said first open position.  
     
     
         3 . The method as defined in    claim 1   , further comprising the step of fully closing said gas intake valve upon ending step (b) and before starting step (c).  
     
     
         4 . The method as defined in    claim 3   , further comprising the step of maintaining said gas intake valve closed for a period between steps (b) and (c).  
     
     
         5 . A method of affecting a mixture formation and motion of a charge in a cylinder of an externally ignited internal-combustion engine during a suction cycle of a gas intake valve of the cylinder; said suction cycle having a leading cycle portion, a trailing cycle portion and an intermediate cycle portion; the method comprising the following steps: 
 (a) introducing air and fuel into the cylinder during said suction cycle;    (b) maintaining, during said intermediate cycle portion, said gas intake valve in a first open position at full valve stroke in which said gas intake valve has a fully open cross-sectional flow passage area; and    (c) maintaining, during said leading and trailing cycle portions, said gas intake valve in a second open position at a partial stroke of said gas intake valve; each said partial stroke being less than one half of said full stroke; and in said second open position said gas intake valve having a partially open cross-sectional flow passage area.