Exhaust flap valve

Abstract

Flap valve (10) for an exhaust system of an internal combustion engine comprising - a tubular housing (12), - a flap sail (14), - a valve shaft (16) by means of which the valve leaf (14) can be pivoted between an open position and a closed position about a pivot axis (20) in the housing (12), and - a first stop segment (22) which extends over a partial circumference of the housing (12) and against which the flap leaf (14) rests in the closed position, wherein the flap leaf (14) has a first and a second leaf section (28, 30) on opposite sides of the flap shaft (16) and a receiving section (32) which overlaps the flap shaft (16), wherein the flap valve (10) further comprises a shaft cover (34) which engages over the flap shaft (16) on the side of the flap leaf (14) facing away from the receiving section (32) and is fastened to the flap leaf (14), characterized by that the receiving section (32) has a recess (38) in the axial direction relative to the first sail section (28), into which the first stop segment (22) extends, that a radially extending cutting line (44) is formed in the valve leaflet (14) between the receiving section (32) and the first leaflet section (28), and that an opening stop (46) is formed on the recess (38), which in the open position rests against the first stop segment (22).

Description

[0001] The invention relates to a flap valve for an exhaust system of an internal combustion engine, comprising a tubular housing, a flap sail, a flap shaft, by means of which the flap sail can be pivoted between an open position and a closed position about a pivot axis in the housing, and a first stop segment which extends over a partial circumference of the housing and against which the flap sail rests in the closed position, wherein the flap sail has a first and a second sail section on opposite sides of the flap shaft and a receiving section which overlaps the flap shaft.

[0002] Such flap valves are used to regulate exhaust gas flow. Especially for flap valves that influence the acoustic behavior of the combustion engine or its exhaust system, it is important that the exhaust flow can be blocked as completely as possible by the housing in the closed position. In conventional flap valves with a receiving section produced by bending, sealing the flap valve against the housing in the area of ​​the transition between the receiving section and the valve sections is often problematic.

[0003] DE 10 2011 100 238 A1 relates to a butterfly valve for the exhaust system of an automobile, comprising a housing, a valve disc arranged in the housing, and a shaft that is attached to one side of the valve disc and extends continuously between two pivot bearings. The butterfly valve comprises a shaft cover that covers the shaft on the valve disc.

[0004] EP 3 263 856 A1 describes an exhaust flap, in particular for the exhaust flow of an internal combustion engine, comprising a flap tube, a flap cover supported inside the flap tube on a pivot shaft rotatable about a pivot axis, said flap cover having at least one flap vane, and a mounting area that at least partially surrounds the pivot shaft. A vane stop is provided on an inner circumferential area of ​​the flap tube in association with at least one flap vane. In at least one axial end area of ​​the mounting area, a recess is provided on the flap cover that accommodates a circumferential end area of ​​a vane stop.

[0005] DE 11 2010 005 713 T5 relates to a valve with a deformed circular shape such that a diameter in an axial direction perpendicular to a central rotation axis is longer than that in an axial direction parallel to the central rotation axis. A semicircular front surface on one side of the valve and a semicircular rear surface on the other side thereof, with the central rotation axis as a boundary, are in contact with the valve seat. Object of the invention

[0006] The object of the invention is to provide a particularly tightly closing exhaust flap valve. Description of the invention

[0007] This object is achieved according to the invention by a flap valve according to claim 1. The subclaims specify advantageous developments. The present invention also includes an internal combustion engine according to claim 17.

[0008] According to the invention, a flap valve is provided for an exhaust system of an internal combustion engine. The flap valve can be used to regulate the exhaust flow of the internal combustion engine.

[0009] The flap valve has a tubular housing. An exhaust gas flow from the combustion engine can be conducted through the housing. The housing typically has an at least approximately circular internal cross-section. In the vicinity of the flap leaflet, the internal cross-section of the housing is usually constant in the flow direction. In other words, the housing can be designed with a cylindrical internal cross-section.

[0010] The flap valve further comprises a flap leaf and a flap shaft. The flap leaf can be pivoted about a pivot axis within the housing between an open position and a closed position by means of the flap shaft. Within the housing, the flap shaft is typically circular and preferably has a constant diameter along the pivot axis. In the closed position, the flap leaf closes the interior cross-section of the housing. In the open position, the flap leaf exposes the interior cross-section, allowing the exhaust gas to flow through the housing.

[0011] For the description of the present invention, directional terms such as axial or radial refer to the pivot axis unless otherwise stated.

[0012] The flap valve further comprises a first stop segment. The first stop segment extends over a partial circumference of the housing. In other words, the first stop segment runs along the inner circumference of the housing over a certain circumferential area. The first stop segment is generally tightly connected to the housing. This can prevent leakage between the housing and the first stop segment. The first stop segment is typically formed in one piece. In special cases, the first stop segment can be formed from multiple parts. In the closed position, the flap leaflet rests against the first stop segment. In other words, the first stop segment defines the closed position. By the flap leaflet resting against the first stop segment in the closed position, leakage between the flap leaflet and the first stop segment can be at least largely reduced or preferably avoided.In other words, the valve leaflet can rest sealingly against the first stop segment.

[0013] The valve leaflet has a first and a second leaflet section on opposite sides of the valve shaft and a receiving section that overlaps the valve shaft. The receiving section is arranged between the first and the second leaflet section. The first and second leaflet sections serve to close the inner cross-section of the housing. The first or the second leaflet section can each be flat and preferably extend in a common plane, in particular wherein the common plane contains the pivot axis. The receiving section serves to attach the valve leaflet to the valve shaft. The receiving section typically lies directly against the valve shaft and can be connected to it, in particular by a material fit, preferably welded. The shape of the receiving section can correspond to an outer contour of the valve shaft.The receiving section can be at least approximately semicircular in cross-section. The valve leaflet is generally formed in one piece. The receiving section can be manufactured by plastic deformation of a flat blank for the valve leaflet. The first stop segment is arranged on the side of the receiving section—in the direction of flow through the housing. In the closed position, the first leaflet section of the valve leaflet rests against the first stop segment.

[0014] According to the invention, the receiving section has a recess in the axial direction relative to the first leaflet section. The recess can also be referred to as a notch. In the axial direction relative to the pivot axis, an outer contour of the valve leaflet in the region of the recess remains behind the outer contour of the first leaflet section. In other words, the first leaflet section extends in the axial direction beyond the region of the receiving section provided with the recess. The recess can be formed by a recess in the (axial) outer contour of the valve leaflet.

[0015] According to the invention, it is further provided that the first stop segment extends into the recess. In the closed position of the flap leaf, the inner cross-section of the housing can thus be at least largely, preferably completely, closed. The recess allows the first stop segment to be brought particularly close to the flap shaft. The recess eliminates production-related roundings of the flap leaf, which would prevent the inner cross-section of the housing from being closed and, in particular, prevent the flap leaf from sealing against the first stop segment. By the first stop segment extending into the recess according to the invention, a particularly tightly closing flap valve can be obtained. In the closed position of the flap valve, the inner cross-section of the housing can be completely covered when viewed along a flow direction through the housing.The flap valve according to the invention is therefore particularly suitable for acoustic applications in which an exhaust gas flow through the housing should be blocked as completely as possible.

[0016] The recess typically extends to the first leaflet section or is directly adjacent to the first leaflet section. The recess can extend from the first leaflet section to the second leaflet section. The recess then directly borders the first leaflet section and the second leaflet section. The axial depth of the recess can be constant between the leaflet sections. The valve leaflet can then be mirror-symmetrical to a plane containing the pivot axis. Alternatively, the axial depth of the recess can be variable between the leaflet sections, in particular to form an opening stop.

[0017] Particularly preferably, the receiving section has an axial recess at each end relative to the first leaflet section, into which the first stop segment extends. The advantageous sealing effect of the first stop segment extending into the recess can thus be achieved at both axial end regions of the valve leaflet. One end section of the first stop segment protrudes into each of the two recesses. The first stop segment typically extends by almost 180° around the inner circumference of the housing.

[0018] A radially running cutting line is formed in the valve leaflet between the receiving section and the first leaflet section. Axially inward with respect to the cutting line, the valve leaflet can be bent up to form the receiving section. Axially outward with respect to the cutting line, the first leaflet section can extend as far as the valve shaft and in particular lie tightly against the valve shaft. In other words, the first leaflet section can extend axially next to the receiving section right up to the valve shaft. The cutting line enables these designs. In particular, the first leaflet section and the receiving section can be directly adjacent to one another at the cutting line. As a result of the cutting line, the valve leaflet can thus advantageously be designed for a particularly tight connection to the valve shaft. The cutting line preferably does not create a gap between the first leaflet section and the receiving section.Typically, the first sail section and the receiving section touch each other along the cutting line.

[0019] A further radially running cutting line can be formed in the valve leaflet between the receiving section and the second leaflet section. Axially inward with respect to the further cutting line, the valve leaflet can be bent up to form the receiving section. Axially outward with respect to the further cutting line, the second leaflet section can extend as far as the valve shaft and in particular lie tightly against the valve shaft. In other words, the second leaflet section can extend axially next to the receiving section right up to the valve shaft. The further cutting line enables these designs. In particular, the second leaflet section and the receiving section can be directly adjacent to one another at the further cutting line. As a result of the further cutting line, the valve leaflet can thus be advantageously designed for a particularly tight connection to the valve shaft.The further cutting line preferably does not create a gap between the second sail section and the receiving section. Typically, the second sail section and the receiving section touch each other along the further cutting line.

[0020] Preferably, the first stop segment extends in the recess up to the flap shaft. This further reduces leakage flow in the closed position of the flap valve. The radial distance of the first stop segment from the flap shaft can be at most 0.5 mm, preferably at most 0.3 mm, and particularly preferably at most 0.2 mm.

[0021] The first stop segment can extend axially up to the receiving section in the area of ​​the recess. This contributes to further improving the closing effect of the flap valve. The axial distance between the receiving section and the first stop segment can be a maximum of 1.0 mm, preferably a maximum of 0.7 mm, and particularly preferably a maximum of 0.5 mm. These distances allow for a thermally induced change in length in the axial direction without the valve leaflet becoming jammed against the first stop segment.

[0022] The valve shaft can be mounted on the housing. For this purpose, a bearing cup for accommodating a bearing, in particular a plain bearing, preferably with a graphite bearing ring, can be provided on the housing. Typically, two bearing cups are provided on axially opposite sides of the housing. The bearing cup can be open on one or both sides in the axial direction. The valve shaft can extend into the bearing cup or extend through it accordingly.

[0023] A bearing cup for the valve shaft can extend into the housing. This is advantageous for manufacturing reasons. Furthermore, the section of the bearing cup that extends into the housing can help seal the inner cross-section of the housing when the valve leaf is closed. Preferably, the first stop segment rests against the bearing cup. This can further improve the sealing of the valve in the closed position.

[0024] The axial end contour of the valve leaflet preferably runs in a plane orthogonal to the pivot axis. In the area of ​​the recess, the outer contour of the valve leaflet remains behind the plane of the end contour in the axial direction.

[0025] Particularly preferably, the axial end contour of the valve leaflet is configured to correspond to a section of a bearing cup that projects into the housing. This allows a gap between the bearing cup and the valve leaflet to be reduced as much as possible. The remaining gap is preferably covered by the first stop segment and, if appropriate, a second stop segment. The axial distance between the bearing cup and the valve leaflet can be at most 1.0 mm, preferably at most 0.7 mm, particularly preferably at most 0.5 mm. At these distances, a thermally induced change in length in the axial direction is enabled without the valve leaflet jamming against the bearing cup.

[0026] An opening stop is formed on the recess, which rests against the first stop segment in the open position. The open position is thus defined by the engagement of the opening stop of the flap leaf with the first stop segment. This enables an integrated design of the flap valve without additional components for defining the open position. The opening stop is typically formed by an edge region of the recess on the receiving section that runs in the axial direction.

[0027] The flap valve can have a second stop segment against which the flap leaflet rests with the second leaflet section in the closed position. The second stop segment can seal the flap leaflet against the housing in the closed position on the side of the flap shaft opposite the first stop segment. The second stop segment is arranged on the side of the flap leaflet facing away from the receiving section, as seen in the flow direction through the housing. The first and second stop segments therefore rest on the flap leaflet on different sides (in the flow direction) in the closed position. The second stop segment typically extends over part of the circumference of the housing. In other words, the second stop segment runs along the inner circumference of the housing over a certain circumferential area. The second stop segment is generally tightly connected to the housing.This prevents leakage between the housing and the second stop segment. By ensuring that the valve leaf rests against the second stop segment in the closed position, leakage between the valve leaf and the second stop segment can be avoided or at least largely reduced. In other words, the valve leaf can form a sealing contact with the second stop segment. The second stop segment is typically formed in one piece. In special cases, the second stop segment can be formed in multiple parts.

[0028] Preferably, the second stop segment extends to the valve shaft at both ends. This can further improve the sealing effect of the second stop segment. The radial distance of the second stop segment from the valve shaft can be at most 0.5 mm, preferably at most 0.3 mm, and particularly preferably at most 0.2 mm.

[0029] Advantageously, the first and second stop segments are identical in design. This allows for cost-effective production of the flap valve. Preferably, the two stop segments are arranged mirror-symmetrically to the pivot axis in the housing. This promotes uniform contact of the valve leaflet with the two stop segments, especially when the two leaflet sections extend in a common plane. The stop segments are then offset from each other in the flow direction.

[0030] The flap valve has a shaft cover that engages over the flap shaft on the side of the flap leaflet facing away from the receiving section. The shaft cover can be used to fasten the flap leaflet to the flap shaft. The shaft cover is fastened to the flap leaflet, preferably by a material fit. In particular, the shaft cover and the flap leaflet can be welded together. The shaft cover is preferably fastened to the first and second leaflet sections. Alternatively or additionally, the shaft cover can be fastened to the receiving section. By means of the shaft cover, the flap leaflet can be held force-fit to the flap shaft (in the axial direction and in the circumferential direction). The shaft cover can simplify the fastening of the flap leaflet to the flap shaft; in particular, a direct material fit connection between the flap leaflet and the flap shaft can be dispensed with.

[0031] The shaft cover is preferably shorter in the axial direction than the clearance between the end sections of the second stop segment. This allows the second stop segment to extend to the valve shaft at both ends.

[0032] The flap valve may have an actuator for pivoting the flap shaft. The actuator may be an electric or pneumatic actuator. The actuator may include an actuator receptacle, particularly in the form of an actuator housing, by means of which the actuator is attached to the housing.

[0033] The actuator is preferably connected to the valve shaft via a coupling preloaded in the axial direction. This axial preload allows the valve shaft to be held in a backlash-free position on an axial bearing. The coupling is advantageously designed for a rotational, backlash-free coupling of the valve shaft to the actuator. This allows the valve leaf to be set to defined intermediate positions (between the open and closed positions).

[0034] The components of the flap valve, in particular the housing, the flap leaf, the shaft cover, the first stop segment, the second stop segment, and / or the flap shaft, can be made of steel, preferably stainless steel. This allows the required temperature resistance of the flap valve to be maintained.

[0035] The present invention further includes an internal combustion engine with an exhaust system having a flap valve according to one of the preceding claims. An exhaust gas flow from the internal combustion engine can be directed through the housing of the flap valve. The flow through the flap valve can be varied by pivoting the flap leaf. The flap valve according to the invention enables an almost complete, or preferably complete, blockage of the exhaust gas flow through the housing of the flap valve. This is particularly advantageous with regard to the acoustic behavior of the internal combustion engine or its exhaust system.

[0036] Further advantages of the invention will become apparent from the description and the drawings. The features mentioned above and those further detailed below can be used individually or in combination in any suitable way. The embodiments shown and described are not intended to be exhaustive, but rather are exemplary in nature for describing the invention. Detailed description of the invention and drawing

[0037] The invention is illustrated in the drawing and explained in more detail using exemplary embodiments. They show: Fig. 1 a flap valve according to the invention with a flow-through housing in which a flap leaf is held on a flap shaft so as to be rotatable about a pivot axis, wherein the flap leaf has a receiving section which overlaps the flap shaft and has a recess relative to a first leaf section, and wherein a first stop segment, against which the first leaf section rests in the illustrated closed position, extends into the recess up to the flap shaft, in a schematic view looking along a flow direction of the housing; Fig. 2 the flap valve of Fig. 1, in a schematic view with opposite Fig. 1 opposite view, showing a second stop segment and a shaft cover of the flap valve; Fig. 3 a flap leaflet held on a flap shaft for a flap valve according to the invention and two stop segments for engagement with opposing leaflet sections of the flap leaflet, in a schematic perspective view; Fig. 4 the arrangement of Fig. 3 in a further schematic perspective view; Fig. 5 a valve leaflet with two leaflet sections between which a receiving section for a valve shaft is formed, wherein the receiving section has an axial recess, for a flap valve according to the invention, in a schematic perspective view; Fig. 6 the valve leaflet of Fig. 5 in a further schematic perspective view; Fig. 7 the valve leaflet of Fig. 5 in a schematic plan view; Fig. 8 the valve leaflet of Fig. 5 in a schematic bottom view; Fig. 9 a flap sail for a flap valve according to the invention, which is attached to a flap shaft by means of a shaft cover; Fig. 10 shows a further flap leaf with a flap shaft for a flap valve according to the invention, wherein a recess in a receiving section extends from a first leaf section to a second leaf section.

[0038] Fig. Figure 1 shows a flap valve 10. The flap valve 10 has a tubular housing 12. The housing 12 has a circular internal cross-section. An exhaust gas flow from a combustion engine (not shown in detail) can be directed through the housing 12. For this purpose, the housing 12 can be integrated into an exhaust system of the combustion engine (also not shown in detail).

[0039] The flap valve 10 has a flap leaf 14. The flap leaf 14 is pivotably mounted in the housing 12. For this purpose, the flap leaf 14 is held on a flap shaft 16. The flap shaft 16 is mounted in two bearing cups 18 on the housing 12 for rotation about a pivot axis 20.

[0040] In Fig. 1, the flap valve 10 is in a closed position. In the closed position, the internal cross-section of the housing 12 is blocked, in particular by the flap leaf 14. Flow through the housing 12 is therefore not possible or at least largely restricted.

[0041] The flap valve 10 has a first stop segment 22. The flap valve 10 also has a second stop segment 24, see Fig. 2. The two stop segments 22, 24 are arranged on opposite sides (in the flow direction) of the valve leaf 14. In the closed position, the valve leaf 14 rests sealingly against the two stop segments 22, 24. The two stop segments 22, 24 are each sealingly inserted into the housing 12. For fixing to the housing 12, the stop segments 22, 24 can each have projections 26, see Fig. 3 and Fig. 4. The two stop segments 22, 24 are constructed identically to one another and are arranged mirror-symmetrically with respect to the pivot axis 20 in the housing 12.

[0042] The flap leaflet 14 has a first leaflet section 28, a second leaflet section 30 and a receiving section 32, see also Fig. 5 to 9. The first and second leaflet sections 28, 30 are arranged on opposite sides of the flap leaflet 14 with respect to the pivot axis 20. The receiving section 32 is arranged between the two leaflet sections 28, 30. The receiving section 32 connects the two leaflet sections 28, 30 to one another. The receiving section 32 serves to receive the flap shaft 16. For this purpose, the receiving section 32 is curved in a semicircular cross-section. Thus, the receiving section 32 is adapted to an outer contour of the flap shaft 16. The receiving section 32 can bear directly against the flap shaft 16.

[0043] A shaft cover 34 can be provided to fasten the flap sail 14 to the flap shaft 16, see Fig. 2 and Fig. 9. The shaft cover 34 is attached to the flap leaf 14. The shaft cover 34 can, in particular, be welded to the two leaf sections 28, 30.

[0044] The valve shaft 16 can be clamped between the receiving section 32 and the shaft cover 34, so that the valve leaf 14 is held in a force-locking manner on the valve shaft 16 in the axial direction and with respect to rotations about the valve shaft 16. The shaft cover 34 is shorter in the axial direction than a clear width between end sections 36 of the second stop segment 24, see Fig. 2. The end sections 36 can extend straight in the radial direction.

[0045] The valve leaflet 14 has an axial recess 38 on the receiving section 32. In the illustrated valve leaflet 14, an axial recess 38 is formed at each end of the receiving section 32 in the axial direction. In the area of ​​the recess 38, an outer contour of the receiving section 32 remains behind the outer contour of the first leaflet section 28 and, in this case, also of the second leaflet section 30 in the axial direction. The recess 38 is designed here as a notch in the valve leaflet 14. The recess 38 provides radial access to the valve shaft 16.

[0046] The first stop segment 22 extends into the recesses 38, compare Fig. 1, Fig. 3 and Fig. 4. The ends of the first stop segment 22 and the receiving section 32 near the shaft have the same radial distance from the pivot axis 20. Here, end sections 40 of the first stop segment 22 extend radially up to the valve shaft 16. In the axial direction, the end sections 40 of the first stop segment 22 bear sealingly against sections of the bearing cups 18 that extend into the housing 12, see Fig. 1. The end sections 40 can extend straight in the radial direction.

[0047] The end sections 36 of the second stop segment 24 can also sealingly abut the sections of the bearing cups 18 projecting into the housing 12, compare Fig. 2. The end sections 36 here also extend in the radial direction up to the valve shaft 16.

[0048] In the axial direction, the end sections 40 of the first stop segment 22 extend over almost the entire depth of the recesses 38, compare Fig. 1. In other words, the end sections 40 extend from the bearing cups 18 to the recessed area of ​​the receiving section 32, leaving only a small gap to compensate for thermal length changes.

[0049] An axial end contour 42 of the leaflet sections 28, 30 of the valve leaflet 14 can run in a plane orthogonal to the pivot axis 20, compare in particular Fig. 7 and Fig. 8. In the area of ​​the recesses 38, the outer contour of the receiving section 32 remains behind the respective end contour 42 in the axial direction. The recesses 38 form axial depressions in the outer contour of the valve leaflet 14. In other words, the outer contour of the valve leaflet 14 is concave in the area of ​​the recesses 38. Otherwise, the outer contour of the valve leaflet 14 is generally convex.

[0050] The linearly extending axial end contours 42 can correspond to the axial end regions of the sections of the bearing cups 18 that project into the housing 12. The valve leaflet 14 can thus be brought particularly close to the bearing cups 18. Remaining gaps between the end contours 42 and the bearing cups 18 are covered in the closed position by the end sections 40, 36 of the two stop segments 22, 24.

[0051] In the representation according to Fig. 7, the first stop segment 22 would be arranged above the plane of the drawing on the first sail section 28. The second stop segment 24 would be arranged correspondingly below the plane of the drawing under the second sail section 30.

[0052] In the representation according to Fig. 8, the first stop segment 22 would be arranged below the plane of the drawing under the first sail section 28. The second stop segment 24 would be arranged correspondingly above the plane of the drawing on the second sail section 30.

[0053] The first sail section 28 and the receiving section 32 can be separated from each other in the axial direction adjacent to the recesses 38 by a cutting line 44, see in particular Fig. 5 to 8. Axially outside the cutting lines 44, the first sail section 28 extends directly to the valve shaft 16, compare Fig. 4. Between the cutting lines 44, the receiving section 32 is bent upwards relative to the first leaf section 28. The cutting line 44 makes it possible, on the one hand, to create a sufficiently large bending radius in the transition area between the first leaf section 28 and the receiving section 32 and, on the other hand, to bring the first sealing section 28 adjacent to the recesses 38 right up to the flap shaft 16. The areas of the first leaf section 28 that touch the flap shaft 16 make it possible to create a continuous contact between the first leaf section 28 and the first stop segment 22 in the circumferential direction. In particular, the first leaf section 28 can also bear directly against the flap shaft 16 at the end sections 40 of the first stop segment 22 that project into the recesses 38.

[0054] Compared to the Fig. 1 and Fig. In addition to the closed position shown in Figure 2, the flap leaf 14 can also be moved into an open position rotated by approximately 90°. For this purpose, the flap leaf 14 is rotated about the pivot axis 20 by means of the flap shaft 16.

[0055] In the illustrated embodiment of the flap valve 10, the open position is defined by an opening stop 46. The opening stop 46 is formed on the recess 38, here on both recesses 38. The opening stop 46 limits the recesses 38 in the circumferential direction with respect to the pivot axis 20 and the flap shaft 16. The opening stop 46 is formed in each case by an axially extending edge region of the recesses 38. In other words, the edge regions of the recesses 38 forming the opening stop 46 extend parallel to the pivot axis 20. In the open position, the opening stops 46 bear against the first stop segment 22, namely against its end sections 40 extending into the recesses 38.

[0056] An actuator (not shown in detail) is provided to pivot the flap leaf 14 between the closed and open positions by means of the flap shaft 16. The actuator can be attached to the housing 12 of the flap valve 10 by means of an actuator receptacle 48, here in the form of an actuator housing. See Fig. 1. A coupling (here concealed by the actuator mount 48) can be provided to couple the actuator to the valve shaft 16. The coupling is preferably preloaded in the axial direction to compensate for changes in length and to hold the valve shaft 16 in axial contact with an axial bearing housed in one of the bearing cups 18.

[0057] The aforementioned design features result in a flap valve 10 that is particularly capable of sealing the internal cross-section of the housing 12 when the flap leaf 14 is in the closed position. For this purpose, the flap leaf 14 is provided with recesses 38 adjacent to the flap shaft 16, into which recesses the first stop segment 22 projects. The two stop segments 22, 24 rest on the outside of the housing 12 and the bearing cups 18 in a sealing manner. In the closed position, the flap leaf 14, with its two leaf sections 28, 30, rests in an axially sealing manner on the stop segments 22 and 24, respectively. The recesses 38 make it possible to move the first stop segment 22 adjacent to the bearing cups 18 up to the flap shaft 16 in order to seal the internal cross-section of the housing 12 in this area as well.The recesses 38 can be limited in the circumferential direction with respect to the flap shaft on the one hand by an opening stop 46 and on the other hand by a region of the first sail section 28 extending directly up to the flap shaft 16.

[0058] Fig. 10 shows another flap leaflet 14. The flap leaflet 14 is held on a flap shaft 16. The flap leaflet 14 of Fig. 10 corresponds in structure and function essentially to the valve leaflet 14 described above according to the Fig. 1 to 9. The differences are described in particular below; otherwise, reference is made to the preceding description.

[0059] The valve leaflet 14 has a first leaflet section 28 and a second leaflet section 30. The first leaflet section 28 and the second leaflet section 30 are connected to each other by a receiving section 32. The valve leaflet 14 is formed as a single piece. The receiving section 32 is bent upwards relative to the two leaflet sections 28, 30 and overlaps the valve shaft 16.

[0060] A recess 38 is formed at each axial end of the receiving section 32. The recesses 38 each extend from the first sail section 28 to the second sail section 30, here with a constant axial depth. Due to the recesses 38, the receiving section 32 remains behind both the first sail section 28 and the second sail section 30 in the axial direction. An axial length of the receiving section 28 is smaller than a distance (measured parallel to the pivot axis 20) between opposite axial end contours 42 of the sail sections 28, 30.

[0061] Between the receiving section 32 and the first leaflet section 28, radially extending cutting lines 44 are formed at the axial ends of the receiving section 32. Likewise, between the receiving section 32 and the second leaflet section 30, further radially extending cutting lines 45 are formed at the axial ends of the receiving section 32. In the region of the cutting lines 44, 45, the receiving section 32 and the leaflet sections 28, 30 directly adjoin one another, in particular, they touch one another. Axially outside the cutting lines 44, 45, the leaflet sections 28, 30 extend directly to the valve shaft 16. List of reference symbols 10 flap valve 12 housings 14 flap sails 16 valve shaft 18 storage pots 20 swivel axis 22 first stop segment 24 second stop segment 26 projections 28 first sailing section 30 second sailing section 32 Recording section 34 Shaft cover 36 end sections of the second stop segment 24 38 Withdrawal 40 end sections of the first stop segment 22 42 axial final contour 44 Cutting line 45 further cutting line 46 Opening stop 48 Actuator holder

Claims

[1] Flap valve (10) for an exhaust system of an internal combustion engine comprising - a tubular housing (12), - a flap sail (14), - a valve shaft (16) by means of which the valve leaf (14) can be pivoted between an open position and a closed position about a pivot axis (20) in the housing (12), and - a first stop segment (22) which extends over a partial circumference of the housing (12) and against which the flap leaf (14) rests in the closed position, wherein the flap leaf (14) has a first and a second leaf section (28, 30) on opposite sides of the flap shaft (16) and a receiving section (32) which overlaps the flap shaft (16), wherein the flap valve (10) further comprises a shaft cover (34) which engages over the flap shaft (16) on the side of the flap leaf (14) facing away from the receiving section (32) and is fastened to the flap leaf (14), characterized by , that the receiving section (32) has a recess (38) in the axial direction relative to the first sail section (28), into which the first stop segment (22) extends, that a radially extending cutting line (44) is formed in the valve leaflet (14) between the receiving section (32) and the first leaflet section (28), and that an opening stop (46) is formed on the recess (38), which in the open position rests against the first stop segment (22). [2] Flap valve (10) according to claim 1, characterized by that the recess (38) extends from the first sail section (28) to the second sail section (30). [3] Flap valve (10) according to claim 1 or 2, characterized by that the receiving section (32) has at both ends an axial recess (38) relative to the first sail section (28), into which the first stop segment (22) extends. [4] Flap valve (10) according to one of the preceding claims, characterized by that a further radially extending cutting line (45) is formed in the valve leaflet (14) between the receiving section (32) and the second leaflet section (30). [5] Flap valve (10) according to one of the preceding claims, characterized by that the first stop segment (22) extends in the recess (38) up to the flap shaft (16). [6] Flap valve (10) according to one of the preceding claims, characterized by that the first stop segment (22) in the region of the recess (38) extends in the axial direction up to the receiving section (32). [7] Flap valve (10) according to one of the preceding claims, characterized by that a bearing cup (18) for the flap shaft (16) projects into the housing (12), preferably wherein the first stop segment (22) bears against the bearing cup (18). [8] Flap valve (10) according to one of the preceding claims, characterized by that the valve leaflet (14) has an axial end contour (42) which runs in a plane orthogonal to the pivot axis (20), preferably wherein the end contour (42) is designed to correspond to a section of a bearing cup (18) projecting into the housing (12). [9] Flap valve (10) according to one of the preceding claims, characterized by that the opening stop (46) is formed by an edge region of the recess (38) on the receiving section (32) running in the axial direction. [10] Flap valve (10) according to one of the preceding claims, characterized by that the flap valve (10) has a second stop segment (24) against which the flap leaf (14) rests with the second leaf section (30) in the closed position. [11] Flap valve (10) according to claim 10, characterized bythat the second stop segment (24) extends at both ends to the flap shaft (16). [12] Flap valve (10) according to claim 10 or 11, characterized by that the first and the second stop segment (22, 24) are of identical construction and are preferably arranged mirror-symmetrically to the pivot axis (20) in the housing (12). [13] Flap valve (10) according to one of the preceding claims, characterized by that the shaft cover (34) is attached to the first and second sail sections (28, 30). [14] Flap valve (10) according to one of claims 10 to 12 and according to claim 13, characterized by that the shaft cover (34) is shorter in the axial direction than a clear width between end sections (36) of the second stop segment (24). [15] Flap valve (10) according to one of the preceding claims, further comprising an actuator for pivoting the flap shaft (16). [16] Flap valve (10) according to claim 15, characterized by that the actuator is connected to the flap shaft (16) via a coupling prestressed in the axial direction. [17] Internal combustion engine with an exhaust system having a flap valve (10) according to one of the preceding claims.

Images