Patent ID: 7441746

Claim:
An injection valve comprising: a housing that defines a fluid passage therein, the housing having a valve seat; a needle that is provided in the housing, the needle blocking the fluid passage when the needle is seated to the valve seat, the needle communicating the fluid passage when the needle is lifted from the valve seat; a movable core that is provided in the housing, the movable core being axially movable together with the needle; and a stationary core that is fixed in the housing, the stationary core forming a magnetic circuit together with the movable core, wherein at least one of the movable core and the stationary core has an end that has a first protrusion protruding toward an end of an other of the movable core and the stationary core, the first protrusion is in a substantially annular shape, the first protrusion has a first protruding end that is adapted to making contact with the other of the movable core and the stationary core, at least one of the movable core and the stationary core has an end that has a second protrusion protruding toward an end of an other of the movable core and the stationary core, the second protrusion is in a substantially annular shape, the first protrusion is substantially coaxial with respect to the second protrusions, the first protrusion protrudes by a first protruding height, the second protrusion protrudes by a second protruding height, and the second protruding height is less than the first protruding height, the second protrusion and the end of the other of the movable core and the stationary core define a gap therebetween in a condition in which the first protrusion makes contact with the end of the other of the movable core and the stationary core, and the first protruding end is in parallel with a surface of the end of the other of the movable core and the stationary core wherein one of the movable core and the stationary core has both the first protrusion and the second protrusion, and the first protrusion and the second protrusion define an annular groove therebetween.