A liquid fuel injection nozzle unit includes a valve member which is loaded by a spring into contact with a seating and is movable away from said seating by the action of fuel under pressure. The head of the valve member is provided with groove means to promote swirling of the fuel downstream of the valve member as the valve member is opened. The groove means is so constructed that the effective cross sectional area of the grooves attains a maximum value before the valve member has moved to its fully opened position whereby the proportion of the total flow of fuel which flows through the groove means decreases as the valve member attains its fully opened position.
A fuel injection nozzle is provided with such an annular fuel passage that its fuel passage section is, at the earlier stage of fuel injection, maintained smaller than the whole sum of the sectional areas of injection orifices and adapted to increase gradually in response to the lift of a nozzle needle so that the rate of fuel injection increases gradually.
A fuel injection nozzle is provided with a valve seat having a valve opening in which a valve is slidably provided, and a seat portion on which the valve is seated, and a nozzle tip having a sack portion and an injection opening 36a formed on the sack portion. The valve seat is formed of metal, and at the same time, the nozzle tip is molded by metal injection molding, wherein the valve seat and nozzle tip are joined by welding, or after the injection opening of the nozzle tip is formed from the upstream side in the fuel injection direction by laser machining, the valve seat and nozzle tip are joined by welding.
A fuel injection nozzle for spraying a swirl of fuel, includes a nozzle body having a bore, an orifice communicated with the bore, and a wall defining the bore and the orifice. The bore for receiving an axially movable valve body has a first center axis and the orifice has a second center axis. An inlet open to the bore and an outlet open to outside the nozzle body. The wall includes a first circumferential edge portion defining the inlet of the orifice and a second circumferential edge portion defining the outlet of the orifice. A sprayed fuel body formed by fuel discharged from said orifice, has a third center axis. The first circumferential edge portion is so arranged as to allow the first center axis to be positioned inside the inlet. The second circumferential edge portion is so contoured as to allow at least a portion of the second circumferential edge portion to be out of a plane normal to the second center axis.
A method and apparatus for injecting fuel into a combustion chamber of an internal combustion engine particularly of two stroke cycle spark ignited engine, wherein a metered quantity of fuel is entrained in a gas, and the fuel and gas mixture so formed is delivered through a nozzle into the combustion chamber under conditions that will establish a fuel spray having a dispersion velocity in the direction of the spray axis of not more than 25 meters/sec at 35 millimeters of spray penetration from the nozzle when measured in still air atmospheric pressure, and preferably that dispersion velocity is not more than 18 meters/sec at 70 millimeters from the nozzle.
A nozzle for the injection of liquid fuel by compressed gas which produces a generally circular first array of gas-entrained fuel droplets and a second array of gas-entrained fuel droplets within the first array. The preferred nozzle has an outwardly opening poppet valve with notches (65) on the perimetal edge of the valve head (48). The division of the fuel-gas charge into two arrays reduces penetration of the charge into the combustion chamber with beneficial effect on combustion efficiency and exhaust emissions. Also disclosed is an arrangement in which an un-notched poppet valve co-operates with a notched valve port to similarly obtain division of the fuel-gas charge into two arrays.
