Motor vehicle with a rear diffuser and with a trailer hitch and method for operating such a motor vehicle

Abstract

Motor vehicle (1) with a rear diffuser (3) comprising a diffuser element (4) which is movable into a diffuser position (7) in order to influence the driving behavior of the motor vehicle (1) with regard to downforce and air resistance with an aerodynamically effective diffuser area (5), and with a trailer hitch (70), wherein the diffuser element (4) has a recess (23;74) for the trailer hitch (70) in its aerodynamically effective diffuser area (5), characterized in that the recess (23;74) in the aerodynamically effective diffuser area (5) of the diffuser element (4) has the shape of an isosceles trapezoid (77;79) which widens towards the rear.

Description

[0001] The invention relates to a motor vehicle with a rear diffuser according to the preamble of claim 1.

[0002] German patent application DE 10 2021 111 761 A1 discloses a motor vehicle with a rear diffuser adjustable about a pivot axis and a retractable trailer hitch, wherein the trailer hitch can only be extended when the rear diffuser is in the extended position. German patent application DE 10 2012 014 176 A1 discloses a bumper cover with a cover element, wherein a trailer hitch can be extended when the cover element is open. European patent application EP 3 357 800 B1 discloses a rear apron of a motor vehicle which has an air guide element adjustable in the longitudinal direction of the vehicle. German patent application DE 10 2015 016 717 A1 discloses a motor vehicle with a rear fairing adjustable in the longitudinal direction of the vehicle.German patent DE 10 2019 110 770 B4 discloses a rear diffuser for a motor vehicle which is first adjusted rotationally and then translationally during an extension process. German patent application DE 10 2020 132 244 A1 discloses a motor vehicle with a rear diffuser comprising a diffuser element that can be moved into a diffuser position to influence the vehicle's handling characteristics with regard to downforce and air resistance. In a closed position, the diffuser element covers an opening of a trailer hitch, which is uncovered by the diffuser element in an open position. The diffuser element is designed as a box diffuser element and has a recess in the area of ​​the extended trailer hitch, allowing the diffuser element to perform its normal diffuser function even when the trailer hitch is extended.Other motor vehicles of this type with a rear diffuser and a trailer hitch are known from German publication DE 10 2021 111 756 A1 and German patent DE 10 2021 111 754 B3.

[0003] The object of the invention is to functionally improve a motor vehicle according to the preamble of claim 1.

[0004] The problem is solved by a motor vehicle with the features of claim 1. The diffuser element is, for example, a diffuser blade. The diffuser element can be designed and arranged in its diffuser position such that the entire diffuser element or a complete side, for example, an underside, exerts an aerodynamic effect when the motor vehicle is driven at a preferably relatively high speed. Depending on the design of the diffuser element, however, only a section, for example, a rear end section of the diffuser element, exerts an aerodynamic effect in its diffuser position. When the diffuser element is in its retracted position, it exerts no or no significant aerodynamic effect. The diffuser element can be pivotably and / or translationally movable and mounted in or on a rear section of the motor vehicle.The claimed recess in the aerodynamically effective diffuser area of ​​the diffuser element allows a trailer hitch to be extended or attached to the vehicle, particularly when the diffuser element is in its retracted position, which can also be described as the passive position. This offers the advantage, among others, that the trailer hitch can always be mounted or extended when the vehicle is stationary, because the diffuser element is normally inactive in this position. The recess advantageously has rounded corners rather than sharp edges. Depending on the design, the isosceles trapezoid can also be combined with a rectangle within the recess. Furthermore, the recess can extend in only one plane. If required, especially for a plug-in trailer hitch, for example, the recess can also be three-dimensional.The trapezoidal extension of the recess to the rear has proven advantageous both with regard to the mounting of a trailer coupling, for example a plug-in coupling, and to aerodynamics.

[0005] A preferred embodiment of the motor vehicle is characterized in that the recess for the trailer hitch in the aerodynamically effective diffuser area is completely or partially concealed on the vehicle side when the diffuser element is in a retracted position. This offers the advantage that the recess is not visible on the motor vehicle when the diffuser element is retracted.

[0006] Another preferred embodiment of the motor vehicle is characterized in that the diffuser element is translationally movable between its retracted position and its diffuser position. It is accepted that the diffuser element cannot be mounted or extended when a trailer hitch is installed. This is accepted, among other reasons, because the diffuser element is not needed, or is less likely to be needed, when the trailer hitch is mounted or extended due to the reduced speed during trailer operation.

[0007] Another preferred embodiment of the motor vehicle is characterized in that the recess in the aerodynamically effective diffuser area of ​​the diffuser element is adapted in its shape to a manually mountable trailer hitch. This makes it possible to mount the trailer hitch to the motor vehicle in a simple manner, particularly when the diffuser element is retracted.

[0008] Another preferred embodiment of the motor vehicle is characterized in that the recess in the aerodynamically effective diffuser area of ​​the diffuser element is adapted in its shape to an envelope along which a trailer hitch is retractable and extendable, in particular pivotable and extendable, on the motor vehicle. This ensures the extension and retraction, in particular pivoting and swiveling, of the trailer hitch in a simple manner, at least when the diffuser element is retracted.

[0009] Another preferred embodiment of the motor vehicle is characterized in that the recess in the aerodynamically effective diffuser area of ​​the diffuser element is designed and arranged symmetrically. This offers the advantage that the appearance is not impaired by the recess in the diffuser element when the diffuser element is extended. However, this comes at the cost of certain aerodynamic disadvantages when the diffuser element is extended. The symmetrical design and arrangement of the recess is particularly problematic when the envelope of the trailer hitch on the motor vehicle is asymmetrical. The claimed recess is preferably arranged centrally in the transverse direction of the vehicle and symmetrically within the aerodynamically effective diffuser area.

[0010] Another preferred embodiment of the motor vehicle is characterized in that the recess in the aerodynamically effective diffuser area of ​​the diffuser element has a straight baseline extending in a transverse direction of the vehicle. This has proven advantageous with regard to aerodynamics and also with regard to the desired function of the recess in relation to the trailer hitch.

[0011] In a method for operating a previously described motor vehicle, the problem stated above is solved alternatively or additionally by moving the diffuser element into its diffuser position only when the trailer hitch is not mounted or activated. In this case, the diffuser element remains retracted. This is relatively unproblematic, among other reasons, because the diffuser element is generally not needed when the trailer hitch is mounted or activated, since the permissible maximum speed of the motor vehicle is limited when towing a trailer or when accessories are mounted on the trailer hitch.

[0012] Further advantages, features, and details of the invention will become apparent from the following description, in which various exemplary embodiments are described in detail with reference to the drawing. The drawing shows: Fig. 1 a perspective view of the rear of a motor vehicle with a rear diffuser designed as a sliding diffuser in its retracted state; Fig. 2 the same representation as in Fig. 1 with extended rear diffuser; Fig. 3 the retracted rear diffuser in a side view; Fig. 4 the extended rear diffuser in side view; Fig. 5 a perspective view of a diffuser blade of the rear diffuser from the Fig. 1, Fig. 2, Fig. 3 to Fig. 4 with a central drive unit arranged between two actuator units in an exploded view; Fig. 6 a perspective view of the rear diffuser with the central drive unit and the two actuator units with the diffuser element in its retracted position; Fig. 7 the same representation as in Fig. 6 with the diffuser element in its extended position; and the Fig. 8, Fig. 9 to Fig. 10 different views of a trailer hitch on the motor vehicle from the Fig. 1, Fig. 2, Fig. 3 to Fig. 4 in two versions of a trailer hitch.

[0013] In the Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 shows the rear section 2 of a motor vehicle 1 with a rear diffuser 3 in various views and operating states. Fig. 1 and Fig. 3 A diffuser element 4 of the rear diffuser 3 is located in its retracted position, which is also referred to as the passive position 6. In the Fig. 2 and Fig. 4 the diffuser element 4 is in its extended position, which is also referred to as active position or diffuser position 7.

[0014] The diffuser element is designed, for example, as a diffuser blade with an aerodynamically effective diffuser area 5 at its rear end. Within the aerodynamically effective diffuser area 5, the diffuser element 4 has a recess 23. The recess 23 allows for the extension or mounting of a [missing element name] in the [missing element name]. Fig. 1, Fig. 2, Fig. 3 to Fig. 4 trailer coupling not shown, but only if the diffuser element 4 is in its retracted position or passive position 6.

[0015] Diffuser element 4 is in the Fig. 1, Fig. 2, Fig. 3 to Fig. The diffuser element 4 is guided at the bottom of a support structure 8 of the motor vehicle 1 and is translationally movable back and forth between its retracted position 6 and its extended position 7. The extension and retraction of the diffuser element 4 is advantageously carried out automatically by a suitable electric motor drive.

[0016] In the Fig. 5, Fig. 6 to Fig. Figure 7 illustrates how the diffuser blade or diffuser element 4 of the rear diffuser 3 is guided and driven translationally on the support structure 8 of the motor vehicle. The support structure 8 comprises a support element 9 on which an actuator 10 is mounted.

[0017] The actuator 10 comprises a left actuator unit 11 and a right actuator unit 12. The terms left and right refer to a rearward view of the rear of the vehicle. The two actuator units 11 and 12 are mounted at opposite ends of the support element 9.

[0018] Essentially midway between the two actuator units 11 and 12, a central drive unit 13 is attached to the support element 9. The central drive unit 13 comprises a drive shaft 14, which is driven, for example, by an electric motor within the central drive unit 13.

[0019] A left shaft section 15 of the drive shaft 13 is connected to the left actuator unit 11. A right shaft section 16 of the drive shaft 14 is connected to the right actuator unit 12. Thus, both actuator units 11 and 12 can be driven by only one drive shaft 14 of the central drive unit 13.

[0020] A dashed arrow 19 indicates in Fig. Figure 5 indicates that the actuator units 11 and 12 are attached to defined mounting points 17 and 18 of the diffuser element 4. The attached state is shown in the Fig. 6 and Fig. 7 shown.

[0021] In Fig. 6 the diffuser element 4 of the rear diffuser 3 is in its retracted position 6. In Fig. 7 the diffuser element 4 of the rear diffuser 3 is in its extended position 7. A double arrow 20 indicates in Fig. Seven translational movements of the diffuser element 4 between its two positions 6 and 7 are indicated. The left actuator unit 11 includes a guide device 30. An identical but mirror-image guide device is assigned to the right actuator unit 12.

[0022] The guide device 30 comprises an elongated guide element 31 designed as a guide rod 34. A guide body 32, designed as a guide cylinder 33, is guided on the guide rod 34 so as to be movable back and forth translationally. The diffuser element 4 thus guided is driven by the central drive unit 13.

[0023] In the Fig. 8, Fig. 9 to Fig. 10 is a trailer coupling device 70 on the rear part 2 of the motor vehicle 1 from the Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 illustrates the trailer hitch 70 in the Fig. 8 and Fig. 10 includes a mountable trailer coupling designed as a plug-in coupling 71. In Fig. 8 indicates that the diffuser element 4 of the rear diffuser 3 may have differently designed recesses depending on the design of the trailer coupling device 70 '23; 74.

[0024] In Fig. Figure 9 illustrates the movements of the trailer coupling 72 during retraction and extension, particularly during pivoting and swiveling, at the rear section 2 of the motor vehicle 1 by means of an envelope curve 73. The diffuser element 4 is located in Fig. 9 in its established position, which is also referred to as passive position 6.

[0025] The recess 23 includes a baseline 76 that runs transversely to the vehicle. Furthermore, the recess 74 has the shape of a trapezoid 77 that widens towards the rear. The recess 23 is symmetrical and therefore larger than the envelope 73 would require.

[0026] In Fig. Figure 8 shows that the recess 74 for the mountable trailer hitch 71 also has a baseline 75. Furthermore, the recess 74, in plan view, has a rectangle 78 combined with a trapezoid 79 that widens towards the rear.

[0027] In Fig. Figure 10 shows that the recess 74 for the mountable trailer hitch 71 is also three-dimensional. The diffuser element 4 is also located in Fig. 10 in his established position. Reference sign 1 motor vehicle 2 Rear section 3 Rear diffuser 4 Diffuser element 5 aerodynamically effective diffuser area 6 retracted position 7 extended position 8 Supporting structure 9 Supporting element 10 Actuators 11 left actuator unit 12 right actuator unit 13 central drive unit 14 Drive shaft 15 left wave section 16 right wave section 17 cultivation site 18 cultivation site 19 dashed arrow 20 Double Arrow 23 recess 70 Towing device 71 Towbar 72 Towbar 73 Envelope 74 recess 75 baseline 76 baseline 77 Trapez 78 Rectangle 79 Trapez

Claims

[1] Motor vehicle (1) with a rear diffuser (3) comprising a diffuser element (4) which is movable into a diffuser position (7) in order to influence the driving behavior of the motor vehicle (1) with regard to downforce and drag by means of an aerodynamically effective diffuser area (5), and with a trailer hitch (70), wherein the diffuser element (4) has a recess (23;74) for the trailer hitch (70) in its aerodynamically effective diffuser area (5), characterized by , that the recess (23;74) in the aerodynamically effective diffuser area (5) of the diffuser element (4) has the shape of an isosceles trapezoid (77;79) which widens towards the rear. [2] Motor vehicle (1) according to claim 1, characterized by, that the recess (23;74) for the trailer coupling device (70) in the aerodynamically effective diffuser area (5) is completely or partially obscured on the vehicle side when the diffuser element (4) is in a retracted position (6). [3] Motor vehicle (1) according to any one of the preceding claims, characterized by , that the diffuser element (4) is translationally movable between its retracted position (6) and its diffuser position (7). [4] Motor vehicle (1) according to claims 1 to 3, characterized by , that the recess (23,74) in the aerodynamically effective diffuser area (5) of the diffuser element (4) is adapted in its shape to a manually mountable trailer hitch (71). [5] Motor vehicle (1) according to claims 1 to 3, characterized by, that the recess (23;74) in the aerodynamically effective diffuser area (5) of the diffuser element (4) is adapted in its shape to an envelope along which a trailer coupling (72) is attached to the motor vehicle (1) in a way that can be extended and retracted, in particular in a way that can be swivelled out and in. [6] Motor vehicle (1) according to any one of the preceding claims, characterized by , that the recess (23;74) in the aerodynamically effective diffuser area (5) of the diffuser element (4) is designed and arranged symmetrically. [7] Motor vehicle (1) according to any one of the preceding claims, characterized by , that the recess (23;74) in the aerodynamically effective diffuser area (5) of the diffuser element (4) has a straight baseline (75;76) extending in a transverse direction of the vehicle. [8] Method for operating a motor vehicle (1) according to any one of the preceding claims, characterized by, that the diffuser element (4) is only moved into its diffuser position (7) when the trailer hitch (70) is not mounted or not activated.

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