Motor vehicle with a diffuser arranged in its rear area

Abstract

Motor vehicle (2), with an underbody (3) which rises to form a diffuser (5) in the rear area (1) of the vehicle (2), with an air guide element (6) arranged in the area of ​​the diffuser (5), which can be pivoted into different positions by means of an adjustment mechanism (9) mounted fixed to the body, characterized in that the air guiding element (6) has an air separation edge (7), wherein the adjustment mechanism (9) is connected to the air guiding element (6), the air guiding element (6) is pivotably mounted by means of a one-piece film hinge (8) extending over the length of the air guiding element (6), made of an elastic material, and mounted so as to be fixed to the body, wherein the film hinge (8) is mounted so as to be fixed to the body in front of the air guiding element (6) with respect to an air flow beneath the underbody (3).

Description

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

[0002] By means of such a diffuser, which rises towards the rear of the vehicle, the air flowing between the underbody and the road surface is accelerated upwards, and the resulting lower pressure increases the downforce acting on the vehicle. This is advantageous at high vehicle speeds. However, this increases driving resistance and, consequently, fuel consumption. In driving conditions where this downforce is not required, the air deflector is moved from a retracted position to an extended position, reducing the downforce and thus increasing the lift force, but reducing air resistance compared to the effective position with the air deflector retracted.

[0003] DE 10 2013 105 843 A1 discloses a motor vehicle according to the preamble of claim 1. The motor vehicle has an air deflector element below the underbody, which rises like a diffuser in the opposite direction of travel, which can be extended from an upper rest position downwards to the vehicle's contact surface. In an extended position, this element can be pivoted into several positions with different angles by means of an adjustment mechanism, specifically a holding and adjusting device, about a rotational axis arranged centrally and extending transversely to the air deflector element.

[0004] A motor vehicle with a rear diffuser is also described in DE 10 2013 105 842 A1.

[0005] US 2015 / 0 232 138 A1 discloses a motor vehicle with an underbody and with an air guide element arranged in the area of ​​the underbody, which can be pivoted into different positions.

[0006] DE 10 2008 061 793 A1 discloses a motor vehicle with a front spoiler which engages a supporting part via a film hinge.

[0007] DE 36 13 301 A1 describes a side panel for passenger cars or station wagons. The side panel has an upper, lateral, dimensionally stable section, to which further sections are connected downwards and inwards via predetermined bending points in the form of film hinges. The side panel can be extended and retracted using an adjusting element. At higher driving speeds, the side panel is extended, whereas when the vehicle is stationary, it is often visually disruptive and is therefore retracted.

[0008] The object of the present invention is to develop a motor vehicle of the type mentioned above in such a way that the aerodynamic properties of the vehicle can be controlled with simple and robust mounting and simple design of the air guide element.

[0009] The object is achieved by a motor vehicle which is designed according to the features of claim 1.

[0010] In the motor vehicle according to the invention, it is provided that the air guiding element is pivotably mounted by means of a film hinge mounted fixed to the body.

[0011] When the air guide element is in the extended position, the trailing edge of the air guide element causes air flowing along the underbody into the diffuser area to break off at the trailing edge and thus swirl, creating a non-laminar, turbulent flow in the diffuser area that counteracts the effect of the diffuser. This effect can thus be achieved using a very simply designed air guide element.

[0012] The pivotable mounting of the air guide element according to the invention by means of a film hinge on the body side represents, on the one hand, a structurally particularly simple type of mounting, and on the other hand, a robust mounting. In addition, this design is particularly cost-effective. Due to the design of the mounting as a film hinge, the air guide element is not mounted around a precise axis of rotation, but rather the pivotability of the air guide element in relation to the body results from the flexible property of the film hinge. The film hinge stabilizes the air guide element connected to it. This stabilized mounting of the air guide element via the film hinge and the engagement of the adjustment mechanism on the air guide element ensures sufficient, functionally reliable stability of the air guide element in relation to the body.of the underbody in all swivel positions of the air guide element, whereby the term underbody is understood not only to mean the underbody as such, but also an underbody cover.

[0013] The use of a film hinge allows for a tolerance-based mounting of the air deflector relative to the body or a recess in the underbody, while also allowing for a certain degree of flexibility in the mounting of the air deflector. This means that if the vehicle bottoms out or an object, such as a stone, comes into contact with the air deflector while driving, especially when the air deflector is extended, the film hinge can absorb pressure surges. If the air deflector were mounted on a rigid axle, this would damage the air deflector or its bearing. The film hinge is also immune to contamination, particularly from snow, ice, and water. The film hinge is also not subject to corrosion.

[0014] According to a special design of the air guide element, it is intended to extend in the width direction of the vehicle. In the usual X, Y, Z coordinate system, this width direction is understood to be the Y direction, where X is the longitudinal direction of the vehicle and Z is the vertical direction of the vehicle. In particular, the air guide element extends across the width of the diffuser. If the air guide element is extended, this disrupts the flow in the diffuser across its entire width.

[0015] The film hinge extends the length of the air guide element. When the air guide element is arranged in the Y direction, the film hinge extends the length of the air guide element in the Y direction. The film hinge is a one-piece construction.

[0016] The particular advantage of extending the film hinge over the length of the air guide element and the one-piece design of the film hinge is that it ensures a seal between the air guide element and the underbody, especially when the air guide element is retracted. This permanently prevents dirt from penetrating the area of ​​the body where the retracted air guide element is located.

[0017] The film hinge is made of an elastic material. It is, in particular, a rubber-elastic material. The film hinge is designed, for example, as a rubber strip with a thickness of 2 to 3 mm, which is firmly connected to the body, for example by gluing or riveting it to a body component or the underbody, or by injection molding it onto it. The film hinge can be connected to the air deflector in a corresponding manner. The film hinge is mounted in front of the air deflector, in relation to the air flow beneath the underbody. Due to this mounting, forces transmitted to the air deflector as a result of air influence can be effectively transmitted to the body via the film hinge.In addition, a gap between the extended air guide element and the underbody can be bridged by means of the film hinge, which is particularly advantageous with regard to the problem of dirt.

[0018] According to a particularly advantageous structural design, the air guide element is designed as a rod-shaped hollow body. This utilizes an inexpensive starting component, which is produced primarily by extrusion. This component can be easily designed with the tear-off edge.

[0019] Preferably, the air guide element is retracted into a recess in the underbody in a first end position and extended from this recess in a second end position. In the second end position, the air guide element is arranged below the underbody; depending on the variable extension position of the air guide element, a more or less turbulent air flow can be generated. In particular, it is provided that the air guide element is arranged perpendicular to the underbody in the second end position. In this position, the greatest turbulence effect is generated by the air guide element.

[0020] The air guide element is arranged in particular directly in front of the diffuser, thus directly upstream of the diffuser.

[0021] According to a preferred development, the air guide element has a guide surface which, in the first end position of the air guide element, forms a lower side of the air guide element and is flush with the underbody at the bottom. This guide surface is arranged perpendicular to the underbody in the second end position of the air guide element. A lower edge of the guide surface in this position forms the separation edge of the air guide element.

[0022] The film hinge is connected, in particular, to the air guide element in the area of ​​the guide surface. It is considered particularly advantageous if the air guide element is adjusted using a single adjustment mechanism acting on one area of ​​the air guide element. A single adjustment mechanism is sufficient because the film hinge stabilizes the air guide element due to its bearings. It is therefore unnecessary to provide multiple adjustment mechanisms spaced apart from one another, which thus engage the air guide element along its length and precisely guide its pivoting.

[0023] The adjustment mechanism is particularly simple in design if it has two levers connected by a hinge. One lever can be pivoted by means of an actuator, in particular an electric actuator, and the other lever is pivotally connected to the air guide element. In particular, the pivot axes of the levers and the pivot axis of the film hinge are arranged parallel to each other. Since a film hinge does not have an exact pivot axis, in reality the pivot axes of the levers are arranged parallel to each other, and the pivot axis of the film hinge is arranged approximately parallel to the pivot axes of the levers.

[0024] Further features of the invention emerge from the subclaims, the attached drawing and the description of the preferred embodiment shown in the drawing, without being limited thereto.

[0025] It shows: Fig. 1 a rear area of ​​a partially depicted SUV passenger car, seen obliquely from below and behind, Fig. 2 a longitudinal center section (section in the XZ plane) of the Fig. 1 shown vehicle in the area of ​​its diffuser and air guide element, Fig. 3 in a spatial view, seen obliquely from above, functional parts that interact with the air guide element, Fig. 4 a modified embodiment of the invention in a sectional view according to the plane XZ.

[0026] The Fig. 1 and Fig. 2 illustrate a rear area 1 of a vehicle 2 with an underbody 3 shown only for a partial area of ​​the underbody. In the rear area 1, a diffuser 5 is illustrated, which is arranged between two pairs of exhaust tailpipes 4 and rises in the rear area of ​​the vehicle opposite to the (forward) direction of travel of the vehicle. An air guide element 6 is arranged in front of the diffuser 5 in the direction of travel. This extends in the width direction Y of the vehicle 2, specifically across the width of the diffuser 5, and thus also across the free length between the two pairs of exhaust tailpipes 4. The air guide element 6 has an air separation edge, hereinafter referred to as separation edge 7, and is pivotably mounted by means of a film hinge 8 mounted fixed to the body. The air guide element 6 can be pivoted into different positions by means of a single adjustment mechanism 9 mounted fixed to the body. The adjustment mechanism 9 is connected to the air guide element 6.

[0027] In the Fig. 1 and Fig. 2 shows the air guide element 6 in its pivoted-in position. In this position, it is pivoted into two body-mounted receptacles 10.

[0028] Fig. Figure 3 illustrates the detailed structure of the components relevant to understanding the invention, shown with the air guide element 6 pivoted in. The two receptacles 10 are firmly connected to the body via holders 11 and 12. Furthermore, the two receptacles 10 and the one holder 12 are firmly connected to a plate 13, in particular a sheet metal, wherein the plate 13 functionally forms a component of the underbody 3. The plate 13 is mounted in a fixed manner to the body and is screwed to the body, in particular in the area of ​​two holes 14.

[0029] The air guide element 6 is mounted in the plate 13 via the film hinge 8. The film hinge 8 is designed as a rubber plate with a thickness of, for example, 2.5 mm, with the end running in the direction of travel (in direction X) being clamped between a clamping strip 15 connected to the plate 13 and the plate 13. In addition, the film hinge 8 can be glued to the plate 13. A small gap is formed between the clamping strip 15 or the plate 13 and the air guide element 6, which gap is bridged by the film hinge 8. The film hinge 8 is inserted into a recess 16 of the air guide element 6 and glued there to the air guide element 6. On the side of the air guide element 6 facing away from the film hinge 8, the air guide element 6 is connected to a reinforcing strip 17. In the area of ​​the holder 12, a bearing element 18 is connected to this for the articulated reception of a lever 19 of the adjustment mechanism 9.A further component of the adjustment mechanism 9 is a further lever 20, which can be pivoted about an axis 21 relative to the lever 19 and is fixedly connected to a shaft 22 rotatably mounted in the holder 12. This shaft 22 can be driven by means of an electric actuator 23, which is mounted in the holder 12. The axis about which the lever 19 can be pivoted in the bearing holder 18 is designated by the reference numeral 24. When the electric actuator 23 is actuated, the shaft 23 and thus the lever 20 are pivoted, with the lever 20 acting on the lever 19 in an articulated manner and the joint between the lever 19 and the bearing holder 18 causing the air guide element 6 to pivot, such that in one direction of rotation of the electric actuator 23 the air guide element 6 is extended and in the other direction of rotation it is retracted.

[0030] Fig. Figure 4 illustrates in a section in the plane XZ a modified design of the adjustment mechanism 9 in that the bearing receptacle 18 and the levers 19, 20 are arranged on the other side of the holder 12 and the electric actuator 23 is arranged on the other side, relative to its position according to Fig. 3.

[0031] In particular, due to the presentation of the Fig. 3 and Fig. 4, relevant details emerge: The film hinge 8 is a single piece. It is mounted in front of the air guide element 6, in relation to the air flow beneath the underbody, which occurs in the opposite direction of arrow X, and is fixed to the body, specifically via the plate 13. The air guide element 6 is designed as a rod-shaped hollow body. As can be seen in particular from the illustration of the Fig.As can be seen in Figure 4, the air guide element 6 is retracted into the recess in the underbody in the first end position and extended out of this recess in the second end position, wherein the air guide element 6 is arranged below the underbody 3 in the second end position. In this second end position, the air guide element 6 is arranged perpendicular to the underbody 3.

[0032] The air guide element 6 has a guide surface 25, which in the first end position of the air guide element 6 forms a bottom side of the air guide element 6 and is flush with the underbody 3. In contrast, in the second end position of the air guide element 6, the guide surface 25 is arranged perpendicular to the underbody 3. In this second end position, the lower edge of the guide surface 25 forms the tear-off edge 7. The film hinge 8 is connected to the air guide element 6 in the region of the guide surface 25.

[0033] Two stops 26 limit the pivoting angle of the lever 20 and thus define the two end positions of the air guide element 6.

Claims

[1] Motor vehicle (2), with an underbody (3) which rises to form a diffuser (5) in the rear area (1) of the vehicle (2), with an air guide element (6) arranged in the area of the diffuser (5), which can be pivoted into different positions by means of an adjustment mechanism (9) mounted fixed to the body, characterized by , that the air guiding element (6) has an air separation edge (7), wherein the adjustment mechanism (9) is connected to the air guiding element (6), the air guiding element (6) is pivotably mounted by means of a film hinge (8) extending over the length of the air guiding element (6), made of an elastic material, is one-piece and is mounted in a way that is fixed to the body, wherein the film hinge (8) is mounted in a way that is fixed to the body in front of the air guiding element (6) with respect to an air flow beneath the underbody (3). [2] Vehicle according to claim 1, characterized bythat the air guiding element (6) extends in the width direction (Y) of the vehicle (2). [3] Vehicle according to claim 2, characterized by that the air guide element (6) extends over the width of the diffuser (5). [4] Vehicle according to one of claims 1 to 3, characterized by that the air guiding element (6) is designed as a rod-shaped hollow body. [5] Vehicle according to one of claims 1 to 4, characterized by that the air guiding element (6) is retracted into a recess in the underbody (3) in a first end position and is extended out of this recess in a second end position, wherein the air guiding element (6) is arranged below the underbody (3) in the second end position. [6] Vehicle according to claim 5, characterized by that the air guiding element (6) is arranged perpendicular to the underbody (3) in the second end position. [7] Vehicle according to claim 5 or 6, characterized byin that the air guiding element (6) has a guiding surface (25) which, in the first end position of the air guiding element (6), forms a lower side of the air guiding element (6) and terminates at the bottom with the underbody (3), wherein the guiding surface (25) is arranged perpendicular to the underbody (3) in the second end position of the air guiding element (6), and a lower edge of the guiding surface (25) in this position forms the tear-off edge (7). [8] Vehicle according to one of claims 5 to 7, characterized by that the film hinge (8) is connected to the air guide element (6) in the region of the guide surface (25). [9] Vehicle according to one of claims 1 to 8, characterized by that the adjustment of the air guiding element (6) is carried out by means of a single adjustment mechanism (9) acting in an area of the air guiding element (6). [10] Vehicle according to one of claims 1 to 9, characterized byin that the adjusting mechanism (9) has two levers (19, 20) which are connected to one another in an articulated manner, wherein one lever (20) is pivotable by means of an actuator (23), in particular an electric actuator, and the other lever (19) is pivotably connected to the air guiding element (6). [11] Vehicle according to claim 10, characterized by that the pivot axes (21, 22, 24) of the levers (19, 20) and the pivot axis of the film hinge (8) are arranged parallel to each other.

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