Solenoid actuator for a fuel injector

摘要

The actuator has a pole member 112, an armature 118 associated therewith, and an energizable winding 116 associated with the pole member. The solenoid actuator is iatchable by residual magnetism between the pole member and the armature without the aid of a permanent magnet. The pole member and the armature are composed of steel having a carbon content of between 0.8% and 1.2% by weight and an RC hardness of between 40 and 60. The armature is reciprocable between a first position in which the armature makes physical contact with the pole member and a second position in which the armature is spaced from the pole member. The armature occupies the first position when the winding is energized and the second position when the winding is deenergized. The armature is held in the first position by residual magnetism between the pole member and the armature when the winding is deenergized after being initially energized.