Patent ID: 6125803
Filing Date: 2000-10-03
Classification: F01L,H01F

Abstract:
An electromagnetically driven valve for an internal combustion engine, comprising:an armature coupled to a valve body of an exhaust valve of the engine for reciprocal movement therewith between an open position and a closed position;a first elastic member coupled to the armature to bias the armature toward the open position and a second elastic member coupled to the armature to bias the armature toward the closed position, wherein a neutral position of the armature is defined between the open and closed positions at a point where forces applied by the first and second elastic members balance one another; anda first core including a first coil therein and a second core including a second coil therein, wherein the first and second cores are disposed on opposite sides of the armature and are positioned so that, when the armature is in the neutral position, the first and second cores are spaced apart from the armature and wherein the first coil generates an electromagnetic force to attract the armature toward the open position;wherein one of the first core and the armature is provided with a first protrusion protruding a predetermined length toward the other of the first core and the armature thereby making a distance between the first core and the armature smaller than a distance between the second core and the armature when the armature is located in the neutral position and wherein the other of the first core and the armature is provided with a protrusion facing side that faces a side of the first protrusion which extends substantially parallel to the direction of armature movement when said armature is in the open position.