WO2019106101A1

WO2019106101A1 - Spoiler device with a wall comprising a means for moving air downstream of the wall

Info

Publication number: WO2019106101A1
Application number: PCT/EP2018/083034
Authority: WO
Inventors: Yoann EULALIE; Philippe Gilotte
Original assignee: Compagnie Plastic Omnium
Priority date: 2017-11-29
Filing date: 2018-11-29
Publication date: 2019-06-06
Also published as: FR3074134B1; FR3074134A1; EP3717334A1

Abstract

The invention relates to a spoiler device (10) of a motor vehicle (40) intended for being placed at the front of said vehicle (40), characterised in that it comprises a wall (20) comprising a first face (22) capable of diverting an air stream, at least one second face (24) located on the opposite side of the wall (20) with respect to the first face (22), and an air-moving means (30) guiding air into an area facing one of these two faces (22, 24).

Description

Wall deflector device comprising means for supplying air downstream of the wall

The invention relates to the field of motor vehicles, and more particularly the aerodynamic devices arranged at the front of a vehicle to reduce the aerodynamic drag generated by this vehicle.

The aerodynamic efficiency of a vehicle is usually related to the height of ground clearance. As the latter decreases, the drag also decreases.

The ground clearance of the vehicles having to remain at a height compatible with the requirements of use, it is possible to obtain a satisfactory result by lowering a deflector acting aerodynamic barrier at the front of the vehicle, deflector preferentially disposed in before wheels.

This mobile baffle can be lowered or raised depending on the driving conditions such as the speed of the vehicle or the state of the road. Publication US 7,775,582 provides an example of this type of device.

At a low speed, the deflector, which is generally a blade that can have a different shape and height depending on the vehicles equipped, is in the folded position under the front bumper, to protect it against possible shocks against obstacles, for example curbs. sidewalk. This position is therefore suitable for city traffic at low speeds or on roads with hollows and bumps.

When the speed of the vehicle reaches a threshold value, the blade is deployed, for example by a rotational movement, in order to oppose the flow of air and thus reduce the drag of the vehicle. Alternatively, this deployment can be performed by a translation in a vertical plane, as disclosed in US Patent 8,702,152.

However, such a device has disadvantages.

Deployment at a relatively high speed requires the use of actuating and holding devices in the deployed position. Such devices require high power, and they are therefore energy hungry. Indeed, the movable baffle unfolds by rotation by opposing more and more to a flow of air exerting a strong pressure. Once in the deployed position, the pressure exerted on the deflector is very important. Indeed, the pressure distribution is such that the front face is in excess pressure of the order of the dynamic pressure, and the rear face is in depression of the order of 30% -40% relative to the front face. These two effects are cumulative to form a consequent longitudinal force. For example, the pressure exerted on the deflector may be 200N at 130 km / h. In addition, this pressure can damage the deflector after many activations thereof.

As known from document US 2015/0210325, there are also baffles provided with hatches, on the face of the blade coming to oppose the flow of air, covering openings through the blade. When the vehicle reaches a threshold speed, the hatches open, allowing a portion of the air flow to flow through the blade, thereby lowering the pressure on the blade.

These hatch devices have the disadvantage of greatly reducing the performance of the baffle when the doors are open, thus adversely affecting the effect thereof on the drag force generated by the vehicle.

An object of the invention is to eliminate, or at least significantly limit the aforementioned drawbacks by proposing a deflector device capable of reducing the depression on the rear face while offering an efficiency similar or greater than that of the devices of the prior art. .

For this purpose, the subject of the invention is a deflector device for a motor vehicle intended to be placed at the front of this vehicle, characterized in that it comprises a wall comprising a first face capable of deflecting an air flow, at less a second face located opposite the wall relative to the first, and a means for supplying air leading air in an area facing one of these faces.

In this way, a new air flow is brought opposite one of the two faces of the wall, which will have the effect of either reducing the depression behind the wall (with respect to a direction of circulation of the vehicle or to deflect the flow arriving upstream of the wall (always with reference to a direction of circulation of the vehicle) .This fact, this second flow of air attenuates the pressure difference between the two zones situated opposite the first and second Therefore, this deflector device has the advantage of reducing the force that would otherwise be experienced by the blade of the deflector.

Thus, the device according to the invention reduces the power consumed by the activation device of the deflector, and thereby reduce the consumption of the vehicle, compared to a vehicle equipped with a conventional deflector. It also preserves the deflector from the harmful influence of the mechanical pressure exerted on the blade, thus increasing the life of the deflector.

Finally, it makes it possible to maintain the aerodynamic efficiency of a conventional retractable baffle, because the geometry of the face situated at the front of the blade is the same as that of a device without means for supplying air.

The deflector device according to the invention may optionally include one or more of the following characteristics:

- The air supply means conducts the air in contact with the second face;

the wall of the deflector device is movable between an extended position and a retracted position;

the device moves from the extended position to the retracted position via a rotation of the wall; the wall has a blade shape;

- The air supply means comprises at least one air inlet located upstream of the wall relative to a flow direction of the air flow, and at least one outlet located downstream and close to the wall relatively in the same direction of circulation of the air flow, the air supply means guiding the air from its inlet to its outlet;

- The air supply means comprises at least one air inlet located upstream of the wall relative to a flow direction of the air flow, and at least one outlet located upstream and close to the wall relatively in the same direction of circulation of the air flow, the air supply means guiding the air from its inlet to its outlet;

the means for supplying air is a conduit;

- The conduit has a shape adapted to accelerate the flow of air from its inlet to its outlet;

The invention also relates to a motor vehicle bumper comprising an air supply means for a deflector device as described above. The invention also relates to a front face of a motor vehicle comprising a device as described above.

Advantageously, the duct inlet is located on the front face.

We will now present an embodiment of the invention given by way of non-limiting example and with reference to the appended figures in which:

- Figure 1 is a partial view of a motor vehicle comprising a deflector device according to the prior art;

- Figure 2 is a partial view of a motor vehicle comprising a deflector device according to the invention;

FIG. 3 is a partial view of a motor vehicle comprising a deflector device according to the invention;

- Figure 4 is a partial view of a motor vehicle comprising a deflector device according to the invention, with the apparent air flow.

In what follows, reference will be made to orientation terms, such as "longitudinal axis X", "transverse axis Y", "vertical axis Z", "front", "rear", "above" , "Superior", "below", "lower", etc. These terms are understood by reference to the usual orientation of motor vehicles.

Referring now to Figure 1 which shows a deflector device of the prior art, and more specifically the evolution of a flow of air propagating around the vehicle in a direction substantially parallel to the longitudinal axis X of the vehicle automobile.

The vehicle 40 comprises a front bumper 55, as well as a rocker panel 57 equipped with a baffle device 10. It also comprises a front bumper 50 integrated into a front face 60. The rocker panel 57 is equipped with a deflector device 10. This device 10 comprises a rigid wall 20 in the form of a blade deployed by rotation about an axis 26 situated at the part of the deflector device 10 fixed to the underbody 57. As described above, such a blade is folded under the bottom of body 57 of the vehicle 40 at low speed and is deployed when the vehicle 40 reaches a high speed. We observe the creation of a vacuum zone 76 behind the deflector device 10 deployed. As explained above, this leads in part to the exercise of a significant effort on the deflector device 10, force oriented along the longitudinal axis X of the vehicle and directed rearwardly thereof.

We will now present Figures 2 and 3 which illustrate a deflector device 10 according to the invention. FIG. 2 illustrates a deflector device 10 installed on a motor vehicle 40, and in an extended position. Figure 3 illustrates the same deflector device 10, this time in a retracted position. The references and terms used in the description of the device of the prior art will also be used.

This deflector device 10 of a motor vehicle, placed at the front of this vehicle comprises a wall 20 comprising a first face 22 capable of deflecting an air flow, a second face 24 located opposite the wall 20 with respect to the first 22, and an air supply means 30 leading air into contact with the second face 24. The air supply means 30 here makes it possible to inject a stream of air (only visible in FIG. 4 and which will be discussed later) in contact with the second face 24. By "in contact with the second face 24", we mean that all or part of the flow is brought directly close to the second face 24 of the wall 20 .

The wall 20 of the deflector device 10 is movable between an extended position, illustrated in FIG. 2, and a retracted position illustrated in FIG. 3. The wall 20 has a rectangular shape, its length extending along the transverse axis Y of the vehicle 40 In the deployed position, the wall 20 forms an almost straight angle with the underbody 57 of the vehicle 40. Thus, the wall 20 is oriented vertically along its width. In this way, the wall 20 is in a position allowing a redirection of airflow arriving from the front of the vehicle when it is in motion. This flow is deflected by a first face 22 of the wall 20. In retracted position, the second face of the wall 24 is pressed against the underside 57 of the vehicle. In this position, used when the vehicle is traveling at low speed, the device is protected from shocks with protruding elements of the road, such as sidewalks for example. In this position, the wall can obstruct the outlet 36 of the air supply means 30, but this outlet 36 can equally well be placed so as not to be obstructed by the wall 20 when the deflector 10 is in the retracted position .

The deflector device 10 moves from an extended position to a retracted position via a rotation of the wall 20. This rotation of the wall can be a simple rotation by relative to the body of the vehicle 40, according to axis of rotation 26 located at the rocker 57. This axis 26 is oriented along the transverse axis Y of the vehicle 40. This simple rotation simplifies the implementation of the link between the wall and the vehicle body. Thus, the activation of the movement of the wall is made from a simple, lightweight and inexpensive mechanism. Alternatively, the deployment of the wall can also be done in a movement composed of several rotations along several axes. Still alternatively, the deployment of the wall 20 can be effected by a simple translation thereof along the vertical axis Z, with respect to the vehicle 40.

The wall 20 of the deflector device 10 advantageously has a blade shape. That is to say that its general shape is that of a rectangular parallelepiped with, with reference to its position in Figure 2, its length oriented along the transverse axis Y of the vehicle, its width oriented along the vertical axis Z, and its height oriented along the longitudinal axis X. The length of the blade is its largest dimension. The height of the blade is much lower than the others of its dimensions. This geometry of the wall 20 is thus adequate to both deflect an air flow when the wall 20 is in the deployed position and take the least space when the wall 20 is in the retracted position. Therefore, the wall 20 does not form a protuberance of the rocker 57 in this position, and does not require the fitting of a cavity therein. Thus, the wall does not deviate a flow of air outside the vehicle 40 when the latter is in the retracted position. However, it is possible to arrange a cavity, for example when the wall 20 is too thick, to accommodate the wall 20 in the retracted position.

The air supply means 30 comprises at least one air inlet 34 which is located upstream of the wall 20. By upstream means that the air supply means 30 is located before the wall 20 relative to a direction of flow of the air flow, so towards the front of the vehicle 40, to the left in FIGS. 1 to 4. The device is provided with at least one outlet 36 situated downstream and close to the wall 20 relative to the same direction of flow of the air flow. The outlet 36 is located just above the wall 20. The air supply means 30 guides the air from its inlet 34 to its outlet 36, in contact with the wall 20. This geometry of the supply means air 30 allows it to bring air directly there a depression would have formed in a device of the prior art (as shown in Figure 1). Thus, it makes it possible to reduce this depression behind the wall 20, and therefore to reduce the high mechanical stress experienced by it. In this way, the device 10 requires a much lower energy for its deployment and for maintaining it in the deployed position than the devices of the prior art. In addition, the wall undergoing less mechanical stress, it can be lighter, and has lower risks of being damaged by the pressure of the air flow, for example being bent by the pressure exerted by them . In another embodiment of the invention, the device is provided with at least one outlet located upstream of the wall 20, relative to the direction of flow of the air flow outside the vehicle. The outlet of the air supply means 30 is located facing the first face 22 of the wall 20. Thus the air supply means 30 ejects air upstream of the wall 20. Therefore a flow of air outside the vehicle, and upstream of the wall 20, is deflected by a flow of air leaving the air supply means 20, to come between the wall 20 and the roadway on which the vehicle circulates. Therefore, the pressure of the air in an area facing the first face 22 of the wall 20 is decreased. Thus, the aerodynamic forces experienced by the wall 20 are reduced. Therefore, the wall 20, and its connection with the rocker 57 are less likely to be damaged by these mechanical forces.

The air supply means 30 is here a conduit 32. By conduit is meant a closed channel being open only at its inlet ends 34 and outlet 36. Such a conduit 32 can bring the air without having to use other means, and even without using extra energy to move the air. Indeed, it is the movement of the air with respect to the vehicle 40, when it is in motion, which brings the air into contact with the wall 20. It is therefore directed by the supply means of air 30. Such a conduit makes it possible not to need to use air movement device, such as a compressor for example, and thus allows the deflector device 10 to consume little energy and to require little maintenance.

It is possible to have an air supply means 30 comprising two, three ducts 32 or even more. In addition, it can also comprise two or more outlet apertures 36, as well as two or more flux inlet openings 34. Advantageously, the means 30 comprises two ducts 32 each having an outlet 36 and an inlet 34.

The conduit 32 may also have a shape capable of accelerating the flow of air from its inlet 34 to its outlet 36. This shape may be a reduction of the section of the duct 32 allowing an acceleration of the air flow therethrough. Thus, this makes it possible to send air with a greater velocity into the depression zone formed behind the wall 20, and thus to better reduce the depression formed behind the wall 20.

The air supply means 30 is integrated in the bumper 50 of the vehicle 40. Thus, the conduit 32 is arranged in the bumper 50 and is part of it. The bumper 50 and the air supply means 30 therefore form the same part of the vehicle 40. However, alternatively, the air supply means 30 and the bumper 50 may constitute two different parts.

The deflector device is integrated in the front face 60 of the vehicle 40. The air inlet 34 of the duct 32 is located on the front face 60. This inlet 34 is preferably on an outer surface located at the front of the vehicle 40 along the longitudinal axis X of the vehicle. We will now describe the behavior of air flows in and around the device, in support of Figure 4, on which these flows are visible. This figure illustrates the deflector device shown in Figures 2 and 3, so we will describe here only the elements that do not appear in Figures 2 and 3. In this figure, the deflector device appears in an extended position similar to that of the figure 2.

This figure shows a set of air flows outside the vehicle 70. These flows bypass the front face 60 either from above, passing over the hood of the vehicle (not shown), or by the sides along the transverse axis Y (not shown), either from below, bypassing the front bumper 55, and passing under the rocker 57. The flows are deflected by the first face 22 of the wall 20 of the deflector device 10. In this way , the wall 20 is opposed to the flow of air outside the vehicle 70 and causes a reduction of the drag of it. The air supply means 30, which is here a duct 32, captures part of the outside air flows 70 through its inlet 34. Thus, a through-air flow 72 takes the duct from its inlet 34 to its Exit 36. During this path from the inlet 34 to the outlet 36, the throughflow 72 may optionally be accelerated. This acceleration of the speed of this stream 72 can be obtained by means of, for example, a reduction of the section orthogonal to the stream 72 of the duct 32.

The flow of through air 72, after having traversed the duct 32, comes out of the latter through the outlet 36. It thus becomes the outgoing air flow 74. This flow 74 is supplied by the air supply means 30 in contact with the second face 24 of the wall 20. Thus, the outflow 74 comes directly into what was the depression zone 76 in the device of the prior art shown in FIG. 1. As a result, the outgoing flow This depression decreases very strongly, even eliminates, this depression behind the wall 20. Thus, the mechanical forces undergone by it are greatly reduced and the energy required for deployment and holding in the deployed position of the wall are greatly reduced. In addition, the wall 20 and its connection with the rocker 57 are less likely to be damaged by these mechanical forces. By the same, it requires less maintenance.

The invention is not limited to the embodiments presented and other embodiments will become apparent to those skilled in the art. Nomenclature

10: deflector device

20: wall

22: first face of the wall

24: second face of the wall

26: axis of rotation of the blade

30: means for supplying air

32: led

34: inlet of the air supply means

36: outlet of the air supply means

40: motor vehicle

50: front bumper of the vehicle

55: front bumper of the vehicle

57: rocker

60: front of the vehicle

70: air flow outside the vehicle

72: air flow through the duct

74: airflow leaving the duct

76: depression behind the blade

Claims

claims

A deflector device (10) for a motor vehicle (40) intended to be placed at the front of this vehicle (40), characterized in that it comprises a wall (20), which has a blade shape, movable between a deployed position and a retracted position, comprising: a first face (22) adapted to deflect an air flow, at least a second face (24) located opposite the wall (20) relative to the first (22); ), and an air supply means (30) conducting air in an area facing one of these faces (22, 24).

2. Device (10) according to the preceding claim wherein the air supply means (30) conducts the air in contact with the second face (24).

3. Device (10) according to one of the preceding claims which passes from the extended position to the retracted position via a rotation of the wall (20).

4. Device (10) according to one of the preceding claims wherein the air supply means (30) comprises at least one air inlet (34) located upstream of the wall (20) relative to a direction. for circulating the air flow, and at least one outlet (36) located downstream and close to the wall (20) relative to the flow direction of the air flow, the air supply means (30) guiding air from its inlet (34) to its outlet (36).

5. Device (10) according to one of the preceding claims wherein the air supply means (30) comprises at least one air inlet (34) located upstream of the wall (20) relative to a direction. of the flow of air, and at least one outlet (36) located upstream and close to the wall (20) relative to the same direction of flow of the air flow, the means for supplying air (30) ) guiding the air from its inlet to its outlet (36).

6. Device (10) according to one of the preceding claims wherein the air supply means (30) is a conduit (32).

7. Device (10) according to the preceding claim wherein the conduit has a shape adapted to accelerate the flow of air from its inlet (34) to its outlet (36).

8. Bumper (50) of a motor vehicle comprising an air supply means (30) for a baffle device (10) according to one of the preceding claims.

9. Front face (60) of a motor vehicle (40) comprising a device (10) according to one of claims 4 and 5.

10. Front face (60) according to the preceding claim wherein the duct inlet (32) is located on the front face (60).