| 摘要 |
<p>A hydraulic control valve has a valve body, a selectively energizable coil, and an armature positioned adjacent the coil. The coil is energizable to generate a magnetic force that moves the armature from a first position to a second position. A pole piece is positioned to establish a gap between the pole piece and the armature. The pole piece has a cavity that opens at the gap. A piston extends from the armature into the cavity and moves with the armature. The armature is biased to seat at a valve seat in the first position by pressurized fluid. Magnetic force required to move the armature away from the valve seat is a function of the difference between an area of the piston and an area defined by contact of the armature at the valve seat.</p> |
