Fuel injector tip for control of fuel delivery

A fuel injector having an upper end and a lower end and a tip located at the lower end, the fuel injector and tip being located about a common longitudinal axis, comprising:

• a sac portion on the tip, the sac portion including:
• a sac chamber;
• an outer sac surface;
• and
• at least one nozzle passage extending from an inner end located in the sac chamber to an outer end located at the outer sac surface, the at least one nozzle passage being at an angle less than ninety degrees from the longitudinal axis at the lower end, the at least one nozzle passage extending along a central axis;
• an end surface located substantially adjacent to and parallel with the at least one nozzle passage and extending beyond the outer end of the at least one nozzle passage;
• and
• a curvilinear surface located on at least one of the end surface and the outer sac surface and configured such that a portion of fuel being injected through the at least one nozzle passage is directed to follow the curvilinear surface away from the central axis.

A method for injecting fuel into a cylinder of an engine, comprising the steps of:

• providing pressurized fuel to a sac chamber;
• delivering at least a portion of the fuel through at least one nozzle passage extending from an inner end located in the sac chamber to an outer end located at an outer sac surface;
• injecting the fuel from the outer end of the at least one nozzle passage into the cylinder along a direction of a central axis;
• and
• diverting a portion of the injected fuel to follow at least one curvilinear surface away from the central axis.