摘要 |
An automotive emission control valve, such as an EGR valve, has a solenoid for operating a valve element. The solenoid has a stator and an armature. A pole piece of the stator is cooperatively associated with a wall of the armature and comprises a channel that is annular about, and concentric with, a centerline of armature motion. In radial cross section the channel is defined by radially inner and outer walls that form an open throat for the channel, allowing an end portion of the armature wall to move within the channel as the armature is displaced along the centerline. Various constructions for the inner and outer walls are disclosed, including tapers for both walls. <IMAGE> |