Fuel injector having a cooled lower nozzle body

A fuel injector for injecting pressurized fuel into a combustion chamber of an internal combustion engine, the injector comprising:

• a nozzle housing including a nozzle bore extending along a longitudinal axis thereof;
• and
• a nozzle valve element disposed within said nozzle bore, said nozzle valve element having a longitudinal passage extending along a length of said nozzle valve element, said longitudinal passage including an outer end for discharging a flow of cooling fluid and an inner end for receiving a flow of cooling fluid, said nozzle valve element further including at least one transverse passage located adjacent said inner end of said longitudinal passage and extending transversely between said longitudinal passage and said nozzle bore, wherein a quantity of cooling medium flows into the nozzle bore, through said transverse passage, into said longitudinal passage, and along said longitudinal passage at least when said nozzle valve element is in a closed position within said nozzle bore to cool said nozzle valve element;
• wherein said nozzle housing includes at least one spray hole and said longitudinal passage has a diameter which is approximately 2.5 times a diameter of the at least one spray hole.

A fuel injector for injecting pressurized fuel into a combustion chamber of an internal combustion engine, the injector comprising:

• a nozzle housing including a nozzle bore extending along a longitudinal axis thereof;
• and
• a nozzle valve element disposed within said nozzle bore, said nozzle valve element having a longitudinal passage extending along a length of said nozzle valve element, said longitudinal passage including an outer end for discharging a flow of cooling fluid and an inner end for receiving a flow of cooling fluid, said nozzle valve element further including at least one transverse passage located adjacent said inner end of said longitudinal passage and extending transversely between said longitudinal passage and said nozzle bore, wherein a quantity of cooling medium flows into the nozzle bore, through said transverse passage, into said longitudinal passage, and along said longitudinal passage at least when said nozzle valve element is in a closed position within said nozzle bore to cool said nozzle valve element;
• wherein said nozzle housing includes at least one spray hole and said transverse passage has a diameter approximately equal to the diameter of the at least one spray hole.

A fuel injector, comprising:

• a nozzle housing having an outer peripheral surface and a nozzle cavity;
• a nozzle valve element disposed within said nozzle cavity;
• an annular passage surrounding said nozzle housing adjacent said outer peripheral surface, said annular passage in communication with said nozzle cavity and a drain;
• orifice means formed in said nozzle housing for connecting said nozzle cavity and said annular passage to provide a flow of cooling medium from the nozzle cavity through the orifice means, into said annular passage, for delivery to drain at least when said nozzle valve element is in a closed position within said nozzle cavity, thereby cooling said nozzle valve element;
• and
• a seal adapted to prevent leakage of said cooling fluid from said annular passage into the combustion chamber.

A fuel injector, comprising;

• a nozzle housing having an outer peripheral surface and a nozzle cavity;
• a nozzle valve element disposed within said nozzle cavity:
• an annular passage surrounding said nozzle housing adjacent said outer peripheral surface, said annular passage in communication with said nozzle cavity and a drain;
• orifice means formed in said nozzle housing for connecting said nozzle cavity and said annular passage to provide a flow of cooling medium from the nozzle cavity, through the orifice means, into said annular passage, for delivery to drain at least when said nozzle valve element is in a closed position within said nozzle cavity, thereby cooling said nozzle valve element;
• and
• a sleeve disposed over said nozzle housing, said annular passage being formed between said sleeve and nozzle housing.

A fuel injector, comprising:

• a nozzle housing having an outer peripheral surface and a nozzle cavity;
• a nozzle valve element disposed within said nozzle cavity;
• an annular passage surrounding said nozzle housing adjacent said outer peripheral surface, said annular passage in communication with said nozzle cavity and a drain;
• and
• orifice means formed in said nozzle housing for connecting said nozzle cavity and said annular passage to provide a flow of cooling medium from the nozzle cavity through the orifice means, into said annular passage, for delivery to drain at least when said nozzle valve element is in a closed position within said nozzle cavity, thereby cooling said nozzle valve element;
• wherein said orifice means comprises at least one orifice disposed within said nozzle housing and connecting said nozzle cavity and said annular passage, said nozzle housing including at least one spray hole, and said at least one orifice has a diameter approximately equal to the diameter of the at least one spray hole.