Rotating quarter window deflector coupled to a duct

Abstract

This device for reducing the drag force (Fx) and yaw moment (Mz) of a motor vehicle comprises a movable quarter panel deflector (10) (11) and a variable-geometry duct (12) formed between the quarter panel (11) and the deflector (10). It includes two openings (21, 22) located in the same plane (xOy), parallel to the ground when the vehicle is in use, the openings (21, 22) being contiguous respectively to the quarter panel (11) and the rear window (15) of the motor vehicle. Figure for the abbreviation: Fig 2

Description

Title of the invention: Rotating quarter window deflector coupled to a duct technical field

[0001] The invention relates, in general, to systems for reducing aerodynamic coefficients and improving the stability of a motor vehicle subjected to a lateral wind.

[0002] A particularly interesting application of the invention concerns vehicles whose rear window is of the straight base type, for which the invention makes it possible to reduce their drag force and improve their stability under lateral wind without significantly altering their design.

[0003] However, the invention also applies to any other motor vehicle regardless of the shape of its rear window. Previous techniques

[0004] Drag force is generally defined as a force that opposes the motion of an object in a fluid, in this case a vehicle in the air. In Figure 1, it is denoted Fx and is oriented in the opposite direction to the motion of the vehicle. It is a component of the aerodynamic wrench.

[0005] It creates a constant braking force and therefore induces unnecessary fuel consumption for internal combustion vehicles and a reduction in range for electric vehicles.

[0006] Yaw moment occurs when the rear of a vehicle is not subjected to the same lateral force as the front of the vehicle. The yaw moment, denoted Mz, therefore increases in the presence of a crosswind 1, for example, due to obstacles on the side of the road, entering or exiting a tunnel, overtaking vehicles, or simply a constant crosswind.

[0007] In Figure 1, the flow near the vehicle is asymmetrical. This results in greater lateral forces at the front 2 than at the rear 3. The vehicle is thus subjected to the moment Mz which causes it to deflect towards its leeward side 4. The opposite side is called the windward side 5.

[0008] In such situations, the vehicle then presents a skid angle noted [3. This is a situation known as skidding which requires constant correction by the driver and causes a lack of comfort and insecurity for the latter.

[0009] Existing devices such as ducts placed on the motor vehicle make it possible to reduce the vehicle's drag.

[0010] Similarly, deflectors allow air to exert pressures on the vehicle at specific points in order to improve its stability or aerodynamics under small skid angle, but these do not offer sufficient stability under crosswind at an angle of more than 10° relative to the direction of the vehicle.

[0011] A vehicle is said to have a large skid angle when the crosswind is at an angle of more than 10° to the direction of the vehicle. Below this angle, it is considered a small skid angle. Description of the invention

[0012] The present invention therefore aims to overcome the disadvantages of the aforementioned systems and to improve the reduction of the quantities previously described.

[0013] The invention therefore relates to a device for reducing the drag force and yaw moment of a motor vehicle, comprising a movable quarter window deflector and a conduit formed between the quarter window and the deflector and comprising two vertical openings, the openings being contiguous respectively to the quarter window and the rear window of the motor vehicle.

[0014] Thus, combining the duct with a movable deflector allows for a greater range of possibilities, particularly in the angle adopted by the deflector, and therefore better vehicle stabilization under high skid angles. Furthermore, drag is reduced at a small skid angle, especially if a device is present on each side of the vehicle, which can then benefit from a narrower rear quarter panel, promoting better aerodynamics. Finally, this narrowing does not alter the vehicle's design since the deflector is placed on top and can be constructed in such a way as to maintain a pre-defined design.

[0015] Advantageously, the movable quarter panel deflector includes means for modifying the geometry of the duct which vary according to the position of the deflector.

[0016] Advantageously, according to a first embodiment, the deflector includes a motorized pivot, the axis of rotation of which forms an angle greater than 60° with the plane in which the duct evolves, capable of orienting the deflector according to a rotation range of approximately 40° in total and of moving it from a position where the opening of the duct contiguous to the rear window is closed to a position where it is not.

[0017] Advantageously, and according to a second embodiment, the deflector comprises at least one rail placed in a plane parallel to the ground when the vehicle is in use and capable of moving the deflector by translation from a position where the opening of the duct contiguous to the rear window is closed to a position where it is not.

[0018] Advantageously, the device includes means for detecting skidding situations.

[0019] The invention also relates to a motor vehicle, comprising at least one device for reducing drag force and yaw moment according to the characteristics- risks mentioned previously. Brief description of the drawings

[0020] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0021] [fig. 1] which has already been mentioned, illustrates a motor vehicle associated with an orthonormal frame and subjected to a lateral wind;

[0022] [fig.2] illustrates a movable quarter window deflector thanks to a rotating pivot according to the invention, placed at the rear left of a vehicle and viewed from the front left side;

[0023] [fig.3] illustrates a movable quarter window deflector thanks to a rotating pivot according to the invention, placed at the rear left of a vehicle and viewed from the left side;

[0024] [fig.4] illustrates a quarter window deflector according to the invention in an extreme position of use, mobile thanks to a rotating pivot and placed at the rear left of a vehicle and viewed from the rear left; and

[0025] [fig.5] illustrates a quarter panel deflector according to the invention, movable by means of rails of translation. Detailed description of at least one embodiment

[0026] In the present description of the device for reducing the drag force and yaw moment of a motor vehicle, it should be specified that the characteristics relate to a device placed on the left rear quarter panel of a vehicle, and that this device achieves its objective of reducing the drag force and yaw moment only if a second device of the same type is placed on the right rear quarter panel.

[0027] Furthermore, this device can be installed, assembled, or machined during the construction of the vehicle body.

[0028] Figure 2 schematically represents the device according to the invention comprising a movable deflector 10 of the quarter panel 11 and a conduit 12 seen from the front left side of a motor vehicle and according to an embodiment including a rotating pivot 13 in the deflector 10.

[0029] The duct 12 is formed between the quarter panel 11, the rear of which 14 is machined to obtain a narrower quarter panel profile for improved aerodynamics, and the movable deflector 10. This type of duct 12 is particularly effective when the rear window 15 (Figure 3) of the vehicle is of the straight-set type, with the angle of the window 15 relative to the ground when the vehicle is in use exceeding 40°. In this configuration, the duct 12 reduces the vehicle's drag force. Furthermore, the device includes means 10 for modifying the geometry of the duct, consisting of the deflector 10, the latter being movable and able to, depending on its position affect the geometry of the duct when the vehicle is in motion.

[0030] On the other hand, for a rear window 15 making an angle with respect to the ground of less than 17° when the vehicle is in use, the drag force Fx is not affected by the presence of the duct 12. In this configuration, the deflector 10 nevertheless provides a gain in stability under a large skid angle [3, resulting from a reduction in the yaw moment, particularly around a skid angle [3 of about 20°.

[0031] The duct 12 has two openings 21 and 22 which together with the duct 12 form an air passage with an inlet and an outlet. They are located in the same plane (xOy), parallel to the ground when the vehicle is in use.

[0032] The opening 21 adjacent to the quarter panel 11 includes the air intake when the vehicle is being used in a forward direction. For example, it has dimensions of 230 millimeters x 40 millimeters.

[0033] The conduit 12 measures between 230 and 460 millimeters in length approximately and is located so that there are at least two points, each located at a different opening, which can be contained in a plane parallel to the ground when the vehicle is in use (xOy plane of Figure 1).

[0034] The opening 22 adjacent to the rear window 15 of the vehicle includes the air outlet of the duct 12 when the vehicle is being used in a forward direction. Its dimensions are, for example, 200 millimeters x 65 millimeters.

[0035] The surface of the deflector 10 has, for example, a streamlined shape of the type of airplane wing or may, for example, contain edges.

[0036] The deflector 10 is orientable by means of a rotating pivot 13, visible in Figure 3, which can be positioned towards the center of the deflector 10 so as to allow the deflector 10 to be rotated through a range of 40°, with extreme angles of 20° in one direction (visible in Figure 4) and 20° in the other direction, around a neutral position of 0° (visible in Figure 2). The pivot 13 is actuated by a motor 23, located, for example, above or below the deflector. Its axis of rotation forms an angle greater than 60° with the xOy plane in which the duct moves.

[0037] In the case where the vehicle is subjected to a small angle of skidding [3, the deflector 10 is oriented with an angle close to [3, the drag force Fx is then reduced by the presence of the duct 10 and the position of the deflector 10.

[0038] In the event that the vehicle is subjected to a large sideslip angle [3], the deflector 10 can be oriented up to an angle of 20°, in order to maximize the pressure exerted on the rear surface of the windward side 5 of the vehicle and to reduce the yaw moment Mz. Figure 4 illustrates the position of the deflector 10 when the large-angle crosswind is coming from the left of the vehicle. Under a large sideslip angle [3], reducing the drag force Fx is no longer the priority, hence a potential blockage of the duct 12 by the deflector 10 when the latter is oriented at 20° in one direction.

[0039] According to another embodiment visible in figure 5, the rotating pivot is replaced by rails 25 allowing the mobility of the deflector 10 according to the skid angle

[0040] The orientation of the deflector is triggered by various systems 26 for detecting and anticipating skidding situations, including pressure sensors and accelerometers.

Claims

Demands

1. A device for reducing the drag force (Fx) and yaw moment (Mz) of a motor vehicle, characterized in that it comprises a movable quarter window deflector (10) (11) and a conduit (12) formed between the quarter window (11) and the deflector (10) and comprising two openings (21, 22) placed in the same plane (xOy), parallel to the ground when the vehicle is in use, the openings (21,22) being contiguous respectively to the quarter window (11) and the rear window (15) of the motor vehicle.

2. Device, according to claim 1, wherein the movable quarter-view deflector (10) (11) includes means (10) for modifying the geometry of the duct which varies according to the position of the deflector (10).

3. Device, according to any one of claims 1 and 2, in which the deflector (10) comprises a motorized pivot (13), the axis of rotation of which forms an angle greater than 60° with the plane (xOy) in which the conduit (12) evolves, capable of orienting the deflector (10) according to a rotation range of about 40° in total and of moving it from a position where the opening (22) of the conduit (12) contiguous to the rear window (15) is closed to a position where it is not.

4. Device, according to any one of claims 1 and 2, wherein the deflector comprises at least one rail (25) placed in a plane (xOy) parallel to the ground when the vehicle is in use and capable of moving the deflector by translation from a position where the opening of the duct adjacent to the rear window is closed to a position where it is not.

5. Device, according to any one of claims 1 to 4, comprising means (26) for detecting skidding situations.

6. Motor vehicle, characterized in that it comprises at least one device for reducing drag force and yaw moment according to any one of claims 1 to 5.

Images