Air guidance system for a passenger car and passenger cars

Abstract

The invention relates to an air guide device (14) for the front (12) of a passenger car (10), comprising at least one air guide element (16), and an adjustment device (22) by means of which the air guide element (16) is adjustable between two states (Z1, Z2). In a first of the states (Z1, Z2), the air guide element (16) forms a first airfoil profile (P1) whose chord line (S1) has a first length (L1). In a second of the states (Z1, Z2), the air guide element (16) forms a second airfoil profile (P2) whose chord line (S2) has a second length (L2) that is greater than the first length (L1).

Description

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

[0002] DE 10 2020 006 694 A1 discloses an air guidance device for the front of a passenger car, with at least one air guidance element which is movable at least in a partial area, at least in the upward direction of the vehicle, between a raised position and a lowered position.

[0003] DE 10 2020 132 902 B3 discloses an air guidance device at the front of a vehicle, which comprises a fixed, first air guidance element and second and third air guidance elements arranged behind it in the direction of airflow, which can be pivoted into different positions by means of a respective adjustment device.

[0004] Furthermore, DE 10 2014 111 074 A1 discloses an airflow guidance device which is arranged in the lower front area of ​​a motor vehicle and comprises a horizontally movable airflow guidance element in the longitudinal direction of the vehicle, which is assigned to a second airflow guidance element to improve the flow effect in the front area of ​​the motor vehicle.

[0005] From DE 36 25 814 A1, a motor vehicle is known in which, to achieve good road grip, the vehicle floor in the rear area is designed to rise towards the rear of the vehicle, and an air guide vane is arranged in the space below the rising rear floor, on which downforce is generated when air flows from the front of the vehicle. The air guide vane is arranged such that its underside is at least as far from the road surface as the vehicle floor at its lowest point in front of the rear of the vehicle.

[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 advantageous variability of the air guidance device can be realized.

[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 10. 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, also referred to as a motor vehicle or vehicle, has the air guide device at its front in its fully manufactured state. 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 passenger car. This area is, for example, an area of ​​the engine compartment in which a drive motor, in particular an internal combustion engine, can be arranged for propelling the passenger car.In particular, the engine compartment is at least partially, and especially at least predominantly and thus to more than half, covered and thus completely by the air guide element in the vertical direction of the vehicle. Alternatively or additionally, at least one component of the passenger car, especially 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 covered by the air guide element in the vertical direction of the vehicle. The component is, for example, a support element, especially a longitudinal member. The support element can be part of a 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 passenger car.

[0009] In order to achieve a particularly advantageous, and especially a particularly needs-based, variability of the air guide device, and in particular of its aerodynamic behavior, an adjustment device is provided according to the invention by means of which the air guide element can be adjusted between, in particular at least or exactly, two states. In a first of the states, the air guide element forms a first airfoil profile, the chord line of which, also referred to as the first chord line, has a first length. In a second of the states, the air guide element forms a second airfoil profile, the chord line of which, also referred to as the second chord line, has a second length that is greater than the first length.As is well known from the general state of the art of conventional airfoil profiles, the respective airfoil profile, also referred to as a wing profile, formed in the respective state by the air guide element, accelerates the air in the longitudinal direction of the passenger car from front to rear when air flows around the respective airfoil profile, that is, when air flows around the respective airfoil profile in the longitudinal direction of the vehicle from front to rear, in particular such that the air flowing around the respective airfoil profile flows faster on one of the first sides than on the second side, with respect to two sides of the respective airfoil profile opposite each other in the vertical direction of the vehicle.

[0010] In particular, the adjustment device can effect a change in the external shape of the air guide element, also referred to as a shape change, such that the air guide element has a first external shape in the first state and a second external shape in the second state that differs from the first. The shapes differ at least or exclusively in that the chord line of the second airfoil is longer than the chord line of the first airfoil. Thus, the adjustment device can be used to selectively adjust either the first airfoil with the chord line of the first length or the second airfoil with the chord line of the second length, thereby allowing the aerodynamic behavior of the air guide element, and consequently of the passenger vehicle as a whole, to be varied, i.e., adjusted, as required.In particular, for example, a driver of the passenger car can adjust the air guide element between states as required and thus adjust the aerodynamic behavior of the air guide element and thus of the passenger car as a whole as required, in particular by, for example, the driver of the passenger car operating a control element located in the interior of the passenger car, in particular manually.

[0011] The adjusting device is designed, for example, to selectively introduce a fluid, such as a gas or a liquid, into the air guide element, i.e., into the interior of the air guide element, in particular to pump it in, or to pump it out of the air guide element, i.e., out of the interior, or to allow the fluid to be discharged or flow out of the air guide element in order to adjust the air guide element between states. For example, to adjust the air guide element from the first state to the second state, the adjusting device pumps the fluid into the air guide element, i.e., into its interior.To adjust the air guide element from the second state to the first state, for example, the fluid is pumped out of the air guide element, i.e., from its interior, and / or the fluid is allowed to flow out of the air guide element, i.e., from its interior, by means of the adjusting device. Alternatively or additionally, it would be conceivable that the adjusting device has at least one adjusting element designed as a solid body, such as a lever, wherein the air guide element can be adjusted between the states, for example, by moving the adjusting element, particularly relative to a shell of the air guide element. The adjusting device may, for example, have an electrically operated actuator by means of which the adjusting element can be driven and thus moved, particularly relative to the shell.In particular, it is conceivable that the adjusting element is arranged in the air guide element, that is, inside it.

[0012] To create a particularly advantageous variability of the air guide device and thus to be able to vary the aerodynamic behavior of the passenger car to a particularly advantageous degree, one embodiment of the invention provides that the adjustment device is designed to adjust the air guide element between states, while a bearing change in the vertical direction of the vehicle of at least a predominant part of the air guide element, i.e., a bearing change of at least more than half of the air guide element, particularly with regard to a volume of the air guide element, is prevented. This allows the aerodynamic behavior of the passenger car to be influenced, in particular solely, by varying the length of the profile chord, without a vertical displacement of the entire air guide element in the vertical direction of the passenger car.

[0013] As is well known from the general prior art, the airfoil chord is a technical term from fluid mechanics and airfoil design. The airfoil chord is understood to be an imaginary, straight line connecting the leading edge of the airfoil to the trailing edge. In the context of the present invention, the leading edge of the airfoil is, or in the respective state, the foremost point of the airfoil in the longitudinal direction of the passenger car. Conversely, the trailing edge of the airfoil is, or in the respective state, the rearmost point of the airfoil in the longitudinal direction of the vehicle.

[0014] It has proven particularly advantageous if the adjustment device is designed to adjust the air guide element between states such that the foremost point, i.e., the profile nose, is movable relative to the rearmost point, i.e., relative to the profile trailing edge, particularly translationally and / or in the longitudinal direction of the vehicle and / or translationally, especially while movement of the rearmost point is prevented. In other words, it is preferably provided that, for adjusting the air guide element between states, the profile nose is movable by means of the adjustment device, particularly in the longitudinal direction of the vehicle and / or translationally and / or along an axis of movement, relative to the profile trailing edge and relative to a base element of the air guide device, particularly while movement of the profile trailing edge relative to the base element is prevented.This allows for particularly advantageous variability of the air guidance system, enabling highly beneficial adjustments to the aerodynamic behavior of both the air guidance system and the passenger power plant. This applies, for example, to the base element and the aforementioned component. For instance, the axis of movement is straight. In other words, the axis of movement is a straight line. For example, the axis of movement runs parallel to the longitudinal direction of the vehicle.

[0015] In order to achieve a particularly advantageous aerodynamic behavior of the passenger power plant, it is further provided in the invention that, at least in the second state, the foremost point of the air guide element is the foremost point of the passenger car when viewed in the longitudinal direction of the vehicle.

[0016] In a further, particularly advantageous embodiment of the invention, it is provided that both the first airfoil profile and the second airfoil profile are designed to generate a downward downforce acting in the upward direction of the vehicle when air flows around the respective airfoil profile from front to rear in the longitudinal direction of the passenger car.This means that, according to the invention, the respective airfoil profile is preferably an inverted, i.e., upside-down, airfoil profile compared to aircraft, whose airfoils generate lift forces acting vertically upwards when air flows around them. When the respective airfoil profile according to the invention is exposed to air flow from front to back in the longitudinal direction of the vehicle, 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 causes the passenger car, when driven along a road, particularly forwards, to be pulled or pushed downwards in the upward direction of the vehicle and thus against the road surface.

[0017] Since the second length is greater than the first length—that is, since the chord line of the second airfoil is longer than the chord line of the first airfoil—the downward downforce acting in the vehicle's vertical direction is greater in the second state than in the first. The second state is therefore suitable, for example, for achieving particularly advantageous lateral dynamic handling characteristics of the passenger car, allowing it to be driven safely through curves at high speeds. Thus, the second state is, for example, a racing or sports driving state in which the passenger car can be driven very sportily, especially through curves. The first state, on the other hand, is a road driving state in which the passenger car can be driven energy-efficiently, for example, on public roads.This allows the air guidance system to be varied particularly advantageously, especially to meet specific needs.

[0018] The invention is based in particular on the following findings and considerations: For passenger cars, especially those designed as high-performance vehicles, there can be a very large difference between the requirements for a contact pressure acting towards the roadway during normal road driving and the requirements for a contact pressure acting towards the roadway during racing on a race track.A very high downforce, and thus a very high downward force acting in the vehicle's vertical direction, is advantageous for safe cornering under high lateral accelerations, i.e., at high speeds. Conversely, during normal road driving, lower vertical aerodynamic loads, and therefore a lower downforce, are advantageous for achieving a low drag coefficient and thus particularly energy-efficient, and consequently fuel-efficient, operation of the passenger car. Thus, there is typically a conflict between achieving a high downward downforce acting in the vehicle's vertical direction and a correspondingly lower downforce. The invention resolves this conflict.The air guidance device according to the invention is an active, and therefore actively adjustable, air control system which allows either the first state or the second state to be set and thus optionally a favorable low drive force or a correspondingly favorable higher drive force to be realized.

[0019] Conventional solutions include horizontal, active blades mounted at the front, functioning as splitters or active front diffusers, but not as active wings. These blades can change their position vertically, depending on aerodynamic requirements, by selectively lowering or raising them. In contrast to such splitters or diffusers, the airfoil profile of the invention utilizes both sides, thereby increasing efficiency and downforce without incurring excessive drag.

[0020] The air guide element of the air guide device according to the invention is, in both states, a horizontal, active profile whose outer shape can be modified as needed to selectively form either the first airfoil profile or the second airfoil profile. A vehicle's front bumper cannot usually be designed to generate very high downforce on the one hand and simultaneously achieve the lowest possible air resistance on the other. The invention now offers the possibility of modifying the outer shape of the air guide element as needed, thereby enabling the passenger car to be driven both energy-efficiently, for example on public roads, and very sportily, for example on closed, private racetracks.

[0021] The adjustment device is, for example, an electric and / or pneumatic and / or hydraulic adjustment device by means of which the air guide element can be adjusted between states electrically, i.e., using electrical energy, and / or pneumatically and / or hydraulically. Furthermore, it would be conceivable that alternative or additional adjustment devices could be manually operated by a person to adjust the air guide element between states as needed. This would allow for a simpler and more lightweight design of the air guide device.

[0022] The air guide element of the air guide system is also referred to as the first air guide element. When the term "air guide element" is used previously and subsequently, it refers, unless otherwise specified, to the first air guide element.

[0023] In order to achieve particularly advantageous aerodynamics, and thus particularly advantageous aerodynamic behavior of the passenger car, a further embodiment of the invention provides that the air guide device has a second air guide element which extends rearward and upwards in the longitudinal direction of the vehicle to the first air guide element. Preferably, the air guide elements are, in particular, completely spaced apart from one another.

[0024] It has proven particularly advantageous if the second air guide element forms a third airfoil profile, whose chord line, for example, has a third length. For example, the third length is shorter than the second length. For example, the third length is shorter than the first length.

[0025] In order to enable the passenger car to be driven in a sporty and energy-efficient manner on the one hand, the invention further provides that the third airfoil profile is designed to generate a downforce acting in the vertical direction of the vehicle and / or in the longitudinal direction of the vehicle towards the rear when air flows around the third airfoil profile from front to rear.

[0026] A second aspect of the invention relates to a passenger car, also referred to simply as a vehicle, which has an air guidance device according to the first aspect of 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.

[0027] Further advantages and details of the invention will become apparent from the following description and the accompanying drawing. These show: Fig. 1. Partially a schematic and perspective front view of a passenger car, on the front of which an air guidance device is arranged, which has at least one air guidance element; Fig. 2. A schematic and cutaway side view of the passenger car, wherein the air guide element is in a first state; Fig. 3 a schematic and cutaway side view of the air guide element in the first state; Fig. 4. A schematic and cutaway side view of the passenger car, showing the air guide element in a second state, and Fig. 5 A schematic and cutaway side view of the air guide element in the second state.

[0028] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0029] Fig. Figure 1 shows a partial schematic and perspective front view of a passenger car 10, also referred to as a vehicle, whose front is labelled 12. An air guide device 14 of the passenger car 10 is arranged on the front 12. From a combination of Fig. Figures 1 to 5 show that the air guidance device 14 has a first air guidance element 16, which is surrounded by or with air when the passenger car 10 is traveling forward. In particular, forward travel is understood to mean straight-ahead travel of the passenger car 10 in the longitudinal direction of the vehicle. Fig. Arrows 18 and 20 illustrate the aforementioned air flowing around the air guide element 16 in the longitudinal direction of the passenger car 10 from front to rear during the aforementioned straight-ahead driving. In other words, arrows 18 and 20 illustrate an airflow around the air guide element 16 in the longitudinal direction of the passenger car 10 from front to rear. To achieve particularly advantageous variability of the air guide device 14 and thus particularly advantageous, demand-based variability of the aerodynamic behavior of the air guide device 14 and the passenger car 10 as a whole, the air guide device 14 has a Fig. 2. A particularly schematically illustrated adjustment device 22 is shown. By means of the adjustment device 22, the air guide element 16 is positioned between a Fig. 2 and Fig. 3 shown first state Z1 and one in Fig. 4 and Fig. The second state Z2 shown in Figure 5 is adjustable. In the first state Z1, the air guide element 16 forms a first airfoil profile P1, whose first chord line S1 has a first length L1. In the second state Z2, the air guide element 16 forms a second airfoil profile P2, whose second chord line S2 has a second length L2, which is greater than the first length L1. This is particularly evident from Fig. Paragraphs 2 to 5 show that the air guide element 16, in its respective state Z1, Z2, has a leading point 24 and a trailing point 26 when viewed in the longitudinal direction of the passenger car 10. The leading point 24 is, or forms, the leading edge of the respective airfoil profile P1, P2, and point 26 is, or forms, the trailing edge of the respective airfoil profile P1, P2. It is also evident that the respective chord line S1, S2 is an imaginary line running along an imaginary straight line from one of points 24, 26 to the other point 26, 24. The respective length L1, L2, is thus the distance along the respective imaginary straight line between the respective points 24 and 26.

[0030] In Fig. 1, Fig. 2, Fig. 4. Also recognizable is a front trim element 28 of the passenger car 10, whose front trim element 28 is, for example, a front bumper trim. Recognizable from Fig. 1, Fig. 2 and Fig. 4 is also a left front wheel 30 of the passenger car. The axis of rotation of the front wheel 30 is designated 32, and the direction of rotation of the front wheel 30 is illustrated by an arrow 34. During the aforementioned forward movement of the passenger car 10, the front wheel 30 rotates about the axis of rotation 32 in the direction of rotation illustrated by the arrow 34, in particular relative to the fairing element 28 and the air guide element 16.

[0031] The air guide element 16, and thus the respective airfoil P1, P2, has two sides SE1 and SE2 opposite each other in the vehicle's vertical direction. In the respective state Z1, Z2, side SE1 points upwards in the vehicle's vertical direction, and side SE2 points downwards in the vehicle's vertical direction. Thus, side SE1 is the upper surface, and side SE2 is the lower surface. Arrow 18 illustrates a portion of the air flowing around the air guide element 16, and thus the respective airfoil P1, P2, flowing along the lower surface. Arrow 20 illustrates a portion of the air flowing around the air guide element 16, and thus the respective airfoil P1, P2, flowing along the upper surface.

[0032] Both the first airfoil profile P1 and the second airfoil profile P2 are designed to generate a downward downforce acting in the vertical direction of the passenger car 10 when air flows around them from front to rear in the longitudinal direction of the vehicle, particularly as a result of the aforementioned forward travel. The respective airfoil profiles P1 and P2 are designed and arranged such that a low pressure is created on the underside, especially compared to the upper surface, during the respective airflow. This low pressure results in the downforce, effectively sucking or pressing the passenger car 10 against the road or road surface when traveling forward along a road or lane.

[0033] In Fig. 3 and Fig. Arrows 36 illustrate the negative pressure acting on the underside and thus the downward force. Fig. 3 and Fig. As shown in Figure 5, because the second length L2 is larger than the first length L1, at the same speed at which the passenger car 10 travels forward along the road, the negative pressure and thus the downforce in the second state Z2 is greater than in the first state Z1. Therefore, particularly advantageous lateral dynamic driving characteristics of the passenger car 10 can be achieved in the second state Z2. In the first state Z1, the air resistance of the passenger car 10 can be kept particularly low, so that the passenger car 10 can be driven in a particularly energy-efficient manner and thus with low fuel consumption. Fig. 2 and Fig. Figure 4 illustrates an arrow 38 in a forward direction of travel, in which the forward travel of the passenger car 10 takes place.

[0034] In the embodiment shown in the figure, the adjusting device 22 is configured to adjust the air guide element 16 between states Z1 and Z2, while preventing any change in position of at least a predominant part T of the air guide element 16 in the upward direction of the passenger car 10, and in particular relative to the trim element 28. In other words, part T does not move in the upward direction of the vehicle relative to the trim element 28 while the air guide element 16 is being adjusted between states Z1 and Z2.

[0035] As in Fig. 4 and Fig.As illustrated by an arrow 40 in the embodiment shown in the Fig. 5, the adjusting device 22 is also designed to adjust the air guide element 16 between states Z1 and Z2 such that the foremost point 24 is movable relative to the cladding element 28 and relative to the rearmost point 26, while a movement of point 26 relative to the cladding element 28 does not occur.

[0036] The air guide device 14 has a second air guide element 42 in addition to the air guide element 16, which is completely spaced apart from the air guide element 16. The air guide element 42 connects to the first air guide element 16 in the longitudinal direction of the vehicle, towards the rear and above. The air guide element 42 forms a third airfoil profile P3, by means of which, when air flows around the third airfoil profile P3 from front to rear in the longitudinal direction of the vehicle, as illustrated by arrows 18 and 20, a downforce acting upwards and / or backwards in the longitudinal direction of the vehicle can be generated or is generated. The airflow around the airfoil profile P3 also results, for example, from the forward movement of the passenger car 10 described above.This allows for a particularly advantageous aerodynamic behavior of the passenger car 10 to be achieved by means of a particularly advantageous aerodynamics of the passenger car 10.

Claims

[1] Air guidance device (14) for the front (12) of a passenger car (10), comprising at least one air guidance element (16), characterized by an adjusting device (22) by means of which the air guide element (16) can be adjusted between two states (Z1, Z2), namely: - a first state (Z1) in which the air guide element (16) forms a first airfoil profile (P1) whose chord line (S1) has a first length (L1); and - a second state (Z2) in which the air guide element (16) forms a second airfoil profile (P2) whose profile chord (S2) has a second length (L2) that is greater than the first length (L1). [2] Air guidance device (14) according to claim 1, characterized by, that the adjusting device (22) is designed to adjust the air guide element (16) between the states (Z1, Z2), while a change in position in the upward direction of the vehicle of at least a predominant part (T) of the air guide element (16) does not occur. [3] Air guidance device (14) according to claim 1 or 2, characterized by , that in the respective state (Z1, Z2) the respective profile chord (S1, S2) extends from a foremost point (24) of the air guide element (16) viewed in the longitudinal direction of the vehicle to a rearmost point (26) of the air guide element (16) viewed in the longitudinal direction of the vehicle. [4] Air guidance device (14) according to claim 3, characterized by , that the adjusting device (22) is designed to adjust the air guide element (16) between the states (Z1, Z2) such that the foremost point (24) is movable relative to the rearmost point (26). [5] Air guidance device (14) according to claim 3 or 4, characterized by, that at least in the second state (Z2) the foremost point (24) of the air guide element (16) is the foremost point of the passenger car (10) when viewed in the longitudinal direction of the vehicle. [6] Air guidance device (14) according to any one of the preceding claims, characterized by , that both the first airfoil (P1) and the second airfoil (P2) are designed to generate a downward downforce in the upward direction of the vehicle when air flows around the respective airfoil (P1, P2) from front to rear in the longitudinal direction of the vehicle. [7] Air guidance device (14) according to any one of the preceding claims, characterized by , that the air guidance device (14) has a second air guidance element (42) which connects to the first air guidance element (16) in the longitudinal direction of the vehicle towards the rear and top. [8] Air guidance device (14) according to claim 7, characterized by, that the second air guide element (42) forms a third airfoil profile (P3). [9] Air guidance device (14) according to claim 8, characterized by , that the third airfoil (P3) is designed to generate a downforce acting in the vertical direction of the vehicle and / or in the longitudinal direction of the vehicle towards the rear when air flows around the third airfoil (P3) from front to rear. [10] Passenger car (10) with an air guidance device (14) according to one of the preceding claims.

Images