Motor vehicle with a motor vehicle body and an underbody

Abstract

The invention relates to a motor vehicle (1) with a motor vehicle body (2) and with an underbody (3), wherein the motor vehicle body (2) has a left-side wheel housing (6) and a right-side wheel housing (6) in a front area (4) and a rear area (5), and wherein at least one of the wheel housings (6) has an air guide element (8) formed in the direction of travel (F) in front of a wheel (7) received in the wheel housing (6). According to the invention, to influence an airflow (LS), a further air guide element (9), which is designed independently of the air guide element (8), is arranged on the underbody (3), wherein the further air guide element (9) is arranged at least close to an element end (13) of the air guide element (8) which is designed to face an underbody center (12) of the underbody (3) or in an underbody area (22) formed between the wheel housing (6) in the front area (4) and the wheel housing (6) in the rear area (5), wherein the further air guide element (9) is arranged movably on the underbody (3).

Description

[0001] The invention relates to a motor vehicle with a motor vehicle body and with an underbody according to the preamble of claim 1.

[0002] Motor vehicles with a car body are generally known. The interior of the car body forms a so-called Helmholtz resonator, which creates an acoustic phenomenon within the body in the form of a so-called "aero-boom." Reducing, or preferably eliminating, this "aero-boom" leads to a conflict between the aerodynamics of the vehicle, and thus its lift and drag coefficients, and the resulting acoustics, particularly within the car body.

[0003] Patent DE 10 2023 130 581 B3 discloses a motor vehicle with a motor vehicle body, wherein several wheel spoilers are arranged on an underbody of the motor vehicle body, wherein the wheel spoilers are curved backwards on the inside and several vortex generators are provided on the underbody in extension of the wheel spoilers.

[0004] Patent DE 10 2017 128 791 B4 discloses a motor vehicle with a motor vehicle body, wherein an air guide element arranged in front of a vehicle wheel of the motor vehicle body is adjustable and can be pivoted about a pivot axis between a retracted and an extended position.

[0005] Patent DE 10 2014 111 073 B4 discloses a front section of a motor vehicle which has an adjustable air guide element at each of its two front section corners.

[0006] Patent DE 10 2010 037 616 B4 discloses a motor vehicle with an adjustable air guide element, which is arranged in front of a vehicle wheel in an underbody of a motor vehicle body and is arranged to pivot in the direction of a roadway.

[0007] Patent US 10,099,731 B2 describes a wheel spoiler mounted on the underbody of a motor vehicle, which is pivotably mounted.

[0008] Patent EP 3 390 209 B2 discloses a motor vehicle with an air guide element adjustable between an extended and a retracted position, which is arranged in front of a vehicle wheel in the direction of travel.

[0009] Patent EP 3 554 927 B1 describes a motor vehicle with a wheel spoiler, which is arranged on the underbody of the motor vehicle's body and in the direction of travel in front of a vehicle wheel, wherein the wheel spoiler is mounted on the underbody in such a way that the wheel spoiler gives way or pivots away when subjected to a load from an object.

[0010] Patent EP 3 416 874 B1 discloses a wheel spoiler adjustable between an extended and a retracted position, which is arranged on the underbody and in front of a vehicle wheel in the direction of travel.

[0011] The patent application DE 10 2016 010 321 A1 describes a motor vehicle with an air guide element which is adjustable between an extended and a retracted position, wherein the air guide element is arranged on an underbody of a body of the motor vehicle in the direction of travel in front of a vehicle wheel, such that the air guide element is a wheel spoiler or a front spoiler.

[0012] The object of the present invention is to provide an improved motor vehicle comprising a motor vehicle body and an underbody.

[0013] The object of the invention is achieved by means of a motor vehicle comprising a motor vehicle body and an underbody with the features of claim 1. Advantageous embodiments with expedient and non-trivial further developments of the invention are specified in the respective dependent claims.

[0014] A motor vehicle according to the invention, comprising a motor vehicle body and an underbody, has a left-side wheel arch and a right-side wheel arch in both a front and a rear section. At least one of the wheel arches has an air guide element formed in the direction of travel in front of a wheel housed in the wheel arch. According to the invention, a further air guide element, which is formed independently of the first air guide element, is arranged on the underbody to influence airflow. The further air guide element is arranged at least near an end of the first air guide element that faces the center of the underbody or in an underbody section formed between the wheel arch in the front section and the wheel arch in the rear section. The further air guide element is movably arranged on the underbody.

[0015] Low-frequency pulsations in the range below 30 Hz can occur periodically on aerodynamically effective add-on parts of the vehicle body, such as an air guide element in the form of a wheel spoiler, particularly if the vehicle body has a very smooth underbody. Airflow around the wheel spoiler and wheels leads to separation, which can generate vortices. In particular, the superposition of vortices at the front and rear of the vehicle body can lead to significant vortex growth, and the coupling of pressure fluctuations via the vehicle body can produce a so-called "aero-boom." This acoustic phenomenon can be advantageously reduced by using an additional air guide element, i.e., one arranged on the underbody in addition to a wheel spoiler.If the additional air guide element, which can also be called a vortex generator, is designed to be movable and its position relative to the underbody can be changed during operation, the advantage is that it can counteract increasing lift and drag coefficients even while the vehicle is in operation, especially at high speeds. In other words, changing the position of the additional air guide element during operation can influence the vehicle's aerodynamics. This can further reduce the vehicle's fuel consumption.

[0016] For example, low-frequency pressure fluctuations also increase with increasing vehicle speed. This means that lift and drag coefficients also rise with increasing speed, although the movable additional air guide elements can reduce these low-frequency pressure fluctuations. The strength of the pressure fluctuations also depends on the position of the cooling air flaps and the wheels, so an adaptive design of the additional air guide elements offers the possibility of only moving them into their effective position when the vehicle is in a corresponding operating condition in which influencing the aerodynamics is necessary.

[0017] The additional air guide element is advantageous - movable translationally along a vertical axis of the vehicle body, or - pivotable about a pivot axis whose direction of extension is formed along a longitudinal body axis and / or along a transverse body axis, or - Rotatable around a pivot axis extending along the vertical axis of the body, mounted on the underbody. These are alternative configurations which can potentially be combined.

[0018] Advantageously, the additional air guide element is wedge-shaped, thus forming a wedge. In particular, one tip of the wedge-shaped additional air guide element is oriented at least towards the front area when the additional air guide element is in its operating position.

[0019] Provided the additional air guide element is translationally movable along the vehicle's vertical axis, the underbody has a gap to accommodate it. This allows the additional air guide element to be easily and advantageously adjusted along the vehicle's vertical axis to its effective height, and thus to its effective position. It should be noted that the effective position is the position of the additional air guide element at which it achieves the desired effect on aerodynamics. The effective height is therefore the relevant height of the additional air guide element for realizing the desired effect.

[0020] Provided that the further air guide element can be pivoted about the pivot axis, the direction of extension of which is formed along a longitudinal body axis and / or along a transverse body axis, the pivot axis extends along a first element edge of the further air guide element formed opposite an underbody surface of the underbody, so that it can be easily pivoted to a parallel arrangement with the underbody, or in other words, laid flat against the underbody, and thus does not or only insignificantly influence the airflow.

[0021] If the additional air guide element is rotatable about the axis of rotation extending along the vehicle's vertical axis, the axis of rotation extends along a third element edge, which is also designed to extend along the vehicle's vertical axis. This allows the additional air guide element to be rotated in a simple alternative manner.

[0022] To adapt the airflow and thus the resulting acoustics to a shape of the underbody and / or wheel arches, the additional air guide element can be concave, convex or S-shaped relative to the air guide element.

[0023] A second element edge of the further air guide element, facing away from the underbody, can also deviate from a straight shape in order to achieve a further reduction of low-frequency pressure fluctuations.

[0024] To avoid additional turbulence, it is advantageous if the maximum element height of the additional air guide element is at most as large as the maximum height of the air guide element.

[0025] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. Identical or functionally equivalent elements are assigned identical reference numerals. The figures show: Fig. 1. A motor vehicle in a bottom view with a motor vehicle body and with an underbody according to the state of the art without an air guide element, with generated sound pressure waves. Fig. 2 in a bottom view the motor vehicle according to the state of the art with an air guide element, with generated sound pressure waves, Fig. 3 in a schematic representation an underbody of a motor vehicle according to the invention with a motor vehicle body and with the underbody according to a first embodiment, comprising the air guide element and a further air guide element in a) a fully extended position and b) a fully retracted position, Fig. 4 in a perspective view the motor vehicle according to a first embodiment having the further air guide element in a fully extended position, Fig. 5 in a perspective view the motor vehicle according to the first embodiment, having the further air guide element in a first intermediate position, Fig. 6 in a perspective view the motor vehicle according to the first embodiment, having the further air guide element in a second intermediate position, Fig. 7 in a perspective view the motor vehicle according to the first embodiment, having the further air guide element in a fully retracted position, Fig. 8 in a schematic representation the underbody of the motor vehicle according to a second embodiment, comprising the further air guide element in a) a fully folded-in position and in b) a fully unfolded position, Fig. 9 in a perspective view the motor vehicle according to the second embodiment, having the further air guide element in its fully unfolded position, Fig. 10 in a perspective view the motor vehicle according to the second embodiment, having the further air guide element in its fully folded-in position, Fig. 11 in a schematic representation the underbody of the motor vehicle according to a third embodiment, having the further air guide element in a position angled relative to the air guide element according to a), fully folded-in position according to b) and a fully unfolded position according to c). Fig. 12 in a perspective view the motor vehicle according to the third embodiment, having the further air guide element in its fully extended position, and Fig. 13 in a perspective view the motor vehicle according to the third embodiment, having the further air guide element in its fully folded position.

[0026] A motor vehicle 1 according to the state of the art, as described in the Fig. 1 and Fig. Figure 2 shows a motor vehicle body 2 with a flat underbody 3, wherein the motor vehicle body 2 has a left-side and a right-side wheel housing 6 in a front area 4 facing a front 15 of the motor vehicle body 2 and in a rear area 5 facing a rear 16 of the motor vehicle body 2. The wheel housing 6 is designed to accommodate a rotatably mounted wheel 7 of the motor vehicle 1.

[0027] In the Fig. 1 and Fig. Figure 2 illustrates the motor vehicle 1 in a bottom view according to the prior art, wherein an airflow LS is generated by a wind tunnel, which leads into the Fig. 1 and Fig. This leads to 2 visualized sound pressure waves. In the illustration according to Fig. 1. Pressure fluctuations occur particularly in the area of ​​the wheel arches 6, which are formed in the front area 4. It should be mentioned here that in the two Fig. 1 and Fig. Two fields with a high point density exhibit higher sound pressure levels than fields with a lower point density.

[0028] The motor vehicle 1 according to the prior art has air guide elements 8 in the form of wheel spoilers curved in the direction of travel F to improve the aerodynamic requirements of the motor vehicle 1, which are arranged in front of the respective wheels 7 in the direction of travel F, wherein a superposition of separations in the front area 4 and rear area 5 leads to an increased growth of pressure fluctuations, as in Fig. 2 is shown.

[0029] It should be mentioned at this point that the flat underbody 3 is essentially a smooth underbody 3 along which the airflow LS could flow essentially unhindered, provided that the wheel arches 6 did not exist.

[0030] Furthermore, it should be mentioned that the air guide elements 8 are generally attached to the vehicle body 2, in particular to an edge bounding the corresponding wheel housing 6. Thus, they could also be described as being arranged in or on the wheel housing 6, since the wheel housing 6 as such forms a receiving space for the wheel 7 bounded by the vehicle body 2.

[0031] In Fig. Figure 3 illustrates a schematic diagram of the underbody 3 of a motor vehicle 1 according to a first embodiment of the invention, wherein the air guide element 8 is designed in the form of a rectangle. To influence the airflow LS, a further air guide element 9, which is designed independently of the air guide element 8, is arranged on the underbody 3.

[0032] The additional air guide element 9 is wedge-shaped, specifically triangular, and in particular acute triangle, with one apex 10 of the additional air guide element 9 facing the front 15 on the underbody 3. The additional air guide element 9 is located near an end 13 of the air guide element 8 on the underbody 3, the latter facing a center point 12 of the underbody 3. It could also be located directly adjacent to the air guide element 8 on the underbody 3, thus without creating an air gap between the air guide element 8 and the additional air guide element 9. Alternatively, it could be positioned further away from the air guide element 8 along a transverse body axis Y in the direction of the center point 12 of the underbody.

[0033] Alternatively, it could be arranged further away from the air guide element 8 on the underbody 3 along a longitudinal body axis X. In other words, it could be located in an underbody area 22 formed between the wheel arch 6 in the front region 4 and the wheel arch 6 in the rear region 5. In the present first embodiment, two further air guide elements 9 are attached to the underbody 3 in series with respect to the air guide element 8, with one of these further air guide elements 9, facing the front 15, being positioned close to the air guide element 8. Likewise, additional air guide elements 9 could be attached to the underbody 3 in series.

[0034] The further air guide element 9 is movably designed on the underbody 3. This means that it is not rigidly arranged on the underbody 3, but according to the first embodiment of the motor vehicle 1 according to the invention, it is translationally movable along a vertical axis Z of the motor vehicle body 1.

[0035] For this purpose, the underbody 3 has a gap 11, which is designed to accommodate the further air guide element 9, and into which it can be arranged to project completely or partially.

[0036] The further air guide element 9, preferably designed in the form of a wedge, has a first element edge 14 which extends along the underside surface 17. It has a second element edge 20 which is directed away from the first element edge 14, and it has a third element edge 21 which connects the two element edges 14, 20 and which is directed away from the tip 10.

[0037] In a fully extended position, as shown in a) the Fig. As illustrated in Figure 3, the further air guide element 9 is arranged to project completely out of the gap 11 above a first underfloor surface 17 of the underfloor 3 which is designed to face a driving floor.

[0038] A fully retracted position of the further air guide element 9, in which the further air guide element 9 is not or only insignificantly exposed to the airflow LS, is described in b) of the Fig. Figure 3 illustrates this. The additional air guide element 9 is arranged at least flush with the first underbody surface 17, whereby a negligible airflow could be formed. Likewise, in the fully retracted position, the additional air guide element 9 could also be spaced away from the first underbody surface 17, thus being set back relative to it in a direction facing away from the underbody surface 17.

[0039] In the Fig. 4, Fig. 5, Fig. 6 to Fig. Figure 7 illustrates the motor vehicle 1 according to the first embodiment with the additional air guide element 9 arranged in various positions. The additional air guide element 9 is not only shown in its fully extended position, as in Fig. 4 is illustrated, or in its fully retracted position, as in Fig. As illustrated in section 7, it is not only possible to arrange it in numerous intermediate positions between the fully extended and fully retracted positions, but it can also be arranged in numerous intermediate positions, as shown in the Fig. 5 and Fig. 6 is shown.

[0040] In Fig. Figure 5 shows the further air guide element 9 not fully extended, and is therefore in a first intermediate position, whereas in a position as shown in Fig. As shown in Figure 6, in the second intermediate position the further air guide element 9 is extended less than in the first intermediate position. However, it is not yet fully retracted in the second intermediate position. Between these in the Fig. 4, Fig. 5, Fig. 6 to Fig. In addition to the positions of the further air guide element 9 shown in the 7 illustrations, it can be arranged in numerous other intermediate positions. It can thus be adapted to numerous operating states of the motor vehicle 1, wherein, according to the first embodiment, the further air guide element 9 is preferably arranged transversely to the underbody surface 17, and in particular perpendicularly to the underbody surface 17.

[0041] The arrangement of the further air guide element 9 relative to the longitudinal axis X of the body can be perpendicular to it or parallel to it.

[0042] In Fig. Figure 8 illustrates in a schematic representation the underbody 3 of the motor vehicle 1 according to the invention with the motor vehicle body 2 according to a second embodiment, having the further air guide element 9 in a) a fully folded position and in b) a fully unfolded position.

[0043] The additional air guide element 9 has a pivot axis 18 about which it is pivotably arranged on the underbody 3. In this second embodiment as well, the additional air guide element 9 is designed in the form of a wedge, as already described above. The pivot axis 18 extends along the first element edge 14 of the additional air guide element 9, which, in the fully extended position, faces the underbody surface 17.

[0044] In the present embodiment, the first element edge 14 extends along the longitudinal axis X of the vehicle body. However, it could also extend along both the longitudinal axis X and the transverse axis Y of the vehicle body, thus perpendicular to the longitudinal axis X. Therefore, the direction of extension of the pivot axis 18 could be configured along a longitudinal axis X and a transverse axis Y of the vehicle body.

[0045] The additional air guide element 9 can be pivoted about the pivot axis 18 so as to rest against the underbody surface 17, or it can be pivoted so that it is angled at 90° relative to the underbody surface 17. It could also be pivoted into further intermediate positions between the fully folded position and the fully unfolded position.

[0046] The further air guide element 9 could be designed to be flush with the underfloor surface 17 in its fully folded position. However, it could also be designed as in a) of the Fig. 8 illustrates that the subfloor surface 17 should be designed to overlap.

[0047] Furthermore, according to the second embodiment, the additional air guide element 9 could be arranged in its fully folded position extending parallel to the underfloor surface 17.

[0048] Thus, in Fig. Figure 9 shows a perspective view of the underbody 3 of the motor vehicle 1 according to the invention with the motor vehicle body 2 according to the second embodiment, showing the further air guide element 9 in its fully unfolded position, and in Fig. Figure 10 shows the motor vehicle 1 according to the invention with the motor vehicle body 2 according to the second embodiment, having the further air guide element 9 in its fully folded position, in which it is arranged lying against the underbody surface 17.

[0049] The second embodiment also has the further air guide element 9 located close to, in particular directly adjacent to, the air guide element 8 at its element end 13, wherein in this embodiment at least a second further air guide element 9 is arranged serially to the further air guide element 9 on the underbody 3.

[0050] In Fig. Figure 11 illustrates a schematic diagram of the underbody 3 of the motor vehicle 1 according to the invention, comprising the motor vehicle body 2 according to a third embodiment, with the further air guide element 9 in a position angled relative to the air guide element 8 according to a), a fully folded-in position according to b), and a fully unfolded position according to c). That is, the further air guide element 9 has an axis of rotation 19, which extends along the third element edge 21, which is designed to extend along the vertical axis Z of the body, about which it is rotatably arranged, in particular rotatably relative to the air guide element 8.

[0051] The further air guide element 9 is designed to be rotatable almost completely through 360° about the axis of rotation 19, up to a stop in the form of the air guide element 8. Starting from the axis of rotation 19, it can be arranged facing the front area 4 or the rear area 5, and it can also be positioned at various angles α to the air guide element 8. This is shown in an illustration in Fig. 12 is positioned at an angle α of 90° relative to the air guide element 8 and facing the front 15. The further air guide element 9 is shown as an example, as in Fig. Figure 13 shows the air guide element 8 positioned at an angle α of 0° relative to the air guide element. It is oriented towards the front 15, but could also be oriented towards the rear 16, thus rotated by an angle α of almost 360°. Numerous intermediate positions are conceivable.

[0052] It should be noted that the additional air guide element 9 is plate-shaped and has a first element surface 23 and a second element surface 24 facing away from the first element surface 23. If the additional air guide element 9 is pivotable, this means that one of the two element surfaces 23, 24 can be arranged parallel to the base 3. If the additional air guide element 9 is rotatable about the axis of rotation 19, the element surfaces 23, 24 can be positioned adjacent to, or at least opposite, the air guide element 8, and thus covered by it.

[0053] The further air guide element 9 is advantageously wedge-shaped. However, it could also have other shapes, for example, be rectangular. Advantageously, the value of its maximum element height HE is not greater than the value of the maximum height H of the air guide element 9. In its operating position, which does not correspond to a fully retracted or fully folded position, the tip 10 is preferably oriented towards the front area 4.

[0054] The first edge 14 of the additional air guide element 9 faces the underfloor surface 17. The second edge 20, which faces away from the first edge 14, extends in a straight line in the described embodiments. However, the second edge 20 could also be designed such that the element height HE does not decrease linearly, but could instead have a wave-like decrease. Likewise, the additional air guide element 9 could be concave, convex, or S-shaped relative to the air guide element 8. Numerous shapes are conceivable.

[0055] It should be mentioned that the height H of the air guide element 8 corresponds to a maximum of 2 / 3 of the value of the underbody clearance of the vehicle body 2, which extends along a vertical axis Z of the vehicle body 2.

[0056] The additional air guide element 9 can also be called a vortex generator and is designed in addition to the air guide element 8, which is a wheel spoiler and is therefore arranged in front of the wheel 7 in the direction of travel. Reference symbol list 1 motor vehicle 2 Motor vehicle body 3 Underbody 4 Front area 5 Rear area 6 Wheel arch 7 wheel 8 Air guide element 9. Additional air guide element 10 Top 11 column 12 Underbody center 13 element ends 14 First element edge 15 Front 16 Rear 17 Subfloor area 18 Swivel axis 19 axis of rotation 20 Second element edge 21 Third element edge 22 Underbody area 23 First element surface 24 Second element surface F Direction of travel H height HE element height LS airflow X Body longitudinal axis Y body transverse axis Z Body vertical axis α angle

Claims

Motor vehicle (1) with a motor vehicle body (2) and with an underbody (3), wherein the motor vehicle body (2) has a left-side wheel housing (6) and a right-side wheel housing (6) in a front area (4) and a rear area (5), and wherein at least one of the wheel housings (6) has an air guide element (8) formed in the direction of travel (F) in front of a wheel (7) received in the wheel housing (6), characterized in that, in order to influence an airflow (LS), a further air guide element (9), which is formed independently of the air guide element (8), is arranged on the underbody (3), wherein the further air guide element (9) is arranged at least close to an element end (13) of the air guide element (8) formed towards an underbody center (12) of the underbody (3) or in an underbody area (22) formed between the wheel housing (6) in the front area (4) and the wheel housing (6) in the rear area (5),wherein the further air guide element (9) is movably arranged on the underbody (3), and wherein the further air guide element (9) is arranged to be: - movable translationally along a vertical axis (Z) of the vehicle body (1), or - pivotable about a pivot axis (18) whose direction of extension is formed along a longitudinal axis (X) of the body and / or along a transverse axis (Y) of the body, or - rotatable about a rotation axis (19) which extends along the vertical axis (Z) of the body on the underbody (3). Motor vehicle (1) according to claim 1 , characterized in that the further air guide element (9) is wedge-shaped, in the form of a wedge. Motor vehicle (1) according to claim 2, characterized in that a tip (10) of the wedge-shaped further air guide element (9) is oriented in an effective position of the further air guide element (9) at least in the direction of the front area (4). Motor vehicle (1) according to claim 2 or 3, characterized in that, if the further air guide element (9) is translationally movable along the body vertical axis (Z), the underbody (3) has a gap (11) for receiving the further air guide element (9). Motor vehicle (1) according to claim 2 or 3, characterized in that, if the further air guide element (9) is pivotable about the pivot axis (18), the direction of extension of which is formed along a longitudinal body axis (X) and / or along a transverse body axis (Y), the pivot axis (18) extends along a first element edge (14) of the further air guide element (9) formed opposite an underbody surface (17) of the underbody (3), or, if the further air guide element (9) is rotatable about the axis of rotation (19), which extends along the vertical body axis (Z), the axis of rotation (19) extends along a third element edge (21), which is formed extending along the vertical body axis (Z). Motor vehicle (1) according to one of the preceding claims, characterized in that the further air guide element (9) is concave or convex or S-shaped relative to the air guide element (8). Motor vehicle (1) according to one of the preceding claims, characterized in that a second element edge (20) of the further air guide element (9) facing away from the underbody (3) is designed in a manner deviating from a straight shape. Motor vehicle (1) according to one of the preceding claims, characterized in that a maximum element height (HE) of the further air guide element (9) is at most as large as a maximum height (H) of the air guide element (8).

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