FUEL INJECTION NOZZLE HAVING A VARIABLE NOZZLE HOLE AREA

摘要

A nozzle for injecting fuel into a internal combustion engine, more particularly to a fuel injection nozzle having a hole and a rotary valve at the leading end of a nozzle body to control the rotation angle of the valve so as to vary the nozzle hole area, wherein the surrounding wall defining the hole has a control surface, and the rotary valve has a surface for receiving the pressure of pressurized fuel at its upper end, a conical surface having an angle corresponding to the inclined angle of the conical surface of the hole on its outer circumference, and a plurality of fuel passages provided therein at certain intervals in a circumferential direction that are open to the pressure receiving surface at one end thereof, each fuel passage being made open to a position of the conical surface corresponding to the nozzle hole on the side of the hole. This allows the fuel injection pressure to generate between the rotary valve and the nozzle body a friction torque greater that a torque rotating the rotary valve so that the rotary valve can be fixed to any position only by the fuel injection pressure.