Dual gap fuel injector

摘要

An electromagnetic fuel injector has an upper, middle and lower body. A solenoid and guide tube are mounted within the middle body. A plug is mounted within the guide tube. The armature moves from its lower position when the solenoid is not energized to its upper position. There are two air gaps which are closed when the armature moves to its upper position, one between the armature and a stop shoulder on the middle body and the other between the armature and the plug. During assembly, the plug is inserted partially into the guide tube. Next, the armature is inserted into the guide tube. The armature is pushed upward until it contacts a stop on the middle body. The armature and the plug then stop moving. Because the plug is in a tight fitting relationship with the upper body, it remains in place when the armature is moved back to its lower position. This positions the plug such that the two air gaps are equal. The second air gap is positioned between the top and bottom of the solenoid. A spring is positioned between an adjusting member and the armature. A flat disk spring is between a spacer and the lower body. The armature is located on one side of the spring and the pintle is located on the other side. The middle body, solenoid and armature are reversible and can be used in an outwardly or inwardly opening injector.