Fluid-sealed, electromagnetic valve operating structure, particularly for combustion engine fuel injection system

Fluid-sealed, electromagnetic positioning device, particularly for use as an electromagnetic valve operator suitable in a fuel injection system of an internal combustion engine having

• a housing (1);
• a solenoid coil (2) positioned in the housing and formed with a central, tubular opening;
• a magnetic core element (34) having a portion extending across said opening;
• a magnetic armature (32) longitudinally movable in said opening;
• a sealing sleeve (30) extending into the tubular opening to seal the interior of the solenoid against fluid, the flow of which is to be controlled, and to guide the longitudinal movement of the armature,
• a closed bottom (31) formed on the sealing sleeve and positioned in close engagement with the inner face of the portion of the core (34) extending across said opening;
• and an abutment (22) formed on the armature (32), said abutment being positioned beyond the end of the sleeve (30), the length of the sleeve and the position of the abutment being matched with respect to the length of travel of the armature (32) upon energization of the solenoid coil (2) to provide for a gap between the abutment (22) and the end of the sleeve (30) and maintenance of a gap between the end of the armature and the portion (34) of the core extending across the opening which is determined by the thickness of the closed bottom (31) of the sleeve to prevent sticking of the armature to the core and damage to the end of the sleeve (30) facing said abutment (22).