Claims
- 1. An exhaust gas recirculation valve (10) for an engine including a valve housing (14), a motor housing (12), and a sensor housing (16), comprising:an armature (30) disposed in the motor housing (12), said armature (30) being moveable so as to cause a valve (10) to move into and out of contact with a valve seat (120); an armature (30) bearing disposed in said motor housing (12) and positioned to contact the outer periphery of said armature (30); a flux return (46) having an end (54) in communication with an upper portion (68) of said armature bearing (66); a pole piece (56) having an end (58) in communication with a lower portion (70) of said armature bearing (66); wherein one of said end (54) of said flux return (46) or said end (58) of said pole piece (56) are located so as to reduce an air gap (200) therebetween to cause magnetic shorting therebetween.
- 2. The valve of claim 1, wherein electromechanical damping is induced into the system.
- 3. The valve of claim 1, wherein both said end (54) of said flux return (46) and said end (58) of said pole piece (56) are lengthened in order to reduce said air gap.
- 4. A method for reducing dithering in a solenoid exhaust gas recirculation valve (10), having a valve housing (14), a motor housing (12), and a sensor housing (16), comprising:providing a duty cycle signal to the valve (10) from an engine computer to open the valve (10) an amount proportional to said duty cycle; sensing the amount of exhaust gas flowing through said open valve to an intake manifold; providing a feedback signal to said engine computer in order to accurately control the position of the valve (10); and inducing electromechanical damping into the valve to reduce oscillation of the valve.
- 5. The method of claim 4, further comprising:reducing an air gap (200) between a flux return (46) and a pole piece (56).
- 6. The method of claim 4, further comprising:reducing an air gap (200) between a flux return (46) and a pole piece (56) by lengthening one of said flux return (46) or said pole piece (56) to cause a short therebetween.
- 7. The method of claim 6, further comprising increasing the length of each of said flux return and said pole piece (156) in order to reduce said air gap (200).
- 8. An exhaust gas recirculation valve for an engine, comprising:a valve housing (14), including a valve inlet adapted to receive exhaust gas, a valve seat surrounding a valve opening, through which said received exhaust gas passes, and a valve outlet adapted to communicate said received exhaust gas to an engine intake; a motor housing (12) having disposed therein a solenoid coil, an armature (30), and a valve stem in communication with said armature (30) and linearly moveable so as to open and close the communication between said valve inlet and said engine intake; a sensor housing (16) having an electromagnetic mechanism therein to monitor the position of said valve stem and thus said armature; a guide bearing (66) disposed within said motor housing and in communication with an outside surface of said armature to accurately position said armature concentrically within said motor housing; a flux return (46) in communication with said guide bearing (66) at an upper surface; a pole piece (56) in communication with said guide bearing (66) at a lower surface; and an air gap (200) formed between said flux return (46) and said pole piece (56) which is sized to cause electromechanical damping therebetween.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. patent application Ser. No. 09/610,805, filed on Jul. 6, 2000, still pending, which is a continuation-in-part of U.S. application Ser. No. 09/266,650 filed on Mar. 11, 1999, now U.S. Oat. No. 6,182,646.
US Referenced Citations (22)
Foreign Referenced Citations (3)
Number |
Date |
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0 428 274 |
May 1991 |
EP |
0 900 931 |
Oct 1999 |
EP |
0 900 931 |
Oct 1999 |
EP |
Continuation in Parts (2)
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Number |
Date |
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Parent |
09/610805 |
Jul 2000 |
US |
Child |
09/784617 |
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US |
Parent |
09/266650 |
Mar 1999 |
US |
Child |
09/610805 |
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US |