Butterfly Valve for Egr Drosselklappenventil Für Abgasrückführung Vanne Papillon Pour La Remise En Circulation De Gaz D’Echappement

Europäisches Patentamt *EP000817909B1* (19) European Patent Ofﬁce

Ofﬁce européen des brevets (11) EP 0 817 909 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.7: F02M 25/07, F16K 1/22, of the grant of the patent: F16K 1/226 17.01.2001 Bulletin 2001/03 // H02K26/00, H01F7/14 (21) Application number: 96903852.0 (86) International application number: PCT/CA96/00133 (22) Date of ﬁling: 06.03.1996 (87) International publication number: WO 96/30639 (03.10.1996 Gazette 1996/44)

(54) BUTTERFLY VALVE FOR EGR DROSSELKLAPPENVENTIL FÜR ABGASRÜCKFÜHRUNG VANNE PAPILLON POUR LA REMISE EN CIRCULATION DE GAZ D’ECHAPPEMENT

(84) Designated Contracting States: • COOK, John, E. DE FR GB IT Chatham, Ontario N7L 2S8 (CA)

(30) Priority: 31.03.1995 US 414454 (74) Representative: Allen, Derek Siemens Group Services Limited, (43) Date of publication of application: Intellectual Property Department, 14.01.1998 Bulletin 1998/03 Siemens House, Oldbury (73) Proprietor: SIEMENS CANADA LIMITED Bracknell, Berkshire RG12 8FZ (GB) Mississauga, Ontario L5N 7A6 (CA) (56) References cited: (72) Inventors: EP-A- 0 604 835 WO-A-83/04430 • HUSSEY, Scott, E., W. WO-A-94/00858 FR-A- 1 572 497 Chatham, Ontario N7L 4V2 (CA) FR-A- 2 003 366 FR-A- 2 559 232 US-A- 4 198 940 US-A- 4 290 615

Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 0 817 909 B1

Printed by Jouve, 75001 PARIS (FR) 1 EP 0 817 909 B1 2

Description strict the flow. [0006] Another form of valve is disclosed in US-A- Field of the Invention 4198940. This patent discloses an exhaust gas recirculation system utilising an EGR valve. [0001] This invention relates generally to exhaust gas 5 [0007] Furthermore, a known butterfly valve is dis- recirculation (EGR) for internal combustion engines, closed in US-A-4290615 which comprises a valve blade and is particularly directed to an EGR valve that is es- disposed in a walled passage, which valve blade is op- pecially, although not exclusively, useful for controlling eratively coupled via an activating shaft to a rotary the recirculation of engine exhaust gas in a diesel en- torque motor for selectively controlling the position of gine. 10 the valve. The walled passage further includes a sealing ring disposed in a groove within the walled passage Background and Summary of the Invention which serves to effect a seal with the valve blade. [0008] FR-A-2003366 discloses a vacuum actuated [0002] Controlled engine exhaust gas recirculation is butterfly fluid flow valve comprising a bore and a valve a commonly used technique for reducing oxides of ni- 15 plate mounted in the bore. The valve plate extends at trogen in products of combustion that are exhausted an angle of 60° to the axis of the bore when it is in the from an internal combustion engine to atmosphere. A closed position and therefore only rotates 30° to the fully typical EGR system comprises an EGR valve that is open position. controlled in accordance with engine operating condi- [0009] An EGR valve must also be capable of with- tions to regulate the amount of engine exhaust gas that 20 standing the harsh operating environment where it is ex- is recirculated to the induction fuel-air flow entering the posed to wide temperature extremes and corrosive el- engine for combustion so as to limit the combustion tem- ements. Since governmental laws and regulations are perature and hence reduce the formation of oxides of typically applicable to an automotive vehicle's engine nitrogen. EGR system, the EGR valve must also be capable of [0003] Pintle-type EGR valves are commonly used, 25 performing satisfactorily over the duration for which but the presence of the pintle within the valve passage such laws and regulations are applicable to the vehicle's restricts the area of the passage that is available to con- engine exhaust emission control system. duct the flow, and hence for a given flow, the passage [0010] Sealing of the butterfly-valve relative to the diameter must be large enough to take the presence of wall of the passage through the valve body when the the pintle into account. A butterfly-type valve offers cer- 30 valve is fully closed may at times be quite important. tain advantages over a pintle-type, especially when ap- Moreover, the position of the sealing ring within a groove plied to a diesel engine. of the butterfly is also important in effecting a reliable [0004] Various operating conditions that an EGR seal to this and, a technical problem exists in ensuring valve may encounter in a typical diesel engine include that the sealing ring is correctly positioned. conditions where high flow rates must be conducted with 35 [0011] According to the present invention, there is minimal restriction and where large pressure differen- provided an exhaust gas recirculation (EGR) valve for tials may appear across the EGR valve. A butterfly-type an internal combustion engine as defined in claim 1. valve is capable of providing a low flow restriction oper- [0012] The present invention recognises certain dis- ating condition, and it is less sensitive to pressure dif- advantages of incorporating a sealing means on the but- ferentials acting across it because of its inherent force 40 terfly, and instead comprises a sealing ring mounted in balancing character. However, in order to take full ad- a groove in the wall of the passage. By placing the seal- vantage of a butterfly-type valve in a diesel engine ap- ing ring on the wall of the passage, instead of on the plication while satisfying all required operating condi- butterfly, the mass of the butterfly can be minimized, tions, a certain range of rotary motion is required. Ordi- thereby making for improved responsiveness of the but- narily, a butterfly-type valve must be rotated substantial- 45 terfly to commanded changes in position. Certain ma- ly 90 degrees between full open and full closed positions chining operations on the butterfly are also avoided. in order to take advantage of its desirable characteris- However, mounting the sealing ring in a groove in the tics. Such motion can be delivered to the valve by a lin- wall must be accomplished in such a way that the com- ear actuator and linkage system, but the linkage system plications of mounting it on the butterfly are not merely will typically add complexity and cost, and may even be 50 transferred to mounting it on the valve body; especially disadvantageous in certain applications. to be avoided are complex machining and assembly op- [0005] One known form of valve is disclosed in Euro- erations. pean patent EP-A-604835 which includes a body having [0013] In the inventive EGR valve, the groove is co- a walled passage in which is disposed a valve blade for operatively defined by two axially end-to-end joined seg- restricting the flow of a fluid medium through the pas- 55 ments of the valve body for advantageous assembly of sage when operated by an actuating means imparting the various component parts. The sealing ring and but- movement via an actuating shaft. The valve is provided terfly are self-aligned during the assembly process, and with sealing means which connects with the blade to re- the assembly process itself consists simply of fitting the

2 3 EP 0 817 909 B1 4 two end-to-end segments of the valve body together to haust gas that has entered inlet 18, and an outlet 24 at capture the sealing ring, and two associated parts, and which engine exhaust gas that has passed through said concurrently ensure the alignment of the butterfly to the passage 20 exits body segment 12b. Figs. 1 and 2 show sealing ring. butterfly 14 in closed operating position so that engine [0014] The preferred forms of the inventive valve use 5 exhaust gas is blocked from being recirculated through aluminium or aluminium alloy for the valve body seg- EGR valve 10. The wall of passage 20 is circular about ments, and to minimize the possibility of galvanic action axis 22, and axis 22 is straight so that the respective between the steel sealing ring and the aluminium valve sections of passage 20 in the respective body sections body, respective stainless steel elements are placed to 12a, 12b are co-axial. Butterfly 14 has a circular perim- each side of the groove between the sealing ring and 10 eter 14p that bounds a central region 14c. A circular the valve body. One of these elements is resiliently sealing ring 26 is mounted in a groove 28 in the wall of sprung so that resilient axial force is applied to the seal- passage 20, and Figs. 1 and 2 show perimeter 14p in ing ring. concentric sealing relation to sealing ring 26. [0015] A rotary torque motor is also advantageously [0026] Actuating mechanism 16 comprises a shaft 30 employed in the inventive valve in a unique geometric 15 to which central region 14c of butterfly 14 is affixed. relationship, and the two segment construction of the While perimeter 14p is co-planar and circular for sealing valve body facilitates the incorporation of this feature in- with sealing ring 26 in the closed position shown, central to the inventive valve. With 45 degrees of rotation of its region 14c comprises a shape that defines a non-circu- shaft, the torque motor accomplishes positioning of the lar hole 32 into which a matching non-circular distal end butterfly from a fully closed position to a position of min- 20 30a of shaft 30 is inserted. Butterfly 14 is attached to imum restriction of the flow passage. shaft end 30a such that rotary positioning of shaft 30 [0016] Further features, advantages, and benefits of about its own axis 34 will operate butterfly 14 and such the invention will be seen in the ensuing description and that exhaust gas will not leak through the attachment. claims that are accompanied by drawings. The drawings Axis 34 substantially intersects axis 22, but is skewed disclose a presently preferred embodiment of the inven- 25 at substantially about a 70 degree angle relative to the tion according to the best mode contemplated at this portion of axis 22 extending through body segment 12a, time for carrying out the invention. and at substantially about a 20 degree angle relative to the plane of perimeter 14p when the butterfly is closed Brief Description of the Drawings as shown. Since ring 26 is substantially perpendicular 30 to axis 22, it, like the closed butterfly 14, lies at substan- [0017] Fig. 1 is a longitudinal cross section through a tially about a 20 degree angle to axis 34. first embodiment of EGR valve embodying principles of [0027] When shaft 30 executes rotary motion in the the invention. clockwise sense as viewed in the direction of arrow 36 [0018] Fig. 2 is an enlarged view in circle 2 of Fig. 1. in Fig. 1, butterfly 14 will open. Fig. 3 shows butterfly 14 [0019] Fig. 3 is a view of a portion of Fig. 1 showing 35 in a partially open position, and Fig. 4, in maximally open a different operative position. position. In maximally open position, the plane of perim- [0020] Fig. 4 is a view similar to Fig. 3 showing a fur- eter 14p is substantially parallel with axis 22, and the ther operative position. butterfly imposes substantially minimal flow restriction. [0021] Fig. 5 is a longitudinal cross section through a Compound motion of butterfly 14 from the Fig. 1 closed second embodiment, with certain detail removed for il- 40 position (i.e., maximal flow restriction where it obturates lustrative purposes only. passage 20), to the Fig. 3 position of minimal flow re- [0022] Fig. 6 is a view similar to Fig. 5, but showing a striction occurs in response to substantially 45 degrees different operative position. of rotation of shaft 30 about axis 34. [0023] Fig. 7 is longitudinal cross section through a [0028] An electromechanical actuator that is capable third embodiment, with certain detail removed for illus- 45 of producing such a range of motion with the requisite trative purposes only. torque, speed, and accuracy is a rotary torque motor. Actuating mechanism 16 comprises such an actuator Description of the Preferred Embodiment 38. The exterior of body segment 12a is provided with an integral mounting 40 that serves both to journal shaft [0024] Figs. 1 and 2 show a first embodiment of in- 50 30 and to mount torque motor 38. Mount 40 comprises ventive EGR valve 10 in closed position. Valve 10 com- a base 42 disposed immediately proximate the joining prises: a valve body 12 having body segments 12a, 12b of segments 12a and 12b and a generally frustoconical joined together; a butterfly 14; and an actuating mech- wall 44 that flares outwardly from base 42 coaxial with anism, 16 generally, for operating butterfly 14. axis 34 to terminate in a circular rim 46. A shouldered [0025] Body 12 comprises an inlet 18 at which engine 55 through-hole extends through base 42 and serves to re- exhaust gas to be recirculated enters body segment tain in place a bushing 48 via which shaft 30 is journaled 12a, a walled passage 20 that has its own axis 22 and for rotary motion about axis 34. From its attachment to that extends through body 12 for conveying engine ex- butterfly 14, shaft 30 extends through bushing 48 and

3 5 EP 0 817 909 B1 6 terminates inside wall 44. The bushing and the passage the respective axially facing end surface 26a of sealing of the shaft through it are fluid tight so that exhaust gas ring 26, while ring 68 is disposed between wall surface cannot pass through to the interior of wall 44. 28b and the respective axially facing end surface 26b of [0029] Torque motor 38 comprises a housing having the sealing ring. Since body segments 12a, 12b are pref- a rim 50 that fits to rim 46 of mount 40. A retaining ring 5 erably aluminum or an aluminum alloy, rings 67, 68 are 52 holds the torque motor securely on rim 46. The torque stainless steel to reduce the possibility of galvanic action motor comprises the usual coil 54 and associated stator between the steel sealing ring 26 and the aluminum structure 56 for positioning the usual armature 58 about valve body 12. the torque motor's axis, which is coaxial with axis 34, [0032] Ring 68 is shaped with an axially extending and will therefore be similarly referenced. Armature 58 10 flange 70 that locates the ring in a circular groove 72 in includes a shaft 60 that is axially retained relative to sta- body segment 12a that is axially open toward body seg- tor structure 56 and journaled for rotary positioning ment 12b and coaxial with axis 22. Groove 72 is also about axis 34. A torsion spring 62 is disposed proximate spaced radially outwardly of groove 28 relative to axis the outer end of shaft 60 to act between stator structure 22. Ring 68 extends radially inwardly from flange 70 to 56 and shaft 60 for resiliently biasing shaft 60 about axis 15 radially overlap end surface 26b of sealing ring 26 and 34 to a position corresponding to butterfly 14 being in comprises resiliency for resiliently urging the opposite the closed position of Fig 1. As electric current is in- sealing ring surface 26a against ring 67 and the latter in creasingly applied to coil 54 (via electric terminals that turn against groove surface 28a. do not appear in the Figs.), an increasing electromag- [0033] As the two body segments 12a, 12b are moved netic torque is exerted on armature 58 causing the ar- 20 together end-to-end for assembly, the sealing ring and mature, and hence shaft 60, to increasingly turn about butterfly are self-aligned. Further radially outwardly of axis 34. This increasing torque is resisted by the in- groove 72 is a seal 76 for making the joint fluid tight so creasing counter-torque of spring 62, with the result be- that exhaust gas will not leak out between the two as- ing that the armature finally stops at a position about sembled body segments 12a, 12b. axis 34 determined by the current applied to coil 54. 25 [0034] Figs. 5 and 6 disclose an embodiment in which Thus, the rotary position of shaft 60 is a function of the a portion of axis 22 that extends axially coextensive with electric current supplied to coil 54, and this current is and immediately contiguous groove 28 both toward inlet determined by various operating conditions as detected 18 and toward outlet 24 comprises an offset 22a that by the engine control system, typically including an en- causes respective segments 22b, 22c of axis 22 that are gine management computer processing data from rele- 30 respectively toward the inlet and toward the outlet rela- vant sensors in accordance with one or more appropri- tive to the groove to be non-collinear. Sealing ring 26 ate algorithms. For providing torque motor position feed- and groove 28 are disposed in an offset section whose back to the engine management computer, a position axis portion 22a is substantially at 45 degrees to axis sensor 64 is mounted at the far end of the torque motor portions 22b, 22c. Fig. 5 shows the closed position, and housing and operatively coupled with the far end of shaft 35 Fig. 6 the open position. It can be seen that the circular 60. butterfly blade 14 executes 45 degrees of rotation about [0030] Wall 44 comprises an opening 65 providing for an axis 14x that lies on a diameter of the blade. Torque a clip 66 to be installed to couple the rotary motion of motor 38 can have its shaft coaxial with the diameter shaft 60 to shaft 30 so that the torque motor exercises about which the blade rotates and directly coupled to complete control of the positioning of butterfly 14. The 40 the blade with the sealing ring 26, groove 28, and the connections of the clip to the respective shafts are quite joint between the two body segments 12a, 12b being precise so that at most, any lost motion is negligible and suitably modified to accommodate passage of the con- insignificant. nection from the torque motor to the blade without intro- [0031] Another feature of the invention concerns the ducing exhaust gas leakage. The sealing ring is mount- manner of mounting sealing ring 26 on the wall of pas- 45 ed in similar fashion to that described earlier for the first sage 20. The respective axially extending body seg- embodiment although details are not specifically shown ments 12a, 12b are disposed axially end-to-end and co- in Figs. 5 and 6. operatively define the radially inwardly open groove 28 [0035] Fig. 7 shows a third embodiment where axis within which said sealing ring 26 is disposed. Groove 28 22 remains straight, but groove 28 is disposed in a cir- comprises opposed axially facing wall surfaces 28a, 28b 50 cular ridge 80 that extends around the inside of passage in segments 12a, 12b respectively. The groove also has 20. Like the previous two embodiments, Fig. 7 utilizes a radially inwardly facing wall surface 28c that lies on a two body segments 12a, 12b joined end-to-end and a circular diameter slightly greater than that of the outside mounting of the sealing ring 26 within groove 28 that diameter of sealing ring 26. That, plus the presence of provides for self-alignment of the butterfly blade to the two circular rings 67, 68, provide for sealing ring 26 to 55 sealing ring during assembly. The torque motor is used position itself within groove 28 during the process of as- to impart the same 45 degrees rotation to the butterfly sembling the component parts of EGR valve 10 togeth- in a manner analogous to that just described in connec- er. Ring 67 is disposed between wall surface 28a and tion with Figs. 5 and 6.

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Claims face (26a, 26b) of said sealing ring (26), one (68) of said circular rings (67, 68) resiliently urging an axi- 1. An exhaust gas recirculation (EGR) valve (10) for ally facing end surface (26a) of said sealing ring (26) an internal combustion engine, the valve compris- against the other (67) of said circular rings (67, 68) ing:- 5 with said other circular ring (67) being urged against one (28a) of said axially facing wall surfaces (28a, a body (12, 12a, 12b); 28b). an inlet (18) through which engine exhaust gas to be recirculated enters said body (12, 12a, 2. An EGR valve (10) as claimed in claim 1, wherein 12b); 10 said angle between said axis (34) of said actuating an outlet (24) from which engine exhaust gas means (16, 30, 30a, 38) and said axis (22; 22a, 22c) exits said body (12, 12a, 12b); of said walled passage (20) is substantially 70°. a walled passage (20) extending through said body (12, 12a, 12b) which connects said inlet 3. An EGR valve (10) as claimed in claim 1 or 2, (18) with said outlet (24), said walled passage 15 wherein said axis (22) of said walled passage (20) (20) being formed around an axis (22; 22a, 22b, is straight, and said sealing ring (26) is disposed 22c); substantially perpendicular to said axis (22). a valve blade (14, 14c, 14p, 14x) disposed within said walled passage (20), said valve blade 4. An EGR valve (10) as claimed in claim 1 or 2, (14, 14c, 14p, 14x) having a central region (14c) 20 wherein said axis (22a, 22c) of said walled passage and a perimeter (14p); (20) extends axially co-extensive with and immedi- actuating means (16, 30, 30a, 38) for selecting ately contiguous said groove (28) toward at least a plurality of positions for said valve blade (14, one of said inlet (18) and said outlet (24), and said 14c, 14p, 14x) to control exhaust gas ﬂow axis (22a, 22c) comprises an offset which causes through said walled passage (20), said actuat- 25 said body segments (12a, 12b) to be non-collinear, ing means (16, 30, 30a, 38) comprising a shaft and said sealing ring (26) is disposed substantially (30, 30a) having an axis (34) and which is cou- at an acute angle to said axis (22a, 22c) of said pled to said valve blade (14, 14c, 14p, 14x), walled passage (20). said axis (34) of said actuating means (16, 30, 30a, 38) being at an angle to said axis (22; 22a, 30 5. An EGR valve (10) as claimed in any one of the pre- 22c) of said walled passage (20) and said ac- ceding claims, wherein said body segments (12a, tuating means (16, 30, 30a, 38) operating to ro- 12b) comprise aluminium or an aluminium alloy, and tate said shaft (30, 30a) about its own axis said generally circular elements (67, 68) comprise through an angle of substantially 45° in order stainless steel. to rotate said valve blade(14, 14c, 14p, 14x) 35 about an axis (14x) between its maximally open 6. An EGR valve (10) as claimed in claim 3, wherein position and its closed position; said groove (28) is disposed in a circular ridge (80) sealing means (26, 67, 68) mounted in a groove extending around said walled passage (20). (28; 80) formed in said walled passage (20) for sealing against said perimeter (14p) of said 40 7. An EGR valve (10) as claimed in any preceding valve blade (14, 14c, 14p, 14x) when said valve claim, further comprising sealing means (76) dis- blade is in closed position; posed radially outwardly of said groove (28) for providing sealing between said body segments (12a, characterised in that said body (12, 12a, 12b) 12b) so that engine exhaust does not leak out of comprises two segments (12a, 12b) disposed axi- 45 said walled passage (20) between said body seg- ally end-to-end along said axis (22; 22a, 22c) of said ments (12a, 12b). walled passage (20) and which co-operatively de- ﬁne a radially inwardly open groove (28; 80) within 8. An EGR valve (10) as claimed in any preceding which said sealing means (26, 67, 68) is disposed, claim, wherein said actuating means (16, 30, 30a, said groove (28; 80) comprising opposed axially 50 38) comprises a rotary torque motor (38) disposed facing wall surfaces (28a, 28b) formed in respective exterior of said walled passage (20), and said actu- ones of the segments (12a, 12b), and in that said ating shaft (30, 30a) extends from said rotary torque sealing means (26, 67, 68) includes a sealing ring motor (38) into said walled passage (20). (26) and two circular rings (67, 68) for positioning said sealing ring (26) within the groove (28; 80), 55 each ring (67, 68) being disposed between a re- Patentansprüche spective one of said axially facing wall surfaces (28a, 28b) and a respective axially facing end sur- 1. Abgasrückführventil (EGR-Ventil) (10) für eine

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Brennkraftmaschine, welches aufweist: Ringe (67, 68) eine axial gerichtete Endfläche (26a) des Dichtringes (26) gegen die andere axial gerich- ein Gehäuse (12, 12a, 12b); tete Endfläche (67) der kreisförmigen Ringe (67, einen Einlaß (18), durch den rückzuführendes 68) elastisch andrückt, wobei der andere kreisför- Abgas in das Gehäuse (12, 12a, 12b) eintritt; 5 mige Ring (67) gegen eine (28a) der axial gerichte- einen Auslaß (24), durch den Abgas das Ge- ten Wandflächen (28a, 28b) angedrückt wird. häuse (12, 12a, 12b) verläßt; einen durch das Gehäuse (12, 12a, 12b) ver- 2. EGR-Ventil (10) nach Anspruch 1, bei dem der Win- laufenden Strömungskanal (20), der den Ein- kel zwischen der Achse (34) der Betätigungsmittel laß (18) mit dem Auslaß (24) verbindet, wobei 10 (16, 30, 30a, 38) und der Achse (22; 22a, 22c) des der Strömungskanal (20) auf einer Achse (22; Strömungskanals (20) im wesentlichen 70° beträgt. 22a, 22b, 22c) liegt; eine Ventilklappe (14, 14c, 14p, 14x), die in 3. EGR-Ventil (10) nach Anspruch 1 oder 2, bei dem dem Strömungskanal (20) angeordnet ist, wo- die Achse (22) des Strömungskanals (20) gerade bei die Ventilklappe (14, 14c, 14p, 14x) einen 15 verläuft und der Dichtring (26) im wesentlichen zentralen Bereich (14c) und einen Umfang senkrecht zu dieser Achse (22) angeordnet ist. (14p) hat; Betätigungsmittel (16, 30, 30a, 38) zum Wäh- 4. EGR-Ventil (10) nach Anspruch 1 oder 2, bei dem len mehrerer Stellungen der Ventilklappe (14, die Achse (22a, 22c) des Strömungskanals (20) in 14c, 14p, 14x), um den Abgasstrom durch den 20 axialer Richtung gemeinsam mit und unmittelbar Strömungskanal (20) zu steuern, wobei die Be- anschließend an der Nut (28) in Richtung auf min- tätigungsmittel (16, 30, 30a, 38) eine Welle (30, destens den Einlaß (18) oder Auslaß (24) verläuft, 30a) aufweisen, die eine Achse (34) hat und mit und daß die Achse (22a, 22c) einen Versatz hat, der der Ventilklappe (14, 14c, 14p, 14x) gekoppelt bewirkt, daß die Gehäusesegmente (12a, 12b) ist, die Achse (34) der Betätigungsmittel (16, 25 nicht kolinear sind, und daß der Dichtring (26) im 30, 30a, 38) unter einem Winkel zu der Achse wesentlichen unter einem spitzen Winkel zu der (22; 22a, 22c) des Strömungskanals (20) ange- Achse (22a, 22c) des Strömungskanals (20) angeordnet ist und die Betätigungsmittel (16, 30, ordnet ist. 30a, 38) die Welle (30, 30a) um ihre eigene Achse über einen Winkel von im wesentlichen 30 5. EGR-Ventil (10) nach einem der vorhergehenden 45° dreht, um die Ventilklappe (14, 14c, 14p, Ansprüche, bei dem die Gehäusesegmente (12a, 14x) zwischen ihrer maximal offenen Stellung 12b) Aluminium oder eine Aluminiumlegierung ent- und ihrer geschlossenen Stellung zu drehen; halten und die allgemein kreisförmigen Elemente Dichtmittel (26, 67, 68), die in einer Nut (28; 80) (67, 68) rostfreien Stahl enthalten. des Strömungskanals (20) angeordnet sind, 35 um den Umfang (14p) der Ventilklappe (14, 6. EGR-Ventil (10) nach Anspruch 3, bei dem die Nut 14c, 14p, 14x) abzudichten, wenn sich die Ven- (28) in einer kreisförmigen Rippe (80) angeordnet tilklappe ihrer geschlossenen Stellung befin- ist, die um den Strömungskanal (20) herum verläuft. det; 40 7. EGR-Ventil (10) nach einem vorhergehenden An- dadurch gekennzeichnet, daß das Gehäuse spruch, das ferner Dichtmittel (76) aufweist, die ra- (12, 12a, 12b) zwei Segmente (12a, 12b) aufweist, dial außerhalb der Nut (28) angeordnet sind, um ei- die längs der Achse (22; 22a, 22c) des Strömungs- ne Abdichtung zwischen den Gehäusesegmenten kanals (20) in axialer Richtung Ende an Ende an- (12a, 12b) zu bilden, so daß kein Abgas aus dem geordnet sind und gemeinsam eine radial einwärts 45 Strömungskanal (20) zwischen den Gehäuseseg- offene Nut (28; 80) bilden, innerhalb der die Dicht- menten (12a, 12b) leckt. mittel (26, 67, 68) angeordnet sind, wobei die Nut (28; 80) gegenüberliegende, axial gerichtete Wand- 8. EGR-Ventil (10) nach einem vorhergehenden An- flächen (28a, 28b) aufweist, die in den Segmenten spruch, bei dem die Betätigungsmittel (16, 30, 30a, (12a, 12b) entsprechend gebildet sind, und daß die 50 38) einen Drehmomentmotor (38) aufweisen, der Dichtmittel (26, 67, 68) einen Dichtring (26) und außerhalb des Strömungskanals (20) angeordnet zwei kreisförmige Ringe (67, 68) zum Positionieren ist, und daß die Betätigungswelle (30, 30a) von dem des Dichtringes (26) in der Nut (28; 80) aufweisen, Drehmomentmotor (38) aus in den Strömungskanal wobei jeder Ring (67, 68) zwischen einer entspre- (20) verläuft. chenden Wandfläche der axial gerichteten Wand- 55 flächen (28a, 28b) und einer entsprechenden axial gerichteten Endfläche (26a, 26b) des Dichtringes (26) angeordnet ist, einer (68) der kreisförmigen

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Revendications de paroi opposées (28a, 28b) faisant face axialement formées respectivement dans les segments 1. Soupape (10) de recyclage des gaz d'échappement (12a, 12b), et en ce que lesdits moyens d'étanchéité (EGR) pour un moteur à combustion interne, la sou- (26, 67, 68) comprennent une bague d'étanchéité pape comprenant : 5 (26) et deux bagues circulaires (67, 68) destinées à positionner ladite bague d'étanchéité (26) dans la un corps (12, 12a, 12b) ; gorge (28 ; 80), chaque bague (67, 68) étant dispo- une entrée (18) à travers laquelle les gaz sée entre une respective desdites surfaces de paroi d'échappement du moteur qu'il s'agit de recy- (28a, 28b) qui font face axialement et une surface cler entrent dans ledit corps (12, 12a, 12b) ; 10 d'extrémité respective (26a, 26b) faisant face axia- une sortie (24) par où les gaz d'échappement lement de ladite bague d'étanchéité (26), ladite une du moteur sortent dudit corps (12, 12a, 12b) ; (68) desdites bagues circulaires (67, 68) sollicitant un passage (20) délimité par une paroi qui élastiquement une surface d'extrémité (26a) faisant s'étend à travers ledit corps (12, 12a, 12b) qui face axialement de ladite bague d'étanchéité (26) relie ladite entrée (18) à ladite sortie (24), ledit 15 contre l'autre (67) desdites bagues circulaires (67, passage (20) délimité par une paroi étant formé 68), ladite autre bague circulaire (67) étant sollicitée autour d'un axe (22 ; 22a, 22b, 22c) ; contre l'une (28a) desdites surfaces de paroi (28a, un volet de soupape (14, 14c, 14p, 14x) dispo- 28b) faisant face axialement. sé dans ledit passage (20) délimité par une paroi, ledit volet de soupape (14, 14c, 14p, 14x) 20 2. Soupape de EGR (10) selon la revendication 1, ayant une région centrale (14c) et un périmètre dans laquelle ledit angle entre ledit axe (34), desdits (14p) ; moyens d'actionnement (16, 30, 30a, 38) et ledit des moyens d'actionnement (16, 30, 30a, 38) axe (22 ; 22a, 22c) dudit passage (20) délimité par destinés à sélectionner une pluralité de posi- une paroi est sensiblement de 70 °. tions pour ledit volet de soupape (14, 14c, 14p, 25 14x) afin de régler l'écoulement de gaz 3. Soupape de EGR (10) selon la revendication 1 ou d'échappement à travers ledit passage (20) dé- 2, dans laquelle ledit axe (22) dudit passage (20) limité par une paroi, lesdits moyens d'actionne- délimité par une paroi est droit, et ladite bague ment (16, 30, 30a, 38) comprenant un arbre d'étanchéité (26) est disposée sensiblement per- (30, 30a) présentant un axe (34) et qui est ac- 30 pendiculairement audit axe (22). couplé audit volet de soupape (14, 14c, 14p, 14x), ledit axe (34) desdits moyens d'actionne- 4. Soupape de EGR (10) selon la revendication 1 ou ment (16, 30, 30a, 38) étant incliné d'un angle 2, dans laquelle ledit axe (22a, 22c) dudit passage par rapport audit axe (22 ; 22a, 22c) dudit pas- (20) délimité par une paroi s'étend axialement en sage (20) délimité par une paroi et lesdits 35 coïncidence avec, et immédiatement contiguë à, la- moyens d'actionnement (16, 30, 30a, 38) en- dite gorge (28) vers au moins une de ladite entrée trant en action pour faire tourner ledit arbre (30, (18) et de ladite sortie (24) et ledit axe (22a, 22c) 30a) autour de son propre axe d'un angle de comprend un déport qui a pour effet que lesdits seg- sensiblement 45 ° afin de faire tourner ledit vo- ments (12a, 12b) du corps ne sont pas colinéaires, let de soupape (14, 14c, 14p, 14x) entre sa po- 40 et ladite bague d'étanchéité (26) est disposée sen- sition ouverte au maximum et sa position siblement en formant un angle aigu avec ledit axe fermée ; (22a, 22c) dudit passage (20) délimité par une pa- des moyens d'étanchéité (26, 67, 68) montés roi. dans une gorge (28 ; 80) formée dans ledit passage (20) délimité par une paroi pour s'appuyer 45 5. Soupape de EGR (10) selon une quelconque des à joint étanche contre ledit périmètre (14p) du- revendications précédentes, dans laquelle lesdits dit volet de soupape (14, 14c, 14p, 14x) lorsque segments (12a, 12b) du corps comprennent de ledit volet de soupape est dans une position l'aluminium ou un alliage d'aluminium et lesdits élé- fermée ; ments (67, 68) de forme générale circulaire com- 50 prennent de l'acier inoxydable. caractérisée en ce que ledit corps (12, 12a, 12b) comprend deux segments (12a, 12b) disposés 6. Soupape de EGR (10) selon la revendication 3, axialement bout à bout le long dudit axe (22 ; 22a, dans laquelle ladite gorge (28) est disposée dans 22c) dudit passage (20) délimité par une paroi et une nervure circulaire (80) qui s'étend autour dudit qui, en coopération, définissent une gorge (28 ; 80) 55 passage délimité par une paroi (20). ouverte radialement vers l'intérieur dans laquelle lesdits moyens d'étanchéité (26, 67, 68) sont dispo- 7. Soupape de EGR (10) selon une quelconque des sés, ladite gorge (28 ; 80) comprenant des surfaces revendications précédentes, comprenant en outre

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des moyens d'étanchéité (76) disposés radialement à l'extérieur de ladite gorge (28) pour établir une fer- meture étanche entre lesdits segments (12a, 12b) du corps de manière que les gaz d'échappement du moteur ne fuient hors dudit passage (20) délimité 5 par une paroi entre lesdits segments (12a, 12b) du corps.

8. Soupape de EGR (10) selon une quelconque des revendications précédentes, dans laquelle lesdits 10 moyens d'actionnement (16, 30, 30a, 38) comprennent un moteur couple rotatif (38) disposé à l'exté- rieur dudit passage (20) délimité par une paroi et ledit arbre d'actionnement (30, 30a) s'étend à partir dudit moteur couple rotatif (38) pour pénétrer dans 15 ledit passage (20) délimité par une paroi.

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