| 摘要 |
PROBLEM TO BE SOLVED: To provide a valve assembly capable of obtaining an optimum force for an actuator. SOLUTION: An actuator assembly 18 capable of attaching and detaching a valve member to and from a valve seat 52 provided in a passage 44 of a valve assembly 16 communicating with an intake manifold 180 and an exhaust manifold of an engine 12 comprises a magnetic circuit having a stationary main magnetic pole piece 118, a second magnetic pole piece 134, and a movable armature 146. The main magnetic pole piece further comprises a tapered cylindrical magnetic pole part 120 and a tapered extension part 162. The cylindrical magnetic pole part and extension part are tapered outward and inward with respect to the axis of an actuator, respectively. The armature further comprises an armature part 160 tapered at the same angle as that of the extension part. These tapered cylindrical magnetic pole part, extension part, and armature part properly convert leak magnetic flux produced in the magnetic circuit between the magnetic pole piece and the armature so as to increase the force of the actuator. |
