Exhaust gas recirculation valve

• US 5,687,698 A
• Filed: 08/29/1996
• Issued: 11/18/1997
• Est. Priority Date: 08/29/1996
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Mastro, Noreen Louise, Rohe, Jeffrey David
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US08/703,149
• Time in Patent Office: 446 Days
• Field of Search: 123/571, 251/129.15, 251/129.16, 251/129.17, 335/219, 335/220, 335/221, 335/236, 335/255, 335/278, 335/279, 335/281
• US Class Current: 123/568.26
• CPC Class Codes: F02M 26/48 EGR valve position sensors details of the sensor installation in the valve housing F02M26/72
• CPC Class Codes: F02M 26/53 using electric actuators, e.g. solenoids
• CPC Class Codes: F02M 26/67 Pintles; Spindles; Springs; Bearings; Sealings; Connections to actuators
• CPC Class Codes: F02M 26/72 Housings
• CPC Class Codes: H01F 7/1607 Armatures entering the winding

Abstract

An exhaust gas recirculation valve meters exhaust gas to the intake of an internal combustion engine. The valve includes an electromagnetic solenoid actuator having a magnetic circuit defined by a primary and a secondary pole piece. The pole pieces define an axial chamber in which is disposed an axially moveable armature and an associated valve member. The primary pole piece has a center pole member including a cylindrical inner wall which is open at a first end for receiving the armature. The armature and the cylindrical inner wall establish a fixed, radially extending primary air gap for flux passage while the outer wall extends in an outward taper from the first, open end of said center pole member and operates to increase the mass of the pole piece through which the magnetic circuit operates as the armature moves from the first, open end of the center pole member towards the second end. The secondary pole piece has a center pole member which includes a cylindrical inner wall, open at a first end for receiving the moveable armature and which is located in spaced opposing relationship to the first, open end of the primary pole to define a pole-to-pole gap therebetween. The armature and the cylindrical inner wall of the secondary pole define fixed, radially extending primary air gap for flux passage thereacross, and the outer wall extends in an outward taper from the first, open end. The outwardly tapering walls of primary and secondary poles operate to minimize the pole-to-pole gap through a minimization in opposing surface area therebetween allowing the length of the secondary pole and the surface area between secondary pole member and the armature to be maximized. The result is a minimization of the reluctance across said radial air gap and a maximization of the flux passage through the armature.

Claims

1. A valve assembly for metering exhaust gas to the intake of an internal combustion engine comprising an electromagnetic solenoid actuator having a magnetic circuit including primary and secondary poles defining an axial chamber and an armature, associated with a valve member, and moveable in said chamber, said primary pole defined by a center pole member including a cylindrical inner wall, open at a first end for receiving said moveable armature, said armature and said cylindrical inner wall defining a fixed, radially extending primary air gap for flux passage thereacross, and an outer wall extending in an outward taper from said first, open end of said center pole member, said outwardly tapering wall operable to increase the mass of the pole piece through which said magnetic circuit operates as said armature moves from said first, open end of said pole towards a second end, said secondary pole defined by a center pole member including a cylindrical inner wall, open at a first end, for receiving said moveable armature, said first end located in spaced opposing relationship to said first, open end of said primary pole to define a pole-to-pole gap therebetween, said armature and said cylindrical inner wall defining a fixed, radially extending primary air gap for flux passage thereacross, and an outer wall extending in an outward taper from said first, open end of said center pole., said outwardly tapering walls of said primary and said secondary poles operable to minimize the pole-to-pole gap through a minimization in opposing surface area between said first end of said primary pole and said first end of said secondary pole to thereby maximize the length of said secondary pole and the surface area between said secondary pole member and said armature to thereby minimize the reluctance across said radial air gap and maximize the passage of flux through said armature.