Arrangement of an air guide device on the underside of a motor vehicle

Abstract

Arrangement (1) of an air guide device (2) on an underside (3) of a motor vehicle (4), wherein the air guide device (2), by means of which, when the motor vehicle (4) is in motion, the air flowing towards the air guide device (2) can be directed in the direction of a rear (4a) of the motor vehicle (4), is arranged at least partially behind a rear wheel of the motor vehicle (4) in the longitudinal direction (7) of the motor vehicle (4), wherein the air guide device (2) has at least one first air guide area (15) around which air can flow, and the air guide device (2) has at least one second air guide area (16) around which air can flow and which extends outwards in the transverse direction (6) of the motor vehicle (4) to the first air guide area (15), which is arranged at least partially further down in the vertical direction (17) of the motor vehicle (4) than the first air guide area (15), wherein the rear wheel is arranged in a wheel housing (11),and wherein the second air guide area (16) extends directly to the rear of the wheel housing (11) in the longitudinal direction (7) of the vehicle, characterized in that the second air guide area (16) projects downwards beyond the wheel housing (11) in the vertical direction (17) of the vehicle.

Description

[0001] The invention relates to an arrangement of an air guide device on the underside of a motor vehicle according to the preamble of claim 1.

[0002] DE 10 2013 101 296 A1 discloses a motor vehicle with a rear-mounted air deflector arranged behind a rear wheel, from which a rear floor extends from a wheel cutout for the rear wheel in the bodywork, to which an upwardly oriented rear wall is attached. The rear floor, together with the rear wall, forms a one-sided rear contour of the bodywork.

[0003] Furthermore, DE 10 2018 112 474 A1 discloses a vehicle rear structure comprising a floor cover arranged behind a rear inner wheel arch in the vehicle front-to-rear direction, wherein the floor cover has an air inlet into which air flowing from a front to a rear in the vehicle front-to-rear direction is introduced, so that the air flows outwards in the vehicle width direction, and the floor cover has an air outlet arranged at a point outside the air inlet in the vehicle width direction, wherein the air outlet is an air outlet from which the air flowing outwards from the air inlet in the vehicle width direction is discharged outwards in the vehicle width direction and downwards in the vehicle height direction.

[0004] Furthermore, DE 297 03 392 U discloses a motor vehicle, in particular a passenger car, with an underbody running adjacent to the roadway, which is essentially smooth and has cutouts in the area of ​​the wheels, wherein the underbody, which is raised approximately from the rear axle, has laterally external, downwardly open, longitudinally directed air guide channels behind the rear wheels and that several elongated, adjacent guide channels are provided between the outer air guide channels on the rear diffuser-like underbody.

[0005] The object of the invention is to create an arrangement of an air guide device on the underside of a motor vehicle, so that the air resistance of the motor vehicle can be kept particularly low.

[0006] This problem is solved according to the invention by arranging an air guide device on the underside of a motor vehicle with the features of claim 1. Advantageous embodiments of the invention are the subject of the dependent claims and the description.

[0007] The invention relates to an arrangement of an air guide device on or at the underside, in particular in an underbody area and / or in a rear area, of a motor vehicle. The motor vehicle is, for example, a passenger car, commercial vehicle or truck.

[0008] The phrase "the air guide device is arranged on or at the underside of the motor vehicle" can be understood to mean, in particular, that the air guide device is arranged, especially at least indirectly or directly, on a component of the motor vehicle, wherein the component is arranged on or at the underside of the motor vehicle, i.e., that the component is located on or at the underside. The component is preferably designed separately from the air guide device. For example, the air guide device is arranged on an underbody and / or a rear underside of the motor vehicle, especially at least indirectly or directly.

[0009] The air guide device is arranged at least partially, and in particular predominantly or completely, behind a rear wheel of the vehicle in the longitudinal direction of the vehicle. In other words, the air guide device extends further rearward than the rear wheel in the longitudinal direction of the vehicle, and in particular at least partially, predominantly, or completely. Thus, the rear wheel is, for example, arranged in a first position, and the air guide device is arranged in a second position, which is different from the first position and is located rearward of the first position in the longitudinal direction of the vehicle.

[0010] Preferably, the motor vehicle, particularly in its fully manufactured state, has several wheels, with at least one of the wheels being the rear wheel and at least one other being the front wheel. The rear wheel is arranged behind the front wheel in the longitudinal direction of the vehicle. For example, the rear wheel is arranged on a rear axle of the vehicle, and the front wheel is arranged on a front axle, with the rear axle being located behind the front axle in the longitudinal direction of the vehicle and, in particular, being spaced apart from the front axle in the longitudinal direction of the vehicle.

[0011] The term "each vehicle wheel," particularly the rear and front wheels, can be understood as a ground contact element of the vehicle. This means that the vehicle, in its vertical direction, can be supported downwards by the rear wheel and / or the front wheel against a ground, for example, a roadway, and in particular directly. In other words, the respective vehicle wheel, especially the front wheel and / or the rear wheel, is designed as a ground contact element which, when the vehicle is driven along the ground while supported downwards by the respective vehicle wheel, rolls along the ground.

[0012] By means of the air guide device, the air flowing towards the vehicle, particularly directly, can be directed towards the rear of the vehicle, especially towards the rear of the vehicle, while the vehicle is in motion. In other words, it is designed so that, while the vehicle is in motion, the air flowing towards or around the air guide device can be directed by the air guide device towards the rear of the vehicle, especially towards the rear of the vehicle. Put another way, the air guide device is designed to direct the air flowing towards it while the vehicle is in motion.Thus, the air guide device, particularly during or while the vehicle is in motion, is exposed to or surrounded by the air flowing towards or around the vehicle. This means, in particular, that the air guide device is exposed to the air, especially directly, during the vehicle's motion, and is therefore exposed to or surrounded by air, particularly to direct the air towards the rear of the vehicle. Preferably, the air guide device is arranged in an airflow flowing around the vehicle, especially the underbody and / or the rear of the vehicle, during or while the vehicle is in motion.

[0013] The fact that the air guide device is designed or configured to direct the air flowing towards it can be understood, in particular, to mean that the air flowing towards the air guide device can be guided, for example, deflected or redirected, by means of the air guide device, especially by means of a geometry, particularly a shape, of the air guide device. Redirection can be understood, in particular, to mean that the direction of airflow towards the air guide device differs from the direction of airflow away from the air guide device.

[0014] The phrase "the air guide device is at least partially arranged behind the rear wheel" can be understood to mean, in particular, that the air guide device is arranged at least partially, and especially predominantly or completely, downstream of the rear wheel in the direction of airflow around the vehicle, particularly while the vehicle is in motion. The air guide device can, for example, be understood to be a displacement body that creates or enables a fluidic connection, particularly a direct one, between the rear wheel and a trailing element, especially the main trailing element, of the vehicle.For example, the air guide device is held in an effective position on or at the underside of the motor vehicle in such a way that the air guide device can direct outgoing air, which can in particular be described as flow air, in the trail of the rear wheel, in particular to direct the air to the rear of the vehicle or the main trail of the motor vehicle.

[0015] The air guidance device has at least one first air guidance area, which is open to airflow, particularly when the vehicle is in motion. The first air guidance area can be understood to be, in particular, a first air guidance element. For example, the first air guidance area has at least one first air guidance surface, which is open to airflow, particularly when the vehicle is in motion.

[0016] The term "airflow towards the air guide device" can refer in particular to air flowing around and / or along a surface of the air guide device. The term "air flowing towards the air guide device" can refer in particular to the airflow generated by the vehicle, especially while it is in motion.

[0017] In order to minimize the air resistance of the motor vehicle, particularly while driving, the invention provides that the air guide device has at least one second air guide area, which is open to airflow, particularly during driving, and which extends outwards in the transverse direction of the vehicle, particularly at least indirectly or directly, to the first air guide area. In other words, the first air guide area is located further inwards in the transverse direction of the vehicle than the second air guide area. The second air guide area is located at least partially, and in particular predominantly or completely, further down in the vertical direction of the vehicle than the first air guide area.In other words, the second air guide area extends downwards, at least partially, and in particular predominantly or completely, than the first air guide area in the vehicle's vertical direction. Again, the first air guide area is positioned at a first distance from the ground, particularly the roadway, and the second air guide area is positioned at a second distance from the ground, particularly the roadway, in the vehicle's vertical direction, the second distance being smaller than the first. The respective distances are preferably minimum distances. Thus, the second air guide area is positioned, in particular, below the first air guide area in the vehicle's vertical direction.This preferably results in a smaller, and in particular a smaller, flow cross-section in the area of ​​the second air guide area, especially in the upward direction of the vehicle, than in the area of ​​the first air guide area. This can be understood to mean, in particular, the following: For example, the first air guidance zone defines or forms a first flow cross-section in the vehicle's upward direction, through which the air flows, particularly when the vehicle is in motion. This first flow cross-section is bounded or can be bounded downwards in the vehicle's upward direction by the ground, particularly the road surface. Thus, the first flow cross-section extends, particularly in the vehicle's upward direction, for example, between the ground and the first air guidance zone. For example, the second air guidance zone defines a second flow cross-section in the vehicle's upward direction, which differs from the first and through which the air flows, particularly when the vehicle is in motion. This second flow cross-section is bounded or can be bounded downwards in the vehicle's upward direction by the ground, particularly the road surface.Thus, the second flow cross-section, particularly in the vehicle's vertical direction, extends between the ground and the second air guide area. Because the second air guide area is located at least partially lower than the first air guide area in the vehicle's vertical direction, the second flow cross-section, particularly at least partially, predominantly, or completely, preferably in the vehicle's vertical direction, is smaller than the first flow cross-section.

[0018] The second air guidance area can be understood to be, in particular, a second air guidance element that is different from the first air guidance element. For example, the second air guidance area has at least one second air guidance surface, which is in particular different from the first air guidance surface.

[0019] Preferably, it is provided that, during the journey of the motor vehicle, the air flowing towards the first air guidance area, in particular the first air guidance surface, can be directed by means of the first air guidance area, in particular by means of the first air guidance surface, towards the rear of the vehicle, preferably in a targeted manner. Preferably, it is provided that, during the journey of the motor vehicle, the air flowing towards the second air guidance area, in particular the second air guidance surface, can be directed by means of the second air guidance area, in particular by means of the second air guidance surface, towards the rear of the vehicle, preferably towards the rear of the vehicle.

[0020] The invention is based in particular on the following findings and considerations: For a particularly optimized aerodynamic flow, the rear wheel can be covered, especially over as large an area as possible, on its rear side, for example by means of at least one fairing element. It is particularly advantageous if the rear wheel is more covered on its rear side than on its front side, or if the fairing extends further downwards in the vertical direction of the vehicle on the rear side than on the front side. This allows, for example, the pressure loss of the air flowing around the rear wheel to be kept particularly low, which has a positive effect on air resistance.From a design perspective, a car's rear apron usually cannot be made so low; that is, particularly flat diffuser surfaces cannot be lowered sufficiently to have a particularly positive effect on air resistance.

[0021] Because, in the arrangement according to the invention, the second air guide area is positioned at least partially lower in the vertical direction of the vehicle than the first air guide area, the vehicle wheel is at least partially covered or can be covered by the second air guide area in the longitudinal direction of the vehicle towards the rear. This allows the degree of coverage of the vehicle wheel to be particularly increased on its rear side, and in particular greater than on its front side. This allows the pressure loss to be kept particularly low. The air flowing towards the second air guide area, and especially around the rear wheel, can be guided, particularly gently and smoothly, to the rear of the vehicle, and in particular into the trailing section of the vehicle.This can be achieved, for example, by a particularly smooth, continuous profile of the second air guide zone, especially in the longitudinal direction towards the rear of the vehicle. This allows detached airflow to reattach and / or reduces or minimizes turbulence, meaning that turbulence formation can be avoided or kept to a minimum. The first air guide zone allows an airflow, referred to as free flow, to pass through or around the underbody or rear section of the vehicle unimpeded. Free flow refers specifically to an airflow that bypasses the rear wheel or is not deflected by it.

[0022] Overall, it is evident that the air resistance of the motor vehicle can be kept particularly low by means of the arrangement according to the invention. In particular, the drag coefficient, especially in the longitudinal direction of the vehicle, can be kept particularly low or significantly improved. The drag coefficient can be expressed in particular as the drag coefficient or as the drag coefficient (c). w -value, especially c x The efficiency of the motor vehicle can be described as (value). This allows for an increase in the vehicle's efficiency. Therefore, the arrangement according to the invention is particularly advantageous for a motor vehicle that is specifically optimized for efficiency or is to be optimized, such as a battery electric vehicle (BEV).

[0023] The first air guide section is preferably designed as a diffuser, in particular as a rear diffuser. The second air guide section is, for example, not a diffuser. Thus, the first air guide section is, for example, a diffuser surface. In particular, the second air guide section is, for example, not a diffuser surface.

[0024] Furthermore, it is provided that the rear wheel is arranged, in particular at least partially or predominantly, within a wheel housing. The wheel housing can be understood to mean, in particular, a receiving space provided for the rear wheel, specifically for its arrangement. Thus, the rear wheel is, for example, accommodated within the wheel housing. The wheel housing is, for example, at least partially, and in particular completely, bounded or formed by at least one wheel housing shell. Thus, the vehicle wheel is, for example, covered by the wheel housing shell, particularly in the longitudinal direction of the vehicle.

[0025] Furthermore, it is provided that the second air guide area connects directly to the rear of the wheel arch in the longitudinal direction of the vehicle, for example, to the wheel arch liner. In other words, the air guide area is arranged directly adjacent to the wheel arch, and in particular the wheel arch liner, in the longitudinal direction of the vehicle. This allows the second air guide area to be subjected to particularly favorable airflow. In particular, the pressure loss can be kept especially low, thereby significantly improving the vehicle's aerodynamic drag. For example, the wheel arch, and in particular the wheel arch liner, and the second air guide area are connected to each other, at least indirectly or directly.

[0026] Furthermore, it is provided that the second air guide area, in particular an initial section of the second air guide area or the second air guide surface, extends downwards beyond the wheel housing, in particular the wheel housing liner, in the vertical direction of the vehicle. In other words, the second air guide area, in particular the second air guide surface, extends further downwards in the vertical direction of the vehicle than the wheel housing, in particular the wheel housing liner. This means that the second air guide area, in particular the initial section, is located at least partially, in particular predominantly or completely, further down in the vertical direction of the vehicle than the wheel housing, in particular the wheel housing liner. This allows, for example, the pressure loss of the air flowing through the wheel housing to be kept particularly low.In other words, the second air guide area can be subjected to the air flowing through the wheel arch shell in such a way that the air resistance can be kept particularly low.

[0027] In a further embodiment, it is provided that the first air guide zone is capable of being, or is, subjected to an airflow flowing around or along the underbody of the vehicle, bypassing or avoiding the wheel arch, and in particular directly. In other words, the first air guide zone is capable of being subjected to the airflow flowing around or along the underbody and bypassing the wheel arch. This airflow can be referred to as the first airflow. Specifically, the first airflow is a free flow, allowing it to flow over the first air guide zone to the vehicle, particularly unimpeded. This significantly improves the vehicle's aerodynamic drag. Thus, for example, a diffuser effect can be achieved by means of the first air guide zone.

[0028] In a further embodiment, it is provided that the second air guide area is directly subjected to an airflow, particularly when the vehicle is in motion, flowing through or around the wheel housing, which can be referred to as a second airflow. In other words, a second airflow approaching or flowing around the second air guide area, particularly the second air guide surface, first flows through the wheel housing. This means that the second airflow can be directed to the second air guide area via the wheel housing. As a result of the airflow approaching or flowing around the second air guide area, flow losses, particularly pressure losses, of the air flowing through the wheel housing can be kept particularly low. This significantly improves the vehicle's aerodynamic drag.

[0029] Preferably, the first airflow does not approach or flow around the second air guide area. Preferably, the first airflow does not approach or flow around the second air guide area. The airflows are preferably distinct from each other.

[0030] The second air guide area, in particular the second air surface, and the wheel arch liner are preferably designed separately from each other. Alternatively, the second air guide area and the wheel arch liner are, for example, formed together as a single piece, i.e., joined together in one piece.

[0031] The initial area can be understood, in particular, as the beginning or initial region of the second air guidance area, relative to the longitudinal direction of the vehicle. Thus, the initial area is, for example, an initial surface or an initial edge, where the initial surface or the initial edge is, for example, designed as the beginning of the second air guidance area in the longitudinal direction of the vehicle.

[0032] In a further embodiment, the second air guide section extends longitudinally to the rear of the vehicle, at least substantially to one end of the vehicle's rear. In other words, the end of the second air guide section extends longitudinally to the rear of the vehicle, at least substantially to the end of the vehicle's rear. Again, in other words, the air guide device, and in particular the second air guide section, directs the airflow directly to the rear of the vehicle, and especially into the main trailing section. This allows the vehicle's air resistance to be kept particularly low. The end of the vehicle's rear can be understood to mean, in particular, the end of the vehicle's rear in the longitudinal direction.

[0033] In a further embodiment, the first air guide area extends rearward in the longitudinal direction of the vehicle to a first end section, and the second air guide area extends rearward in the longitudinal direction of the vehicle to a second end section. The second end section is positioned at approximately the same height as the first end section in the vertical direction of the vehicle. In other words, the air guide areas connect at the same height, or at the same level, relative to the vehicle's vertical direction, particularly in the transverse direction. This allows the air to be guided particularly smoothly, and especially while avoiding excessive turbulence, into the main wake of the vehicle.This allows air resistance to be kept particularly low.

[0034] Thus, the respective air guidance area extends in the longitudinal direction of the vehicle, for example, from its respective starting point to its respective end point. The respective end point can therefore be understood as the respective end of the respective air guidance area in relation to the longitudinal direction of the vehicle. In particular, the respective air guidance area does not extend beyond its respective end point; that is, the respective end point of the respective air guidance area in the longitudinal direction of the vehicle is the respective end of the respective air guidance area, with the respective end point being the rearward boundary of the respective air guidance area in the longitudinal direction of the vehicle.

[0035] In a further embodiment, the second air guide area extends obliquely to a horizontal plane of the vehicle, perpendicular to its vertical direction. In other words, the second air guide area is angled, particularly vertically, towards the ground, especially the road surface. This means that the second air guide area extends obliquely to the ground at an angle. This allows the air flowing into the second air guide area to be directed precisely, and particularly gently, towards the rear of the vehicle, and especially the main trailing edge. The angle, which can be referred to as the first angle, is, for example, less than 45 degrees, and in particular less than 40, 35, 30, or 25 degrees. The angle can, for example, be understood to be the maximum angle of the second air guide area.

[0036] The fact that the horizontal plane extends perpendicular to the vehicle's vertical direction can be understood in particular to mean that a normal vector of the horizontal plane runs parallel to the vehicle's vertical direction.

[0037] In a further embodiment, the second air guide area extends obliquely to a longitudinal plane of the vehicle, which is perpendicular to the transverse direction of the vehicle. In other words, the second air guide area, and in particular the second air guide surface, extends obliquely to the longitudinal plane of the vehicle at an angle, which can be referred to as the second angle. This allows the air flowing towards or acting upon the second air guide area to be directed to the rear of the vehicle, and in particular the main trailing section, particularly advantageously, and especially gently, with particularly low flow losses. Preferably, the longitudinal plane of the vehicle is a longitudinal center plane, which can be referred to as the longitudinal center plane. Thus, the second air guide area extends, for example, obliquely at the second angle to a longitudinal center axis of the vehicle.

[0038] The fact that the longitudinal plane of the vehicle runs perpendicular to the transverse direction of the vehicle can be understood in particular to mean that a normal vector of the longitudinal plane of the vehicle runs parallel to the transverse direction of the vehicle.

[0039] Further features of the invention will become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations or on their own.

[0040] The invention will now be explained in more detail with reference to a preferred embodiment and the drawings. The drawings show: Fig. 1 a schematic underside view of an arrangement of an air guide device according to the invention on the underside of a motor vehicle; and Fig. 2 a schematic perspective view of an arrangement of an air guide device according to the invention on the underside of a motor vehicle; and Fig. 3 a schematic rear view of an arrangement of an air guide device according to the invention on the underside of a motor vehicle; and Fig. 4 a schematic and perspective front view of an arrangement of an air guide device according to the invention on the underside of a motor vehicle.

[0041] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0042] Fig. Figure 1 shows a schematic bottom view of an arrangement 1 of an air guide device 2 on the underside 3 of a motor vehicle 4. In the exemplary embodiment, two air guide devices 2, 5 are provided, in particular those designed separately from one another. Preferably, the motor vehicle 4, especially in its fully manufactured state, has the air guide devices 2, 5. The motor vehicle 4 is, for example, designed as a battery-electric vehicle or as a hybrid vehicle.

[0043] As in Fig. As shown in Figure 1, the air guide devices 2 and 5 are spaced apart from each other in the transverse direction 6 of the motor vehicle 4. A first air guide device 2 can in particular be referred to as the first air guide device 2. The second air guide device 5 can in particular be referred to as the second air guide device 5.

[0044] Fig. Figure 2 shows the arrangement 1 in a schematic perspective view. Fig. Figure 3 shows arrangement 1 in a schematic rear view. Thus, arrangement 1 is in Fig. 3 in the longitudinal direction of the vehicle 7 of the motor vehicle 4 shown from the rear. Fig. Figure 4 shows arrangement 1 in a schematic and perspective front view. Thus, arrangement 1 is in Fig. 4 in the longitudinal direction of the vehicle, 7 shown in perspective from the front. In particular, in Fig. 1, Fig. 2, Fig. 3 to Fig. 4 shows a respective schematic partial view of the motor vehicle 4.

[0045] The respective air guide device 2, 5, by means of which, during travel of the motor vehicle 4, the air flowing towards the respective air guide device 2, 5 can be directed towards a rear of the vehicle 4a, in particular towards the rear of the vehicle 4, is arranged at least partially, in particular predominantly or completely, behind a respective rear wheel of the motor vehicle 4 in the longitudinal direction 7 of the vehicle 4. For example, the first air guide device 2 is assigned to a first rear wheel of the motor vehicle 4 and the second air guide device 5 is assigned to a second rear wheel of the motor vehicle 4, which is spaced apart from the first rear wheel, in particular in the transverse direction 6 of the vehicle. Thus, the first air guide device 2 is arranged, for example, at least partially, in particular predominantly or completely, behind the first rear wheel in the longitudinal direction 7 of the vehicle.For example, the second air guide device 5 is arranged at least partially, in particular predominantly or completely, behind the second rear wheel in the longitudinal direction of the vehicle 7.

[0046] Preferably, a longitudinal plane 8 of the vehicle 4, in particular a longitudinal median plane, extends perpendicular to the transverse direction 6 of the vehicle. For example, the first rear wheel, and in particular the first air guide 2, is arranged on a first side 9 of the longitudinal plane 8. For example, the second rear wheel, and in particular the second air guide 5, is arranged on a second side 10 of the longitudinal plane 8, which is distinct from the first side 9. Preferably, the second side 10 is opposite side 9. Thus, the first rear wheel is, for example, configured as the left rear wheel and the second rear wheel is, for example, configured as the right rear wheel.

[0047] Preferably, each rear wheel is arranged in a respective wheel housing 11, 12. This means that the first rear wheel, in particular at least partially, predominantly, or completely, is arranged in a first wheel housing 11, and the second rear wheel, in particular at least partially, predominantly, or completely, is arranged in a second wheel housing 12, which is distinct from the first wheel housing 11, and in particular spaced apart from it in the transverse direction 6 of the vehicle. Preferably, the first wheel housing 11 is arranged on the first side 9, and the second wheel housing 12 is arranged on the second side 10. Preferably, each wheel housing 11, 12 is at least partially, in particular predominantly or completely, bounded by a respective wheel housing shell 13, 14. This means that the first wheel housing 11 is bounded or formed by a first wheel housing shell 13.The second wheel housing 12 is bounded or formed by a second wheel housing shell 14, which is specifically designed separately from the first wheel housing shell 13. In the figure shown in . Fig. 1, Fig. 2, Fig. 3 to Fig. In the embodiment shown in Figure 4, the respective air guide device 2, 5 is arranged at least partially, in particular predominantly or completely, behind the respective wheel housing 11, 12, in particular the respective wheel housing shell 13, 14, in the longitudinal direction of the vehicle 7.

[0048] Each air guidance device 2, 5 has at least one first air guidance area 15, which is exposed to airflow, particularly when the motor vehicle 4 is in motion. The first air guidance area 15 can be understood to be, in particular, a first air guidance element of the respective air guidance device 2, 5. The respective first air guidance area 15 is, for example, designed as a diffuser, in particular as a rear diffuser, of the motor vehicle 4.

[0049] In order to keep the air resistance of the motor vehicle 4 particularly low, it is provided that the respective air guide device 2, 5 has at least one respective second air guide area 16 which is surrounded or approached by air and which extends outwards in the transverse direction 6 of the motor vehicle 4, in particular at least indirectly or directly, adjoins the respective first air guide area 15, and which is arranged in the vertical direction 17 of the motor vehicle 4 at least partially, in particular predominantly or completely, further down than the respective first air guide area 15.

[0050] Preferably, it is provided that the respective first air guide area 15 can be supplied with an airflow 19, 20 flowing around the underbody 18 of the motor vehicle 4, bypassing the respective wheel well 11, 12. This means that the first air guide area 15 of the first air guide device 2 can be supplied with an airflow 19 flowing around the underbody 18, bypassing the first wheel well 11, in particular the second wheel well 12. The first air guide area 15 of the second air guide device 5 can be supplied with an airflow 20 flowing around the underbody 18, bypassing the second wheel well 12, in particular the first wheel well 11. This is in Fig. Figure 1 illustrates this. Thus, the respective airflow 19, 20 can be guided or directed over the respective first air guidance area 15, bypassing the respective wheel housing 11, 12, towards the rear of the vehicle 4a, and in particular to the rear of the vehicle 4a.

[0051] Preferably, each second air guide section 16 can be supplied with a respective airflow 21, 22 flowing through the respective wheel housing 11, 12. This means that the second air guide section 16 of the first air guide device 2 can be supplied with a third airflow 21 flowing through the first wheel housing. The second air guide section 16 of the second air guide device 5 can be supplied with a fourth airflow 22 flowing through the second wheel housing 12. The airflows 19, 20, 21, 22 are preferably each distinct from the others.

[0052] In a further embodiment, it is provided that the respective second air guide area 16 connects to the rear in the longitudinal direction 7 of the vehicle, in particular at least indirectly or directly, to the respective wheel housing 11, 12. This means that the second air guide area 16 of the first air guide device 2 connects to the rear in the longitudinal direction 7 of the vehicle, in particular at least indirectly or directly, to the first wheel housing 11. The second air guide area 16 of the second air guide device 5 connects to the rear in the vertical direction 17 of the vehicle, in particular at least indirectly or directly, to the second wheel housing 12.

[0053] For example, in Fig. As shown in Figure 2, in the embodiment it is provided that the respective second air guide area 16, in particular a respective initial area of ​​the respective second air guide area 16, projects downwards over the respective wheel housing 11, 12, in particular the respective wheel housing shell 13, 14, in the vehicle vertical direction 17.

[0054] For example, each air guide device 2, 5 has at least one end face 23 which adjoins, in particular at least indirectly or directly, the respective second air guide area 16. Preferably, the respective end face 23 extends obliquely or perpendicularly to the respective first air guide area 15 and / or the respective second air guide area 16. For example, the respective end face 23 adjoins, in particular at least indirectly or directly, the respective wheel arch 11, 12, in particular the respective wheel arch shell 13, 14, downwards in the vehicle's vertical direction 17. Thus, the respective end face 23 is arranged, for example, in the vehicle's vertical direction 17, at least partially, in particular predominantly or completely, further down than the respective wheel arch shell 13, 14.

[0055] Overall, it is evident that the respective airflow 21, 22 can be guided via the respective wheel arch 11, 12, and in particular via the respective frontal area 23, to the respective second air guide area 16. In particular, the respective frontal area 23 serves as additional cladding or covering for the respective rear wheel, especially compared to the respective wheel arch shell 13, 14. Thus, the respective rear wheel is particularly well covered on its rear side, which, for example, minimizes pressure loss in the respective airflow 21, 22. Via the respective second air guide area 16, the respective airflow 21, 22 can be directed, in particular with minimal flow loss, to the rear of the vehicle 4a, and in particular into a wake of the rear of the vehicle 4a. This allows the aerodynamic drag of the vehicle 4 to be kept particularly low.Furthermore, the respective airflow 19, 20 can flow along the underbody 18 via the respective first air guide area 15 with particularly low loss or without obstruction and be directed to the rear of the vehicle 4a, in particular into the wake of the rear of the vehicle 4a. This allows the air resistance of the motor vehicle 4 to be kept particularly low.

[0056] Preferably, the respective second air guide area 16 extends rearward in the longitudinal direction 7 of the vehicle at least substantially to an end region 24 of the rear of the vehicle 4a. Thus, the respective second air guide area 16 extends rearward in the longitudinal direction 7 of the vehicle, for example, to a rear end of the motor vehicle 4. The contour or shape of the respective second air guide area 16 is preferably designed to be particularly smooth, meaning that any changes in shape of the respective second air guide area in the vertical direction 17 along the longitudinal direction 7 of the vehicle are preferably kept particularly small. This allows the airflow to re-establish itself and / or prevents the airflow from separating.

[0057] For example, in Fig. As shown in Figure 3, a further embodiment provides that the respective first air guidance area 15 extends in the longitudinal direction 7 of the vehicle rearward to a respective first end area 25 of the respective first air guidance area 15, and that the respective second air guidance area 16 extends in the longitudinal direction 7 of the vehicle rearward to a respective second end area 26 of the respective second air guidance area 16, which is arranged in the vertical direction 17 of the vehicle at least substantially at the same height as the respective first end area 25.

[0058] Preferably, the respective second air guide area 16 extends obliquely to the vehicle longitudinal plane 8, which runs perpendicular to the vehicle's transverse direction 6. Preferably, the respective second air guide area 16 extends obliquely to a horizontal plane 27, which runs perpendicular to the vehicle's vertical direction 17. The horizontal plane 27 is in Fig. 1 is illustrated particularly schematically.

[0059] For example, it is provided that a respective distance 28 extending in the vehicle's upward direction 17 between the respective second air guide area 16 and a roadway 34 increases towards the rear along the vehicle's longitudinal direction 7. This allows the air flowing through the respective second air guide area 16 to be directed upwards, and in particular redirected, as it flows towards the rear of the vehicle 4a through the respective second air guide area 16 in the vehicle's upward direction 17.

[0060] The respective second air guide area 16 defines a flow cross-section through which the air, particularly during the movement of the vehicle 4, can flow upwards in the vehicle's vertical direction 17. This flow cross-section is bounded or can be bounded downwards in the vehicle's vertical direction 17 by the roadway 34. The air flowing towards or around the respective second air guide area can be directed through this flow cross-section in the direction of the vehicle's rear 4a, specifically towards the rear of the vehicle 4a or its wake. For example, it is provided that the respective flow cross-section increases along the vehicle's longitudinal direction 7 in the vehicle's vertical direction 17.

[0061] In the exemplary embodiment, the respective air guide sections 15, 16 of the respective air guide device 2, 5 are connected to each other via a respective connection section 29, preferably directly. The respective connection section 29 preferably extends obliquely or perpendicularly to the respective air guide section 15, 16 of the respective air guide device 2, 5. The respective connection section 29 can be understood to be, in particular, a respective transition section. For example, the respective air guide sections 15, 16 are integrally connected to each other via the respective connection section 29. Alternatively, the respective air guide sections 15, 16 of the respective air guide device 2, 5 are formed separately from each other and connected to each other.

[0062] In the Fig.In the embodiment shown in Figure 1, a floor element 30 is arranged, particularly in the transverse direction 6 of the vehicle, between the air guides 2, 5, which is designed, for example, as the rear floor of the vehicle 4. The air guides 2, 5 are preferably connected to the floor element 30, particularly directly. For example, the floor element 30 is arranged in the vertical direction 17 of the vehicle under a rear apron 31 of the vehicle 4. For example, the vehicle 4 has a second floor element 32, which is designed separately from the floor element 30 and is preferably, particularly directly, connected to the floor element 30. The second floor element 32 is arranged in the longitudinal direction 7 of the vehicle in front of the first floor element 30. The second floor element 32 extends in the transverse direction 6 of the vehicle between the wheel arches 11, 12. The second floor element 32 is preferably part of the underbody 18.Thus, the underbody 18 is at least partially formed by the second floor element 32. The respective air guide device 2, 5 is therefore arranged, for example, at least indirectly, and in particular directly, on the first floor element 30. The respective wheel arch shell 13, 14 and / or the first floor element 30 and / or the second floor element 32 is, for example, part of a, in particular self-supporting, body of the motor vehicle 4.

[0063] For example, each air guide device 2, 5 has a third air guide area 33, which extends outwards in the transverse direction 6 of the vehicle, in particular at least indirectly or directly, to the respective second air guide area 16. The respective third air guide area 33 extends, for example, obliquely or perpendicularly to the respective second air guide area.

[0064] Numerals, such as "first," "second," "third," etc., are intended solely for differentiation and do not, in particular, indicate an order. This means that the corresponding numerals can be interchanged arbitrarily. Reference symbol list 1. Arrangement 2 first air guide device 3 Underside 4 motor vehicles 4a Vehicle rear 5 second air guide device 6 Vehicle transverse direction 7 Vehicle longitudinal direction 8 Vehicle longitudinal plane 9 first page 10 second page 11 first wheel housing 12 second wheel housing 13 first wheel arch shell 14 second wheel arch shell 15 first air guidance area 16 second air guidance area 17 Vehicle uphill 18 Underbody 19 first airflow 20 second airflow 21 third airflow 22 fourth airflow 23 Front surface 24 End area of ​​the vehicle rear 25 first end range 26 second end range 27 Horizontal plane 28 distance 29 Connection area 30 first floor element 31 Rear apron 32 second floor element 33 third air guidance area 34 lanes

Claims

Arrangement (1) of an air guide device (2) on an underside (3) of a motor vehicle (4), wherein the air guide device (2), by means of which, when the motor vehicle (4) is in motion, the air flowing towards the air guide device (2) can be directed in the direction of a rear (4a) of the motor vehicle (4), is arranged at least partially behind a rear wheel of the motor vehicle (4) in the longitudinal direction (7) of the motor vehicle (4), wherein the air guide device (2) has at least one first air guide area (15) around which air can flow, and the air guide device (2) has at least one second air guide area (16) around which air can flow and which extends outwards in the transverse direction (6) of the motor vehicle (4) to the first air guide area (15), which is arranged at least partially further down in the vertical direction (17) of the motor vehicle (4) than the first air guide area (15), wherein the rear wheel is arranged in a wheel housing (11),and wherein the second air guide area (16) extends directly to the rear of the wheel housing (11) in the longitudinal direction (7) of the vehicle, characterized in that the second air guide area (16) projects downwards beyond the wheel housing (11) in the vertical direction (17) of the vehicle. Arrangement (1) according to claim 1 , characterized in that the first air guide area (15) can be acted upon by an airflow (19) flowing around an underbody (18) of the motor vehicle (4) bypassing the wheel housing (11). Arrangement (1) according to claim 1 or 2, characterized in that the second air guide area (16) can be acted upon by an airflow (21) flowing through the wheel housing (11). Arrangement (1) according to one of the preceding claims, characterized in that the second air guide area (16) extends in the longitudinal direction (7) of the vehicle to the rear at least substantially to an end area (24) of the rear of the vehicle (4a). Arrangement (1) according to one of the preceding claims, characterized in that the first air guidance area (15) extends in the longitudinal direction of the vehicle (7) to the rear to a first end area (25) of the first air guidance area (15) and the second air guidance area (16) extends in the longitudinal direction of the vehicle (7) to the rear to a second end area (26) of the second air guidance area (16), which is arranged in the vertical direction of the vehicle (17) at least substantially at the same height as the first end area (25). Arrangement (1) according to one of the preceding claims, characterized in that the second air guide area (16) extends obliquely to a horizontal plane (27) of the motor vehicle (4) perpendicular to the vehicle vertical direction (17). Arrangement (1) according to one of the preceding claims, characterized in that the second air guide area (16) extends obliquely to a vehicle longitudinal plane (8) extending perpendicular to the vehicle transverse direction (6).

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