| 摘要 |
Improvements in an armature-pintle assembly (36) and related stator structure (56, 58) of a solenoid actuator used in an EGR valve (10) for controlling the EGR valve opening in accordance with an electric control current from an engine control system. The stator structure defines an air gap (80) disposed in proximate surrounding relationship to a cylindrical tubular walled portion (126) of the armature (40). The air gap is defined by two confronting, but axially spaced apart, axially extending wall portions (66, 82) of the stator structure. A non-magnetic sleeve member (110) has a tubular cylindrical side wall disposed radially between these stator wall portions and the cylindrical tubular walled portion of the armature. The sleeve has an end wall disposed for abutment with the armature to define a limit of axial travel for the armature-pintle assembly and to provide a spring seat for a helical coiled spring that biases the armature-pintle assembly normally closed. More accurate assembly of component parts and shaping of certain parts provide better control and reduced hysteresis.
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