Footwell ventilation system for a vehicle

Abstract

A ventilation device for ventilating a footwell of a vehicle, comprising a cover (1) for covering an upper side of the footwell and comprising an air duct guided along the cover (1) for guiding air to be blown out into the footwell, wherein the cover (1) has a first air outlet (3) for blowing the air vertically downwards into the footwell and a second air outlet (5) for blowing the air horizontally towards the knees and thighs of an occupant, wherein the second air outlet (5) is integrated into the cover (1) without any material projection from a flat underside of the cover (1), characterized in that the second air outlet (5) has a Coanda guide vane (7) sunk into the cover (1), wherein the Coanda guide vane (7) has a convexly curved shape along the flow of the air to be blown out,which runs convergently in the direction of flow towards a horizontal plane and the Coanda guide vane (7) is designed in one piece with the rest of the cover (1).

Description

[0001] The invention relates to a ventilation device for ventilating a footwell of a vehicle, as well as a vehicle with such a ventilation device.

[0002] A wide variety of ventilation systems for vehicle interiors are known in the state of the art. These include, for example, ventilation on the instrument panel or in the footwell.

[0003] DE 603 ​​04 906 T2 relates to an air conditioning system for a motor vehicle, comprising an air distribution device with a structure which forms a main line and a plurality of outlet lines which are connected to the main line and are to be connected to a plurality of outlets for the outflow of air into the passenger compartment of the motor vehicle, a Coanda effect distribution device which is mounted in the structure of the distribution device and is movable into a plurality of operating positions, each of which causes a deflection of the air flowing through the main line into a selected one of the outlet lines by the Coanda effect.The distribution device further comprises: a radiating mass arranged upstream of the main duct such that it is traversed by the air flow entering the main duct from an inlet duct of the distribution device in order to heat the air flow; a device that determines a change in the temperature of the air flow conveyed in the main duct, the device being controlled by the Coanda effect distribution device such that the temperature of the air flowing out of the distribution device is a function of the operating position of the Coanda effect distribution device.

[0004] DE 10 2021 105 387 A1 also relates to a motor vehicle with at least one vehicle seat located in a vehicle interior and an outer side of an instrument panel facing the vehicle interior, in which a first air outlet having a first air outlet opening is accommodated, wherein the outer side - viewed in a virtual vertical longitudinal plane and in the vertical direction of the motor vehicle - has a contour that is recessed below the first air outlet opening and projects above the first air outlet opening in the direction of the vehicle interior, and the section of the outer side adjacent to the first air outlet opening is inclined with respect to the first air outlet opening in the longitudinal plane of the outer side at at least a first angle of inclination and is configured to allow an air flow flowing out of the first air outlet opening to flow along the adjacent section by means of the Coanda effect.wherein, viewed in the vertical direction, at the end of the contour distally from the first air outlet opening, there is a second air outlet opening of a second air vent, which is configured to discharge a second air flow into the vehicle interior, which second air flow is selectively acted upon by the first air flow or not, wherein both the first air outlet opening and the second air outlet opening are located outside the field of vision of a vehicle occupant sitting in the vehicle interior.

[0005] DE 20 2020 106 590 U1 further relates to a ventilation device for a vehicle which utilizes a Coanda effect and is mounted in a panel in a vehicle to discharge air into the vehicle through an outlet formed in the panel, the ventilation device comprising: a duct housing having a hollow shape, in which an air inlet is formed in one end portion thereof and an air outlet is formed in the other end portion thereof; a trim element having one end portion connected to surround the other end portion of the duct housing and the other end portion connected to the panel and in which a communication hole for communicating with the outlet is formed;and an air guide member arranged in the trim member, pivoted to the duct housing so as to be vertically rotatable, and having a through hole through which the air outlet communicates with the communication hole, wherein, when an inner peripheral surface of the air guide member, an inner peripheral surface of the communication hole, and an inner peripheral surface of the outlet form a continuous curved surface due to rotation of the air guide member, air supplied from the air inlet is discharged into the vehicle through the outlet by pivoting in a direction in which the continuous curved surface is formed.

[0006] JP 2018172043 A also relates to an automotive air conditioning duct that blows air to the vehicle occupants. A vehicle air conditioning duct structure is provided such that it protrudes radially inward on the inner surface near the opening of the air conditioning duct, and the air flowing along the inner surface of the outlet portion is separated from the inner surface according to the blowing speed to change the blowing direction.

[0007] DE 10 2007 051 471 A1 describes a vehicle with a ventilation or air conditioning system having at least one air outlet located in an area below an instrument panel or in a lower area of ​​the instrument panel. The instrument panel has a panel in the knee or shin area of ​​the vehicle's front seats. The air outlet is oriented such that the air flowing out of the air outlet flows essentially along the panel into the knee or thigh area.

[0008] DE 198 54 537 A1 relates to a ventilation device for a vehicle passenger compartment equipped with a dashboard, comprising several air vents integrated into the dashboard. These vents are provided in pairs, each assigned to a front seat, for separate ventilation of the driver and passenger sides of the passenger compartment. At least two additional air vents are provided below the dashboard, at least one of which is assigned to each front seat. The additional air vents are designed so that the air flow emerging from them impacts the knee and shin area of ​​the front passengers.

[0009] Most of the ventilation systems known in the prior art for ventilating footwells feature multiple air outlets through which conditioned air flows essentially vertically downwards toward the feet. While this solution provides comfortable airflow to the feet, it often results in a ventilation deficit in the knee and thigh areas, which, if heated air is supplied, results in a heat deficit at the knee and thigh.

[0010] The object of the invention is to achieve uniform ventilation of feet, knees and thighs in the area of ​​a vehicle's footwell.

[0011] The invention is based on the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims.

[0012] A first aspect of the invention relates to a ventilation device for ventilating a footwell of a vehicle, comprising a cover for covering an upper side of the footwell and comprising an air duct guided along the cover for guiding air to be blown out into the footwell, wherein the cover has a first air outlet for blowing the air vertically downwards into the footwell and a second air outlet for blowing the air horizontally towards the knees and thighs of an occupant, wherein the second air outlet is integrated into the cover without any material protrusion from a flat underside of the cover.

[0013] The first air outlet is used to direct the air to be blown out vertically downwards into the footwell towards the floor. An opening in the cover is sufficient for this, although the flow direction can optionally be guided specifically using air deflectors and directed towards the floor. The second air outlet, on the other hand, is used to direct the air to be blown out horizontally, perpendicular to the outlet direction of the first air outlet. This air, which flows horizontally after blowing out, flows towards the knees and thighs of the occupant, whose feet are in the footwell, into which the air flowing out of the first air outlet is directed downwards. The horizontal flow of the blown out air initially flows below the dashboard towards the shins - in the case of a footwell in front of a driver's seat - and rises along the thighs in the case of warm air.This not only warms the feet by the air flow from the first air outlet, but also the legs in the knee and thigh areas. If enough warm air is blown out, it flows upwards past the thighs near the upper body. This creates favorable ventilation close to the body, which, especially in cases where, for example, only the driver's seat needs to be air-conditioned, can save air conditioning energy, especially heating energy, and increase the electric range of electric vehicles. This leads to improved thermal comfort in the upper and lower leg areas, as well as the aforementioned efficiency improvement through close-to-body ventilation – this advantage is particularly evident when only a single occupant needs to be supplied with appropriately heated / cooled ventilation air.

[0014] Furthermore, it is intended that the second air outlet is integrated into the cover in such a way that no physical components (apart from any air guiding elements of the first air outlet) protrude downwards from the underside of the cover, such as a flow-diverting manifold to convert the air guided from the air duct of the cover into a horizontal flow on the underside of the cover.

[0015] The fact that the second air outlet is integrated into the cover in such a way that there is no material projection above a plane of the underside of the cover means, in particular, that there is no projection in the area of ​​the second air outlet; rather, the opening of the second air outlet is a recess in the underside of the cover, without any flow-deflecting elements intended to generate a horizontal flow directly in the flow direction behind the second air outlet below the underside of the cover. Rather, through clever aerodynamic shaping of air-guiding elements inside the cover in the area of ​​the second air outlet, the air flowing out there is guided in such a way that it flows horizontally when flowing out of the second air outlet.

[0016] The additional horizontal air flow from a second air outlet according to the invention, without an air outlet protruding downward from the cover and horizontal at its end, advantageously generates a horizontal air flow without requiring additional installation space in the footwell, i.e., without having to arrange additional components facing the footwell. To achieve the horizontal air flow after leaving the second air outlet, the Coanda effect is preferably utilized. The Coanda effect describes the phenomenon that a flowing fluid tends to follow a curved surface that is subjected to tangential flow.Thus, a fluid flow such as the air flow of the air to be blown out can be redirected and instead of an air flow otherwise directed downwards towards the floor of the footwell (as also occurs at the unmodified first air outlet), a horizontal air flow can be achieved behind an opening of the second air outlet.

[0017] According to an embodiment of the invention, the second air outlet has a Coanda guide vane sunk into the cover, wherein the Coanda guide vane has a convexly curved shape along the flow of the air to be blown out, which converges in the flow direction towards a horizontal plane.

[0018] According to an embodiment of the invention, the Coanda guide vane is designed as a single piece with the remaining cover.

[0019] The purpose of the Coanda guide vane is to convert the air flowing past the Coanda guide vane, which is released from the cover through the second air outlet, into a horizontal flow behind the second air outlet. While the air flow in the air duct along the cover is already horizontal in principle, this horizontal flow could not be directly converted into a horizontal flow after leaving the cover; rather, as in the case of the first air outlet, it would flow downwards towards the floor in the footwell. However, by using the Coanda guide vane in the second air outlet, the air flowing through the second air outlet follows the curvature of the Coanda guide vane, which converges at its end to a horizontal plane parallel to the floor of the footwell, i.e. in the flow direction of the air to be blown out, the end of the Coanda guide vane has (at least essentially) a horizontal tangent.The Coanda guide vane therefore begins within the cover and, thanks to its convex curvature facing the flow, guides the flowing air from the cover's air duct through the plane of the cover's underside. Following the curvature, the air assumes a horizontal flow at the end of the Coanda guide vane, since the end of the Coanda guide vane is also horizontal. The Coanda guide vane can extend across the entire width of the cover, and the cover can advantageously have bulges in the area of ​​the respective second air outlet. Multi-part Coanda guide vanes are also conceivable, which are arranged only in the area of ​​the respective second air outlet.

[0020] According to a further advantageous embodiment, the cover has at least two first air outlets in a first row and at least two second air outlets in a second row, wherein the first row and the second row run parallel to each other along a transverse axis of the vehicle.

[0021] The vehicle's transverse axis is typically perpendicular to a main direction of travel and runs in a fixed manner, for example, from a left wheel to a right wheel (or in the opposite direction) on the same axis. By arranging the first air outlets and the second air outlets in their own designated rows, each running along this vehicle's transverse axis or parallel thereto, aerodynamic interactions between the two types of air outlets can advantageously be avoided. Therefore, the row with the second air outlets is also advantageously arranged towards the vehicle seat, while the row with the first air outlets is preferably arranged towards the front of the vehicle. The horizontal outflow of air from the second air outlets can then flow unhindered, at least initially in a horizontal direction, without being disturbed by the downdraft from the first air outlets and without being deflected downwards towards the ground.

[0022] According to a further advantageous embodiment, the at least two first air outlets and the at least two second air outlets are each arranged offset from one another, so that the at least two first air outlets and the at least two second air outlets are arranged in a checkerboard pattern with respect to one another.

[0023] According to a further advantageous embodiment, the air duct is arranged between the cover and an upper shell arranged on the cover. The upper shell is arranged on the side of the cover facing away from the footwell.

[0024] Preferably, the cover is shaped by additive layer manufacturing or injection molding from plastic to enable the spatial structures, such as those of a Coanda guide vane, to be reproduced in one piece, and has corresponding recesses for the air duct. According to this embodiment, the air duct is then covered by the upper shell. Further aerodynamically functional shapes can be incorporated into this upper shell, such as concave bulges facing the flowing air, in order to achieve desired pressure conditions in the air flow, particularly immediately before or at the beginning of the air flow to the Coanda guide vane.

[0025] According to a further advantageous embodiment, the cover has a respective bulge in the region of a respective second air outlet, which bulges away from the footwell.

[0026] According to a further advantageous embodiment, the respective bulge forms a concave cavity in the area of ​​the flow of the air to be blown out, wherein the convex cavity serves as a flow guide.

[0027] According to a further advantageous embodiment, respective air guiding elements for guiding the blown-out air are arranged at the respective first air outlet and / or at the respective second air outlet.

[0028] The air guiding elements can in particular prevent an unwanted widening of the air jet at the first air outlet and / or at the second air outlet, which would also be accompanied by a reduction in the speed of the air jet and would thus hinder the targeted ventilation of the feet or legs of the occupant in the footwell.

[0029] A further aspect of the invention relates to a vehicle with a ventilation device as described above and below.

[0030] Advantages and preferred developments of the proposed vehicle result from an analogous and analogous transfer of the statements made above in connection with the proposed ventilation device.

[0031] Further advantages, features, and details will become apparent from the following description, which – where appropriate with reference to the drawings – describes at least one embodiment in detail. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0032] They show: Fig. 1: A vehicle interior with a ventilation device according to an embodiment of the invention. Fig. 2: A ventilation device in elevation with the cover plate from above according to an embodiment of the invention. Fig. 3: A ventilation device in elevation with the cover plate from below according to an embodiment of the invention. Fig. 4: A bulge of the cover with a Coanda guide vane according to an embodiment of the invention.

[0033] The representations in the figures are schematic and not to scale.

[0034] Fig. 1 shows a vehicle interior of a passenger car with a ventilation device for ventilating the footwell in the vehicle interior. A cover 1 of the ventilation device is made of polymer plastic and serves to cover an upper side of the footwell. An air duct for guiding air to be blown out into the footwell is guided in the cover 1 along a transverse axis of the vehicle. The cover 1 also has a first air outlet 3 for blowing air vertically downwards into the footwell and a second air outlet 5 for blowing air horizontally towards the knees and thighs of an occupant, wherein the second air outlet 5 is integrated into the cover 1 without any material protrusion from a flat underside of the cover 1. The air conditioned by an air conditioning system of the vehicle is guided through the air duct in order to discharge the air at the first air outlet 3 and the second air outlet 5.The first air outlet 3 is arranged in front of the second air outlet 5 in the main direction of travel. The first air outlet 3 and the second air outlet 5 differ in that the first air outlet 3 generates a normal flow towards the floor in the footwell, i.e. the feet are ventilated when an occupant is present, whereas the second air outlet 5 has a special aerodynamic shape which makes use of the Coanda effect, so that the air flowing out there has a horizontal flow direction. The respective outflow directions from the first air outlet 3 and from the second air outlet 5 are shown in the . Fig. 1 is indicated by dashed arrows. While the air discharged from the first air outlet 3 flows downward toward the feet and floor in the footwell, the air discharged from the second air outlet 5 flows horizontally toward the knees and thighs of the occupant below an instrument panel in the vehicle interior.

[0035] Fig. 2 shows a perspective view of parts of the ventilation device from the Fig. 1. This shows a perspective view of the top of the cover 1, which is otherwise not visible to an occupant. The curved, dashed arrow shows the flow of air from an air conditioning system in the vehicle towards an air duct in the cover 1. The air flows on to three first air outlets 3, shown as examples, and a further two second air outlets 5, shown as examples. While the air flowing in the air duct simply flows out through the first air outlets 3 towards the floor of the footwell due to its local overpressure compared to the footwell of the vehicle, the air at the second air outlets 5 follows a correspondingly curved contour using the Coanda effect, in order to flow horizontally towards the knees and thighs after flowing out through the second air outlets 5.

[0036] Fig. 3 again shows in perspective the cover 1 of the Fig. 2, as it faces a footwell. By arranging the first air outlets 3 in a first row and the second air outlets 5 in a second row, with the first row directed towards the front of the vehicle and the second row towards the rear of the vehicle, the outflowing air masses of the air outlets 3, 5 do not interfere with one another. In addition, all of the air outlets 3, 5 are arranged in a checkerboard pattern, i.e. the air outlets 3, 5 are arranged in their rows such that a first air outlet 3 and a second air outlet 5 are not adjacent to one another, but are arranged offset from one another. This advantageously prevents the outflowing air masses of the air outlets 3, 5 from significantly influencing one another. In addition, this enables easier integration of the air outlets 3, 5 into the one-piece plastic part of the cover 1.Also integrated into the plastic part are Coanda guide vanes 7 of the air outlets 5, which create the horizontal air flow at the outlet of the second air outlets 5. These are shown in more detail using an example in the . Fig. 4 explained.

[0037] Fig.4 shows a second air outlet 5, which is recessed into the cover 1. A Coanda guide vane 7 is arranged leading away from the underside of the cover 1, so as to avoid the need for any components protruding from the underside of the cover 1. The Coanda guide vane 7 has a convexly curved shape along the flow of the air to be blown out, which converges in the flow direction to a horizontal plane. The air guided by the air duct in the cover 1 strikes the convexly curved underside of the Coanda guide vane 7 and follows this contour according to the Coanda effect, instead of flowing out vertically downwards as in the case of the first air outlet 3. The Coanda guide vane 7 is accommodated in a bulge 9 of the cover 1 or, optionally, in a component designed separately from the cover 1, an upper shell with the bulge 9.

[0038] Although the invention has been illustrated and explained in detail by preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of variations exist. It is also clear that exemplary embodiments are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. List of reference symbols 1 cover 3 first air outlet 5 second air outlet 7 Coanda guide vane 9 Bulging

Claims

[1] Ventilation device for ventilating a footwell of a vehicle, comprising a cover (1) for covering an upper side of the footwell and comprising an air duct guided along the cover (1) for guiding air to be blown out into the footwell, wherein the cover (1) has a first air outlet (3) for blowing the air vertically downwards into the footwell and a second air outlet (5) for blowing the air horizontally towards the knees and thighs of an occupant, wherein the second air outlet (5) is integrated into the cover (1) without any material projection from a flat underside of the cover (1), characterized byin that the second air outlet (5) has a Coanda guide vane (7) sunk into the cover (1), wherein the Coanda guide vane (7) has a shape which is convexly curved along the flow of the air to be blown out and which converges in the flow direction towards a horizontal plane, and the Coanda guide vane (7) is designed in one piece with the rest of the cover (1). [2] Ventilation device according to claim 1, wherein the cover (1) has at least two first air outlets (3) in a first row and at least two second air outlets (5) in a second row, the first row and the second row running parallel to each other along a vehicle transverse axis. [3] Ventilation device according to claim 2, wherein the at least two first air outlets (3) and the at least two second air outlets (5) are each arranged offset from one another, so that the at least two first air outlets (3) and the at least two second air outlets (5) are arranged in a checkerboard pattern with respect to one another. [4] Ventilation device according to one of the preceding claims, wherein the air duct is arranged between the cover (1) and an upper shell arranged on the cover (1). [5] Ventilation device according to one of claims 2 to 4, wherein the cover (1) has a respective bulge (9) in the region of a respective second air outlet (5) which bulges away from the footwell. [6] Ventilation device according to one of claims 2 to 5, wherein respective air guiding elements for guiding the blown-out air are arranged at the respective first air outlet (3) and / or at the respective second air outlet (5). [7] Vehicle with a ventilation device according to one of the preceding claims.

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