Rotary diesel electric EGR valve

• US 5,531,205 A
• Filed: 03/31/1995
• Issued: 07/02/1996
• Est. Priority Date: 03/31/1995
• Status: Expired due to Term

• Current Assignee: Siemens Electric Limited
• Original Assignee: Siemens Electric Limited
• Inventors: Cook, John E., Hussey, Scott E. W.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US08/414,454
• Time in Patent Office: 459 Days
• Field of Search: 123/568, 123/569, 123/571, 251/305, 251/306, 251/307
• US Class Current: 123/568.24
• CPC Class Codes: F02D 9/101 Special flap shapes, ribs, bores or the like
• CPC Class Codes: F02D 9/1045 for sealing of the flow in closed flap position, e.g. the housing forming a valve seat
• CPC Class Codes: F02D 9/1065 Mechanical control linkage between an actuator and the flap, e.g. including levers, gears, springs, clutches, limit stops of the like
• CPC Class Codes: F02M 26/54 Rotary actuators, e.g. step motors
• CPC Class Codes: F02M 26/70 Flap valves; Rotary valves; Sliding valves; Resilient valves
• CPC Class Codes: F05C 2201/021 Aluminium

Abstract

An EGR valve is well-suited for use in a diesel engine by employing a butterfly-type valve operated by a torque motor. Sealing of the butterfly blade to the wall of the passage through the valve body utilizes a sealing ring that is mounted in a groove of the passage wall. The blade and the sealing ring are self-aligned at assembly, and the groove is cooperatively defined by two body segments that are fitted axially together to capture the sealing ring. Two additional rings are used between the sealing ring and the sides of the groove. In certain embodiments, the axis of the passage in the vicinity of the groove is straight; in others, it has a 45 degree offset so that portions of the axis to opposite sides of the groove are non-collinear.

Claims

1. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising a body, an inlet at which engine exhaust gas to be recirculated enters said body, a walled passage that has its own axis and that extends through said body for conveying engine exhaust gas that has entered said inlet, an outlet at which engine exhaust gas that has passed through said walled passage exits said body, a valve blade that is disposed within said walled passage and is selectively positionable within said walled passage for selectively restricting flow through said walled passage, actuating means disposed exterior of said walled passage, an actuating shaft operatively coupling said actuating means with said valve blade for selectively positioning said valve blade between a closed position wherein said valve blade is sealed relative to said walled passage and a number of increasingly open positions, and a sealing ring mounted on, and extending peripherally around, said walled passage, said sealing ring having its own axis and comprising opposite end surfaces facing in opposite axial directions relative to said sealing ring'"'"'s axis and a radially inward surface extending between said opposite end surfaces, said valve body comprising respective body segments disposed end-to-end axially along said walled passage'"'"'s axis and cooperatively defining a groove that is radially inwardly open relative to said walled passage'"'"'s axis and within which said sealing ring is disposed, and means providing for said sealing ring to position itself within said groove during the process of assembling the EGR valve such that said radially inward surface of said sealing ring concentrically seals to an outer perimeter of said valve blade when said valve blade is in closed position, said groove comprising confronting wall surfaces that are axially spaced apart along said walled passage'"'"'s axis, and said means providing for said sealing ring to position itself within said groove during the process of assembling the EGR valve including separate individual elements in association with said groove, each separate individual element being disposed between a respective one of said confronting wall surfaces of said groove and a respective end surface of said sealing ring, one of said separate individual elements comprising a resilient portion for resiliently urging said sealing ring against the other of said separate individual elements, and including a sealing means disposed radially outwardly of said groove relative to said walled passage'"'"'s axis for sealing between said body segments so that engine exhaust gas does not leak out of said walled passage between said body segments.

2. An EGR valve as set forth in claim 1 in which said body segments are aluminum or an aluminum alloy, and said separate individual elements are stainless steel.

3. An EGR valve as set forth in claim 1 in which a portion of said walled passage'"'"'s axis that extends axially coextensive with and immediately contiguous said groove both toward said inlet and toward said outlet is straight and said sealing ring'"'"'s axis is disposed substantially coaxial with said portion of said walled passage'"'"'s axis.

4. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising a body, an inlet at which engine exhaust gas to be recirculated enters said body, a walled passage that has its own axis and that extends through said body for conveying engine exhaust gas that has entered said inlet, an outlet at which engine exhaust gas that has passed through said walled passage exits said body, a valve blade that is disposed within said walled passage and is selectively positionable within said walled passage for selectively restricting flow through said walled passage, actuating means disposed exterior of said walled passage, an actuating shaft operatively coupling said actuating means with said valve blade for selectively positioning said valve blade between a closed position wherein said valve blade is sealed relative to said walled passage and a number of increasingly open positions, and a sealing ring mounted on, and extending peripherally around, said walled passage, said sealing ring having its own axis and comprising opposite end surfaces facing in opposite axial directions relative to said sealing ring'"'"'s axis and a radially inward surface extending between said opposite end surfaces, said valve body comprising respective body segments disposed end-to-end axially along said walled passage'"'"'s axis and cooperatively defining a groove that is radially inwardly open relative to said walled passage'"'"'s axis and within which said sealing ring is disposed, and means providing for said sealing ring to position itself within said groove during the process of assembling the EGR valve such that said radially inward surface of said sealing ring concentrically seals to an outer perimeter of said valve blade when said valve blade is in closed position, and in which a portion of said walled passage'"'"'s axis that extends axially coextensive with and immediately contiguous said groove both toward said inlet and toward said outlet comprises an offset that causes respective segments of said walled passage'"'"'s axis that are respectively toward said inlet and toward said outlet relative to said groove to be non-colinear, and said sealing ring is disposed substantially at 45 degrees to said respective segments of said walled passage'"'"'s axis.

5. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising a body, an inlet at which engine exhaust gas to be recirculated enters said body, a walled passage that has its own axis and that extends through said body for conveying engine exhaust gas that has entered said inlet, an outlet at which engine exhaust gas that has passed through said walled passage exits said body, a valve blade that is disposed within said Walled passage and is selectively positionable within said walled passage for selectively restricting flow through said walled passage, actuating means, an actuating shaft operatively coupling said actuating means with said valve blade for selectively positioning said valve blade by means of said actuating means between a maximally open position wherein said valve blade minimally restricts said walled passage and a closed position wherein said valve blade is sealed relative to said walled passage by a sealing ring mounted on, and extending peripherally around, said walled passage, said sealing ring having an inside perimeter against which an outside perimeter of said valve blade seals when in closed position, and wherein said actuating means causes said actuating shaft to execute substantially 45 degrees of rotary motion for operating said valve blade between maximally open position, where said outside perimeter of said valve blade occupies a plane that is substantially parallel with a general direction of flow parallel to said axis at the location of said blade along said walled passage when said blade is in maximally open position, and closed position where said sealing ring'"'"'s inside perimeter seals against said outside perimeter of said valve blade.

6. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising a body, an inlet at which engine exhaust gas to be recirculated enters said body, a walled passage that has its own axis and that extends through said body for conveying engine exhaust gas that has entered said inlet, an outlet at which engine exhaust gas that has passed through said walled passage exits said body, a valve blade that is disposed within said walled passage and is selectively positionable within said walled passage for selectively restricting flow through said walled passage, actuating means, an actuating shaft operatively coupling said actuating means with said valve blade for selectively positioning said valve blade by means of said actuating means between a maximally open position wherein said valve blade minimally restricts said walled passage and a closed position wherein said valve blade is sealed relative to said walled passage, sealing means for sealing said valve blade relative to said walled passage when said valve blade is in closed position comprising a sealing ring mounted on, and extending peripherally around, said walled passage, said sealing ring having an inside perimeter against which an outside perimeter of said valve blade seals when in closed position, and wherein said actuating means causes said actuating shaft to execute substantially 45 degrees of rotary motion for operating said valve blade between maximally open position and closed position, and in which a portion of said walled passage'"'"'s axis that extends axially coextensive with and immediately contiguous said groove both toward said inlet and toward said outlet comprises an offset that causes respective segments of said walled passage'"'"'s axis that are respectively toward said inlet and toward said outlet relative to said groove to be non-colinear, and said sealing ring is disposed substantially at an acute angle to said respective segments of said walled passage'"'"'s axis.

7. An EGR valve as set forth in claim 6 in which said actuating means comprises a rotary torque motor disposed exterior of said walled passage, and said actuating shaft extends from said rotary torque motor into said walled passage.

8. An EGR valve as set forth in claim 7 in which said actuating shaft has an axis that substantially intersects and is disposed at about 70 degrees to one of said respective segments of said walled passage'"'"'s axis.

9. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising a body, an inlet at which engine exhaust gas to be recirculated enters said body, a walled passage that has its own axis and that extends through said body for conveying engine exhaust gas that has entered said inlet, an outlet at which engine exhaust gas that has passed through said walled passage exits said body, a valve blade that is disposed within said walled passage and is selectively positionable within said walled passage for selectively restricting flow through said walled passage, actuating means, an actuating shaft operatively coupling said actuating means with said valve blade for selectively positioning said valve blade by means of said actuating means between a maximally open position wherein said valve blade minimally restricts said walled passage and a closed position wherein said valve blade is sealed relative to said walled passage, sealing means for sealing said valve blade relative to said walled passage when said valve blade is in closed position comprising a sealing ring mounted on, and extending peripherally around, said walled passage, said sealing ring having an inside perimeter against which an outside perimeter of said valve blade seals when in closed position, and wherein said actuating means causes said actuating shaft to execute substantially 45 degrees of rotary motion for operating said valve blade between maximally open position and closed position, said valve body comprises respective axially extending body segments disposed axially end-to-end and cooperatively defining a radially inwardly open groove within which said sealing ring is disposed, said groove comprising opposed axially facing wall surfaces, and including means providing for said sealing ring to position itself within said groove during the process of assembling the EGR valve comprising respective individual elements associated with said groove, each respective individual element being disposed between a respective one of said axially facing wall surfaces and a respective axially facing end surface of said sealing ring, and including a further sealing means disposed radially outwardly of said groove for sealing between said body segments so that engine exhaust gas does not leak out of said walled passage between said body segments.

10. An EGR valve as set forth in claim 9 in which said body segments are aluminum or an aluminum alloy and said elements are stainless steel.

11. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising a body, an inlet at which engine exhaust gas to be recirculated enters said body, a walled passage that has its own axis and that extends through said body for conveying engine exhaust gas that has entered said inlet, an outlet at which engine exhaust gas that has passed through said walled passage exits said body, a valve blade that is disposed within said walled passage and is selectively positionable within said walled passage for selectively restricting flow through said walled passage, said valve blade comprising a perimeter that is substantially co-planar, actuating means comprising a rotary torque motor and an actuating shaft that operatively couples said actuating means with said valve blade for selectively positioning said valve blade by means of said rotary torque motor between a minimally restrictive position wherein said valve blade minimally restricts said walled passage and a maximally restrictive position wherein said valve blade maximally restricts said walled passage, and wherein said actuating shaft is affixed to a region of said valve blade that is bounded by said valve blade'"'"'s perimeter and is disposed at an acute angle to the plane of said valve blade'"'"'s perimeter, and in which said actuating shaft executes substantially about 45 degrees of rotation about its own axis to operate said valve blade between the minimally restrictive position and the maximally restrictive position.

12. An EGR valve as set forth in claim 11 in which said acute angle is substantially about 20 degrees.

13. An EGR valve as set forth in claim 11 including sealing means for sealing said valve blade relative to said walled passage when said valve blade is in maximally restrictive position to close said walled passage to engine exhaust gas flow, said sealing means comprising a sealing ring mounted on, and extending peripherally around, said walled passage and being disposed for engagement by said perimeter of said valve blade.

14. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising:

a body;

a walled passage extending through said body, and defining an axis, for conveyance of exhaust gas therethrough, wherein a portion of said walled passage'"'"'s axis comprises an offset that causes respective segments of said walled passage'"'"'s axis that extend from respective opposite ends of said offset to be non-colinear;

a valve blade which is disposed within said walled passage, and which is selectively positionable therein for selectively restricting exhaust gas flow through said walled passage;

an actuating shaft coupled to said valve blade and oriented at an acute angle relative to the axis; and

a rotary torque motor operatively coupled to said actuating shaft, for positioning said valve blade between a closed position wherein said blade obturates that portion of said walled passage'"'"'s axis that comprises an offset and a maxially open position wherein an outer perimeter of said blade occupies a plane that is substantially parallel with said respective segments of said walled passage'"'"'s axis that extend from said respective opposite ends of said offset.

15. An EGR valve as set forth in claim 14 including sealing means for sealing said valve blade relative to that portion of said walled passage'"'"'s axis that comprises an offset when said valve blade is in closed position, said sealing means comprising a sealing ring mounted on, and extending peripherally around, that portion of said walled passage'"'"'s axis that comprises an offset and being disposed for engagement by said outer perimeter of said valve blade.

16. An exhaust gas recirculation (EGR) valve for an internal combustion engine comprising a body, an inlet at which engine exhaust gas to be recirculated enters said body, a walled passage that has its own axis and that extends through said body for conveying engine exhaust gas that has entered said inlet, an outlet at which engine exhaust gas that has passed through said walled passage exits said body, a valve blade that is disposed within said walled passage and is selectively positionable within said walled passage for selectively restricting flow through said walled passage, actuating means disposed exterior of said walled passage, an actuating shaft operatively coupling said actuating means with said valve blade for selectively positioning said valve blade between a closed position wherein said valve blade is sealed relative to said walled passage and a number of increasingly open positions, and a sealing ring mounted on, and extending peripherally around, said walled passage, said sealing ring having its own axis and comprising opposite end surfaces facing in opposite axial directions relative to said sealing ring'"'"'s axis and a radially inward surface extending between said opposite end surfaces, said valve body comprising respective body segments disposed end-to-end axially along said walled passage'"'"'s axis and cooperatively defining a groove that is radially inwardly open relative to said walled passage'"'"'s axis and within which said sealing ring is disposed, and means providing for said sealing ring to position itself within said groove during the process of assembling the EGR valve such that said radially inward surface of said sealing ring concentrically seals to an outer perimeter of said valve blade when said valve blade is in closed position, said groove comprising confronting wall surfaces that are axially spaced apart along said walled passage'"'"'s axis, and said means providing for said sealing ring to position itself within said groove during the process of assembling the EGR valve including a separate individual element in association with said groove and disposed between one of said confronting wall surfaces of said groove and one end surface of said sealing ring, said separate individual element comprising a resilient portion for resiliently urging said sealing ring away from said respective one of said confronting wall surfaces of said groove, and including a sealing means disposed radially outwardly of said groove relative to said walled passage'"'"'s axis for sealing between said body segments so that engine exhaust gas does not leak out of said walled passage between said body segments.

17. An exhaust gas recirculation (EGR) valve as set forth in claim 16 including a further separate individual element in association with said groove and disposed between another of said confronting wall surfaces of said groove and another of said opposite end surfaces of said sealing ring, said resilient portion of said firstmentioned separate element resiliently urging said sealing ring against said further separate individual element.