Patent ID: 7124959

Claim:
A dual fuel injection valve operable to independently and separately inject two different fuels into a combustion chamber of an internal combustion engine, said dual fuel injection valve comprising: (a) an injection valve body comprising: a first-fuel inlet port through which a first fuel can be introduced at injection pressure into said injection valve body; a first-fuel passage provided within said injection valve body and extending between said first-fuel inlet port and a first-fuel cavity; a second-fuel inlet port through which a second fuel can be introduced into said injection valve body; a second-fuel passage connecting said second-fuel inlet port to a second-fuel cavity; at least one first-fuel ejection port provided in said injection valve body through which said first fuel can be ejected directly into said combustion chamber from said first-fuel cavity; (b) a dual needle assembly comprising: a hollow outer needle with an open end, wherein said outer needle is movable within said injection valve body between a closed position when a first sealing surface associated with said outer needle is urged against a first seat associated with said injection valve body near said first-fuel ejection port thereby preventing said first fuel from flowing through said first-fuel ejection port, and an open position when said first sealing surface is spaced apart from said first seat thereby allowing said first fuel to flow through said first-fuel ejection port; at least one second-fuel ejection port provided in said outer needle through which said second-fuel can be ejected directly into said combustion chamber from said second-fuel cavity; an inner valve body comprising: said outer needle; and a cap associated with said open end of said outer needle; an inner needle disposed within said inner valve body, wherein said inner needle is movable within said inner valve body between a closed position when a second sealing surface associated with said inner needle is urged against a second seat associated with said outer needle thereby preventing said second fuel from flowing through said second-fuel ejection port, and an open position when said second sealing surface is spaced apart from said second seat, said cap providing a surface facing said inner needle that limits the range of movement for opening said inner needle; and an inner spring disposed within said inner valve body between said cap and said inner needle which contributes to biasing said inner needle in said closed position; (c) a first actuator assembly operable to selectively move said inner needle between said open and closed positions; and (d) a second actuator assembly operable to selectively move said outer needle between said open and closed positions.