AIR DUCT FOR A PASSENGER CAR AND PASSENGER CAR

Description

[0001] The invention relates to an air guidance device for the front of a passenger car according to the preamble of claim 1. The invention further relates to a passenger car with such an air guidance device.

[0002] DE 10 2015 012 895 A1 discloses a fairing device for the front end of a passenger car, comprising a front fairing part with a front spoiler, which is limited at its lower end by a trim element. DE 36 13 303 C1 discloses an aerodynamic underbody fairing for the front end of motor vehicles that can be lowered towards the road surface. Furthermore, DE 10 2016 007 273 A1 discloses a fairing device for the front end of a passenger car.

[0003] German patent DE 31 32 341 A discloses a motor vehicle front end equipped with an air guide device comprising a front apron with a rounded leading edge, arranged below a bumper and pivotably mounted at its rear end. The front apron is pivotable between a lowered and a raised position, with a diffuser function being achieved in the lowered position.

[0004] From the De 10 2016 122 932 B4 emerges a motor vehicle which has a splitter at its front end as an aerodynamic device to increase the strength of the downforce at the front of the vehicle, which divides the airflow towards the vehicle and directs a partial airflow downwards towards a roadway.

[0005] German patent DE 10 2014 104 156 A1 discloses a generic air guidance device for the front of a passenger car. Further air guidance devices of the type discussed here are known from WO 2018 / 178579 A1 and DE 36 30 645 A1.

[0006] The object of the present invention is to create an air guidance device for the front of a passenger car and a passenger car with such an air guidance device, so that a particularly high aero-efficiency can be achieved.

[0007] This problem is solved according to the invention by an air guidance device with the features of claim 1 and by a passenger car with the features of claim 9. Advantageous embodiments with expedient further developments of the invention are the subject of the dependent claims.

[0008] A first aspect of the invention relates to an air guide device for the front, and thus for the front end, of a passenger car. This means that the passenger car, in its fully manufactured state, has the air guide device at its front. The air guide device comprises at least one air guide element. The air guide element is, for example, a fairing element or a fairing part by means of which at least one area of ​​the passenger car located at the front can be covered and thus covered downwards in the vertical direction of the vehicle. This area is, for example, a section of the engine compartment in which a drive motor, particularly an internal combustion engine, can be arranged to propel the passenger car.In particular, the engine compartment is at least partially, and especially at least predominantly and thus to more than half its length, or—as provided in a particularly preferred embodiment—completely, covered and thus clad by the air guide element in the vertical direction of the vehicle. Alternatively or additionally, at least one further component of the passenger car, in particular one designed separately from the air guide device, can be at least partially arranged in the aforementioned area, such that the component is at least partially covered and thus clad by the air guide element in the vertical direction of the vehicle. The component is, for example, a support element, in particular a longitudinal member. The support element can be part of the self-supporting body of the passenger car.Furthermore, the component may be the aforementioned drive motor of the passenger car, which is thus, for example, at least partially, in particular at least predominantly or completely, covered and therefore clad by the air guide element in the upward direction of the vehicle.

[0009] The air guide element is movable, i.e., adjustable, at least in a partial area, at least in the upward direction of the vehicle, between a raised position and a lowered position, in particular relative to the area or relative to the component.

[0010] The term "raised position" refers to the fact that the air guide element, or at least its component, is positioned closer to the component in the vehicle's vertical direction than in the lowered position. This means that in the lowered position, the air guide element, or its component, is further away from the component than in the raised position. In other words, for example, if the passenger car is stationary or rolling along a road surface that is at least substantially horizontal, the air guide element is positioned closer to the road surface in the lowered position than in the raised position. Therefore, in the raised position, the air guide element is further away from the road surface than in the lowered position.This means that the distance running in the upward direction of the vehicle between the air guide element or between the part of the air guide element and the road surface is smaller in the lowered position than in the raised position.

[0011] In order to achieve a particularly high aerodynamic efficiency of the passenger car, it is provided that the air guide device has a splitter, that the splitter and the air guide element are connected by means of at least one part made of an elastically deformable material, which becomes increasingly elastically deformable with increasing speed of the flow, and that the air guide element in the lowered position forms at least part of an airfoil profile, by means of which a downward downforce acting in the vehicle's upward direction can be generated when air flows around the airfoil profile from front to rear in the longitudinal direction of the vehicle.This means that in the invention, the airfoil profile is an inverted, i.e., upside-down, airfoil profile compared to aircraft, whose airfoils generate lift forces acting vertically upwards when air flows over them. When the airfoil profile according to the invention is oriented longitudinally from front to rear, for example, when the passenger car is traveling forwards, it generates a downward downward force acting in the upward direction of the vehicle, thus creating downforce. This effectively pulls, sucks, or pushes the passenger car downwards, or against the road surface.

[0012] The air guide device is characterized by the fact that the splitter, the elastic part, and the air guide element are mounted or supported as a single unit on the passenger vehicle, allowing for horizontal displacement in the longitudinal direction of the vehicle, and can be moved together between a position retracted into the front of the vehicle and a position extended forward. This means that it is preferably provided that the upward movement of the portion of the air guide element between these positions can be superimposed with a longitudinal movement, particularly translational, relative to the component. It is also conceivable that the unit is first extended when the air guide element is in the raised position before the air guide element is lowered.If the unit is to be retracted, the air guide element would first have to be moved into its raised position, so that the retraction of the unit can then take place.

[0013] In the air guidance device according to the invention, it is preferably provided that when the air guidance element is in the raised position, only the splitter is effective, which divides the air striking the front of the vehicle into partial airflows, with one partial airflow being directed under the vehicle. In this operating position of the air guidance device, the preferably plate-shaped air guidance element is arranged relative to the ground, in particular a road surface, such that no or no significant diffuser effect is achieved. If the air guidance element is now moved into its lowered position, the space below the air guidance element is narrowed towards the road surface, so that the airflow, or rather the partial airflow directed downwards by the splitter, of the air striking the front of the vehicle is accelerated.The air guide element now forms a diffuser, which leads to a corresponding downforce in the area of ​​the front of the vehicle.

[0014] Furthermore, according to the invention, the air guide element comprises at least one part made of an elastically deformable material, in particular a rubber-elastic material. Since this part, also referred to as the first part, is made of the elastically deformable material, in particular a rubber-elastic material, the first part itself is elastically deformable. The material is, for example, rubber or an elastomer. The part made of the elastically deformable material becomes increasingly elastically deformable with increasing airflow velocity. This means that with increasing relative velocity between the air guide element and the air flowing around the air guide element from front to rear in the longitudinal direction of the vehicle, for example during forward travel of a passenger car, the first part becomes increasingly elastically deformed.In other words, if, for example, the passenger car is initially stationary on the aforementioned roadway, and while the passenger car is stationary, the air guide element, or at least a portion thereof, is moved from its raised position (also known as the retracted position) to its lowered position (also known as the extended position), then the air guide element, or at least that portion thereof, is initially in the lowered position. If the passenger car then begins to move forward along the roadway while the air guide element is in the lowered (extended) position, then during this forward movement of the passenger car, the air guide element in the lowered position is subjected to an airflow, specifically in the longitudinal direction of the vehicle, from front to rear.As the vehicle speed increases along the road, the aforementioned relative speed between the lowered air guide element and the air flowing around it from front to rear in the longitudinal direction of the vehicle also increases. At least one force acting on the lowered air guide element, resulting from this airflow, also increases. This causes the first part to deform elastically, particularly when the vehicle speed and thus the relative speed exceed a certain limit. This elastic deformation, resulting from the increasing relative speed, causes at least a portion of the air guide element to lower from the lowered position in the vertical direction of the vehicle.This means that the elastic, in particular rubber-elastic, deformation of the first part resulting from the increasing relative speed or forward motion causes at least the subsection or air guide element to move further downwards from its lowered position in the vehicle's vertical direction, i.e., to be lowered further. This further reduces the distance between the air guide element or subsection and the road surface in the vehicle's vertical direction compared to the lowered position. This further lowering of the air guide element or at least the subsection from the lowered position preferably results solely from the airflow around the airfoil, without the air guide element or subsection being actively lowered by an actuator.

[0015] Within the scope of the invention, aerodynamic efficiency is understood to be the ratio of a passenger car's downforce to its air resistance. Particularly for high-performance vehicles driven both on public roads and on closed racetracks, a particularly high aerodynamic efficiency is desirable in order to achieve fast lap times on the track. However, if the vehicle is driven on public roads, it should be suitable for everyday use, especially with regard to its ground clearance and approach angle.Against this background, the air guide device according to the invention is a flexible system, meaning it can be deployed as needed. On the one hand, it enables particularly high downforce and thus particularly high aerodynamic efficiency for the passenger car, and on the other hand, it ensures particularly good everyday usability and efficiency for the passenger car in public road traffic. In the raised position, the distance between the air guide element and the road surface, extending upwards along the vehicle's height, is sufficiently large so that the passenger car has sufficient ground clearance. This allows the passenger car to be driven easily in everyday situations and, in particular, to be driven over objects such as curbs without collisions.In the raised position of the air guide element, only, or essentially only, the splitter is active. This splitter divides the air flowing from front to rear along the front of the vehicle during forward travel into an upper flow (vertical direction) and a lower flow (vertical direction), which, for example, flows underneath the vehicle. In the lowered and / or retracted position, the air guide element functions, for example, as a diffuser, which can generate particularly advantageous downforce. Moving or adjusting the air guide element between these positions can be done manually, for example, by the driver manually operating a control located in the vehicle's interior.

[0016] Moving the air guide element from the raised position to the lowered position results in the formation of the previously described inverted airfoil profile, also known as a wing profile. As is well known from the general prior art of conventional airfoil profiles, the airfoil accelerates the air flowing around it from front to rear in the longitudinal direction of the vehicle, and according to the invention, this acceleration is such that the downward downforce acting in the upward direction of the vehicle is generated. Due to the acceleration of the air, the pressure between the air guide device and the road surface (also referred to as the ground) decreases, for example, compared to the retracted position. This causes the passenger car to be sucked or pushed against the road surface, particularly in accordance with the Venturi effect.At the same time, the air resistance of the passenger car is reduced, especially compared to the raised position, so that a particularly high aero-efficiency can be achieved.

[0017] The air guide element can, for example, be actively moved between the lowered and raised positions by means of an actuator. It is also conceivable that at least the lowering, or in the case of a pivoting mounting, the folding down of the air guide element occurs automatically simply due to its weight, particularly after the release of a lock, latch, or other locking mechanism. Because at least the part between the splitter and the air guide element is formed from the elastically deformable material, an active and elastic aerodynamic profile is created, which is elastically deformed, i.e., deformed, by a negative pressure acting on the air guide element as the vehicle speed increases. This negative pressure results, in particular, from the fact that the airfoil profile generates the downward downforce acting in the upward direction of the vehicle.This deformation of the first part, and the resulting further lowering of at least this section from its lowered position, reduces the distance between the air guide element and the ground, thereby further increasing downforce, particularly at the front axle of the passenger car. Increasing elastic deformation of the first part of the air guide element, and thus an increasing lowering of at least this section, is associated with higher downforce and is primarily caused by increasing the vehicle's forward speed.

[0018] A further advantage of the elastic deformability of the first part of the air guide element is that it allows for effective impact management. This prevents damage to the air guide device, for example, if it comes into contact with an object located on the roadway.If, for example, an air guide element in a lowered position or in a further lowered position collides with an object located on the roadway, such that the air guide element is subjected to an upward impact, impulse, or shock acting in the direction of the vehicle's upward movement, then, because this part of the air guide element is elastically deformable, it can deflect this impact, shock, or impulse, particularly in the upward direction of the vehicle's upward movement. This deflection occurs, for example, by the elastic deformation of the first part of the air guide element. Subsequently, that is, after the collision and thus after the end of the impact, shock, or impulse, the elastically deformed part, and therefore the air guide element itself, returns to its original position from the point of impact.Excessive damage to the air guidance system can thus be effectively and easily avoided.

[0019] Overall, the invention offers the advantages of achieving a high downforce gain at the front axle compared to conventional solutions, while simultaneously reducing air resistance. This allows for particularly high aerodynamic efficiency of the passenger car. Since the elastic part of the air guide deforms increasingly with increasing vehicle speed, causing at least a portion of the air guide element to lower further relative to its lowered position, the downforce increases with speed. This eliminates the need for actuators such as electric, hydraulic, or pneumatic actuators, particularly for lowering the air guide element, or at least a portion thereof, from its lowered position.At high cornering speeds or during high lateral accelerations, the increased downforce on the front axle enhances the vehicle's directional stability. The driver thus benefits from particularly precise steering feel and agile handling. Furthermore, the raised position ensures superior everyday usability.

[0020] In order to be able to lower at least the partial area of ​​the air guide element particularly effectively with increasing driving speed, in one embodiment of the invention it is provided that the airfoil profile is partially formed by the part of the air guide element made of the elastically deformable material.

[0021] In a preferred embodiment, the air guide element and / or the splitter are made of a non-rubber-elastic material. In a further, particularly advantageous embodiment of the invention, the material is a fiber-reinforced plastic, in particular a carbon fiber-reinforced plastic. This allows the weight of the air guide element to be kept particularly low while simultaneously achieving particularly high stiffness, thus enabling particularly efficient airflow. This results in exceptionally high aerodynamic efficiency.

[0022] Another embodiment is characterized in that the part of the air guide device formed from the elastically deformable material is at least partially an integral part of the section of the air guide element that is movable between the raised and lowered positions. The elastic part can, for example, be injection-molded onto the air guide element and, optionally, also onto the splitter. This allows the air flowing towards and around the air guide element to flow particularly advantageously, and especially directly, towards and around the elastic part, so that it is effectively elastically deformed and, consequently, at least the section is advantageously lowered, particularly without the use of a separate, additional actuator.

[0023] A second aspect of the invention relates to a passenger car with an air guidance device according to the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0024] Further advantages and details of the invention will become apparent from the following description and the accompanying drawing. These show: Fig. 1 shows a partial schematic and perspective front view of a passenger car, at the front of which an air guide device is arranged, comprising an air guide element with at least one part made of an elastically deformable material; Fig. 2 shows a partial schematic side view of the passenger car; Fig. 3 shows a partial further schematic and perspective front view of the passenger car; Fig. 4 shows a partial further schematic side view of the passenger car; Fig. 5 shows partial schematic and sectioned side views of the air guide device; Fig. 6 shows partial further schematic and sectioned side views of the air guide device; and Fig. 7 shows a partial further schematic and sectioned side view of the air guide device.

[0025] In the figures, identical or functionally equivalent elements are provided with the same reference symbols, so that reference is made to the description of the preceding figures.

[0026] Figure 1Figure 1 shows a partial schematic and perspective front view of a passenger car 10, at the front 12 of which an air guide device 14 is arranged. The air guide device 14 includes, for example, a so-called splitter 16, which is an aerodynamic device used, among other things, to increase the downforce at the front of the vehicle. When the passenger car is traveling forward, the airflow approaching the front of the vehicle is split, with one portion directed upwards and used, for example, to cool components or assemblies, while another portion is directed under the passenger car.Since the air guide device 14 or the splitter 16 has a corresponding profile, preferably an inverted airfoil or a profile that at least approximates an inverted airfoil in its function, the air directed under the splitter 14 is accelerated as it flows under the passenger car. This creates a low pressure and thus downforce on the front axle.

[0027] The splitter 16 is preferably plate-shaped, with this plate running horizontally or substantially horizontally, and extends at least over a partial area of ​​the passenger car in the transverse direction of the vehicle (y-direction in the vehicle coordinate system). Furthermore, the air guide device 14 has a rounded or substantially rounded leading edge 17.

[0028] In conjunction with Figure 2It can be seen that the passenger car 10 has a front bumper cover 18 at its front 12, which, for example, extends upwards in the vehicle's vertical direction to the air guide device 14 and / or the splitter 16. By means of the bumper cover 18, a front cross member of the passenger car 10, not visible in the figures, is covered and thus concealed in the longitudinal direction of the vehicle and, if applicable, on both sides in the transverse direction.

[0029] The passenger car 10 further comprises an area at its front 12 designed as an engine compartment, in which a drive motor, for example an internal combustion engine, is arranged for propelling the passenger car 10. At least a portion of the engine compartment is overlapped in the longitudinal direction of the vehicle towards the front by a grille 20, also referred to as a radiator grille, through which air can flow, for example, when the passenger car 10 is traveling forward. The air flowing longitudinally from front to rear through the grille 20 enters the engine compartment and can, for example, flow towards and around a radiator located in the engine compartment. The radiator and the drive motor are, for example, components or parts of the passenger car 10 located in the engine compartment.

[0030] Especially good in conjunction with the Figures 5 to 7It is evident that the air guide device 14, in addition to the splitter 16, also includes at least one air guide element 22. For example, at least a portion of the engine compartment in the vehicle's vertical direction is overlapped and thus covered by the air guide element 22 downwards, so that the air guide element 22 can be a trim component. Alternatively or additionally, at least a portion of at least one of the components in the vehicle's vertical direction (z-direction in the automotive coordinate system) can be covered and thus covered by the air guide element 22 downwards. In particular, it is conceivable that the air guide element 22 is a component of the splitter 16.

[0031] As from the Figures 1 to 5As can be seen, the air guide element 22 can be moved at least in a partial area, in particular at least predominantly or completely, between a raised position S1, which is also referred to as the retracted position, and a lowered position S2, which is also referred to as the extended position, at least in the vehicle's vertical direction and in the present case also in the vehicle's longitudinal direction (x-direction in the motor vehicle coordinate system), in particular relative to the aforementioned components and preferably relative to the self-supporting body of the passenger car 10.

[0032] As in Figure 4As illustrated by arrows 24 and 25, to move the air guide element 22 from the raised position S1 to the lowered position S2, the entire air guide assembly 14, i.e., in particular the unit / combination comprising the splitter 16, the elastic part T1, and the air guide element 22, is first moved forward in the longitudinal direction of the vehicle – following the direction of arrow 24 – and, after reaching the extended position, the air guide element 22 is moved downward in the vertical direction of the vehicle – following the direction of arrow 25 – particularly relative to the respective component. To move the air guide element 22 from the lowered position S2 to the raised position S1, the air guide element 22 is moved upward in the vertical direction of the vehicle and backward in the longitudinal direction of the vehicle relative to the respective component and, in particular, relative to the body shell.

[0033] How particularly good looks Figure 5As can be seen, the air guide element 22, at least in the lowered position S2, together with the splitter 16 and a further part T1, which will be discussed in more detail below, forms an airfoil profile T, by means of which, in the case of a longitudinal movement from front to rear in the direction of the vehicle, Figure 5 The airflow around the airfoil T, illustrated by arrow 26, is a downward-acting flow in the upward direction of the vehicle and in Figure 5 The downward force can be generated by a force arrow F.

[0034] As is well known from the general state of the art, aircraft wings, and thus airfoils, generate a vertically upward lifting force when air flows from front to back around the airfoils, thus enabling the aircraft to fly. Compared to such an aircraft airfoil, the airfoil T of the air guide device 14 is an inverted or upside-down airfoil, since the airfoil T then, when in Figure 5 The air, illustrated by arrow 26, flows from front to rear around the airfoil T in the longitudinal direction of the vehicle, generating a downward force acting in the upward direction of the vehicle and thus creating downforce. For example, when the passenger car 10 travels along a roadway 28, also referred to as the ground ( Figure 5) is driven forwards, sucked or pushed against the roadway 28.

[0035] The air guide device 14 or the air guide element 22 has at least part T1, which is made of an elastically or rubber-elastically deformable material, in particular rubber or an elastomer, and is thus elastically or rubber-elastically deformable. Part T1 is, for example, designed as a lip, in particular a rubber lip, and forms a connecting element between the air guide element 22 and the splitter 16. For this purpose, part T1 is attached at one end to the splitter 16, preferably in the region of its leading edge 17, in particular below it and offset to the rear in the longitudinal direction of the vehicle, and at the other end to the front transverse edge region of the air guide element 22.The air guide element 22 is pivotably mounted at its rear edge about an axis, which preferably runs in the transverse direction of the vehicle, so that the air guide element 22 can be lowered or raised again at its front edge, where the part T1 is held. Together with the pivotable mounting about the axis, this results in the air guide element 22 being tilted and angled.Starting from the lowered position S2, part T1 is increasingly elastic or rubber-elastic deformable with increasing speed of the flow, i.e., with increasing relative speed between the flow illustrated by arrow 26 and the airfoil T, which makes it possible to lower at least part of the air guide element 22 or the air guide element 22 itself from the extended position S2 downwards in the vehicle's upward direction, by pivoting the air guide element 22 around the pivot bearing at its rear end so that its front edge area approaches the ground, for example a road surface.In other words, if the driving speed at which the passenger car 10 is driven forward along the roadway 28, while the air guide element 22 is initially in the lowered position S2, is increased, the relative speed between the airfoil T and the airflow around the airfoil T in the longitudinal direction of the vehicle from front to rear increases. Figure 5The air is illustrated by arrow 26. This also increases, for example, a force acting on the air guide element 22, which is initially in the lowered position S2 and is directed downwards in the upward direction of the vehicle, such as the downforce, so that the part T1 is increasingly elastically deformed with increasing driving speed or with increasing force, such that the air guide element 22 or at least its part is lowered further downwards in the upward direction of the vehicle from the lowered position S2.In order for part T1 to deform elastically in the manner described above, thus enabling the air guide element 22 to lower or be lowered further relative to the splitter 16, the splitter 16 is designed to be correspondingly robust and preferably remains in its position, being pulled downwards by the air guide element 22 and part T1 only to a very small extent, or not at all. The splitter 16 therefore withstands the forces causing the deformation of part T1 and is deformed or bent downwards only to a negligible degree, if at all.

[0036] The entire air guidance system 14, comprising the splitter 16, the part T1 and the air guidance element 22 pivotably mounted at its rear end, is mounted on the passenger car as a unit displaceable in the longitudinal direction of the vehicle in the horizontal direction and from a position pushed back into the front of the vehicle, which in Figure 2is shown in an extended position projecting forward over the bow or the front of the vehicle, as shown in Figure 4 As depicted, it will be relocated. In its retracted position according to Figure 2 The air guide device 14, in particular the air guide element 22, is held by means of a locking device (not shown in the figures) such that it cannot tilt downwards at its front end or lower due to deformation of part T1. In the retracted position, practically only the splitter 16 is effective and fulfills its original function, while the air guide element 22, in its raised position, has no or practically no diffuser function; that is, it does not yet narrow the space below the splitter 16 and the roadway. To now move the air guide device 14 from its retracted position ( Figure 2 ) into their forward-extended position ( Figure 4To be able to reposition the air guide assembly 14, the locking mechanism must first be released so that the entire assembly can be moved. Part T1 is dimensioned so large, or has an excess of material, that when the air guide assembly 14 is extended, the air guide element 22 pivots about its bearing axis and is thus lowered at the front until the elastic part T1 is under tension to a certain extent. This tilting preferably occurs automatically due to the force of gravity acting on the air guide element 22.

[0037] The function of the air guide device 14, in particular that of the elastic part T1, is described below using the Figure 5 explained in more detail. The air guidance device 14 is shown in a highly schematic form already in its extended position according to Figure 4 shown in the left illustration of the Figure 5Figure 1 shows a first state Z1 of the air guide device 14. In state Z1, for example, the passenger car 10 is stationary on the roadway 28, or the passenger car 10 is moving forward along the roadway 28 at a low speed, so that the air guide element 22 is in the lowered position S2. In the middle figure of the Figure 5Furthermore, a second state of the air guide device 14 is designated Z2. In the second state Z2, the passenger car 10 is driven forward along the roadway 28 at a higher speed than in state Z1. In state Z2, the speed of the passenger car 10 is so high that the part T1 is elastically deformed by the airflow compared to state Z1, such that the air guide element 22 is lowered further downwards in the upward direction of the vehicle compared to state Z1 and thus compared to the lowered position S2, thereby assuming a third position S3. It should be noted again that the lowering is achieved by pivoting the air guide element 22 around its axis at its end region facing away from part T1, so that the air guide element 22 tilts downwards at the front.In the third position S3, at least the section of the air guide element 22 is positioned further down in the upward direction of the vehicle than in the lowered position S2. Furthermore, the right-hand illustration shows the... Figure 5 Z3 designates a third state of the air guide device 14. In the third state Z3, the passenger car 10 is driven forward along the roadway 28 at an even higher speed than in the second state Z2. Consequently, in the third state Z3, part T1 is elastically deformed to a greater extent than in the second state Z2, so that in the third state Z3, the air guide element 22 is further lowered in the vehicle's upward direction. Thus, in the third state Z3, the air guide element 22 assumes a fourth position S4, in which the air guide element 22 is positioned further downwards in the vehicle's upward direction compared to the third state Z3 or the third position S3.

[0038] The further lowering of the air guide element 22 from the lowered position S2 to the position S3 or S4 is carried out solely by increasing the driving speed of the passenger car 10 or solely by increasing the relative speed between the airfoil T and the airflow and thus without the use of additional, active actuators.

[0039] The air guide element 22 and in particular its movement or mobility between positions S1, S2, S3 and S4 is also particularly well suited to Figure 7 This is evident from the arrow 29, which illustrates that the air guide element 22, or at least a portion thereof, can be pivoted about a pivot axis relative to the respective previously mentioned component or relative to the self-supporting body between positions S1-4. Furthermore, it is evident from Figure 7It is evident that part T1 is at least partially, and in particular at least predominantly or completely, a component of the airfoil T, such that the airfoil T is partially formed by part T1. The air guide element 22 forms at least one second part T2 of the airfoil T, which extends rearward in the longitudinal direction of the vehicle and adjoins the first part T1, formed from the elastically deformable material. The air guide element 22 adjoins part T1 directly in the longitudinal direction of the vehicle, with both part T1 itself and the air guide element 22 preferably being formed in one piece. The air guide element 22 is made of a non-rubber-elastic material. In the embodiment shown in the figures, the material is a carbon fiber-reinforced plastic, so that a particularly high stiffness of the air guide element 22 can be achieved in a particularly weight-efficient manner.This allows the air, which initially flows towards and around part T1 and then from part T1 to the air guide element 22, to be advantageously guided by the air guide element 22 without excessive deformation of the air guide element 22. The airfoil T is also partially formed by the second part T2, i.e., the air guide element 22. This means that the air guide element 22 is at least partially, and in particular at least predominantly or completely, a component of the airfoil T.

[0040] In Figure 7 The air guide device 14 and the air guide element 22 are each shown in different positions. The function of the air guide device 14 is explained in more detail below. The air guide device 14 is shown in the illustration according to Figure 7 shown in its retracted position at the top right, in which the leading edge 17 of the splitter 16 is in a rear position, as also in Figure 2The air guide element 22 is shown in a raised position – here approximately parallel to a roadway. The air guide device 14 is then moved forward in the direction of arrow 24 in the forward direction of travel, and the locking mechanism of the air guide element 22 is released before or during this movement, so that it is in the extended position of the splitter 16, as shown in the figure. Figure 4As shown, the air guide element 22 can tilt downwards at the front, which is made possible by the pivot bearing (not shown) at its rear end in the direction of arrow 29. This shifts the air guide element 22 into position S2. At sufficiently high driving speeds, the air guide element 22 can lower further into positions S3 and S4, which is made possible by the elastic part T1. If the wind load acting on the air guide element decreases, the elastic part T1 contracts again, so that the air guide element 22 shifts back from position S4 to S3 and then to S2, pivoting around the bearing axis in the opposite direction to arrow 29 and lifting in the process. The lowering of the air guide element 22 in the area of ​​its front edge narrows the space under the vehicle, allowing the air to flow freely and also imposing a direction on the airflow.This is how the so-called "Venturi effect" occurs in a moving motor vehicle, meaning that the air flows faster when it is constricted.

[0041] Out of Figure 6 The so-called touchdown management of the air guidance device 14 is particularly evident. As in Figure 6As shown particularly schematically and designated K, a collision of the air guide element 22 with the ground or an object located on the ground, such as a curb, stone, object, or the like, can occur, especially when the air guide element 22 is in position S2, S3, or S4. For example, the air guide element 22 is a shell, also referred to as a lower shell. Since the air guide element 22 is made, for example, of carbon fiber reinforced plastic, it is also referred to as a carbon shell or carbon lower shell. Because part T1 is elastically deformable, the air guide element 22 can deflect upwards in the vehicle's vertical direction in the event of a collision K with the roadway 28 or with an object located on the roadway 28 by pivoting upwards about its bearing axis.After the collision K has ended, the elastically deformed part T1 can at least partially relax and thus spring back, so that the air guide element 22 returns to its original position, which it had assumed before the collision K. Excessive damage to the air guide device 14 can thus be avoided.

[0042] Part T1 is increasingly elastically deformed with increasing driving speed, particularly because the negative pressure acting on the airfoil T, or on part T1, increases with increasing driving speed or relative speed between the airflow and the airfoil T, especially between the road surface 28 and the air guide 14. With increasing elastic deformation of part T1, the air guide 22 is increasingly lowered in the upward direction of the vehicle, further increasing the downforce. This increase in downforce, starting from position S2, is achieved solely by the increasing negative pressure and thus without an active actuator.By lowering or extending the air guide element 22, the air resistance of the passenger car 10 is also reduced, so that a particularly high aero-efficiency of the passenger car 10 can be achieved by means of the air guide device 14.

Claims

1. Air guide (14) for the front (12) of a passenger car (10), comprising at least one air guide element (22) which, at least in a partial region, at least in a vehicle vertical direction, is movable between a raised position (S1) and a lowered position (S2), the air guide (14) having a splitter (16), the splitter (16) and the air guide element (22) being connected by means of at least one part (T1) formed from an elastically deformable material, which part is increasingly elastically deformable with increasing speed of the flow (26), and, in the lowered position (S2), the air guide element (22) forming at least one part of an airfoil (T) by means of which a downforce (F) which is downwardly acting in the vehicle vertical direction can be generated when there is a flow (26) of air around the airfoil (T) in the vehicle longitudinal direction from front to rear, characterized in that the splitter (16), the elastic part (T1) and the air guide element (22) are mountable on the passenger car in a horizontal direction so as to be movable as one unit in the car longitudinal direction, and are movable together between a position that is retracted into the front of the car and a position that is extended forward.

2. Air guide (14) according to claim 1, characterized in that the airfoil (T) is formed partly by the part (T1) and, if applicable, partly by the splitter (16).

3. Air guide (14) according to claim 1 or claim 2, characterized in that the air guide element (22) and / or the splitter (16) are / is formed from a non-rubber-elastically deformable material.

4. Air guide (14) according to any of the preceding claims, characterized in that the part (T1) is formed elastically such that, with increasing speed of the flow (26) from the air guide (14), a further lowering at least of a partial region of the air guide element (22) downward in the vehicle vertical direction is effectible starting from the lowered position (S2).

5. Air guide (14) according to any of the preceding claims, characterized in that the part (T1) is folded at least in portions when the air guide element (22) is in the raised position (S1).

6. Air guide (14) according to any of the preceding claims, characterized in that, in its raised position (S1), the air guide element (22) is fixable in its relative position with respect to the splitter (16).

7. Air guide (14) according to any of the preceding claims, characterized in that the air guide element (22) is pivotably mounted at its rear transverse edge region, the position of the pivot axis in the vehicle vertical direction being consistent in every position of the air guide (14).

8. Air guide (14) according to any of the preceding claims, characterized in that the air guide element (22) is tabular.

9. Passenger car comprising an air guide (14) according to any of the preceding claims.