Patent ID: 8382007

Claim:
A fuel injection valve having a first end and a second end axially spaced from each other, comprising: a valve mechanism disposed on the first end, the valve mechanism including a nozzle defining an injection hole for injecting fuel and a needle for opening or closing the injection hole; a control chamber in which high-pressure fuel is introduced; and an electromagnetic valve that opens or closes a discharge passage for discharging fuel in the control chamber to a low pressure part, the electromagnetic valve being capable of changing pressure in the control chamber to actuate the needle, wherein the electromagnetic valve includes: a solenoid that defines a solenoid passage for providing a part of the discharge passage and generates electromagnetic force when being energized; a connector that receives a terminal connected to the solenoid; a housing that is disposed between the solenoid and the second end, defines a hole for providing a part of the discharge passage, and provides a shoulder end on which the connector is attached and which radially extends perpendicular to an axial direction of the fuel injection valve; an armature that is arranged in the discharge passage and attracted by the electromagnetic force of the solenoid; a movable member that moves with the armature to open or close the discharge passage; and a spring that urges the armature and the movable member in a direction to close the discharge passage, the hole providing the discharge passage in the housing includes: a first hole in which the spring is arranged; and a second hole located downstream of the first hole, the discharge passage is partially provided by a narrow part that is disposed to communicate between the first hole and the second hole through a narrow passage smaller in diameter than the first hole and the second hole, and the narrow passage of the narrow part has a diameter D perpendicular to a flow direction and a length L along the flow direction, and defines a ratio L/D equal to or smaller than 4.5.