Underbody paneling with directed ventilation for an electric vehicle

Abstract

The invention relates to a vehicle (1) with an air guidance system for flow control on an underbody of the vehicle (1), comprising an air duct with a heat exchanger (3) for cooling an electrical component of the vehicle (1) and with a blower (5) for drawing in ambient air and guiding the ambient air to the heat exchanger (3), wherein the air duct has an air inlet and, in the direction of flow after the heat exchanger (3), an air outlet (7) on an underbody element of the air guidance system, wherein the air outlet (7) is oriented horizontally along the underbody and away from the air inlet for blowing out at least a part of the air guided in the air duct.

Description

[0001] The invention relates to a vehicle with an air guidance system for flow control on an underbody of the vehicle, as well as a method for charging a battery of a battery-electric vehicle.

[0002] In electric vehicles, especially battery-electric vehicles, a large proportion of warm engine compartment air is typically vented through the wheel wells at the front of the vehicle. When stationary, this warm engine compartment air can escape under the vehicle via the wheel wells and flow along the underbody paneling in front of the vehicle. When the vehicle's cooling fan is switched on, the fan therefore draws in not only cool ambient air through the vehicle's heat exchanger but also some of this warm engine compartment air.

[0003] If this effect occurs, the cooling capacity of the vehicle's cooling and air conditioning system is reduced when stationary, as the heat exchanger for this system is partially exposed to warm engine compartment air. However, battery-electric vehicles, in particular, may require very high cooling capacity when stationary, especially during fast charging with active cabin climate control, particularly in warm weather. Insufficient cooling capacity can lead to consequences such as increased battery charging time or elevated cabin temperature.

[0004] In the prior art, it is known to optimize the underbody airflow and the airflow under the hood for the driving of a vehicle in such a way as to maximize the performance of a cooling system with a heat exchanger of an electric vehicle.

[0005] In this context, DE 20 2016 102 751 U1 relates to an underbody air and heat management system for a motor vehicle, comprising: an aerodynamic fairing that includes a flap system which can be selectively moved between an open position and a closed position; a spoiler which can be selectively moved between a basic position and an extended position; and a control system for moving the flap system between the open position and the closed position and the spoiler between the basic position and the extended position.The spoiler is positioned in front of the flap system, particularly in the direction of travel, so that when the spoiler is in the extended position, it forms a low-pressure area on the underside of the flap system to improve the airflow from the engine compartment area under the hood through the flap system when the vehicle is moving forward.

[0006] DE 10 2018 114 499 A1 relates to a motor vehicle front end with a heat exchanger, a motorized fan associated with the heat exchanger, and a two-path cooling air system for controlling the air supply to the heat exchanger, wherein the cooling air system comprises: an upper air inlet opening opening substantially forward, an upper flap arrangement associated with it and actuated by a motor, a lower air inlet opening opening substantially downward, and a lower flap arrangement associated with it and actuated by a motor, wherein both air inlet openings are arranged upstream of the heat exchanger, and a lower air outlet is provided downstream of the heat exchanger in the underbody of the vehicle.

[0007] JP 2013-180614A further relates to a temperature control structure for a vehicle battery to prevent a decrease in battery performance at low temperatures. For this purpose, a cooling fan is arranged behind a cooling unit, running through the cooling unit from front to back and generating an airflow that exits to the outside of the vehicle through an outlet opening in a floor tunnel.

[0008] CN 107650826 A also relates to an underbody protection plate that integrates a controllable switch structure, with numerous ventilation slots in the corresponding area of ​​the engine compartment. A ventilation system for heat management in the engine compartment is equipped with an underbody protection plate that is controlled by the control unit for opening and closing.

[0009] DE 10 2020 110 272 A1 further relates to an electrically powered motor vehicle with a cooling system for dissipating waste heat generated during the charging of a traction battery of the motor vehicle, comprising at least one cooling circuit for dissipating the waste heat generated during charging via a cooling medium; at least one radiator connected to the cooling circuit for dissipating the waste heat absorbed by the cooling medium to a vehicle environment; at least one main fan for supplying fresh air to the radiator, wherein the cooling medium, as it flows through the radiator, transfers the absorbed waste heat to the fresh air flowing around the radiator, after which this air, promoted by the main fan, flows away from the radiator in the form of exhaust air heated by the waste heat;at least one auxiliary fan installed in the motor vehicle, designed to, at least when the motor vehicle is stationary and the auxiliary fan is activated, to work together with the main fan to convey the exhaust air from the motor vehicle into the vehicle environment in such a way that re-intake of the exhaust air by the main fan is prevented.

[0010] The object of the invention is to improve the cooling of a battery-electric vehicle when stationary, particularly during a charging process.

[0011] The invention is defined by the features of the independent claims. Advantageous further developments and embodiments are the subject of the dependent claims.

[0012] A first aspect of the invention relates to a vehicle with an air guidance system for flow direction on an underbody of the vehicle, comprising an air duct with a heat exchanger for cooling an electrical component of the vehicle and with a blower for drawing in ambient air and directing the ambient air to the heat exchanger, wherein the air duct has an air inlet and, in the direction of flow downstream of the heat exchanger, an air outlet on an underbody element of the air guidance system, wherein the air outlet is oriented horizontally along the underbody and away from the air inlet for blowing out at least a portion of the air guided in the air duct and has one or more slots which have a horizontal component, so that the flow of hot air through the air outlet is directed horizontally along the underbody towards the rear of the vehicle by the Coandé effect.

[0013] The air outlet, preferably designed as a vent slot directed towards the rear of the vehicle, is arranged on an underbody element of an underbody panel and serves to selectively expel a portion of warm engine compartment air in order to transport another portion of warm engine compartment air, which enters the underbody via the wheel wells, towards the rear of the vehicle. The expulsion through the air outlet creates a momentum on the underside of the vehicle, thus generating a flow towards the rear. This flow also transports warm engine compartment air, which enters the underbody via the wheel wells, towards the rear of the vehicle, thereby preventing this warm engine compartment air from being drawn in at the air intake of the air duct.

[0014] The desired cooling performance of the air distribution system is thus reliably ensured. Fast charging times can be guaranteed, and the fan speed of the blower can remain low, which keeps noise and vibrations in the vehicle to a minimum. Furthermore, the fan power of the blower or the heat exchanger can be reduced if necessary.

[0015] According to an advantageous embodiment, the vehicle is a battery-electric vehicle.

[0016] According to another advantageous embodiment, the air inlet is oriented to draw in ambient air in front of the vehicle front.

[0017] According to another advantageous embodiment, the air inlet is horizontally oriented.

[0018] According to another advantageous embodiment, the air outlet is oriented towards the rear of the vehicle for blowing out the air.

[0019] According to another advantageous embodiment, the air outlet is formed by slots in the underfloor element.

[0020] According to another advantageous embodiment, the slots can be closed.

[0021] According to a further advantageous embodiment, the vehicle also has an outlet which serves to direct a portion of the air guided in the air duct in the direction of flow after the heat exchanger via a wheel arch of the vehicle into the environment.

[0022] Another aspect of the invention relates to a method for charging a battery of a battery-electric vehicle, wherein ambient air is drawn in by a blower, guided through an air duct to a heat exchanger, and, with respect to the flow direction in the air duct, is blown out at least partially behind the heat exchanger through an air outlet horizontally along and below the underbody and away from the air inlet in the direction of a vehicle rear through one or more slots which have a horizontal component, wherein the hot air flowing through the air outlet is guided horizontally along the underbody in the direction of a vehicle rear by the Coandé effect.

[0023] The air outlet can be designed to be closable, in order to be able to close it, particularly in certain driving conditions of the vehicle or when the vehicle is stationary, at least when the vehicle is not being loaded.

[0024] According to a further advantageous embodiment, the air outlet is opened for a period of time during battery charging and closed during at least some driving phases of forward travel by the vehicle and / or when the vehicle is parked without charging.

[0025] Advantages and preferred further developments of the proposed procedure result from an analogous and substantive transfer of the above statements made in connection with the proposed vehicle.

[0026] Further advantages, features and details will become apparent from the following description, in which - possibly with reference to the drawing - at least one embodiment is described in detail.

[0027] They show: Fig. 1: An example of a battery-electric vehicle. Fig. 2: From a perspective, a part of a vehicle with an exemplary underbody according to the state of the art. Fig. 3: A sectional view of the part of the vehicle that Fig. 2. Fig. 4: Perspective view of the underbody of a vehicle according to an embodiment of the invention. Fig. 5: A sectional view of the part of the vehicle that Fig. 4.

[0028] The representations in the figures are schematic and not to scale.

[0029] Fig. Figure 1 shows a battery-electric vehicle 1. At the front of the vehicle 1, an engine compartment is provided, which is covered at the bottom by an underbody panel. Concealed by external body components, a heat exchanger is located inside the vehicle 1. This heat exchanger is positioned in an air duct to draw in relatively cooler ambient air and pass it through the heat exchanger, which is connected to a hot component of the battery-electric vehicle 1. The intake air is heated, and the extracted heat is used to cool the hot component of the battery-electric vehicle 1. Typically, the already heated air is directed downstream of the heat exchanger towards the wheel wells, where it is released into the environment. Fig. Section 2 shows further details.

[0030] Fig. Figure 2 shows a perspective view looking towards the left wheel in the upper part of the image and the underbody, extending to the right wheel of vehicle 1 in the lower part. The dashed arrows indicate the flow of air, heated by the heat exchanger and discharged through the respective vents at the wheel arches, in an area beneath the underbody, under the engine compartment, and along the sides of vehicle 1. While some of the warm air flows out to the sides of vehicle 1 after exiting the air duct, some may flow towards the rear of the vehicle along the underbody. A portion may also flow towards the front of the vehicle, potentially reaching an air intake of the air duct. This would cause the hot air discharged from the vents to be drawn back in through the air intake, reducing the cooling capacity of the heat exchanger.

[0031] Fig. Figure 3 shows a sectional view of part 1 of the vehicle. Fig. 2. The same perspective applies here as in Fig. Vehicle 1 is shown in section at its front. The dashed arrows again indicate a possible airflow from the air inlet of the air duct, through the heat exchanger 3 and the blower 5 (which generates the airflow), through an air outlet to the underbody. Furthermore, a possible flow component along the underbody is sketched, from an outlet behind the heat exchanger 3, via a wheel arch (wheel housing), back to the air inlet of the air duct.

[0032] Fig. Figure 4 shows a configuration according to the invention for solving the problem in Fig. 2 to Fig. Problem 3 shown. Here, a perspective view of vehicle 1 is again shown first, analogous to the representation of the Fig. 2. In contrast to the configuration of Fig. However, in this case, an air outlet 7 is provided on an underbody element in addition to the vents in the wheel wells. The air outlet 7 has one or more slots with a horizontal component. Furthermore, the Coandé effect can be applied to guide the hot air flowing through the air outlet 7 as horizontally as possible along the underbody towards the rear of the vehicle. This flow, directed out through the air outlet 7, carries the hot air flowing out through the vents in the wheel wells along the underbody of the vehicle 1 towards the rear of the vehicle and prevents the hot air that escaped into the environment via the wheel wells from flowing back from the air duct behind the heat exchanger 3 to the air inlet of the air duct.

[0033] Fig. Figure 5 shows a cross-section of part 1 of the vehicle, as shown in Fig. 4 shown. The cross-sectional view corresponds to the representation of the Fig. 3, however, the air outlet 7 according to the invention is shown. The air blown out through the air outlet 7 towards the underbody of the vehicle 1, with its main horizontal component in the direction of the rear of the vehicle, carries along possible proportions of air heated by the heat exchanger 3 from the air duct, which escapes into the environment via the wheel wells, laterally along the vehicle 1 and / or below the underbody in the direction of the rear of the vehicle, depending on where the hot air flowing from the wheel wells goes.

[0034] Although the invention has been further illustrated and explained in detail by means of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived from them by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that a multitude of possible variations exist. It is also clear that the embodiments mentioned as examples are truly only examples and are not to be understood in any way as limiting, for example, the scope of protection, the possible applications, or the configuration of the invention.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 leaving the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. Reference symbol list 1 vehicle 3 heat exchangers 5 blowers 7 Air outlet

Claims

[1] Vehicle (1) with an air guidance system for flow control on an underbody of the vehicle (1), comprising an air duct with a heat exchanger (3) for cooling an electrical component of the vehicle (1) and with a blower (5) for drawing in ambient air and directing the ambient air to the heat exchanger (3), wherein the air duct has an air inlet and, in the direction of flow downstream of the heat exchanger (3), an air outlet (7) on an underbody element of the air guidance system, wherein the air outlet (7) is oriented horizontally along the underbody and away from the air inlet for blowing out at least a part of the air guided in the air duct and has one or more slots which have a horizontal component, so that the hot air flowing through the air outlet (7) is directed horizontally along the underbody towards the rear of the vehicle by the Coandé effect. [2] Vehicle (1) according to claim 1, wherein the vehicle (1) is a battery electric vehicle (1). [3] Vehicle (1) according to any of the preceding claims, wherein the air inlet is oriented to draw in ambient air in front of a vehicle front. [4] Vehicle (1) according to one of the preceding claims, wherein the air outlet (7) is directed towards the rear of the vehicle for blowing out the air. [5] Vehicle (1) according to one of the preceding claims, wherein the air outlet (7) is formed by slots in the underbody element. [6] Vehicle (1) according to claim 5, wherein the slots are closable. [7] Vehicle (1) according to one of the preceding claims, comprising a discharge which serves to direct a further part of the air guided in the air duct in the direction of flow after the heat exchanger (3) via a wheel house of the vehicle (1) into the environment. [8] Method for charging a battery of a battery electric vehicle (1), wherein ambient air is drawn in by a blower (5), is guided through an air duct to a heat exchanger (3) and, with reference to the flow direction in the air duct, is blown out at least partially behind the heat exchanger (3) horizontally below the underbody and away from the air inlet in the direction of a vehicle rear through one or more slots which have a horizontal component, wherein the hot air flowing through the air outlet (7) is guided horizontally along the underbody in the direction of a vehicle rear by the Coandé effect. [9] Method according to claim 8, wherein the air outlet (7) is opened for a period of time during the charging of the battery, and is closed during at least some sections of a forward journey of the vehicle (1) and / or when the vehicle (1) is parked without charging.

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