Patent ID: 8490888

Claim:
A fuel injection system of an internal combustion engine, including: a combustion chamber including a chamber ceiling and a chamber wall; and a fuel injector mountable with respect to the combustion chamber for delivering fuel thereto; the fuel injector including: a nozzle body having a primary nozzle axis (A-A); a first outlet opening having a first axis; a second outlet opening having a second axis; and means for controlling fuel delivery through the first and second outlet openings, said means including an inner valve needle and an outer valve needle, and being operable to permit fuel delivery from only the first outlet opening at relatively low engine loads and speeds, or through both the first and second outlet openings together at relatively high engine loads and speeds, the fuel injector including load transmitting means to permit the valve needle that controls fuel delivery from the first outlet opening to transmit a force to the valve needle that controls fuel delivery from the second outlet opening, so as to cause movement of the valve needle that controls fuel delivery from the second outlet opening when the valve needle that controls fuel delivery from the first outlet opening is moved beyond a predetermined amount; wherein the first and second outlet openings are oriented such that, in use, when fuel delivery is permitted through only said first outlet opening, a first spray formation is injected along the first axis, the first spray formation reaching a first target distance below said chamber ceiling at a radial distance from the primary nozzle axis; and when fuel delivery is permitted through both openings together, respective first and second spray formations are injected along the respective first and second axes to merge externally of the injector so as to give rise to a combined spray formation having a third axis, the combined spray formation reaching a second target distance below said chamber ceiling at said radial distance from the primary nozzle axis; wherein said first target distance is less than said second target distance.