Flap Device

Abstract

A flap device for a motor vehicle comprises a flap housing that can be flowed through by a gas flow; a flap shaft that is rotatably supported about an axis of rotation in the flap housing and that supports a flap for blocking, directing or throttling the gas flow; and an actuating drive for rotating the flap shaft. The actuating drive is in a drive-effective connection with the flap shaft via a coupling, wherein the coupling comprises two separate coupling parts that can be axially plugged into one another and that, in the state plugged into one another, can be brought into engagement with one another in a form-fitting manner with respect to at least one direction of rotation, and wherein the coupling comprises a spring element that is inserted under an axial preload between the coupling parts plugged into one another, wherein the coupling parts have respective locking sections that, on an axial plugging into one another of the coupling parts, can be moved past one another and can be brought into an engaging-behind engagement with respect to at least one axial direction by a mutual rotation of the coupling parts plugged into one another with respect to the axis of rotation.

Claims

1. A flap device for a motor vehicle, said flap device comprising a flap housing that can be flowed through by a gas flow; a flap shaft that is rotatably supported about an axis of rotation in the flap housing and that supports a flap for blocking, directing or throttling the gas flow; and an actuating drive for rotating the flap shaft, wherein the actuating drive is in a drive-effective connection with the flap shaft via a coupling, wherein the coupling comprises two separate coupling parts that can be axially plugged into one another and that, in the state plugged into one another, can be brought into engagement with one another in a form-fitting manner with respect to at least one direction of rotation, and wherein the coupling comprises a spring element that is inserted under an axial preload between the coupling parts plugged into one another, and wherein the coupling parts have respective locking sections that, on an axial plugging into one another of the coupling parts, can be moved past one another and can be brought into an engaging-behind engagement with respect to at least one axial direction by a mutual rotation of the coupling parts plugged into one another with respect to the axis of rotation.

2. The flap device in accordance with claim 1, wherein the flap device is an exhaust gas flap device.

3. The flap device in accordance with claim 1, wherein the spring element preloads the coupling parts against one another in a tangential direction.

4. The flap device in accordance with claim 1, wherein one of the coupling parts is a flap-side coupling part and the other coupling part is a drive-side coupling part, with the flap-side coupling part being fixedly connected to the flap shaft and/or the drive-side coupling part being configured for a releasable connection to an output shaft of the actuating drive.

5. The flap device in accordance with claim 4, wherein the drive-side coupling part can be coupled to an output shaft of the actuating drive by means of a plug-in connection.

6. The flap device in accordance with claim 5, wherein the drive-side coupling part has at least one recess into which a plug-in projection arranged at the output shaft of the actuating drive can be plugged.

7. The flap device in accordance with claim 6, wherein the drive-side coupling part has an arrangement of at least two recesses into which respective plug-in projections arranged at the output shaft of the actuating drive can be plugged.

8. The flap device in accordance with claim 7, wherein the drive-side coupling part has an arrangement of four recesses.

9. The flap device in accordance with claim 7, wherein the recesses define a rotationally symmetrical pattern.

10. The flap device in accordance with claim 6, wherein the or each plug-in projection has a cone.

11. The flap device in accordance with claim 1, wherein one of the coupling parts has an axial projection extending in an axial direction as a locking section and the other coupling part has a radial projection extending in a radial direction as a locking section, with a contact surface extending in a tangential direction for the radial projection being formed at the axial projection.

12. The flap device in accordance with claim 11, wherein the contact surface is arranged in a region of the axial projection that is a central region with respect to the axial direction.

13. The flap device in accordance with claim 11, wherein a run-on slope is formed at the axial projection, along which run-on slope the radial projection can slide on a plugging of the coupling parts into one another.

14. The flap device in accordance with claim 1, wherein the actuating drive is fastened to the flap housing by means of a holder that has a leadthrough for an output shaft of the actuating drive.

15. The flap device in accordance with claim 14, wherein the leadthrough has a passage surface that is smaller than an axial cross-sectional surface of the coupling.

16. The flap device in accordance with claim 14, wherein the leadthrough has a passage surface that is smaller than an axial cross-sectional surface of the coupling parts.

17. The flap device in accordance with claim 1, wherein the coupling parts are designed as stamped/bent parts.

18. The flap device in accordance with claim 1, wherein at least one component of the actuating drive is at least partly produced from plastic.

19. The flap device in accordance with claim 18, wherein the at least one component of the actuating drive comprises a housing of the actuating drive and/or an output shaft of the actuating drive.

Description

[0029] The invention will be described in the following by way of example with reference to the enclosed drawings.

[0030] FIG. 1 shows a perspective representation of a flap device in accordance with the invention;

[0031] FIG. 2 shows a coupling of the flap device in accordance with FIG. 1 in a perspective representation;

[0032] FIG. 3 shows the coupling in accordance with FIG. 2 from a different viewing direction; and

[0033] FIGS. 4A-4D show the coupling in accordance with FIG. 2 at various stages during the assembly.

[0034] The flap device 10 shown in FIG. 1 comprises a flap 11, which is rotatably supported about an axis of rotation 14 in a flap housing 13, and an electric actuator as an actuating drive 15 for rotating the flap 11. The flap 11 is designed such that it blocks, throttles or releases a gas flow guided through the flap housing 13 depending on the rotational position. In the embodiment shown, the flap housing 13 is of a tubular design. The flap device 10 can in particular be configured as an exhaust flap device for the exhaust train of a motor vehicle.

[0035] The actuating drive 15 is fastened to the flap housing 13 by means of a holder 17. A base surface 18 of the holder 17 located between the actuating drive 15 and the flap housing 13 here effects a thermal shielding of the actuating drive 15 from the flap housing 13. The flap housing 13 and the holder 17 are preferably produced from a heat-resistant metal.

[0036] An output shaft of the actuating drive 15, which is not visible in FIG. 1 and is guided by the base surface 18 of the holder 17, transmits a torque to a flap shaft 21 connected to the flap 11 by means of a coupling 19 shown in more detail in FIGS. 2 and 3.

[0037] The coupling 19 comprises a flap-side coupling part 23 that is rotationally fixedly connected to the flap shaft 21, for example welded thereto. Furthermore, the coupling 19 comprises a drive-side coupling part 25. The two coupling parts 23, 25 are produced from sheet metal as stamped/bent parts and have respective plate-like support sections 27, 28 that extend transversely to the flap shaft 21. A helical spring 29 is arranged between the two coupling parts 23, 25 and is supported in the axial direction at the support sections 27, 28. The helical spring 29 has two limbs 31, 32 which can be pivoted relative to one another and by means of which the helical spring 29 can be elastically twisted.

[0038] The flap-side coupling part 23 has a wall section 33 that projects from the periphery of the support section 27 in the axial direction and, together with the support section 27, forms a cup-like receiver for the helical spring 29. A recess 35 through which a first limb 31 of the helical spring 29 is guided, as shown, is formed in the wall section 33. The flap-side coupling part 23 further has two mutually oppositely disposed radial projections 37 (FIG. 3) that project in the radial direction from the wall section 33.

[0039] The drive-side coupling part 25 has a holding projection 39 that projects from the periphery of the support section 28 in the axial direction. As can be seen in FIG. 3, a limb run-on slope 41 is provided at the holding projection 39. The second limb 32 of the helical spring 29 is supported at the holding projection 39 in the tangential direction.

[0040] Furthermore, two axial projections 45 are provided at the drive-side coupling part and extend from the periphery of the support section 28 in the axial direction. In the embodiment shown, the axial projections 45 are arranged radially in opposite directions. A radial projection run-on slope 47 is formed at each of the axial projections 45. Viewed in an axial direction facing away from the flap 11 (FIG. 1), behind the radial projection run-on slopes 47, respective steps are formed at the axial projections 45 that form contact surfaces 49 extending in the tangential direction for the radial projections 37. Tangentially adjacent to the axial projections 45, additional axial projections 51 extend from the support section 28 in the axial direction.

[0041] The support section 28 of the drive-side coupling part 25 has an arrangement of four recesses 55 into which respective plug-in projections arranged at the output shaft, not shown, of the actuating drive 15 can be plugged. The recesses 55 define a rotationally symmetrical pattern, here by way of example a cloverleaf-like pattern. By means of the recesses 55 and the associated plug-in projections, the drive-side coupling part 25 can be releasably coupled to the output shaft of the actuating drive 15.

[0042] The assembly of the coupling 19 will be described in the following with further reference to FIGS. 4A-4D. First, the coupling parts 23, 25 are separated from one another (FIG. 4A). The flap-side coupling part 23 is already fastened to the flap shaft 21, while the drive-side coupling part 25 is not yet connected to the actuating drive 15, i.e. is loose. The helical spring 29 is inserted into the cup-like receiver formed at the flap-side coupling part 23, and indeed such that the first limb 31 engages into the recess 35 and is thus fixedly held.

[0043] Then, the drive-side coupling part 25 is moved in the axial direction toward the flap-side coupling part 23, wherein the second limb 32 of the helical spring 29 enters into contact with the limb run-on slope 41 and the radial projections 37 enter into contact with the radial projection run-on slopes 47 (FIG. 4B). During a subsequent plugging together of the coupling parts 23, 25, the radial projections 37 slide along the radial projection run-on slopes 47. Equally, the second limb 32 of the helical spring 29 slides along the limb run-on slope 41. The second limb 32 is hereby rotated with respect to the fixedly held first limb 31. The helical spring 29 is thus twisted and preloads the drive-side coupling part 25 relative to the flap-side coupling part 23 in the tangential direction.

[0044] On a further axial movement of the drive-side coupling part 25, the radial projections 37 acted on by the torsional stress snap into the respective free spaces behind the radial projection run-on slopes 47 (FIG. 4C). The drive-side coupling part 25 is now securely held at the flap-side coupling part 23 since the radial projections 37 are engaged behind in the axial direction by the contact surfaces 49. Thus, the axial projections 45 and the radial projections 37 that can be brought into engagement therewith form locking sections that can be moved past one another on an axial plugging into one another of the coupling parts 23, 25 and that can be brought into a form-fitting engagement by a mutual rotation of the coupling parts 23, 25 plugged into one another.

[0045] The drive-side coupling part 25 can thus be released to mount the flap shaft 21 together with the coupling 19 at the flap housing 13 (FIG. 1). After the assembly of the flap shaft 21 and the coupling 19, the holder 17 is fastened to the flap housing 21.

[0046] Finally, the actuating drive 15 is attached to the holder 17, wherein the output shaft or a transmission component rotationally fixedly connected thereto are guided through a leadthrough 60 of the base surface 18 of the holder 17 shown in FIG. 4D and are plugged onto the drive-side coupling part 25. Here, the preferably conical plug-in projections enter the recesses 55 (FIG. 2) and provide a friction-locked and form-fitting connection of the output shaft to the drive-side coupling part 25. In the course of this plug-in process, the helical spring 29 is clamped between the two support sections 27, 28 and is thus axially pressed together, wherein the radial projections 37 move away from the contact surfaces 49 (FIG. 4D).

[0047] In the end position, the helical spring 29 is therefore preloaded both axially and tangentially. The tangential preload in this respect has the effect that the radial projections 37 are pressed against respective flanks of the axial projections 45. Such a small-area contact supports a thermal decoupling of the two coupling parts 23, 25 and furthermore eliminates a noise-generating play.

[0048] The thermal shielding of the actuating drive 15 is improved in that the leadthrough 60 is just large enough for the output shaft. If the drive-side coupling part 25 or the entire coupling 19 were preassembled at the actuating drive 15, the leadthrough 60 would, in contrast, have to be large enough for the much larger cross-sectional surface of the drive-side coupling part 25. It has been shown that in a flap device 10 in accordance with the invention, due to the improved thermal shielding, one or more components of the actuating drive 15 can be produced from plastic, which enables a considerable reduction in the weight and the manufacturing costs.

[0049] It is understood that, at the coupling parts 23, 25, differently designed locking sections can also be provided that can be moved past one another on an axial plugging into one another of the coupling parts 23, 25 and that can be brought into an engaging-behind engagement with respect to at least one axial direction by a mutual rotation of the coupling parts 23, 25 plugged into one another with respect to the axis of rotation 14. For example, stepped grooves and pins or brackets moving into them could be provided as locking sections.

REFERENCE NUMERAL LIST

[0050] 10 flap device [0051] 11 flap [0052] 13 flap housing [0053] 14 axis of rotation [0054] 15 actuating drive [0055] 17 holder [0056] 18 base surface [0057] 19 coupling [0058] 21 flap shaft [0059] 23 flap-side coupling part [0060] 25 drive-side coupling part [0061] 27 support section [0062] 28 support section [0063] 29 helical spring [0064] 31 first limb [0065] 32 second limb [0066] 33 wall section [0067] 35 recess [0068] 37 radial projection [0069] 39 holding projection [0070] 41 limb run-on slope [0071] 45 axial projection [0072] 47 radial projection run-on slope [0073] 49 contact surface [0074] 51 additional axial projection [0075] 55 recess [0076] 60 leadthrough