US 11,655,786 B2
Fuel injector
Michael Hornby, Emerald Isle, NC (US)
Assigned to Stanadyne LLC, Jacksonville, NC (US)
Filed by Stanadyne LLC, Jacksonville, NC (US)
Filed on May 26, 2022, as Appl. No. 17/825,806.
Claims priority of provisional application 63/194,568, filed on May 28, 2021.
Prior Publication US 2022/0381212 A1, Dec. 1, 2022
Int. Cl. F02M 51/06 (2006.01); F02M 21/02 (2006.01); F02M 61/20 (2006.01)
CPC F02M 51/0667 (2013.01) [F02M 21/0263 (2013.01); F02M 61/20 (2013.01); F02M 2200/50 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A fuel injector for injecting fuel in a combustion engine, the fuel injector comprising:
a valve with a needle connected to a valve member and moveable along a longitudinal axis between an open and a closed position, to open and close the valve;
an actuator comprising an armature and a pole wherein the armature is axially moveable and coupled to the valve needle to move the valve needle toward the open position when the armature moves toward the pole, the armature having a first position axially spaced from the pole to define a first axial gap when the valve needle is the closed position and a second position in contact with the pole when the valve needle is in the open position, the armature coupled to the valve needle by a first armature stop between the armature and the valve member and a second armature stop between the armature and the pole, said first and second armature stops secured in fixed positions to the valve needle, the armature axially moveable relative to the valve needle between said first and second armature stops and biased toward said first armature stop by an armature spring between the armature and the second armature stop to define a second axial gap between the armature and the second armature stop when the valve is in the closed position, said armature defines an axial recess surrounding said valve needle and said armature spring is positioned in said axial recess and biased between a bottom of the axial recess and a lower surface of the second armature stop, said armature defines at least one fuel flow passage communicating between said axial recess and an area between the armature and the valve member, said axial recess includes an annular peripheral portion defined between an annular shoulder and an upper face of the armature, said second armature stop including a radially projecting flange extending radially beyond said annular shoulder and captured axially between the shoulder and the pole, said radially projecting flange including at least one opening allowing fluid communication from an area between the second armature stop and the pole and the axial recess;
a valve closing spring in contact with an upper surface of said second armature stop for biasing the valve needle away from the pole and toward the closed position;
wherein the at least one opening, axial recess and at least one fuel flow passage permit fluid communication from the area between the second armature stop and the pole to the area between the armature stop and the valve member, a bias of the valve closing spring is greater than a bias of the armature spring and movement of the armature toward the pole compresses the armature spring to close the second axial gap before the armature contacts the second armature stop to compress the return spring to move the valve needle toward the open position.