Relative position sensing for an exhaust gas recirculation valve

• US 20050092308A1
• Filed: 11/01/2004
• Published: 05/05/2005
• Est. Priority Date: 10/31/2003
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Tsokonas, Stavros
• Granted Patent: US 7,124,750 B2
• Time in Patent Office: Days
• US Class Current: 123/568.23
• 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 26/54 Rotary actuators, e.g. step motors
• CPC Class Codes: F02M 26/67 Pintles; Spindles; Springs; Bearings; Sealings; Connections to actuators

Abstract

An exhaust gas recirculating valve includes a body, a closure member, a magnet, and a magneto-resistive sensor. The body defines a passage through which exhaust gas flows. The body includes a seat and the passage includes an aperture defined by the seat. The closure member is displaced between first and second configurations with respect to the seat. The first configuration sets at zero percent a percentage of exhaust gas that flows from an exhaust manifold of an internal combustion engine to an intake manifold of the internal combustion engine, and the second configuration sets at 100 percent the percentage of exhaust gas that flows from the exhaust manifold of the internal combustion engine to the intake manifold of the internal combustion engine. The magnet moves congruently with the closure member, and the magneto-resistive sensor detects the movement of the magnet so as to determine the percentage of exhaust gas flow.

Claims

1. An exhaust gas recirculating valve comprising:

a body defining a passage through which exhaust gas flows, the body includes a seat, and the passage includes an aperture defined by the seat;

a closure member being displaced between first and second configurations with respect to the seat, the first configuration setting at zero percent a percentage of exhaust gas flowing from an exhaust manifold of an internal combustion engine to an intake manifold of the internal combustion engine, and the second configuration setting at 100 percent the percentage of exhaust gas flowing from the exhaust manifold of the internal combustion engine to the intake manifold of the internal combustion engine;

a magnet moving congruently with the closure member; and

a magneto-resistive sensor detecting movement of the magnet so as to determine the percentage.

2. The system according to claim 1, wherein the valve comprises:

an electromagnetic actuator displacing the closure member along an axis between the first and second configurations of the closure member; and

a first resilient element extending between the body and the closure member, the first resilient element biasing the closure member toward the first configuration of the closure member.

3. The system according to claim 2, wherein the electromagnetic actuator comprises at least one of an electric solenoid and an electric motor.

4. The system according to claim 1, wherein the closure member comprises a head and a stem extending from the head, the head contiguously engages the seat so as to occlude the aperture in the first configuration, and the head is spaced from the seat in the second configuration.

5. A valve comprising:

a seat defining an aperture;

a closure member being displaced between a first configuration occluding the aperture and a second configuration being spaced from the seat;

a magnet moving congruently with the closure member; and

a sensor detecting movement of the magnet so as to quantify positioning of the closure member with respect to the seat.

6. The valve according to claim 5, wherein the second configuration of the closure member comprises internal combustion engine exhaust gas flowing through the aperture.

7. The valve according to claim 5, wherein the magnet is fixed to the closure member.

8. The valve according to claim 5, further comprising:

a resilient element biasing the magnet into contiguous engagement with the closure member.

9. The valve according to claim 8, wherein the closure member comprises a head and a stem, the head contiguously engages the seat in the first configuration of the closure member, and the resilient element biases the magnet into contiguous engagement with the stem.

10. The valve according to claim 5, further comprising:

a body defining a fluid passage extending between an inlet and an outlet, the fluid passage including the aperture.

11. The valve according to claim 10, further comprising:

a motive force device displacing the closure member between the first and second configurations.

12. The valve according to claim 11, wherein the motive force device comprises a stator and an armature, the stator being fixed with respect to the body, and the armature being coupled to the closure member.

13. The valve according to claim 12, wherein the motive force device comprises an electric solenoid.

14. The valve according to claim 13, further comprising:

a follower fixed to the magnet;

a resilient element biasing the follower into contiguous engagement with the armature; and

a bearing supporting the follower for displacement with respect to the body.

15. The valve according to claim 12, wherein the motive force device comprises an electric motor.

16. The valve according to claim 15, wherein a coupling between the armature and the closure member comprises a converter of rotary motion to linear motion including a threaded rod and a nut cooperatively engaging the threaded rod, the nut being rotated by the armature, and the threaded rod being translated with respect to the body.

17. The valve according to claim 16, further comprising:

a follower fixed to the magnet;

a resilient element biasing the follower into contiguous engagement with the threaded rod; and

a bearing supporting the follower for displacement with respect to the body.

18. The valve according to claim 10, further comprising:

a resilient element extending between the closure member and the body, the resilient element biasing the closure member toward the first configuration of the closure member.

19. The valve according to claim 10, wherein the sensor is fixed with respect to the body.

20. The valve according to claim 5, wherein the sensor comprises a magneto-resistive sensor.

21. The valve according to claim 20, wherein the magneto-resistive sensor is electrically coupled to a Wheatstone bridge.

22. A system to recirculate exhaust gas from an exhaust manifold of an internal combustion engine to an intake manifold of the internal combustion engine, the system comprising:

an inlet conduit being coupled to the exhaust manifold and receiving a first supply of the exhaust gas;

an outlet conduit being coupled to the intake manifold and delivering a second supply of the exhaust gas, the second supply being a percentage of the first supply; and

a valve coupled between the inlet and outlet conduits, the valve setting the percentage of the first supply that is the second supply, the valve including;

a seat defining an aperture;

a closure member being displaced between first and second configurations with respect to a seat, the first configuration setting the percentage at zero percent, and the second configuration setting the percentage at 100 percent;

a magnet moving congruently with the closure member; and

a magneto-resistive sensor detecting movement of the magnet so as to determine the percentage.

23. The system according to claim 22, wherein the valve comprises:

a body defining a fluid passage providing exhaust gas communication between the inlet and outlet conduits, the body includes a seat and the fluid passage includes an aperture in the seat, the aperture is occluded by the closure member in the first configuration, the closure member is spaced from the seat in the second configuration, and the magneto-resistive sensor is fixed with respect to the body;

a first resilient element extending between the body and the closure member, the first resilient element biasing the closure member along an axis toward the first configuration of the closure member; and

an electromagnetic actuator displacing the closure member between the first and second configurations of the closure member.

24. The system according to claim 23, wherein the closure member comprises a head and a stem, the head contiguously engages the seat in the first configuration, and the stem projects from the head and extends along the axis.

25. The system according to claim 24, wherein the electromagnetic actuator comprises:

an electric solenoid displacing the closure member between the first and second configurations of the closure member, the electric solenoid includes a stator being fixed to with respect to the body and an armature fixed with respect to the stem of the closure member; and

a first bearing supporting translation along the axis of the armature with respect to the body.

26. The system according to claim 25, wherein the valve comprises:

a follower translating along the axis, the magnet being fixed to the follower;

a second bearing supporting translation along the axis of the follower with respect to the body; and

a second resilient element extending between the body and the follower, the second resilient element biasing the follower into contiguous engagement with the armature.

27. The system according to claim 23, wherein the electromagnetic actuator comprises:

an electric motor displacing the closure member between the first and second configurations of the closure member, the electric motor including a stator being fixed with respect to the body, and the armature rotating about the axis;

a converter of rotary motion to linear motion including a threaded rod and a nut cooperatively engaging the threaded rod, the nut rotating with the armature, and the threaded rod translating along the axis so as to displace the closure member from the first configuration toward the second configuration; and

a first bearing supporting translation along the axis of the threaded rod with respect to the body.

28. The system according to claim 27, wherein the valve comprises:

a follower translating along the axis, the magnet being fixed to the follower;

a second bearing supporting translation along the axis of the follower with respect to the body; and

a second resilient element extending between the body and the follower, the second resilient element biasing the follower into contiguous engagement with the threaded rod.

29. The system according to claim 22, wherein the magneto-resistive sensor is electrically coupled to a Wheatstone bridge.

30. A relative positioning sensor for a first element that is displaced along an axis with respect to a second element, the relative positioning sensor comprising:

a magnet moving congruently with the first element; and

a magneto-resistive detector of the magnet moving so as to quantify relative positioning of the first and second elements.

31. The relative position sensor according to claim 30, further comprising:

a Wheatstone bridge electrically coupled to the magneto-resistive detector.

32. A method of quantifying relative positioning between a movable element that is displaced along an axis with respect to a fixed element, the method comprising:

coupling a magnet to a first one of the movable and fixed elements, the magnet developing a magnetic field;

disposing a magnetic field sensor on a second one of the movable and fixed elements;

detecting with the magnetic field sensor changes in orientation of the magnetic field as the movable element is displaced along the axis with respect to the fixed element.

33. The method according to claim 32, wherein the disposing comprises spacing the magnetic field sensor a first lateral distance from the axis.

34. The method according to claim 33, wherein the spacing comprises preventing contiguous contact between the magnet and the magnetic field sensor.

35. The method according to claim 34, wherein the spacing comprises the magnetic field having a strength of at least 25 henries at the first lateral distance from the axis.

36. The method according to claim 35, wherein the detecting is insensitive to changes in the strength of the magnetic field.

37. The method according to claim 32, further comprising:

outputting a signal quantifying relative positioning between the movable and fixed elements, the signal being determined based on the detecting.