In a conventional fuel injection valve, a movable valve body that constitutes a valve mechanism is constituted by an armature and a valve portion.  Further, a solenoid device is constituted by a resin bobbin, a coil wound around the bobbin, a metal core, a housing, and a lid-shaped cap.  Terminals serving as electrodes are connected to the coil. 
A pipe is disposed between the housing and the armature.  A valve seat, the movable valve body, a spring that pushes the movable valve body toward the valve seat side, the armature, and the core are inserted into the pipe.  The bobbin is mounted on an outer periphery of the pipe and housed in the housing.  The cap is welded to one axial direction end portion of the housing so as to cover the bobbin. 
The terminals, the pipe, the housing, and the cap are insert-molded in a connector mold.  An upper end portion of the pipe projects to the outside of the connector mold.  Further, a rubber ring (an O ring) is mounted on an outer periphery of the upper end portion of the pipe. 
An inner peripheral surface of the bobbin contacts an outer peripheral surface of the pipe entirely, with no gaps.  As a result, the bobbin is mounted on the pipe without play. 
When the valve is closed, the valve body is pressed against the valve seat by the spring.  When the terminals are energized from this condition, the solenoid device is excited such that the armature is attracted to the core side.  Accordingly, the movable valve body moves to the core side such that a gap is formed between the valve portion and the valve seat (i.e. such that the valve opens), and as a result, fuel flows through the gap (see PTL 1, for example).