Air-assist fuel injection system

An air-assisted electromagnetic fuel injection valve for an internal combustion engine, comprising a valve body having a fuel passage formed therein;

• a valve seat formed in said fuel passage;
• electromagnetic means including a ball valve moveable in an axial direction of the valve body in association with said valve seat for controlling the flow of liquid fuel along said fuel passage in accordance with an applied electrical signal;
• a fuel swirling element disposed along said fuel passage for swirling said liquid fuel in a first direction;
• and an air swirling element disposed in said fuel passage downstream of said fuel swirling element for swirling compressed air supplied thereto in a second direction opposite said first direction in an air swirling chamber disposed with respect to said fuel swirling element so that swirling liquid fuel is supplied into swirling compressed air in said air swirling chamber, whereby the swirling liquid fuel is divided into fine droplets to form a fuel spray, wherein said fuel swirling element has offset radial grooves through which liquid fuel is introduced into a fuel swirling chamber, said fuel swirling chamber having an opening through which swirling fuel is introduced to said air swirling element.

An air-assisted electromagnetic fuel injection valve for an internal combustion engine, comprising a valve body having a fuel passage formed therein;

• a valve seat formed in said fuel passage;
• electromagnetic means including a ball valve moveable in an axial direction of the valve body in association with said valve seat for controlling the flow of liquid fuel along said fuel passage in accordance with an applied electrical signal;
• a fuel swirling element disposed along said fuel passage for swirling said liquid fuel in a first direction;
• and an air swirling element disposed in said fuel passage downstream of said fuel swirling element for swirling compressed air supplied thereto in a second direction opposite said first direction in an air swirling chamber disposed with respect to said fuel swirling element so that swirling liquid fuel is supplied into swirling compressed air in said air swirling chamber, whereby the swirling liquid fuel is divided into fine droplets to form a fuel spray, wherein both of said fuel swirling element and said air swirling element are disk-like elements having central apertures along which said fuel passage extends.