Linear solenoid actuator for an exhaust gas recirculation valve

摘要

A valve assembly (16) is disclosed for metering exhaust gas to the intake manifold (180) of an internal combustion engine (12). the valve assembly has a base (22) which includes a passage (44) communicating between the intake manifold and the exhaust manifold of the engine. The passage has a valve seat (52) which is operable with a valve member (94) to meter the flow of exhaust gas through the passage to the intake manifold. An actuator assembly (18) is mounted to the base and is operably connected to the valve member to move the valve member into and out of engagement with the valve seat. The actuator assembly includes a solenoid (116) having a magnetic circuit comprising stationary primary (118) and secondary (134) pole pieces and a movable armature (146). The primary pole piece includes a cylindrical tapered pole piece (120) and a tapered extension (162). The pole piece tapered outwardly with respect to the actuator axis and the extension tapered inwardly. A tapered armature portion (160) having an angle coinciding with the angle of the pole piece extension operates to focus leakage flux between the armature and the tapered pole piece while the armature and tapered extension provide force tailoring characteristics through an additional degree of design freedom available through the additional, and variable second air gap. $$